Just looking at the power restraints of the drivers, it may be better to run the amp on stereo so you don't damage the drivers. Otherwise when bridged I would not imagine the noise being too noticeable with sub drivers since the noise probably is too high and weak to move the sub drivers.

 

Hello... There isn't any real risk by using an amp that's higher powered than the drivers, in fact, it's recommended. I believe Crown even recommends at least 2x over the RMS rating to provide sufficient overhead for peaks. If it was just a matter of picking power - I'd pick the bridged mode, since that would give plenty of overhead.

And even if the drivers don't move - you can hear noise - if there is sufficient noise in the signal path. I just would like to minimize the level of noise...

I was just curious what others do - if they they can hear higher noise levels due to bridging. I recall Mark Seaton making a recommendation in another post to someone - to get a higher power amp - rather than bridge a lower powered one -- in order to minimize noise.

 

Wire the subs for a 4 ohm load and run the amp bridged. When using a EP4000 for subwoofer duty and crossing over at 80 hz, "increased noise floor" is a non issue. You can test this for your self, run the amp bridged and then one channel to each sub, see if you can hear a difference.

 

Mike - I'm apparently guilty of asking the question before trying myself!

I was hearing some noise (hiss? far above 80hz) when I was playing around. I read that it's probably due to incorrect gain structure (quite likely since I just spent 2 minutes or so) -- or it could have easily been other components that I didn't rule out (a Rane EQ and a BFD).. For some reason I jumped to the conclusion that maybe it was noise from the amp bring bridged. (Lazy logic???)

As always, thanks for your input.

 

If you are hearing noise take the Rane EQ and the BFD out of the loop and see what the result is. It's a process of elimination to find the problem.

 

Was planning on it - just hadn't had a chance...

For some reason having a 4 month old cuts into my playing / troubleshooting time.
:neener::dumbcrazy:

 

I'm not really familiar with your particular amp, but I would agree with going bridged. On a Crown, the distortion level is rated from a very low frequency to 1kHz with .707 max power applied. So using your amp at well below 1kHz, combined with the added headroom of using it bridged, should actually equate to less noise . This is my understanding anyways. I'm fairly certain this applies to all amplifiers of this type.

Sounds like a fun build. Do you have a build thread for it?

 

I don't have a build thread.. I keep meaning to start one! It's partially built -- so really I need to take some pictures and start posting..

 

My circle jig is homeade but works just as well as any other (a little fine tuneing involved though). I do wish my router was a plunge router however.
A good tablesaw next on your list would make life 100% better, i finally got one a few months ago and what use to take 1 1/2 hours to cut down sheets for speakers now takes 15 minutes (gotta love it) bafore i was setting up a straight edge and using a circular saw talk about a headache. Anyhow enough rambleing on, Can't wait to see your build.:T

 

Hi, paralleled will provide better damping, bridged increases noise floor (in theory), but allows multiple speakers on two wires and needs a powerful amp accordingly.:hsd:

 

So, if you have two 500 watt drivers (EV, Exodus, doesn't matter) that are 8 ohm ((I realize that many sub drivers are 4 ohm - but for my application they are each 8 ohms)...... and an EP4000...

Does it make more sense to:
1. Use stereo and power each driver with each channel of the amp (450w/8 ohm channel, 900 total)
2. Wire the drivers in parallel and bridge the amp. (1957w/4 ohm load)

I've read that some people recommend avoiding bridging amps because of the increased noise floor. Is the choice basically - bridge it for more headroom and power and put up with the extra noise......... Or run in stereo and put up with the reduced output?

Until I read the discussion about noise and bridging - I would have logically just bridged it - since you get twice the power. Any thoughts/comments?

Numbers below are from a "Measuring Amplifiers" thread on AVS:
Stereo, 8 ohms 450
Stereo, 4 ohms 650
Stereo, 2 ohms 1,100
Bridged, 4 ohms 1,957
Bridged, 8 ohms 1,300

using the amp in these modes, does this mean each sub would get 1100, 1957 and 1300 watts a piece OR each sub would get 550, 928 and 650watts a piece?

 

I believe these measured values are in watts per channel, as output from the amp. So, with a two sub system, the stereo numbers are watts to each sub. The bridged numbers should be total output power. You would have to divide the bridged numbers by the number of subs to determine power applied to each individual sub.