Advice/Tips for bi-amping

[Robh3606]

Hello

Did I get this right that the crossover is split into 2 halves with separate terminals and the passive crossover still provides the crossover for the speaker??

If that's true you are doing a passive bi-amp. Each amp is getting a full range signal. If that's the case I don't see any advantages over a single amp. If you had an active crossover it makes more sense and you would be bi-amping the system.

Rob

 

[Robh3606]

Single-amping and single-wiring is musically superior to bi-amping/bi-wiring.
It is always better to do single-amping with one superior amp than bi-amping with two inferior amps.
So I recommend not to buy a second amp for bi-amping but to upgrade to one superior amp and do single-amping.
Please try it and you will agree.

Matt

Not in my experience especially using an active crossover which is a true bi-amp configuration and not a passive bi-amp.

Rob

 

[Lagonda]

Not in my experience especially using an active crossover which is a true bi-amp configuration and not a passive bi-amp.

Rob

Bi-amping does not require a active crossover to be "true" !

 

[Robh3606]

Bi-amping does not require a active crossover to be "true" !

Yes it does if you want the advantages of feeding a limited bandwidth to the amps used. Passive bi-amp is nonsense and buzz words. Feeding full-range signals to both amps completely defeats one of the primary reason and advantages of bi-amping.

For example if you use a passive bi-amp and use a fullrange signal into the treble amp you loose the extra headroom gained by using limited bandwidth signal and if you have bass transients and clip the amp guess where it goes??

This will not happen with an active crossover and allows for a lowered powered amp up top to used if desired. You also get more headroom by bandwidth limiting the amps.

Rob

 

[Lagonda]

Yes it does if you want the advantages of feeding a limited bandwidth to the amps used. Passive bi-amp is nonsense and buzz words. Feeding full-range signals to both amps completely defeats one of the primary reason and advantages of bi-amping.

For example if you use a passive bi-amp and use a fullrange signal into the treble amp you loose the extra headroom gained by using limited bandwidth signal and if you have bass transients and clip the amp guess where it goes??

This will not happen with an active crossover and allows for a lowered powered amp up top to used if desired. You also get more headroom by bandwidth limiting the amps.

Rob

You also get more headroom by feeding separate parts of the crossover with each their own power amplifier, calling bi-amping "true" because there is a active filter involved is "un- true" The amplifier driving only the treble load will have a easier job than an amplifier driving the full load. MBL's sound much better bi-amped, even when using only the passive crossovers, the deep-bass section is swallowing most of the available power.

 

[Robh3606]

You also get more headroom by feeding separate parts of the crossover with each their own power amplifier, calling bi-amping "true" because there is a active filter involved is "un- true" The amplifier driving only the treble load will have a easier job than an amplifier driving the full load. MBL's sound much better bi-amped, even when using only the passive crossovers, the deep-bass section is swallowing most of the available power.

Current not voltage, the voltage headroom is not effected and remains the same. I understand what you are saying but they are clearly not the same and the active crossover version is better overall and what is traditionally considered what bi-amping is. We agree to disagree on this one

Rob

This sums up the differences better than I can.

Active crossover:

1.16 - Adding up the Plusses

• Effectively (up to) twice the 'real' power of the amplifiers themselves
• Reduced intermodulation distortion
• Elimination of the low frequency passive crossover, its inherent losses, potentially poor linearity and crossover point inaccuracy
• Reduction of the difficulty of the load presented to the power amplifier
• No padding is required to align the driver sensitivities, so we are not simply wasting power
• The damping factor is greatly improved for both the low and midrange loudspeakers
• Complete freedom from any interaction between the loudspeaker driver (and its environment) and the crossover network
• Cost savings, since complex passive crossover networks are not needed
• Bi-wiring is included free!
• The flexibility to choose amplifiers which are at their best within a defined frequency range
• Ability to match amplifier power to the exact requirements of the drivers for maximum overall efficiency

I could go on (and on) here, but I shall resist the temptation. There is (IMO) no reason to not use biamping wherever possible, from small (i.e. computer) speakers through to top of the line hi-fi. The benefits far outweigh the disadvantages in all cases.




5.0 - Passive Biamping (aka Active Biwiring)
Although this is a topic I've mentioned briefly, it needs to be discussed properly. Using two amplifiers and two sets of speaker cables to drive the existing passive crossover is something I call 'passive biamping' or 'active biwiring'. Various websites may claim that it's true biamping, but it's not, never was and never will be.

In some cases users may hear an improvement, but make sure that it really is an improvement and not just a difference. Because you have separate amps driving the two sections of the crossover, you can easily have a level mismatch that leads you to think that the sound is 'better'. The gains of the two amps used must be identical, or the original balance between mid and high will be changed. Naturally the specific frequency depends on where the passive crossover splits the signal. Apart from (usually) a slightly easier load on the amps, both amplifiers still reproduce the full audio bandwidth, so there is no effective power gain.

In general, it is likely that the improvement - assuming there is an actual improvement of course - will be small. It will commonly be so small that the additional cost cannot be justified, but this is cold comfort if you've already bought the amplifiers and speaker cables. Speaking of which, make sure that you read the articles on this site about 'high end' (rip-off IMO) speaker cables before parting with large sums of money.

For some additional details on the real differences between active an passive systems, see Active Vs. Passive Crossovers. In particular, loudspeaker damping is always affected (sometimes seriously) by any passive filter, and commonly right at those frequencies where good damping may help control cone breakup and other unwanted effects.

BiAmp (Bi-Amplification - Not Quite Magic, But Close) - Part 1

ESP - The Audio Pages. How to biamp or triamp your hi-hi speaker system for greatly improved sound, and higher sound levels with less distortion.

sound-au.com

 

[Lagonda]

Current not voltage, the voltage headroom is not effected and remains the same. I understand what you are saying but they are clearly not the same and the active crossover version is better overall and what is traditionally considered what bi-amping is. We agree to disagree on this one

Rob

This sums up the differences better than I can.

Active crossover:

1.16 - Adding up the Plusses

• Effectively (up to) twice the 'real' power of the amplifiers themselves
• Reduced intermodulation distortion
• Elimination of the low frequency passive crossover, its inherent losses, potentially poor linearity and crossover point inaccuracy
• Reduction of the difficulty of the load presented to the power amplifier
• No padding is required to align the driver sensitivities, so we are not simply wasting power
• The damping factor is greatly improved for both the low and midrange loudspeakers
• Complete freedom from any interaction between the loudspeaker driver (and its environment) and the crossover network
• Cost savings, since complex passive crossover networks are not needed
• Bi-wiring is included free!
• The flexibility to choose amplifiers which are at their best within a defined frequency range
• Ability to match amplifier power to the exact requirements of the drivers for maximum overall efficiency

I could go on (and on) here, but I shall resist the temptation. There is (IMO) no reason to not use biamping wherever possible, from small (i.e. computer) speakers through to top of the line hi-fi. The benefits far outweigh the disadvantages in all cases.




5.0 - Passive Biamping (aka Active Biwiring)
Although this is a topic I've mentioned briefly, it needs to be discussed properly. Using two amplifiers and two sets of speaker cables to drive the existing passive crossover is something I call 'passive biamping' or 'active biwiring'. Various websites may claim that it's true biamping, but it's not, never was and never will be.

In some cases users may hear an improvement, but make sure that it really is an improvement and not just a difference. Because you have separate amps driving the two sections of the crossover, you can easily have a level mismatch that leads you to think that the sound is 'better'. The gains of the two amps used must be identical, or the original balance between mid and high will be changed. Naturally the specific frequency depends on where the passive crossover splits the signal. Apart from (usually) a slightly easier load on the amps, both amplifiers still reproduce the full audio bandwidth, so there is no effective power gain.

In general, it is likely that the improvement - assuming there is an actual improvement of course - will be small. It will commonly be so small that the additional cost cannot be justified, but this is cold comfort if you've already bought the amplifiers and speaker cables. Speaking of which, make sure that you read the articles on this site about 'high end' (rip-off IMO) speaker cables before parting with large sums of money.

For some additional details on the real differences between active an passive systems, see Active Vs. Passive Crossovers. In particular, loudspeaker damping is always affected (sometimes seriously) by any passive filter, and commonly right at those frequencies where good damping may help control cone breakup and other unwanted effects.

BiAmp (Bi-Amplification - Not Quite Magic, But Close) - Part 1

ESP - The Audio Pages. How to biamp or triamp your hi-hi speaker system for greatly improved sound, and higher sound levels with less distortion.

sound-au.com

Yes some guy making claims is truly the final word ! And lets ignore the fact that most active crossovers are not transparent.

 

[Robh3606]

Yes some guy making claims is truly the final word ! And lets ignore the fact that most active crossovers are not transparent.

Well no one has the final word, I posted that because it was a good summary did you read the entire piece and part 2 as well or did you just blow it off???

No electronic gear is completely transparent, as always name your poison. If you choose wisely just like any other gear it won't audibly detract from what you already have. I have 3 different analog actives and they all fit the bill.

Not transparent is a poor excuse for not using an active crossover.

Rob

 

[Lagonda]

Well no one has the final word, I posted that because it was a good summary did you read the entire piece and part 2 as well or did you just blow it off???

No electronic gear is completely transparent, as always name your poison. If you choose wisely just like any other gear it won't audibly detract from what you already have. I have 3 different analog actives and they all fit the bill.

Not transparent is a poor excuse for not using an active crossover.

Rob

I did read the whole thing, seems like a write up done by someone selling their own way to the holy grail. The best results i have achieved is with active crossover on the sub bass section only, letting a passive do the higher frequencies, it seems to be the way most larger speaker systems do it too. Gryphon, Rockport Wilson, MBL and Martin Logan, maybe with good reason ! I have never heard a active speaker i found satisfying, i have owned both Dynaudio and B&O that would qualify in that category.

 

[Robh3606]

I did read the whole thing, seems like a write up done by someone selling their own way to the holy grail. The best results i have achieved is with active crossover on the sub bass section only, letting a passive do the higher frequencies, it seems to be the way most larger speaker systems do it to. Gryphon, Rockport Wilson, MBL and Martin Logan, maybe with good reason ! I have never heard a active speaker i found satisfying, i have own both Dynaudio and B&O that would qualify in that category.

Your right about how it reads. I also do active sub bass crossovers as well with some of my set-ups. And my favorites are also passive speaker designs. I think we have more in common than we realize. Thanks for taking the time on the read.

All the bi-amp systems I have or have had were always a mix analog active just providing the slopes with any HF driver EQ done with passive components of in a 3 or 4 way the rest kept in place so no woofer passive and mid-range first poles only. The balance all passive.

The only experience I have with a "modern" active system DSP/Amp in box is an inexpensive pair of active near fields I used as computer speakers. Impressive for what they are but limited SPL and resolution and also needed a subwoofer. So I don't have your experience WRT SOTA DSP based systems.

I have an all analog active 4 way L,R system in my HT that does dual work as a stereo set-up and it's fun and dynamic as hell. As much as I like my passives they simply cannot keep up as far as dynamics and SPL. Much higher over all sensitivity @ 98 dB meter. I guess everything has its trade offs.

Rob

 

[Alpha121]

I recommend buying 2 superior amps, it will outperform one superior amp every time ! Use the same amps/signal and speaker cable for all outputs !

I totally agree with this.
Biamping has to be done properly, but if so renders superior results. It's not a question of two inferior amps, who would do that anyway?

I am biamping my Focal Scala Utopia Evo with Pass Labs XA160.8 on the mid/highs and X600.8 on the bass to very, very good effect. I have tried both amps as single drivers, and the biamped configuration is far better than either amp on its own in mono mode.

The amps have to match for best results however. I think the Pass line is uniquely suited for this.