BillFitzmaurice.info

hey BFM,

I'm in the process of completing 2x omnitop 12's (3012HO) and 2x T60 "slims" each loaded with a Lab 12.

I currently have a single QSC RMX 850 , 2ch / 200w per channel @ 8ohms.

I understand I can "get by" using this amp for the tops but its far from ideal.


Everything i've read suggests having more watts per channel than the max rms of the driver for "headroom".



My budget is around 2k.

I want to go with the QSC PLX2 series. (why is the 1804 cheaper than the 1802 ??)

And also get a dbx DriveRack PA+

Besides cables , I should be all set ??

Unless you have an issue with Crown amps, an XTi4000 is right up your alley. Plenty of power and no need for external DSP. This will leave more money in your pocket.

Hey Phatman,

QSC is the only company I have any experience with really and from what i've read they're rock solid with great warranties.

I've read good things about crowns and bad things about crowns so ... I guess i'll have to do some more reading

thanks for the suggestion

EDIT:

Did some google searching and they seem like a good deal ; if I would need only 1 but...

The picture on proaudiostar shows only 2 speakon connections on the back so would I need 2 of these amps ... ??

what am I missing here? 4 cabs , 4 speakons ... right?

You can daisy-chain the cabs. Build each cab with 2 speakons, one jack is 'In" and the other is "Through." They're simply parallel wired inside.

This means running mono and paralleling the two tops on one channel and paralleling the subs on the other. Personally, i prefer mono for gigs but if you must run stereo, two amps are necessary.
.
But yeah, the xti4000 seems like the bee's knees for your set up.

What are the benefits of running them mono, besides only running 1 amp?

It seems to me that I would be better off with two amps so that they're dedicated to highs and lows and have plenty of left over head room ... ??

metaverse wrote:What are the benefits of running them mono, besides only running 1 amp?

It seems to me that I would be better off with two amps so that they're dedicated to highs and lows and have plenty of left over head room ... ??

Modern amps are essentially voltage sources. As long as you are within rated power and impedance, there is effectively no difference in running two drivers on one amp or one driver each on two identical amps. Remember that each "amp" is actually two seperate amps.

The only benefit to running stereo is panning capability. This is sometimes helpful live if you're trying to get more gain out of choir mics, if you need a stereo effect, or have some other valid reason to need to seperate the signals... but in many live audio situations you have to run mono as most of the crowd will only get coverage from one stack.

And to add....
An amp such as the XTI4000 has built-in DSP which means that one channel can be sub-only and the other channel can be top-only.

Thanks for education