Thread: "Q" of a sub .707?

Now a while back I paid attention to this in order to find how the speaker's response would work with the cabin gain. I found out that depending second and third harmonic distortions I either liked it(clean) or I didn't(muddy). A lot of that had to do with the back wave from the subs which directly related to their position in my trunk.

Anyways, here's a post that basically says go to hell Mostly because the Qtc of a speaker can change as much as 10% just because of temperatures or other factors. Matter of fact, it's changing as the speaker plays.

DIYMA.com - View Single Post - Q alignment for sealed subs - which do you prefer?

I got sick of the same old questions being asked...so I figured I'd try to spark some interests and maybe curiosity

Leaks and cabin gain ftw. Kind of a high F3 isn't it? Must be kicker or something I've actually seen F3's on some subs as high as 40hz. wtf?

Oh wait...it's in title. Sound Splinter? I kind of figured it was a SPL sub.

Its actually a SQ sub.

But its supposed to be a big box, not that tiny excuse for an enclosure that i modeled it in.

This is what I did with mine until i blew it up:



So onto things that matter:



Look how nice and close and even it is compared to maximum SPL based on excursion.... Oh this will be fun.

Qtc of .710. But I dont care about Qtc, I only care about excursion.

So lets apply a 50 Hz second order high pass...





Looks nice....

How about we add a second order LW filter with the following specs:

F0 Q0 Fp Qp Gain (dB)
50 Hz 0.4 10 Hz 0.4 28.0 dB



Just the cabin gain in that pic above.

So with the 50 Hz HPF combined with the speaker.......

Edit:



So heres what my sub looks like with the LPF of the third order and at 50 Hz in combination with cabin gain...

LW turned out a bit different with these numbers:

F0 Q0 Fp Qp Gain (dB)
58 Hz 0.85 25 Hz 0.7 14.6 dB

Too lazy to tune it.

Looks like this:



Now for the final result of the sub in the small box:



Well doesnt that look terrible....

That really doesn't look too bad for the vehicle. Might need a little EQ but not bad. Just hope that the cross over points work well together. Phase can be a B in car audio. Most people don't realize that's where a lot of their quality is lost/poor installations.

Don't ever ask me to do this for your install....

Because the proper way to do it is to measure the drivers in their position then start playing with filters...

I should lower the level on the mids, but too lazy.

Now i'm going to see what the SDX's look like without a HPF....



Exciting.... They COULD work without a sub but the overall SPL levels might not be there.

Still worth trying since I could once again have a trunk.

Perhaps install some small subs in the rear deck instead of having the stupid 18" taking up the entire trunk and giving me ass sag.

And I didn't once look at Q.