Hey guys

I am currently installing the following gear into my car:
Alpine CDA-7998r
Alpine SPX-F17T 3 ways
2 Alpine SWR-1241D DVC Type R's
Soundstream Reference 644s 75*4 rms
Soundstream Refernece Class A 10.0 1000*1 rms

Firstly, sorry for the length of this post, but i have a few q's . Both the amps are class A, so they should be perfect for my system as i'm planning on designing it purely for SQ. What i want to know is should i bridge two channels per side of the 644s to the splits, to get around 300wrms per side, or should i run them in a dual amp config, so 75w to the midbass and 75w to the midrange and tweeter? Any help is appreciated. Also what is a good value sound deadener. I know that all it does is add mass to the panels to stop them vibrating, and that bunnings sell a product VERY similar to Dynamat. Do you think it would do the same job?

Thanks
Brad

try doing both configurations with the front amp and then stick with whichever one sounds better.

from looks of things u have a good start to a great sounding car.

and ur post isn't really that long at all.

its a little hard to say whether you should bridge for more power, or instead run each driver off a channel and dump the passive crossovers. I had the same dilemma when i got my subamp and freed up the 4 channels on my orion. So i gave them both a go. In my case, it was the bridge for more power rather than the active setup which worked for me. But i stress, you have to try it for youself since our drivers/amp/environment couldnt be more different.

Remember to watch the gains and crossovers points very very carefully when you run active, esp with regards to your tweets, or you'll blow them. I suggest a good test tone cd. Start with low gains/high crossover point for the tweeter and slowly work your way up the gains and down the highpass point for the tweets until you're happiest

But offhand, from my little experience, i would suggest you run active provided running active, you are still feeding your front speakers at least RMS power + about 20% overhead. If running active means running below RMS power, chances are bridging will work out better i think. Like in my case. Power before crossover. May the force be with you

Oh yeah, dont aim too low for the tweeter highpass just because your tweeter can handle it, cos the overall sound will still suffer. Driving 62.5W to my Morel MT2 tweeter, it could easily handle 1900Hz highpass at 12db/octave without distortion on test tone frequencies below the crossover point at max listening volume BUT once i powered up the midbass drivers, the sound was awful. it was like the whole front stage was being played by the tweeter, which made the overall effect hollow and lifeless although distortion free(after all , its only a 1 inch tweeter). Provided your tweeters are up to the task, i dont recommend crossing over below 2500Hz. My passives crossovers highpass at 3000Hz on a 6db/octave slope and i cant find fault with it really. I liked the sound best at this point. And with 250W x 2 to each channel bridged, it sounded fantastic.

BTW the slightly increased THD from bridging is not a factor in this. There will never be an audible difference. Just in case you're wondering. The increase is usually from something like 0.08 to 0.2%, something like that(unless you got a crappy amp, and youre amps arent crappy!). Only the best ears out there can hear about 3% distortion or more. I wouldnt worry about it

[ May 07, 2003, 16:55: Message edited by: honour77 ]