Paradigm's Q&A 13:

Q13... When Bi-amping, can I use different models of amplifiers?

A... While this can be done, it is generally not a good idea...

I think that Paradigm's answer to Q13 might be valid for someone who knows nothing about audio or elctronics, but for someone who does, their answer does a disservice to the user.

A better answer, IMHO, is "Yes, it can be done and done with good results if some simple precautions are taken."

The level matching precautions are then stated.

Paul



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the 1derful1

Thanks, Paul for posting this - I was going to say basically the same thing.

I would add that using identical amplifiers for the highs and lows does away with the one most useful benefit of doing this, that of matching the amplifier to the range where it will do the most good.

Paul-- I must respectfully disagree with your above post- somewhat anyway. I can see that, due to yours and Soundhound's expertise, Paradigm's stance on bi-amping does not apply in all instances- particularly in both your cases. But in this case, the manufacturer has to address what they feel is the capability of the average user of the product. Going back to Jason's original question, he said: "Can I use two 200's to bi-amp my mains by having the reciever run the "high" drivers, and the 200's running the bass drivers in the 11's." I believe neither his receiver nor the M200's would allow him to level match the way Paradigm says they would like to see it done- IF you bi-amp with amps of different manufacture. I believe Paradigm does answer Jason's original question correctly in this case. I think alpanstein, morphsci and gonk were saying the same thing, but somehow the thread turned into a discussion on external cross-overs as Jason's point: "(Yes the 11's are bi-wireable/bi-ampable)." possibly missed. (IE the speaker has 4 posts with jumpers for bi-wiring/bi-amping). IMHO, I believe Soundhound did provide the correct response to all this when he said: "The only thing I would watch out for is that if you are truly doing 'passive bi-amping' by keeping the speaker's internal crossover, the amplifier's gains must be the same or the high-low frequency balance will get altered." And you're right Paul, Q13 probably was written with me in mind!

I try to keep the point of view of someone without a particularly technical background in what I say, sometimes I'm successful, sometimes not

I do believe that HT enthusiasts are becoming less willing to "draw that 'ol soldering iron from the holster and shoot it" in Outlaw-speak. Getting into the "guts" of some of the equipment can be a rewarding experience. Hi-Fi used to be this way back when it was something new and exciting, but the increased "packaging" of components seems to stifle the urge to do some real customizing. Manufacturers in particular want to keep iron-clad control on what people try to do with their products. While I don't recommend opening up your electronic components unless you really know what you're doing, there are a lot of projects that can still be done.

Speaker projects in particular can save some real money, and provide sound as good as or better than "store bought". It's simple and there are real rewards to making one's own interconnects, for example. I guess I was alluding to this spirit of do-it-yourself-ism with the suggestion of adding a level control to amps that lack them, so that disimilar amps can be matched in output (the level control could be made in an external box). Starting with simple projects, people can, with some thought, achieve more than the sum of the parts of their system, with some well thought out customizing.

So tin-up that soldering iron partner, and have some fun........


[This message has been edited by soundhound (edited February 07, 2003).]

Paul, thanks for the information, that's what I was getting at. I read one place that yes, you can just hook up one amp to the lows, one to the highs, and there you go. I read in my speaker manual the exact same thing that Paradigm states on their web site...and I start scratching my head. I've never bi-amped before (have tried bi-wiring but havn't been completly convinced that it improved the sound).

So, next question is, if I need to create some sort of gain control, where do I go to find some background and instructions to do so? I'm willing to spend some time money and sweat to give it a shot...I'm courious as to what would need to be done.

Jason

Jason:

Radio Shack is a pretty good place to go to pick up the required materials and they undoubtedly have books that cover projects like this. For the level control you would basically need a couple of 10K ohm (this can range from 10K ohm to 50K ohm - it's not critical, but 10K ohm is preferrable) audio taper potentiometers (one for cach channel). Also you will need an aluminum project box to put them in, the input and output RCA jacks, shielded wire, and a couple knobs of your choice. You could purchase a couple interconnects and cut them in two for the input and output wires, so the RCA plugs would not be needed. The important thing to keep in mind with these outboard level controls is to keep the length of the output to amplifier interconnect wire to about a foot or less. This is because if it is too long, the capacitance of the cable will cause a rolloff in high frequencies. If the length is kept to a foot (or less) then there is no danger of this happening.

OK hound, next question.

Is ther any way I can check the specs of my reciever to the specks of the 200 to see if they would be "in the ball park". If so what should I look for, and what should I go off of for a "ballpark" estimate.

And just to make certain I'm understanding what the heck I'll be makeing...I'll basicaly be building a little black box that will adjust the signal volume going out to the bass drivers? Or am I completly in the dark here and missing the point entirely?

Jason



[This message has been edited by fmcorps (edited February 08, 2003).]

You are making a volume control to lower the volume of the amplifier that is basically too loud. This might be the one for the bass, or possibly the one for the high frequencies. In any event, the volume control would be inserted before the input of whichever amp needs to be turned down in order to achiever proper level balance between the highs and lows. The neat thing about making the level controls in a separate box is that they can be used for either amplifier.

In the remote possiblilty that your tube and solid state amps have identical gains, you would not need the level controls at all, but I am pretty sure you will.

In the unlikely event that you can't find the proper way to wire the level controls, here it is:

Hold the control with the shaft facing you, and the three terminals pointing down. As you look at the control, the terminal on the right (the clockwise direction of rotation of the control) is the input side which goes to the 950 or whatever your source component is. The center terminal goes to the input to your power amps, and the left terminal gets the shield wire from both the input and output interconnects.


[This message has been edited by soundhound (edited February 08, 2003).]

Ok..just to clarify,

I was thinking of using the using the internal 100 wpc from my integera to run my hights, and the 200 as an external ampliffier for the lows. The reciever I have has pre-outs...and that's why I was pondering the bi-amping question.
Is that completly out of the question? Am I foolish for pondering this at all...

Questions...questions...questions

If you are using the receiver as strictly a power amplifier, the volume control on the receiver can act as the "level control" for that amp. Then, you would not need to construct the outboard level controls since you can use the receiver's volume control to control the volume of that amplifier. The only thing you would need to do is to buy a "Y" adapter, and route it to both the input of the 200, and a line input of the receiver, ignoring the "pre-outs" of the receiver.

I'm assuming you are using another preamp like the 950 or something similar for the main switching and overall volume duties?