Discussion on loudspeaker measurements as they relate - or don't - to sound

[PENG]

What if a colored speaker is such that it fits your hearing contour to make it come across as a neutral speaker in your listening environment. Is it flat or colored? If a tree falls to the ground, does it make a sound? I think this is where the subjective tsunami comes in and I point back to the one man's meat expression.

I heard that argument before and it was pointed out that it wasn't a valid point because neutral (since it is relative to original) should sound "neutral" to the individual in relative sense, regardless of their hearing contour. Now if, for example a person was a frequent un-amplified live concert goer 10 years ago while having perfect hearing, has not done so since, and then start shopping for speakers without go back to live concerts again; and his/her hearing contour has changed significantly since, then the argument could be valid. Though in that case the person will be relying on what he/she remembers how a live concert sounds like from 10 years old memory. Also in that case, if the person goes to listen to somethng live again the person would regain what should sound "neutral" to the person's base on the person's hearing contour.

 

[3db]

I heard that argument before and it was pointed out that it wasn't a valid point because neutral (since it is relative to original) should sound "neutral" to the individual in relative sense, regardless of their hearing contour. Now if, for example a person was a frequent un-amplified live concert goer 10 years ago while having perfect hearing, has not done so since, and then start shopping for speakers without go back to live concerts again; and his/her hearing contour has changed significantly since, then the argument could be valid. Though in that case the person will be relying on what he/she remembers how a live concert sounds like from 10 years old memory. Also in that case, if the person goes to listen to somethng live again the person would regain what should sound "neutral" to the person's base on the person's hearing contour.

Yes but how would that person know whether that speaker is neutral or not? May be relative to him it is but that person's hearing may deviate considerably from the norm and that speaker could be far neutral. Only specs will tell us the neutrality of a speaker but even a neutral speaker may not match our ears. Its a very valid point because we cannot step into that person's hearing contour. Unamplified music although a good indicator of what musical notes are coming from by the various instruments is still subject to the acoustic effects of the venue being played.

I'm nor arguing against neutral speakers. I prefer them any day over colored speakers for the reasons that Jerry has pointed out.

 

[AcuDefTechGuy]

I think I just answered this in post #13. Look, ADTG, if you like colored speakers, because they're fun, that's fine with me.

You know I prefer my speakers to measure +/-0.5dB & utterly smooth off-axis w/ zero cabinet resonance and stable impedance and all that if possible.

That's exactly where I stand 99% of the time.

But as we all agree, if someone prefers B&W, Wilson, Zu, Tekton, or anything else, that's cool too.

I tend to like most speakers, especially after I hear them in a good home environment.

 

[Steve81]

Here's my 2 cents:

1. IMO accuracy with respect to loudspeakers is a misnomer. There's no defined way to convert an electrical signal to acoustic output, especially with the added complexity added by the speaker/room interface.

2. In spite of #1, blind testing done by gentlemen such as Floyd Toole, Sean Olive, et. al. do indicate that subjective preferences do correlate well with certain measured criteria, i.e. frequency response (on and off axis), low end extension, etc.

Where does that leave us? If you're able to decipher the meaning of the various measurements you see, as well as understand the limitations (one or two graphs do not make a complete picture), they can be a handy guide.

 

[AcuDefTechGuy]

Here's my 2 cents:

1. IMO accuracy with respect to loudspeakers is a misnomer. There's no defined way to convert an electrical signal to acoustic output, especially with the added complexity added by the speaker/room interface.

2. In spite of #1, blind testing done by gentlemen such as Floyd Toole, Sean Olive, et. al. do indicate that subjective preferences do correlate well with certain measured criteria, i.e. frequency response (on and off axis), low end extension, etc.

Where does that leave us? If you're able to decipher the meaning of the various measurements you see, as well as understand the limitations (one or two graphs do not make a complete picture), they can be a handy guide.

What those studies tell me is that although the "majority of the subjects" preferred flat/smooth FR speakers, a certain percentage prefer speakers that are NOT flat/smooth.

Depending on the number of subjects and all that, the percentage of both sides will vary. But it tells us that there are A LOT of people who prefer speakers that are NOT flat.

Look at Wilson Audio, Zu Audio, Vienna Acoustic, B&W, Definitive Technology, Legacy Audio, Martin Logan, Magnepan, and many other speakers that don't measure flat but are preferred by so many people.

A forum member has been to my house and heard all my speakers. He has also listened to so many other speakers both ID & B&M. Yet he still goes back to Magnepan.

I've heard some Magnepan, Martin Logan, and I definitely don't prefer those speakers. I've heard Definitive & Klipsch, and I do like them.

So in the end, graphs don't matter as much as how the speakers actually sound to us.

IOW, there is no point of buying speakers that measure +/-0.5dB if people don't like how they sound.

There is NO guarantee that flat/neutral/smooth FR speakers will sound the BEST to everyone.

But, I do prefer to have the best of both worlds. I prefer speakers that measure the best and also sound the best.

IOW, if my 802D2 measured like +/-10dB, instead of +2.82/–2.79 dB, I PROBABLY would not have bought them. Probably.

My sentiment is that with 100 different speakers out there, surely people can find speakers that not only sound great but also measure great. Those speakers are out there. But there may be other reasons.

One reason may be personal aesthetics. The 802D2 sound great in my house. I could be happy if they were the only speakers I own. And although they don't measure +/-2.0dB, +2.82/-2.79 dB is NOT TERRIBLE, although off-axis could improve. But the aesthetic is incomparable IMO. In my mind's eyes, no other speakers out there look as good.

 

[English210]

I think this is dead on... and underscored the basic problem with non-selectable coloration (selectable would be a DSP or EQ).

What happens when the recording artist agrees with your preference and decides to put it in his recording? Now you've doubled down.
The errors happen to match your room? What happens when your room changes?
The errors happen to match your hearing? What about when your hearing changes?

From recording to reproduction, there are only two (and sometimes only one) thing that I *want* to color the response. The mix (and then not always) and EQ/DSP I've chosen to run.

Good points, thanks.

The room we are using does play into it though, correct? Hence the oft-repeated advice to audition prospective speakers in our own room. So back to an earlier question, can we use the detailed measurements in reviews to predict a speakers performance in our room? One of the rooms I heard the CM10's in is dead as a doornail, whereas my room at home is very live, so it's a no-brainer that what I heard in the dealer's room, while impressive, is not going to be what I'd hear at home. I come here to these forums to learn, have a little fun, but ultimately to aid in advancing my system. Another example is tweeters - I read about the RAAL tweeter, I've heard the diamond, berylium, titanium, etc, and each have their proponents and detractors. No doubt, much of that is subjective. There seems to be correlation between room size and bass response as well. So how do we 'translate' measurements into something usable for the individual?

 

[AcuDefTechGuy]

Good points, thanks.

The room we are using does play into it though, correct? Hence the oft-repeated advice to audition prospective speakers in our own room. So back to an earlier question, can we use the detailed measurements in reviews to predict a speakers performance in our room? One of the rooms I heard the CM10's in is dead as a doornail, whereas my room at home is very live, so it's a no-brainer that what I heard in the dealer's room, while impressive, is not going to be what I'd hear at home. I come here to these forums to learn, have a little fun, but ultimately to aid in advancing my system. Another example is tweeters - I read about the RAAL tweeter, I've heard the diamond, berylium, titanium, etc, and each have their proponents and detractors. No doubt, much of that is subjective. There seems to be correlation between room size and bass response as well. So how do we 'translate' measurements into something usable for the individual?

They could conduct a million DBT studies and still cannot guarantee a 100% correlation between measurement vs. preference.

 

[JonnyFive23517]

So will the same exact note (say C-major) sound differently on 2 different Steinway pianos? Which note is more accurate?

Whichever one is closes to a pure sine wave of that frequency? Lol, but that wouldn't be very interesting now would it? The harmonics add all the richness. I guess you could say that if X had a greater volume of harmonics than Y, then Y would be more accurate? But, at the end of the day, it's about what sounds good. If we wanted pure sine waves we'd all be playing on synths.

 

[English210]

They could conduct a million DBT studies and still cannot guarantee a 100% correlation between measurement vs. preference.

So the short answer to the thread's question is 'You don't! Tough! Deal with it!' ?

 

[English210]

Whichever one is closes to a pure sine wave of that frequency? Lol, but that wouldn't be very interesting now would it? The harmonics add all the richness. I guess you could say that if X had a greater volume of harmonics than Y, then Y would be more accurate? But, at the end of the day, it's about what sounds good. If we wanted pure sine waves we'd all be playing on synths.

Accuracy vs. 'sounds good'? I like it

 

[Steve81]

So the short answer to the thread's question is 'You don't! Tough! Deal with it!' ?

From the class clown anyway

In either case, as a lay person, I largely use measurements to determine what a speaker is capable of (how deep can it play, how loudly can it play, etc) and to note significant faults (serious problems in FR, resonances, etc) rather than try to predict what my favorite song is going to sound like in my room.

The room we are using does play into it though, correct?

Of course; a pair of speakers in a tile bathroom won't sound the same as if they were placed in an anechoic chamber. However, a pair of "bad" speakers won't sound like a pair of Revel Salons, KEF Reference, Philharmonic 3s, etc. regardless of the room, and it's also notable that such "good" speakers will tend to sound good in a wide variety of spaces.

 

[AcuDefTechGuy]

So the short answer to the thread's question is 'You don't! Tough! Deal with it!' ?

The answer is that nothing is pure black & white. Measurements are only part of the equation, not the whole equation.

The take-home message is to buy speakers with the following characteristics:

1) Sound great to you, which is most important.
2) Measure well because some studies show that speakers that have good on-axis and off-axis will be preferred by a lot of people.
3) Generally well-liked by your peers so that they cannot give you a hard time.

With hundreds of options available, you should be able to find those speakers.

 

[English210]

From the class clown anyway

In either case, as a lay person, I largely use measurements to determine what a speaker is capable of (how deep can it play, how loudly can it play, etc) and to note significant faults (serious problems in FR, resonances, etc) rather than try to predict what my favorite song is going to sound like in my room.

Ok, makes sense. I wouldn't expect to be able to able to predict too much, but I'll take what I can get. Learning to interpret the numbers is the next trick..

Of course; a pair of speakers in a tile bathroom won't sound the same as if they were placed in an anechoic chamber. However, a pair of "bad" speakers won't sound like a pair of Revel Salons, KEF Reference, Philharmonic 3s, etc. regardless of the room, and it's also notable that such "good" speakers will tend to sound good in a wide variety of spaces.

Also sensible. And finding the 'perfect' speaker, even for me in my room on my recordings, isn't likely. No doubt many would work. So far, the ones I've listened too all bring something to the party, but none have been 'That's IT', either.

 

[Swerd]

The room we are using does play into it though, correct? Hence the oft-repeated advice to audition prospective speakers in our own room. So back to an earlier question, can we use the detailed measurements in reviews to predict a speakers performance in our room?

Yes, if you understand a few limitations about frequency response (FR) measurements. The microphone location relative to the speaker, plus the user's understanding and proper use of time gates by the measurement software are two examples (there are more) of important variables that can make significant differences. To be able to compare FR curves of two different speakers, the measuring conditions must be similar or all bets are off.

Above roughly 250 to 300 Hz, speaker measurements (if made properly) can easily predict what you will experience at home. This is the critical upper bass - mid range - lower treble range most important to audio.

Below 250 to 300 Hz, interactions between speakers and walls/floors/ceilings have a very large effect. As a result, speaker FR curves have much less predictive value because changes in speaker or listener location can have a very large effect.

I have noticed that most DIY speaker builders who can reliably measure speakers in their homes pay close attention to speaker measurements published by two sources:

Stereophile John Atkinson usually measures speaker performance but does not write the reviews.

SoundStage Network Speaker measurements here are done by the Canadian National Research Council (NRC), and are widely considered the gold standard.

Other published measurements may or may not be done as well as these.

 

[English210]

Yes, if you understand a few limitations about frequency response (FR) measurements. The microphone location relative to the speaker, plus the user's understanding and proper use of time gates by the measurement software are two examples (there are more) of important variables that can make significant differences. To be able to compare FR curves of two different speakers, the measuring conditions must be similar or all bets are off.

Above roughly 250 to 300 Hz, speaker measurements (if made properly) can easily predict what you will experience at home. This is the critical upper bass - mid range - lower treble range most important to audio.

Below 250 to 300 Hz, interactions between speakers and walls/floors/ceilings have a very large effect. As a result, speaker FR curves have much less predictive value because changes in speaker or listener location can have a very large effect.

I have noticed that most DIY speaker builders who can reliably measure speakers in their homes pay close attention to speaker measurements published by two sources:

Stereophile John Atkinson usually measures speaker performance but does not write the reviews.

SoundStage Network Speaker measurements here are done by the Canadian National Research Council (NRC), and are widely considered the gold standard.

Other published measurements may or may not be done as well as these.

Ok, great, thanks. Would it be safe to assume JA, for example, does his measurements the same way every time, and therefore different reviews/measurement listings from Stereophile are likely to be useful for comparison?

 

[Swerd]

Would it be safe to assume JA, for example, does his measurements the same way every time, and therefore different reviews/measurement listings from Stereophile are likely to be useful for comparison?

Yes, both Stereophile and NRC graphs are done with consistency and make for useful comparisons. If they are forced to do something different in their measurements, they make sure to say so.

 

[AcuDefTechGuy]

Ok, great, thanks. Would it be safe to assume JA, for example, does his measurements the same way every time, and therefore different reviews/measurement listings from Stereophile are likely to be useful for comparison?

He and everyone else are only humans. They are not perfect and have variations that we are not privy to. It's better than nothing, though. I guess close enough.

 

[JerryLove]

So back to an earlier question, can we use the detailed measurements in reviews to predict a speakers performance in our room?

Yes... but you need to know about your room.

Of course, you can most easily adapt a flat speaker to your room. It's unlikely that your room has modes which occur only on or off axis, for example, but that's routinely where there's a problem with speakers.

 

[English210]

Yes... but you need to know about your room.

Of course, you can most easily adapt a flat speaker to your room. It's unlikely that your room has modes which occur only on or off axis, for example, but that's routinely where there's a problem with speakers.

"...need to know about your room"? As in, taking measurements? Using my current speakers? What if they are far from flat, as I suspect? Would that affect the measurements I'm taking? Without digging too deep into my equipment budget, what do you recommend I get to determine my room's 'modes'? I understand the need, but knowing as little as I do, it's intimidating to think of analyzing the room and interpreting the results.

I read a review of an earlier version of a speaker I'm interested in - Focal 1027Be, currently the 1028. Measured very well according to JA, and he measured the in room response and as of then, hadn't measured a better speaker in that room, period. The audible review stated the imaging was good, but limited in height and width compared to other speakers, which mirrored my thoughts when I heard them. I just thought at the time it might be placement-related, as they were close to the corners.

 

[fuzz092888]

For a simple way to get an idea of what your room is doing you would take quasi-anechoic measurements of the L/R. Then take LP measurements of both the L/R and average them. I like to take another one with both playing at once as well. You may also want to do this across the listening positions for both speakers. This will at least begin to give you an idea of what the room is doing to the FR response of the speakers. There's a lot more to it than that, especially since you may not be listening to your speakers on axis, but this is a start. Plus if you take REW measurements you can send the mdat files to someone else who has REW and they can get a little more from the measurements since REW doesn't just take the FR response when you take a measurement.

If you choose to invest in a USB mic and REW (which really means just a USB mic) you can send your measurement files to someone else who has REW and they can interpret them for you. All you need to do is make sure your measurement techniques are solid.

"...need to know about your room"? As in, taking measurements? Using my current speakers? What if they are far from flat, as I suspect? Would that affect the measurements I'm taking? Without digging too deep into my equipment budget, what do you recommend I get to determine my room's 'modes'? I understand the need, but knowing as little as I do, it's intimidating to think of analyzing the room and interpreting the results.

I read a review of an earlier version of a speaker I'm interested in - Focal 1027Be, currently the 1028. Measured very well according to JA, and he measured the in room response and as of then, hadn't measured a better speaker in that room, period. The audible review stated the imaging was good, but limited in height and width compared to other speakers, which mirrored my thoughts when I heard them. I just thought at the time it might be placement-related, as they were close to the corners.