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Question about byamplification

Hi guys

A question for those with experience and knowledge.

 

I'm thinking about experimenting on byamping with my valve amp, the Line MagneticLM-508, and a class D power amp I have, both driven by my Audio-GD HE-1 preamp.

 

As my speakers, the Q Acoustics Concept 500, have two pairs of binding posts, I was thinking about connecting the LM-508 to the highs binding post and the class D to the lows ones of the speakers.

 

I don't have an active external crossover, so I was suggested on splitting the RCA output of my preamp to both amplifiers. I know that I will probably have trouble matching the gains of the amps as they are likely different, but I have tubes with different gains and also the LM508 has a knob with different negative feedback settings (different gains) so I can try to match them, at low volume levels of course.

 

The one millon dollars question is if I'm risking on blowing a tweeter with the LM-508? The speakers manufacturer said I should be careful since the LM-508 will only be running the tweeters and it could "see" a high impedance load at frequencies below the crossover point (2.5 Khz).

 

On the other hand, people with experience on byamping told me that it should not a risk, I should only start with low volume levels and go up carefully.

 

Has anyone experienced something similar? Am I risking the tweeters or the amps?

 

Any thoughts or suggestions are appreciated.

plga

Showing 3 responses by russ69

russ69's avatar
russ69
3,360 posts
 

Get a crossover. The DBX is a very affordable unit and works great. Model 223XS. I run a similar unit on my big system and it works good and solves all crossover issues. 

russ69's avatar
russ69
3,360 posts
 

I guess external crossovers are for speakers without internal crossovers. Am I missing something?

Setting levels for two different amps.

russ69's avatar
russ69
3,360 posts
 

So, what’s the point on adding an external crossover if I won’t be able to change the crossover point at the end of the chain. I guess external crossovers are for speakers without internal crossovers. Am I missing something?

A bi-amp or tri-amp systems are a big-boy playground. There are a number of reasons to use a proper crossover even on a loudspeaker that has an internal crossover. Most have already been discussed. A proper crossover will give you flexibility that a mere volume control can't do. You can affect the built-in crossover to some limited extent and you can simply bypass the internal crossover for full control. Running both amps full range is eliminating one of the reasons to bi-amp in the first place. There is a difference between being ABLE to do something and doing something the right way. If you are going to all that effort to bi-amp you should want to get the maximum out of that configuration. 

OK, I said my piece.   

 

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