to biamp or not to biamp

L

LiamSmith

Freshman
Jun 5, 2012
83
0
6
Ulster, NY
I am powering a pair of qrx212 with an XTI 2000 in stereo mode. I do currently own a second xti 2000 that's just sitting around. Would it be safe to biamp my 212's with the second xti? Or should I bridge one 2000 into each passive? Or just keep things as they are?

I had heard there are some real advantages to biamping the 212's, but I have never done it before.
 
Re: to biamp or not to biamp

Bennett Prescott wrote a wonderful article on powering loudspeakers that you can view here. The most important thing to get out of it is that- yes, you can. But be careful and do the math before trying it. I would try to explain some more, but I would prefer if a more experienced member explained this one as I am rather inexperienced in this area.
 
When I bought my 212s (used), the sellers both strongly suggested I biamp them.

So, I got a DSP and got settings for it (how I got them is an interesting tale for another time). Meanwhile I ran em full range.

When I fired them up in the biamp config I was stunned. Different beasts. Much nicer.

I use QSC amps so I can pretty much put any of my PLX amps on either the HF or LF as long as the DSP was set right. I use a PLX1602 for the HF and a PLX3402 for the LF.

I understand that you need to set it up a little differently with Crown amps but know not about the details. I am sure there are folks here who can sort it out.


Sent from my iPad HD
 
Re: to biamp or not to biamp

The real difference will be in how the digital processing is set up. Done right it is a completely different animal as Rob mentioned. It is not just a crossover point and filter slope but also time alignment, some frequency smoothing, and usually some voltage limiting. Also if done digitally there aren't all of the phase issues from the analog crossover. The difference is not subtle. Speakers are the weakest link in the chain so a drastic improvement here is much more noticeable. A little costly when you figure the price of the processor and extra amps and cords but usually money very well spent.

If you are unable to get the the processing done yourself or find a blackbox setting for those cabinets I would say it is worth it to hire someone like Phil Graham to do the set up and also to recommend the best and most cost effective processor. That is almost a field by itself and after over 30 years in sound reinforcement that is one of the few things I still hire out if there are no factory settings for a particular processor, amp, and speaker set up.
 
Re: to biamp or not to biamp

Eric Cagle said:
Also if done digitally there aren't all of the phase issues from the analog crossover.
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Not necessarily. Not only may those "phase issues" be part of a tuning but IIR digital filters also exhibit frequency dependent phase shift. FIR filters can be linear phase but may have other tradeoffs such as the related delay for lower frequency applications. Just an example of why the speaker processing tools available may be more capable than ever but applying those tools effectively can require relevant understandings and skills.
 
Re: to biamp or not to biamp

Brad Weber said:
Not necessarily. Not only may those "phase issues" be part of a tuning but IIR digital filters also exhibit frequency dependent phase shift. FIR filters can be linear phase but may have other tradeoffs such as the related delay for lower frequency applications. Just an example of why the speaker processing tools available may be more capable than ever but applying those tools effectively can require relevant understandings and skills.
Click to expand...

Exactly, especially the part about relevant understandings and skills. I understand enough to know I will leave the settings to those of you who do currently understand and have the skills necessary to properly set up all that is involved.
 
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