JL Sargent Posted March 13, 2009 Share Posted March 13, 2009 I have gained so much info from this forum I thought I would share this active crossover, my setup, and my findings. I purchased the Behringer crossovers from "SWL" here a few weeks back and just now got it all hooked up. I had no XLR cables so I bought ends and made up several for this project. I wanted to try active crossovers and purchased 2 cabs which were destroyed in shipping (both horns out of mounts). I carefully calculated the volume w/ ports for my woofers from the web sites linked to by members here. I then rebuilt the cabs as woofer enclosures only. Running in 2 way stereo I have the top horns running off the little stereo 5 watt single ended triode amp. Bottom woofers on NAD transistor 30w per(late 70s maybe) Im also using the Nads preamp to feed the active crossover. The horns are 16ohm JBL 2441s 2" drivers/Community horns with a sensitivity of 111db and 8ohm Eminence 15" woofers at 101db sensitivity. So I knew the woofer was 10db behind out the gate. I started out with everything at 0db with no gain added or subtracted on any channel. I had both crossovers at 500hz. The crossover slopes are 24db per octave so I didnt know if to reverse the horns or not, so I did both. What fun it was to start playing with crossovers, gain, phase, and time (I just physically moved the speakers) until I got what I thought was the most out of it. What did I get: Truely awesome sound. Only with the volume wide open and my ear in the horns did I get any noticeable noise. I played with it all for quite a while and settled on woofers +4db, Horns -4db, horns in phase, crossovers at 475. The interesting this about all this to me how hard I had to work to make it sound bad. Taking the crossovers down to 100ish would do it. Or going way too high with it. Flipping the horns in and out of phase didn't make a whole lot of diffference just quieter out of phase (to my ears anyway) Quote Link to comment Share on other sites More sharing options...
JL Sargent Posted March 13, 2009 Author Share Posted March 13, 2009 In summary the Behringer units are not expensive yet seemed quiet and affective as an active crossover. I have been able to play with gain and crossover points to find where I liked them which will hopefully help me make passives to the same listening characteristics. Any recommendations about this project welcomed. Quote Link to comment Share on other sites More sharing options...
Marvel Posted March 13, 2009 Share Posted March 13, 2009 I had thought of an analog electronic crossover to get all the levels I wanted, and then make the passives to match. I think it was a great idea. So you built the bottom boxes with the woofers? Is that a little Magnavox on top? Bruce Quote Link to comment Share on other sites More sharing options...
JL Sargent Posted March 13, 2009 Author Share Posted March 13, 2009 Yeah Bruce, that is a little Maggie. Love that little amp. Wish I had another. Then I would try running top and bottom with em. Its interesting how little power those horns need to blow a persons head off! The cabs: The previous owner had the horns built in them. When I received them both horns had torn out of the cabs (way too heavy). I replaced the broken motor boards, then flipped the enclosure. For good deep bass those woofers needed all the available space. Quote Link to comment Share on other sites More sharing options...
seti Posted March 13, 2009 Share Posted March 13, 2009 Nice NAD I just picked up the 7250PE and it has changed my opinion on SS. 50WPC of NAD is like 200WPC in other amps. Well the NAD and MC250's have changed my opinion. Quote Link to comment Share on other sites More sharing options...
colterphoto1 Posted March 14, 2009 Share Posted March 14, 2009 Nice speaker lab there mang! Reminds me of my own little spot of heaven. Got the backlighting from window, big vise, comfy stool (I need to get one with a back), and all the conforts of home nearby. Great job with the speakers, horns, and using the digital to calculate the crossover points. Looking like a really neat project. Were you stick with 24 db/octave or did the Behringer allow you to experiment and you liked the steep slope better? Dig the avatar too! I think you're getting the hang of this stuff. Michael Quote Link to comment Share on other sites More sharing options...
JL Sargent Posted March 14, 2009 Author Share Posted March 14, 2009 Seti on the NAD: Its one of those under appreciated amplifiers and therefore still reasonably priced used. I have gone through/traded several amps over the years. Can't seen to let go of this one. Really like the sound as you pointed out. Michael, The Behringer's 24db per octave is not adjustable. Altering the slope would be a cool feature though. I'm guessing the sharpe slope helps with crossover determination however. Not much overlap there. In the avatar, thats my son deciding what sounds good and what doesn't. Everybody needs a second opinion and he freely gives his.[8-)] Thanks for the kind comments gentlemen. Quote Link to comment Share on other sites More sharing options...
Marvel Posted March 14, 2009 Share Posted March 14, 2009 ...and using the digital to calculate the crossover points Michael, the CX2310 is one of their analog crossovers.As I mentioned, I thought it would be a simple way to dial in the crossover points that sound the best, before committing to the caps and inductors. This one is really inexpensive, too. Quote Link to comment Share on other sites More sharing options...
JL Sargent Posted March 14, 2009 Author Share Posted March 14, 2009 These crossovers feature Linkwitz-Riley 24db per octave filters. So should the upper sides be in phase or 180 out based on that? Quote Link to comment Share on other sites More sharing options...
JL Sargent Posted March 31, 2009 Author Share Posted March 31, 2009 To followup on this: I found that around 750 crossover and 10 db of attenuation on the horns really sounded the best to me. I then found a couple of JBL 3110a crossovers that matched that spec. very closely with a 800hz crossover and available 10db attenuation on the horn. Swapped the active out and the passive in. Sounds great. Thanks to everybody that helped me get this going. Quote Link to comment Share on other sites More sharing options...
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