Sub resist load for speaker?

I read in sci.electronics.design that Pooh Bear wrote (in ) about 'Sub resist load for speaker?', on Thu, 6 Oct 2005:

Depends what you mean by 'top notch'. 'Top cost', yes; the conspicuous consumption bug is alive and well in professional audio as well as in the audiophool sector.

103 dB/1 W/ 1 m and at least a 500 W amplifier.

Yes.

--
Regards, John Woodgate, OOO - Own Opinions Only.
If everything has been designed, a god designed evolution by natural selection.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk

Having a larger box lets you use a higher efficiency driver. Driver efficiency is constant.

greg

[...]

There's a reason for that: Box size. There's a relationship between efficiency and box size for a given transfer function.

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http://www.flexusergroup.com/

I think its a poor choice for midrange, unless you like beaming effects.

For wide dispersion I prefer two to four stacked mids, not more than 5 inches dia.

greg

I've actually had 102dB sensitivity out of quite modest 10 inch units from Eminence ( ideal for midrange ).

Graham

Do please elaborate !

Graham

Speaker efficiency remains the same for SM boxes, determined only by driver efficiency. Changes in bandwidth may appear to make changes in efficiency. Horn enclosures can obviously change speaker efficiency and SPL. For all these explanations, do a GOOGLE groups search, driver efficiency pierce box size

greg

I read in sci.electronics.design that Pooh Bear wrote (in ) about 'Sub resist load for speaker?', on Thu, 6 Oct 2005:

Ah, yes. Eminence short-coil designs. Did you look at the third-harmonic? Actually, what is more instructive is to apply a sine wave, put a sound-level meter in front (set to 'linear' or 'C-weighting', and securely anchored down, of course!) and look at the waveform from the 'recorder output' if it has one.

A 10 inch is far too directional for a midrange. Unless you turn it off above about 1.5 kHz.

--
Regards, John Woodgate, OOO - Own Opinions Only.
If everything has been designed, a god designed evolution by natural selection.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk

"John Woodgate" Graham Stevenson

** The marketing folk at ElectroVoice will not be amused ....

.......... Phil

You're clearly not familar with typical SR practice.

12" units are often used for mid range very satisfactorily - not to mention the idiotic use of 15" units with a 1" compression driver crossed over @ 3-4kHz.

Bear in mind that some directionality is beneficial for SR use.

Graham

dia.

You won't get much volume out of them for a PA !

PAs don't want wide dispersion either.

Graham

efficiency.

can

GOOGLE

By 'speaker efficiency' do you mean the efficiency of radiation from a cone ? That's not what I would call industry standard parlance.

Graham

""Bjarne Bäckström""

** What ever that is - it certainly does not apply to any electrostatic speakers, ribbon speakers, flat panel speakers mid range domes or dome tweeters.

Funny how they all have pretty much the same acoustic conversion ratio of

85 to 92 dB SPL per watt / metre with no boxes in sight.

......... Phil

"GregS"

** Looks like a nice non sequitur.

............. Phil

I read in sci.electronics.design that Pooh Bear wrote (in ) about 'Sub resist load for speaker?', on Thu, 6 Oct 2005:

I'm quite familiar with SR practice AND its defects.

--
Regards, John Woodgate, OOO - Own Opinions Only.
If everything has been designed, a god designed evolution by natural selection.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk

I read in sci.electronics.design that Pooh Bear wrote (in ) about 'Sub resist load for speaker?', on Thu, 6 Oct 2005:

Incredible!

Which planet are you on? There are requirements for loudspeakers with every conceivable directional response, and some that aren't conceivable as well.

--
Regards, John Woodgate, OOO - Own Opinions Only.
If everything has been designed, a god designed evolution by natural selection.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk

This part of the thread was discussing loudspeakers with high conversion efficiency ( as used in SR gear ). Wide dispersion isn't a requirement *in this application*.

Home ( or studio ) audio is another matter entirely.

Graham

All depends. Typically, 180 degrees is needed for many events. You can do it with one speaker, or you can do it with many. One of my most common gripes is not hearing the music or whatever, over most of the area. If you go to a 6 inch or 8 inch max. There are drivers with at least 95 dB sensitivity. Those two drivers in parallel will boost that to 101 dB. Two more in series parallel configuration will produce 104 dB. Feeding those with 100 watts will produce

121 dB.

90% of the time, bands setup without the proper dispersion for the entire audience.

greg

My view of speaker efficiency. If one speaker produces 90 dB sensitivity, and another has 87 dB, then the 90 dB one is more efficient.

greg