Bi-amping questions

[hewlew1 258]

In a triamp situation would it make more sense to use identical amplifiers rather than mix them up? I am planning on building a set of speakers to take to Carverfest this year that will be triamped. I have 3 TFM25's just for this project.

[LVMAN777 358]

My idea is to add a "SuperTweeter" to Carver Platinum"s...

(Tri-Amp)...with 3 M1.5t's or a Sunfire 200x7

Use the "Parts Express"  "...Dayton Audio PT2C-8 Planar Tweeter..." ($49.98)

 

 

 

 

http://www.parts-express.com/dayton-audio-pt2c-8-planar-tweeter--275-085

found in $1000 each Sunfire CRM-2's

and cross-over from the Carver Ribbons just below the 6 K resonance point

NO CROSS-OVERS AT HIGH POWER

ALL PASS LINE LEVEL FILTERS BETWEEN THE C1 Preamp and 3 M1.5t PA's  

 

200-400 watts x 6...through a fuse only 

Woofer 30-200 hz....

Ribbons 200-5,000

Super-Tweeters- 5,000- 26,000

 

What is the best PC based RTA with Mic?

 

Stereo One in /three out line level crossover ....with passive line level filtering?

[zumbini 6,153]

In a triamp situation would it make more sense to use identical amplifiers rather than mix them up? I am planning on building a set of speakers to take to Carverfest this year that will be triamped. I have 3 TFM25's just for this project.

We'd need to know more about your speakers to determine your power requirements.

In my system the tweeters draw 10-15%, mids 25-35%, and subs 50-70%. 

If I used 3 identical amps the sub would run out of power long before the tweets and mids.

[zumbini 6,153]

Did you setup the sound when you and your brother worked at Cosmic lights?

I installed and tuned the sound systems but the club owners usually decided what to purchase.

[B-Man 4,784]

 

 

I'm using 4 amps to drive 3 frequency bands. Am I quad-amping or tri-amping?  

 

You are amplifying 3 bands with 4 amplifiers.

 

 

Not criticizing or arguing, I'm just curious about your selection of amps for the frequencies you have them working at.

 

Normally, we all read that the M500t is the cat's a$$ for it's mids & highs - nice and silky smooth.

 

Most folks follow that commentary with the M1.5 is too bright or harsh, but it is an awesome sub amplifier.

 

And then the M1.0t MKII Opt 002 is usually described as a beast that sounds good, but is not quite as smooth as the M500t.

 

Question for you - everyone sings the praises of the M500t for the warm midrange and smooth highs, yet you are using them for sub duty ?? And you are using a M1.0t for the mids ?? Didn't you once have a M1.5 powering the subs ??

 

[zumbini 6,153]

 

 

Not criticizing or arguing, I'm just curious about your selection of amps for the frequencies you have them working at.

 

Normally, we all read that the M500t is the cat's a$$ for it's mids & highs - nice and silky smooth.

 

Most folks follow that commentary with the M1.5 is too bright or harsh, but it is an awesome sub amplifier.

 

And then the M1.0t MKII Opt 002 is usually described as a beast that sounds good, but is not quite as smooth as the M500t.

 

Question for you - everyone sings the praises of the M500t for the warm midrange and smooth highs, yet you are using them for sub duty ?? And you are using a M1.0t for the mids ??

The short answer is that the current arrangement is probably NOT the most sensible one (as you pointed out).

The truth is the current arrangement is based on achieving maximum SPL rather than the best sound quality. 

 

 

....Didn't you once have a M1.5 powering the subs ??

Actually I had a PAIR of M-1.5t's driving the subs, a pair of M-500t's on the mids, and an M-500 on the tweets.

 

When Zack graduated from grammar school I put together a system for him out of components I had on hand.

He choose the M-1.0t, a CT-Seven and a DTL-200MK2. I later traded him an M-1.5t so I could MKII the M-1.0t.

(Eventually I traded the 2nd M-1.5t to Kevin for an MXR-130.) 

[Nahash5150 11,011]

Active versus Passive is a complex question, only because speakers are complex. Since the speaker is at the end of the chain, the system can never be exempt from its inherent complexity.

 

With that in mind...

 

It takes great skill and knowledge to understand and apply filtering to speakers. But that's okay, that doesn't mean it's out of your grasp, it just means that you won't find the ultimate solution under your couch cushion...rather, between the pages of electronics manuals and physics texts. Get the knowledge. It's out there. It takes time to understand, but you will eventually understand it. I promise.

 

Just remember this - a driver's frequency response is EVERYWHERE but flat. Its resistance changes as a function of frequency, which changes the filtering response with it. Without measuring what comes out of your speaker with a microphone and a means to adjust the curves on an active crossover, you will be doomed to uncertainty. And I mean DOOMED.

 

So the conclusion is, if you have well-designed speakers with passive crossovers, you are fine. The passive crossovers are designed to compensate for the driver's ever-changing and renegade reactance and phase shifting. You'll lose a little power, but not enough to be alarmed about it. If you go active, then you had better be able to tell me the difference between an octave and a decade and how they roll off, and you had better be able to explain cutoff and phase shift...to start.

 

If you have muscle speakers and you want to make a wall of sound - have at it active. When it's loud, you can't go wrong. Garage Pro Audio is generally happy with a good day's work if they don't get feedback. Otherwise, for the audiophile, a more refined and knowledgeable approach is necessary.

 

So bi-amping does complicate things, but not because the amps are complex (really, they're not) but because the speakers are...and other things...

 

It's easy to believe that two amps are twice the power of one, and four twice the power of two, but there are other things to consider. What about the power delivery at your outlet? You'd be amazed how much power you lose in your house wiring with four amps connected to one circuit...I mean jaw dropping amazement. And what about those crossover points and what all those frequency bands you created are doing to your amplifier performance? For the most part, not much, but let me just say that one should take more care with the volume knob bi-amping than without. Yes you have more power, but it's limited power, and class A/B amplifiers heat up quicker under low dynamic range. Different drivers consume different values of power to produce equivalent sound levels, so sometimes, bi-amping is just overkill.

 

It really depends on the speaker more than anything I think. Know your speakers. Do you really think it matters on some cabinets that the mid and tweeter be driven by their own amplifier? A great majority, probably not. Tweeters hardly take up more than 30 Watts on the hardest of drunken kranking. Bass drivers are different. The more dedicated power the better. 2000 Watts of headroom or better for those.

 

I hope that helps.