jwc Posted October 20, 2006 Author Share Posted October 20, 2006 SpeakrF and Dana and Who would be better than I to predect the response of a driver in a horn loaded application. I don't understand it as well as I do a bass reflex application. The pioneer drivers are not the "quality" that the kappa pros are. When starting this project, I scanned this forum for all the jub material I could find and the Pioneer drivers kept coming up as a mentioned option. I therefore had to buy them to answer some questions. The Kappa drivers are massive and weigh more than a K33. The Pioneer drivers are very light. It was a real pain to squeeze those kappas in the enclosure. Here is the T/S of the JAES : Quote Link to comment Share on other sites More sharing options...
jwc Posted October 20, 2006 Author Share Posted October 20, 2006 Here is the Pioneer http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=290-118 Here is the Kappa pro http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=290-424 Quote Link to comment Share on other sites More sharing options...
Deang Posted October 20, 2006 Share Posted October 20, 2006 ! Quote Link to comment Share on other sites More sharing options...
BEC Posted October 20, 2006 Share Posted October 20, 2006 jc, I wonder how some K-22s might work in the Jub bass bin. Bob Quote Link to comment Share on other sites More sharing options...
jwc Posted October 20, 2006 Author Share Posted October 20, 2006 Bob...what is the T/S of K-22? The newest version if multiple versions. Quote Link to comment Share on other sites More sharing options...
BEC Posted October 20, 2006 Share Posted October 20, 2006 jc, I don't know the T/S for the K-22. Have been meaning to test some of them. I think someone has posted the T/S for the K-22 before, but I don't know where those numbers came from. Bob Quote Link to comment Share on other sites More sharing options...
Deang Posted October 20, 2006 Share Posted October 20, 2006 Forget the K-22, it's not even close. If it doesn't fit within the following framework I wouldn't waste time and money trying it (if your goal is to get it to sound like a Jubilee bottom). Quote Link to comment Share on other sites More sharing options...
Deang Posted October 20, 2006 Share Posted October 20, 2006 Posted by Trey at some point. Quote Link to comment Share on other sites More sharing options...
mas Posted October 20, 2006 Share Posted October 20, 2006 Just a suggestion that can help when taking the measurements. Lay the mic down on the floor in the listening position. You will effectively minimize the early reflection off the floor and minimize some of the superposition imposed comb filtering in the measurement due to the combined direct signal and the delayed longer path reflection off the floor. The mic will act as a cheap pseudo PZM - a technique effectively pioneered by Don Keele.. Quote Link to comment Share on other sites More sharing options...
jwc Posted October 20, 2006 Author Share Posted October 20, 2006 Mas. Yes that is a good suggestion. I think I have done that before. Dean...I forgot...I have that same info. If anything on there would be remotely close...it would be the K-24-K. The Pioneer is the next choice. Quote Link to comment Share on other sites More sharing options...
D-MAN Posted October 20, 2006 Share Posted October 20, 2006 JC, the Kappa Pro's have the low Qts required to go lower in a well designed horn - and I think the Jub would qualify on that account. At first, I though you must be missing something on the setup, i.e., wiring, air leak, etc. But in putting together your reports and checking into the details, I think I might know what's going on. You can go lower down to the Fs of those drivers and below. I have been thinking the one thing you should be getting is "punch" and maybe less bass, indicating that there is not enough available Vb for the drivers. But that is not the case, is it? The reactance of the drivers and the horn needs to cancel each other out and right now, the horn is doing all of the reacting... I think the Jub Vb is oversized for those drivers. You didn't do the math on them, did you? Well, neither did I. If in an oversized Vb, those should sound "floppy" and "loose". Is that the sound? the graphs don't show that. As a matter of fact, they look pretty good. The Kappas theoretically anull with 25 liters per driver, the Jubilee Vb being 37 per, not including the displacement of the drivers themselves. This accounts for lack of punch? These are not annulled as currently configured, of course. To check, put in a couple of (sealed) gallon jugs of water (a gallon is 231 cu. in. or 1 gallon=3.79 liters) to add some displacement and reduce the volume of the back chamber. Water is incompressable, and therefore is a cheap and easy testing method, as long as you don't leak. Replace when you get the actual volume needed. Many ways to do it. A couple of cut-to-form-and-size closed-cell styrofoam or a fire-retardant substitute will work fine, and be completely and easily reversable. I think they call it "structural foam". For adding volume, I use fiberglass, but then I'm cheap. Long-strand natural wool is considered the most sound absorptive. You'll have to decide by ear (or RTA) how much to use. Too much and you'll stifle the top-end. Not enough and no bass. The drawback is that when properly annulled, the response below 38Hz (the horn Fc) is going to fall off at -18db rather than the normal -12db or so. Also, try it WITHOUT the crossover on the drivers - that will let you know exactly what the effect of the crossover is having. It will not hurt the drivers one iota. They are mass-limited in frequency as well as being limited by the horn. However, there is absolutely nothing wrong with your Jub build, judging by the pics. Do not be disuaded by naysayers, those drivers will outperform all comers if properly set up, and that really isn't hard to do. It's simply "tuning". DM Quote Link to comment Share on other sites More sharing options...
jwc Posted October 20, 2006 Author Share Posted October 20, 2006 Dana. I will confess. I didn't calculate the Vb for those drivers. Mighty lazy of me considering it shows exactly how it was done in the article. Honestly, whatever the result was...I would have purchased them anyway. The calculation of the throat size for that driver is different than what the paper calls for too. I see no reason why I can't just RTA with me adding trash to the inside chamber. I will RTA the bass bin w/o the filter tonight if I get home in time. I can then just unscrew the top and stick something in there. What is wrong with quilt or cotton blanket? If it fell of -18dB at 38Hz, I would be please as just to get to a decent SPL at 38Hz. There is no floppy sound at all. There is clean, solid sound. It is lacking the punch I want. I had mentioned before that 80-200Hz area before I RTA'ed the thing. It ended up being weak in that area. I'm not disuaded at all on any driver necessarily. As you can see I was ready to experiment big time. In regards to that, IF ANYONE HAS A SOLID SUGGESTION ON TRYING ANOTHER DRIVER, I MAY DO IT. Just post the idea here. You may need to be prepared to defend your suggestion. This isn't being cocky. I really am happy with my dbb's and feel no reason to rush this. I am enjoying this. If I get them to be more pleasing than the dbb's, that is what I will keep and build another. If not, I will start it in a different way in which I may bug you with later (my mind has come up with several alternatives). Quote Link to comment Share on other sites More sharing options...
D-MAN Posted October 20, 2006 Share Posted October 20, 2006 I think that you have to reduce the back chamber volume, not add to it, so you will need a non-absorptive material. That's what the numbers say, HOWEVER... once in a horn under compression, there is alot of unforseen variables that come into play. I wouldn't worry about the throat size per se. I would normally add volume to the back chamber to lower the Fs of the drivers as you suggest. Yes, by all means experiment, a quilt/blanket is convienient idea and would certainly tell you whether to go in that direction or not. Also try it without a crossover, and let the drivers rolloff naturally on the top end... I have a slight hunch that the crossover point is somewhat questionable and may actually be too low. Could it be that 12" drivers just don't have the "poop" to compare to 15's? That has always been my opinion, anyway. DM Quote Link to comment Share on other sites More sharing options...
jwc Posted October 20, 2006 Author Share Posted October 20, 2006 I will try those things. Dana, there is no doubt that the Real Jubilee has the Punch I'm looking for....12" or not. A dual 15" would be great but lets chronicle that later. Most may not like my description of the real Jubilee's sound but I DON"T think it sounds like a La Scala or a Belle. I don't think it sounds like a Khorn either but I need more exposure to the Khorn in different rooms to be solid on that opinion. I'm telling ya...there is a "Boom" to the sound. I'll know that sound if I get mine right. jc Quote Link to comment Share on other sites More sharing options...
D-MAN Posted October 20, 2006 Share Posted October 20, 2006 Weren't the stock Jubilees you heard heavily EQ'd? DM Quote Link to comment Share on other sites More sharing options...
jwc Posted October 20, 2006 Author Share Posted October 20, 2006 Very good question. I got to hear them one month ago at Coytee's house w/o EQ. He had an active XO with Roy Delgado's recommended settings. Now whether the active XO can throw some EQ in there or not....I don't know. I heard one at Hope this summer on a passive network. I don't believe it was EQ'ed. They sounded the same to me. I had to hear them in two places to be a believer. The sound is reproduceable in the home. I am mainly referring to the Bass bin. I'm done with my last case. Unless I get paged....I get to go home. Possible more testing on the rise. Quote Link to comment Share on other sites More sharing options...
mikebse2a3 Posted October 20, 2006 Share Posted October 20, 2006 Very good question. I got to hear them one month ago at Coytee's house w/o EQ. He had an active XO with Roy Delgado's recommended settings. Now whether the active XO can throw some EQ in there or not....I don't know. I heard one at Hope this summer on a passive network. I don't believe it was EQ'ed. They sounded the same to me. I had to hear them in two places to be a believer. The sound is reproduceable in the home. I am mainly referring to the Bass bin. I'm done with my last case. Unless I get paged....I get to go home. Possible more testing on the rise. Hi jc I've really enjoyed following your project! Great Work! As far as the EQ used on the Jubilee KPT-KHJ-LF section there is a very small amount (-3db) of PEQ applied at 180Hz and 300Hz with the EV DX38 unit. It basically just refines and tightens up the +/- Frequency Response of the Jubilee LF Section. I will say if your not getting the Power/Punch/Tightness that the Jubilee's have the ability to deliver then something probably isn't optimized yet. I might be wrong(haven't done any calculations) but I believe what Dana suggested as far as trying to Optimize the Back Chamber Volume for the particular Drivers you are using or trying the other drivers as a good place to experiment first. As I'm sure you know it's really about maximizing the match between the drivers parameters and particular horn design thats important of which one good example is the K33 and Klipschorn. mike tn[] Quote Link to comment Share on other sites More sharing options...
jwc Posted October 20, 2006 Author Share Posted October 20, 2006 raw bin Quote Link to comment Share on other sites More sharing options...
jwc Posted October 20, 2006 Author Share Posted October 20, 2006 raw bin with large pillow in chamber with plastic covering around it. Quote Link to comment Share on other sites More sharing options...
jwc Posted October 20, 2006 Author Share Posted October 20, 2006 As you can see, the bass bin is very good out to 700Hz. The filling only made changes between 20-30HZ. Quote Link to comment Share on other sites More sharing options...
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