Dual Opposed AV15H Subwoofer Build - Page 8

Hmmm, I thought about this as my speaker wire is much shorter to the sub showing the lower dbs. But recall reading somewhere that unless the wires were very long it wouldn't make a diff (one is 6 feet, the other about 3 feet, simply because I was getting sick of trying to hide long wires!). But I can try equal distance wires to check for that when I get home later today.

Note those readings were taken before the subs were hooked up (as I understand this will fluctuate depending on what the amp is delivering).

Will also remeasure the impedence at the terminals with a 60hz tune going to both when I remeasure the voltage at a higher output than 100db.

Edit: I also seem to recall that when I was measuring impedence of the drivers (I wired both pairs before putting htem into their boxes just to check) that one set went to 3.2 almost immediately, while the other pair seemed somewhat erratic before settling on 3.2. May mean nothing at all, or something!?

Is there a way to check for this as that's what I'm wondering as well? Looked at the terminal cups and they are on pretty darn tight (used some soft cell foam under them as well). I put extra glue and caulk on the interior of the sub (and exterior where the baffle is), plus I just checked the woofers and they seem on tight as well, but could be leaks there I guess?

Just checked the voltage with a much higher SPL from a 60hz test tone, both woofers were measuring 4.2 on the meter (well, one was 4.2, the other 4.3).

Not insulting at all! Would love it if it was a stupid easy to fix mistake. So I just take a small 9V battery and touch the banana plugs to each side (+/- doesn't matter?)?

BINGO! On the faulty sub one of the woofers pushed out while the other pulled inwards on the 9V batter test. Thank you!

Now for the painful process of pulling the woofers.

Fixed!! Lucked out and the first woofer I removed clearly showed I connected the black wire to the red terminal (my wires are all white and I used black electrical tape on the ends to mark them but like a moron connected it to the red anyhow! ).

Just watching the Pacific, amp channels now make sense (the sub near the doorway requires a tad more gain than the one up against the wall, but not much).

Have my fronts crossed at 150hz, will see how it goes. Hopefully take some measurements tomorrow evening (wife and son may be out for a bit).

Yeah, me too. By fun do you mean incessant measuring and tweaking while listening, constantly, to test tones?

On a completely uneventful note, had to watch The Pacific at -30db to reference with my son asleep upstairs. So hard to really compare how the subs were doing!!

Crossed my fronts at 150hz just to try them out, and again, this may be a useless comment given I've never watched that particular episode before, but it did sound like my fronts were having a much easier time reproducing what they needed to. Things seemed clearer than they normally were with Pacific, in particular with ambient noises and speech (which I complained about in the Pacific thread on the sub forum and others in Canada have as well as it appears the mix up here is more compressed).

But that could just be new sub placebo effect.

Oh, and the fan noise was utterly attrocious. I'm quite picky when it comes to noises and the fan was audible 95% of the time (outside of some battles scenes). Hopefully my new fan will arrive shortly, though I'm not looking forward to trying to get that amp out of the rack given I had to remove the doors to get it in the first time around (may just pull it out the back).

The gains are so close I doubt it will be an issue either way (probably the fact that the additional gains from the extra boundary in the corner are offset by the better FR achieved from the other side?), but yes, I can simply set them the same given it's not that big of a difference.

If I can get home at a decent time tonight and am alone I'll try to run some sweeps at varoius SPLs and various x-overs.

No, they are a 90 degree angle, so they don't meet perfectly at the bottom given the rounded edges on my woofer. Actually, I've currently got them on with Velcro as they are just their for looks more than anything else. Debating whether to put in threaded inserts.

Nope, no slight curves on it...

May try to test it eventually against the Ultra if I find the time. Going to try and run some REW curves of the room right now at the LP if I can recall how to setup the SB USB audio device and REW on my computer in time before my son gets home...

Hmmm .... as I'm setting up the REW I've been watching the Pods Emerging scene at -7db. I can tell you these subs must be rolling off significantly as they are no where near the visceral impact of the PB13 even in sealed mode. Somewhat surprised by this actually. Barely felt anything when the Pod breaks through the ground which is typically rumbling my house insanely. Even when the Pod starts to fire it's lasers, very little impact whatsoever in comparison. Suprising given the lasers I thought were around 25 to 35hz so I would have figured these puppies would shine at that.

Hopefully some graphs to follow shortly that will explain what is going on...

WEIRD, so I'm using my laptops internal card, and when sending a signal to my processor at a high level (say -10db on the processor) to get a level of at least 75db, my receiver's protection goes off and the AVR shuts down and light starts to flash. What the heck?? Wonder if it's because I've unplugged my mains and the AVR is still set to 7.1?

Took several measurements (turned out I should have unplugged my front speakers at the AVR, not the speaker ...). Had clipping errors when I tried to run graphs above 90db (not sure if that was my processor/amp or computer sound card), but will post the results anyhow.






This one is with the S2's and Subs together crossed at 150hz ...



Meter used is the Galaxy CM-140 with appropriate calibration file applied to REW.

Thoughts? Anything else I should post from REW?

Here is the response 6" from the cone for each sub ...

Corner Sub



Doorway Sub

Are you saying above 90 the amp will clip? Sorry, not sure what you're inferring (not a power user of REW or measurements for that matter so go easy on me!).

Here are all the sub only measurements on one graph (didn't realize that tab was there!)...