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View Full Version : Boston Pro + 4 channel amp



kmu
03-18-2008, 07:34 PM
HI there, I currently have an Alpine 4 channel amp model MRP-F450

RMS Power (at 14.4V THD+N, 20Hz-20kHz)
Per channel into 4 ohms: 70W x 4 (0.08% THD)
Per channel into 2 ohms: 100W x 4
Brigded 4 ohms: 200W x 2 (0.3% THD

Now the Boston Pros are 3ohms

How should I power them? could I bridge the amp? would it be stable @ 3ohms bridged?

I have not received the comps yet, but the online manual shows a separate crossover for each mid and another one for each tweeter, could I run each channel of the 4 channels to each crossover?

Im currently feeding the signal to the alpine 4 channel amp via speaker level inputs from the oem HU so going active would be almost imposible.

THX in advance

lostdaytomorrow
03-18-2008, 09:37 PM
Yes, you can run them bi-amped and use all 4 channels.

kmu
03-19-2008, 09:33 AM
Yes, you can run them bi-amped and use all 4 channels.

How would I need to wire them, for example: front left channel on the amp to driver side tweeter, and rear left channel to driver side midwoofer, then do the same to the passanger side, is this the way to do it?

How many ohms is the midbass and how many the tweeter?

as anyone done it this way?

THX again

ace_800
03-19-2008, 10:07 AM
I would just bridge the amp and run them like normal with the xovers. IIRC the ohms on the tweeters were 6.5ohms. I don't remember the woofers. They are deffinitly power hungry comps.

kmu
03-19-2008, 11:06 AM
I would just bridge the amp and run them like normal with the xovers. IIRC the ohms on the tweeters were 6.5ohms. I don't remember the woofers. They are deffinitly power hungry comps.

This would be the easiest way for me to power them

Would it be OK on the amp to bridge it on a 3ohm load?

kmu
03-20-2008, 11:40 AM
Would it be OK on the amp to bridge it on a 3ohm load?

Anyone on this?

THX again

Cmonster
03-22-2008, 07:04 PM
I have the Boston Z's and the Pro's. Both are run off of 4 channel amps bridged. There can be a heat issue if I run them too hard for a long period. The 3ohm load causes the amps to run a bit hotter. Both amps are Arc Audio (FD 4150 and FD 4100). I talked to Brad there about this issue and he said it should be cool.

kmu
03-23-2008, 01:31 PM
So it is OK to bridge the 4 channel amp into a 3ohm load?

If I dont bridge it I will be given each comp around 85 watts rms from the front 2 channels, now if I bridge the amp the comps will be getting around 200 watts rms each.

kmu
03-25-2008, 04:08 PM
So it is OK to bridge the 4 channel amp into a 3ohm load?

If I dont bridge it I will be given each comp around 85 watts rms from the front 2 channels, now if I bridge the amp the comps will be getting around 200 watts rms each.

Anyone...

R05Nismo
03-27-2008, 09:32 AM
Anyone...

Just try it both ways and see what happens. Your amp will be running at 1.5 ohms per channel if you brigde it which may or may not cause problems.
I have the Pro60's but didn't get them in yet, I did some research and most say they need a good 150rms to each side.

wvufootball
03-28-2008, 12:38 PM
My amp is prob putting out 100-120wrmsx4 to my pros and they are plenty loud. Loud enough to keep up with a ported 13w7. Just saying you don't need that much power, but a little headroom never hurts.

kmu
03-28-2008, 03:59 PM
My amp is prob putting out 100-120wrmsx4 to my pros and they are plenty loud. Loud enough to keep up with a ported 13w7. Just saying you don't need that much power, but a little headroom never hurts.

What amp are you using to power the comps and which one for the 13w7?