cjgeraci Posted February 14, 2009 Share Posted February 14, 2009 902s attached. Carl. 1 Quote Link to comment Share on other sites More sharing options...
cjgeraci Posted February 14, 2009 Share Posted February 14, 2009 My "babies" Carl. Quote Link to comment Share on other sites More sharing options...
IB Slammin Posted February 14, 2009 Share Posted February 14, 2009 My "babies" Carl. Without question you have some nice babies there. I would love to listen to them! We are not all that far away from each other, but I can't drive in your city. Like driving in Atlanta to visit JWC. I have been on the road in LA at 5:00, but still SLM and Atlanta are ........... tc Quote Link to comment Share on other sites More sharing options...
lnmnmarty Posted February 15, 2009 Author Share Posted February 15, 2009 Thanks Carl. I appreciate the direct answer. What type of active crossover do you use? Quote Link to comment Share on other sites More sharing options...
Blvdre Posted February 15, 2009 Share Posted February 15, 2009 How did you mount them? All of that blocking is in the way. I thought about getting longer bolts. Did you make a new mounting plate? Could you post photos? Thanks, tc Sorry I can't post photos, I no longer have that particular set-up. I couldn't see a way to make it work with just one mounting plate, because of the size of the driver and mounting hole/ block location, so I went with two sandwiched together (see terrible pic). I removed the original plate and added two larger plates. I counter bored for the various mounting screws, and held the plates together with screws and nuts through the corners. Admittedly a messy affair, so this time around, I'm using a different scheme for the JBL drivers: a couple of P Audio adapters (select p audio and scroll to the bottom). I'm mating the male adapter to the driver, and the female to the horn. A much better solution I think, and easier to implement (pic 2). Quote Link to comment Share on other sites More sharing options...
IB Slammin Posted February 15, 2009 Share Posted February 15, 2009 Perfect. That sketch was exactly what I was looking for.[Y] Many thanks, tc Quote Link to comment Share on other sites More sharing options...
Blvdre Posted February 15, 2009 Share Posted February 15, 2009 Glad I could help. Quote Link to comment Share on other sites More sharing options...
Deang Posted February 19, 2009 Share Posted February 19, 2009 "Actually I crossed them at 400hz first order with Al's Universal Network. No problems at all, sounded fine down there. That was with the lightweight A type diaphragms in them without the loading caps." Hi Shawn, Al's Universal Type A is 1st order low pass, 2nd order bandpass, and 3rd order high pass. I also mentioned my inexperience with filters, because I was wondering if I mucked up the x-over. For a nominal impedance of 8 ohms, I figured a 33uF for a 1st order high pass at 600Hz. Just curious what you were using for attenuation. If you were using an autoformer, and hanging off tap 4 -- the impedance is doubled to 16 ohms. With a 33uF cap, it would have put your crossover at 300Hz. Quote Link to comment Share on other sites More sharing options...
Blvdre Posted February 19, 2009 Share Posted February 19, 2009 "Actually I crossed them at 400hz first order with Al's Universal Network. No problems at all, sounded fine down there. That was with the lightweight A type diaphragms in them without the loading caps." Hi Shawn, Al's Universal Type A is 1st order low pass, 2nd order bandpass, and 3rd order high pass. I also mentioned my inexperience with filters, because I was wondering if I mucked up the x-over. For a nominal impedance of 8 ohms, I figured a 33uF for a 1st order high pass at 600Hz. Just curious what you were using for attenuation. If you were using an autoformer, and hanging off tap 4 -- the impedance is doubled to 16 ohms. With a 33uF cap, it would have put your crossover at 300Hz. Good point Dean. I am aware of the autoformer issue, and that if I were using tap 4, a 16uF cap would be appropriate. I think you're close though....I used an L-pad, but not a variable type. I don't think I paid enough mind to the L-pad's effect on impedance (used resistors that were in the ballpark), and so probably inadvertantly changed the impedance. Maybe that explains the issue I was experiencing. Quote Link to comment Share on other sites More sharing options...
Deang Posted February 19, 2009 Share Posted February 19, 2009 Don't know, it was just a thought. I can't imagine a mistake using resistors that could be so bad as to cause that -- well, unless I was doing the math for you. Personally, I don't think any of the 1" drivers with alloy diaphrams are good candidates for the Klipschorn unless you run them with Al's Extreme Slope Network. Quote Link to comment Share on other sites More sharing options...
IB Slammin Posted February 19, 2009 Share Posted February 19, 2009 OK. You guys convinced me. I will go a different direction.[] tc Quote Link to comment Share on other sites More sharing options...
Deang Posted February 19, 2009 Share Posted February 19, 2009 O.K., here's an Altec plot of the 909, which is similar to the 902 -- we are mainly interested in the low end. The plot was done with the driver on the 511B. Quote Link to comment Share on other sites More sharing options...
sfogg Posted February 19, 2009 Share Posted February 19, 2009 Here is a 902 on a 511B... Quote Link to comment Share on other sites More sharing options...
seti Posted February 19, 2009 Share Posted February 19, 2009 Sfogg, I had just saved that from that thread earlier today. Is that Altec or GP? Quote Link to comment Share on other sites More sharing options...
sfogg Posted February 19, 2009 Share Posted February 19, 2009 Altec with the lighter A type diaphragm in it. Shawn Quote Link to comment Share on other sites More sharing options...
Blvdre Posted February 19, 2009 Share Posted February 19, 2009 Don't know, it was just a thought. I can't imagine a mistake using resistors that could be so bad as to cause that -- well, unless I was doing the math for you. Personally, I don't think any of the 1" drivers with alloy diaphrams are good candidates for the Klipschorn unless you run them with Al's Extreme Slope Network. I used a 2.5 ohm series w/20 parallel (~ -3db), so that seems about right. Still might be the diaphragm alignment issue. We'd make a good team - I can run the numbers, but I've forgotten just about every last trace of electronic theory. I blame SMT technology. "The PCB's bad? I'll have to swap it out." I swapped my recently refurbed pair of 2470's in for my k55's using the k400's and almost stock design A's (tap# 3), just to see how they'd sound. They handled the 400Hz x-over point just fine, sounded clean and well balanced. I wouldn't use them for 2-way design, though. Quote Link to comment Share on other sites More sharing options...
seti Posted February 19, 2009 Share Posted February 19, 2009 Altec with the lighter A type diaphragm in it. Shawn How does it compare to the Great plains version? From the GP 902 doc. Hydropneumatically formed all-metal aluminum dome and tangential compliance driven by a 1.75-inch diameter voice coil of edgewound aluminum ribbon. Quote Link to comment Share on other sites More sharing options...
sfogg Posted February 20, 2009 Share Posted February 20, 2009 Last time I talked to GP (years ago) they were only making the heavier type diaphragms for the 902s. The voice coil on them is larger so it can handle more heat/power. Shawn Quote Link to comment Share on other sites More sharing options...
seti Posted February 20, 2009 Share Posted February 20, 2009 Last time I talked to GP (years ago) they were only making the heavier type diaphragms for the 902s. The voice coil on them is larger so it can handle more heat/power. Shawn Interesting. The GP is my first experience with 902s and I'm a big fan. I'd love to compare with other 902s. Quote Link to comment Share on other sites More sharing options...
lnmnmarty Posted April 29, 2009 Author Share Posted April 29, 2009 Hi All, just thought I would give an update to anyone who is interested,or might want to try this. I picked up a set of 511b's and mounted the 902's on them. I set them on top of the Khorns and unhooked the k55's and hooked up the 902's. Well I have to say it is a definite improvement. Now, of course, the 511 horn is gonna sound better than the 401 anyway but the 902's sounds so much sweeter. Even at high volume. No buzzing, no harshness, just fuller sound. Haven't tried hooking the k55's to the 511's yet (not positive I can) but will try someday and post my impression of that if it is worthwhile. Also wanted to say how much I enjoy this forum. You guys are great! Marty Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.