Biamping - what would give better results? (1 Viewer)

[amatala]

Hello,

I am currently considering bi-amping my fronts but I am not sure if two medium-powered amps in a biamp setup would give better results than a single higher-powered amp.
To be very specific, when using amps of the same brand and same construction, would it be better to use two amps of 2x45W to power the fronts in a biamp config or it is better to stick with only one amp of 2x100W in a 'normal' single amp config?
I currently own 2 H/K PA2000 power amps which can work as 2x100W in bridged mode or 4x45W in non-bridged mode (which would allow me to do biamping). So ... which way, which way?

Any comments are welcome!

Thanks!

 

[John S]

Here is an excellent article about what true bi-amping gives you.

http://www.sound.westhost.com/bi-amp.htm

I think there are some serious misconceptions here about it.

 

[VinhT]

Adrian,

Bi-amping will most likely result in degraded performance. Why? Off-the-shelf active crossovers with generic slopes are unable to match the versatility of custom passive solutions.

It actually sounds like you are asking about bi-wiring. For the average enthusiast, I feel this would be a better choice than bi-amping because it maintains the integrity of the crossover. Since you already have the amplifiers, just go ahead and try it to see if you like it better.

 

[John Garcia]

He's talking about passive biamping vs active biamping. Passive biamping being separate power amps for each terminal, using the speaker's passive x-over.

Bi-wiring will give you the same result as just using a larger wire gauge; nothing more.

IMO, go with 2x100.

 

[Michael R Price]

If you can do it right, active bi-amping is the real deal. Even with "only" 45 watts per channel. However, doing so is usually not worth the trouble. Adrian, did you have a particular crossover setup in mind?

 

[amatala]

Hello,

I had no particular x-over in mind. I am currently using the amps in 2x100W bridged mode, bi-wired to the speakers. I was wondering if switching the amps no non-bridged 4x45W mode and using passive bi-amping would make a difference.
In both cases the x-over would be the same: the one in my speakers.
I know I could just try it but I don't want to start moving my amps around and switching cables again if everyone thinks it's not worth it!

Thanks!

 

[Michael R Price]

Adrian,

In my experience passive bi-amping lets you mix the sound of two amplifiers: so if you had a small Class A amplifier it would be useful to use it as a tweeter amp along with your PA2000's for woofers. When using identical amplifiers, it doesn't seem to me there would be much benefit... but hey, why not give it a shot anyway! In contrast, I would definitely expect an improvement in switching to active bi-amping even with the reduced available power.

 

[John S]

Get some electronic crossovers, and give the real deal a shot. The difference has always been dramatic in my experiences.

 

[Chu Gai]

It's doubtful that passively biamping your system with two lower power amps per speaker, let's say each are 50 watts, as opposed to giving the speaker the full 100 watts will result in any benefit. In fact, you might even be underpowering your speakers.

Although the audible spectrum is taken as 20-20kHz, the amount of information is not uniformly distributed across the spectrum. Very roughly, it is proportional to 1/f. You'll find that the link that John S provided makes mention of this at http://sound.westhost.com/bi-amp.htm#power_dist Therefore, depending upon your crossover, you might only be needing somewhere around 20%, give or take, of the available power. However, the lower frequencies will need what they need. Consider the following Q/A from http://sound.westhost.com/faq.htm#bi-tri which states,

Well, yes Michael but with unpredictable results. Off to the Iron Chef Audio competition. Seriously though, precious few have invested the time to take the approach that you have nor have they been as systematic with their measurements. Off hand, have you ever considered summarizing your work with graphs and schematics in one place and then making a post over at rec.audio.tech to see if you'd get some feedback from professional speaker designers?

 

[Michael R Price]

Chu,

I have had the active crossover page up since last summer and I've posted it here and at some other forums, but I haven't posted it on newsgroups. So far, one other person is building a crossover using my design. I wonder if that speaks more about the very specific nature of my project, or just the general attitude that the active filters are not worth the bother.

 

[Chu Gai]

Tough to keep track of everything. I'll leave it to you if you want to post that link over in the newsgroups. Me, I'm simply curious to hear other responses. 'Course, it'd probably mean more work for you!