Frequency response graphs

[Swerd]

I actually am putting almost all the weight on the impulse responses, which suggest that the frequency responses are likely correct.

Of those speakers mine is the only low Q speaker of the bunch. The others are high Q, which from the design is what you would expect.

Yes, I agree that the impulse responses are further evidence that those speakers have high Q designs. My comments were intended for ADTG, not you. Maybe I was unclear.

 

[Irvrobinson]

I personally think you are all forgiving of this because it is so much the norm in speakers you are used to it.

No, I forgive it because on a recording of a kick drum made in the same room the recording sounds very accurate. Part of it could be that in a residential-sized room the reflections overwhelm the time domain sloppiness. Or not...

Actually, I have heard speakers with very good impulse responses, the Quad and Sound Lab electrostatics, and they do sound very different than any point source speakers I've heard, including the Linkwitz Orions. I can't say they are more accurate, especially the Quad, since it's weak below 50Hz and that alone makes it sound different, but different they are. It is interesting though that the only current commercial speaker I'm really tempted by is the Sound Lab A-1PX. Too big, too expensive though.

What sort of smoothing did you use on that frequency response graph? Perhaps you told me once, but I forgot. 1/6th octave?

 

[TLS Guy]

No, I forgive it because on a recording of a kick drum made in the same room the recording sounds very accurate. Part of it could be that in a residential-sized room the reflections overwhelm the time domain sloppiness. Or not...

Actually, I have heard speakers with very good impulse responses, the Quad and Sound Lab electrostatics, and they do sound very different than any point source speakers I've heard, including the Linkwitz Orions. I can't say they are more accurate, especially the Quad, since it's weak below 50Hz and that alone makes it sound different, but different they are. It is interesting though that the only current commercial speaker I'm really tempted by is the Sound Lab A-1PX. Too big, too expensive though.

What sort of smoothing did you use on that frequency response graph? Perhaps you told me once, but I forgot. 1/6th octave?

Yes, it was 1/6 octave.

I think the main reason you don' t have much trouble with the kick drum is that the frequency of the thump is in the 60 to 100 Hz range. The slap is in the 1.5 KHz to 3 KHz range. So you are not really hitting the range where the cabinet tuning is operative in the Revels. The driver augmentation from the tuning resonance is from 18 Hz to 60 Hz, maximal at 23 Hz.

For speakers like the Kef and Revel we are talking about the instruments hitting the area of bass tuning. These would be the double bass, lower strings of the piano, and especially the harp, the orchestral bass drum, the contrabassoon, the tuba, the bass trombone, and of course the pipe organs. Pipe organs are a special case, as like loudspeakers they have Q and you have to know your organ.

However tracker organs are a very good test to reveal the ills of high Q speakers.

My speakers are unusual in that tuning support covers 2.5 octaves in all, which makes the design of the lines exacting. There is a lot of opportunity for trouble. So I was relieved to say the least of it that things worked out so well and there is an impulse response close the ideal. The impulse response is also a measure of inter driver delay, and so very careful attention to the crossovers is also important.

But you are right about low Q speakers sounding different, they do. For the accurate reproduction of program I listen to it is highly desirable.

I think it is very controversial interpreting frequency response measurements made under home conditions. I don't think you can ever be certain that room effects are not skewing the result. Having said that though the measurement of a low Q speaker is less likely to show room artifact. The reason being is that there is less time to excite room resonance. The KEF and the Revel are ringing about 16 times longer than mine. Certainly low Q speakers excite room resonances less then high Q ones for obvious reasons.

 

[Irvrobinson]

Yes, it was 1/6 octave.

I think the main reason you don' t have much trouble with the kick drum is that the frequency of the thump is in the 60 to 100 Hz range. The slap is in the 1.5 KHz to 3 KHz range. So you are not really hitting the range where the cabinet tuning is operative in the Revels. The driver augmentation from the tuning resonance is from 18 Hz to 60 Hz, maximal at 23 Hz.

For speakers like the Kef and Revel we are talking about the instruments hitting the area of bass tuning. These would be the double bass, lower strings of the piano, and especially the harp, the orchestral bass drum, the contrabassoon, the tuba, the bass trombone, and of course the pipe organs. Pipe organs are a special case, as like loudspeakers they have Q and you have to know your organ.

However tracker organs are a very good test to reveal the ills of high Q speakers.

My speakers are unusual in that tuning support covers 2.5 octaves in all, which makes the design of the lines exacting. There is a lot of opportunity for trouble. So I was relieved to say the least of it that things worked out so well and there is an impulse response close the ideal. The impulse response is also a measure of inter driver delay, and so very careful attention to the crossovers is also important.

But you are right about low Q speakers sounding different, they do. For the accurate reproduction of program I listen to it is highly desirable.

I think it is very controversial interpreting frequency response measurements made under home conditions. I don't think you can ever be certain that room effects are not skewing the result. Having said that though the measurement of a low Q speaker is less likely to show room artifact. The reason being is that there is less time to excite room resonance. The KEF and the Revel are ringing about 16 times longer than mine. Certainly low Q speakers excite room resonances less then high Q ones for obvious reasons.

I don't know how to accurately measure the fundamental frequencies of my wife's 22" DW kick drum in my home, but the RTA display makes it look a heck of a lot lower than 60Hz, and it sounds and feels a lot lower than 60Hz. I had guessed there's a shock wave in the 40-something Hz range. My 18" sub looks big until it's side-by-side with that drum.

Anyway, I'm so forgetful, I have heard a speaker with a spectacular impulse response *and* awesome bass response, the Dunlavy SC-V. Of course, that was a long time ago, making any comparisons sort of laughable, and I wasn't using the kick drum recordings in question during the auditions because they didn't exist, and it was in a very different room than I've ever had at home (a much larger room at a dealer). Nonetheless, all of these numerous caveats aside, I don't remember the bass being so different as the Sound Lab, or even calling itself out as so different, per se. My issues with the Dunlavy were in the tweeter's range and perhaps I focused on that during the auditions to the detriment of my analysis of the bass response. But the Dunlavy's bass was very "tight" to say the least, and it sounded great on the bass-heavy Telarc recording of Malcolm Frager playing Chopin on a Bosendorfer. I'm stupidly trying to compare speakers heard many years apart in different rooms, but I think the Dunlavy and the Sound Lab sound quite different on that recording. I suspect the other characteristic differences of the speakers make far more audible differences than the impulse response accuracy, which I believe is similar.

I'm also doing something on my current system which I was told (and I thought) would be a dumb thing to do from a time domain standpoint, and that's mix the sealed Velodyne sub with the ported Revels running full-range. I can't hear any qualitative difference between the Revels crossed over to the Velodyne at 80Hz and the Revels running full range without the sub, and since the system measures and sounds better using the full-range strategy for the Revels in the frequency domain I use it that way, with the sub providing "filler" rather than being the primary reproducer. Anyway, that the supposed no-no sounds so good and accurate in-room is what makes me wonder if room effects are swamping the time domain problems in my system.

Your speakers are unique and different from anything I've ever heard to my recollection, so perhaps they are different-sounding in the bass and better than either the Dunlavy, the Sound Lab, or my old sealed ADS L1530s and M15s. I'm just not sure how to audibly differentiate between the time domain distortion, which we all know is there on ported speakers, and whatever room effects there are.

I also agree that measuring speakers in a residential room is problematic. My system has a similarly impressive response curve measured with 1/6th octave smoothing, and I'm sure our systems probably sound different enough to allow us to pass single-blind comparison tests. (Sorry, I can't post the curves at the moment, as I don't have access to that data on this computer.) To me that means the frequency response measurements are little more than in-room tuning tools.

 

[AcuDefTechGuy]

You're generalizing too much, and forcing broad conclusions that really can't be made. I think you do know better. I only said peaks in this bass range suggests high Q. It doesn't prove it.

There clearly are other room-related reasons why a frequency response curve can have the appearance of bass peaks. It depends on the details of how the frequency response curve was measured.
Are you really suggesting that Philharmonic or Salk speakers are designed with high Q bass peaks? Or are you playing Devil's Advocate?

Dennis doesn't show frequency response measurements below 200 Hz because he doesn't have an anechoic room, or the capacity that Stereophile has to simulate one. He readily admits that, and I think that's being honest.

I was showing examples of what you said regarding the bass hump and how it only suggests but does not prove the speakers have high Q.

I was suggesting that although the Salk and Phils may have a Q of 0.5, if they were measured by Stereophile, the bass hump may still show.

Of course, I always think that if the speaker sounds great, then it is great.

 

[AcuDefTechGuy]

Of those speakers mine is the only low Q speaker of the bunch. The others are high Q, which from the design is what you would expect.

You are comparing different measurements done by different people at different places - your own PERSONAL measurement vs. Stereophile 3rd party measurement.

Here is a FR from Sound & Vision Magazine which shows the Salon2 as 28 Hz to 20 kHz +/-1.3 dB with no bass "hump" and no excuses about why there is a bass hump.

Different locations, different time, different people, different equipment, different software - just different.

In Revel's own PERSONAL anechoic lab, the Salon 2 is +/-0.5 dB from 29 Hz to 18 kHz, which clearly means no bass hump (+/- 0.5dB).

Is your speaker +/- 0.5dB from 29Hz-18kHz? Or even +/- 1.3dB from 28Hz-20kHz?

 

[AcuDefTechGuy]

I think it is very controversial interpreting frequency response measurements made under home conditions.

But as long as the interpretation is done by you and in your house, it's more accurate?

The advantage of building your own speakers and measuring it yourself in your own house is that no one can prove that your DIY speaker is actually not as great as the best speakers out there.

You can make all kinds of claims about how it has the best design and best Q and best measurement, etc., and no one can really dispute.

But you also can't prove that your speakers have the best Q and best measurement, etc., either because you are comparing different measurement done by different people at different locations using different equipment and different software.

 

[AcuDefTechGuy]

People, especially new enthusiasts, need to understand that "measurement" is only a good starting point. Many of us love measurement and would not buy speakers that have terrible measurement.

But unless you are comparing the speakers using the same room, system, equipment, software, technique, etc., any measurement conclusions are questionable.

And in the END, how the speakers actually sound to YOU is the salient thing.

Sit back, relax, and actually enjoy the movies, TV shows, and music and forget you are listening to the speakers, but rather you are experiencing the event itself.

 

[TLS Guy]

People, especially new enthusiasts, need to understand that "measurement" is only a good starting point. Many of us love measurement and would not buy speakers that have terrible measurement.

But unless you are comparing the speakers using the same room, system, equipment, software, technique, etc., any measurement conclusions are questionable.

And in the END, how the speakers actually sound to YOU is the salient thing.

Sit back, relax, and actually enjoy the movies, TV shows, and music and forget you are listening to the speakers, but rather you are experiencing the event itself.

But as long as the interpretation is done by you and in your house, it's more accurate?

The advantage of building your own speakers and measuring it yourself in your own house is that no one can prove that your DIY speaker is actually not as great as the best speakers out there.

You can make all kinds of claims about how it has the best design and best Q and best measurement, etc., and no one can really dispute.

But you also can't prove that your speakers have the best Q and best measurement, etc., either because you are comparing different measurement done by different people at different locations using different equipment and different software.

I can claim my speakers to be low Q, as I have two means to asses it. I and others have confirmed that when these lines are damped to the point of only one peak of impedance and not two, then system Q is in the neighborhood of 0.5. The impulse measurement confirms my impedance measurements. So I have two pieces of data agreeing.

The other speakers just by the nature of their design will not have a Q in this range. Now Q is NOT something you will see in an FR measurement, but has a profound impact on the sound if the speaker in the lower octaves. So I can be certain the bass of my system will sound different to the rest.

I agree and have already commented on FR graphs being dependent on the condition of test. However as stated above, I can be confident of the Q of my system.

After 60 plus years of building and studying pipes, I have learned a thing or two!

 

[Irvrobinson]

People, especially new enthusiasts, need to understand that "measurement" is only a good starting point. Many of us love measurement and would not buy speakers that have terrible measurement.

But unless you are comparing the speakers using the same room, system, equipment, software, technique, etc., any measurement conclusions are questionable.

And in the END, how the speakers actually sound to YOU is the salient thing.

Sit back, relax, and actually enjoy the movies, TV shows, and music and forget you are listening to the speakers, but rather you are experiencing the event itself.

We all know your position regarding "be happy if it sounds good", but many of us are chasing accuracy, because we value authenticity. Being happy isn't enough. No, you can't ever completely reproduce the acoustic experience of one room in another, but I have heard speakers that sound good and are grossly inaccurate. Upon hearing a more accurate speaker it always makes me dissatisfied, no matter how good I thought the lousy speaker sounded. How it sounds to me isn't enough.

When I was quite young I had what turned out to be very colored speakers. I remember playing the song Paradise by Dashboard Light, by Meatloaf, and falling in love with Ellen Foley's voice. Well, at least in lust. She had the sexiest voice I'd ever heard. A couple of years later I heard that recording on a pair of uncolored Quads and my illusion was shattered. The voice I had lusted for was a coloration. Foley still had a great voice, and it sounded real on the Quads, but she didn't sound like she did before. It was a very formative experience.

 

[AcuDefTechGuy]

We all know your position regarding "be happy if it sounds good", but many of us are chasing accuracy, because we value authenticity. Being happy isn't enough. No, you can't ever completely reproduce the acoustic experience of one room in another, but I have heard speakers that sound good and are grossly inaccurate. Upon hearing a more accurate speaker it always makes me dissatisfied, no matter how good I thought the lousy speaker sounded. How it sounds to me isn't enough.

When I was quite young I had what turned out to be very colored speakers. I remember playing the song Paradise by Dashboard Light, by Meatloaf, and falling in love with Ellen Foley's voice. Well, at least in lust. She had the sexiest voice I'd ever heard. A couple of years later I heard that recording on a pair of uncolored Quads and my illusion was shattered. The voice I had lusted for was a coloration. Foley still had a great voice, and it sounded real on the Quads, but she didn't sound like she did before. It was a very formative experience.

And we all know your position on the one and only universal "accuracy".

You speak as if there is one universal "accuracy".

So what's more "accurate" when 2 Steinway grand pianos sound differently? When 2 cellos sound differently? When the sound from 2 seats in the same concert hall sound differently?

No matter how people try to justify their own systems (by claiming more accuracy and expertise), it comes down to whether you prefer one piano over another, one violin over another, one drum over another, one guitar over another, one concert over another, one symphony conductor over another.

Measurement and "accuracy" only get you so far. ENJOYMENT of the sound is the GOAL.

 

[AcuDefTechGuy]

After 60 plus years of building and studying pipes, I have learned a thing or two!

And you think you are the ONLY one?

Other speaker designers from Linkwitz, Revel, KEF, TAD, Ascend, Salk/Philharmonic, PSB, RBH, etc., just don't know how to design the great sounding speakers with low Q and great measurement because they didn't DIY? Because they designed speakers for their companies? Because they just don't know how to?

 

[Irvrobinson]

And we all know your position on the one and only universal "accuracy".

You speak as if there is one universal "accuracy".

Outstanding!

So what's more "accurate" when 2 Steinway grand pianos sound differently? When 2 cellos sound differently? When the sound from 2 seats in the same concert hall sound differently?

Accuracy is when a system reproduces the instruments in such a way that they characterized enough that the listener can tell the difference. The mikes are only in one place for the recording. There's only one place where the soundstage and the sound spectrum coincide. You know this.

No matter how people try to justify their own systems (by claiming more accuracy and expertise), it comes down to whether you prefer one piano over another, one violin over another, one drum over another, one guitar over another, one concert over another, one symphony conductor over another.

Measurement and "accuracy" only get you so far. ENJOYMENT of the sound is the GOAL.

I don't agree. Authenticity is a goal unto itself. I don't agree with any of your analogies.

 

[AcuDefTechGuy]

I don't agree. Authenticity is a goal unto itself. I don't agree with any of your analogies.

Well there's a shocker.

None of us have to agree.

I do prefer speakers that measure accurately on-axis and off-axis and have tight accurate musical bass. But they better sound great to me and I better enjoy them fully too.

So your ULTIMATE goal is not the enjoyment of the sound, huh? Interesting.

As if you knew how it REALLY SOUNDED when the live recording took place right on stage where the microphone was placed right on stage and you sat right on stage exactly where the microphone was placed.

 

[Irvrobinson]

As if you knew how it REALLY SOUNDED when the live recording took place right on stage where the microphone was placed right on stage and you sat right on stage exactly where the microphone was placed.

When I make the recording I do know how the live performance sounded.

This is me ignoring your condescending comment about enjoyment.

 

[AcuDefTechGuy]

When I make the recording I do know how the live performance sounded.

This is me ignoring your condescending comment about enjoyment.

Oh, I see. So your in-home non-blinded observation of the drums proves that your speakers are 100% accurate and authentic to ALL live performances?

BTW, devil's advocate is my middle name.

 

[Irvrobinson]

Oh, I see. So your in-home non-blinded observation of the drums proves that your speakers are 100% accurate and authentic to ALL live performances?

I have recorded a lot more than drums. That was just an example I used earlier in this thread. And, yes, accurate reproduction on one recording is an indicator (though admittedly far from a perfect one) of overall accuracy, so it is IMO a better indicator than just "I like how this sounds".

 

[AcuDefTechGuy]

I have recorded a lot more than drums. That was just an example I used earlier in this thread. And, yes, accurate reproduction on one recording is an indicator (though admittedly far from a perfect one) of overall accuracy, so it is IMO a better indicator than just "I like how this sounds".

No matter how many home recordings you've done, it is still only your opinion that your speakers are "accurate" or "authentic".

Others have listened to live concerts and they also believe their speakers sound "accurate" and "authentic".

But never will YOUR opinion guarantee that ANYONE else will like the speakers you like or the "accurate" and "authentic" sound you like.

Thus, I say people must like and enjoy the sound of the speakers. You cannot argue when someone says he loves the sound of the speakers. But you can argue how "accurate" or "authentic" the speaker sounds.

Your goal could be the authenticity experience or it could be the better-than-being-there experience. We all have different goals. But the end game is always the same - you enjoy the sound.

 

[Irvrobinson]

No matter how many home recordings you've done, it is still only your opinion that your speakers are "accurate" or "authentic".

Others have listened to live concerts and they also believe their speakers sound "accurate" and "authentic".

But never will YOUR opinion guarantee that ANYONE else will like the speakers you like or the "accurate" and "authentic" sound you like.

Thus, I say people must like and enjoy the sound of the speakers. You cannot argue when someone says he loves the sound of the speakers. But you can argue how "accurate" or "authentic" the speaker sounds.

Your goal could be the authenticity experience or it could be the better-than-being-there experience. We all have different goals. But the end game is always the same - you enjoy the sound.

I'm failing to see the logic of your argument, or your seemingly vituperative tone, but you've worn me out. This thread is all yours.

 

[lsiberian]

And you think you are the ONLY one?

Other speaker designers from Linkwitz, Revel, KEF, TAD, Ascend, Salk/Philharmonic, PSB, RBH, etc., just don't know how to design the great sounding speakers with low Q and great measurement because they didn't DIY? Because they designed speakers for their companies? Because they just don't know how to?

You telling me Dennis Murphy or Linkwitz never did DIY? Seriously man you are just being silly.