dan4510 Posted August 12, 2010 Share Posted August 12, 2010 I wanted to experiment with tri amping for quite a while. Bought a kit from marchand with 24db slopes and cross at 450 hz and 4500 hz. Replaced the cheap opamps with high dollar ones and really looking forward to hooking this up. Am also building a custom wood box out of red oak to put it in. As I go along I will post pictures. Will give me incentive to finally stain all areas of the speakers so they look good. Dan Quote Link to comment Share on other sites More sharing options...
Groomlakearea51 Posted August 12, 2010 Share Posted August 12, 2010 When you get it done, round up a pair of CT-125 tweeters and test it with those (if you have not done so already). I'm interested in your results vis a vis the 4500 point. Quote Link to comment Share on other sites More sharing options...
Mike Dubay Posted August 12, 2010 Share Posted August 12, 2010 Keep a good thread going on this. I almost with with the Marchand kit, but with with an Ashly buildt up unit instead. With the selenium DX-250's, I crossed by Cornscalas at 400 Hz and 4500 Hz. I'm looking a second active crossover and am interested. Quote Link to comment Share on other sites More sharing options...
brians7 Posted August 18, 2010 Share Posted August 18, 2010 I have a Marchand XM44 and used to Bi-Amp LaScalas 2-way with ALK universal networks crossover at 700Hz. And is works great. Quote Link to comment Share on other sites More sharing options...
dan4510 Posted August 29, 2010 Author Share Posted August 29, 2010 Ok, here is as far as I have gone. Built the four boards. Now am gonna build a red oak box to put it in that is 3" tall, 12" deep, and 17" wide. Ordered the power supply already built. Also upgraded to almost the best opamps. After research it turns out that the opamps used can be a be determinate of the sound produced. So I researched them and the almost best was $4 an opamp opposed for the best at $9 an opamp. It seems that the difference between the two is not much. However, the difference between the opamps supplied with the kit and the $4 ones I bought is huge. Found out the opamps provided with the kit can be bought for less than 50cents each, so it was a worth while upgrade. Crossove points will be 450 and 4500 at 24db/octave. I bought other crossover modules to experiment with at 400, 500, 3000, 3500, 4000. My midrange is a JBL 2482 on a jbl 2380 horn. Frequency range is 300-5000. My tweeter is JBL 2404 with frequency range of 3000-20,000. I picked the 4500 point to try first to try and keep the most sound produced by the midrange and it starts pooping out at 4800 or so. Right now I have no crossover on the high point of the midrange, I just let the drive go out on its own and use a capacitor to block under about 4400 for the tweeter. It sounds great, but I think it will be even better with the electronic crossover at all crossover points. Dan Quote Link to comment Share on other sites More sharing options...
dan4510 Posted August 29, 2010 Author Share Posted August 29, 2010 Also bought the best pots I could find, were about $12 each, far beyond what comes on any manufacturere equipment. spent several hours researching this to make sure I had the right curves, values, etc. The pots are the round things at teh top of the photo lined up. Use two for midrange adjustment, two for tweeter adjustment. Midrange is 117d/meter/watt efficient, tweeter is 107d/m/watt efficient. Dan Quote Link to comment Share on other sites More sharing options...
dan4510 Posted August 29, 2010 Author Share Posted August 29, 2010 And to be honest, this was a job. I found out how much my hands shake, how blind I am and how hot the end of a soldering iron is, not once but several times. One last bit of advice, DON'T SOLDIER WHILE WEARING SHORTS! Dan, recovering from the pain.... Quote Link to comment Share on other sites More sharing options...
djk Posted August 30, 2010 Share Posted August 30, 2010 A JBL 2482 on a 2380 is at best 110dB/W/1M, the 117dB is the 1mW terminated tube rating. Quote Link to comment Share on other sites More sharing options...
66hr Posted August 30, 2010 Share Posted August 30, 2010 And to be honest, this was a job. I found out how much my hands shake, how blind I am and how hot the end of a soldering iron is, not once but several times. One last bit of advice, DON'T SOLDIER WHILE WEARING SHORTS! Dan, recovering from the pain.... Very funny, Getting older Maybe? When I was a young fella a remember kneeling on a hot iron, in shorts[:S] Quote Link to comment Share on other sites More sharing options...
dan4510 Posted August 30, 2010 Author Share Posted August 30, 2010 Yeh, I am getting older. Turned 52 this month and have had a lot of health problems during the last 20 years. Its been several years since I tried close work like this and found out I lost a lot of steadyness, fine motor control, and up close detail on my eyes. Only thing that really bothers me about this is the implications for using a handgun for self defense...may have to move up to a pump shotgun to make sure I hit now...lol They say there is nothing louder in the dead of night than a pump shotgun racking in a shell. Oh, well, you live and learn. I got it done anyway and they look quite good, all the solider points are solid and I cant wait till i get the box done and everything wired up and see how it sounds. Dan Quote Link to comment Share on other sites More sharing options...
kcchong Posted September 1, 2010 Share Posted September 1, 2010 Hi Dan, I'm also planning on buying an XM44 kit. Just curious which opamp did you upgrade and where did you get these upgrades? from Marchand? Thanks Quote Link to comment Share on other sites More sharing options...
dan4510 Posted September 1, 2010 Author Share Posted September 1, 2010 I bought the op amps from http://www.digikey.com, part number was OPA2134PA-ND Burr Brown cost about $4 each ************************************** The pots were from http://www.abra-electronics.com part number P2W10K, 2 Watt Linear Taper Potentiometers- 10K Ohms got knobs to fit also from them part number KN-1 I bought the linear taper since that was what marchand recommends. Dan Quote Link to comment Share on other sites More sharing options...
dan4510 Posted November 10, 2010 Author Share Posted November 10, 2010 Latest update on my crossover build. Mocked up how I am gonna place the boards in the box. Box is made of 1/4" thick red oak. Will finish building box, stain it, and put electronics back in wire it up. Hopefully in the next two weeks. Can't wait to complete it and hook it up. Dan Quote Link to comment Share on other sites More sharing options...
dan4510 Posted November 25, 2010 Author Share Posted November 25, 2010 More Progress. Wired the power supply side. Put rca ins and out on back board of box and pots on front part of box. Next step is wire up all the ins and outs to the crossover boards. Dan Quote Link to comment Share on other sites More sharing options...
dan4510 Posted November 25, 2010 Author Share Posted November 25, 2010 more pics Quote Link to comment Share on other sites More sharing options...
dan4510 Posted November 25, 2010 Author Share Posted November 25, 2010 another picture Dan Quote Link to comment Share on other sites More sharing options...
Guest " " Posted November 26, 2010 Share Posted November 26, 2010 Nice wood box. Nice selection for components. The line levels are pretty high, so depending what gets co-located to your. xover, noise might not be a problem. But, if you do pick up noise, and want to stay with a wooden box, line the inside with a continuos length of metal screen like the type used for window screens and ground the screen, power supply, and rca jacks using a star grounding system. use spacers under the circuit boards so the circuit trace does not touch the screening. Quote Link to comment Share on other sites More sharing options...
dan4510 Posted November 27, 2010 Author Share Posted November 27, 2010 More pics. Wiring done except for 110 supply to power up with. I am not the most organized with the wiring, but it goes where its supposed to and is soldered llike it should be. Now I just gotta finish the box. Gonna have a hinged lid so I either have it closed or open to look at. Dan Quote Link to comment Share on other sites More sharing options...
dan4510 Posted November 27, 2010 Author Share Posted November 27, 2010 Box Completed with four sides and stained. Quote Link to comment Share on other sites More sharing options...
dan4510 Posted November 27, 2010 Author Share Posted November 27, 2010 Front of box after stain. Quote Link to comment Share on other sites More sharing options...
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