Amp question

[Amiers]

I have recently upgraded our speakers in the theatre and wanted to make sure before I go full force with them in shows that nothing is going to get damaged. I know a little about sound equipment but I just want to make sure as a precaution.


Speakers:

4 MRX515s @ 8 Ohms each

2 speakers on CH A
2 speakers on CH B

Amp:

Crest Performance CPX 2.0

The amp is set in stereo mode.

From what I have read in the manual and in the spec section is where I get a bit confused. The sticker on my amp says it is a 1000w/2 ohm amp but the manual lists about a half dozen different Rated power settings. So if someone could help clarify and or tell me if I am going to break something that would be awesome. So it can be fixed.

 

[Call911]

2 8 ohm speakers would pull 4 ohms on the amp. In stereo mode you want to look at the chart for stereo 4 ohm. That will be your max watt rating.

 

[Talley]

The short explanation is:
Bridged is running both channels of the amp combined as one channel.
Stereo is running both channels independently of each other.

CPX 2.0 specs
- Rated Power (4 ohms bridged) 2,000 W RMS; 1 kHz @ <0.1% T.H.D.
- Rated Power per channel 2 ohms, 1,325 W RMS; 1 kHz @ <0.1% T.H.D.
- Rated Power per channel 4 ohms, 825 W RMS; 1 kHz @ <0.05% T.H.D.
- Rated Power per channel 8 ohms, 500 W RMS; 1 kHz @ <0.05% T.H.D.

MRX 515
CONT PRGM PEAK at 8 ohms
400 W/ 800 W/ 1600 W, 2 hrs
350 W/ 700W/1400 W, 100 hrs

So with two of the boxes daisy chained together on one channel the load is 4ohms. So the max you could get from each channel of that particular amp is 825w at 4 ohms total for both boxes not each box.
That will work but most, including myself, would consider that a little lite and if you are going to be using it to really crank up those boxes then you should maybe look into trading up to something with a little more gusto. You will always do more damage under powering than you will if you use an amp that has some headroom left in it when you get it up to the level you desire.

 

[museav]

2 8 ohm speakers would pull 4 ohms on the amp. In stereo mode you want to look at the chart for stereo 4 ohm. That will be your max watt rating.

Two 8 Ohm speaker wired in parallel would be a total 4 Ohm load, however two speakers wired in series would be 16 Ohms. While two speakers being wired in parallel is much more likely, how multiple speakers are wired will affect the resulting total impedance.

As far as potential damage, that is really a matter of how you run the system. Pushing speakers beyond their capability can result in damaging them but so can pushing an amplifier beyond its capabilities in order to try to get more than the system can deliver. You should be okay provided that no one tries to get more from the system than it can provide and it is operated within its limits.

 

[Amiers]

So I finally got a chance to hook up everything and it sounds really nice but, After daisy chaining all my amps for the life of my I can't get my subs to work now. I basically have the same setup as I did with 2 amps so I am a bit confused. (I cant find any pictures to describe what I have hooked up so I will try to explain it with words.

AMP 1

Input A
Mixer In

Input B
Mixer In

High/Full Range A
Out to Amp 2

High/Full Range B
Out to Amp 2

Amp 2

Input A
Amp 1 A

Input B

Amp 1 B

Low Pass B
Amp 3 input 1

Before I introduced the middle amp I had the subs working just fine. and both CPX amps are set the same as I set the second one to match the first. I will take pictures later today when I get in the booth.