High Q vs Mid Q vs Low Q (1 Viewer)

[matt.r.w]

Hi all,

I'm looking for advice considering Q ratings.
What Q is best for strictly home theater use? Looking Adire's reference plans they seem to say that high Q (.9) is for HT/Rock use, but most people seem to pick mid Q (.707). I've also noticed a lot of people frown on a "boomy" High Q... Remember, I'm asking strickly about HT use, not music.


tia
Matt

 

[Patrick Sun]

It you want a more natural HT presentation, keeping the Q between 0.5 and 0.707 is probably the way to go. Once the Q gets high, near 1.0, it's underdamped, and gets sloppy sounding.

 

[Aaron_Smith]

If I were building for HT only, I would consider a vented design. You'll get better low frequency extension and better efficiency, at the expense of some tightness and clarity.

 

[Ryan Schnacke]

Q alone doesn't mean all that much. For instance, the EBS vented alignments that are quite popular are high Q alignments (Q > 0.7). But since the box is tuned below the resonance frequency of the driver, the bass response does fall off a little before turning that hi-Q corner. And the tuning frequency is so low that the excess transient delay occurs at frequencies below our hearing threshold.

But a high Q alignment with a higher tuning frequency (like you might get with a sealed box) can sound a bit boomy. The tuning is above resonant frequency so instead of an Extended Bass Shelf you get a hump somewhere just above the tuning point.

Try simulating a few different alignments and experiment with different Q's. That should help you understand this stuff better than I can describe it.