Psychoacoustics, Audibility of Great Sound

gene

gene

Audioholics Master Chief
Administrator
There have been a lot of articles and studies on the subject of psychoacoustics and the relative audibility of various acoustic phenomena and artifacts. Which measurements correlate most closely to the listening experience? Is phase really audible? Can we detect low levels of harmonic distortion and is it objectionable?

Steve Feinstein shares his personal journeys of psychoacoustics that helped him lead the design of many famous audio products like the Bose Wave Radio, Boston Acoustics Sub/Sat systems, and more.

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Read: Psychoacoustics & Audibility of Great Sound
 
3db

3db

Audioholic Slumlord
It's a good thing to read other points of view but this still remains my bible to all things acoustic and psychoacoustics.

Sound Reproduction: The Acoustics and Psychoacoustics of Loudspeakers and  Rooms: Toole, Floyd: 9781138921368: Books - Amazon.ca
 
ryanosaur

ryanosaur

Audioholic Overlord
Excellent article, Steve.
I really like your addition of asymmetric placement for subwoofers and use that technique myself.
 
Eppie

Eppie

Audioholic Ninja
Enjoyable article. While speaker phase might not be as critical in a home environment, it has a very big impact in car audio systems. I would surmise that in a car environment the speaker proximity and small compartment size can lead to dramatic phase cancellation. I could always tell when a client had the polarity wrong on one of the rear speakers because it would invariably kill the bass. It's interesting that the effect is not so predominant in home applications.
 
lovinthehd

lovinthehd

Audioholic Jedi
Great article! Enjoyed that a lot, plus it brought back some gear memories for sure (having had the 2270 and Original Large Advents).

ps I would have definitely gone to the Santana/Tower of Power show instead, tho :) Thanks for not going?
 
G

geodon005

Audiophyte
Gene:

In your Editorial Note on Blending Subs with Tower Speakers, you said it was OK to raise the crossover "IF you're running two subs up towards the front of the room" (and use EQ). I have an older SVS Sub (only 1 sub) matched with 4 Klipsch R-625FA tower speakers, and I use Audyssey XT32 with the Audyssey app for EQ. Would I be better served with a lower crossover (currently at 80 HZ)?
 
NINaudio

NINaudio

Audioholic Samurai
I had my old Boston Acoustics Lynnfield VR 950's for 20 years up until a year and a half ago when I got my Salks. They continue on in service at a friend's place now. They always sounded great to me for something that was an "entry level" speaker. I had BA's in my car systems for years as well and they never disappointed.
 
B

brian6751

Audioholic Intern
I love articles like this and the myth busters
 
TLS Guy

TLS Guy

Seriously, I have no life.
I absolutely agree with everything in this article and it agrees with my experience.

I agree that a full range integrated speakers are superior to speakers/sub. The problem is that it is difficult and expensive to engineer. For optimal results and if honest, essential, for the speaker to be at least partially active. My endeavors showed me that for optimal results a full range option was the best sounding solution. That is why I chose that option. The right and left speakers and rear backs are full range speakers. The 3db point of the center is 45Hz, with 12 db per octave roll off, and the surrounds -3db point 52 Hz 12 db per octave roll off. Only the ceiling speakers are crossed over and the others run full range. The sub channels are mixed into the right and left fronts starting at 40 Hz. You can get good room curves with other options, but running as described above produces easily the best listening experience.

I have mentioned the room power response many times. Yes, you need an accurate near field axis response. But if the combination of the first arrival response and reflected response don't closely match all is lost. I think if you have the luxury of a large enough room, the best sound of good speakers is in the far field.

I agree that absolute phase is a crock. However, many deny the aberrations caused by phase, and therefore time discrepancies, that do not affect FR. However I have pointed out many times, that you can design a speaker with a perfect FR, but with enough phase/time aberrations it is totally useless. Steve correctly pointed out that phase aberrations are particularly deleterious in the midband. This in my view when designing speakers with conventional crossover technology, you have to be very conscious of where you place the crossover. I avoid crossing over drivers from 700 Hz to 2.5KHz like the absolute plague. If you do that, you will have a speaker that is wide of the mark. If I can I like to avoid crossing over between 500 Hz and 4KHz.

Now there is a bit of a caveat to the above which masks it. That is recording techniques with mics scattered all over the place, and placed far too close to instruments. This sort of engineering malpractice is the rule rather than the exception. So the result is a recording just fully peppered with phase/time anomalies, and masks the speaker issues. If you make phase coherent recordings with minimalist mic techniques you will hear these speaker anomalies without difficulty.
The Detroit symphony have their own high end AV facilities. They have gone to the three spaced omni technique and no longer pepper the stage with mics. The sound is stunningly good, and incredibly realistic, with exceptional imaging, sounic depth of field and realistic ambience. You really feel you are there. It is also helped by a phenomenally good 4K video. This is the way it should be done.

Hopefully there will be a move to speakers connected to the home ethernet and fully active speakers with DSP for total time delay correction. This should be able to be done without requiring remortgage of the home. I am very optimistic this will come. I would advise anyone building a home theater, to put AC power at every speaker location and conduit for ethernet cat 6 at least. So the pre/pro will feed the speakers via ethernet connection. This will happen and will be major step forward. Then finally we will see the back of those awful troublesome receivers, which are well past their sell by date, if they ever had one.
 
gene

gene

Audioholics Master Chief
Administrator
Gene:

In your Editorial Note on Blending Subs with Tower Speakers, you said it was OK to raise the crossover "IF you're running two subs up towards the front of the room" (and use EQ). I have an older SVS Sub (only 1 sub) matched with 4 Klipsch R-625FA tower speakers, and I use Audyssey XT32 with the Audyssey app for EQ. Would I be better served with a lower crossover (currently at 80 HZ)?
No because I would stick to 80Hz for home theater application. Work on getting the best time alignment of your sub with your mains and use REW to help you guide this.
 
TLS Guy

TLS Guy

Seriously, I have no life.
No because I would stick to 80Hz for home theater application. Work on getting the best time alignment of your sub with your mains and use REW to help you guide this.
Thanks for the winner designation Gene, much appreciated. This is an important topic, about which there is so much misunderstanding.

While I have your attention, we seem to be getting increasing numbers of posts about vintage equipment. I think you should give serious consideration to having a vintage forum. I do think we need to remember where we came from. That is why I keep equipment spanning over 60 years in the system. Visitors find it fascinating.
Talking of which you are welcome as a guest here anytime.
 
gene

gene

Audioholics Master Chief
Administrator
Thanks for the winner designation Gene, much appreciated. This is an important topic, about which there is so much misunderstanding.

While I have your attention, we seem to be getting increasing numbers of posts about vintage equipment. I think you should give serious consideration to having a vintage forum. I do think we need to remember where we came from. That is why I keep equipment spanning over 60 years in the system. Visitors find it fascinating.
Talking of which you are welcome as a guest here anytime.
Great suggestion. Can you help me write up a short summary of what that section would entail and I can look at building that forum during the weekend?
 
TLS Guy

TLS Guy

Seriously, I have no life.
Great suggestion. Can you help me write up a short summary of what that section would entail and I can look at building that forum during the weekend?
Will do.
 
highfigh

highfigh

Seriously, I have no life.
1) Now there is a bit of a caveat to the above which masks it. That is recording techniques with mics scattered all over the place, and placed far too close to instruments. This sort of engineering malpractice is the rule rather than the exception. So the result is a recording just fully peppered with phase/time anomalies, and masks the speaker issues. If you make phase coherent recordings with minimalist mic techniques you will hear these speaker anomalies without difficulty.

The Detroit symphony have their own high end AV facilities. They have gone to the three spaced omni technique and no longer pepper the stage with mics. The sound is stunningly good, and incredibly realistic, with exceptional imaging, sounic depth of field and realistic ambience. You really feel you are there. It is also helped by a phenomenally good 4K video. This is the way it should be done.

2) Hopefully there will be a move to speakers connected to the home ethernet and fully active speakers with DSP for total time delay correction. This should be able to be done without requiring remortgage of the home. I am very optimistic this will come. I would advise anyone building a home theater, to put AC power at every speaker location and conduit for ethernet cat 6 at least. So the pre/pro will feed the speakers via ethernet connection. This will happen and will be major step forward. Then finally we will see the back of those awful troublesome receivers, which are well past their sell by date, if they ever had one.
1) I know you don't like pop music and as far as I know, you listen to classical exclusively, but if you were to listen to a wide range of other types, I think you would be astounded by the wide range of sound quality- some is actually very good, but so much is so bad that I can't imagine wanting my name in the credits. Assuming the sound through good speakers reveals the inverse of how it needed to be adjusted through the monitors, I have to think the studios had boom/crash speakers and used them to make the final decisions, rather than something smaller, but better. I guess the speakers from the '70s may have been so popular because they were a decent match for the sound they were producing, but using good speakers now shows how bad it really is. Fortunately, somehow, the master tapes are relatively intact and the remasters sound much better.

2) I agree that using ethernet would be a good move, but I also expect people to have a hard time getting it to work because people seem to have a severe allergy to paying someone for this kind of work. Won't totally eliminate ground loops, but.....

Anything to eliminate HDMI is a giant leap for mankind.
 
TLS Guy

TLS Guy

Seriously, I have no life.
1) I know you don't like pop music and as far as I know, you listen to classical exclusively, but if you were to listen to a wide range of other types, I think you would be astounded by the wide range of sound quality- some is actually very good, but so much is so bad that I can't imagine wanting my name in the credits. Assuming the sound through good speakers reveals the inverse of how it needed to be adjusted through the monitors, I have to think the studios had boom/crash speakers and used them to make the final decisions, rather than something smaller, but better. I guess the speakers from the '70s may have been so popular because they were a decent match for the sound they were producing, but using good speakers now shows how bad it really is. Fortunately, somehow, the master tapes are relatively intact and the remasters sound much better.

2) I agree that using ethernet would be a good move, but I also expect people to have a hard time getting it to work because people seem to have a severe allergy to paying someone for this kind of work. Won't totally eliminate ground loops, but.....

Anything to eliminate HDMI is a giant leap for mankind.
You won't get rid of HDMI, it is just that the pre/pro will connect to the speakers via your home Ethernet via your router. It could be a wireless connection, but hard wire is always best for these applications. I would also like to see the back of HDMI, but dumping it would make a lot of equipment obsolete. I will never agree that the draconian complexity of that level of DRM was, and is not necessary. The rate of the handshakes in current repeater architecture is totally absurd and over the top.
 
3db

3db

Audioholic Slumlord
1) I know you don't like pop music and as far as I know, you listen to classical exclusively, but if you were to listen to a wide range of other types, I think you would be astounded by the wide range of sound quality- some is actually very good, but so much is so bad that I can't imagine wanting my name in the credits. Assuming the sound through good speakers reveals the inverse of how it needed to be adjusted through the monitors, I have to think the studios had boom/crash speakers and used them to make the final decisions, rather than something smaller, but better. I guess the speakers from the '70s may have been so popular because they were a decent match for the sound they were producing, but using good speakers now shows how bad it really is. Fortunately, somehow, the master tapes are relatively intact and the remasters sound much better.

2) I agree that using ethernet would be a good move, but I also expect people to have a hard time getting it to work because people seem to have a severe allergy to paying someone for this kind of work. Won't totally eliminate ground loops, but.....

Anything to eliminate HDMI is a giant leap for mankind.
I agree that one cannot make an accurate assessment of recording quality based on a single genre of music. For instance, I 've bought a lot of new blues artists lately and the majority of those recordings were very good to stellar. But not all of them were that good. If I used blues only, I would say that the quality of recording has improved with time.

I have a good cross section of classical recordings with old and new recordings and I find the recording qualities are mixed for old and new. Im still looking for a good recording of Beethoven's Piano Concerto #5 which Im unable to find. My biggest issue with classical recordings is the timing which I blame soley on the conductor. Ive heard some absolutely horrid recordings were the conductor hurried the orchestra through a piece and it totally closed off the piece music without letting it breathe. Then there's the opposite where the piece was played to slow which makes the piece loose energy. Im extremely picky over the timing. It truly makes or breaks the complexities of classical music.
 
highfigh

highfigh

Seriously, I have no life.
I agree that one cannot make an accurate assessment of recording quality based on a single genre of music. For instance, I 've bought a lot of new blues artists lately and the majority of those recordings were very good to stellar. But not all of them were that good. If I used blues only, I would say that the quality of recording has improved with time.

I have a good cross section of classical recordings with old and new recordings and I find the recording qualities are mixed for old and new. Im still looking for a good recording of Beethoven's Piano Concerto #5 which Im unable to find. My biggest issue with classical recordings is the timing which I blame soley on the conductor. Ive heard some absolutely horrid recordings were the conductor hurried the orchestra through a piece and it totally closed off the piece music without letting it breathe. Then there's the opposite where the piece was played to slow which makes the piece loose energy. Im extremely picky over the timing. It truly makes or breaks the complexities of classical music.
Was the recording quality of those Blues recordings better than the music and/or musicianship?
 
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