Axiom Home Page Forums General Discussion Technical Questions Bi-amplification?

My Yamaha RXv1800 supports bi-amping, which appears to mean connecting the "surround back" terminals on the AVR to a second set of front speaker terminals (removing the shorting bridges on those front speakers), and turning on the bi-amp feature in the AVR.

Is this worth doing with my M60s? If so, what's the advantage?

Thanks and regards,
David

Not really, no. You're still pulling off of one power supply in the Yamaha, losing your surround back/zone2 amps, and--since you're not changing the crossover in the M60--not seeing any actual theoretical benefit from bi-amping.

Ah. But the doco for the yammie says (wrt bi-amping): "Remove the shorting bars or bridges of your speakers to separate the low pass filter and high pass filter crossovers"

Whazzat mean?

Regards,
David

Not a whole lot. True bi-amping has the crossovers between the preamps and the amps.

David, this has been discussed at some length here several times. Although some manufacturers include a so-called "biamp" feature in their receivers, this is a misnomer, isn't true biamping and has no advantages. Biamping requires two separate amplifiers(as the term implies)and a separate external crossover before the amplifiers so that each amplifier gets only the appropriate frequency to amplify. The "feature" in question here simply feeds the same amount of maximum voltage that the receiver power supply section can deliver(and the same full frequency range)through two sets of output transistors(one previously unused for back surround speakers)rather than one; maximum power available isn't doubled, as is sometimes claimed, or increased by any amount.

Sorry for the duplication, John: I searched on bi-amp (0 results), bi-amplification (too many to count), but didn't think of biamp.

Anyway, thanks for the info.

Regards,
David

No criticism was meant, David; searching can be difficult(impossible?)at times. Another comment that can be added is that, contrary to the statement quoted from the manual, removing the connecting bars doesn't make the high and low sections of the crossover separate; they already are separate and have to be to send the high and low frequency drivers the right frequencies in normal operation. The reason for removing the connectors is that the power doesn't know that it's supposed to go only into the speaker, and if the connector was still there when "biamping" it would also go through the connector, up the other speaker wire and into the opposite channel, probably damaging the output transistors there.

The 'new' search engine that came with the site changes really doesn't work.
The old search engine was far more effective.
Mind you, even the Google version that Peter posted some time back i don't find very effective. I had more luck manually scrolling through my own posts, using a relative time frame of mind and recall of subject headers to find posts that clearly still exist, but that the search engines cannot find.

Maybe they have not been allowed to access the archived text.

I'm glad to see I'm not he only one that thinks the search function is below par.

There's a search function?

j/k...

Funy thing is that it usually works for me. I thought it was the same as the old one.

I tried some simple searches for old topics that had rare words in them, not used often like some obscure speaker brand name and i found nothing.
Yet if i go back to my very first fifty or so posts where i knew i had discussed the topic, i find it manually.

Even the Google search didn't find it so i lost all confidence in using the search function since the forums were updated.

Part of the problem is your only allowed to search within a 1 year gap now, so you have to adjust both time fields. For ex., older than 2 years and earlier than 3 years, pain in the you know what.....

I can still find a great post by searching for the keyword "torch", putting my name in the display name box, and searching posts older than 5 years and newer than 4.

When I think about you I torch myself.

That sounds wonderfully painful.

My M80's are bi-amped. And I like it that way.

I had the extra channels on my amp and was using Canare 4S11 quad-cable anyway, so one afternoon (many months ago) I decided to bi-amp one channel to see if I could possibly tell a difference. Just split the RCA-outs from my AVR and fed them into 2 pairs of channels on my amp. Definitely didn't use any sort of external crossover.

Well, after a few CD's worth of L/R balance listening, I was actually preferring the bi-amped channel. I swapped the channels to make sure it wasn't the speaker, and still preferred the bi-amped channel. Believing full-well that it was just my imagination, I asked my wife for help and told her that I had re-wired one speaker, and asked which one she liked better. She too, picked out the bi-amped one. We both though the bi-amped channel was a bit 'fuller' on the bottom end. The bass was just a bit better and the sound was just, well, a tiny bit more pleasant. It was subtle, definitely, and not really apparent on every recording. We just preferred it.

So from that, I bi-amped both and my system has stayed that way ever since.

If it was a completely useless feature, then why would axiom include in on their speakers?

Marketing.

What is being discussed above is not bi-amping. This article explains it in laymens terms.

http://www.gcaudio.com/resources/howtos/biamping.html

Utility is one thing; customer demand is another. Sometimes they coincide, sometimes they don't.

good point.

It's a fact that your M60's support it. So if your receiver supports it amd you've got the extra channels and the speaker wire lying around, why not try it? It won't cost you anything, and you're certainly not going to cause any harm to the system.

Maybe it'll sound better. Maybe it'll sound exactly the same. Maybe it'll sound worse.

Whatever the outcome is, you can easily decide for yourself.

As I said, I believe that my M80's sound a tiny bit better when (pseudo) bi-amped. That's all it took for me. Is it in my head? Maybe, maybe not. But that's all that the enjoyment of music is anyway.

I have to agree with Peter, try it and decide for your self if you like what you hear.

But do keep in mind that your mind can create its own reality.

I love bring back threads from the dead

The search feature isn't great, true. I think the worst part is that it doesn't let you search past a year; Lots of info not searchable that needs to be asked again.

Back to biamping. Since I have two extra channels on the MPS-2, I'll biamp my M60's with Canare 4S11 wire. I don't have an external crossover but I'll give it a shot anyway since I have two Amp modules sitting idle. At least they are separate amps with independent power supplies.

Try it both ways and let us know your thoughts.

Mistico, don't waste your time. I had the MPS-1,as most know, that kept shutting down at louder levels. Lonnie at Emotiva said to try bi-amping by removing the clip on my speaker terminals and use one amp for the woofers, and the other for the upper drivers.

I told him that others say this is not 'true' bi-amping because of the crossover in the speakers. He said everyone at Axiom telling me that was nuts.

I will say that there was absolutely "no" difference. Any gain, was so minimal a person could not audibly notice.

Actually, you are all wrong. Bi-amping (two amps together) originated shortly, after the advent of 4 ohm speakers.
This allowed owner's of 4 ohm speakers to continiously enjoy their music, using the second amp..........after the first amp would shut down.

I have a few questions that will answer certain things for me.

The M60/M80's have posts for biamping. After reading, now understand the differences between passive-biamping and active-biamping(true biamping)
My questions are:

1. Do the M60/M80's have a crossover for the lower frequencies/bottom half and one for upper frequencies, 2 crossovers total?

2. If they have 2 crossovers, is the bottom one connected only to lower binding posts and the top one to the top binding posts, or do both sets of binding posts go to the same crossover?

If each set of binding posts go to separate crossovers, I'll do passive biamping to try out at least. If they both go to the same crossover, then I won't bother.

Thanks for all the info on this.

I would not bother.

if the x-over is getting enough power to run the speaker. It will not mind, only if it is too much or not enough power.

I don't quite get the 'don't bother' posts. It's not like it takes hours of work to do a little test run of "biamping" one's speakers. Like I said, if you've got the extra cables lying around (who doesn't?), the extra channels, and bi-ampable speakers, why not try it? This isn't like getting a tattoo or joining a cult (some might disagree ). I consider 'tinkering' to be part of the great hobby of home audio. Perhaps others do not, and that's totally cool.

<Forest Gump> Like my momma always used to say about tryin' new foods, "you won't know you don't like it until you try it". </Forest Gump>

It's also easy enough to bi-amp just one speaker. Then you can fiddle with the balance to see if you could tell a difference, L to R.

Good luck, have fun, and do try it out. Let us know how it goes.

Peter, this is not biamping, so there is no benefit and your not increasing the power by doing it this way. That is why I say don't bother. If you want to give it a shot by all means, go for it, I did once.

This is, in fact, bi-amping. It's not active bi-amping, but it's definitely passive bi-amping. I too doubt that there's any benefit, but...

true, I should have said it physically is bi-amping. (passive) that is...

Riiiiggghhhhhttt. Once. Your secret is safe with us.

It's clear that even in passive biamping the speaker has more wattage available. Now I need to actually do it and see/hear if it makes a difference. I'm just not sure if I want to play them that loud. They already get 200W each so I'll do this when I'm bored one day since I have the cables and connectors.

For now I'm happy just listening and not tinkering heehee

Actually, that is incorrect. We've been down this road a million times, so a quick search should provide all the info you need. But the bottom line is no, you do not get more wattage.

Of course, it does not hurt to try. In fact, what fun would it be if we couldn't tinker?

To save some time, i think his point is that the amp will only provide the maximum current available, no matter how many paths you provide for that power. Unless you have independent power supplies passive bi-amping is really just bi-wiring. For example, I bi-amp in my car, where the cross-over gets a signal for the tweeter from a good moderate power amp, and the mid-bass gets a signal from a more powerful amp. That is true bi-amping (as I understand it).

To be clear, I'm not implying you didn't' know this, just figured many readers are on different places on the learning curve. (Be damn funny if my example was wrong!)

If your crossover is external (ie, before the amps in the signal path), then you're actively biamping. If your crossovers are internal to the speaker, but the speaker has separate binding posts and you're using 2 separate amps (possibly with separate power supplies?) then you're passively biamping. If you're using 2 runs of wire to 4 separate binding posts, back to 2 binding posts on the amp, you're biwiring.

This oldie-but-goodie has some discussion on the subject.

mistico, your incorrect, your not getting more power.

Damn, Ken.

You sure know a lot about this "bi" stuff.

ha ha, good one Mark for that CA boy.

I have searched plenty and my conclusion is that if you have a receiver or an amp with a single power supply there will be no difference. I have 7 INDIVIDUAL amps though, each with their OWN power supply and completely independent circuitry except for the wall outlet.

See my above reply.

I'm very clear on the differences between active bi-amping, passive bi-amping and bi-wiring.
My argument is that if you have individual amplifiers each with separate power supplies and you assign two amps to each speaker, you are in fact delivering more wattage.
I'm not referring to configuring your receiver to bi-amp or using two channels from a 5-7 channel amp for a single speaker. I'm talking about assigning two SEPARATE amps to each speaker.
Can someone explain how this would not provide more wattage? I've searched and nothing indicates this.
I'm clear that true bi-amping requires the disabling of the internal crossover in the speakers and adding an external crossover, but passive bi-amping with two individual amps should still provide more power.

You are in fact NOT delivering more wattage to the speaker, unless you get rid of the internal passive crossovers in the speaker and use an external setup, as we have mentioned.

300 watts to the woofers, and 300 watts to the tweeter/mid section is not giving you 600 watts.

I'm not saying it would deliver twice as much, but if one amp delivers 200watts and and I connect one to the mids/highs and one to the lows, even if some wattage is lost in form of heat(crossover frequency filtering), I would still get more than 200watts to that speaker, even if only 220watts total. No?

Theoretical peak, yes, but since you're unlikely to be getting close to theoretical peak, then probably not. Then again, more headroom is more headroom...

I know many report hearing better low end from passive bi-amping and, as you have indicated, you now have an amp that is not losing any power to produce the top end of the spectrum it is able to push a little more for the low end requirements of the speaker. Is it a night and day thing? I haven't read anywhere that it is and in my own brief experience the benefit wasn't worth the effort but I didn't have an amp set up like you are proposing. Give it a try

No, mistico; the 200 watt amplifiers are still just 200 watt amplifiers. Using them with the same internal crossover in the speaker can't somehow increase their power capability; each section of the speaker can get 200 watts, as was the case before.

That's what you gain: headroom. You are making sure your hi-mid and mid-bass each get all off 200 watts they want. With only one amp you have 200 to spread across all speakers, but it is not 400 watts and neither set of speakers has access to 400 watts of power. they each still only have access to 200. Your set up helps when ch 1 (mid-hi, etc) sucks so much of the power tha ch 2 (mid-bass) would otherwise be limited to less than 200 in that instant.

I still don't get this internal/external crossover issue. How does that matter in this discussion? in the set up I describe above, one amp has a direct line to the mid-bass and one separate has a direct line to the tweeter. Why does it matter where the crossover lives?

OK, well, here's the deal: tweeters almost never need 200 watts, or whatever. So you're really gaining almost nothing with passive biamping. Ooh, 2 more watts, or whatever at millisecond peaks.

Active biamping, where the crossover is external, ie, before the amps, lets you use appropriate amps to the drivers. The link to the active/passive article in the article I linked talks about this.

I see and understand what you're saying and I appreciate you explaning this more than once.

So why is it not sinking in then.

Oh, it sunk in...after reading it a few times hehehe.

But each section would receive 200watts vs 200watts for both sections. Here we go again...

It's been a good discusion and much has been learned.

I think it comes down to how good your amp actually is, I am certain I would not hear any difference passive biamping the M80's with the A1400, but with my 3808 I could hear a slightly better lower end, but I didn't feel it was worth the extra effort and money to keep it set up that way, as my PB13 is usually on and takes care of the low end much better than the 3808 and M80's do when biamped.

Its all good...

I just had to put my 2cents in on this. I seen a Linn dealer back in Dec. anyway Linn came up with Aktiv crossover and Aktiv cards it is an external crossover. The cards go into the amps so you can put say 4-channels on one speaker, as he said to fine tune the speaker, I thought spl meter, oh well what a great marketing idea. Oh and it only works on there speakers.