Yo.

I was chatting with Matt from Arvus today, and in order for the PR i'm wanting to work best, i need woofers with a Q of 0.4 or less, definately no more than 0.42...

I take it he means Qts? And if so, what high-wattage-handling recognised SQ subs are there on the market with a low Q like this?

DD 9510 has a Qts of 0.25 when the coils are run in series like i will be, DD 3510c is 0.35, DD 3510d is 0.35...

None of the following will suit, they all are too high (0.50 plus) : Diamond M6, TDX, JL Audio W6, W7 ... which rips me out a bit, i was deadset keen on the TDX's

Any other options?

P.S If any of the suitable subs come thru a brand we stock or can get access to (see below), all the better

A Q factor that is small like that indicates that the woofer is efficient over a narrow bandwidth, if a woofer has a higher Q factor it is not as efficient over the given bandwidth, but the bandwidth is wider.

The Q factor of an enclosure is how the enclosure interacts and affects the frequency response of the woofer.

Out of the brands you have listed at the bottom of your sig I know DD will do the job, Kicker Solo X would too I don't know about Arvus and I dont think MTX would do the job.

I have noticed a correlation between Fs and Q as Q is basically a measure of how the Woofer Cone is controlled so if you want a small Q factor, look towards woofers with a "stiff" suspension to narrow down your search.

Yeh, the reason why it needs to be a low Q is because the way they design and tune their PR's to suit that type of driver... he's said that if i can find a driver with a Q that low, he can tune the sub/box/PR combo to give flat +/-3dB response to 18Hz, which is what i'm after

Another unrelated question : does cabin gain continue on as you get into subsonic frequencies?