Amps-speaker matching, bridging??
Home > Home Recording Forum > Live Sound Reinforcement > Amps-speaker matching, bridging??
Posted on May 25, 2009 10:49 pm
SOcRatEs
Socially inept
Member Since: May 25, 2009
Deleted By SOcRatEs
[ Back to Top ]
SOcRatEsSocially ineptMember
Since: May 25, 2009
May 27, 2009 01:47 am Hello,
I'm Greg,
System used for acoustic and speaking engagements.
I've never run an amp bridged mono.
What is the best configuration for these speakers and amps?
Thanks for any help!!
System is:
furman
8 channel soundcraft
dual channel eq
m300 fx
4 channel multi com
Speakers:(?) I don't now if this is program, rms or average.
EV Eliminators
2 x eliminators i- single 15"
350w 80hm(?) peak 1400w 8ohm
2 x eliminator i sub- single 18"
400w 8ohm(?) peak 1000w 8ohm
Speakers can be run in parallel= main mix to subs passes thru to mids, making this a 4ohm load?
Amps:
Crown
XLS 402
300w 8ohm- 450w 4ohm
bridged 900w 8ohm- 1140w 4ohm
Crown
XTI 1000
275w 8ohm- 500w 4ohm
bridged 1000w 8ohm- (1400w 4ohm (1% thd (kinda high!)))
May 27, 2009 01:17 pm Does your sub have a passive crossover network that has a high pass output?
If it does, then you are correct on the total ohm load. It should be 4 at that point.
The Turbosound TXD series does the same. and that is how we run them from time to time.
The thing that I would do, is to run the Crown XTI 1000 on the subs. Put it in bridge mode, and low pass the output of it from the DSP in the amp. That way you can set the delay time as well.
Although, for speech, you really can leave them at home. Not to many people need subs to their voice.
The top boxes, the XLS is fine in stereo mode. I don't think that you need to do any fancy wiring to them.
Now, when you wire the subs in bridge mode, you need to take the NL4 cable that you have, and wire it as an NL2. And here is the key. You have to wire the cable from the amp end as +1 AND +2.
So, one wire on the +1, and then the other on +2. That makes it bridge. And the amp has to be in bridge mode as well.
So, the +1 will be the positive. And the +2 will be the negative.
On the sub side, the cable will still be +1 for positive, and -1 for the negative.
Make sure that you mark that cable for subs in bridge mode only. Putting it on another amp will blow up the amp and speaker!!!!!!
SOcRatEsSocially ineptMember
Since: May 25, 2009
May 27, 2009 02:12 pm Does your sub have a passive crossover network that has a high pass output?
Yes it does...
Putting it on another amp will blow up the amp and speaker!!!!!! yeehaa!! I've yet to run any amp bridged, other than on mono monitor stage.
Thank You!!
My constraints were to work with what I still had on hand. Kinda make do situation... but with further thought,
I'm putting the xti in other system to make it a 4 monitor mix rather than just 2.
dumping the xls 402, because in 2 single 15 situations I am often asked for ambiance music.
In order to have 2 Independent systems (8 channel & 32)
I'm thinking toward 1 dual duty, amp to run single 15 & 18's in stereo 4ohm.
I think this mean I need a 1400w 4-0hm amp
May 27, 2009 02:35 pm Sounds good.
May only concern is that are you running the single 15" and single 18" at the same time?
If so, your asking for a timing nightmare!
And off a single line, you have no way to delay the 15" back from the 18"
SOcRatEsSocially ineptMember
Since: May 25, 2009
May 27, 2009 03:11 pm Phasing on my crossover DBx 2way stereo 4 way mono, is only a & b channel.
won't allow from top to bottom.....hmmm got it! I know this is not what you meant,(to delay the 15" back from the 18")
So really, for flexibility sake, 2 amps is really the way to go.. this system is proving to be the work horse for me.. max flex is direction I need to go in. The object is to have this smaller sys avail for smaller events on same day as big sys is out on bigger show.
Seems there is no 1 right way to do this, just diff ways with +'s and -'s to each...
I was thinking of listing all my components to see if I missed something. That may prove an even a bigger nightmare.(not appropriate use of this community)
My sound engineer is from the Conservatory (mostly recording) here in Az.
Came to me as intern, it even stumps him from time to time..
Thank you for all your help!!
May 27, 2009 03:18 pm Cool dude!
And should any influx of cash happen by you. May I suggest the Ashly 4.24C.
It's a little more in depth then a DBX. And will allow for more flexibility.
SOcRatEsSocially ineptMember
Since: May 25, 2009
May 27, 2009 04:03 pm Rob Stemple
Thank you again!!
I updated my profile...
