To bridge, or not to bridge
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I think you're wrong about the bridging, when bridging youd hook up the left channel RCA to the 'front mono' input, and the right channel RCA to the 'rear mono' input. Then youd have the 'front mono speaker outs' power your left speakers, and the 'rear mono speaker outs' power your right speakers. When bridging the speakers, it sums the input channels, so you could probably still get full power by turning up the sensitivity.
I can wire this setup easily, the ONLY issue I am worried about is the sound quality of a bridged speaker output. It probably has much higher SNR, BA doesn't list this numbers so theres no real way of knowing.
Since nobody here is giving me a difinitive answer on the quality issue, I think I'll wire the car with 2 sets of speaker wires to each channel. It's only at WORST 50 extra$(more likely 20) of 16ga speaker wire, and this way I can listen test all the different setups.
When measuring the speakers I got 3.3 ohms for the woofer, and 5.9 for the tweeter OUTSIDE the crossover. I had trouble measuring the devices while they were IN the crossover circuit, because of the caps absorbing my multimeters charge and therefore altering the resistance... How did you manage to measure it?
I'll just keep the gains REALLY low, and see how it sounds, if I don't like it, I can always go bi-amp like you said.
Thanks for your help Will!
I can wire this setup easily, the ONLY issue I am worried about is the sound quality of a bridged speaker output. It probably has much higher SNR, BA doesn't list this numbers so theres no real way of knowing.
Since nobody here is giving me a difinitive answer on the quality issue, I think I'll wire the car with 2 sets of speaker wires to each channel. It's only at WORST 50 extra$(more likely 20) of 16ga speaker wire, and this way I can listen test all the different setups.
When measuring the speakers I got 3.3 ohms for the woofer, and 5.9 for the tweeter OUTSIDE the crossover. I had trouble measuring the devices while they were IN the crossover circuit, because of the caps absorbing my multimeters charge and therefore altering the resistance... How did you manage to measure it?
I'll just keep the gains REALLY low, and see how it sounds, if I don't like it, I can always go bi-amp like you said.
Thanks for your help Will!
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From: Albuquerque, NM
Originally Posted by nothing235,Mar 14 2006, 08:34 AM
When measuring the speakers I got 3.3 ohms for the woofer, and 5.9 for the tweeter OUTSIDE the crossover. I had trouble measuring the devices while they were IN the crossover circuit, because of the caps absorbing my multimeters charge and therefore altering the resistance... How did you manage to measure it?
I'll just keep the gains REALLY low, and see how it sounds, if I don't like it, I can always go bi-amp like you said.
Thanks for your help Will!
I'll just keep the gains REALLY low, and see how it sounds, if I don't like it, I can always go bi-amp like you said.
Thanks for your help Will!
Also, I didn't realize the BA amp had a mono rca input... thought it would have a stereo input and it would combine them for a mono output.
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Originally Posted by Will,Mar 14 2006, 10:27 AM
Also, I didn't realize the BA amp had a mono rca input... thought it would have a stereo input and it would combine them for a mono output.
The BA amp has front channel 'stereo inputs only'(no mono inputs). It does have mono rear inputs however. Also it has mono outputs for both channels.
I am almost positive I can run 4 RCAs pre-outs from the head unit, and just cross the wires like so:
FR = Front Right
FL = Front Left
RL = Rear Left
RR = Rear Right
Head unit --> Amp
FR ------> FR
FL ------> RR
RR ------> FL
RL ------> RL
Then use
the Amp Front Speaker Output in mono mode as my 'Right Side Speaker'.
And
the Amp Rear Speaker Output in mono mode as my 'Left Side Speaker'.
This does require more RCAs but I think it will be the best setup. It also allows me to use only one set of speaker wires per set of speakers in 'non bi-amp mode'. I just hope bridging the channels like above wont increase the SNR to an audible level.
Thanks again for your help Will! If anybody reads this and sees that I am about to do something stupid PLEASE let me know!! I wont start testing until this weekend at the earliest because thats when my head unit arrives.
Thanks.
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From: Albuquerque, NM
You can also use rca splitters... like this:
FR--------->FR, FL
FL--------->RR, RL
but overall I guess the only thing to do is try it. You won't screw anything up. But i'd recommend turning the gains waay down at first.
FR--------->FR, FL
FL--------->RR, RL
but overall I guess the only thing to do is try it. You won't screw anything up. But i'd recommend turning the gains waay down at first.
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From: Albuquerque, NM
Originally Posted by modifry,Mar 14 2006, 07:42 PM
1. If we believe BA that the amp is 45W at 4 ohms and 140W at 2 ohms then it's a pretty good amp. A "perfect" amp would give you 180W at 2 ohms, a crappy one would barely double the power to 90W. The fact that you get over 3x the power when bridged is a testament to the amp's design and high-current capability. Chances are it will sound great bridged, but if you can hear the noise difference you should either take it back or check yourself into the Smithsonian (for display as the worlds best ears). 
2. Tweeters, unless crossed over really low (below 1000 Hz) typically don't use anywhere near the same power as mids or woofers. So by bi-amping you're wasting a 45W amp on a driver that will likely never see more than 5 or 10W. By running bridged you let the cross-over send the power where it's needed - a more efficient use of the power you have available.
.
2. Tweeters, unless crossed over really low (below 1000 Hz) typically don't use anywhere near the same power as mids or woofers. So by bi-amping you're wasting a 45W amp on a driver that will likely never see more than 5 or 10W. By running bridged you let the cross-over send the power where it's needed - a more efficient use of the power you have available.
.
Multi-Ch. Power @ 4-ohm (12.6VDC)
4x45W
Multi-Ch. Power @ 2-ohm (12.6VDC)
4x70W
Dual-Mono Power @ 4-ohm(12.6VDC)
2x140W
Dual-Mono Power @ 2-ohm (12.6VDC)
2x175W
when the car is running and you have 14.4v the rating goes up to 55w per channel at 4 ohms.
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Thanks for clearing that up Modifry.
Either way Will, I think bridging is the way to go for now.
I'll add to this thread and let you all know how it sounds when I have it all set up in a couple weeks.
Thanks everyone for the tips!
Either way Will, I think bridging is the way to go for now.
I'll add to this thread and let you all know how it sounds when I have it all set up in a couple weeks.
Thanks everyone for the tips!
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From: Baton Rouge, LA
Originally Posted by Will,Mar 13 2006, 06:46 PM
If you only have one pair (left and right, in the doors) then you will not be running a 2 ohm load. You can run 4 ohms, which will give you 45w x 4---45w to each tweeter, and 45w to each mid. Running in 4 ohms will allow the amp to run cooler and gives you lower THD anyway (though I doubt your ears could tell the difference). I don't think running bridged will give you better power distribution--technically, if the speakers are the same impedance, they'll get the same amount of power anyway (somebody please tell me if i'm dumb for saying this)? And the included BA crossover actually physically splits (see link to manual below) so it blocks low freq's to the tweeter and blocks high freq's to the mid.
http://www.bostonacoustics.com/manuals/SL60Man.pdf
so, he does gain power.
also, i'm 99.9% sure that the SL60's are 4 ohms for both the biamp and non-biamp'ed configurations.
So I thought of something I didn't notice before--you don't want to bridge the amp to run these speakers. Why? Because when you bridge you are bridging the right and left channels, eliminating stereo sound. You're converting to mono. You'd have to hook the front channels to one component set and the rears to the other. I don't know how it would sound but i'm guessing like crap. Not to mention you'd be at almost double the rated power for those speakers, so you'd have to turn the gains way down. But how far? You won't know for sure.
I think you're wrong about the bridging, when bridging youd hook up the left channel RCA to the 'front mono' input, and the right channel RCA to the 'rear mono' input. Then youd have the 'front mono speaker outs' power your left speakers, and the 'rear mono speaker outs' power your right speakers. When bridging the speakers, it sums the input channels, so you could probably still get full power by turning up the sensitivity.
I can wire this setup easily, the ONLY issue I am worried about is the sound quality of a bridged speaker output. It probably has much higher SNR, BA doesn't list this numbers so theres no real way of knowing.
Since nobody here is giving me a difinitive answer on the quality issue, I think I'll wire the car with 2 sets of speaker wires to each channel. It's only at WORST 50 extra$(more likely 20) of 16ga speaker wire, and this way I can listen test all the different setups.
Since nobody here is giving me a difinitive answer on the quality issue, I think I'll wire the car with 2 sets of speaker wires to each channel. It's only at WORST 50 extra$(more likely 20) of 16ga speaker wire, and this way I can listen test all the different setups.
and Will is right -- RCA splitters will work just fine.
bugger - teach me to start respoding before reading the whole thread.... lol. thanks modifry.
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Thanks again guys! Hooked it up last weekend in non bi-amp mode. It sounded pretty good at low volumes but the tweeters, being mounted closer to my ear, were a bit too loud for my taste.
I popped a 10 ohm resistor on their speaker line (they measured 7 ohm) and now it sounds amazing! Now I just have to get a sub box built!
I popped a 10 ohm resistor on their speaker line (they measured 7 ohm) and now it sounds amazing! Now I just have to get a sub box built!
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