You won't find it under that name, or was that a joke? I use one of these devices, and the fully active system I have heard also used one, you would not call the sound muddy! A friend of mine said that he found it hard to believe this system made my B&W 801s sound muffled.....I would be interested in the idea of replacing the op amps. There is a niche industry of people doing this sort of work to CX3400 crossovers but it seems an awful lot of money to spend on such a cheap box. My intention is eventually go to a dedicated x-over with no adjustments but the Behringer is more than OK at the moment.
I see what you mean about the polish, that should keep you busy for a long time!
I see what you mean about the polish, that should keep you busy for a long time!
That was just a typo. Rod Elliot does a nice Linkwitz crossover for the same price, but then you've got to factor in a case, hardware and power supply.
I'm more tempted by the Rod Elliot design as I can control the components that are used.
The only issue with the Rod Elliot design is that it's only a two way crossover so I would need 2 of them for six crossover points, The CX3400 seems to make sense even if I have to rebuild it.
I'm more tempted by the Rod Elliot design as I can control the components that are used.
The only issue with the Rod Elliot design is that it's only a two way crossover so I would need 2 of them for six crossover points, The CX3400 seems to make sense even if I have to rebuild it.
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I think I would agree with you for a final system, I look forward to hearing how that works out and which components/values etc you use. I have always viewed the Behringer as a "get you going" device but it exceeded my expectations.
Rod Elliot also states that the component vales are CRITICAL in order to minimise distortion, something that is almost impossible to achieve with variable resistors, manufacturers are yet to produce accurately matched pots.
Matching between R's and C's needs to be within 1%. 20% pots just don't cut the mustard.
Matching between R's and C's needs to be within 1%. 20% pots just don't cut the mustard.
I'm sure that is completely correct, and it is the way I will head too, but my ears tell me that the system I'm listening to is already outstanding, as was the other one that used the same crossover. I just put it forward as a way of getting going, if you are building amps and crossovers, on top of woodwork and french polishing, it might save you a bit of time and allow you to hear the music sooner. Please keep us informed of the Rod Elliot crossover, I might well build one myself.
Being almost completely useless at soldering I bought s/h BSS FDS360 crossovers for mine, had the limiters removed and replaced all the opamps with OPA2134s which I got dirt cheap of Farnell.
They were the last tube of 50 which were not RoHS compliant.
Could have used better ones (ie Linear Technology) but they would have cost 10x more (the 2134 came to about 80p ea) and would have needed extra bypass caps to avoid oscillation.
They were the last tube of 50 which were not RoHS compliant.
Could have used better ones (ie Linear Technology) but they would have cost 10x more (the 2134 came to about 80p ea) and would have needed extra bypass caps to avoid oscillation.
Just had a look at Nelsons wiki page.
Seems that at least some of his designs have something in common with my amps: Using a current transfer design instead of voltage transfer.
If it is possible to extrapolate from opamps this possibly means almost ridiculously high slew rates in the hundreds or thousands of volts per microsec rather than in tens of volts. At least those are figures I've seen in opamp data sheets.
Nelson looks a bit god-like too! ;-)
Seems that at least some of his designs have something in common with my amps: Using a current transfer design instead of voltage transfer.
If it is possible to extrapolate from opamps this possibly means almost ridiculously high slew rates in the hundreds or thousands of volts per microsec rather than in tens of volts. At least those are figures I've seen in opamp data sheets.
Nelson looks a bit god-like too! ;-)
Yes, they are still available but I needed a repair kit for one and a dealer I enquired with asked Scanspeak directly, they said they had stopped making the repair kit, and that the tweeter is obsolete (but still very good obviously). I did manage to find a repair kit and fix my tweeter but the remaining stocks are all that there will ever be - at least that's what I was told!
Catching up - the tweeter requires much less power than bass and mid-frequencies because it is a smaller,lighter driver and you are moving it far less (in terms of distance) than the other drivers. My own actives, as an example, cross over at 3.4kHz and have a 250w amp to the bass/mid driver and 75w to the treble unit.
A good way to set up levels is to *carefully* feed a signal to each driver just below the crossover point and then to the next driver just above and set levels from that.
A big advantage of going active is that if you blow a driver and it is unobtainable, it isn't the end of the world. If you can find one with similar performance, you can easily swap a pair out and adjust the settings to suit. Much, much easier than reworking a passive crossover.
Re piano black finish: ShinOBIWAN has written a series of very informative posts about doing this. I think it is somewhere in one of these two threads:
http://www.diyaudio.com/forums/multi-way/93218-lgt-construction-diary.html
http://www.diyaudio.com/forums/multi-way/52876-perceive-contruction-diary.html
I look forward to reading about this project as it progresses.
A good way to set up levels is to *carefully* feed a signal to each driver just below the crossover point and then to the next driver just above and set levels from that.
A big advantage of going active is that if you blow a driver and it is unobtainable, it isn't the end of the world. If you can find one with similar performance, you can easily swap a pair out and adjust the settings to suit. Much, much easier than reworking a passive crossover.
Re piano black finish: ShinOBIWAN has written a series of very informative posts about doing this. I think it is somewhere in one of these two threads:
http://www.diyaudio.com/forums/multi-way/93218-lgt-construction-diary.html
http://www.diyaudio.com/forums/multi-way/52876-perceive-contruction-diary.html
I look forward to reading about this project as it progresses.
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