What makes a speaker perform well at low volume?


A newbie question, for sure.

I have seen threads that attempt to identify speakers that are good that perform well at lower volumes. I am curious to hear what, if any, quantative attribute make a speaker perform well at lower volumes.

For instance, higher sensitivity? Higher/Lower impedence, etc?

Thanks.
matthew_s
A good amplifier is the biggest contributor, being able to manage the musical spectrum faithfully at low volume is not trivial.
My experience indicates that more efficient efficient speakers usually "perform well" i.e, deliver music and detail at lower volumes.
I agree that this is not a trivial issue, and certainly not a newbie one either.

I am in the camp the music sounds best within a narrow range of volume. This is most often very close or a few dbs louder than the recorded volume. I find that music that is excessively loud tends to become unrealistic. Whether this is due to room acoustics, speakers, amps, etc is open to debate (but please don't). It's probably a combination of all those factors. I suspect the room acoustics is likely a huge factor.

When music is too low, the instruments lack weight and palpability. The best example I can give is trying to convey the image of massed strings, like a violin section in a full orchestra. This is extremely difficult for a stereo to do, and I believe a speaker needs to move a critical amount of air to achieve this effect. At low volumes, it just doesn't sound like a full string section. I now have my stereo tweaked so that it does convey that elusive massed string effect, but it needs to be at least at a concert-going volume. My stereo can convey alot of detail at low volumes, but a good volume is important for having a connectedness with the performance.

I suspect that all this comes down to listening preferences, music preferences, stereo preferences, room acoustics, and the components as well. Good luck in your quest...I suspect you'll need it.
This is very important to classical music, as it is not usually very loud live. Next time you're at an orchestral performance, notice that you can easily hear someone's sniffling nose 5 seats away, or your own feet shuffling, on all but the loudest of crescendos. Most stereos have to be turned up much louder than the live orchestra to convey the same richness and excitement. If you can get involved with the music at low volume, you have a very special system indeed.
Excellent question, I wish I had the answer.
Well,

1st thing, study the Fletcher-Munson curve to help define how your hearing changes at varying dB's, then measure the average spl at which you listen to music. Look at the chart.

2nd realise that equalization is needed, whether the speaker has it subtley built in itself or something as coarse a loudness button on your amplifier.

All of the answers above to one small degree or another are correct but the true reality is a speaker that has boost in the highs and the bass will sound the best at low volumes period. Those speakers will achieve the nearest flat response to your ears relative to normal listening levels at lower listening levels.

A sensitive speaker and amplifier have little to do with the overall performance unless they address the F-M Curve in some fashion at the levels you are listening too. Address your hearing and background noise in the room and you will solve the problem of listening at low levels.

An decisive solution to your problem is the Accuphase DG-38. This will solve all your problems, at normal and low listening levels.
Honest1,

You are right about the volume difference in a concert hall vs. at home. I can easily whisper something to my wife at a concert, but she is always telling me to turn down the stereo because she can't talk to me.

This brings up an interesting question, of whether a stereo has the physical capability of conveying the type of dynamics of an orchestra. Of course, a stereo is a vastly simplified illusion, and is amazing the degree to which it approaches a real performace. However, consider that there are over 100 musicians on stage. Each musician has an instrument, often with multiple strings, each of which is vibrating independently. When you think about the 1000s of pieces of string, reed, skin, metal, and wood vibrating on the continuum of a stage, you realize that a stereo will always fall short. A full-range speaker will most often have only 8 points of vibration eminating from 2 points. Our mind is fooled even though the approximation can only be considered grotesque.

Also, a concert hall is very different than a living room. It is professionally designed and has space to allow the different vibrations to assimilate, reinforce one another, and disperse. How can one compete with that?

Rob
IME, the amp, the speaker and the cable all make a difference. Tube amps can sound excellent at low volumes, but I've heard a couple of SS amps that can too. Some speakers are better than others at low volume, more efficient speaker generally being better. My Tannoys were outstanding at low volumes maintaining life and presence, my AN E's less so which seem to lose life at very low volumes (and are actually efficient speakers at 94 db). But this last point I think could be related to the cable. I'm running 17 feet of speaker cable and something tells me that the long length of cable is not good for low volumes. I have not been able to try the E's on shorter cable.

Another good low volume pair was my JMR Trentes with the Resolution Audio s30 integrated amp. This amp is based on a DNM design which is noted for maintaining life at low volumes. Conversely, I had a Blue Circle amp that went dead at low volumes.
Three words: Low level detail. Sometimes the problem lies in the passive parts of your louspeakers (binding posts, wiring, crossovers, etc). sometimes it's the drivers themselves. Sometimes the problem is farther up the signal chain. And yes, high-efficiency/high-sensitivity speakers, especially single driver speakers, and well executed multidriver speakers are usually good in this regard. It also helps to have speakers that sound coherent (as cut from the same sonic cloth) over as much of the volume range as possible.

I don't have all of the answers. I've only been at this for less than 4 years.
Lack of hysteresis provides good performance at low volume. A speaker has to settle exactly at the same resting point every time there is "0" signal. Most do not and they "oilcan" to some extent. This muddies low volume inputs.
I was not able to "hear" everything at low volume until I replaced my pre-amp with a Tom Evans Vibe and Pulse. This suggests to me that every component may have something to do with this. Any weakness can possibly hamper the ability to play properly at a low volume.
First, a speaker must have excellent low-level resolution. This is primarily a power-to-weight ratio issue, so high efficiency speakers do well here (very powerful magnets), as do electrostats (ultralight weight diaphragms). The suspension system comes into play as well; some suspensions exhibit hysteresis (slow return to rest position) that can reduce low-level dynamic contrasts.

Next, a speaker must have fairly smooth midrange to sound good at low volume levels. At normal volume levels prominent bass can mask midrange peaks and resonances, but very low volume levels can unmask these anomalies. The ear's sensitivity is weighted more towards the midrange at low volume levels, so glitches in that region aren't going to be masked by the bass.

Then we want the tonal balance to remain correct at low volume levels. We'd like to think that the woofer and tweeter both get loud at exactly the same rate (3 dB for each doubling of input power), but in reality that's seldom the case. The vast majority of drivers exhibit power compression of some kind, with the result being that a doubling of input power gives a less than 3 dB increase in loudness, and conversely a halving of input power gives a less than 3 dB decrease in loudness. Typically woofers compress more than do tweeters, so if a two-way speaker is voiced to sound right at say 80 dB, then up at 100 dB it will sound bright (tweeter louder than woofer) and down at 60 dB it will sound dull (tweeter softer than woofer). Single-driver speakers inherently do a fine job of retaining their tonal balance at low power levels; unfortunately many single-driver speakers have a somewhat thin tonal balance that leaves the bass completely out of the presentation at low levels.

Finally, at low volume levels good dynamic contrast is especially important, as we must rely on dynamic contrast to breathe liveliness into the sound because by definition we can't do it with impact. Dynamic contrast (lack of power compression) generally correlates very well with efficiency; in other words more efficient speakers are likely to have better dynamic contrast at low volume levels. The crossover seems to play a role here as well; this may be overgeneralizing, but crossoverless or simple-crossover speakers seem to me more likely to sound good at low volume levels.

Speakers that sound especially good at low volume levels include models from Quad (especially their original ESL, the "57"), Omega, Cain & Cain, Classic Audio Reproductions, Sound Lab, and Edgarhorn. These are all either high efficiency horn or single-driver speakers, or full-range electrostatics. Disclaimer - I peddle some of these. No doubt there are other speakers that sound quite good at low volume levels, but I'm just mentioning these as examples that I'm fairly familiar with.

In my opinion, if a speaker sounds good at very low volume levels, that's an excellent predictor of long-term fatigue-free enjoyment. I recommend that people listen at very low volume levels at some point in their auditioning process, because this will reveal a lot about a loudspeaker that can otherwise be overlooked in the excitement of how good they sound when cranked up. In particular, listening at low volume levels will reveal how good the low-level detail is, and that's often what separates the great speakers from the good ones. Also, midrange problems are often more easily highlighted at low volume levels. And if the speaker's tonal character changes markedly when you turn the volume way down, chances are it also changes markedly when a very loud peak comes along.

If I ever bring out a loudspeaker of my own, sounding good at very low volume levels will be a high priority.

Duke
All speakers change "Q" ( tuning ) as they are driven at different levels. As such, they all have a specific point where they will operate most linearly. The problem with a multi-way design is that it is possible for each of the drivers used to experience their "optimum Q" after warm-up in different spl regions. The end result is a lack of cohesivity unless one can find an SPL that presents a happy medium to all of the drivers simultaneously. Most of the time, this won't be at a low listening level either.

Now factor in that all ported / bass reflex designs are subject to variations in the flow velocity of air within the vent as SPL is varied. Unless a vent uses a gentle radiused flare at both the inlet and outlet side, the bass tuning will be optimized over a very narrow SPL range. Once again, if one is trying to listen outside of that range and / or in a range where the other drivers aren't hitting their stride in sequence, the end result is less cohesive sound. In this regards, sealed designs are more linear over a MUCH wider spl range and retain a higher percentage of "bass weight" as spl's are reduced.

As such, it is easy to see why / how speakers using one dynamic driver ( Walsh's / Lowther's / Fostex, etc ) and / or full range planar / E'stat type speakers excell at low volumes. That is, there's only one driver or type of driver to excite and all of the operating characteristics will remain consistent over the entire band. In effect, the speaker is more uniform in its' presentation, regardless of spl range. There is no "confusion" as to when each of the drivers is working optimally as they are all working in unison sharing the same load and electrical characteristics. On a dynamic multi-way system, each driver has individual electrical characteristics and they are VERY different from one another. If they weren't, there wouldn't be a difference between a woofer, a tweeter and a mid.

On top of that, many of these designs, especially E'stat's and Planar's, have very considerable surface area to radiate signal from. Even though one is not moving a lot of air due to a lack of excursion, spreading the sound that is being radiated out over a larger surface tends to present a slightly different tonal and transient presentation to our ears and brain due to the way that it excites the room. The fact that ambience cues remain more consistent with omni & dipolar radiators regardless of spl range also factors in too.

Outside of that, you also have to consider the noise floor of the electronics, how linear they are at low power levels, etc... Most high powered amps don't do all that well at very low power levels, hence the move to lower powered levels and / or higher bias Class A or richer Class AB designs. SET amps are a "double blessing" in that regards as most are both lower powered and Class A biased. The reason that the higher powered amps don't do well is that they make use of a multitude of output devices, which typically aren't matched all that well. At low levels, they are all doing their own thing and it isn't quite in perfect unison. It is not until the drive levels are increased that they begin to work as a team and everything begins to fall into place. The end result is that there is greater "slack" or "tolerance" in the circuit at lower levels, resulting in poorer, less cohesive sound.

As such, there are many factors that add up to "good sound" at low listening levels. If one is going to do a LOT of listening like this, one might want to build their system specifically for this purpose. It is tough to achieve stellar performance levels at both high and low spl levels with good extension and it typically takes a LOT of money to do so. Factoring in realistic expectations as you build your system may make for both a more enjoyable and less costly experience than having to change everything as you find out your listening habits aren't quite as "wild" or "mild" as one originally thought.

As a side note, one of the things that i like most about my Ohm's was the fact that i could listen at low spl's and still achieve staggering bass extension out of this design. It is the only speaker that i know of that can shake the floor at very low spl's. Then again, in stock form, this speaker is not capable of high spl's with good linearity, so it is somewhat of a specialized speaker. As i mentioned above though, i took this factor into consideration when building the system that i use them in. That system is right in the same room as my computer, where i do a lot of late night, low volume listening. The fact that the amps driving them run in Class A up to 50 wpc with 800 wpc at actual impedance of the Ohm's ) assures both high levels of linearity with an iron fist in terms of control : ) Sean
>

PS... These speakers are about 82 dB's and present a nominal 2-3 ohm load to the amp. NOT an easy speaker to drive and many amps aren't up to the task, even though their power ratings say they should be.

Currently listening to Cake: Pressure Chief on Redbook CD
Everyone - thanks so much for the time and effort. This has been very educational for me. Searching the internet (and suprisingly - especially this site, which at first, I thought was only about selling used stuff) has opened my eyes to a lot of options I did not know existed.

This all started with thinking about getting decent monitors to act as my primary music and TV sound source (and maybe building out a 5.1 system).

I have been thinking a lot more about what I value (i.e. - I know I won't critically listen to movies, only music; I won't have many opportunities to run the system "wide open") has then directed me to stay in the 2 channel world, and consider tube power. Then, just last night I stumble over information about single driver speakers (hornshoppe is one that caught my attention via some threads elsewhere). So many options.

It is not clear to me if horn-loaded single driver speakers are really feasible though. These won't be in a dedicated listening room (i.e. - can't get 100% choice in placement) - so it is not clear if these would work for me. I hope I can find some place around here (central jersey) to have a listen. I all liklihood, I will need to keep looking at monitors.

I digress. There is an amazing range of choice out there. I am facinated by the information and options out there.

Thanks,

Matt.
Be especially careful when demoing horn-loaded speakers. They are usually dynamic and may sound exciting at first but many horn owners complain of listener fatigue over time due to their "in your face" response.

You need a speaker that doesn't shout and produces what is on the recording, nothing more, nothing less. And be careful with true studio monitors, they are usually uncolored and very revealing but don't have the mid range magic our ears enjoy over the long term.
As a single-driver speaker user, I can tell you that this is a very careful path to walk, if you want to really get what they are capable of. The entire system needs to be of a caliber that will work best with these types of speakers.

Basically, you need a low power SET amp of high quality to drive the single-drivers. The reasons are complex, but basically that's what works best. Most single-driver speakers are very efficient(especially any horns), and they are very detailed and revealing. This means that the whole system needs to be almost free of any noise or any synergy problems. High power amps are not needed, because the speakers will play loud with only a few watts. Go for the purity and coherence of a good quality SET amp with that kind of speaker(which accentuates the purity and coherence itself, and is one of the main reasons for single-drivers).

Personally, I experimented with the smaller Fostex drivers like are used in the Hornshoppes, and found that they lacked the surface area needed to get reasonable SPL in my room. I eventually found my needs were filled by Lowther 8" single drivers. They play quite loud on a few watts, and sounded much better than the Fostex to me.

With single-drivers, the pathway is very narrow, if you want to get the best from them. But, the rewards are very good, for the strengths that come from a system like this.

Beware, that very low bass is not a strong point of systems like this. But, the sound that you do get, from about 40-60Hz(depending on speaker) and up, is very very nice.

My advice is to use a larger driver of around 8" diameter, instead of the small drivers in the Hornshoppe. Also, using rear-loaded horn enclosures(like Hornshoppe style),or Voigt Pipe, and avoiding front-loaded horn designs, will keep the sound from being too colored and "in your face" like some front horn designs can be. Real high-end front horns can be very good, but in the budget range, I'd avoid them.

Try to avoid solid-state amplification when using speakers like this. The advantages of SS are not useful with this type of speaker, and the disadvantages are clearly heard.
I think Cinematic_systems is right on!!!

He gets my vote for Post Of The Year.

I almost NEVER hear audiophiles discuss the Fletcher - Munson Curve, and it is why I feel just about all systems have nothing for me at lower volumes. I don't feel the music comes alive until about 85 dB. Below that, the frequency response of a system is all out of kilter. People eschew the use of loudness and tone controls, but I just about never hear music sound as it should through an audio rig at 70 dB.

Bravo, Cinematic_systems!
Thanks for the comments Trelja,

This thread was beginning to worry me, I was getting the feeling that this was a complicated problem LOL! With only mythical and very expensive solutions.

I can't believe all the gyrations people think they need to go through to solve a simple problem. :)

"Root Canal Audio" is a phrase a friend turned describing most of what is written above.

thank again T