Quality speakers for classical music with high output/volume

[excelsius]

This was explained before, but I feel it need additional explanation again , with examples:

1. An active "satellite" speaker (here: Neumann KH 150) with ideally flat frequency response is capable of, for example, maximum SPL = 110 dB (with less than 3% THD) above 200 Hz, and SPLmax = 100 dB (with < 3% THD) below 100 Hz. Because active loudspeakers have internal amplifiers, maximum SPL is determined either by maximum available power from the amplifier before clipping or by maximum THD from the loudspeaker. Of course, asking (internal) amplifier to output more power lead to amp clipping and excessive THD.
If we use 100 Hz high-pass filter for that "satellite" and add sub below 100 Hz, available maximum satellite SPL above 200 Hz still is 110 dB (with less than 3%THD)!
Why then the "trouble" with adding the sub? Because sub can deliver more than 110 dB clean (<3% THD) SPL below 100 Hz, instead of 100 dB without it (sub). Now, we have clean SPL = 110 dB for all frequency spectrum (including 100 Hz), instead of only 100 dB at 100Hz without the sub.

2. Let say Neumann have made passive “satellite” model "KH 150 PASSIVE" with the same drivers and enclosure from KH 150, but with passive crossover. We can connect this passive speaker to 1 kW amplifier, but no avail - again, maximum SPL above 200 Hz still is 110 dB irrelevant of the input wattage (from the 1 kW amplifier), because of the 3% THD limit of the loudspeaker drivers! We do want clean and undistorted sound, don’t we?
Of course, 1 kW can deliver higher dynamic SPL peaks (than KH 150 internal amplifiers) above 200 Hz – but with higher than 3% THD (coming from the speaker, not the amp)!

On-point, intelligible, and succinct. Thank you. Although the original conversation about this was with you, I was ambivalent about dragging you back in. Glad you jumped in.

What you explain here the second time is just as I had understood you in your original post. Hopefully this clarifies things for other users who keep repeating that crossing over lower frequencies would make the system louder. Now of course, adding a sub will make the total system louder, just like adding any other speaker would (but for lower frequencies). That was not the question.

If you don't mind, could you also address this premise that crossing over lower frequencies will somehow decrease the distortion of the speaker because it has to travel less? Because to me it sounds like loudness and distortion sort of go hand in hand. If crossing over lower frequencies could actually decrease the distortion of the speaker, then this would mean the speaker could now play louder to reach the same distortion level.

 

[ZolaIII]

@excelsius main point of high pass filter is to loosen the pressure on speakers. KH150 fals down sharp under 50 Hz but you cross it where it begins to struggle and that's 100 Hz and discard what port is producing, even better plug it.

 

[Galliardist]

I think a bit of perspective is needed here.

We have lots of posts from claiming that the system being purchased here won’t work because of this distortion and that SPL

I don’t know about most of you, but I spent around the same price, adjusted for inflation and different exchange rates, for my first system as a student in 1980. For my money I got a crude entry level turntable, a massive 25?watt receiver, a pair of basic speakers that went nowhere near 39Hz for -3dB, would have had far greater distortion, and a second hand pair of frame stands a few months later to replace a pair of old stools used to support the speakers. At that time I had a decent, large room as well, unlike today.

Whatever the shortcomings, consider the difference with what @excelsius has ordered. Now tell me that I didn’t discover and enjoy a huge range of music with my first setup after all because of all the problems I must have had.

Think back to your own first systems. How many were as good as this? And one upgrade, subs, will give a system in most ways better than anything available back then; definitely pre-CD.

And this fulfils a number of restrictive requirements into the bargain.

Take a moment to think of the scientists and engineers that make things like this possible, then carry on.

 

[excelsius]

It is not a simple question, especially since your use case is well outside the mainstream. To reiterate, no one attempts to listen as loud as you claim to want to with your size constraints, space constraints, and budget constraints. What you are attempting is not normal, therefore you will encounter little actual practical experience with that application.

The answer for most people in domestic situations is "good enough is good enough." This assumes passive speakers. Allow me to elaborate on the process using myself as an example.

My application is a combined home theater and listening room. Passive speakers are Revel F206, which are sized appropriately for the space and have an in-room F3 of 32Hz. My goals are to:

1. Extend in-room bass extension down to below 20Hz
2. Increase low bass SPL at least to THX reference level
3. Smooth bass response in the room (help with room modes)
4. Reduce distortion in the stereo pair.

Other criteria include at least two subs to fill in room nulls, and they must be small-ish.

I read objective reviews and settle on a pair of SVS SB-2000 12" sealed subs. They extend below 20Hz (meaningful bass will extend below 10Hz with boundary reinforcement) and are each capable of ~115dB at 30Hz according to CEA 2010 measurements, which is more than enough.

I take a day to carefully set them up via measurements: position, phase, crossover frequencies and slopes, levels, verify my results, and in the end, "good enough is good enough." The selection approach is hardly scientific, and the setup process is informed experimentation, AKA trial and error.

The result for critical listening is I can now push my stereo pair as loud as I want to without audible distortion--far louder than I can stand, and midbass clarity is improved because cone excursion of the 6.5" woofers is greatly reduced, as they are no longer trying to produce frequencies below ~70Hz.

^ The problem with the above result is that my speakers were not distortion-limited in the first place. Adding the sub made them cleaner, but I do not listen any louder, because I do not like to, which limits that benefit. My preference for loudness is high 70s to low 80s nominal, and that does not change because I technically can listen louder without distortion. I do not benefit from goal number 4 in real life. Bookshelf speakers benefit far more from this than towers.

Your situation is more complex using active speakers:

1. Active speakers are power-limited
2. Active speakers have protection circuits
3. No one does what you are trying to do with small actives.

Taking these one at a time...

1. No matter what you do with subs, actives always run up against power limitations. You will gain some SPL by high pass filtering the stereo pair, as the amps are less stressed by not having to attempt to drive low frequencies, but there are still limits. And, you cannot throw more power at them like you can with passives.

2. Similarly to the above, actives often have several protection circuits to protect the circuits and drivers. You cannot get around this.

3. The closest area of expertise I can think of to your application is a sound designer who sets up studio control rooms, mixing studios, mastering studios. But, they do not try to reach anywhere near your expected SPLs. They are designing for the high 70, low 80 nominal dB used by those engineers. They do not have criteria for damaging people's hearing. Further, those who mix and master classical music often use passive speakers with high power amps and/or huge active monitors. There is little to no precedent for your use case.

A few words on using subs to reduce distortion...

As has been stated in this thread, you can reduce woofer distortion in the stereo pair by high passing them and filling in the missing frequencies with subs. We are not terribly interested in low bass distortion, because we are not terribly sensitive to it. In a two-way speaker, this reduces midrange distortion, because the high pass filter reduces cone excursion of the driver responsible for bass and midrange up to the crossover frequency, and this is where the real benefit is. Distortion reduction is not limited to the sub / woofer crossover frequency; the benefit extends much higher than that. Things get even better with a three-way for obvious reasons.

TLDR:

1. The process is to find objective data and choose a sub that has the FR extension you desire, will play at the desired SPL, and has the distortion and compression characteristics you desire. Then carefully integrate it into your system, then measure the results.
2. Adding a sub DOES allow you to play music at higher SPL, but the benefit is limited in active speakers. If you want louder, you really need bigger amps and drivers.

Appreciate the explanation, but to clarify, we are simply talking about essentially the physics of a sound generation by the speaker. The speaker doesn't know if it's driven by an internal or external amp. Also, if the physics of the process are clear to someone, it should not matter whether the system is played loudly or not. The simple and key answer here is the CEA-2010 measurements, which Zollalll already referenced in an earlier post.

The irony of your request is that you have two objectives that may be mutually exclusive (1) highest fidelity, low distortion and (2) high SPL. For you to be able to distinguish the subtle distortions and differences at the bit level (assuming you can of course) requires you to listen at a volume below 80dB because at higher SPLs the loudness masks distortion you'd otherwise notice at 73dB (your hearing is protecting itself, attenuating for the volume) during critical listening. If you are planning to listen above 83dB, then focus on balanced/accurate bass retrieval by budgeting for a subwoofer or two (with necessary room EQ to flatten the peaks and valleys at your MLP) to match the required 90dB at 1Khz as others have noted above.

To your inquiry, there are no active monitors under $4K that will deliver the bass required for classical music at high volume output from 13ft away - HOWEVER if you increase your budget to $13K then I highly recommend the Dutch & Dutch 8C active studio monitors which will do everything you asked because it uses wall boundary and DSP to reinforce bass response and designed to do what you are asking.

I wouldn't call it mutually exclusive. With the new understanding of our perception of how speakers work, one can still listen at high SPL, but must realize that for bookshelves, there will be a cutoff. Mainly, depending on the specs of that speaker, beyond a certain SPL, the bass will start fading more and more into the background. If this is not an acceptable compromise, then subwoofers might be able to solve that situation before having to jump to a $10K+ system. As I'm getting a better understanding of the limitations, the choice of the KH-150 speakers make more sense to me.

 

[Spocko]

Appreciate the explanation, but to clarify, we are simply talking about essentially the physics of a sound generation by the speaker. The speaker doesn't know if it's driven by an internal or external amp. Also, if the physics of the process are clear to someone, it should not matter whether the system is played loudly or not. The simple and key answer here is the CEA-2010 measurements, which Zollalll already referenced in an earlier post.


I wouldn't call it mutually exclusive. With the new understanding of our perception of how speakers work, one can still listen at high SPL, but must realize that for bookshelves, there will be a cutoff. Mainly, depending on the specs of that speaker, beyond a certain SPL, the bass will start fading more and more into the background. If this is not an acceptable compromise, then subwoofers might be able to solve that situation before having to jump to a $10K+ system. As I'm getting a better understanding of the limitations, the choice of the KH-150 speakers make more sense to me.

Right on, subwoofers are the way to go if you have that option! KH150 are very good and state of the art as far as I'm concerned.

 

[excelsius]

Yes, three or four-way loudspeakers have less intermodulation or Doppler distortion, but OP asked for a good bookshelf loudspeaker. Bookshelf loudspeakers mostly come in a two-way format.


There is a widespread misconception that listening to music at particular SPL have to follow Flecher-Munson (or ISO 226:2003) curves. That is wrong!
Suppose we are listening to a solo piano recording, at the same moderate SPL=80 dB (average at mid frequencies) as in live concert at the fifth row. Should we boost low frequencies, say at 50 Hz, by +21 dB, to 101 dB - as the graph below indicates? Of course not - mic (recording) already had captured correct balance between low and mid frequencies (actually, piano key G1 has harmonics that are louder than 49 Hz fundamental!). That 21 dB boost (!!!) at 50 Hz will result in a catastrophic change in the timbre! The same applies to all low frequencies.

View attachment 275547

But what Fletcher-Munson curves are good for? For indication how much bass boost we should apply, when listening at much lower SPL than "normal". For example, listening the same piano recording at 60 dB, we should boost +12 dB at 50 Hz, to enjoy the same correct timbre. How we end up with this +12 dB boost? Simple - by comparing 80 phon and 60 phon equal loudness curves at 50 Hz: for 80 phon it is 101 dB at 50 Hz, and for 60 phon it is 89 dB at 50 Hz. The difference is 12 dB (101-89). Almost all "loudness" switches in amplifiers are boosting bass at around 15 dB.

Nice explanation. To confirm how well I understand (or don't understand) these curves:

• Let's say a composer has written a piece for a bassoon (50Hz+) and violin (200Hz+) duo--unrealistic, but simplistic for the concept illustration
• The composer would control how loud each of the instruments would have to play to match his intentions. This means if both instruments are to be heard equally, then the bassoon will already play let's say 20dB above the violin (or the violin will play quieter)
• A microphone recording this work captures it just like the human ear would hear it it, i.e., it's flat and you don't need EQ to hear the bassoon
• Now when this recording is played back on a 2 channel speaker, there will be no issues at all as long as the volume is kept below the highest bass SPL that the speaker can produce. So for example, KH-150 can produce 50Hz at about 100 dB (3% THD, black line in the graph below). This means that music would have to play at ~80 phons or lower to capture the full bass (see annotated graph below). In fact, no subwoofer is needed at this volume.
• But now if we raise the volume to lets say 100 phons, to truly hear the bass, that's when we would need a subwoofer to go up to 110 dB at 50Hz, otherwise the bass will start fading into the background (or become distorted, assuming you can hear that)
• Caveat 1: this still does not mean that you have to use a subwoofer at 100 phons because it would depend on the music. For example, even though that bassoon can go down to 50Hz, that frequency represents only the lowest note. The question then becomes does the composition even reach that lowest note and if it does, how often did the composer use the lowest notes? If during a 12 minute composition only a few of those 50 Hz notes are used, one would be missing barely anything in the composition than if a different instrument, like an organ, with heavy emphasis on the lower notes was used.
• Caveat 2: If someone is really trying to capture 20 Hz notes at a more "normal" listening level of 80 phones, the bass SPL required to reach those notes is almost 120dB. A quick look at the CEA-2010 sub ratings chart will tell you that the sub will cost around several thousand dollars to achieve such a feat. I would doubt that most people have $5K or $10K in subs to be able to truly capture all the bass needed even at normal listening levels. That's why an investment in a sub is definitely going to be always lacking and a matter of where you want to compromise. Also why having a sub will not necessarily make things sound better, depending on the music in question. This also further confirms the idea that a bookshelf + a decent sub is likely a much better way to go than towers alone. The room modes I read about also support this since they allow you to place the subs optimally.

At least that is my understanding.

 

[Newman]

The composer would control how loud each of the instruments would have to play to match his intentions. This means if both instruments are to be heard equally, then the bassoon will already play let's say 20dB above the violin (or the violin will play quieter)

If that was how music was made, then the frequency spectra of live music would follow the FM curve shape. It does not.

Like I said before, the music is what it is.

You are over-theorising and getting further from real needs.

 

[Galliardist]

If that was how music was made, then the frequency spectra of live music would follow the FM curve shape. It does not.

Like I said before, the music is what it is.

You are over-theorising and getting further from real needs.

Actually, part of the curve is sort of followed by orchestral recordings. There is always more output in the bass. Generally, mastering will then adapt the music to something closer to your own space.

It doesn't negate your point here though. Simply because the music already does what you need, you don't need to adapt that music further. You simply need the speakers to reproduce it. As I understand it, you need to work from the spectra of the music, not your hearing.

 

[Newman]

Yes, I have already pointed that out to the OP a couple of times, and like you say, it doesn’t negate the issue I raised with how the OP thinks live music is made.

 

[excelsius]

This discussion is exactly about speakers reproducing the music, as recorded. Assuming FM curves are correct, that automatically means that all that information is already encoded in the music for you to be able to hear it. It just becomes a matter of at which SPL can the speakers reproduce it. It's not about doing anything special to hear that music. I don't think we're in disagreement there.

@Newman, I don't quite follow when you say the frequency spectra doesn't follow the FM curve. Which spectra would that be? I don't think you can simply look at the average spectra output of a music piece and expect it to look like an FM curve. Music has an additional dimension of time. And even if you break it down and analyze any one instantaneous segment of time and chart freq vs SPL, it still does not mean that the shape will look like an FM curve. It would depend on what the artist was doing it that moment since music can have varying levels of bass to midtones depending on intention. That's why I simplified it to two musical instruments here. If you're in a room listening to a live performance, that should mean that if at any one moment the lowest note on the bassoon and the violin sound at equal volume to you at 80dB, then in that moment, the SPL of the bassoon must be 20dB higher than the violin. If that was not to be the case, then the FM curve would be inaccurate since that's the definition of that chart, as I understand it.

 

[Newman]

If you're in a room listening to a live performance, that should mean that if at any one moment the lowest note on the bassoon and the violin sound at equal volume to you at 80dB, then in that moment, the SPL of the bassoon must be 20dB higher than the violin.

Spot the inherent contradiction

 

[Newman]

Look, I know what you are trying to discuss and the, um, uniquely unreal assumptions you make in thinking your simplified examples are important. eg "the composer wants the two instruments at equal loudness", or "at a normal listening level of 80 phon and 20 Hz".

In reality your speakers are going to be playing recordings. 0 dBFS is it, the demands on speakers stop there. It all depends how far you turn the volume up. Once the midrange is about 85 dB average, we tend to lose interest in turning the volume up. It would be exceedingly rare for even a classical recording to have a peak to average RMS value of over 20 dB -- at any frequency -- so 105 dB is where the demands on the speakers stop.

 

[Newman]

the bass SPL required to reach those notes is almost 120dB. A quick look at the CEA-2010 sub ratings chart will tell you that the sub will cost around several thousand dollars to achieve such a feat.

Aren't those CEA-2010 ratings meant to be compensated to free space? In which case, add 6 dB to the sub's capability for floor placement in the centre of the room, another 6 dB for moving it to the middle of a wall on the floor, and another 6 dB for moving it into a corner. Then downrate that +18 dB to +12 dB for real room gain being less than theory. So a sub might only need to score 108 dB on the CEA-based chart to deliver 120 dB in a room.

But 120 dB was assumed by you off a chart based on an, um, uniquely unreal set of assumptions, see above. If we return to the 105 dB in my post above, and even allow an extra +10 dB for LFE effects (which is no longer a discussion of music), that's 115 dB. Less 12 dB for real room gain, so 103 dB.

And that's with one sub.

And that's for peaks. I don't think the CEA rating is for momentary peaks.

 

[Newman]

Bottom line. My post #73, now over 500 posts old, is still spot on. And yes, you will benefit from subs with your KH 150, just like I suggested with the bookshelves I suggested for a $3000 total loudspeaker system cost.

 

[Newman]

If this is not an acceptable compromise, then subwoofers might be able to solve that situation before having to jump to a $10K+ system.

If you ever decide to lift your budget to $10k, then heed this advice: put the extra money towards more channels.

Even allowing for less music being released on true MCH, even allowing for less-than-perfect upmixing of 2 channel material, the perceptual gains on offer far outweigh the gains you would get from spending $5k to make your system even flatter in FR than the KH150, or even higher SPL capability than the KH150 with sub.

 

[sejarzo]

If you're in a room listening to a live performance, that should mean that if at any one moment the lowest note on the bassoon and the violin sound at equal volume to you at 80dB, then in that moment, the SPL of the bassoon must be 20dB higher than the violin.

It would be more correct to say that if the a 50 Hz tone and one in the midrange are both perceived to be 80 phons (the proper unit of perceived loudness) then the measured SPL (a unit of actual energy) of the 50 Hz tone would be 20 dB higher than the SPL of the midrange tone.

 

[sejarzo]

If you ever decide to lift your budget to $10k, then heed this advice: put the extra money towards more channels.

Even allowing for less music being released on true MCH, even allowing for less-than-perfect upmixing of 2 channel material, the perceptual gains on offer far outweigh the gains you would get from spending $5k to make your system even flatter in FR than the KH150, or even higher SPL capability than the KH150 with sub.

Agreed. Even the original Dolby Pro Logic system made well-miked 2 ch orchestral music sound sound more realistic to me.

 

[JRS]

Great piece of information. But given the complexities (and room acoustics), it seems like +10dB for a sub compared to the speaker is a very rough approximation. For example, for 30 Hz, the graph shows the perception difference to be at +50dB, rather than +10dB. This makes it all the more curious that most manufacturers don't seem to publish any SPL data for their subs, much less Freq vs SPL charts. But if we assume that rule of of +10dB is accurate, Neumann's KH-750 sub which is designed to go with the KH-150 certainly doesn't conform to that rule since it has a lower SPL (even if one were to use 2 of them as you had mentioned before):
View attachment 275001


It's a mere discussion about the science of the speakers, which at least to me is interesting regardless of budget or even if I was not buying any speakers at all. The hobbies you mentioned can be much more expensive than this one. In the end, this is just another hobby based on personal preference.

There is or at least was a fairly thorough table of all the leading commercial subwoofers which tabulated max SPL's reached at two different frequencies along with cabinet size, efficiency and cost. Very useful, but unfortunately I can't seem to find it, perhaps someone here has a link. Also regarding the +10dB, I don't believe that was a suggestion to dial in the bass at +10dB relative to the midrange, but rather the sound energy required to hear something close to equal loudness is greater by a factor of 10dB. Dialing in +10 on top of room gain would result in a huge mismatch, as presumably the mastering of the recording has the proportions built into it and we want to reproduce that accurately. right. That many recordings tend to be dry is likely why a target curve is often tilted in favor of base, but typically a more modest few dB's with a few dB down at the treble extremes.

 

[Galliardist]

It would be more correct to say that if the a 50 Hz tone and one in the midrange are both perceived to be 80 phons (the proper unit of perceived loudness) then the measured SPL (a unit of actual energy) of the 50 Hz tone would be 20 dB higher than the SPL of the midrange tone.

For real instruments, though, that still isn't correct. The perceived loudness of an instrument also depends on the loudness of the harmonic output.

The more I read this, the more I'm finally getting a sense of what our old enemy Harry Pearson was saying, all those years ago.

 

[sejarzo]

Dialing in +10 on top of room gain would result in a huge mismatch, as presumably the mastering of the recording has the proportions built into it and we want to reproduce that accurately. right. That many recordings tend to be dry is likely why a target curve is often tilted in favor of base, but typically a more modest few dB's with a few dB down at the treble extremes.

I have seen more than a few comments here (meaning, not only on AV enthusiast forums where one might think it's about effects, not music) regarding how high some users typically set their sub gains that make me wonder if they were born with severely compromised hearing down in that range.