Active crossover advice for 1000hz biamp


Hi,

Im looking for an 2 way active crossover to divide the signal around 1000-1200hz so I can biamp with two tube amps. Lows will go to a 15 inch woofer and highs to a compression driver in a horn.
I was considering Rane, Bryston, Marchand, any advice will be welcome.

Thanks
Alan
128x128alanbrain
If you're bypassing the passive crossover, which is the only way this makes sense at this high a xover, you'll need to know more about the passive. Is it notched or shelved? Actives are usually 24dB/octave, fourth order or even 48dB/octave where passives are most likely first or third order, so there might be a narrow phase issue as well.

If the passive is unusual, there is a hybrid method, using the active one-way for the woofer and the passive for the upper drivers. If the speaker has biwire connections, that's not difficult, just going direct to the woofer.

You got a lot of homework to do before selecting a brand.
The speaker is custom made, so, there is no passive crossover. There are direct connections to the woofer and the horn. The compression driver is 109 db and the woofer is 99db. I was thinking of using an active one because I already have a good amplifier for the bass, EL34 20 watts and Im buying a SET one for the mid-highs something around 2-3watts.
Every horn I have ever worked with required equalization specific to that horn design, and I don't know of any off-the-shelf analogue domain active crossover with such capability. On the other hand, something that does digital signal processing like the DEQX could do the job... but it's hardly trivial to use.

Duke
dealer/manufacturer
Marchand can custom made one for you......is it not too high for crossover point the 1k-1.2k?
Well, I had in mind two cut options. One was around 700hz just above the cut off of the horn(the compression driver only goes down to 500hz) and the other around 1100hz. I rather prefer the 1100hz since I think the 700 is too critical area to cut but I can try.
Alan
Hey, how about a balanced Marchand along with a Manley Massive Passive EQ. Only another $5K, but all analog.
Alan, in order to do this correctly, you need to match amplitude levels, bring acoustic centres pretty close and, of course, choose the optimum xover frequency and, not least, the best acoustic xover slope... a few other things perhaps, but the above are really necessary.

So, can you find / buy an inexpensive tool ($¬200) in the form of a Behringer deq or their dsp? OK, it's audiophile non-approved BUT you can use it to determine all the optimal parametres of yr system. Once you know that, go ahead & buy the best xover. At least you'll know what to do with it!
Thanks Greg.
Thats a very good advice I will do it. I was checking
and you are talking about the behringer DCX, its the digital crossover. I was also reading and doesn't have so many bad comments. A lot of people is using them in their setups with little degradation and there is and upgrade path of the analog outputs!!!
Maybe I will stay with the DCX for a long time, for what I understand its lack of hi end is balanced on the other side with the tools you have to shape the sound on real time.
At the end like in everything in life there is no free lunch.
Thanks
Alan
Alan I am in the process of converting my speaker to use an active crossover. I have experimented a bit with a borrowed DEQX, and I can tell you that you DEFINITELY do not want this thing in your signal path. So, I plan to use the DEQX to help me find my settings. After that I will "hard wire" the crossover to the mids and highs with a Marchand, and use the DEQX for the woofer and subwoofer.

I do not wish to scare you, but with your horns you have a few considerations you may want to implement in your crossover.

1. Slope. I have found that steeper slopes sound better. Not true in a passive crossover, because you need a lot of components in the signal path to get a steep slope.

2. Phase and time alignment. I was surprised how much of a difference this makes. The sound suddenly becomes so much more coherent when it is properly time aligned. You may be able to do this by physically arranging the drivers, but it can be hard to do this (and achieve an aesthetically satisfactory result) with a horn.

3. Equalization. Ideally you only want to equalize below 200Hz and not above, because all equalizers introduce colorations of their own. You may want to consider some notch filters to take out some peaks in the F/R curve.

The success of your system will be VERY dependent on how succesfully you implement your crossover. More than anything else. A badly designed crossover with good drivers, amps, etc. will never sound good. I wish you the best of luck :)

Regards,

Keith
Look into the Accuphase F-25 Active crossover. It is an analog unit and can be 2-4 way.