Excalibur's whimsical pile it high, turn it up question.

[Excalibur]

Right folks, this may be a thinking caps on scenario. Firstly, let me state that this isn't intended as a rig I'd use for a gig, more an exercise in what's possible.

My first visit to last year's Coalville sparked off an idea I've had for ages. It may work superbly well, it may be a pile of poo. I've long extolled the virtues of active crossovers, and I have a two way stereo one. I'd love a three way as well, but they don't often come up dirt cheap, and I haven't actually got a use for it, just a desire. Even after my recent clearout of speakers to Brian, I've still got a fair ( excessive? ) collection of cabs, and amps to power a few of them at once.

So, I want to create a three way stack. I know my two way stereo crossover will do three way mono, but that involves me reading the manual carefully, and a bit of rewiring, cos it's now a built in. Suddenly the other day, it hit me. The flash of inspiration, the bolt from the blue. Since I got my PV2600 and Studiomaster AX, I've now got everything I need already, haven't I? Right folks, try to follow this, cos it's tricky unless you get my drift early on.

The Peavey and the Studiomaster each have crossovers built in to enable them to drive subs, and pass on the higher frequencies to another amp and cabs. Well what if I used my active crossover to split that again, into mids and tops?

Flowchart.
Full range signal goes into Studiomaster from my mixer. I have the crossover enabled, and the low cut filter in. Thus this amp drives the subs with 30Hz to 150Hz, the crossover point. I then have a signal with everything above 150Hz in it, which would normally go straight into the amp driving my tops. No problem. Well what if I fed this signal into my active crossover, and split it there? Let's say I used 500 Hz as a crossover. ( I've no idea if this is a suitable point, it's just likely to be somewhere in the general area. )

150Hz upwards is fed into my active crossover, and split at say 500 Hz. This gives me 150Hz to 500 Hz coming out of the Low outputs, which goes off to the amp driving the mids. Everything above 500Hz goes to the top amp and cabs, which ought to give them an easy life.

It just looks so simple and blindingly obvious that I can't see the flaw. I'm sure there is one, but I haven't spotted it yet. :confused::confused:

It may sound awful, it may sound superb, I've no idea, but now that the idea's in my head, I want to give it a go.

OK folks, over to you. Opinions, advice and even criticism welcome, fire away. Just don't say " I can't see why you'd want to do this ". Simply because I can, and at times I'm a curious soul.

[DJ Jules]

I don't see why that wouldn't work. The only thing which would be missing which you'd get from a top end three way crossover would be phase alignment (i.e. the ability to compensate for tiny timing differences in the sound production from each set of speakers). You'd probably get away with this anyway for what you're talking about doing.

Incidentally this one doesn't break the bank (too badly - £70-£99 depending where you look):

http://www.gear4music.com/PA-DJ-and-Lighting/Behringer-CX3400-Pro-Super-X-Crossover/291

I'm not generally a fan of Berry kit, but I've seen this box working in a club where they've been through 2 mixers and 5 amps in 2yrs and this has survived :D

Julian

[Excalibur]

Incidentally this one doesn't break the bank (too badly - £70-£99 depending where you look):

http://www.gear4music.com/PA-DJ-and-Lighting/Behringer-CX3400-Pro-Super-X-Crossover/291

Julian

£70? £70?? Wash your mouth out with soap. Which part of "dirt cheap" confused you? :eek:
Only jesting, I've seen that one in use, and it impressed me a lot. One day maybe. Like I said, I've got no need at all for one, as I'd never use it on the road. It's just a whimsy, but it may be seen at Coalville next year, especially as Thunderbird 2 is a lot nicer than the old van for long journeys. Thanks for the input Julian.

[katman]

No reason why it shouldnt work, in fact its quite an elegant solution.

With your big subs, the crossover in them will give you 30-150Hz and a highpass output from 150Hz - 20K

Feed that into your 2 way crossover and the low output gets 150-500Hz and the High Output 500-20k

If you do a smaller gig, just feed the output of the mixer staight into your 2 way and you get 30-500 and 500-20k

All the crossover does in 3 way mode is daisychain the left and right sections as a mono crosover.
This is what you are doing with the internal crossover for the subs to the 2 way except in stereo and without buying any kit. :)

[Excalibur]

All the crossover does in 3 way mode is daisychain the left and right sections as a mono crosover.
This is what you are doing with the internal crossover for the subs to the 2 way except in stereo and without buying any kit. :)

You know Keith, I think I actually understood some of that. :confused: ( Probably the bit about not buying any kit ) :D:D:D Ta mate.

[DJ Jules]

£70? £70?? Wash your mouth out with soap. Which part of "dirt cheap" confused you? :eek:

For a crossover that is "dirt cheap" :zip: But yeah, I know what you mean - I refused to invest in one for years on the basis that there were better things to spend £70.00 on. £70.00 is still quite a lot of money, especially when you can do it for free :D

Julian

[Kernow]

Hi Peter, I have been doing practical experimentation on your theory using Zenith 2K5 (Amp) and Alto X23 (Crossover) into DA1300 & STA600 and early results indicate it's a positive solution. In fact it sounds rather nice to me.:)
It also does away with the need to compute collective impedances in the cabs.
Go for it I say :approve:

[Excalibur]

Hi Peter, I have been doing practical experimentation on your theory using Zenith 2K5 (Amp) and Alto X23 (Crossover) into DA1300 & STA600 and early results indicate it's a positive solution. In fact it sounds rather nice to me.:)
It also does away with the need to compute collective impedances in the cabs.
Go for it I say :approve:
Sorry for the late reply there, but thanks Rob. Logic/theory suggest that it ought to be possible to get a crisp clear sound with this rig and a bit of tweaking. Nice to know someone's already had success at it. Ta.