Wiring Avalanche 15"?

[rthornhill]

I recently purchase two 15” Ascendant Audio Avalanche subs based on many of the recommendations of this forum. I really got a lot out of this forum, there is a lot of great information. I especially liked the “DIY newbie” thread started by ajpoe.

Well, it has taken me waaay too long to build two sealed enclosures. I have not heard a peep from the AAs since they arrived on my doorstep. And before I seal those beasts into these caskets, I wanted to confirm my plans for wiring.

I will be using a QSC RMX850 bridged to mono to power the subs. I “think” that I should jumper the positive (+) of one voice-coil terminal to the negative (-) of the other voice coil terminal and run leads from the other two terminals out to my speaker posts. This should give an average impedance of 4ohms for each cabinet. Then, I should connect the two cabinets together much like the voice-coils (jumper + from one speaker to the – of the other and run the two other leads back to my amp). This should give an average load of 8ohms.

Just wanted to double-check before I sealed them in. Thanks.

[ThomasW]

Yep sound fine..... :T

[kgveteran]

How did the project go, as far as the build ? What is the rest of the system ?
I would agree that the end product would be a 8ohm load.

[Dennis H]

There are potential problems running the drivers in series if the T/S parameters of the two drivers aren't identical. It's probably not a big deal but it exists. You will get the same SPL if you wire each box to be 4 ohms and run the amp in stereo with each channel driving a box. That's what I'd do.

[rthornhill]

Again, thanks for the help. I knew how to work with resistances in series and parallel, but wasn't exactly sure if the polarity of the speaker leads would come into play. You could connect the positive connections of the voicecoils together and still get the 4ohm net across the negative leads.

Almost done with the boxes, they measure 22" x 22" x 30"high. Glued the bottom inplace last night. The front baffle is about 2.125" thick and the remaining walls are at least 1.5". I used internal bracing of .75" plywood and 2x4"s. I will hopefully spec it out in my living room this weekend.

The Thiele Small parms should be close on the two cabinets. The dimensions are very close, less than .125" maximum in any direction. I used approximately the same volume of fiberglass insulation in each; but I didn't actually weigh it. I would like to run the amp in bridged mode, but will run in stereo if the difference warrants it. The specs quoted by QSC seem to be "better" when running bridged.

[Owen Bartley]

I can't be the only one who wants to see pictures of this beast... how bout it, rthornhill?