mikebse2a3 Posted August 2, 2012 Share Posted August 2, 2012 W. C. The only detail I don't see in the picture is the bolt pattern for attaching the Adapter to the driver. You can measure your driver or possibly go by the 1/2" adapter details for that info. I beleive it is 87.3mm diameter pattern. Edit: Just noticed the adapter bolt pattern is shown in the drawing and is 87.5mm Quote Link to comment Share on other sites More sharing options...
Guest " " Posted August 2, 2012 Share Posted August 2, 2012 drilling out an altec adapter won't work? http://www.ebay.com/itm/Altec-33710-1-4-driver-2-horn-throat-adapter-EV-JBL-/350385803973?pt=Vintage_Electronics_R2&hash=item51949f12c5#ht_510wt_1213 Quote Link to comment Share on other sites More sharing options...
ClaudeJ1 Posted August 3, 2012 Share Posted August 3, 2012 Claude, I haven't taken the horns off of the 4002's yet but I am pretty sure that I WILL need an adapter. I will either have to buy them or have them machined. This is going to be a very stupid question: Suppose I re-drill the K 402 flange and bolt the 4002 directly to it. Will not having an adapter to make up the 1/2", make that much difference? I do have a drawing that I can get a 1/2" thick adapter made and there is a machine shop a block from me. Hope that question made sense, as I almost coRnfused myself........ Of course, it would be wonderful, if someone had some adapters just lying around.....Yea....right...!!!!!!!! Why is it that everytime you try to do something....You need to get more STUFF....? W. C. 1.4 to 1.5" throat drivers were evolved by EV with their original "big white whale CD horn" in Don Keele's papers. JBL followed suit with smaller throat/shorter throw in the 2447J drivers with bi-raidal horns.............much better HF extension and dispersion than the 2" drivers. Peavey does the same thing with their XT44 driver and you may be able to purchase their adapter pretty cheap. I will look into it further for you. Better just to buy one than make one at this point. Quote Link to comment Share on other sites More sharing options...
djk Posted August 3, 2012 Share Posted August 3, 2012 To maintain wide dispersion, the taper on the adaptor should match that of the horn. If the entry of the horn has a 90° pattern (no neck) then the adaptor should also have a 90° taper. If you use the TAD adaptor you will limit the dispersion at 10Khz to 50°, 12.8Khz to 39°, 16Khz to 30°. For 90° from 1.5" to 2" the adaptor plate need only be 1/4" thick. The 'stub' inside the driver on older designs has a taper rate of 190hz, to provide good loading for the diaphragm to work against when crossed at 300hz. Modern drivers do not have this 'stub', and have less distortion in the top octave because of it (distortion being a function of the square of the bandwidth in octaves). Ideally we would want the phase-plug of the driver to protrude into the horn throat for the best dispersion and smoothest response. Every time the taper rate from the diaphragm to the mouth of the horn changes it causes reflections back to the diaphragm that cause ripples in the response. A modern pancake type driver with no 'stub' inside the driver. http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=17636&stc=1&d=1156539206 Quote Link to comment Share on other sites More sharing options...
Panacea Engineering Posted August 3, 2012 Author Share Posted August 3, 2012 I'm not understanding about the 90 degree and it's relation to the 1/4 inch plate. I thought everyone said this adapter did not work. It would seen that the sharp angle going from 1.5 to 2 inches, in a 1/4 inch space, would not be anywhere near the taper of the K 402. I've read in several different locations about a seven degree taper for the throat of the adapter, For 1.5 to 2 inch would make the adapter two inches in length. The TAD 4002's are 1.5 inch not 1.4 inch drivers, so I don't think the 1.4 inch adapters will work either. I have been searching for several hours and have not really found too much about the 1.5 to 2 inch adapters. Again, this is a complete learning process for me........ The quest continues....... W. C. Quote Link to comment Share on other sites More sharing options...
djk Posted August 3, 2012 Share Posted August 3, 2012 I need to see a drawing of the throat area of a K402 please. Quote Link to comment Share on other sites More sharing options...
ClaudeJ1 Posted August 3, 2012 Share Posted August 3, 2012 If it were me, I would start with the TAD adapter, since Roy worked out all of the EV Digital Xover settings with those. Narrowing at the top end is normal and the numbers quoted by DJK are not bad. My 2360a JBL horn narrowed after about 8 Khz. and so does the K402. You can't expect a horn that can be modified into a Midbass horn with an 8" driver to also have the dispersion characterisic of a dedicated super tweeter in a 3-way setup. You get better phase coherence in a 2-way with a K402, but ALL of them narrow after 8Khz. Unless you went to do endless R&D, I would stick to the TAD version to get to your goal more quickly. Quote Link to comment Share on other sites More sharing options...
Panacea Engineering Posted August 3, 2012 Author Share Posted August 3, 2012 Claude, It looks like the only way I am going to get the TAD adapters, is to have them made, unless YOU have a set laying around somewhere, not in use.[] Quote Link to comment Share on other sites More sharing options...
Coytee Posted August 3, 2012 Share Posted August 3, 2012 They do come up for sale every now & then. Rare yes...but I've seen them. Another angle would be contact TAD themselves & see if you can order the part? Another angle would be to buy another pair and sell what you have? It's easy when it's your money that I'm spending [] Quote Link to comment Share on other sites More sharing options...
ClaudeJ1 Posted August 3, 2012 Share Posted August 3, 2012 Claude, It looks like the only way I am going to get the TAD adapters, is to have them made, unless YOU have a set laying around somewhere, not in use. Methinks I hear aluminum shavings being made on a Bridgeport as we speak. LOL. Quote Link to comment Share on other sites More sharing options...
djk Posted August 3, 2012 Share Posted August 3, 2012 http://www.martinsoundpro.com/upload/item/4754.pdf BEC can order. Quote Link to comment Share on other sites More sharing options...
Panacea Engineering Posted August 3, 2012 Author Share Posted August 3, 2012 Thanks for the PDF. You can order direct from Martin Sound and they should be on the way here, on Monday. It appears that this adapter uses the seven degree throat. Quote Link to comment Share on other sites More sharing options...
Speakmeister Posted August 3, 2012 Share Posted August 3, 2012 I have a pair of these that work well. http://www.loudspeakersplus.com/product/PC5038/P-AUDIOPC5038/ Quote Link to comment Share on other sites More sharing options...
Panacea Engineering Posted August 3, 2012 Author Share Posted August 3, 2012 It's funny how prices run. They were 32.00 a pair, direct from Martin. Quote Link to comment Share on other sites More sharing options...
ClaudeJ1 Posted August 4, 2012 Share Posted August 4, 2012 It's funny how prices run. They were 32.00 a pair, direct from Martin. Well this is good news. Methinks we will see curves or read some interesting words in about a week!! Quote Link to comment Share on other sites More sharing options...
mikebse2a3 Posted August 4, 2012 Share Posted August 4, 2012 Just to make note of some things for anyone interested. The K402's included angles in the throat region are (Vertical: 50 degrees) and (Horizontal: 80 degrees). The stock TAD adapter's 39mm to 50.8mm by 63.5mm length has an included angle of 10.62 degrees. The custom(rigma) 39mm to 50.8mm by 1/2" length adapter's included angle is 49.84 degrees. The Martin 1.5" to 2" x 2" length adapter calculates out to an included angle of 15.39 degrees. If you look at the TAD TD-4002 's details drawing I posted earlier you will see that they designed their adapter to maintain the same included angle all the way to the phase plug area. I believe this was done so as not to have a shift in angles close to the phase plug. As a matter of fact if you look at the TAD TD-4001 's details drawing and compare that to the TD-4002 you will see for all intents they share the same design in the expansion path from the phase plug to the 2" exit hole of the TD-4001 and TD-4002/with adapter. The reality is compromises are made when drivers like we have currently designed are mated to horn's having different vertical vs horizontal coverage angles. The 1/2" long 49.84 degree adapter was an attempt to see if we at least made the adapter's angle match closer to the K402's vertical angle could we improve on the stock TAD adapter when used on the K402 and by what we tested and I heard I wouldn't recommend the 1/2" adapter. It will be interesting to see how the Martin adapter test (unless an unforseen glitch pops up from the early small angle change it creates) and will probably perform very close to the stock TAD adapter since it has a small angle shift versus the 1/2" adapter we tried. miketn Here is the TAD TD-4001 detail drawing for comparison to the TD-4002 drawing fo those interested. Quote Link to comment Share on other sites More sharing options...
Panacea Engineering Posted August 4, 2012 Author Share Posted August 4, 2012 Mike and Everyone, Thanks for all of the information. I will take very close pictures of the Martin adapters when they arrive. Hopefully this will help the next person out, that acquires the TAD drivers without the adapters for two inch. My friend out in Burbank has received a few more sets of the TADS and he is going to see if there might be some adapters with the new (as in new to him, not actually new) inventory he received. They are sorting through the stuff this weekend. W. C. Quote Link to comment Share on other sites More sharing options...
mikebse2a3 Posted August 4, 2012 Share Posted August 4, 2012 W. C. your welcome. I like threads like this that make me take a deeper look for a better understanding. miketn Quote Link to comment Share on other sites More sharing options...
Panacea Engineering Posted August 4, 2012 Author Share Posted August 4, 2012 Mike, In audio, I don't particularily think there is an absolute right and wrong...Sure there are basic guidlines, but I don't think that any one thing is definate. It all relates to what is right for the Individual and His/Her Ears. Gather as much knowledge as you can and try your best to make Informed decisions...How can you go wrong with that? Quote Link to comment Share on other sites More sharing options...
djk Posted August 4, 2012 Share Posted August 4, 2012 I'll take those off your hands if you don't like them, or don't need than after getting the TAD adaptors. 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.