Speaker sensitivity vs SQ

Hi ctsooner.

Others have said that higher sensitivity speakers have to be larger in order to transduce low frequencies at the correct levels.  Also that driver manufacturing tolerances are tighter.  Both these increase costs.

But if that's not correct then you must go back to my original post and tell me why all manufacturers don't build high sensitivity speakers, rather than only a small minority.

Guys, it's simply not true to make a statement that a higher sensitivity speaker is more costly to make.  Drivers, cabinet material, R&D, spikes, connectors, wire, glues, finishes.... and of course how many points dealers get to sell them

Let's be clear about one thing: Sensitivity isn't the same thing as Efficiency and it really is the latter which is the focus of this thread. You can build a high sensitivity speaker by simply taking a number of low efficiency drivers and putting them in parallel. Cheap and high sensitivity, but its efficiency will remain low. High Efficiency cannot be achieved cheaply for the simple fact that there is a much higher degree of precision needed in the construction of the driver's motor.

The difference between Sensitivity and Efficiency: The former is 2.83Volts at one meter. The latter is 1 watt 1 meter. If the speaker is 8 ohms the two are the same. If we take four 8 ohm drivers that are 87dB and put them in parallel, the load is now 2 ohms. The sensitivity is increased by 6dB; 93dB doesn't sound too bad. But that is 2.83volts into 2 ohms; when you do the math that is 4 watts. If you put 1 watt into that same array you'll still get 87dB. A higher efficiency driver that can make 98dB with 1 watt and is 8 ohms is a different beast altogether. This describes the 15" drivers in my speakers at home and they cost $2000.00 each.


You can find 15" drivers that cost $200.00. I'd be very interested to learn of a 15" with the same 22Hz free air resonance and 150 watt power handling that cost $200, or even $600.00. Have at it! But I think you'll find that such simply does not exist.

1+ ctsooner. The most expensive speakers I have even seen are not efficient at all. The Klipsch Horn is actually a good value in today's market.
@audiokinesis, That makes perfect sense Duke. The radiation of the woofer will narrow down to that of the horn buy 700 Hz. It should work as long as the driver is not colored. The speakers that I have heard that run a 15" woofer that high have been colored. Again the K horn is a good example and I think they moved the lower crossover to 350 Hz from 500 Hz. If you manage to avoid another crossover point that would be great.
@atmasphere, I do not disagree. Thermal compression exists but good drivers take this into account, ventilation, ferrofluid, etc. So, to what degree does this effect the sound we hear at home, at the volumes we listen at. The only drivers I have are subwoofers and with the system going as loud as I'll ever play it they are just loafing along. I would think ESLs would be more limited by mechanical compression than anything else. I'm not sure but I do not think they heat up at all. The transformers certainly stay cold. Transformer saturation might be an issue.

@audio2design, I doubt anyone is going to jamb a tube or class A amp into a speaker enclosure. You can add DSP control to any system. Check out DEQX and Trinnov. The problems with active loudspeakers are, audiophiles tend to shy away from all in one stuff. Right now this market is with equipment like Sonos. Great for TV and background music, not to hot for overall sound quality. The companies that make this stuff and have the horsepower to do it are not interested in audiophiles. Not enough of us. They are marketing to the masses who do not like big speakers, do not want to spend a gazillion dollars on equipment and are not critical listeners.  I also doubt they would ever go near an 8 foot ESL. Amar Bose was a brilliant guy but lets face it, the 901 was not a great speaker. He sold a bunch of them jumpstarting a huge company with lots of horsepower. Look what they make now. How is Meridian doing? You certainly do not see a lot of their systems in the US. Audiophiles have a tendency to be digital and processor phobic. The last thing a died in the wool Vinyl listener wants is a computer in his speaker.

@clearthinker --

I'd agree with poster @ctsooner here. Pro manufacturers, the more or less sole supplier for this segment, have developed and build their high efficiency drivers for decades now, and relative to their size, material use and R&D are actually very fairly priced compared to "hi-fi" drivers in general. Boutique high eff. drivers with AlNiCo magnets or field coils housed in luxuriously finished cabinets and all will always be (much) more steeply priced, though are hardly representative in this context. Fortunately they needn't be that pricy to show the merits of high efficiency designs. 

Largely it comes down to size, sound type and association, I believe; high efficiency speakers are closely related to if not directly derived from the pro sector (certainly driver-wise), a sector audiophilia isn't too comfortable with, and coupled with their sonic imprinting as typically more direct, dense, dynamic and present (also due to their dispersive nature) may not appeal to audiophiles and their more widespread exposure to a "softer," thinner, more laid-back and "reverberative" sound (some even feel the dynamics capabilities of high eff. speakers to be "exaggerated"). I'm sure many regard high eff. designs as more "brute" and lacking subtlety, not least when linked to the pro/studio environment, but it's often very far from the truth (did I mention conjecture?). As if sheer volume wasn't an issue already high eff. into the lower octaves takes some very serious size - there's no noodling around that requirement either - and when most have jumped ship with the high eff. main speakers long ago it's even more rare seeing subs in this category of speakers. 

What's most popular in hi-fi is also a popular narrative, and that's an inertia not easily brought to hold. 

@mijostyn ,

How can you cool the driver voice coil if you need 100 watts to listen to it at normal volume?
Even if you put a dedicated fan it wouldn't help!
In contrast if you need just 5 watt, you don't have this problem even with the most straightforward driver coil design.

Regards,
Alex.