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?

128x128daveyf

@rauliruegas wrote:

Well , that large size is not exactly typically " because depends on the kind of drivers other than horns and an example are my ADS speakers that yes are " large size " but the size is due that the speakers can goes down to 16hz through two 14" acoustic suspension woofers but today I have the ADS from around 100 hz and up and the soft domes ( silk ) acoustic suspension 2" for the mid-range and 1" for the tweeter ( one a top the other:nearest as it can be. ) needs a very small " box space " due to its very high gauss magnets ( are not vented and non-ferrofluid. ) around 24k in the tweeters and 18K in the mid range, both drivers made it in Germany for ADS and its efficiency is 95db ( almost a horn . ). Unfortunatelly the drivers manufacturer just does not exist any more.

True 95dB sensitivity is certainly quite efficient compared to the general norm of speakers (that are closer to a typical 85dB’s, making for a ~10dB difference here), and in conjunction with your ADS L-2030 speakers extending as low as they do with dual 14" woofers per cab there’s no escaping the implications specified by one Mr. Hofmann and the following larger size.

My efficiency context is higher, and once horn-loading becomes necessary/preferred, not least when you want them to act like horns in their entire frequency span, up to very large size is unavoidable. In my setup context I’ve not yet fully exploited the efficiency factor (save for the midrange/tweeter horn); if I wanted at least ~105dB sensitivity top to bottom (i.e.: 20Hz-ish on up) it would require non-truncated front loaded horn subs and similar type horns for mid bass (but with the fewest and low degree horn path bends) or star quad 15" direct radiators, which is a significant upgrade size-wise below ~500Hz easily by a factor of 2 compared to what I have now. Having said that my corner mounted tapped horns subs takes further advantage of significant boundary gain (1/8 space), and so the least efficient driver section is the midbass bins sitting at ~98dB’s (hardly slouches, also considering they’re high-passed).

Trying to make some sense of the madness one could ask whether an efficiency that high is really necessary in a home environment. Obviously that’s up for each to assess and decide, but to me at least it isn’t about bonkers SPL’s; it’s about maxing out the sonic potential of horns and aiding the best integration, also with direct radiating sections. Ease of load of the amps, not least with active config., is another boon. Indeed sufficient headroom is a prime takeaway here (regarding both speakers and amps) - that is, it’s that it actually matters, and far more than people seem to realize.

What keeps most audiophiles (who’re already inclined towards high eff.) from venturing into very high efficiency and directivity control in the entire audio band - with all that entails - is mostly about large size becoming an obstacle, be that aesthetically or practically. However it’s also about a particular mindset, because it requires of one to acquire pro segment, DIY or vintage gear when such large designs are hardly available domestically, not least at less than astronomical prices. It’s a radicality of approach few (but perhaps more and more) are willing to pursue.

Kudos on your setup, btw.

@deep_333 wrote:

Generally, high efficiency speakers have sounded unrealistic. What do the masses think of and come to conclusions when they’re thinking high efficiency? There it is, it can be attributed largely to bad actors like Klipsch, who’re all over the place and generally made plenty of flawed speakers with a couple of exceptions perhaps. It also seems like any other jester will come up with some horn speaker whilst tinkering in his garage, bring it to shows, etc and they’ve sounded stupid.

Nevertheless, when you buy a high efficiency speaker from guys who really know what they are doing, they seem to sound truthful. ...

I agree.

@lonemountain wrote:

Very good point and great example that there is more to know about a speaker than a 1w/1m spec. Could a 86dB 1w/1m speaker with a very flat impenace curve outperform a 91db 1w/1m speaker with a wildy changing impedance curve? Yes.

That’s not really saying anything about the argument of high efficiency, in fact it goes without saying. Your effort to isolate a high sensitivity rating as a singular, non-determinant factor in no other context than itself is just trying to serve an argument against it, and not seeing it for what it can do in the greater scheme of things. Come on :)

Over the years I have found that lower power amps (35-45 wpc) always sound better to my ears. That makes low efficiency speakers (83-87db) a non starter for me

 

Well, D.Wilson ( paw, unfortunatelly. ) was not so stupid and " deaf " as his national manager and he used only Krell/Spectral amplifiers with the Watt/WAMM speakers to monitoring all his great Wilson Audio recordings.

 

"

The manual suggests that direct-coupled Futterman and similar tubed amplifiers are inappropriate, but gives the OK for other tube models when used on their 4 ohm tap. I have to disagree. A 1 ohm load severely limits the output power from a tube amplifier. For example, a 100W output (17dBW, 8 ohm) into a 4 ohm load will typically fall to 7dBW, or 10W in level terms, when faced with 1 ohm. Simply, this means that the amplifier will clip 10dB earlier if a strong musical signal appears at 2kHz, which is not unlikely, since this frequency is well in the main music power band.

Let us also assume a typical case where the tube output impedance and cable loop are limited to 0.4 ohms. Overall there is a loss of 0.8dB over the whole range, but at the 2kHz minimum impedance the loss increases to nearly 3dB, this inducing a dip in acoustic frequency response of 2.2dB which may well alter the sound of the speaker.........................................................Last and by no means least, there is the matter of that awkward load impedance, and the corresponding, almost unforgivable dip to 0.33 ohms noted on the review pair.......................................................Depending on the amplifier used, there was also a touch of hardness on, or edge in, the upper midrange which was ameliorated by using the Goldmund Mimesis 3 power amplifier and one or two of the other high-current amplifier types such as the Krell. This mid-treble problem was rather amplifier-dependent (due to the impedance characteristic...."

 

Btw, we have to remember that that 1 0hm and 0.32 ohm at those frequencies is not a discrete impedance value but part of the speaker impedance curve and  the adjacent frequencies and developed harmonics are " touched " too.

 

Stupid people are all over the world and just fine with me.

 

R.

@phusis

My argument is that this efficiency as it relates to speaker performance is a complex issue, much more than a simple number. You forget I am engaged with dealers and end users who ask these questions (and similar ones) quite often. The desire to reduce a complex issue down to a simple one is very attractive when the subject is complex. THAT is my point, not that there aren’t times when facts are facts.

Since you own DH1A, I can use a historical reference: I bet you remember many people arguing the advantage of 1.3 inch throat driver/horns (EV) vs 2 inch driver/horns (JBL) and vice versa. That discussion was often reduced to focus on one attribute (throat diameter) when really it was a far more complex issue than that, depending on what you were trying to accomplish.

Brad

 

Dear @phusis  : " Indeed sufficient headroom is a prime takeaway here (regarding both speakers and amps) - that is, it’s that it actually matters, and far more than people seem to realize. "

Normally audiophiles do not cares enough about " headroom " eve3n some of them not even know what it means in electronics and especially when we are talking of speaker/amp combinations.

As  a fact I learned through my first hand audio experiences when I owned thr Classé DR3-VHC This amp is a pure Class A design with a power of " only " 25 watts but in its times was only one of the few amps that handled with aplomb the Apogee Scintilla that gone even lower than 1 ohm impedance and with not high efficiency but around  79db at 3m. but ( if I remember the Classé came with 7db on headroom and from here its VHC denomination: very high current. ).

 

R.