Bi-amping

[MoJ]

Hi,
just done a search but nothing fruitful came of it.
Im interested in a bi-amped gig rig, via seperates (ie preamp and power amp) of around 500w and just wondered how to go about it. I know that Ill need a crossover of some kind and the preamp side of it isnt the issue at the moment.
Im not so much after recomendations as such although if anyone has strong views as to what to try or stear clear of then Ill certainly take heed. If anyone thinks that a particular all-in-head is worth noting then please suggest. Otherwise Im just interested to hear what, if people are doing this, use.
Ive seen a couple of power amps with bi-amping facilities [url="http://www.guitarampkeyboard.com/en/yamaha-p5000s/67308"]here[/url] where you can put this into parallel mode which feeds both sides from the same source, and then use a and high pass filter set to what frequency (and below) you choose to cut out of the signal to either output, and [url="http://www.peavey.com/products/browse.cfm/action/detail/item/116312/number/00512180/cat/91/begin/1/PV%AE+2600.cfm"]here[/url] which just uses a 150Hz crossover. These are if anything only examples but does anyone know if this is a viable solution, or would it be better to have a seperate crossover and if so what?
Oh, and one final thing, as this is what started it all off, does anyone have any experience of the Bass Podxt Pro? Maybe thats a different thread altogether,but to have a selection of different amp sounds (accurate or not) and a bunch of other things including a bi-amping facility would drastically cut a lot of costs down and then I would only need a stereo power amp.
Sorry for the drivel but would like to hear peoples views and what you use.
Thanks
Andy

Sorry, meant to add, i anything Im realy just trying to get ideas of whats out there and whats being used so as I can consider all options and make sure I haven missed anything.
Thanks

Edited June 5, 2007 by MoJ

[BOD2]

I've not actually used a biamped setup but there are a couple of considerations. Firstly, note that most bass cabs are "full range" (for bass guitar anyway) therefore if you use standard cabs you lose some of the advantage of biamping. By that I mean that part of the reason to biamp is to optimise the frequencies sent to each cab so that each cab handles only those ferquencies within its ideal range. If the cabs are full-range then this doesn't really make sense.

Secondly, I suppose is to ask why you actually want to biamp in the first place ? Does this meet a particular need you've identified or do you just want to try it out ?

I use the Bass POD XT Pro and can probably help with the operation of that if you have a specific question, but I don't biamp with it - I feed the PA directly from one output and a full-range monitor from another output.

[MoJ]

Hey BOD2,
thanks for a prompt reply!
Well,I guess I mainly want to try it out really. Having greater control over individual parts of my sound interests me greatly. Its an interest that was re-awoken from starting work at a guitar shop where they have the Bass Pod Xt Live and thusly prompted to find more info on it on the Line 6 site, and the Pro version caught my eye.
Spending far too much time on the internet that night I learnt of its many functions including the bi-amping and that has spurned me to looking into other ways of doing it, rather than rely on getting high hopes for the Pro. It does sound tempting though for the price.

So, as for bi-amping, I would like to educate myself its benefits and disadvantages and I guess there is no way better than to do it or hear it being done. I do at some point hope to build a/some BFM cabs and bi-amping has got me looking into a sub/top comination, so I guess having the means to do so wouldnt be a huge stretch.
Something that Ive been thinking about only today is that if bi-amping is applied in an application,then surely it is a case that you are enabling speakers to work more easily as they are not trying to replicate a vast array of frequencies at any given moment. I think what I mean by that is that while you have low end frequencies causing speakers to move slowly, at the same time high end frequencies are trying to oscillate the speakers faster, and at different rates. Im imagining 2 sine waves of different frequencies being added together giving you an undulating wibbly line (kinda like a ring modulator) which IIRC also weakens the signal to an extent? That may not be the correct way of explaining that....
I would imagine with bi-amping you could find an equilibrium of bass and top-end easier without one overpowering t'other?

As for the XT Pro, you obviously use it live then. Just that Id heard at least of the previous incarnation not really up for the job. How easy do you find it to use? Must admit Im not one for trawling through masses of sub-menus..
Do you use one of the floor pedals live to engage diferent patches? Im not fussed about accuracy of the moddeling, just so long as I can get one good amp sound thats enough but like the idea of having the multifx angle.
Oh, and how's the compressor hold up? I guess its not studio quality. Is that pre or post EQ in the chain?

Sorry for bombardment of questions. Im sure Ill have more but thought while Im here I should ask.
Thanks BOD2
Andy

[MoJ]

Sorry, just to add someting else to the melting pot that I know Im probably getting wrong, is connected to balancing low and high frequencies in that if I increase the sub on my PC speakers (I know this is a weak analogy) I find it impossible to drown everything out with too much bass.
Now I know that the PC speakers are designed differently and to take a more even range of dynamics, but I would imagine that there must be [i]some[/i] comparison to made in bi-amping a bass guitar signal. Surely even in a full range speaker setup.
Does it make a difference Id be using say a 2 x10 and 1 x 15 of commercial cabs?
Thanks
Andy

[bass_ferret]

The most famous exponent of bi-amping was the Ox. He started off using Marshall and Hiwatt valve amps with one set having the bass turned up full and another set with the treble turned up full. The full history of the Ox's search for sonic nirvana via bi and even tri amping should be available on the internet somewhere on a Who website. Ashdown used to make a range of cabs with horn loaded bass cabs for John.

I tried it myself with two Peavey bass combo's which had built in crossovers but it did not work very well. There always used to be Peavy pre-amps with built in crossovers but I've not looked recently.

[bassbloke]

I tried bi-amping my rig years ago. Whilst the bottom end through a 15was certainly impressive, the top end through 10s was lacking. I was able to rig up a decent compromise using an SWR SM400 whereby I sent a full range signal to a 2 x 12 and a sub signal (below 120Hz) to a 1 x 15. I reckon you might the results of this approach more than a complete high/low split

[MoJ]

[quote name='bass_ferret' post='12133' date='Jun 4 2007, 10:45 PM']The most famous exponent of bi-amping was the Ox. He started off using Marshall and Hiwatt valve amps with one set having the bass turned up full and another set with the treble turned up full. The full history of the Ox's search for sonic nirvana via bi and even tri amping should be available on the internet somewhere on a Who website. Ashdown used to make a range of cabs with horn loaded bass cabs for John.[/quote]

Yeah, I think it was seeing bits and pieces on Johns' rig that may have even sparked off this interest. Im no real fan of the Who but man did John have an awesome tone.
Its one of those things that every now and then Im reminded of and try and look further into but being a techincally inhibited dunce who gets confused at the sight of a few ohm ratings etc Ive know idea where to start sometimes!

Thanks for the info the Mr Ferret!
Andy

[BOD2]

OK, I see where you're coming from.

To get any benefit you would need to have cabs with different frequency ranges and set the crossover to match those ranges.

There doesn't appear to any problem with speakers reproducing a vast array of frequencies but every speaker cab has a finite frequency range and asking that cab to reproduce frequencies outwith that range is a waste of amplifier power. So the primary object of bi-amping is to get more efficiency out of the speaker cabs you have by not having them waste amplifier power on frequencies they are not efficient at reproducing.

Using, say a 2x10 and 1x15 would not really be efficient, as both would have very similar frequency ranges (in fact sometimes the 10" cabs actually have a lower frequency response that 15" cabs, depending on how they're designed) so you wouldn't be getting the best out of the setup. With these cabs you'd probably get very similar, perhaps better, results driving both cabs with the same signal.

I have no problems with the Bas POD XT Pro. But then I have only setup 3 or 4 sounds for use live (it seems overkill to have more than this for live work). Switching between them involves pressing one button on the POD, or one switch on a foot controller. So once your sounds are setup there's no difficulty in using them at all. You can tweak the tone live using a full set of rotary controls (exactly the same as the tone controls on any amp) in no time at all.

You only use the menus and sub-menus when creating new sounds and storing them - which isn't something you'd normally do live !

I use a Behringer FCB1010 foot controller live (a standard MIDI one). I can do everything from that.

There's a separate topic [url="http://basschat.co.uk/index.php?showtopic=669"]here[/url] about the accuracy of the amp models.

There are two compressors on the Bass POD XT pro. A fixed one that's post most of the FX (you can actually move some of the FX around) and another optional one that's pre-FX. They seem to do the job OK.

You might be able to download the Bass POD XT Pro user manual from the Line6 website. That will help give you a good idea of what it can do.

[Stewart]

I use tri-amping for my 'stereo system'...

The good news is that the system used by most analog crossovers is so simple to do well that you might just as well get a Behringer or Samson as a more expensive make.

Or make one/build a kit...
There's one here (second item down):

[url="http://sound.westhost.com/projects-3.htm"]http://sound.westhost.com/projects-3.htm[/url]


Passive (in the speaker) crossovers are a nasty mix of coils and capacitors - nowhere near linear, and probably 18dB/Octave cutoff slope at the very best, whereas the Linkwitz-Riley filters used in most rackmount crossovers are (or should be) better in every respect and also have slopes of 24dB/Octave - meaning you can push both/all drivers harder and closer to their ideal frequency ranges.

It's the single most staggering improvement I've ever made to my audio gear.

Whether or not it's worth it for a bass rig, I couldn't say - but try it on your stereo if you can beg another stereo amp and don't mind a bit of soldering inside your speakers!

(It's worth having identical amps if you want to get serious, but you'll probably be blown away even with sub-optimal matching)

[MoJ]

[quote name='BOD2' post='12154' date='Jun 4 2007, 11:02 PM']OK, I see where you're coming from.

To get any benefit you would need to have cabs with different frequency ranges and set the crossover to match those ranges.

There doesn't appear to any problem with speakers reproducing a vast array of frequencies but every speaker cab has a finite frequency range and asking that cab to reproduce frequencies outwith that range is a waste of amplifier power. So the primary object of bi-amping is to get more efficiency out of the speaker cabs you have by not having them waste amplifier power on frequencies they are not efficient at reproducing.

Using, say a 2x10 and 1x15 would not really be efficient, as both would have very similar frequency ranges (in fact sometimes the 10" cabs actually have a lower frequency response that 15" cabs, depending on how they're designed) so you wouldn't be getting the best out of the setup. With these cabs you'd probably get very similar, perhaps better, results driving both cabs with the same signal.

I have no problems with the Bas POD XT Pro. But then I have only setup 3 or 4 sounds for use live (it seems overkill to have more than this for live work). Switching between them involves pressing one button on the POD, or one switch on a foot controller. So once your sounds are setup there's no difficulty in using them at all. You can tweak the tone live using a full set of rotary controls (exactly the same as the tone controls on any amp) in no time at all.

You only use the menus and sub-menus when creating new sounds and storing them - which isn't something you'd normally do live !

I use a Behringer FCB1010 foot controller live (a standard MIDI one). I can do everything from that.

There's a separate topic [url="http://basschat.co.uk/index.php?showtopic=669"]here[/url] about the accuracy of the amp models.

There are two compressors on the Bass POD XT pro. A fixed one that's post most of the FX (you can actually move some of the FX around) and another optional one that's pre-FX. They seem to do the job OK.

You might be able to download the Bass POD XT Pro user manual from the Line6 website. That will help give you a good idea of what it can do.[/quote]

Cool,ok.
Well,what you're saying about bi-amping kinda makes sense. Thanks for the advice on hat BOD2.
Id still like anyone else's views on this though, if anyone has any. Not that I dont believe BOD2, but Id like to get as many opinions and facts as possible.

Thanks also for the view on the XT Pro. Ill look into that Behringer footpedal and check it out. So it can be operated by any midi foot controller? Useful to know!
I like the fact that the effects are moveable too. Not sure how many Id need but I think its always good to have more than you need, just in case, but I also have a nice wah and proper valve overdrive pedal I could just never do without. The fact there are 2 compressors too is cool. Out of interest, are they fully functioning or more auto compressors?
I tried to download the user manual for it, but I cant seem to find it on there. Most companies usually have them in .pdf form and I usuall incoporate them in my research into products. Its annoying when companies dont do this!
Guess Ill have to look at the Live version manual as I think they're meant to be one and the same essentially.
Thanks again BOD2,
keep those posts coming people though
Andy

Just thought,how good would an XT Pro sound with an all valve power amp?Hmmmmmm....

Edited June 4, 2007 by MoJ

[Mr Bassman]

I tried bi-amping a few years ago with good results.
I was playing a Wal 5 and wanted a high-fi type full range system and aquired an ampeg SVT 400T stereo head that had a built in crossover.
I tried various cabs for tops and bottoms but also had an Ampeg SVT100T combo that had 2x8"" speakers plus tweeter.
I bridged the 400 into an 8 ohm 400 E.V.15 and took the top signal into the effects return of the 100T. Brilliant!
Another setup was with a Peavey Megabox which had 1x15 and 2x8 with passive crossover built in, or bi-amp imputs. Not as hi fi as the previous, but then I went stereo with 2 Megaboxes.
Then I got rid of it all for an SWR 400 and 2 E.V.15's.

One thing if you are going to experiment with different cabs, you'll need a variable active crossover.

[BOD2]

Best to get as much advice as you can - as I said to begin with, I've not actually used a biamped setup so I'm only giving you the theory and not the practice.

All of the PODs are standard MIDI devices and you can control just about any parameter from a MIDI controller.

Not all of the effects are movable but you can put EQ, modulation and delay/reverb before or after the amp model.

The main compressor (controllable from a "real knob" on the front panel) is based on the LA-2A valve studio compressor. It's pretty much an "auto compressor" though as you only have that one knob to increase or decrease the amount of compression. This one is post EQ.

The other compressor(s) can be selected as the "stomp box". The stomp box can be set to a compressor, or distortion, or auto wah, or synth. This means you can't use this compressor at the same time as distortion or auto-wah, for example (bit you always have the main compressor available). This multi-function thing is always a limitation on multi-FX units. If you want to use the compressor here, however, you can choose a Boss CS-1, MNXR Dyna-Comp, or one of Line6's onwm models, and these have several controls available.

I've PM'd you about the user manual.

[The Funk]

[quote name='bassbloke' post='12149' date='Jun 4 2007, 11:01 PM']I tried bi-amping my rig years ago. Whilst the bottom end through a 15was certainly impressive, the top end through 10s was lacking. I was able to rig up a decent compromise using an SWR SM400 whereby I sent a full range signal to a 2 x 12 and a sub signal (below 120Hz) to a 1 x 15. I reckon you might the results of this approach more than a complete high/low split[/quote]

This is similar to what I do.

My Aguilar DB680 preamp has a built-in crossover. I use the low crossover out for real low end to my 1 x 15 and I run the 2 x 10 full range. Sounds awesome like this.

[BigRedX]

I'm probably about to switch back from bi-amping to a more normal set up. My previous rig was bassed around a Peavey BassFex processor that included a variable crossover and the ability to add different effects to either side of the signal path after this. For the music I was playing at the time - live dance influenced pop-rock this setup was invaluable in letting me get the sounds I needed. Nowadays I play in a much more conventional band the necessity to use a bi-amped system has lessened. Recently I tried running my rig completely full range and get a much better sound out of it. I would consider bi-amping but only in the way The_Funk has described with one full range output and a second bass only. However AFAIK only the Aguilar DB680 has this facility. It might be possible with some creative thinking on a BassPod but it would involve at least one piece of extrenal kit... Unless you have a distinct need for high and low frequency effects routing I'd not bother.

[BOD2]

[quote name='BigRedX' post='12478' date='Jun 5 2007, 01:44 PM']I would consider bi-amping but only in the way The_Funk has described with one full range output and a second bass only. However AFAIK only the Aguilar DB680 has this facility. It might be possible with some creative thinking on a BassPod but it would involve at least one piece of extrenal kit...[/quote]

Hmmm... the Bass POD XT Pro manual suggest that when Bi-amp mode is enabled, the split "bi-amped" signal is sent to the "Unablanced Analog Out" jack plug connectors. There are two of these - one gets the Hi and one gets the Lo. It further suggests that the "Balanced Aanalog Out" XLR connectors are not affected by the bi-amp mode.

If this is correct you could get a lo-only bass signal from one of the "Balanced Anolg Out" on a jack plug at the same time as a full-range signal from either of the "Unbalanced Analog Out" XLR connectors.

Of course, sometimes these manuals are not correct....

[BigRedX]

Certainly on my BassPod XT Pro the balanced outs reflect the jack outs - I'm also pretty certain it says this in the manual.

I haven't had a chance to see what happens at the digital outs yet...

[BOD2]

[quote name='BigRedX' post='12501' date='Jun 5 2007, 02:02 PM']Certainly on my BassPod XT Pro the balanced outs reflect the jack outs - I'm also pretty certain it says this in the manual.

I haven't had a chance to see what happens at the digital outs yet...[/quote]


I'm just reading from the manual (which isn't always a good thing). Bi-amping is detailed in the section that describes the function of the unbalanced outs. It does not mention bi-amping when describing the balanced outs. Also, the labelling on the back of the unit has "Bi-amp mode hi/lo" beside the unablanced outs but nothing beside the balanced outs.

As I said, I've never tried this so I don't know for sure what happens but the manual is [i][b]suggesting[/i][/b] (though not actually stating) that these outputs are different when biamping.

Note that this applies only to the rackmount XT Pro and not the kidney bean XT.

[Dan_Nailed]

Bi-amp capable heads that spring to mind are the Harthe HA5000 and HA7000 and the Ampeg SVT4PRO that have built in crossovers.

I used to run a HA5000 into a Peavey 4x10" and1x15" and it always seemed like I was wasting the speakers. Running just lows into the 15 and just highs into the 10s ignored the quality that those speakers impart on the full frequency range, like punchy lows on 10s and scoopy mids on 15s.

Just IMO.

[MoJ]

[quote name='BOD2' post='12430' date='Jun 5 2007, 12:49 PM']Best to get as much advice as you can - as I said to begin with, I've not actually used a biamped setup so I'm only giving you the theory and not the practice.

All of the PODs are standard MIDI devices and you can control just about any parameter from a MIDI controller.

Not all of the effects are movable but you can put EQ, modulation and delay/reverb before or after the amp model.

The main compressor (controllable from a "real knob" on the front panel) is based on the LA-2A valve studio compressor. It's pretty much an "auto compressor" though as you only have that one knob to increase or decrease the amount of compression. This one is post EQ.

The other compressor(s) can be selected as the "stomp box". The stomp box can be set to a compressor, or distortion, or auto wah, or synth. This means you can't use this compressor at the same time as distortion or auto-wah, for example (bit you always have the main compressor available). This multi-function thing is always a limitation on multi-FX units. If you want to use the compressor here, however, you can choose a Boss CS-1, MNXR Dyna-Comp, or one of Line6's onwm models, and these have several controls available.

I've PM'd you about the user manual.[/quote]

You know, Im starting to GAS quite badly here!
Thanks Alan,you've been really helpyful here. Thanks for the PM too. Like I said in my reply to you Ive been reading through the Live version manual and thats definitley got me interested. Would be great to see what other features the Pro version has and, as you mention about the bi-amping possiblites lower, what Line 6 have to say about that too.
I may have to 'borrow' the XT Live and see what it sounds like. No, seriously, Im activley encouraged to do so at this shop as part of 'product knowledge'. I love my new job!

[quote name='The Funk' post='12443' date='Jun 5 2007, 01:08 PM']This is similar to what I do.

My Aguilar DB680 preamp has a built-in crossover. I use the low crossover out for real low end to my 1 x 15 and I run the 2 x 10 full range. Sounds awesome like this.[/quote]

This definitley sound like a good idea to me. I guess its more of a case that with a set-up like this, you are re-enforcing the low end as opposed to splitting the signal in to just highs and lows,but still alowing for greater control over the low end.
I think the Yamaha power amp I put a link for in my initial post gives you option similar to this

Thanks guys, these are all very cool ideas to think about (whilst increasing my GAS list!). I shall continue my research while I await some more responses.

[Kiwi]

The GK stuff employs biamping too but splits between ultra high frequencies above 5KHz and everything else. It sends the ultra highs to a 50w power amp and then to a tweeter, the lows get sent to the 480w power amp and through to the woofer where they can be boosted for extra growl. To my ears at least, this sounds like a very effective system. GK extension cabs can be connected with the 4 way proprietary speakon cable and run in the same way, or a full range cab can be attached in the usual fashion with a regular speaker cable.

[Bill Fitzmaurice]

[quote name='MoJ' post='12132' date='Jun 4 2007, 05:44 PM']Does it make a difference Id be using say a 2 x10 and 1 x 15 of commercial cabs?
Thanks
Andy[/quote]
All the difference in the world. Bi-amping (or tri or quad for that matter) is de reguer in the upper end PA genre, where speakers are designed to work with high efficiency, in terms of both SPL and pack space, over a relatively small bandwidth, with no overlapping coverage. That's pretty much the opposite of how most bass cabs are designed, so the advantage of bi-amping with typcal electric bass cabs is greatly reduced.

[MoJ]

[quote name='Crazykiwi' post='12643' date='Jun 5 2007, 07:35 PM']The GK stuff employs biamping too but splits between ultra high frequencies above 5KHz and everything else. It sends the ultra highs to a 50w power amp and then to a tweeter, the lows get sent to the 480w power amp and through to the woofer where they can be boosted for extra growl. To my ears at least, this sounds like a very effective system. GK extension cabs can be connected with the 4 way proprietary speakon cable and run in the same way, or a full range cab can be attached in the usual fashion with a regular speaker cable.[/quote]

Thanks Kiwi,
the GK heads are something I had breifly thought about but not looked into yet. If only because Im sure Justin Chancellor of Tool uses the top-of-the-range head they do and when I saw them last year,he had a huge sound whilst still being able to hear his gravely overdrive above it all (though Im sure the Hammersmith Apollo's PA had something to do with it), yet it wasnt boomy like it was room dynamics.
I didnt realise that the crossover in the heads was at 5 kHz though. Seems quite high to me. I dont doubt you, its just that I have a tweeter in my 4 x10 (which apparently crosses over at 5 kHz) and being as I use overdrive myself quite a bit I turn the tweeter off as it sounds harsh to me.
Still,something to consider.
Thanks,
Andy

[MoJ]

[quote name='Bill Fitzmaurice' post='12650' date='Jun 5 2007, 07:48 PM']All the difference in the world. Bi-amping (or tri or quad for that matter) is de reguer in the upper end PA genre, where speakers are designed to work with high efficiency, in terms of both SPL and pack space, over a relatively small bandwidth, with no overlapping coverage. That's pretty much the opposite of how most bass cabs are designed, so the advantage of bi-amping with typcal electric bass cabs is greatly reduced.[/quote]

Ah,excellent. The man himself. I was going to join your forum to get some answers so Im glad you saw this post here Bill.
Ive been looking at your site for a while now trying to decide what to get plans for and now the idea of bi-amping has occured to me I was trying to work out what sub and top would suit me best for this application.
Would your designs work in a bass guitar bi-amp rig, or is the anwser still a case of not really worth pursuing?
If its any help Bill, I play 4 string tuned down to low B so I was swinging toward the omni 15 for its lf (correct abbreviation?) and I know that that has internal 3 way crossover in it for the differing speakers. Would a Titan and Omni 10 bi-amped be feasible?
Apologies if this is something I should really be asking over at your site, but thought now you've seen it here I should ask.
Thanks,
Andy

[warwickhunt]

I'd certainly try before you buy with regard to bi-amping as I've tried it numerous times over the years and I've 'never' been satisfied with the results.

Tried it with the stand alone heads (GK 800rb) to preamps and separate power, with a variety of cabs (2x10 & 1x15 to 4x10 & 2x15 and all combinations in between), none ever did it for me as they all lacked something in the range that the crossover was set.

I believe that Bill, Alex and various knowledgeable bodies were able to explain why this was but the upshot was still that I disliked the sound of bi-amping with typical bass cabs. That isn't to say that specifically designed cabs wouldn't do a better job but if it were me I'd want to give it a try before I built or bought cabs. If the intention is to use this rig on a large stage with a quality PA you do have to ask yourself what's the point? The PA will be doing all the bi/tri-amping you require. If we are talking pub/club gig... will you or the audience get the true benefit?

Simply an opinion and observation!

[Jack]

[quote name='MoJ' post='12651' date='Jun 5 2007, 07:51 PM']I didnt realise that the crossover in the heads was at 5 kHz though. Seems quite high to me. I dont doubt you, its just that I have a tweeter in my 4 x10 (which apparently crosses over at 5 kHz) and being as I use overdrive myself quite a bit I turn the tweeter off as it sounds harsh to me.[/quote]


The GK heads have an inbuilt 'boost' circuit that adds quite a bit of growl and dirt, this is located AFTER the crossover on only the woofer amp. The result is overdriven speakers and a pristine clean tweeter.

In other words, it was designed specifically to combat what you mentioned: drive sounding harsh on tweeters.

Of course, you can only use the inbuilt boost, which you may or may not like. The effects loop is full range.