Anti-DBT ranting in audio

[jj]

http://forum.stereophile.com/forum/showflat.php?Cat=0&Number=64883&an=0&page=0#Post64883

It's a splendid example of how anti-science audiophiles behave. It has much in common with purveyors of "intellegent design", "creation science", "mind reading", and the like, I think.

Just posted as an example (it's hardly the only one, nobody's been accused of child abuse, or gotten threatening phone calls, or had quotes from other boards thrown at them, or that sort of thing, yet, in that thread) of the abusive nature of anti-science folks.

Participation is probably pointless. I've been watching the same head-in-the-sand arrogance and antagonism now for, well, since circa 1973 or 1974, give or take, and the only thing that's changed is the players.

[Mojo]

I love the claim that "double blind tests disorient the listener".

[Badly Shaved Monkey]

Woo beliefs co-exist in one of our favourite Homeopath apologists if you recall, Mojo.

Our old friend bach/bwv12 extended his smug certainty over the discerning power of the individual to 'know' what works to both homeopathy and audiophilia. I think the common theme is an inability to accept that objective reality may differ from what you perceive and want it to be. He wants sugar pills to be magic and he wants high-end audio systems to do something better than cheaper devices. Objective testing says they are not, but rather than review his assumptions he declares that it's the objective testing that is in error.

A bit like the Hitchhikers Guide episode where a court case decides that if truth is beauty then beauty is truth and that when life contravened that rule it was in contempt of the court so was confiscated from all those present.

[Aitch]

Ah, but according to one of the comments on the link, "Reviewers are trained and seasoned pros, and in the case of most audio rag editorial staff, who set the review rules... very well seasoned in all the aspects." So that's all right then. ;)

Mind you, he also goes on to say: "When these DBT people have spent over 20 years designing or building gear AND they have good hearing connected to a THINKING and WORKING brain..their answer will be different.

But in the meantime they are armchair experts- and they may always be exactly that. Sorry. " So maybe not. ;)

[sol invictus]

Audio reviewers are one step away from being paid shills for the high-end audio industry. Blind tests would ruin the whole game, because they would reveal that there are essentially no audible differences between amplifiers, DACs, CD players, etc. - and those products form what's probably a majority of the industry's business.

So it's not going to happen. At least Stereophile publishes measurements.

[jj]

Ah, but according to one of the comments on the link, "Reviewers are trained and seasoned pros, and in the case of most audio rag editorial staff, who set the review rules... very well seasoned in all the aspects." So that's all right then. ;)

Mind you, he also goes on to say: "When these DBT people have spent over 20 years designing or building gear AND they have good hearing connected to a THINKING and WORKING brain..their answer will be different.

But in the meantime they are armchair experts- and they may always be exactly that. Sorry. " So maybe not. ;)

I didn't bother to respond to that particular bit of libel. There's no point. If someone is willing to lie like the individual you cite, there isn't a lot of discussion to be had.

What the person who said that doesn't care about is that reviewers for the most part are not technical people (and those who are tend to be DBT users, not so surprisingly), and that the people he's arguing with (Ethan, Sean, Floyd, myself) have rather over a combined century of experience in the field in the testable, verifiable scientific aspects, too.

[dudalb]

Audio reviewers are one step away from being paid shills for the high-end audio industry. Blind tests would ruin the whole game, because they would reveal that there are essentially no audible differences between amplifiers, DACs, CD players, etc. - and those products form what's probably a majority of the industry's business.

So it's not going to happen. At least Stereophile publishes measurements.
,


To be fair, an awful lot of audiophiles don't need much selling to blow big bucks on the latest audio gimmick. I am not sure the blind testing would help a lot. Some Audiophiles are among the biggest suckers on earth.
Speaking of which....
Calling extremeskeptic,calling extremeskeptic.....

[BenBurch]

To be fair, an awful lot of audiophiles don't need much selling to blow big bucks on the latest audio gimmick. I am not sure the blind testing would help a lot. Some Audiophiles are among the biggest suckers on earth.
Speaking of which....
Calling extremeskeptic,calling extremeskeptic.....

What *I* want is the CHEAPEST really good system you can put together.

Then again I pinch each penny until Lincoln cries for mercy.

[dudalb]

That's what I want also.
That pretty much eliminates us from being hardcore audiophiles,since they seem to WANT to spent as much money as possible on their equipment since it gives them bragging rights.
No fool like a audiofool.

[jj]

That's what I want also.
That pretty much eliminates us from being hardcore audiophiles,since they seem to WANT to spent as much money as possible on their equipment since it gives them bragging rights.
No fool like a audiofool.

What's your speaker budget and do you have a wood shop? :)

[alfaniner]

Some of the first exposure I had to true bleevers were in some of the audio threads on this Forum.

I remember specifically they guy who thought he could prove that by placing some sort of computer chip on top of a CD player, it would improve the sound. Except on the weekend...

[Mercutio]

What's your speaker budget and do you have a wood shop? :)
Very low, and yes.

Ideas?

[jj]

Very low, and yes.

Ideas?

Yes, actually. I just built myself a very nice set of speakers. Probably a bit overbuilt for your use. I'll pm at you.

[Terry]

Oooh, speaker construction! Could you post some more information?

[jj]

Oooh, speaker construction! Could you post some more information?

See yer PM's. Kinda hard to do here without posting .pdf's and such, and I don't think it's quite in the JREF mission...

[roger]

jj,

Any advice for an enclosure for a ribbon driver? I have 2 fugly speakers that I'd love to purty up, but don't want to compromise response much. Right now the ribbons just stand on top of the enclosure, with the enclosure (holding scan-speak cone drivers) wrapped in black vinyl. I'd rather just have a tall rectangular box, with the ribbons mounted in the enclosure, not just sitting on top of it. I figure if I make the top half of the enclosure, the one holding the ribbons, entirely sealed, with just an indentation to hold the ribbon, there would be minimal acoustic impact to the empty space behind the ribbon, but what do I know (the answer: nothing).

[sol invictus]

See yer PM's. Kinda hard to do here without posting .pdf's and such, and I don't think it's quite in the JREF mission...

Actually I think a discussion of speaker designs is fully within the bounds of this forum. The participants could learn quite a bit about acoustics, which certainly falls under science and technology (and education).

Would you mind posting them?

[TriskettheKid]

I'm slightly confused.

Are we talking about reviewers of things like Grado headphones?

Or something like the guys who think Monster cables are God's gift to the audio world?

[jj]

jj,

Any advice for an enclosure for a ribbon driver? I have 2 fugly speakers that I'd love to purty up, but don't want to compromise response much. Right now the ribbons just stand on top of the enclosure, with the enclosure (holding scan-speak cone drivers) wrapped in black vinyl. I'd rather just have a tall rectangular box, with the ribbons mounted in the enclosure, not just sitting on top of it. I figure if I make the top half of the enclosure, the one holding the ribbons, entirely sealed, with just an indentation to hold the ribbon, there would be minimal acoustic impact to the empty space behind the ribbon, but what do I know (the answer: nothing).

Is the ribbon driver a dipole (open both front and back) or just open in front? That's the first thing to ask. Can you tell me (here, pm, whatever) what the actual driver is?

The answer can change rather a lot by driver.

As an aside most people seem to go with "driver sitting on top". The speakers I just finished use a ribbon, but a small single-sided one in the middle of a WMTMW array. Also uglier than you want to believe. The ones for the lab are getting the "two coats of primer and satin black" treatment. :)

jj

[jj]

I'm slightly confused.

Are we talking about reviewers of things like Grado headphones?

Or something like the guys who think Monster cables are God's gift to the audio world?

Yes. Seriously, both and more.

[TriskettheKid]

Yes. Seriously, both and more.

I'm both shocked...and not shocked.

I mean, I can't shell out big $$$ for headphones, but the reviews for the two headphones I do own were spot on. I love my SR-80s, and my HD-485s. But I'm guessing you're saying that more of this stuff is happening with the reference-quality stuff out there, like the $1000 pair of headphones and what not, right?

I've never understood the passion some have for the Monster cables, though. I've seen the reviews praising their quality. Then I've seen the OTHER reviews, in which Monster cables were compared to, say, a bent wire hanger that was used to connect equipment. People were furious over the implication that their $100+ Monster cables were no better than a $.50 wire hanger in terms of sound quality over short-ish distances of cable length.

[ponderingturtle]

See yer PM's. Kinda hard to do here without posting .pdf's and such, and I don't think it's quite in the JREF mission...

Hey it would put the E into JREF.

What sort of woodshop is required?

[ponderingturtle]

I'm both shocked...and not shocked.

I mean, I can't shell out big $$$ for headphones, but the reviews for the two headphones I do own were spot on. I love my SR-80s, and my HD-485s. But I'm guessing you're saying that more of this stuff is happening with the reference-quality stuff out there, like the $1000 pair of headphones and what not, right?

I've never understood the passion some have for the Monster cables, though. I've seen the reviews praising their quality. Then I've seen the OTHER reviews, in which Monster cables were compared to, say, a bent wire hanger that was used to connect equipment. People were furious over the implication that their $100+ Monster cables were no better than a $.50 wire hanger in terms of sound quality over short-ish distances of cable length.

Well while the wire hangers might give excelent quality it would be hard to manage them in the back of a typical set up.

[TriskettheKid]

Well while the wire hangers might give excelent quality it would be hard to manage them in the back of a typical set up.

No doubt.

But going towards DBT, it seems that even audiophiles were hit-or-miss when it came to telling whether the setup was done using a wire hanger, or the high quality Monster cable.

Honestly, I think you can easily tell in regards to some audio setups/headphones on the low-end, whereas the high end becomes more a question of branding than anything else.

[sol invictus]

But going towards DBT, it seems that even audiophiles were hit-or-miss when it came to telling whether the setup was done using a wire hanger, or the high quality Monster cable.

Honestly, I think you can easily tell in regards to some audio setups/headphones on the low-end, whereas the high end becomes more a question of branding than anything else.

If you ignore what audiophiles say, and instead pay attention to what they and others can actually demonstrate and what the science says, the situation is quite clear. Here's what matters, in order of importance:

The original performance.

The recording of that performance.

The speakers - there are large differences among speakers (and headphones), because they involve some very imperfect moving parts.

The listening room and speaker placement - different rooms and positioning have a large impact on sound quality.

The amplifier - it should be adequate to drive the speakers it's connected to at the levels you want without clipping. That's generally easy (and fairly cheap) to achieve with modern solid state electronics.

The source - the tiny differences between modern digital sources are basically irrelevant when it comes to sound quality. For vinyl the differences may be more important - but if you're listening to vinyl you're probably an audiophile and will deny all of this anyway.

The wires - totally irrelevant in any even vaguely realistic home audio scenario.

[TriskettheKid]

Actually, if there's one thing I've picked up in my very amateurish love of music (my first "high-end" pair of headphones was a set of HD-485s, followed up by my still current favorites, SR-80s), it's this:

Forget Monster cables and the wire hangers.

I want to know just how full of **** Bose is with their claims about their equipment and setups.

[jj]

Actually, if there's one thing I've picked up in my very amateurish love of music (my first "high-end" pair of headphones was a set of HD-485s, followed up by my still current favorites, SR-80s), it's this:

Forget Monster cables and the wire hangers.

I want to know just how full of **** Bose is with their claims about their equipment and setups.

I wouldn't touch that with a 10 foot pole.

[jj]

Hey it would put the E into JREF.

What sort of woodshop is required?

Well, you need to cut 50" high (give or take) MDF or plywood. So you need to be able to handle 8' sheets for ripping and crosscutting, and be able to cut both round and square holes reasonably accurately.

Other than that, any fancy joinery is up to how you want things to look.

[jj]

If you ignore what audiophiles say, and instead pay attention to what they and others can actually demonstrate and what the science says, the situation is quite clear. Here's what matters, in order of importance:

The original performance.

The recording of that performance.

The speakers - there are large differences among speakers (and headphones), because they involve some very imperfect moving parts.

The listening room and speaker placement - different rooms and positioning have a large impact on sound quality.

The amplifier - it should be adequate to drive the speakers it's connected to at the levels you want without clipping. That's generally easy (and fairly cheap) to achieve with modern solid state electronics.

The source - the tiny differences between modern digital sources are basically irrelevant when it comes to sound quality. For vinyl the differences may be more important - but if you're listening to vinyl you're probably an audiophile and will deny all of this anyway.

The wires - totally irrelevant in any even vaguely realistic home audio scenario.


This isn't a bad summary. Speakers, listening room and placement must all go together, though, not separately. It's one mess that interacts with everything.

[Mojo]

Woo beliefs co-exist in one of our favourite Homeopath apologists if you recall, Mojo.

Our old friend bach/bwv12 extended his smug certainty over the discerning power of the individual to 'know' what works to both homeopathy and audiophilia.


Actually, I didn't know that - I'd figured he was into Bach, obviously, but liking music doesn't necessarily mean being heavily into audio (if you remember Flanders & Swann... ;)).

[Aitch]

You missed out one very important factor, Sol. The state of your hearing. After a certain age (or possibly a certain number of over-loud rock concerts), frequency response diminishes, as does sensitivity. :(

[roger]

Is the ribbon driver a dipole (open both front and back) or just open in front? That's the first thing to ask. Can you tell me (here, pm, whatever) what the actual driver is?

The answer can change rather a lot by driver.

As an aside most people seem to go with "driver sitting on top". The speakers I just finished use a ribbon, but a small single-sided one in the middle of a WMTMW array. Also uglier than you want to believe. The ones for the lab are getting the "two coats of primer and satin black" treatment. :)

jj
They are Newform Research R30s, which are just open in the front.

This is not really a big deal, it's more something I'm mulling over than I'm all fired up to do.

[Ivor the Engineer]

I've never understood why speakers for home use have any more than two drivers (woofer and tweeter) in them.

Spend the money saved on drivers on an active (ideally DSP-based) crossover, motional feedback for the woofer, separate power amplifiers for the drivers and making a smaller, more rigid enclosure.

[jj]

Actually, I didn't know that - I'd figured he was into Bach, obviously, but liking music doesn't necessarily mean being heavily into audio (if you remember Flanders & Swann... ;)).

Have some Madeira, M'Dear!

[jj]

I've never understood why speakers for home use have any more than two drivers (woofer and tweeter) in them.

Spend the money saved on drivers on an active (ideally DSP-based) crossover, motional feedback for the woofer, separate power amplifiers for the drivers and making a smaller, more rigid enclosure.

Well, let me see:

Radiation Pattern Control
Motor (voice coil) distortion
Dopplar distortion
Air motion noise
Crossover point in the vocal range

This is why the ones I just built have 5 drivers. Then again, I am particularly annoyed by almost any perceptable form of distortion.

Just for kicks, those are all very telling. But if you want to go cheap, 2-way is certainly the way to go, the chance of them getting the crossover right in a 3-way is negligible, in my experience.

[jj]

They are Newform Research R30s, which are just open in the front.

This is not really a big deal, it's more something I'm mulling over than I'm all fired up to do.

I'm not sure I'd do much more than maybe put a couple of supports at the back/side, say dowels, to keep the whole thing stable.

If you do a wider front, then we're going to have to deal with the radiation pattern of the driver at different frequencies, edge diffraction, etc. Not sure it's worth it.

[Ivor the Engineer]

Well, let me see:

Radiation Pattern Control

In a house with windows, carpets and furniture?

Motor (voice coil) distortion

Did I say motional feedback?

Dopplar distortion

Did I say DSP-based active crossover?

Air motion noise

What does that sound like?

Crossover point in the vocal range

<snip>

Use linear phase (FIR) filter. Mount drivers less than a wavelength apart at the low (~1.5kHz) crossover frequency. Compensate for driver cones being different distances from the ears of the listener, typically by delaying the signal to the tweeter by a fixed amount.

[jj]

In a house with windows, carpets and furniture?


Definately. It makes it even more necessary to have good pattern control so you don't bounce off those windows, walls, and furniture too early in the acoustic path.


Did I say motional feedback?


Ok for low levels of bass, useless for high levels (except with very pricey, extremely smart processing) or frequencies above 100Hz or so, at least with cheap drivers. (remember, you said "cheap" so no titanium cones)


Did I say DSP-based active crossover?


DSP crossovers, of which I've designed quite a few, can do exactly zip for doppler distortion. Zero, in fact. If the LF radiator is going up into the khz range, and you have any significant bass, you're in trouble.

What's more, the driver nonlinearities there that change the GAIN of the motor with excursion make high frequency distortions very common, and motional feedback does NOTHING for that.


What does that sound like?


"Port noise". Yes, you can get a lot of bass out of a small box. In order to do so, you have to move a lot of air. Remember that you have to move 4 times as much air to get the same SPL at half the frequency, please.

And when you use that small box and high-q designs, you can easily get port noise, etc. In fact, it's epidemic in small boxes.


Use linear phase (FIR) filter. Mount drivers less than a wavelength apart at the low (~1.5kHz) crossover frequency. Compensate for driver cones being different distances from the ears of the listener, typically by delaying the signal to the tweeter by a fixed amount.


Using an FIR doesn't help you at all. You still have to compensate for the phase response of the driver, and if you're in the mid-vocal range with a woofer, that is going to vary wildly with direction, because you're also dealing with a whole bunch of cone modes, being way above the first cone resonance frequency, again, for cheap drivers, not titanium cones. Adding delay and such is penny-ante work, anyone doing a decent digital crossover had better have done it already.

Now, using FIR's has another set of problems. What do you do about the pre-ringing you get in the constant-delay FIR? Or do you use a non-linear-phase FIR? Or do you use an IIR with allpass elements? :) :) It's not as simple as you imagine. You can, however, get constant phase from a good digital crossover, but you can from the right kind of passive crossover, too, with more parts.

Um, I've been designing filters since at least 1978....

[sol invictus]

What do you think of open baffle designs like the Linkwitz Orions, jj?

And yes, I agree re: room and speaker interactions.

[Gord_in_Toronto]

I wouldn't touch that with a 10 foot pole.

Consumer Reports tested the Bose "Wave Radio" (or whatever it is called) a couple of years ago. ISTR that they said, essentially, it was not worth the money and the were better radios at half the price.

I tend to go with CR for most things -- audio included. They always do blind testing.

Oh. Look from Wiki:

In 1981 the Bose Corporation sued Consumer Reports (CR) magazine for libel. CR reported in a review that the sound from the system that they reviewed "tended to wander about the room". The District Court found that CR "had published the false statement with knowledge that it was false or with reckless disregard of its truth or falsity". The Court of Appeals reversed the trial court's ruling, and the United States Supreme Court affirmed in Bose Corp. v. Consumers Union of United States, Inc., finding that CR's statement was made without actual malice, which was the standard in cases where the First Amendment was involved; and therefore was not libelous. ;)

[jj]

What do you think of open baffle designs like the Linkwitz Orions, jj?

And yes, I agree re: room and speaker interactions.

It depends on what the polar pattern comes out to for any open-baffle design, and even more on where you are going to put them.

In general, they are fine when you can put them somewhere good, but can be awful when in the wrong room.

I find a carefully designed, power-flat, direct-flat design (well, mostly flat, of course) front radiator that has a controled vertical dispersion easier to place in an average room.

But in the right room ... Well if I had that room I'd design different speakers, and we all know Seigfried is a very smart dude :)

[Ivor the Engineer]

Definately. It makes it even more necessary to have good pattern control so you don't bounce off those windows, walls, and furniture too early in the acoustic path.

Right... Good luck with that.

Ok for low levels of bass, useless for high levels (except with very pricey, extremely smart processing) or frequencies above 100Hz or so, at least with cheap drivers. (remember, you said "cheap" so no titanium cones)

Why? (And why is DSP expensive? Once the algorithm has been coded the cost is zero).

DSP crossovers, of which I've designed quite a few, can do exactly zip for doppler distortion. Zero, in fact. If the LF radiator is going up into the khz range, and you have any significant bass, you're in trouble.

Doppler distortion is a bit of a misnomer. What is basically happening is the large motion of the cone at low frequencies is phase modulating higher frequencies. For reasonable cone excursions in a home system (+-3mm) this is not going to cause a huge frequency shift and I doubt it's audible under typical listening conditions.

What's more, the driver nonlinearities there that change the GAIN of the motor with excursion make high frequency distortions very common, and motional feedback does NOTHING for that.

:confused:

Applying negative feedback to a non-linear actuator does nothing to improve its linearity?

"Port noise". Yes, you can get a lot of bass out of a small box. In order to do so, you have to move a lot of air. Remember that you have to move 4 times as much air to get the same SPL at half the frequency, please.

And when you use that small box and high-q designs, you can easily get port noise, etc. In fact, it's epidemic in small boxes.

No ports. Sealed box.

Using an FIR doesn't help you at all. You still have to compensate for the phase response of the driver, and if you're in the mid-vocal range with a woofer, that is going to vary wildly with direction, because you're also dealing with a whole bunch of cone modes, being way above the first cone resonance frequency, again, for cheap drivers, not titanium cones. Adding delay and such is penny-ante work, anyone doing a decent digital crossover had better have done it already.

The cone is acting as a piston up to the crossover frequency.

Now, using FIR's has another set of problems. What do you do about the pre-ringing you get in the constant-delay FIR? Or do you use a non-linear-phase FIR? Or do you use an IIR with allpass elements? :) :) It's not as simple as you imagine. You can, however, get constant phase from a good digital crossover, but you can from the right kind of passive crossover, too, with more parts.

Do you have a DBT which demonstrates that people can actually hear the pre-ringing of a linear phase FIR filter?

Um, I've been designing filters since at least 1978....

Argument from antiquity.:)

[jj]

Right... Good luck with that.


Thanks but I don't need luck, it works fine when you do it right.


Why? (And why is DSP expensive? Once the algorithm has been coded the cost is zero).


Um, it's not the DSP, although the codecs, etc, done in a clean fashion are not cheap, they aren't expensive. The problem is in the cone breakup in the driver. You WILL NOT get a two-way operating completely inside cone breakup unless you spend enough on a wide range ribbon tweeter that you might as well make something more complicated. The problem with all forms of feedback is first that anything sensed at the voice coil does not represent the actual output above mid-bass frequencies, and second that if you use acoustic pickup you have a nasty e^-st term and you are NOT going to be able, especially in the presence of nonlinearities, to get a stable system. There's lots of literature on this.


Doppler distortion is a bit of a misnomer. What is basically happening is the large motion of the cone at low frequencies is phase modulating higher frequencies. For reasonable cone excursions in a home system (+-3mm) this is not going to cause a huge frequency shift and I doubt it's audible under typical listening conditions.


What Xmax do you need to get significant phase distortion at 3 kHz? Less than you expect. Yes, I'm sure. Do the math.



:confused:

Applying negative feedback to a non-linear actuator does nothing to improve its linearity?


Feedback only works if you have a meaningful error signal. You don't.


No ports. Sealed box.


Small speaker, no ports, no bass. Large speaker, 100x the problems with cone breakup, and at much lower frequencies.


The cone is acting as a piston up to the crossover frequency.


Sorry. No. 'tisint in most any 2-way.


Do you have a DBT which demonstrates that people can actually hear the pre-ringing of a linear phase FIR filter?


Not any more. Did have one that was, well, annoyingly clear, doing a crossover between bass and mid at 300Hz. Had to go to minimum-phase, some phase equalization via allpass after the minimum phase filter, and a subtractive design. Worked like a charm.


Argument from antiquity.:)

Argument from EXPERIENCE.

I do agree that for low priced speakers, you are 99% likely to be better off with a 2-way. But that's not what we're talking about.

[Ivor the Engineer]

What is the speed of sound in a typical (say paper) speaker cone?

[jj]

What is the speed of sound in a typical (say paper) speaker cone?

Depends quite a lot on the formulation, I fear, as well as humidity, accuracy of manufacture, etc. One answer will not suffice. Sorry.

Also, what mode of propagation? Compression? Traverse? Consider what happens when you have both compression and traverse modes going, and you have small irregularities in the material. I dare you to try to model that :p

(and "small irregularities" goes with "expensive drivers" too)

[alfaniner]

What is the speed of sound in a typical (say paper) speaker cone?

Is that an African or a European speaker cone?

[luchog]

Honestly, I think you can easily tell in regards to some audio setups/headphones on the low-end, whereas the high end becomes more a question of branding than anything else.

When I buy audio-visual gear, I go for moderately high-end stuff, and just wait for a good sale. I also tend to stick with certain brands. Not because I think there's a substantial difference in the quality between high-end and moderately-prices gear, or between brands; but because there is definitely a difference in reliability and quality of service. :D

[jj]

Well, that's kinda funny now. Some "budda" guy showed up again, and tried some of the most lame extractions from context, misquotes, straw men, and so on I've seen since arguing here with some of the more insane Obama-phobes.

It's much like arguing like a creationist, frankly. Why do they have to infest my own field, for (*&(* sake.

[Badly Shaved Monkey]

Actually, I didn't know that - I'd figured he was into Bach, obviously, but liking music doesn't necessarily mean being heavily into audio (if you remember Flanders & Swann... ;)).

Indeed, and now you must apologise for inducing me to wade once more into the self-satisfied grandiloquent posturing of the person I have found the most trying in all my time interacting with the homs.

I'm mobile again and can't cut and paste links, but if you put otherhealth + oreganon [sic] into Google it'll take you to a thread that finds bach/bwv11 (I think he varied which bwv number he used) in full flow around pages 15 and 16. Interestingly, he also alludes to the disorientation the poor audiophile suffers when forced to listen under blinded conditions, which I think mostly means he can't see the price tag or hear the sound of his exasperated wife leaving him to spend more time with his hand-blown vacuum tubes.

[Mojo]

Interestingly, he also alludes to the disorientation the poor audiophile suffers when forced to listen under blinded conditions, which I think mostly means he can't see the price tag or hear the sound of his exasperated wife leaving him to spend more time with his hand-blown vacuum tubes.


I assume it's similar to the disorientation Kate Chatfield (http://www.publications.parliament.uk/pa/ld200607/ldselect/ldsctech/166/7022105.htm) might feel if unable to see the label. ;)

[Badly Shaved Monkey]

I assume it's similar to the disorientation Kate Chatfield (http://www.publications.parliament.uk/pa/ld200607/ldselect/ldsctech/166/7022105.htm) might feel if unable to see the label. ;)

Is it their certainty or their stupidity that is the more depressing? Though, of course, they are synergistic and the sum is definitely greater than the parts.

Technical question- how did those foot notes get inserted? Did Chatfield get to append what she wanted to say but forgot to say, or did the minute-taker slip up and not write down her deep insights properly in the first place?

Sorry all, we risk derailing the thread, though we are still talking about blinding here.

[jj]

It's all the same thing, people who trust sighted perception without any backup evidence.

The song really is the same, isn't it? Homeopaths, creationists, far-out audiophiles...

[Badly Shaved Monkey]

I think the unbridgeable gulf fundamentally lies between those of us who are happy, actually find it exciting, when objective evidence confounds our expectations, and those who believe they really 'know' the Truth, only accept evidence that confirms their prejudice and will jump through limitless hoops to evade any need to reconsider their prior assumptions. Which is why the accusation that we sceptics are closed-minded is particularly ill-founded.

[Ivor the Engineer]

I think the unbridgeable gulf fundamentally lies between those of us who are happy, actually find it exciting, when objective evidence confounds our expectations, and those who believe they really 'know' the Truth, only accept evidence that confirms their prejudice and will jump through limitless hoops to evade any need to reconsider their prior assumptions. Which is why the accusation that we sceptics are closed-minded is particularly ill-founded.

Sceptics enjoy seeing photos of their partner cheating on them?:)

[Mojo]

Ah, the triumph of hope over experience...

[Badly Shaved Monkey]

Sceptics enjoy seeing photos of their partner cheating on them?:)



I thought your wife looked good in those photos, but I found the gimp mask a bit uncomfortable.

[Aitch]

You probably had it on back-to-front. Again. ;)

[technoextreme]

and second that if you use acoustic pickup you have a nasty e^-st term and you are NOT going to be able, especially in the presence of nonlinearities, to get a stable system. There's lots of literature on this.

I love engineers. Instead of saying time delay they say e^-st . :p

[Badly Shaved Monkey]

You probably had it on back-to-front. Again. ;)

Talk about a blinded trial!

[portlandatheist]

I love the claim that "double blind tests disorient the listener".

That is freakin' hilarious!

[jj]

Check out Jan Vigne's most recent (as of now) response to me. My goodness.

[Paulhoff]

I would like to sidebar this thread.

My friend and his wife came down here from Pa. for a visit down here in Florida just a few days ago. My friend is into audio and I have mentioned him in other posts. He is also into what we call woo-woo on wires and how digital sound works among other woos, but these that the major ones now.

Last year when they came down to visit, he changed my speaker wire and my digital optical cable (Toslink) for my DVD player to some other speaker wire that I don’t care to remember and coax cable. After doing this he said that they system now sounded better. And when we went from my 5 disk player to the more expensive DVD player it again sounded better to him yet. My son and I heard NOTHING new in the sound. No DBT done, and I didn’t care, I have done this stuff with him for about 25 years now and have gotten tired of it all. His explanation for what he did was that digital is susceptible to RF on the speaker wires and that Toslink somehow loses something (?) in the digital information, that somehow digital was dainty (not his words, but close to what he was saying).

This year, he did nothing to my system, nothing, I was surprise, I thought maybe he have learned something, but no.

Ok some history, his old speaker drivers surrounds (foam rubber) have been giving-out. I myself liked the English speakers, and they are expensive ones, a few thousand for the pair. He has been trying for some time now, over a year, to fix or replace the drivers (JJ has tired to help in finding new drivers). The new speaker drivers are very expensive, so he bought new used speakers, made by another English company. At first he and his wife didn’t like them (nothing new for him) and he tried to keep the older speakers running as long has he could, and finally he gave up and started to play the new ones. Then he got on AudiogoN, and found out the speakers needed a long break-in period, SURE. He wrote to the company and they said that they needed 500 hours to break in, SURE. Now the love the speakers, and it seems that they sound a lot like mine, PSB T-45, that have in the booklet that comes with them, NO BREAKIN NEEDED. Paul Barton designer etc of the speakers believes in Brain Break-in, which is why my friend even likes my speakers more now.

Now the little funny part, I was asked by him at least 3 or more times in the week that he was here if I did something to the system, I told him no, it is the same has last year when he left. He asked my son and wife too. My wife saw him looking behind my system at least two times looking for changes. He also asked if I dedicated and power line (woo) to the system.

So I told him the only thing that changed was his system and now him being used to a new speaker sound, end of story.

Paul

:) :) :)

P.S. now since my speakers have a better bottom end, he is looking into a subwoofer, geezz.

[soylent]

I love the claim that "double blind tests disorient the listener".

I believe the proper term for the disorientation they experience is cognitive dissonance.

[jj]

P.S. now since my speakers have a better bottom end, he is looking into a subwoofer, geezz.

Oy vey.

Anyhow, this Saturday, if you want, I can show you how to grab some woofer and subwoofer design programs off the net, and get some driver specs and build yourself an even better subwoofer.

It is TRIVIALLY EASY nowadays.

And then see what he does (evil cackle).

ETA: Oh, heck with it. I'll put the design in the next article.

There's a story here. When highenders look at my equipment, their first reaction is "what cheap*** stuff", where the three asterisks refer to either the human buttocks or a donkey.

So, next article, the cheap*** subwoofer :)

[jj]

Tang Band W8-1747 8" Aluminum Cone Subwoofer
in a 15.5 liter box will have a 3dB down point at 50 Hz, but useful output at 30 Hz (100dB SPL). Sealed box. Standard electronic EQ will bring out the entire range down to under 30Hz under most user conditions. Not quite the best performer, trivial (to say the least) to build and use.

Dayton RSS210HF-4 8" Reference HF Subwoofer 4 Ohm

in a box with 11" x 15" x 28.5" interior dimensions, and a 4" PVC pipe 24.4" long as a port will give you a -3dB point of 20Hz and 105dB max output down to 20Hz.

In either box, use a half sheet of king sized "high loft" poly quilt batting lining the insides and stuffed into the box as damping material.

harder to build, even easier to use (it's flat effectivcely in the 20Hz to 90Hz range you should be using a sub with, maximum, I'd prefer 20 to 40Hz, but that's not the case for many speakers).

So there, paul, the cheap... subwoofers, take your pick. :) :) :)

[Paulhoff]

I hope to called you tonight to tell you I have the emails you sent me with the picture of the speaker on a stick..........

I will bring it with me tomorrow.

Paul

:) :) :)

[jj]

I hope to called you tonight to tell you I have the emails you sent me with the picture of the speaker on a stick..........

I will bring with me tomorrow.

Paul

:) :) :)

Roger that.

As an aside, the subwoofers I described above would match very well to the dayton 240 watt subwoofer amps, the first one to the "boost" amp, which will flatten it very, very nicely (the amp has a boost that very nearly removes the droop in the sub down to 30Hz) and the non-boost one for the second, resulting in a very good "thud", indeed, I suspect. :)

[roger]

On the Dayton design, I assume you mean for the speaker to the on the 11x15 face, correct? The prebuilt Dayton subs seem to have the port in the back, opposite the speaker, based on the pictures on PartsExpress. Or is this intended to be a down-firing sub?

[jj]

On the Dayton design, I assume you mean for the speaker to the on the 11x15 face, correct? The prebuilt Dayton subs seem to have the port in the back, opposite the speaker, based on the pictures on PartsExpress. Or is this intended to be a down-firing sub?

Woofer on one side, port on the far side, front is a long side.

This woofer is not capable of downfiring well.

But it does just fine in standard position. You should roll the enclosure 180 degrees every so often and leave it either way for about the same length of time.

[Paulhoff]

You should roll the enclosure 180 degrees every so often and leave it either way for about the same length of time.
Does the surround etc distort?

Paul

:) :) :)

[jj]

Does the surround etc distort?

Paul

:) :) :)


Some will droop over time, some will not. Rather be sure.

[jj]

Interesting. Geoff Kait, whose name matches that of the seller of the "Intellegent Chip" that failed to win the Prize a while ago, has showed up to disparage me.

I'm amazed, let me tell you, just amazed. He even invokes Randi as a reference for his disparagement.

Gotta love the guy.

Or something.


http://forum.stereophile.com/forum/showthreaded.php?Cat=0&Number=65946&page=0&vc=1

If it's the same Kait, I guess he's still bitter over the results of the test of the "intellegent chip".

[Paulhoff]

Well, I still haven't got the magic email to let me on the so-called Forum.

Paul

:) :) :)

They most likely know me :D

[jj]

Well, I still haven't got the magic email to let me on the so-called Forum.

Paul

:) :) :)

They most likely know me :D

Odd, they let me on, and they most certainly know me.

You have to watch out, some email services tend to spam-filter the "registration email" you get :(

[Paulhoff]

Good thing anyway that I'm not on that forum.

http://forum.stereophile.com/forum/showflat.php?Cat=0&Number=64194&an=0&page=0#Post64194


Paul

:) :) :)

[beachnut]

Well, let me see:

Radiation Pattern Control
Motor (voice coil) distortion
Dopplar distortion
Air motion noise
Crossover point in the vocal range

This is why the ones I just built have 5 drivers. Then again, I am particularly annoyed by almost any perceptable form of distortion.

Just for kicks, those are all very telling. But if you want to go cheap, 2-way is certainly the way to go, the chance of them getting the crossover right in a 3-way is negligible, in my experience.

http://i286.photobucket.com/albums/ll116/tjkb/IMG_1057b.jpg
5'x17''x21'',6 chamber box at 1 inch, to 2.75 inches thick, 4 way, electronic crossover, quad amp, center channel made from the kids old bunk bed. The tweeter the same as a 25k speaker; 35 bucks. I need to do a DBT to see if I did better than the center from infiity I moved out.

The best part of building is getting help from your babysitting stuckee -

http://i286.photobucket.com/albums/ll116/tjkb/keynansubwoofer2.jpg

http://i286.photobucket.com/albums/ll116/tjkb/sub1a.jpg
And it worked even with cookie crumbs.

http://i286.photobucket.com/albums/ll116/tjkb/terroristspeaker.jpgIt is amazing how much you can do when you babysit.

Is your 5 driver 3 way? Do you try to keep 70 to 1000 clean of crossover?

[jj]

Is your 5 driver 3 way? Do you try to keep 70 to 1000 clean of crossover?

3-way, passive crossover, 700 and 5600 Hz crossovers.

You do realize that the 500 to 2000 Hz range is where the two detection mechanisms on the basliar membrane conflict, and you have surprisingly less phase sensitivity?

I've got a photo of one, but I must edit my offspring out of it...

ETA: done
http://forums.randi.org/picture.php?albumid=184&pictureid=929

[beachnut]

3-way, passive crossover, 700 and 5600 Hz crossovers.

You do realize that the 500 to 2000 Hz range is where the two detection mechanisms on the basliar membrane conflict, and you have surprisingly less phase sensitivity?

Now I do. Fundamentals of Hearing (http://www.aes.org/sections/pnw/ppt/jj/jj_aes04_ts1.ppt) Is that your presentation?

[jj]

Now I do. Fundamentals of Hearing (http://www.aes.org/sections/pnw/ppt/jj/jj_aes04_ts1.ppt) Is that your presentation?

Yeah, it is.

The issues I see in the vocal range are in the 3rd formant, above 2kHz. You can get some interesting sounds if the phase change due to crossover behavior is too fast.

You can get troubles in the 500-2000 range, too, but the change in phase shift per critical band/ERB has to be more. (i.e. group delay is the issue)

[sol invictus]

The tweeter the same as a 25k speaker; 35 bucks.

The tweeter in the speaker in the bottom photo didn't cost $35... more like $200, no?

[beachnut]

The tweeter in the speaker in the bottom photo didn't cost $35... more like $200, no?
The center channel was 35 bucks, or 45. The 7 driver speaker.

The tweeter in the lower was 180 or 200.

I found it interesting when I researched the cheap tweeter it was used in a giant 25k speaker.

You are right

[sol invictus]

The center channel was 35 bucks, or 45. The 7 driver speaker.

The tweeter in the lower was 180 or 200.

I found it interesting when I researched the cheap tweeter it was used in a giant 25k speaker.

You are right

OK, too bad - I thought you might have found a source for cheap Excel Milleniums...

[Paulhoff]

I found it interesting when I researched the cheap tweeter it was used in a giant 25k speaker.
25K, geezzz, that is way to much. :(

I hope to build JJ speakers in a few months, I hope to order the drivers and have my brother-in-law build or at least cut the boards for them.

Paul

:) :) :)

[beachnut]

3-way, passive crossover, 700 and 5600 Hz crossovers.

You do realize that the 500 to 2000 Hz range is where the two detection mechanisms on the basliar membrane conflict, and you have surprisingly less phase sensitivity?

I've got a photo of one, but I must edit my offspring out of it...

ETA: done
http://forums.randi.org/picture.php?albumid=184&pictureid=929
What are the drivers?

[Paulhoff]

"What are the drivers?"

Tweeter: http://www.parts-express.com/pe/showdetl.cfm?Partnumber=277-112
Midranges: http://www.parts-express.com/pe/showdetl.cfm?Partnumber=264-848
Woof!: http://www.parts-express.com/pe/showdetl.cfm?Partnumber=290-322

xover: http://www.parts-express.com/pe/showdetl.cfm?Partnumber=260-156
midranges in parallel with 4 ohm resistor in series with the parallel set.
tweeter in series with 2 ohm resistor, and then 8 ohm l-pad to crossover.

Port length is 2" standard PVC 6 3/8" heavy (i.e. between 6 3/8 and 6 1/2)

Paul

:) :) :)

[jj]

Tweeter: http://www.parts-express.com/pe/showdetl.cfm?Partnumber=277-112
Midranges: http://www.parts-express.com/pe/showdetl.cfm?Partnumber=264-848
Woof!: http://www.parts-express.com/pe/showdetl.cfm?Partnumber=290-322

xover: http://www.parts-express.com/pe/showdetl.cfm?Partnumber=260-156
midranges in parallel with 4 ohm resistor in series with the parallel set.
tweeter in series with 2 ohm resistor, and then 8 ohm l-pad to crossover.

Port length is 2" standard PVC 6 3/8" heavy (i.e. between 6 3/8 and 6 1/2)

Paul

:) :) :)


Maybe when we get the rather cryptic drawing Paul has of the box design cleaned up, he can also post that. That would be helpful.

[roger]

Woofer on one side, port on the far side, front is a long side.

This woofer is not capable of downfiring well.

But it does just fine in standard position. You should roll the enclosure 180 degrees every so often and leave it either way for about the same length of time.

like this?

[Paulhoff]

http://www.lessloss.com/dynamic-filtering-power-cable-original-p-180.html?gclid=CI6tjL2PkpoCFQKenAodkR1JRg

Just so unreal, miles and miles of wire corrected by a few magic feet of wire.

Paul

:) :) :)

[jj]

like this?

More or less. I'd keep the port along one wall of the box and glue it to the side of the box so it doesn't get loose or rattle.

[Paulhoff]

Well, I'm trying to get on that rag of a forum again.

Paul

:) :) :)

[zooterkin]

Maybe when we get the rather cryptic drawing Paul has of the box design cleaned up, he can also post that. That would be helpful.

The one in his avatar?

:)

[tsig]

http://www.lessloss.com/dynamic-filtering-power-cable-original-p-180.html?gclid=CI6tjL2PkpoCFQKenAodkR1JRg

Just so unreal, miles and miles of wire corrected by a few magic feet of wire.

Paul

:) :) :)

The poor electrons will be so dizzy and tired when they get to the power supply I do not see how they can give their best performance. Probably will need some boost capacitors and diode directors to whip them into top shape and give you the best sound they are capable of.

bc's increase peak performance---$200.00

dd's apply power where needed---$300.00(specify + or -)

stupidity--priceless

[Paulhoff]

I have a good friend who believes it, because he hears it, he does no DBTing.

Anytime I tried a DBT on him, he fails. His ears are tired, to much pressure on him, etc.

Paul

:) :) :)


The sound people notice:


Quiet background.
High resolution without listening fatigue.
Accumulative effect impressive.
Neutral tembre.
Natural dynamics.
Relaxed listening experience


Give me a break

[TriskettheKid]

So, back to a question I was thinking of earlier:

Are Grado's as good as I think they are? Or have I deluded myself based on other's reviews into thinking that the sound I'm hearing is not as good as another sound that is better?

Not the high-end Grado's, either. Their SR-80 model.

ETA:

I guess the question is, just how do I tell?

I mean, the only higher-quality headphones I have are an older pair of HD-485's and the SR-80's. Both are amazing headphones (with low enough resistance to be used on a portable player, like my iPhone), and deliver great sound without the need of a portable amp. However, high-end sounds in the HD-485's sound tinny compared to the SR-80's.

In that example, is that a true difference, or am I imagining it, or what? How would I know?

[sol invictus]

In that example, is that a true difference, or am I imagining it, or what? How would I know?

Try playing a sweep tone through them (make sure to start off at low volume, or you could hurt your ears/phones). Does the volume sound constant as it sweeps, or do you hear volume variations at different frequencies? That's a rough measure of the frequency response.

[Ivor the Engineer]

So, back to a question I was thinking of earlier:

Are Grado's as good as I think they are? Or have I deluded myself based on other's reviews into thinking that the sound I'm hearing is not as good as another sound that is better?

Not the high-end Grado's, either. Their SR-80 model.

ETA:

I guess the question is, just how do I tell?

I mean, the only higher-quality headphones I have are an older pair of HD-485's and the SR-80's. Both are amazing headphones (with low enough resistance to be used on a portable player, like my iPhone), and deliver great sound without the need of a portable amp. However, high-end sounds in the HD-485's sound tinny compared to the SR-80's.

In that example, is that a true difference, or am I imagining it, or what? How would I know?

You could compare objective measurements such as frequency response, distortion, etc., but if both sets of headphones are roughly the same on these measurements then which pair is "better" is purely subjective. One might as well ask if 75% cocoa chocolate is better than 85% cocoa chocolate.

[jj]

The one in his avatar?

:)

Well, yeah, how do you think we get a 6 cubic foot space inside of a 1x1x1 foot enclosure?

[TriskettheKid]

You could compare objective measurements such as frequency response, distortion, etc., but if both sets of headphones are roughly the same on these measurements then which pair is "better" is purely subjective. One might as well ask if 75% cocoa chocolate is better than 85% cocoa chocolate.

Well, I figured.

I'm sure that, since the HD-485s are a bit older than the SR-80s, they've been burned in better, have had more wear, etc.

So actual design doesn't matter much? I mean, suppose two sets of headphones have the same impedance, response, etc.

However, one set has 2 drivers per earcup and the other has 4. Does it really matter? Can their metrics match up, but there still be a distinctive difference in sound output?

[jj]

Well, I figured.

I'm sure that, since the HD-485s are a bit older than the SR-80s, they've been burned in better, have had more wear, etc.

So actual design doesn't matter much? I mean, suppose two sets of headphones have the same impedance, response, etc.

However, one set has 2 drivers per earcup and the other has 4. Does it really matter? Can their metrics match up, but there still be a distinctive difference in sound output?

Um, the general idea is that "burn in" doesn't matter for most acoustic transducers at all, and barely if at all for any kind of electronic equipment in the modern world. It's not like an engine where there are bearings and compression rings.

[alfaniner]

What's the best sound bite for testing speakers? My vote would be the THX zoom crescendo -- it always gives me that old Maxell tape poster feeling.

[jj]

What's the best sound bite for testing speakers? My vote would be the THX zoom crescendo -- it always gives me that old Maxell tape poster feeling.

There is no one "best sound bite".

You want to use at least

1) Something with lots of treble that will expose HF nonsense. For instance, Cowboy Junkies "Trinity Sessions" "Blue Moon"
2) Something with lots of percussion. For instance Ry Cooder, "Jazz", "We Shall Be Happy" and Great Big Sea, Track "General Taylor"
3) Something LOUD, for instance the Telarc St. Seans Symphony, last movement.
4) Something with lots of bass, for instance: Canadian Brass, Passacaglia and Fugue in (I forget, is it Gm?)
5) Male Voices: For instance, "Beautiful Rain" by Ladysmith Black Mambazo

Also, something with your favorite instrument(s) that you know and like.

Some specific and special test tracks:

Lazy, by Deep Purple, from Machine Head. About 30 seconds or so into the track, the ride cymbal will start up smack dab in the middle of the soundstage. See if it stays there. If it doesn't, you've got IM or dopplar distortion going on.

Michael Murray, at the organ of St. John the Divine, (first CD issued) - First two tracks. Just listen through and see if anything happens you don't like, but this will check for bass capacity, treble capacity, and for bunps in the bass response.

Other tracks I use: Emmylou Harris, from "Sally Rose", track "Diamond in my Crown". Listen to the drums.

Telarc recording of Berlioz Requiem, track 2, Dies Irae. Oh, yeah, Dies is Irae in that one. Listen for any kind of distortion on the crescendos, shifting images, etc, and not handling that (*&*( bass drum. That thing sounds like it's about 8' in diameter, although I know it's not.

4.2.Five - Time Machine, "Under the Boardwalk". This can be tough on midrange crossover mistakes. It will also let you konw about midrange matching between speakers if the singers start to move around per note.

Old Home Place by J.D. Crowe and the new South (Or is it Bluegrass Album Band). Can cause treble peaks to stand out like a flashlight in a cave.

[Paulhoff]

OK, you have broke my arm, I order off Cowboy Junkies from the library.

Black eyed man

Best of Cowboy Junkies

Well, that is what they have.........................

Paul

:) :) :)


geezzzzzzzzz

[Paulhoff]

Pale sun crescent moon

Miles from our home

No Trinity Sessions

YET,

I'll get on them

Paul

:) :) :)

[jj]

Well, you'd enjoy the latest there, where I put up a thread explaining why SET's (that's Single-Ended-Triodes) might sound better to some.

The SET enthusiasts showed up to revile me for explaining why their preferred boxes work, apparently.

[sol invictus]

Well, you'd enjoy the latest there, where I put up a thread explaining why SET's (that's Single-Ended-Triodes) might sound better to some.

The SET enthusiasts showed up to revile me for explaining why their preferred boxes work, apparently.

Ever posted on Audio Asylum? They make those wingnuts on the stereophile forums look polite and rational. Of course they'd probably ban you in no time over there.

Out of curiosity, do you own any tube amps? I'm tempted to buy one just to see whether it really makes such a difference. But my theory has always been that 90% of tube amps, while easily distinguishable using distortion measurements, have too low distortion (at least at moderate volume settings, not near clipping) to be distinguishable by ear from SS amps.

It sounds like you don't agree, given your post over there.... are there DBTs showing listeners being able to distinguish, or data on perceptual thresholds that indicates the difference should be audible? I always remember John Atkinson's failure (http://www.stereophile.com/features/113/) to distinguish between three amps with supposedly wildly varying tone.

[Paulhoff]

stereophile forums
I have tired two times to get on that forum, they have not let me in. THEY MUST KNOW ME, and know I don't buy into their BS.

Paul

:) :) :)

[jj]

Ever posted on Audio Asylum? They make those wingnuts on the stereophile forums look polite and rational. Of course they'd probably ban you in no time over there.

Out of curiosity, do you own any tube amps? I'm tempted to buy one just to see whether it really makes such a difference. But my theory has always been that 90% of tube amps, while easily distinguishable using distortion measurements, have too low distortion (at least at moderate volume settings, not near clipping) to be distinguishable by ear from SS amps.

It sounds like you don't agree, given your post over there.... are there DBTs showing listeners being able to distinguish, or data on perceptual thresholds that indicates the difference should be audible? I always remember John Atkinson's failure (http://www.stereophile.com/features/113/) to distinguish between three amps with supposedly wildly varying tone.

I was on the audio asylum from day one until a few years ago, when I got tired of mkuller and todd krieger following me around and arguing about stupid stuff like the sampling theorem, etc, at every chance.

Mike Kuller took to simple vilification at every opportunity, and Stephaen took this as an opportunity to get rid of both of us. I see Kuller is back, though.

[jj]

Tweeter: http://www.parts-express.com/pe/showdetl.cfm?Partnumber=277-112
Midranges: http://www.parts-express.com/pe/showdetl.cfm?Partnumber=264-848
Woof!: http://www.parts-express.com/pe/showdetl.cfm?Partnumber=290-322

xover: http://www.parts-express.com/pe/showdetl.cfm?Partnumber=260-156
midranges in parallel with 4 ohm resistor in series with the parallel set.
tweeter in series with 2 ohm resistor, and then 8 ohm l-pad to crossover.

Port length is 2" standard PVC 6 3/8" heavy (i.e. between 6 3/8 and 6 1/2)

Paul

:) :) :)


Oh, and the 2 4-ohm woofers in series, please.

[jj]

It sounds like you don't agree, given your post over there.... are there DBTs showing listeners being able to distinguish, or data on perceptual thresholds that indicates the difference should be audible? I always remember John Atkinson's failure (http://www.stereophile.com/features/113/) to distinguish between three amps with supposedly wildly varying tone.

SET amps are special tube amps, and have a lot more distortion than normal feedback designs...

BUT they have low-order distortions, and their distortion starts much earlier in the power curve and grows a lot more slowly.

So, my comments apply to SET's. They do not apply to a big tube amp with 8x 6L6GC and an output transformer the size of Youngstown... With a good design on such a push-pull device you will see little distortion until you overload either the tubes or the output transformer.

[sol invictus]

SET amps are special tube amps, and have a lot more distortion than normal feedback designs...

BUT they have low-order distortions, and their distortion starts much earlier in the power curve and grows a lot more slowly.

So, my comments apply to SET's. They do not apply to a big tube amp with 8x 6L6GC and an output transformer the size of Youngstown... With a good design on such a push-pull device you will see little distortion until you overload either the tubes or the output transformer.

I see - OK. Is there a particular model you can point out where the difference is clearly audible? Or do you have a sense of what the requisite levels of distortion are numerically?

[jj]

I see - OK. Is there a particular model you can point out where the difference is clearly audible? Or do you have a sense of what the requisite levels of distortion are numerically?

When you see peak power distortion on the order of 3 to 10%.

[jj]

Paul Hoffmaster has cleaned up the drawings for the speaker box. If he wants, he's welcome to put up the info here.

[Paulhoff]

13912

OK, I hope that has it.

Paul

:) :) :)

Changed the tweeter box

[Paulhoff]

Surprise surprise, I still haven't heard from Stereophile so that I can sign in on the forum.

Paul

:) :) :)

[Disclord]

Audio reviewers are one step away from being paid shills for the high-end audio industry. Blind tests would ruin the whole game, because they would reveal that there are essentially no audible differences between amplifiers, DACs, CD players, etc. - and those products form what's probably a majority of the industry's business.

So it's not going to happen. At least Stereophile publishes measurements.

Are they (Stereophile) testing and publishing THD+Noise VS Level for digital gear? For the longest time they didn't do it at all because high-end digital gear usually doesn't do so hot on that test.

[sol invictus]

Are they testing and publishing THD+Noise VS Level for digital gear? For the longest time they didn't do it at all because high-end digital gear usually doesn't do so hot on that test.

Can you give an example of a piece of digital gear that doesn't do well on a THD+N test?

And yes, they do test digital gear. For example see figure 7 here (http://www.stereophile.com/digitalprocessors/108bench/index4.html):
Even at its maximum output level, the DAC1 had very low levels of harmonic distortion. With the balanced outputs driving the Audio Precision's 200k ohm load with a 24-bit tone at 0dBFS (fig.7), the subjectively benign second harmonic is the highest in level, though this lies at just –102dB left and –107dB right. The third and fourth harmonics are the only other components that rise above the –120dB line (0.0001%).

[Paulhoff]

Originally Posted by John Atkinson
Even at its maximum output level, the DAC1 had very low levels of harmonic distortion. With the balanced outputs driving the Audio Precision's 200k ohm load with a 24-bit tone at 0dBFS (fig.7), the subjectively benign second harmonic is the highest in level, though this lies at just –102dB left and –107dB right. The third and fourth harmonics are the only other components that rise above the –120dB line (0.0001%).


But pages of superfluous BS comes with that.

Paul

:) :) :)