BiAmp Experience

[leonski]

This thread is for those of you who either DO biamp in some fashion, and we'll use the most open definition OR would, at some point LOVE to join that club.  

Any experience or input or even QUESTIONS are fair game.     If, as likely, I don't know the answer, somebody will be along shortly with some insight or maybe a link.

I love the idea of active biamp using a crossover between PREAMP and Main AMP.  You can use less powerful amps and Still end up with rockin' high levels and clarity.  
But these days, I continue to use the crossover IN the speaker, by removing the jumpers Magnepan fit the speaker with.   As a side-note, the LATEST Maggies in the 
'point 7' series NO LONGER support biamp OR bi-wiring.  Those owners wanting to biamp need to perform surgery and go into some newish territory.

Have fun:

[repeetavx]

More and more speaker manufacturers are getting away from the biwiring/biamping connections. I personally like it, but the speaker manufacturers seem to think that the way they're engineering it (their crossovers) that a single power source is the best way to go.

Most of us (in this thread) would disagree.

[garbulky]

Of interest the airmotivs appear to be active bi-amp speakers.

[wizardofoz]

For proper Bi-Amping (well in the case of the LX521 its Quad) check out www.linkwitzlab.com - these are DIY options but easy to build kits are also available - a bit over and above IKEA for the woodwork but doable for most I would think, and the electronics now all off the shelf MiniDSP solutions. I use mine with 2 x XPA-5G2 amps - one per speaker with 4 channels driven.

[leonski]

I've tried wading thru the MiniDSP stuff and can't make head or tails of it. Just what IS it and can I actually use it for a 2-way crossover? Can I locate them at each amp? Cost?

And yes, the Airmotiv is biamp. So are a version of the Paradigm Atom, the AudioEngine A5 and MOST pro monitors. My brother was looking at some JBL 3-ways with 3 amps per speaker. He is a JBL guy. They are rated to something like 130db! What the heck, I asked are you going to DO with ANY speaker at 130 db? And how do they SOUND at a more normal level inside your house?
Now, his ancient 4311s were nice and a good expression of old-school 12" 3-way ported speakers of medium to high sensitivity. I liked 'em enough to buy some SoCal made copies from RSL.

[linvincible]

For the record then, in case someone has specific questions or wants to see who did how

I have the same kind of setup as Leonski and can confirm I heard a difference compared to just having monoblocks.

But, I still use the crossover in the speakers

Reasons:
- I'm not brave enough to perform surgery in my speakers and bypass the filter
- It would require a proper two way configurable filter, that has a cost
- I don't have any more room in my rack

Maybe in the future (or if I find a used Pass Labs filter!) I'll go through this for I believe it will take my system to a whole new level again!
For the moment I use split XLR cables from the XSP-1 to my 4 XPA-1s

[djoel]

I made sure David F from Ascend Acoustics make my Sierra Towers for true Bi-amping, appropriately design X-over and all for when I was ready I could take advantage of some great Class A amps, and this thread would be an perfect way to make the change.

Thanks

Dan

[leonski]

When I was thinking about starting down the biamp trail, I wondered about using 4 of the 5 channels of an XPA-5 and having either a non-powered sub for the 5th channel OR simply a 'spare' channel.
Any thoughts?
DJoel, with your XPA-5, YOU could do that without buying more amplification.

[garbulky]

Jan 15, 2015 8:33:29 GMT -5 djoel said:

I made sure David F from Ascend Acoustics make my Sierra Towers for true Bi-amping, appropriately design X-over and all for when I was ready I could take advantage of some great Class A amps, and this thread would be an perfect way to make the change.

Thanks

Dan

How did he do that if you don't mind me asking? You're talking about active bi amping right?

[djoel]

Jan 15, 2015 15:23:32 GMT -5 garbulky said:

Jan 15, 2015 8:33:29 GMT -5 djoel said:

I made sure David F from Ascend Acoustics make my Sierra Towers for true Bi-amping, appropriately design X-over and all for when I was ready I could take advantage of some great Class A amps, and this thread would be an perfect way to make the change.

Thanks

Dan

How did he do that if you don't mind me asking? You're talking about active bi amping right?

Not sure if they're actually active in the sense, but they're not like 98% of the speakers out there where the cross over is wired directly to both high/ mids and bass.

DJoel

[djoel]

Jan 15, 2015 14:46:07 GMT -5 leonski said:

When I was thinking about starting down the biamp trail, I wondered about using 4 of the 5 channels of an XPA-5 and having either a non-powered sub for the 5th channel OR simply a 'spare' channel.
Any thoughts?
DJoel, with your XPA-5, YOU could do that without buying more amplification.

Hmm, I guess I can try that for now or until I go surround, I think I need speaker cables thou?

Djoel

[Gary Cook]

Jan 14, 2015 21:15:34 GMT -5 repeetavx said:

More and more speaker manufacturers are getting away from the biwiring/biamping connections. I personally like it, but the speaker manufacturers seem to think that the way they're engineering it (their crossovers) that a single power source is the best way to go.
Most of us (in this thread) would disagree.

Not me, I agree with the speaker manufacturers. Especially with the ready availability of hugely powerful amplifiers at reasonable prices, well reasonable compared to past prices. Seriously does anybody really think that they need more power than the 1KW that an XPR-1 can deliver into an 8 ohm home stereo set up? Not me that's for sure, the relatively puny 275 WPC from an XPA-5 is way more grunt than I ever use for 2.1 stereo listening.

We are also well past the time when passive cross overs used to be lossy, inaccurate and inconsistent. Or when those that weren't lossy, inaccurate and inconsistent were grossly expensive. High quality componentry these days is only mildly more costly than the average.

I've tried bi amping many times over the years, even tri amping once. With Class A, Class AB and Class D amps and all combinations of them. I haven't found it to be remotely close to being worth the time, money and effort required. There are simply more benefits to be gained from other items in the set up.


Cheers
Gary

[leonski]

Yes, you'll need MORE speaker cable!
And, if you have JUMPERS between sets of binding posts, they've gotta GO, too.
My Maggies have 3 PAIR of banana plugs. 2 pair are JUMPERED from the factory. The jumpers get removed before either biwiring OR biamping.
In order to go 'true' biamp, which apparently means WITHOUT speaker level crossover, I must pull up the sock and do some surgery. The problem with Maggies is that for some crazy reason, the sock is held on the bottom of the panel with
about 200 STAPLES, each of which must be removed.

And as a general TEST, try NOT to run your amp THRU the Panamax. It may limit the amp in some fashion and if audible, it won't be good. If possible, try it both ways! I see the XPA-5 is 1800 watts MAX which is redline for a 15amp circuit. I'd want the amp and sub
on their OWN breaker.

[stlaudiofan1]

Jan 15, 2015 17:12:32 GMT -5 Gary Cook said:

Jan 14, 2015 21:15:34 GMT -5 repeetavx said:

More and more speaker manufacturers are getting away from the biwiring/biamping connections. I personally like it, but the speaker manufacturers seem to think that the way they're engineering it (their crossovers) that a single power source is the best way to go.
Most of us (in this thread) would disagree.

Not me, I agree with the speaker manufacturers. Especially with the ready availability of hugely powerful amplifiers at reasonable prices, well reasonable compared to past prices. Seriously does anybody really think that they need more power than the 1KW that an XPR-1 can deliver into an 8 ohm home stereo set up? Not me that's for sure, the relatively puny 275 WPC from an XPA-5 is way more grunt than I ever use for 2.1 stereo listening.

We are also well past the time when passive cross overs used to be lossy, inaccurate and inconsistent. Or when those that weren't lossy, inaccurate and inconsistent were grossly expensive. High quality componentry these days is only mildly more costly than the average.

I've tried bi amping many times over the years, even tri amping once. With Class A, Class AB and Class D amps and all combinations of them. I haven't found it to be remotely close to being worth the time, money and effort required. There are simply more benefits to be gained from other items in the set up.


Cheers
Gary

I was of the same opinion, until I bi-amped my Magnepans with the 4 1Ls.  It is the beast sounding amp option I have had in my system.   I had a Parasound A21 for a year. Lots of power, but I did not find it musical.  I did have a Threshold T-200 amp at one time as well.  It sounded much in the same vain as the 4 1Ls in class A, but not as refined.  Lots of folks like that in your face punch and detail.  I'm in the effortless silky smooth flowing sound camp.  Also, if the rest of your system isn't up to snuff, that class A  smoothness can sound dullish.

[leonski]

I use a PAIR of the A23s, the '21s little brother, with ONE sitting behind each of my Maggies. I had briefly considered the quad of 1Ls, but realized the ADDITIONAL expense of yet another dedicated line would add another 500$ MINIMUM to the project.
Don't forget the the Halo amps are ALSO 'rich bias' and especially the '21 have the first 10 or so a side in 'a'. The '23? Not so much, but I'm going to recover MOST of the difference when going to a line level crossover and DITCHING the one in the speaker.

[orthikon]

I have 3.6R and thinking of using the XSP-1 to biamp. Is this possible using the bass management option?

Thinking of using 4x XPA-1s as I already have two or 4x XPA-1Ls if I can find a deal on them.

The stock 3.6R passive crossover settings are 200 HP 6db and 250 LP 18 db. know the XSP only does 12db so that issue aside is this doable?

If not, what active crossover are you guys using?

[KeithL]

The MiniDSP is a digital signal processing computer with inputs and outputs.

There are several models, each of which has different specific capabilities, but basically they're giving you a little computer in a box. Each includes some number of digital or analog inputs and outputs (the ones with analog inputs and outputs have the required A/D or D/A to convert the signal at the analog connector into the digital signal required to get it to or from the computer). You can then buy software modules which you can install on the computer that DO things. So, to make a simple two-way crossover, you would buy the one with two analog inputs and four analog outputs; you would then add the software module that gives you two high-pass filters and two low-pass filters, load that software into the box, set it to do what you want, and you would then have an active crossover. (Of course you can configure the settings used by the software module so the filters are at the right frequencies, and pick what type of filter you want.)

Basically there are two ways of making an analog line level active crossover.

1) You can build the circuitry out of linear analog filter circuits. This works well as long as you know what you want in advance - since changing things like the crossover point generally requires you to change at least a few parts. Even though you can build specific circuits that let you use some sort of control to change the settings, you'd end up with a lot of knobs and controls, and the circuitry becomes very complicated, and you still can't easily switch between different filter slopes and such. It's also very complicated to build very sharp filters. (A 12 dB/octave filter is pretty simple; a 36 dB/octave filter takes three times as many parts, and the math needed to calculate what they should be is a lot more complicated.)

2) You can convert the analog input signal into digital; feed it into a computer (a DSP); let the computer do all the filters *as math*; then convert the results back into analog audio signals to send to the output. This is the method commonly used when complicated processing is required.

The MiniDSP is a sort of erector set for doing 2) ... they provide the computer, the I/O, and a bunch of programs you can load into that computer to make the box work as a crossover, or an EQ filter, or even to run Dirac in one version. I've never worked with one, but supposedly they've made the process of configuring and loading the programs simple enough that pretty well anybody can do it.

The reason it seems so complicated is that the little box can do a lot of different things (but the benefit is that you get to pick exactly what).

Jan 15, 2015 2:57:17 GMT -5 leonski said:

I've tried wading thru the MiniDSP stuff and can't make head or tails of it. Just what IS it and can I actually use it for a 2-way crossover? Can I locate them at each amp? Cost?

And yes, the Airmotiv is biamp. So are a version of the Paradigm Atom, the AudioEngine A5 and MOST pro monitors. My brother was looking at some JBL 3-ways with 3 amps per speaker. He is a JBL guy. They are rated to something like 130db! What the heck, I asked are you going to DO with ANY speaker at 130 db? And how do they SOUND at a more normal level inside your house?
Now, his ancient 4311s were nice and a good expression of old-school 12" 3-way ported speakers of medium to high sensitivity. I liked 'em enough to buy some SoCal made copies from RSL.

[KeithL]

Yes - and no.

Bass management is a sort of subset of an active crossover. While the bass management options technically are an active crossover, you have a very limited number of options available. This is because bass management is specifically intended to be used to provide a crossover between "regular speakers" and a subwoofer. (The range of crossover frequencies you can pick is limited; you can't choose different types of filters, and you can't individually control the level of each output.) In contrast, a "full up active crossover" will usually allow you to choose between several different types of filters, will let you set whatever crossover frequency you like, and provide controls for adjusting the level (and possibly the phase) of each output.

If you need a relatively simple line level crossover (and don't have an XSP), you can use something like this:

www.hlabs.com/products/crossovers/index_files/Page384.htm

It's PASSIVE, so is somewhat limited in options, but it also shouldn't add significant noise or distortion....

And it's cheap - so it's easy to try for yourself.

The miniDSP can be programmed as an active crossover, and "pro" companies like Behringer and Rane make VERY flexible and configurable active crossover units (the kind with knobs, and display screens, and programming manuals).
The Behringer model lets you pick filter types from a menu, and actually shows you the filter slopes you've selected on a little built-in video screen.
(This makes life a lot easier if you're not very good at "seeing in your head what the numbers mean".)

If you're planning to "really get into active crossover design", it may also make sense to buy a unit like the Behringer for prototyping. It lets you try different settings and options very easily, and also allows you to see exactly what you have set. Then, when you find the settings that work perfectly for a particular project, you can build a simple (and non-adjustable) analog filter that duplicates those particular filter settings and options.

May 29, 2015 13:15:38 GMT -5 orthikon said:

I have 3.6R and thinking of using the XSP-1 to biamp. Is this possible using the bass management option?

Thinking of using 4x XPA-1s as I already have two or 4x XPA-1Ls if I can find a deal on them.

The stock 3.6R passive crossover settings are 200 HP 6db and 250 LP 18 db. know the XSP only does 12db so that issue aside is this doable?

If not, what active crossover are you guys using?

[DYohn]

Here's my utterly biased opinion. Bi-amping (or tri-amping or any other flavor of using multiple amplifier channels per loudspeaker array) is an absolutely necessary and important technique when the application requires extreme dbSPL levels, such as for live sound or in certain car audio applications. But in the home there is no point. And anyone who thinks they are achieving increased SQ levels because if it are fooling themselves. Also, any home user who thinks they can better cross over a loudspeaker system using active Xovers than what the OEM designer determined was appropriate for their system had better know what they are doing and have all the proper test equipment to verify unless they don't care about fried drivers over the long term. If you want to play with your system, sure. Go for it. That's why some manufacturers pander to the tweak crowd by using multiple binding post speaker connections. It's for fun if that's what you think is fun.

Best approach IMO: Buy the speakers you like. Buy a large enough amplifier to get the dbSPL levels you need in your home. Hook them up with a single speaker wire set and enjoy the music.

[jmilton]

^Another voice of reason. BURN HIM!