Bi-Amping question...

Ok gents...got a question for those knowledgeable types out there...

I'm eventually looking at the 950/770 combo. However right now I'm running an Integra 6.3 with a paradigm monitor setup (cc370, M-11 mains, M-3 surrounds) My question is this: 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. (Yes the 11's are bi-wireable/bi-ampable). The reciever is rated at 100w/ch. The 11's are rated for 15/250w and have a rating of 94db.

Any thoughts? I've read on a few sites that reccomend against using a combination of solid state and tube amps, but would the differance of 100wpc for the mids/highs and 200wpc for the bass drivers create some sort of funky responses in my speakers due to a mismatch in the amplification?

The reason why I ask is I seem to be nickle and diming my way up to seperates. I figured the two 200's would be a good start, with a 755 if I like the sound of seperates, and a pre last once I figure it's worth the extra 2k for a B&K, or the 3k for an Anthem.

Decisions...decisions...decisions.

The bottom line is I have some cash, and I'm itching to try an upgrade without dropping it all at once...because that would mean I'ld have to wait a few more months...and who wants to do that .

Jason

Jason,

I can't speak to the tubes vs solid state but the power scheme you propose is good. You definitely want more power on the bass.

I'm familiar with this from running the PA for my band, not through HT experience. My question back to you is, what do you use for a crossover or do you send full range signal to both drivers?

Did somebody say TOOBS?

The setup is actually very good having a solid state amp for the low frequencies, which needs a good damping factor, and a tube amp for the highs which can use the transparent midrange those amps provide.

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. If the amps (or one of them) have input gain pots, this is not a problem. Also be aware of phase between the two amps. Listen around the crossover frequency area and change one of the amp's speaker connections for the smoothest response.

I think to answer your question directly, no, because the 200's don't have level adjustments on the inputs so you can equalize the power differential of the Integra to the 200's. Couple this with any phase delay that might occur and you could end up with signals that are out of phase and over powered on the lows. Of course, there are devices that can phase correct and level set the input for you, but they will not work in these set up because if you needed to delay the signal, it would be the one your powering off the Integras and since the signal path is longer thru the 200, you need to delay the Integra path.

The phase may not even be apparent, but the signal level adjustment I would bet you will notice and want to be able to adjust. Your better off either finding a way to adjust the level of this signal and try it out that way. With the return policy on the 200's, give it a shot, your only out the shipping costs to send it back.

Well if it were me, I would use the 200's to power my mains full range and use the lesser powered amps on your center and surrounds. oh yeah, that is what I am doing.

Biamping can become very frustrating when you have to deal with matching levels and delays.

I would concur with morphsci -- bi-amping with different amps for low freq and high freq has the potential to be a real headache. A pair of 200's would drive your Monitor 11's with power to spare (I'm driving a pair of Studio 60's bi-wired to a Model 750 amp -- 165W each gives them all they've ever needed for me). A 755 later would round things out nicely.

------------------
gonk -- Saloon Links | Pre/Pro Comparison Chart | 950 Review

I don't agree this setup being too difficult or impractical.....the only thing to be aware of is the possible level difference between the two amps, but as I said, if one of the amps has input level controls, they can be made equal in level. If both amps lack input level controls, it's always possible to add one to one of the amps. As for phase, they will be either in phase or out of phase with each other. This can be remedied by simply swapping the wires around on one of the amp's speaker connections. There is no "delay" between the differing amp's circuits that is of any practical significance. The difference between 100 watts and 200 watts is only 3db, which is actually very little in audible terms. Having a more powerful amp for the lows than the highs is actually standard practice.

One of the beauties of bi-amping is exactly that ability to match the best amplifier for the job to it's respective frequency range.


[This message has been edited by soundhound (edited February 02, 2003).]

Well...

By the sounds of it the smart thing to do is get a pair of 200's and start tinkering. Either way (bi-amping...or just running the 11's with the 200's as opposed to the Integra) it seems that the 200's may be an interesting addition to my system.

Thanks for your advice...and if anyone else has anything to add I would certainly appriciate it.

Jason

IMO bi amping w/out benefit of an external crossover will generally be pretty pointless. There is a thread in the 1050 zone (IIRC) on this as well.

Charlie:

I agree with you on this, but using two different amplifiers of different topologies such as SS and tube should yield at least some benefit. I do think using two identical amplifiers to do passive bi-amping is very pointless, only adding complexity with no benefit.

Yeah, or if the speakers are insanely bad loads, or maybe a few other cases, but generally (IMO) a huge waste of time, money and wire. I know - the above is far fetched and not the best solution, but I'm grasping at straws to try to justify something I'd never do.....

As always, YMMV. :-)

[This message has been edited by charlie (edited February 02, 2003).]

Charlie & Soundhound

Thanks for clearing the external crossover thing for me. When reading about bi-amping in the HT world I could never understand why someone would go through the trouble without a good external crossover (or several of them!)

Biamping with a "limited" crossover between the pre and power amps is a possibility.

By "limited" I mean just using a capacitor and resistor configured as a low or high pass filter at the input of the power amps and still using the passive crossover between the amp and the drivers.

For instance, lets say that the woofer crosses over at 500Hz to the midrange.

For the woofer amp, select a value of R and C to effect a lowpass to the input of the woofer amp at a couple (or three) octaves above 500Hz.

For the high range driver(s), select a value of R and C to effect a highpass to the input of the highrange amp a couple (or three) octaves below 500Hz.

The passive crossover between the amps and the drivers will still be the determining factor in regards to the spectra received by the drivers. The passive crossover at the amp's inputs will provide some out of band frequency limiting to the amps.

Depending on the power amp's input topologies, the high pass amp may need to have only a capacitor placed in series with the input. The low frequency amps may already have a capacitor, placed after a series resistor, to limit the ultrasonic response of the amp. Increasing the value of this capacitor to a suitably large value will then provide the low pass function for the low frequency driver amp.

This setup is a viable and more affordable alternative to having an active crossover between the pre and the power amps.

Paul

------------------
the 1derful1

At that point why not do the same thing with an active crossover?

Using a single pole crossover such as this might pose a danger to the tweeter if it cannot handle the lower frequencies that would be passed by a 6db per octave crossover. If I were going to use the passive route (I actually do for my front center speaker, before the power amps) I would use a two pole inductor/capacitor/resistor filter which would yield a slope of 12db per octave, which is probably the same as that in the speaker's passive crossover.

In any event, I agree with Charlie on this however. It's a simple matter for me to fashon a line level LCR passive network, but It's probably beyond the capabilities of most HT hobbiests. I would recommend just going the full electronic crossover route. This would yield the benefit of being able to select the crossover point to achieve best response.

if you go to partexpress.com, they have on their site very informative materials on how to build your own 6, 12, or 18dB filter for various frequencies and either low pass, high pass, or band pass. I used them back in the day and found their kits the most effective for the price. A much lower cost alternative to active crossovers. Just another thought.

In my post I am still keeping the passive crossover between the amps and the speakers. The first order passive crossover between the pre and power amps was to remove some out-of-band material from being amplified by the amplifiers.

For someone who has the time and inclination, what I suggested can be a satifying and cost effective route.

I agree that an active crossover would be probably the "way to go" execept for those who can't or won't afford it.

Paul

Ask a simple question.....

I guess I should have know better then to ask a question like that on this board. Now my head is swimming...

So, to ask a stupid question...According to my manual, I just take the jumper off the back of the speaker posts. Run one amp for the low drivers, one set of amps for my high drivers. Do I need to wory about an external crossover? I thought that If my speakers were designed to be bi-wired/bi-amped that I was a fairly easy procedure to work with.

Is it, or am I completly missing something in what I've been reading in my manual (and that issue of What Hi-Fi? that I picked up).

Jason

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

You are right. All you need to do is to remove the jumper on the speaker and connect one amp to the highs (presumably the tube one) and one amp for the lows. You will need to "Y" the output of the processor to the input of the two amps. Remember, you may (probably will) have to balance the output of the two amps, but this can be done by ear, especially if you are fimiliar with the way the speakers should sound. Good Luck!

fmcorps, you might want to look here for Paradigm's thoughts on this subject- specifically Q12 and Q13. Best wishes.

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



------------------
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?

What I'm using is strictly the reciever as a reciever. I want to "work into" seperates, and thought I'ld dabble into going into seperate amps for my mains, and using the reciever for the center/surrounds.

But then I started wondering if I could use the Reciever to run the highs, and the 200 to run the bass drivers. A poor mans solution to testing out the merits of bi-amping? A crazy mans idea for creating a lot of headaches? that's the question I'm trying to solve.

So...here's what was running through my mind:

________________________
|...................................|
|Integra 100 WPC Reciever|____ Hi's
|...................................|
--------------------------
.....|
.....|
________________________
|.................................|
|......Outlaw M200 (pair).....|_____Lows
|..................................|
--------------------------

That's the question. I'm begining to assume that it's just smarter to run each apeaker off of the M200's.

Jason


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

What you have can still be done, but you would need to have "pre-out" and "power section in" jacks on your receiver: a loop through arrangement in other words. This is in case you need to lower the level of only the receiver's power amp section relative to the 200. In any event if your receiver does have the power amp input jacks also, you would "Y" the "preamp out" jacks to both the input of the receiver's power amp section and the input to the 200. You would then just need to insert the outboard volume control into the line of whichever power amplifier needs to be turned down in order to match the levels between the highs and lows. This would be done at the "Y" jack if you need to insert it into the Integra's power amp line, or at the input jack of the 200 if that amplifier needs to be lowered in level.

This is really not nearly as complicated as it sounds in writing

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

Well it looks like I'll just have to go with either a straight run, or bi-wiring my speakers, because I'm fairly certain that my reciever isn't that sofisticated.

Oh well...still looks like I can fidget with things...

Jason

Fmcorps,

Yup! to what soundhound said. You would need preamp out AND poweramp in jacks so that you could insert a high pass circuit in order for you to (optimally) use your receiver's power amps stage as an amp for the highrange section of your speakers.

You could still allow the the reciver's amp to get a full range signal and rely solely on the passive speaker crossover. This will mean that the receiver's amp will be somewhat wasting itself amplifying low frequency signals that will not reach the speaker drivers.

An alternative is to have someone modify the receiver to:

1) Add or modify the value of a signal coupling capacitor so that the receivers amp is not getting unwanted low frequency signal.

or

2) Break the connection between the preamp and power amp stages and add power amp input connectors on the back of the receiver chassis.

Either of these actions will void any warranty.


Paul

Paul,

I dont want to modify the reciever itself, as I was hoping to sell it when I decide to make the move into the realm of seperates (which I'm hoping to do within a year or two.)

So it looks like i'l have to dabble with external amplification, but leave bi-amplification alone for a little while.

Oh well. It should still be an interesting time.

Jason