Figured I'd share a "Duh!" Moment..

[chris15]

So, I've helped a bunch of people install car audio equipment, made product suggestions, and done my own work as well. I went through high school planning to major in engineering, and took a digital electronics class. It was great fun.

In my systems, I've gone through a fair amount of parts and finally I installed an Alpine 12" Type-R (1242D) sub rated at 500wRMS/1500wMAX with a Sony XM-ZR1852, 2-channel amp. It was sweet, and a definite upgrade from the Pioneer sub I had in there previously. The Alpine is a 4-ohm dual voice coil sub. When I ordered the sub, that specification stuck in my head. When it arrived and I installed it, I wired it up the way that WASN'T the 2-ohm load configuration, and wired the voice coils in SERIES. I assumed that the overall load would have stayed at 4-ohms. Since I've frequented shows and whatnot, I was impressed with the Type-R but it seemed to be lacking volume and sound quality, but just figured it was my ears and wasn't anything huge. I have the 2-channel Sony bridged to 400wRMS at 4ohms. When comparing systems of people I know, the Type-R kept up but I knew on the inside that it should be crushing all of the Kicker CVRs, Polks, and the like, but it wasn't. I used the gain settings on my headunit to compensate for the lack of volume from the sub. Then, last night came my revelation:

I have a 4-ohm dual voice coil sub with the coils wired in SERIES. That creates an 8ohm load, which means that my speculations were wrong. The amp, seeing the 8ohm load, is only pushing 200wRMS, instead of the 400w I had assumed. I really can't believe I overlooked that..

Now, my situation is that the Sony amp I have isn't 2-ohm stable, so I'm picking up a Kenwood Mono Block KAC-9102D amp from a friend tomorrow. (850wRMS @ 2ohms) And now I won't have to risk clipping the amp anymore!

Hopefully some of you understand the humor in this post!

[CREWZIN]

Right over my head Chris, but glad you got it figured out.

[chris15]

Thanks Carey! It kinda is a bit complex but the basic idea is that I was really, really dumb.. hahaha

[Hooligan]

What did he say???

[Chromenut]

I understood "sub" and "speaker", the rest was Greek to me...

[chris15]

Well, irregardless, I'm picking up my new amp in about 2-3 hours. It's pretty monstrous..

Kenwood KAC-9102D Mono subwoofer amplifier 500 watts RMS x 1 at Crutchfield.com

[chris15]

I think it's time for some serious wire re-routing.

[Knotsobright1]

I know exactly what you mean Chris and it will drive you nuts trying to figure out why it sounds so bad. Its bad enough how addictive that hobby can be but when you get something new and its sounds off then you start thinking of more stuff you "need"

[Knotsobright1]

BTW I see you are running the db6501 set. You should hear the MM series they are cleaner and the response seems better. I am running them in my colorado.

[chris15]

Oh, I'm happy with how it sounds, it's just quite a mess of wires and whatnot, and the amps are a tad bit too big to fit under the seats where I had my previous ones set up, so I'm going to have to relocate. Thinking about moving them to the trunk but not really excited about having to (quite possibly) run a 1/0-gauge wire from my battery to replace the 4-gauge that's already there.. I'm now running about 750-watts RMS total (100wRMS to each set of front speakers = 200wRMS from the Sony amp and then a touch higher than 500wRMS to the Alpine Type-R from the new Kenwood amp) so the 4 gauge wire is probably not going to cut it for long.

I'm actually really happy with the db6501s. I compared them before I bought them and considered the MM6501s but for the deal I got on the db's, I just went with those. Most people who complain about the 'sound clarity' difference between the db series and the MM series are the result of underpowering the db's. I moved my Sony amp (the one pictured above) from my Alpine Type-R over to the Polks up front, and now have the gain at about half, should be ~100-watts RMS/300-watts max per channel and the db's sound b-e-a-utiful! I am considering, however, eventually adding a second set of components up front, in addition to the ones already installed (second set of woofers in kick panels, second set of tweeters on the dash/inside A/C vents).