🙂 you will also have an added benefit of multiple bass bins which will help spatial distribution of bass which is a good thing
Ever ask where that number came from?
Just a myth that it has any special significance. The lower the better the sound.
Ben
Isn't it because you get the flattest response in the pass band? I thought that is why it is also referenced in butterworth q factor.
I am aware that the room, the enclosure, the positioning will have an effect on this and this value is not set in stone, but it is a reference value one can aim for when designing.
If q is lower than 0.707, according to handbook for sound engineers, the response may sag and/or will fall off.
You state, the lower the better the sound? Can't say anything about it, "better" is very subjective. What do you mean by better?
I am aware that the room, the enclosure, the positioning will have an effect on this and this value is not set in stone, but it is a reference value one can aim for when designing.
If q is lower than 0.707, according to handbook for sound engineers, the response may sag and/or will fall off.
You state, the lower the better the sound? Can't say anything about it, "better" is very subjective. What do you mean by better?
A learned and measured reply. Thanks.
Flat FR is one measure of performance although less important today when we have DSP EQ. The Q of .7 doesn't make the FR flat, it is part of the model assumptions that you want to live with .7 and the model creates flat from that assumption. If you were willing to live with a worse Q, the sim would go lower.
"Q" per se matters when talking of re-producing sound (as compared to making an instrument). Dead is the baseline, not the imaginatively named perfect (??) Q. Any ringing or transient error is bad.
A sheet of SaranWrap in an electrostatic speaker is what you want, not a heavy cone with a big Q. A true horn moves a cone in that direction too.
Ben
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The reason that you see a Qb of 0.7 mentioned so much is because it provides the flattest passband response and the lowest F3. Shoot for a lower Q and you get a downward-sloping response and a higher F3. Shoot for a higher Q and you get a peak in the response and a higher F3. And BTW our ears are much, MUCH more sensitive to output levels than transient response at low frequencies.
A Qb of 0.7 provides the lowest F3. Using a lower (not worse - Q is worse when its *higher*) Q can provide more output at frequencies below F3, but the drawback is the larger box size requirement and the power power-handling within the passband. A typical design approach therefore is to shoot for a higher Q (like 0.8), then stuff the box to bring the measured Q back down to 0.7. You end up with a smaller box size and the benefits of a flat response with good extension.
Sounds like you've never heard of something called "membrane resonance"...
" Parallel wire each cabinet within and series wire them in two's."
I would find it easier to wire them in series internally, and then parallel the boxes.
I would find it easier to wire them in series internally, and then parallel the boxes.
It's processed.
They quote 135dB max out with 2KW in, that's 102dB.
JBL states that the 2269H is No=1.2%, so the pair would be 2.4%, or about 96dB.
I'll give you 6dB around 150hz or so for the cavity resonance.
They quote 135dB max out with 2KW in, that's 102dB.
JBL states that the 2269H is No=1.2%, so the pair would be 2.4%, or about 96dB.
I'll give you 6dB around 150hz or so for the cavity resonance.
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Correction: the 135dB is with 4KW in, that's 99dB.
(which makes more sense considering the T/S parameters)
(which makes more sense considering the T/S parameters)
Two 2channel amplifiers to drive the 8speakers.
Each 4ohm+4ohm combination requires an 8ohms capable amplifier channel.
If one amplifier shuts down, then you have 3 channels with 6 speakers still working until you can complete the repair.
Separate speakers with 4 channels of amplifier allow you to spread the bass speakers around the room. At least until you convince yourself that locating them at the satellites is best.
Each 4ohm+4ohm combination requires an 8ohms capable amplifier channel.
If one amplifier shuts down, then you have 3 channels with 6 speakers still working until you can complete the repair.
Separate speakers with 4 channels of amplifier allow you to spread the bass speakers around the room. At least until you convince yourself that locating them at the satellites is best.
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This all makes good sense to me.
I try to avoid higher Q speakers. I have found that even a Q value slightly above 0.7 leads to unnatural bass and many commercial speakers exceed 0.9
In all my previous listening rooms, those higher Q speakers never sound right.
?
neither do I.
Sadly Scanspeak distributor couldn't live up to its word and now I won't be having my drivers. I have only 2 at hand, which I will now use on another project. I am keen on the bass array idea and open to suggestions for the best sounding woofers suitable for my purpose! I can have them in groups of 2, 3 or 4. Any suggestions?
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