Behringer A800 Stereo Amplifier Review

[Pulkass]

There are just so many stupid things in HiFi, the antagonism against active systems is just one of them. Active systems have been around in HiFi since the 1970s, but the cabal of manufacturers and dealers, and the magazines that supported them all held out, as with active there were fewer upgrading opportunities, no fancy 'speaker cables, no stupid passive biamping, and a higher entry level price, so there was no encouragement for ordinary enthusiasts to go active.

S.

WIFE ACCEPTANCE FACTOR- hahahahahahaha not in my case.....

 

[Pulkass]

There are just so many stupid things in HiFi, the antagonism against active systems is just one of them. Active systems have been around in HiFi since the 1970s, but the cabal of manufacturers and dealers, and the magazines that supported them all held out, as with active there were fewer upgrading opportunities, no fancy 'speaker cables, no stupid passive biamping, and a higher entry level price, so there was no encouragement for ordinary enthusiasts to go active.

S.

In fact, in my multi amped system, quality of cables just disappears, ......just average, decent cables, the most I own is a Flatline Nordost II, costing 200 euros in 2008, and Qed silver anniversary, the signal cable are all DIY, good metre cable, 8 euros per metre, or less.

 

[1roger]

There are just so many stupid things in HiFi, the antagonism against active systems is just one of them. Active systems have been around in HiFi since the 1970s, but the cabal of manufacturers and dealers, and the magazines that supported them all held out, as with active there were fewer upgrading opportunities, no fancy 'speaker cables, no stupid passive biamping, and a higher entry level price, so there was no encouragement for ordinary enthusiasts to go active.

S.

well, going active is a good idea if you really know what you are doing or...doesn`t mind the sound being all over the place as long as its tickle your pickle. for most people though its not going to be worth it to remove the original passive xovers ..many also forgets active filters bring a degradation of the signal on their own. I think its also not true to say passive bi amping is stupid. there are several clear advantages

 

[Pulkass]

Passive filters with all the coils do degrade signal a bit. My system was born without internal X overs.

 

[sergeauckland]

well, going active is a good idea if you really know what you are doing or...doesn`t mind the sound being all over the place as long as its tickle your picke. for most people though its not going to be worth it to remove the original passive xovers ..many also forgets active filters bring a degradation of the signal on their own. I think its also not true to say passive bi amping is stupid. there are several clear advantages

Active filters done in DSP have vanishingly small degradations, so I'm satisfied that there's no concern there. As to passive biamping, name one clear advantage that stands up to measurements. The only one I can think of is that the dealer sells a second totally unnecessary power amp.

S

 

[1roger]

As to passive biamping, name one clear advantage that stands up to measurements. The only one I can think of is that the dealer sells a second totally unnecessary power amp.

S

just off the top of my head, the work each amp have to do is simplified - there are no crosstalk(vertical) and each speaker have its own power supply. there is reduced back-emf meaning, the woofer doesn`t interact with the same amp as the tweeter and/or midrange(the inertial energy of the bass driver vs the mechanical damping of the cabinet/driver vs the electrical damping of the amp/crossover). the power overhead is increased somewhat, particularly for the midrange/tweeter. in a vertical setup.. the speaker cables can be very short. what can be measured here probably varies with components used.
my personal opinion is I don`t think one should go out and get a couple of expensive amps for passive bi-amping. but getting another amp 2nd hand for example, or two very affordable ones can make sense

 

[sergeauckland]

just off the top of my head, the work each amp have to do is simplified - there are no crosstalk(vertical) and each speaker have its own power supply. there is reduced back-emf meaning, the woofer doesn`t interact with the same amp as the tweeter and/or midrange(the inertial energy of the bass driver vs the mechanical damping of the cabinet/driver vs the electrical damping of the amp/crossover). the power overhead is increased somewhat, particularly for the midrange/tweeter. in a vertical setup.. the speaker cables can be very short. what can be measured here probably varies with components used.
my personal opinion is I don`t think one should go out and get a couple of expensive amps for passive bi-amping. but getting another amp 2nd hand for example, or two very affordable ones can make sense

I suggest you have a look at The Superposition Principle as to why what you mentioned doesn't matter.

Further to the Superposition Principle, as to power overhead, that doesn't change as each amplifier still has to supply the same number of volts to each loudspeaker, so there's no power saving, unlike with active biamping where there's a clear voltage reduction from each section over full-range amplification. This does of course require the amplifier to have decent power reserves, if it's so marginal that the tiny (relative) power taken by the tweeters affects the bass, then the solution is one better amplifier, not bi-amping.

Loudspeaker cables indeed can be very short, although I don't se how length matters, as it's loop resistance that matters, so if the cables are long, just make them thicker.

As to back-emf damping, that's not changed at all, as the woofer's back-emf still has to go through the passive crossover to get back to the amplifier's presumed very low output impedance. Again a benefit of active bi-amping over passive.

As I said before, I can't think of a single benefit of passive bi-amping except to the dealer who gets to sell another power amp and some more 'speaker cables, both unnecessary. Either stay single-amped passive or go fully active. Anything else is a total waste of time, effort and money.

S.

 

[1roger]

same number of volts yes... but with more current overhead. there are indeed more current available with two amps as oppose to one amp of the same model.
one also have to consider the power draw - a single speakers potential draw is less then two, which in itself increase the overhead..all other aspects staying the same. the goal is sq at reasonable levels though not db(of which overhead is relevant)

the point of back-emf relative to this particular subject ..is the bass and tweeter/mid have its own amp. meaning the emf from one driver to a lesser degree interacts with the other.

It have to be said, the potential benefits of passive bi-amping is probably greater with `cheap` equipment, due to compromises in the design and the internal electrical components used. its also true one could be better off with a single..more expensive and capable amp. it would be interesting if someone took upon themselves to do some competent measurements hinthint^^

 

[sergeauckland]

same number of volts yes... but with more current overhead. there are indeed more current available with two amps as oppose to one amp of the same model.
one also have to consider the power draw - a single speakers potential draw is less then two, which in itself increase the overhead..all other aspects staying the same. the goal is sq at reasonable levels though not db(of which overhead is relevant)

the point of back-emf relative to this particular subject ..is the bass and tweeter/mid have its own amp. meaning the emf from one driver to a lesser degree interacts with the other.

It have to be said, the potential benefits of passive bi-amping is probably greater with `cheap` equipment, due to compromises in the design and the internal electrical components used. its also true one could be better off with a single..more expensive amp. it would be interesting if someone took upon themselves to do some competent measurements hinthint^^

Starting at the beginning:-

Power draw:- Why should a couple of watts drawn by the tweeter affect in any way what the amplifier does, unless you're running the whole system at the limit, and/or the amplifiers are wholly inadequate for the task? All decent power amplifiers remain linear over their whole power envelope, so the Superposition Principle applies, and there's no issue with bass or treble power. It's only when an amplifier becomes non-linear that the Superposition Principle no longer applies, and one should never get to that state.

Back-emf is again a non-issue as one amplifier is just as capable of sinking the back emf, from different frequencies as two power amps. Again, the Superposition Principle applies here too.

It is always true that one will be better off with one decent power amp than two flawed amps. If the flawed amps are non-linear, then the Superposition Principle no longer applies.

Do you get the impression that there's something to this Superposition Principle?

S.

 

[1roger]

Would be nice to have this measured as I don`t particularly agree with you on this. "better off with one decent power amp than two flawed amps" aside ofc.. is it fair to dismiss these things on some theoretical principle?

"Why should a couple of watts drawn by the tweeter affect in any way what the amplifier does" the significant pulsating draw and disturbance of the bass will always affect the other drivers to a certain degree.

In any case from my own anecdotal experience.. with a fairly revealing speaker sporting an large ribbon tweeter(which is also power hungry and `high` current tolerant) ..the benefits of passive bi-amp is pretty apparant going back and forth

 

[sergeauckland]

Would be nice to have this measured as I don`t particularly agree with you on this. "better off with one decent power amp than two flawed amps" aside ofc.. is it fair to dismiss these things on some theoretical principle?

"Why should a couple of watts drawn by the tweeter affect in any way what the amplifier does" the significant pulsating draw and disturbance of the bass will always affect the other drivers to a certain degree.

In any case from my own anecdotal experience.. with a fairly revealing speaker sporting an large ribbon tweeter(which is also power hungry and `high` current tolerant) ..the benefits of passive bi-amp is pretty apparant going back and forth

Yes, unless you can find a flaw in the theory.

And that's the problem with passive bi-amping, pretty much all the evidence in favour is anecdotal. As far as I'm aware, there have been no rigorous trials done, but then why would there be unless flaws can be found in the theory that need examining?

S.

 

[1roger]

300 years worth of humbled people and their theory is why

 

[Pulkass]

I have envisaged multi amping since 1999. When l built my behemoths. Wife acceptance zero. Dealer's acceptance zero. Real hi fi buffs acceptance : 1000

 

[Gurkerl]

So how much of a bottleneck would this be in a typical stereo setup (with one or two subs)? I know the default recommendation is to go for the DIY Hypex or similar products, but this one can be had for 185€ at Thomann. You'd still need some sort of preamp/volume control with either, but the Behringer Combo would be around 300€ for lots of wattage. At roughly 100€ more, one could go for the lower end crown models. 360€ for the Crown XLS 1502 is getting close to Audiophonics MPA-S125NC territory, but that one has a lot less power, where I think it's safe to say it's better to safe up for a MPA-S250NC. Now we're at 470€ for the amp alone, without a way to control it. Choices, choices....
Any help on this topic is greatly appreciated!

 

[Pulkass]

While my multi inputs -ultimate tube -balanced pre amp, is being built, I m using a Topping L 30 pre amp, which is simply sensational, I bought it aftere reading the review on this very pages, amazing really.

 

[Nightyard]

I really like the a800 but there is some hiss coming from my speakers even with the a800 volume all the down and no inputs connected.

Is there anyway to remove this hiss? Power conditioner, rca shorting plugs,ferrite chokes, ac filter...something?

 

[Pulkass]

Right, then why does this thing have volume controls?

If one uses a control amplifier (preamp) with this thing, then what level are you supposed to leave this unit's volume controls at?

I had the exact same problem with my studio monitors. Eventually I set the volume control on my monitors to a level where I could get a decently usable range with the volume knob of my USB interface (essentially a control amplifier).

Not sure if that's the "optimal" way to go, though.

Arrived the second A 800, just now, connected to the 18'' sub woofer, Channel A-mono, ok, the SLAAAAAAM is the right one, finally the house is in shakeing position eheheheheh, only one problem, with no signal Channel B to zero of course, Channel A almost at the maximum, there s noise, it seems 220 V 50 hz noise, while the other A 800 being used for the main speakers has absolutely no such noise, the 2 pots full max.

 

[Nightyard]

Arrived the second A 800, just now, connected to the 18'' sub woofer, Channel A-mono, ok, the SLAAAAAAM is the right one, finally the house is in shakeing position eheheheheh, only one problem, with no signal Channel B to zero of course, Channel A almost at the maximum, there s noise, it seems 220 V 50 hz noise, while the other A 800 being used for the main speakers has absolutely no such noise, the 2 pots full max.

Is the a800 amp connected to the sub on the same socket/extension strip as other amp and preamp?

Have you flipped the switch into mono?

Are you using rca or xlr?

 

[1roger]

jut some suggestions.. have you tried swapping the signal cable from the amp with noise to the other and vice versa. if the cable is rca to xlr that could potentially be the issue as well..as the ground then floats. try connect the amp in regular stereo.
keep power cables and signal cables physically separated, and physically distance your gear from each other. all your gear should ideally be connected to the same power socket/strip like nightyard said and disconnect anything not related to what you need to power up your system. you can try switching off other equipment in your house hooked up to that particular socket line as well..but its probably not related to this as your other amp work fine. if nothing corrects the problem it could be a faulty component inside the amp.

 

[Pulkass]

I was just about to buy a A800 but read a comment on Thomann.de that the Amp give a "Pop" to the speakers, when turned on. Do you also hear this on your A800's?

No . I have two A 800