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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
herman
2,259 posts
 

The amplifier takes time to make this power (i.e., slew rate). So the amp "slews" 3.16 times faster to reach the same volume level resulting in increased dynamics for the high efficiency speaker.

that's not how it works, that is not how slew rate factors into how an amplifier works. Slew rate is directly related to bandwidth, not how quickly it reaches peak power operating within it's specified bandwidth. 

 an amp operating withing it's specifications that is  producing  100 W RMS at a given frequency will reach peak power in  the same amount of time as a 1 W RMS amp will.

Example.... at 1000 Hz the period is .001 seconds. So starting at zero crossing  it reaches a peak  .00025 sec later , crosses zero in the opposite direction at .0005 sec, the opposite peak at .00075 sec, and back to zero at .001... no matter how much power it is producing..  If it didn't it would be distorting the signal. 

 

normb's avatar
normb
174 posts
 

@danager 

Thanks for posting the link. 

mijostyn's avatar
mijostyn
8,570 posts
 

@herman Would that be in Denver or NYC?

Efficiency is not the issue, unless you have a silly pea watt amp. What you like to listen to is the issue and speakers, being the most difficult of all components, are always a compromise. I'll only listen to Line source dipoles. They are usually not very efficient. 

unreceivedogma's avatar
unreceivedogma
985 posts
 

I have been using for 39-46 years the following:

- Altec Lansing 604Cs: 101db efficiency, 26 ohms. 
- NYAL Julius Futterman OTL3 monoblocs, converted to triode, about 135 watts each. 
 

theaudioatticvinylsundays.com/about

toddalin's avatar
toddalin
282 posts
 

"an amp operating withing it’s specifications that is producing 100 W RMS at a given frequency will reach peak power in the same amount of time as a 1 W RMS amp will."

 

You missed the point. I said ALL OTHER THINGS BEING EQUAL. So the same amp, be it 1 watt or 100 watts, is used with both speakers.

Obviously a 100 watt amp will produce 1 watt (0.278 times the voltage) quicker than it will produce the full 100 watts.

Even a perfect square wave has a "rise time" and obviously it passes through 1 watt on the way to 100 watts.

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