john5 Posted September 27, 2017 Report Share Posted September 27, 2017 I have an original Karlson X-15 cabinet that years ago I bought an Electro Voice 15TRX and installed in, but didn't have the crossover for until recently (an x36). I have tried it both with a 50s-era mono Harmon Kardon tube amp I have (running 16 ohms) and with one channel of a Marantz 2265B amp, running I presume 8 ohms and in both cases I have almost no bottom end to speak of running flat. If I engage the loudness control on the Marantz (which I don't generally like to do) then I have a reasonable bass response, but nothing special and regardless I'm thinking I shouldn't have to do this with this driver in this cabinet. Not sure where to really start - any suggestions? John Link to comment Share on other sites More sharing options...
JKent Posted September 29, 2017 Report Share Posted September 29, 2017 John, I'd be surprised if there's much help here but you never know. I did a little google search and that coaxial driver apparently has a built-in potentiometer (?). Cleaning the pot with de-oxit may help. I'm just guessing here. I'm also wondering about the xo. I was looking at this site and they say the original xo is potted with black tar and not rebuildable, so they build new ones http://www.critesspeakers.com/electro-voice-crossovers.html If you google "15TRX" and also "x36 crossover" you may find some helpful leads. Good luck and let us know how you make out. Nice LP! Original 1954 mono? -Kent PS: Those repro xo's are pricey. Used ones show up on ebay. Found this schematic and looks like it would be very easy to reproduce. I'm assuming "M.F." is mF or uF (microfarad) and M.H.is mH or milliHenry but maybe someone more knowledgable can decipher these. You'd have to use a 2.7uF or parallel some caps to get 2.84uF, and unwind some inductors inductors to get 0.727mH. Link to comment Share on other sites More sharing options...
Pete B Posted October 1, 2017 Report Share Posted October 1, 2017 The enclosure is a folded transmission line with and odd tapered port, and there was an article about them in Popular Electronics back in the 1960s and 70s. The inventor paid a math guy to do the analysis and I scanned it for a few people on the net, I believe that it is out there somewhere: http://www.cameng.com/pdf/the_k-coupler_a_new_acoustical-impedance_transformer.pdf I would try the box with a modern woofer for bass only, with a tweeter sitting on top and see what you think. If you Google Karlson K-coupler you will find many pages about them on DIYaudio and many other sites. Link to comment Share on other sites More sharing options...
Analogman Posted January 11, 2018 Report Share Posted January 11, 2018 I love EV, but not a lot of bass out of those unless you put them in a huge box, like 20 cubic feet and they can go subsonic (not kidding) Otherwise, not so much in the bass department from the elder EV co-axes without some sincere box tuning That box was designed by the way with the Stephens 206 in mind although the Altec 604 works VERY well too The best match I ever heard (and briefly owned) was with a Stephens 206 AXA I got out of that part of the hobby, not because I didn't love it, they sound GORGEOUS done right, but for the fact that glue kept failing me and I couldn't get any proper bits and parts to keep things up and running Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.