bigdnfay Posted March 12, 2005 Share Posted March 12, 2005 Hi All, I hate to beat a dead horse, but I am having a little difficulty locating the right woofer for my Jubilee build. I have talked to a few engineers who said that T/S parameters are not as critical as I thought. To me it appears that at least a few are. For one, the Fs. the parameters listed in the AES paper call for a 19 Hz Fs. Why so low if the horn is only designed to go down to 38 Hz? Another is the Bl, the higher the Bl the driver operates with more authority. I am trying to keep the Re(6 ohm) and Le (1.0 mhy)close to Al's Es700 requirements. I hope this makes sence to everyone, I've been at this for 2 weeks and I don't know if I'm coming or going. I guess the big question is, What are the most important things I should be looking for? Heeelllppp Please, Big D Quote Link to comment Share on other sites More sharing options...
Marvel Posted March 12, 2005 Share Posted March 12, 2005 Are you using a single 15, two 15s, two 12s" If you are using a single 15, D-MAN posted the Eminence CB15 as a candidate. Re of 6.03 Le is higher though at 1.51mH Marvel Quote Link to comment Share on other sites More sharing options...
bigdnfay Posted March 12, 2005 Author Share Posted March 12, 2005 2-12's Quote Link to comment Share on other sites More sharing options...
Marvel Posted March 12, 2005 Share Posted March 12, 2005 That changes things. I help look too. Quote Link to comment Share on other sites More sharing options...
bigdnfay Posted March 12, 2005 Author Share Posted March 12, 2005 I've been looking at the Eminence Kappa-pro 12. Quote Link to comment Share on other sites More sharing options...
bigdnfay Posted March 12, 2005 Author Share Posted March 12, 2005 http://www.ossaudio.com/hornbackgrounder.htm I read this article and it states a smaller coil is a good thing..faster transients,etc. Quote Link to comment Share on other sites More sharing options...
Marvel Posted March 12, 2005 Share Posted March 12, 2005 Had you looked at the Pioneer drivers at PartsExpress? One of those was mentioned as suitable, or even the ones from Klipsch, used in their Pro Jubilee? Marvel Quote Link to comment Share on other sites More sharing options...
bigdnfay Posted March 12, 2005 Author Share Posted March 12, 2005 I've looked at the pioneer in parts express and their chart says it's not suitable for sealed enclosuers. I talked to klipsch parts dept. He looked up the pro Jubilee and all that came up was the K-31-E. this is also the replacement woofer for the KLF-30. So I ordered one. It's a poly-carb cone with a foam surround. It's not really designed for flush face mount. It's a drop in from the front. There's a hard plastic ring just outside the surround. Not goot for making a good seal. Big D Quote Link to comment Share on other sites More sharing options...
greg928gts Posted March 12, 2005 Share Posted March 12, 2005 I think the K-31-E is your best bet. What about using a double motorboard like the old Khorn. Mount a square wood piece to the woofer that leaves enough space for the woofer to work, and then mount that to the inside of the cabinet. They mount those woofers in the Pro Jubilee somehow. Just do it already! I want to see how this works out for you. Greg Quote Link to comment Share on other sites More sharing options...
djk Posted March 13, 2005 Share Posted March 13, 2005 "I've looked at the pioneer in parts express and their chart says it's not suitable for sealed enclosuers." So what? The Jubilee is a horn. The reason it won't work well in a sealed box is the Qts is too low, exactly the same 'defect' that will make it work well in a horn. It has the same mass corner as the JAES specified driver, and the same reactance annulment net volume and frequency. I don't like the cheezy plastic cone and foam surround either, but for $50 its hard to beat (seems to me the KLF woofers are also 'cheezy plastic cone' and a lot more $). Quote Link to comment Share on other sites More sharing options...
WMcD Posted March 13, 2005 Share Posted March 13, 2005 If you look at the article, the footprint of the Jubilee is the same as the K-Horn. They must have been aiming at that. It is the combination of the driver suspension and the rear box which sets overall spring of the system. If you have a very floppy driver, not very spring like, then you can use a smaller rear box (which acts as a stiffer spring). Size being an issue. When you have a less springy driver, the Fs (which is the driver alone) is lower. I've just explained things a bit backwards. Look at the Jubilee article, you'll see that the overall resonant frequency is much higher than Fs. The relatively small rear chamber does that. You should look at the paper by Don Keele which I posted in technical questions (search "article") about design with T-S parameters. The Jubilee article referes to it and uses some equations from it. The calculated throat area is of some importance. One that they don't seem to be concerned with is the projected high freq roll over of the driver. I expect that beaming of high frequencies is taking care of that. Gil Quote Link to comment Share on other sites More sharing options...
tzehbe Posted March 15, 2005 Share Posted March 15, 2005 Hi Big D, Perhaps you find some hints in an article of Dr. Bruce Edgar which you can find in the download section of www.volvotreter.de. You?ll find several jpg of the "Showhorn" article where BE describes his speaker selection process during horn design. I believe the target will be finding the speaker parameters matching throat area, and backchamber volume, which are given in your design. Additional hints may be given PWKs article from 1941 "A corner Horn of small dimensions" where he showed formulars for calculation of the backchamber volume for throat reactance anulling at the lower horn coutoff. Btw, my DIY K-Horns are ready since about 10 months, but I didn?t find the time to scan the pics I made yet and post them. Thanks again for your help ... Thomas Quote Link to comment Share on other sites More sharing options...
D-MAN Posted March 15, 2005 Share Posted March 15, 2005 Perhaps a look at some 12" BASS GUITAR drivers would be in order. However, AVOID electric guitar drivers, they are too limited in fc. Also, any 12" driver used for electric PIANO or ORGAN is a potential candidate as that instrument has an appropriatedly wide frequency range. I would think that the inherent "softness" or "sloppiness" of a foam-type surround should be avoided. It will tend to have a muddy upper-freq response, IMO, and it is ONLY my opinion, so take it with a grain of salt. The fc is paramount, followed by Qts, followed by sensitivity rating. Basically, that is it. The sensitivity rating should be around 96db at 1w/1m (same as a Khorn), I would guess, since you have 2 in each cabinet, the overall sensitivity goes up to the 108db (?) that the Jubilee is rated. Like I mentioned before, the Jubilee drivers are a pain, and are going to be costly - you haven't even got to the upper frequency section yet! Why doesn't anyone EVER listen to me?! DM Quote Link to comment Share on other sites More sharing options...
D-MAN Posted March 15, 2005 Share Posted March 15, 2005 Has anyone considered the 12" driver used in a Heresy for a horn application? This is just a blue-sky guess. I know PWK loved to use the same driver for multiple applications, although he never did a 12" horn... Just a thought. DM Quote Link to comment Share on other sites More sharing options...
Marvel Posted March 15, 2005 Share Posted March 15, 2005 What is the surround made of on the Pioneer? A lot of the new speakers use the rubber srrounds, and they aren't a foam. At least not in the same as the older speakers had. A lot of the subwoofer drivers use the butyl rubber surround. I am still a bit partial to the pleated cloth. They seem to hold up very well. Marvel Quote Link to comment Share on other sites More sharing options...
D-MAN Posted March 15, 2005 Share Posted March 15, 2005 ---------------- On 3/15/2005 1:07:21 PM D-MAN wrote: I know PWK loved to use the same driver for multiple applications, although he never did a 12" horn... src='http://forums.klipsch.com/idealbb/images/smilies/2.gif'] ---------------- Until the Jubilee! How dumb can I get?! Also the original patent Khorn was a 12" driver, but since that was '46, you can't use those (and they were field-coils, as well). DM Quote Link to comment Share on other sites More sharing options...
bigdnfay Posted March 18, 2005 Author Share Posted March 18, 2005 Hi All, Ordered the pioneer woofers from parts express. Recieved them today. They are not as cheesy as I first thought. Even though the surrounds are foam they are surprisingly stiff. I am confident they will do well. Another problem solved. Big D Quote Link to comment Share on other sites More sharing options...
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