BiAmping with Active Crossovers

[napoleonblownafet]

Hi,

I currently have a build going on of a BiAmping box and need a little help. It's basically four separate power amps in one conventional-size enclosure with nice big heat-sinks. It also has:

- Separate regulated power supplies for L & R

- Speaker DC offset protection for both tweeter and woofers

- Soft start - no speaker thump

Each power amp is about 100w and is of my own design, but is based on tried and tested long-tail-pair / three-stage architecture, solid-state drivers and is perfectly stable and not prone to oscillation. Very good damping factor etc. DC offset is tuneable down to a few millivolts.

I would love to buddy up with someone who owns or has built a speaker setup with an active crossover in it; two-way prefereably, but I wouldn't rule out trying a tri-amping setup at some stage. I would like to bring this to Kegworth either this or next year, so if this sounds up anyone's street or you know anyone who would like to get involved with something like this, then let me know.

I'm based in North-Surrey / South-London, if that helps.

Thanks all, NAP.

 

[MF 1000]

Hi Nap 

I run a 5 way active setup with modified speakers ( Volt 18 " driver bass, KEF 104.2 - passive xovers, Fostex supertweeters) using two sets of monoblocks, and 3 other power amps controlled by two Behringer DCX2496 digital crossovers.

just ask for any help etc - unfortunately not nearby as im in N Wales. 

 

[greybeard]

Hi Nick I run a 3 way active setup , which I tri-amp with 6 channels of Hypex ncore modules all in one enclosure, and use DCX 2496 digital speaker management unit for xover and DSP. It was originally a 2 way active set up, to which I have now added a mid, to each speaker in a separate cabinet. So can be used 2 or 3 way. 3 way is better to my ears.

 

[Tony_J]

Hi Nick

I am running 2 active systems - one is a 2-way, using Alpair 10.3 full range drivers from 300 Hz up and Tang Band 8" woofers for bass, the other is a 3-way system using Tannoy 8" Dual Concentric drivers for mid and treble, and pairs of Tannoy 8" drivers for bass. Using Class D amps in both systems - the 2-way uses nominally 125W+125W stereo modules from XKitz, the 3-way uses four IcePower 50W+50W amps. The crossovers are all based on miniDSP DDRC-24 units with Dirac capability - the 3-way system uses an additional miniDSP unit to split off the bass from the mid+bass output of the DDRC unit.

There are write-ups of my various skirmishings with active in the DIY section, but ask away if you need info/help.

 

[napoleonblownafet]

Thanks folks

I'm trying to scratch a bit of an itch here - which is that I hear a number of people say they'd get into active crossovers if they didn't need multiple power amps and all those effing cables etc.

I've not built an active system myself, but I have built amplifiers that can power them.

Basically, I have the means of putting everything you need - except the crossover module itself - in one integrated box. It can even have a phono stage and pre-amp in the same box if you want it. I can offer this as a kit if anyone wants to build one.

Just think of the Wife Acceptance Factor

 

[bencat]

Hi Nick

My electrical talents are strictly limited sowhen i decided to get in to an active set up I had to use things that were allready built and easy to connect . In the end I made a first system of a pair of KEF 103 Reference speakers with MiniDSP DDRC 24 unit attached and then a pair of modified Quad 405 power amps . Later due to to an evil suggestion fron TonyJ I then bought a second pair of of KEF 103 and stacked them using the bottom ones for assisted bass only with the Quads and the DDRC 24 . Wish you had been able to offer the one box x 4 amp solution much sooner would have been that much easier but i got there in the end and what I ended up with sounds great even if i do say so myself as to date no one other then me has listened to it .

 

[napoleonblownafet]

Thanks Bencat

I'm going to keep on with this and see if anyone expresses an interest. I'm not trying to sell anything at the moment - rather see if this has legs.

Each year there appears another DIY kit for active crossovers. I was at Burning Amp last November and Nelson Pass announced his. It's all good stuff and I think a two box solution i.e. one amp and one x/o could appeal to a lot of DIYers, if not their wives and/or girlfriends!

Thx, NAP

 

[napoleonblownafet]

Hi Nap 

I run a 5 way active setup with modified speakers ( Volt 18 " driver bass, KEF 104.2 - passive xovers, Fostex supertweeters) using two sets of monoblocks, and 3 other power amps controlled by two Behringer DCX2496 digital crossovers.

just ask for any help etc - unfortunately not nearby as im in N Wales. 

Hey Keith

I had a look at those Hypex Modules. How do they sound? My power amps are Class B and Class A at the same time. Not overbiased A/B, rather two output stages together; one in B and one in A. Makes a bloody nice noise if I say so myself, but sucks a bit more power than a class D

How big's your enclosure? Pictures welcome ;-)

Ta NAP

 

[MF 1000]

Hi Nick 

its Colin (Greybeard) who runs the Hypex modules....I'm mainly on 'trad' amps  

2 x Behringer KM750 bridged monos 750 wpc for the sub/bass speakers

Musical Fidelity A370 185 wpc for mid bass

MingDa 845 valve monoblocks 18 wpc for midrange

2 x SMTL (cheap Chinese SState) 50 wpc for tweeters & super tweeters 

here is a pic of the main rack that holds all amps and crossovers except the 845's and preamp

 

[napoleonblownafet]

Thanks Keith, that's quite something. Worthy of comment certainly. Thanks for sharing - and yes, sorry I read the comments too quick and mixed you guys up.

Colin, would love to see your "miniturised" version if you get a chance to take a pic.

Thanks again, NAP

 

[dave]

Hi, this will be active one day, it is creeping to the top of the pile. It will have 2 amplifiers and analogue eq and crossover of my own design. I like to rat's nest, but tempted to put this straight to a PCB after lots of simulation.



Sounds like an interesting amplifiers would be interested in seeing a circuit if that is allowed?

 

[Speedskater]

One great thing about DIY loudspeaker building using a DSP active crossover is.

You can program in some different crossover curves as 'scenes'. Then have someone else randomly pick a scene. Then you can make ears only decisions as to which is the best choice.

Another great thing is you don't need a lot of different expensive capacitor and inductors to try different curves.