Crown xTi questions

Medford Bassman · #1 10-17-2011, 09:02 AM

Hi, I'm having difficulty with my xTi 6000 amplifier. I use it exclusively to power (2) EV T-18 subs. The sub signal is AUX fed to a crossover set at 100hz then into channel 1 of the Crown. I have the Crown set in the Sub-bridge setting which allows one input but is fed to both internal amps.

The only sound coming through the subs is my bass, kick drum, floor tom and maybe a lower tom. I try to carefully set the input gain on my A&H board so I never send a clipped signal from the board. I always double check the signal after EQing just to make sure.

However, throughout the night I will see the clip red light flash intermittingly on the Crown. I rarely can get it to stop short of turning down the gain on the board or bring the slider way down making the drummer unhappy because we lose the thump from the sub.

I should note that I have the Crown Amp tuned up just shy of max, probably a click or so down.

My questions are this, should I turn down the Crown amp top about 3/4 and bump the AUX control so I can get the thump and it that the proper way to get the amp from clipping?

Sorry if it's a noob question, running sound was thrust upon me and I'm still learning.

TimmyP · #2 10-18-2011, 06:28 PM

On the XTI and iTechs, it's very easy for the input section or DSP to clip ahead of the output section. I don't know if the clip lights reflect this. You need to monitor the DSP on your computer to see what's going on.

Medford Bassman · #3 10-18-2011, 08:26 PM

Quote:

Originally Posted by TimmyP

On the XTI and iTechs, it's very easy for the input section or DSP to clip ahead of the output section. I don't know if the clip lights reflect this. You need to monitor the DSP on your computer to see what's going on.

I'm sorry for being stupid about this, I don't know how to monitor the DSP on my computer as the XTI and my computer aren't linked. I don't bring a computer to the gig.

walterw · #4 10-18-2011, 08:32 PM

is there a high-pass setting in there somewhere to kill anything below like 40Hz?

be sure that's happening, and you'll get more leftover power from the amp for the rest of the low end (where it's needed).

also, the occasional clip light flashing usually isn't that big a problem with subs.

uhdinator · #5 10-18-2011, 08:39 PM

Compression inserted on drum tracks will allow you to get more volume while controlling peaks. Doesn't hurt to compress bass also.

Let's see. 2-8 ohms cabs rated 1600 peak. They should have around 800w each. An XTI 6000 in stereo mode is 1200 per channel at 8 ohm. That is a little more power than needed but works if you don't clip the amp.

However. If you have it bridged as stated it produces 6000w at 4 ohms. And the speakers are connected differently. So your are running almost 2 times peak power into each sub if your speakers are wired to the 2 positive posts from channel 1 and 2. (when you bridge an amp you don't plug one speaker into each channel) I suggest you read/learn about bridging.

I suspect you are in bridge mode with the speakers wired wrong. you need Y mode. Input ch1 is sent to ch2. run one speaker each side. set crossover at 90-100. A computer is required to set up crossover the same on both channels otherwise the default is sending high freq to channel 2.
Limiter can be set at -3 -6 or -12. Computer needed to create your own preset. Once it's set and saved no puter needed.

These issues may be contributing to clipping.

Gizmot · #6 10-18-2011, 08:51 PM

The setting of the input level control means nothing. The amp can still deliver its full rated power if you had the gain control at the 9 o'clock position - the only thing you're changing when you raise and lower the control is the amount of voltage required to drive the amp to full output. Modern switch-mode power supply amps like the Crown don't have as much headroom as amps used to when they stored energy in banks of capacitors.