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View Full Version : High Qts and Bass reflex...newbie Question....


March 14th 10, 04:51 PM
[ Moderator's note: while this initially appears better
suited for rec.audio.tech, I think that this may be a good
starting point for a discussion of technical figures and
their relationship to quality. -- dsr ]



I have been an analog circuit designer for decades and I have recently
rediscovered my interest in speaker design. I am playing around with
a pair of cheap "full range" coax drivers for the fun of it and as a
way to gain experience in measuring Theile/Small parameters and
playing with enclosure concepts.

The question: I have read that high Qts drivers "will not work" for
bass reflex designs. I measured the small 5.25 inch drivers I am
experimenting with (typically used in car audio) as having a Qts of
1.88. Based on my reading, this is very high (is it even too high a
value to be real i.e. I screwed up the measurement?). I would
appreciate any insight or discussion on why high Qts drivers and bass
reflex don't go together. TIA, Steve

glenbadd
March 15th 10, 02:29 AM
On Mar 15, 3:51=A0am, " >
wrote:
>
> I have been an analog circuit designer for decades and I have recently
> rediscovered my interest in speaker design. =A0I am playing around with
> a pair of cheap "full range" coax drivers for the fun of it and as a
> way to gain experience in measuring Theile/Small parameters and
> playing with enclosure concepts.
>
> The question: =A0I have read that high Qts drivers "will not work" for
> bass reflex designs. =A0I measured the small 5.25 inch drivers I am
> experimenting with (typically used in car audio) as having a Qts of
> 1.88. =A0Based on my reading, this is very high (is it even too high a
> value to be real i.e. =A0I screwed up the measurement?). =A0I would
> appreciate any insight or discussion on why high Qts drivers and bass
> reflex don't go together. =A0TIA, =A0Steve

Because you can't achieve a reasonable bass response in a
reasonable box size and tuning, compared to what can be
acheived for similar sized drivers than have a better Qts
range for bass reflex, around 0.3 - 0.5.