How important is the efficiency of a speaker to you?

I went to an audio meeting recently and heard a couple of good sounding speakers. These speakers were not inexpensive and were well built. Problem is that they also require a very large ss amp upstream to drive them. Something that can push a lot of current, which pretty much rules out most low-mid ( maybe even high) powered tube amps. When I mentioned this to the person doing the demo, i was basically belittled, as he felt that the efficiency of a speaker is pretty much irrelevant ( well he would, as he is trying to sell these speakers). The speaker line is fairly well known to drop down to a very low impedance level in the bass regions. This requires an amp that is going to be $$$, as it has to not be bothered by the lowest impedances.

Personally, if I cannot make a speaker work with most tube amps on the market, or am forced to dig deeply into the pocketbook to own a huge ss amp upstream, this is a MAJOR negative to me with regards to the speaker in question ( whichever speaker that may be). So much so, that I will not entertain this design, regardless of SQ.

Your thoughts?






There has been this old adage of tube watts being more powerful than solid state watts. For most of the last fifty years I used mammoth high powered solid state amps. Then about five years ago switched to Audio Research Reference amps 160m monoblocks and 160s. I run the 160s in triode mode… so only 70wpc and they are ferociously relaxed and powerful, absolutely no lack of muscle… but they don’t flaunt it… it is just there, rock solid at any volume.


I also have a friend with a pair of Wilson Puppies and an Audio Research VT80. They drive the Wilson’s to incredible loudness without any sign of running out of power or dynamics, rock solid. I really cranked them last weekend.

While I haven’t recently tried to put 70wpc tube power up against solid state but I am pretty sure it will stand up against two or more times the SS watts. So, I had figured the old adage of the difference between tune and SS was really subtle. It isn’t and still seems to be there..

Ok I have Polk lsim707 ,88 db and thery are driven with a Caryin XL 55 tube amp light 20 wpc and they sound great....there in a very large room with cathedral ceilings....i was,told owe you can't drive them with that tube need 300 wpc.....well they were wrong ,totally. I have used these hook up for 2 problems at all....

I think many of the values discussed here and elsewhere assigned to high efficiency speakers are not accurate. First the entire discussion of what is delivering the improved efficiency is not differentiated- is it drivers or how the driver is used that gets you better efficiency? These two ideas.make a huge difference in performance but are distinctly different methods of achieving improved efficiency with their own costs, benefits and penalties..

Example 1: a lower efficient driver can be made more efficient by placing it on a horn, which complete changes other characteristics/parameters of performance and behavior. An acoustic suspension system or a horn system are very different from each other in many ways having a direct impact on performance.

Example 2: You can build a more efficient driver by lowering the mass of its moving parts. Lowering this mass can cause multiple things to happen, typically increasing ring modes and distortion. Here efficency makes the driver sound worse. Another outcome of lowered mass is poorer low frequency performance.

Example 3 Higher efficiency drivers do not always offer lower power compression. If you use titanium instead of aluminum for your former, the thermal resistance is far higher with titanum than aluminum, so heat can’t escape the lower mass system increasing thermal power compression. Higher efficiency increases thermal power compression in this case. DO you know what your VC former material in the speaker system you buy actually is? Thermal power compression is affected by a long list of factors that are far too detailed and complex to discuss here or ina spec sheet: issues such as VC impendance, VC material, front plate/pole piece proximity to coil, airflow and venting of the magnet system. Looking at a efficiency measurement and assessing quality is like looking at frequency response and assessing sound quality- it really isn’t an indicator of performance in a way that is simple or easy to [universally] understand.

I know poeple really want there to be a simple way of looking at things but this is some deep science. A speaker involves practicaly all the sciences and there is no way to simplfiy it and express that in a spec- unless you are willing to bullshit or tell a helluva convincing marketing story. Most do exactly that, but its a diservice to the thinking person’s aims in a playback system.

If you love the idea of a flea watt amp, you are sorta stuck with high efficiency loudspeakers to have any hope of dynamic range. If you are more open minded and are wiling to look at moderate efficiency speakers in the mid 80s, using the wide array of excellent high power amplifiers available, or active speaker configurations, you can have your low distortion, wide dynamic range AND better bass AND wider dispersion, etc, etc. But you cannot have all that AND super high efficiency.

I think we are back to listening to a speaker with a proposed amplifer and assessing if this combination works for you and addresses the things you care about.



You can also make a more efficient speaker by "tightening up the tolerances" (i.e., tighter fitting voice coil/gap) and increasing the number of windings within the same area (e.g., using flat-wound wire), without causing other problems.

BTW, a lighter cone will also allow the driver to play to a higher frequency without break-up.

My "Merman" speakers are extremely efficient, and sensitive, without horns, and can easily do "live concert levels" and I wouldn’t have it any other way.

Remember that the volume control is nothing more than a "focus knob" and sometimes you really need that volume to bring the cut into focus.

Also, I feel that an "immersive experience" takes realistic volumes to achieve.  You can't immerse yourself in a tub of water if it only covers your toes. 

If you want/like 8 ohm 86 dB sensitivity speakers you will most likely have to go with a high watt output solid state amp (>150 watts). 

It takes 150 wpc plus (ss) to drive a speaker rated at 86 db?