Yes, of course the use of bass reflex complicates things - but I wouldn't be trying to correct uncorrectable speakers in the first place
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desirable distortion
- Thread starter nefilim
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Just bass Serge and they do it by using a laser vibration measurement of the bass cone(s) movement. I have watched them doing the KEF blade at Oxford Audio. The hardware their own design and quite compact.
Thanks Frank,
Pity they don't do the really important bit, the MF and HF. Bass is affected mostly by room modes, so whatever Devialet do will still need EQ for each room, whilst the MF and HF is much less room dependent.
Lovely idea, but they just don't go far enough.
S
They explain the process here.
It's low frequency speaker correction only, my guess is they don't want to change the 'character' of the speakers, they might get in trouble for making they all sound the same after all.
Yep, supposedly women hear better than men, especially old men who's high frequency hearing is likely none-existent, e.g.
His own (presumably younger) assistant thinks he makes bright masters
I'm interested in the idea, and think the article is well done. I've had a few cases recently when I've started playing the digital version of an album and taken it off after a few tracks to play the vinyl because it just didn't sound right, if there was a box of tricks to corrupt the digital version sometimes I'd like to play with it, I just have not idea what to try.
For LF with multiple drivers/ports/whatever, you can do a groundplane measurement, or cheat (like I do) and measure each of the sources independently using nearfield, then combine them normalized for area. Unfortunately, this can't (yet) be done easily with the AP, but it's simple with Clio and likely with other loudspeaker-oriented packages. I use Clio Pocket for this kind of measurement and it works extremely well.
svart-hvitt
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Yep, supposedly women hear better than men, especially old men who's high frequency hearing is likely none-existent, e.g.
His own (presumably younger) assistant thinks he makes bright masters
I'm interested in the idea, and think the article is well done. I've had a few cases recently when I've started playing the digital version of an album and taken it off after a few tracks to play the vinyl because it just didn't sound right, if there was a box of tricks to corrupt the digital version sometimes I'd like to play with it, I just have not idea what to try.
@Soniclife , on Katz:
you make the error of mixing up ability (nature) and skill (nurture):
(1) Of course, Bob Katz is an old man.
(2) Of course, he is a skilled listener.
You see only (1) and are blind regarding (2).
A number of people, led by Floyd Toole, believe only the bass should be corrected assuming your speakers are competent. Above that, treating first reflections may help, but many folk do not advocate correction above a fairly low frequency (~200 Hz IIRC).
I don't think it is as much of "desirable distortion" as it is "preferable distortion." A designer might compromise and prefer a little mostly benign 2nd harmonic distortion to get say a flatter response or a lower damping factor. As amplifier technology is mature those compromises need not be made for most applications, but for some speakers you would make such choices.
I have a speaker setup where .5% mostly 2nd harmonic distortion @1w and little or no damping works better than 100wpc ab integrated with a ton of negative feedback, super low distortion, and super high damping. Those speakers' design also has choices that mainstream speakers probably wouldn't consider today given the availability of cheap, clean watts in modern amplifiers. But they exist, and so too must amplifiers that serve them.
I have a speaker setup where .5% mostly 2nd harmonic distortion @1w and little or no damping works better than 100wpc ab integrated with a ton of negative feedback, super low distortion, and super high damping. Those speakers' design also has choices that mainstream speakers probably wouldn't consider today given the availability of cheap, clean watts in modern amplifiers. But they exist, and so too must amplifiers that serve them.
I think you may be confusing an anechoic response with an in-room response. Toole advocates correcting for the in-room response for the bass only, but equalising (i.e. correcting) for the anechoic response at MF and HF. Or better still, having loudspeakers that have a flat anechoic response without needing additional EQ.
First and subsequent reflections are best left untreated according to Toole, subject to the loudspeaker's own polar diagram looking benign, and the room's reverberation time being suitably low and even with frequency, which most normally furnished rooms are.
My own experience is that unless the room is grossly unsuitable, if a room is suitable for everyday living, conversations, domestic sounds, then it's equally suitable for playing music. If a room sounds harsh and echoey for HiFi, it will be unpleasant for conversation, watching TV or whatever.
According to Toole, and very much in line with my own experience is that we have the ability to 'listen through' the room so a nice room at home is a nice room for HiFi and of course, vice-versa. This assumes loudspeakers with a flat on-axis response and sensible directionality, which is unfortunately, less true of many 'boutique' designs. Have you seen the frequency response of Boenikes?
S.
I should have clarified that the second comment, about treating first reflections, was independent of the first, referencing Toole's work. My room is very dead; pretty sure Dr. Toole would not like it, but it sounds good to me. My main speakers are decent, Revel Salon2's.
Grave
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This guy apparently knows nothing about audio playback. I do not care if he is a famous mastering engineer.
A hi-fi headphone set up should consist of:
A transparent audio format.
A transparent DAC/amp.
Whatever the hell headphones you want because they are never transparent.
Any DAC/amp which distorts the sound audibly is, by definition, not high fidelity.
I would think that anyone on an "audio science review forum" would agree with this.
A hi-fi headphone set up should consist of:
A transparent audio format.
A transparent DAC/amp.
Whatever the hell headphones you want because they are never transparent.
Any DAC/amp which distorts the sound audibly is, by definition, not high fidelity.
I would think that anyone on an "audio science review forum" would agree with this.
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When a square-wave begins to sound like a sinewave:
THD of the square wave is 48.3%. https://www.allaboutcircuits.com/technical-articles/the-importance-of-total-harmonic-distortion/
THD of the square wave is 48.3%. https://www.allaboutcircuits.com/technical-articles/the-importance-of-total-harmonic-distortion/
Or they can't accurately measure small fast movements of HF membrane..
You can readily do the expansion and generate the magnitude of the terms needed to create a square wave, but technically those are not distortion terms; they are present in the original signal. There is only distortion to the extent that the harmonics do not match the level of the original harmonics decomposed from the source square wave. THD is normally referenced using a single-tone input. IMD, a test I would like to see performed more often), uses two (usually) or more tones, and the distortion terms included non-harmonic frequencies.
Someplace on ASR is an article discussing how to make a square wave that I posted over on WBF and Amir ported over here. It is under his name as author, not mine, so a search on "square wave" with Amir (amirm) as author should turn it up.
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Yes, thank you!
Does anybody know why Stereophile use a 10kHz square wave in their tests of electronics? None of the harmonics are audible! Hi Fi News used to use 40Hz square wave, which made sense to me since lots of the harmonics are audible and it is lower than mains frequency so may show up power supply limitations.
Probably because it impresses those that don't understand what square-wave testing shows.
Having said that, a 10kHz square wave may show up HF instability that a 40Hz square wave won't, but a 40Hz square wave will show up LF instability and poor power supply regulation which a 1k or 10k won't. There's a place for both, and when I test amplifiers I start with a 1kHz square wave, which should look nice and square on a 'scope, with no LF tilt or overshoot. If that looks OK, then I may not bother to do a lower and higher frequency square wave test, but as it's so easy to do, I usually will anyway. If I were a magazine and only had space for one square wave image, I'd probably go for 1Khz into a capacitative load. HFN used to use 8ohm in parallel with 2uF as a simulated ESL load for their square wave tests.
S
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