Jump to content

Help me engineer my sound system.


Recommended Posts

  • Members

The power for your tops will probably be a little light, but they'll still outrun your subs. You'd probably be best to buy another amp for your tops, and another set of subs with an amp, but that's getting into quite a bit bigger rig. What you've got should work OK, depending on the area and people you're trying to cover, and the type of music you're doing. It seems like it'll be a nice sounding rig.

 

Be sure to set your limiters correctly, especially on your HF amp.

Link to comment
Share on other sites

  • Members

You need to understand the specs of your tops a little better before making the assumptions you made...

 

1. The continuous rating of the 215 box (LF section) is 800 watts "RMS", 400 watts per driver. Each driver is 8 ohms, the nominal impedance of each 215 LF section is 4 ohms and with 2 boxes per channel that's 1600 watts at 2 ohms not 3000 watts. For this, the I-TECH 4000 is perfect.

 

2. The 2000 watts per QRX-218 is kind of high however. I would recommend around 1200 watts per box and that's with a 35Hz HPF, 24dB/octave BW. I have reconed enough of those drivers to say that while I love the sound of it, they are not the robust mechanically and a little bit of "conservative" goes a long way.

 

3. Your HF driver is good for about 80 watts continuous (give or take) but properly protected, powered at 200 watts per driver (400 watt per box) is fine. Do you have a way of limiting the XTI down to 400 watts/channel at 4 ohms?

Link to comment
Share on other sites

  • Members

Thanks for all the good comments.

Can you provide me some recommendations on how to set up my limiters on this rig?

Also, I am glad to hear that the ITECH-4000 will be perfect to run all 4 tops at 2 Ohms. Should I be concerned about triggering the circuit breaker. I heard that the ITECH can draw high amperage when running at 2 Ohms.

I also like the idea of setting a high pass filter on the subs at 35Hz. I can do it with the using the DSP inside the ITECH-4000 powering the SUBS.

Link to comment
Share on other sites

  • Members

What are you using for crossovers? The processing in the amps? If so, set the limiters in the amps at -2dB below rated output on your subs, this will help in the event of an unfortunate "accident" Set your limiters in the XTI to -3 or -4dB for HF. You may have to use SA to get to this control. I'm not a Crown guy so I'm not as current with what you can do via front panel control versus SA or BM.

Link to comment
Share on other sites

  • Members

If I am wrong, I stand corrected in advance.

 

Regarding the suggested amplification for your U215 LF section, Yorkville recommends 1,600 watts per U215 cabinet @ 4 ohms (or 800watts/prg per 8 ohm 15" driver). That means the LF section of (2) U215's will require amplification on the order of 3,200w @ 2 ohms. With that, your ITECH 4000's 1,800 watts @ 2 ohms equates to RMS/continuous power; not program power. I'd be concerned the ITECH4000 will not have the headroom you will need/want.

 

I have a large Unity rig myself (6 U15B's and 6 UCS1B's) and when I put the system together Yorkville indicated I should provide "as close to" 800 watts to each U15 LF driver. Taking note the U215 has twice the number of LF drivers, 1,600 prg @ 4 ohms is what I come up with, or 3,200 watts/program for (2) U215's - 2 ohms.

 

ScottH

 

BTW: I wound up powering my U15 LF with QSC PLX2502's (stereo) - 750w/ per driver. I use the dedicated U15 processor.

 

Hope this helps.

ScottH

Link to comment
Share on other sites

  • Members

cThe U215 crossover/processor has filters and HPF's and correcton eq but no driver limiting protection so it's really a simple device.

 

I have reconed quite a few Yorkville drivers, nothing at all wrong with them but I would recommend powering around the RMS rating as they do in their powered speakers (actually it's a bit more complicated than that because of their limiting algorithems). Power compression robs much of any gain you will hope to achieve with more power and reliably falls of pretty quickly if you do need to drive them that hard.

Link to comment
Share on other sites

  • Members

To the OP - I use the U15 tops, one per side. I know that Yorkville says to power at twice the RMS, or at equal program power, but I think 1.5x RMS is the max you should go, probably safer to power at RMS. I have powered at twice the power but I'm a safe freak, to the point of being boring.

 

Re: the processor, I've tried many times to like the UP15 processor (as recently as two days ago) but I just don't. I've had better success using a Driverack. I like having more control of xover parameters and limiting (as well as GEQ and PEQ) doing it that way YMMV.

 

However if the processor works for you, don't go changing.

 

Anyway I'd love to hear that rig, hope you have fun with it.

 

EDIT - as AH has mentioned all of Yorkville's speaker ratings are in program power, so it's eyes open when working out your powering scheme.

Link to comment
Share on other sites

  • Members

 


3. Your HF driver is good for about 80 watts continuous (give or take) but properly protected, powered at 200 watts per driver (400 watt per box) is fine. Do you have a way of limiting the XTI down to 400 watts/channel at 4 ohms?

 

 

The -3dB setting on the XTI internal limiters would handle this problem?

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...