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Bi amping

Thomas savage

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I'm thinking of getting some class D monoblocks to drive my bass woofers and using my Belles monoblocks on the mid range and tweeter.

I have two outputs on my preamp so it should be easy But are there any issues I shoud be aware of? Things like timing issues as diffrent amps being used or gain differences between my Belles and new clad d amps?

I have no clue but usually theses things are never as simple as buy 2 more amps and plug them in...

Any help would be greatly appreciated :)
 

Kal Rubinson

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Gain difference is very likely and must be accounted for by the user.
 

Fitzcaraldo215

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I'm thinking of getting some class D monoblocks to drive my bass woofers and using my Belles monoblocks on the mid range and tweeter.

I have two outputs on my preamp so it should be easy But are there any issues I shoud be aware of? Things like timing issues as diffrent amps being used or gain differences between my Belles and new clad d amps?

I have no clue but usually theses things are never as simple as buy 2 more amps and plug them in...

Any help would be greatly appreciated :)
Not totally clear on what you are suggesting. It seems to be passive bi-amping, where you are still using the passive xover in your speaker. I do not think that is worth the time and effort. And, as Kal notes, you do need some means of level balancing between HF and LF amps.

Active bi-amping is a better approach, though more complicated. But, to do that properly, you need to rewire your speakers internally to completely bypass the internal passive crossovers. The speaker manufacturer will just love that if you ever have a warranty repair situation. So, that can be problematical with most off the shelf speakers. Even if the speakers have separate HF and LF input terminals, the signal is still flowing through the passive internal xovers.

Best idea, is to leave your main speakers alone with one amp/channel and install one or more subwoofers which have active xovers, level and continuous phase controls, etc. for best integration, yet with a split of the frequency via an active xover. I do not think that subwoofers used without a hi pass filter for the main channels - mains run full range - is optimal due to phase synchronization issues.
 

watchnerd

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I'm thinking of getting some class D monoblocks to drive my bass woofers and using my Belles monoblocks on the mid range and tweeter.

I have two outputs on my preamp so it should be easy But are there any issues I shoud be aware of? Things like timing issues as diffrent amps being used or gain differences between my Belles and new clad d amps?

I have no clue but usually theses things are never as simple as buy 2 more amps and plug them in...

Any help would be greatly appreciated :)

What problem are you hoping to solve?

Are the Belles unable to provide enough output?

Or are you thinking you want some Class D 'flavor' in the bass?
 
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Thomas savage

Thomas savage

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Just wanted some class d flavour in my bass :D and take the load off my Belles .. Might be totally pointless but thought I might give it a go, as long as the 'problems' we're not prohibitive .
 
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watchnerd

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Just wanted some class d flavour in my bass and take the load off my Belles .. Might be totally pointless but thought I might give it a go, as long as the 'problems' we're not prohibitive .

The forthcoming active Elac UB5 has Class D in the bass and Class A in tweeter. Adam Audio also uses similar on the large SX models. You could always try one of those to see if you like the 'flavor' before committing to the complete re-architecture of your existing passive system... ;):p:cool:
 

CMB

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Just wanted some class d flavour in my bass :D and take the load off my Belles .. Might be totally pointless but thought I might give it a go, as long as the 'problems' we're not prohibitive .

Hello Thomas,

Pretty old thread now, I know, but may I ask the outcome of it?
Did you test passive bi-amping?
If yes, was it worth the set-up?

Thank you
Claude
 
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Thomas savage

Thomas savage

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Hello Thomas,

Pretty old thread now, I know, but may I ask the outcome of it?
Did you test passive bi-amping?
If yes, was it worth the set-up?

Thank you
Claude
Yea it was a waste of time and effort for me at least .
 

CMB

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:) Good to know - thank you
I hope it was worth the waste of time and effort to come to this conclusion :)
Thank you for having it done for me.
 

gene_stl

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Passive bi amping is fairly easy to build. My first bi amp was an RC network with a T pad on the output. The T pad is important to prevent the crossover frequencies from drifting as you adjust the shelving levels. You also could use an LC network which could have steeper slopes but might be a little more difficult to design and source components for.

Of course there are tons of active crossovers on fleabay. Most are professional and balanced but it would be hard to beat the parts expres DSP 408 to try and see if bi amping is for you. Bi amping is the most economical way to really ratchet up your sound quality. Power amps have gotten very inexpensive. Active crossovers too.
 

watchnerd

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Passive bi amping is fairly easy to build. My first bi amp was an RC network with a T pad on the output. The T pad is important to prevent the crossover frequencies from drifting as you adjust the shelving levels. You also could use an LC network which could have steeper slopes but might be a little more difficult to design and source components for.

I was thinking of ready-made speakers, not home built.
 

CMB

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Since you both are from the US..., I will hopefully receive this great American speakers next week to try.
USA - always worth a dream.

To name them: Klipsch Forte III.
They have these 4 speakers terminals.

I would like to test them at home with my tube amp (line magnetic 845 SET class A).
It will probably work out just fine like this.

However, I saw that the Forte Impedance drops a bit under 300Hz.
So in my unscientific mind, I thought I should try to bi-amp it, with a stronger amp for the bass.
Lucky me, I have a spare Yamaha DSP E800 wich I could try to make work.

Thomas had apparently tried something similar in 2017, but where not convinced.
I have a lot to catch up; Maybe I'll try it, as it doesn't cost anything.
 

watchnerd

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Since you both are from the US..., I will hopefully receive this great American speakers next week to try.
USA - always worth a dream.

To name them: Klipsch Forte III.
They have these 4 speakers terminals.

I would like to test them at home with my tube amp (line magnetic 845 SET class A).
It will probably work out just fine like this.

However, I saw that the Forte Impedance drops a bit under 300Hz.
So in my unscientific mind, I thought I should try to bi-amp it, with a stronger amp for the bass.
Lucky me, I have a spare Yamaha DSP E800 wich I could try to make work.

Thomas had apparently tried something similar in 2017, but where not convinced.
I have a lot to catch up; Maybe I'll try it, as it doesn't cost anything.

I'm skeptical of the "horns are best with tubes" idea.

High efficiency speakers may make tube hiss, noise, and microphonics more audible.
 
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CMB

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I'm skeptical of the "horns are best with tubes" idea.

High efficiency speakers may make tube hiss, noise, and microphonics more audible.

Thank you for your advice - You are absolutely right and actually I heard that at the store with an another tube amp. That is exactly why I would like to check them with my Amp before actually buying them.
 

Martin

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I passively biamplify my Von Schweikert VR-4 Gen III HSE using ICEpower class D on the bottom end and 300b based PSETs on the top end. I use Rothwell Audio inline attenuators to level match the amplifiers. I may be introducing harmonics into my top end with the tube amplifiers but I like the sound. In the end, that's what matters.

Martin
 

gene_stl

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Please say why it's an improvement.
Norman Crowhurst 's 1969 articles on the subject.
https://worldradiohistory.com/Archive-Radio-Electronics/60s/1969/Radio-Electronics-1969-03.pdf Page 32
https://worldradiohistory.com/Archive-Radio-Electronics/60s/1969/Radio-Electronics-1969-10.pdf page 42

https://www.audiocontrol.com/downloads/tech-papers/tech-paper-102.pdf
https://www.audiocontrol.com/downloads/tech-papers/tech-paper-104.pdf

https://www.semanticscholar.org/pap...f31cfcf971f3851851d801bc099be4274a30cf43?p2df

There are quite a few good reasons for converting your system to biamplification. Among some of the more common ones are:
• Additional peak output capability
• Increased damping factor at woofer
• Lower intermodulation distortion
• Improved safety factor for drivers
• Ability to use more exotic crossover networks
• Ability to optimize the crossover frequency
• Biamplified systems play louder, cleaner and more reliably.
Quoted and excerpted from Audio Control tech paper 104
 
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