80dB sensitivity speaker

Uhm...strange woofer: it has a change in sensitivity (=output) of 7-8 dB just up 350 Hz- in the Driva project it is used below 300 Hz, that's why of the low sensitivity of the design. So 80 dB. It must be caused, the bump, by the big VC diameter & relative big dustcap...well, that's a membrane :rolleyes:
Big VC means big power ( at input=major heat dissipation), so a magnitude above the usual 15-20 W.
150-200 W is not doable in class A for us mortals with only tester :D
 
Hi badman, you mean 200W Class A/B per channel ?

I'm less concerned with class of operation than with clean power output. My personal preference is for Hypex NCore (Class D), which has plenty of power for just about anything.

The power isn't just about how loud you play- more powerful amps tend to handle dynamic swings better. That's not universal, 45 tubes to me sound very dynamic on the correct speaker, but also wouldn't drive the ones you're looking at at all (45s are only approx 1W in SET).
 

norman bates

Member
2003-11-25 2:28 am
I agree.

I've read (and a buddy verified) some amps that were switchable class-A to class-AB, no difference in listening quality.

But power, high voltage rails (maybe delivering current better into the high Z-spike of sealed or ported box?), bypassing, regulated front end, and especially amount of feedback affecting clean output, perhaps affect what you hear (dynamically anyway, low tim distortion).

Maybe part of the class-D sound is the small power supply caps able to discharge so much faster than say a 3kuF cap.

200w on an 80db speaker ain't a lot of volume.
I had 200w on 83db 1w/1m.
 
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Depends on your listening preferences.

I've had 100w/ch into some [email protected] speakers, and that was plenty loud for domestic use - I could feel the drums, but my living room is around 4m x 5m, so not a huge space.

Most of the time, I listen around 60-70dB, so that's milliwatts. In that case, the 10w class A amplifier mentioned above would be adequate.

Remember, the first watt is the loudest. Every doubling of perceived volume requires 10x power.

Chris
 
Uhm...strange woofer: it has a change in sensitivity (=output) of 7-8 dB just up 350 Hz- in the Driva project it is used below 300 Hz, that's why of the low sensitivity of the design.
I think that is just due to the measurement method (IEC baffle) Morel used in the datasheet. Should be more or less a flat response from ~500Hz down. Sensitivity at low frequencies will be close to the T/S derived figure (85.9dB/2.83Vrms). The sensitivity of the completed design is probably 3-6dB lower than this due to baffle step compensation.

80W/ch is plenty for my speakers based on DA175-8 (85dB) and 3-4dB baffle step compensation, giving ~81dB sensitivity. Xmax is being exceeded and distortion is audible way before I hit the power limit of my amp. 20W would work perfectly for smaller rooms or near field listening.
 
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Hi Ckwong,


you´ve chosen a very strange loudspeaker design, which does not make so much sense to me, but that´s just my personal point of view. A suitable bass driver for combination with the SEAS coax should maintain some 87 - 89 dB between 300 and, let´s say 40 Hz, and that´s no witchcraft. Of course, that will be most likely an 8-inch-driver.
Such a combination should be able to reach decent loudness levels with a 15-watt-classA amp.


All the best


Mattes