What is your take on high efficient speakers vs. low efficient speakers?

@larryi wrote:

Thank you for an excellent description of what is most prized about the sound of high efficiency systems, particularly, horn-based systems.

Glad you found it worthwhile.

While good design of such systems will ameliorate midrange "peaky" or "nasal" colorations, such systems do tend to be a bit less smooth in frequency response than better low-efficiency direct radiating speakers. I hesitate to say this because so many people have heard grossly uneven horn and wide range high efficiency driver systems, and do associate such systems with such coloration, but I will say that such problems can be effectively ameliorated in better designs. Still, I can see why such systems will not be to everyone’s taste.

Smoothness, or lack thereof in frequency response can definitely be a factor, I agree. Great horns don’t really sound like horns (if there even is a decided consensus about what horns in general sound like, and with the implicit notion here perhaps that "horn sound" has a more or less distinct character), and the bigger they are even less so, I find. Yet, large and great horns definitely don’t sound like smaller, low efficiency direct speakers either, but are in some respects more reminiscent of very large panel speakers. Indeed I would go so far to claim that some don’t like horn sound just by virtue of it sounding different compared to low. eff. direct radiating speakers, even if the former are devoid of uneven frequency response or colorations in general.

@audiokinesis wrote:

Very often the limiting factor for high-efficiency systems is the on-axis frequency response at high frequencies. And one way to get very high efficiency numbers is to use a horn whose pattern at high frequencies is very narrow, such that all of the high frequency energy is concentrated in a narrow beam, thereby maximizing the on-axis sound pressure. If the same compression driver were used on a wide-pattern horn, the same amount of acoustic energy would come out, but because it’s spread over a wider angle the on-axis PRESSURE would be less.

The EV Constant Directivity horns (HP9040 + DH1A) on my EV main speakers, by virtue of not narrowing the HF response on-axis, should require equalization in its upper band above some 3kHz, at least for their intended cinema use, but surprisingly we’ve only found it necessary and most important to apply some notches and a peak suppression via a Xilica DSP (active config.). This ameliorated a slightly can-ey and mechanical imprinting for a very smooth upper band reproduction. The lack of a need for an EQ gain-boost in the upper octaves I’m guessing may have to do with the limited spacings they’re now used in vs. large auditoriums, with the former providing some boundary gain. What’s your assessment here?

Some horns have coloration, which imo eliminates them from serious contention. At the risk of over-generalizing, I’d be wary of horns which have sharp-edged internal "kinks" and/or sharp edges around the mouth.

The EV horns of mine both have a diffraction slot and sharp edges at the mouth area, and so may set the alarms ringing in many a horn-audiophiles’ head, but they actually sound very smooth after being properly implemented with mentioned DSP filter-actions above.

What’s less discussed or acknowledged even is the importance of horn size and its sonic implications. This is also a factor determined by the compression driver used here, with the very powerful DH1A being more properly loaded with the HP9040 horn compared to the smaller HP940 sibling (which I used previously). The DH1A simply seemed to "shoot through" the smaller HP940, but the sonic outcome also had to do with the horn resonance being placed higher in the upper mids on the HP940 vs. in the lower mids on the HP9040.

In any case a larger horn appears to fold-out the sound much more effectively for a more relaxed imprinting than a smaller horn, while also sounding more fully developed physically. Things being equal a smaller horn sports the more intensely "directed" sound (to many perceived as a horn-sound characteristic?), and the larger ditto has a much larger, even a huge and more relaxed sphere or bubble of sound.

I know horn geometry and diffraction eradication found in newer horns is very important sonically, but you come a long way with blunt, physical size in older more industrial (and still very well developed) designs, I find. Size is less sellable, though, and many don’t like the mere association with pro segment products.

Thanks for your great contributions, Duke.

@johnk --

Well put.

@johnnycamp5 , Then I guess you need more experience and I am not trying to be harsh. I really mean it. I went through life as an inexperience audiophile for decades. Then I got involved in the business directly and was exposed to hundreds of systems and I was responsible for designing at least 50 of them, all very high end for the time. I am also extremely inquisitive and structured. I AB equipment all the time and have learned to divorce my imagination from the process.

It is also quite possible to make the finest systems sound terrible. Very few of us have actually listened to a SOTA system and do not know how much performance is available and what it sounds like. 

@wolf_garcia 

I believe some horn speakers built today have gotten much better at imaging than horn speakers of the past, but if you're a fan of imaging, there are still a lot of horn speakers that don't image real well. I for one am a big fan of imaging and that is why I own Maggie 20.1s. Speaking of Maggies, which in my opinion should always be paired with a sub, can you imagine how little bass they would produce if they were high efficiency? Although there may be some planar speakers that are high efficiency, I can't think of any off the top of my head.

@mijostyn that is interesting…it’s the polar opposite of my experience 

@johnnycamp5 

This is the beauty of open discussion forums,  a broad expression of numerous listening experiences from a diverse group of music lovers/audiophiles. I’ve had the fortune of hearing quite a few electrostatic speaker based audio systems. Some were quite good.

however, if given a choice between that type of system compared to a high quality higher efficient speaker driven by good quality low power tubes, I’ll choose the latter every time. It is not a proclamation, my ears and taste  are not superior to another’s. It is just simply after many years and much exposure to various systems, I just know what suits me best and sounds best to me.

On the other hand I can easily understand why electrostatic speakers and big transistor amplifiers would have enormous appeal to another listener. This is an extremely personal endeavor without question. The vast spectrum of choice in High End audio is precisely what makes it so special.

Charles

@phusis wrote:

"The EV Constant Directivity horns (HP9040 + DH1A) on my EV main speakers, by virtue of not narrowing the HF response on-axis, should require equalization in its upper band above some 3kHz, at least for their intended cinema use, but surprisingly we’ve only found it necessary and most important to apply some notches and a peak suppression via a Xilica DSP (active config.)... What’s your assessment here?

The short answer is, I don’t know.

Perhaps the crossover filtering is providing the equalization without obviously using a dedicated EQ circuit, by cutting the lows instead of boosting the highs. Perhaps EQ is being applied somewhere without you knowing about it. Perhaps your compression drivers have signifcantly better frequency response than the published curve; I have found that to sometimes be the case, the manufacturer apparently having made unannounced improvements in the frequency response... but usually not to that extent. I don’t see an impedance curve online, perhaps there is an amplifier interaction with the impedance curve which results in a rising top end with your amp, or which resulted in a drooping top-end when the published curve was measured.

That being said, the published unequalized curve for that horn/compression driver combination looks right to me. It looks like the curves I get with large-format compression drivers on constant-directivity horns.

All of the above speculative explanations are unlikely, perhaps even highly unlikely, which brings me back around to "I don’t know".

Sorry about that!

Duke