Bridging an amp for subwoofer wiring

I just came on to say I FINALLY got it. The more I thought about it I remembered when I was switching the connections around I noticed when I had the sub out RCAs from the HU connected and running the front components the sound was really low. Last night that kept going through my mind.

Then this morning I tried something.....and you are correct......I had the LPF on in the HU and on the amp.....once I turned it off in the HU I had volume from the sub!

I then turned it off on the amp and on in the HU. Not sure if it matters which one, I figure from the HU it's much easier access to change it. So now I have some tuning to do.

I was so disappointed last night. hahaha....I am thinking this can't be that hard!!

 

congrats - now comes the tuning!

 

Glad you figured it out. Funny thing is that when I first read this thread (literally right after you started it), I thought about recommending you check the crossover settings. But then I thought to myself, "nah, it can't be that easy". I finally recommended you check after seeing you've exhausted all other options. Sorry I didn't bring it up earlier.

It really doesn't matter if you use HU or amp, but I always recommend to just use one and not both. I prefer HU because of the flexibility of adjustment.

One drawback to using the HU is that it only has preset options available (e.g. 63Hz, 80Hz, 100Hz, etc.) and doesn't allow values in between those. If you feel that something in between those will sound best, then pretty much your options are to get a high performance DSP or use the variable xover on the amp. With the amp you're still going to need to do a bit of tweaking to get the xover point set right, because you don't have direct visual feedback on your exact xover point. Your ear will be the feedback.

On an additional note, I found some info on DIYMA related to whether that amp will handle a 2 ohm bridged load. Looks like it will be stable, but output will be reduced.
http://www.diymobileaudio.com/forum/1275543-post6.html