DizRotus

Semi-Promedia?

Andy- As I type Im listening to American Routes through the drivers below: PIONEER A11EC80-02F 4-1/2" FULL RANGE Paper cone with treated cloth surround. Open back and stamped basket. Perfect for bookshelf type speakers and car stereo installations. * Power handling: 20 watts RMS/30 watts max * Voice coil diameter: 1" * Impedance: 8 ohms * Frequency response: 70-15,000 Hz * Magnet weight: 9.3 oz. * Fs: 70 Hz * SPL: 90 dB 1W/1m * Vas: .31 cu. ft. * Xmax: 1.1mm * Qms: 1.40 * Qes: .47 * Qts: .35 * Net weight: 2 lbs. * Manufacturer model number: A11EC80-02F * Dimensions: Overall Diameter: 4-1/2", Cutout Diameter: 4-1/8", Mounting Depth: 2-3/8", Magnet Diameter: 3-1/8", Magnet Height: 1". The specs suggest that these should work as well in the rear horn as any of the five Im now using. They sound ok so far. On paper they compare to the Fostex FE83 and FE103. Ill try to get my hands on each of the Fostex drivers to test them in the enclosures. I recognize the benefits of smaller drivers for the mid/high frequencies in rear horn enclosures. Nevertheless, if the benefits (read imaging) of the single driver rear horn configuration impress me sufficiently, I might build larger rear horn enclosures and experiment with 8 Fostex and/or AER full range drivers. I have absolutely no intention of resorting to tweeters or subwoofers. As you said, that would be cheating.

---------------- On 6/25/2005 7:53:51 AM boom3 wrote: These appear to be LDL speakers, which appeared a year or so after the 901s came to market. Circa 1971. It was they who ripped off Bose, not vice-versa. High Fidelity tested them and found they had a response curve humped between 200 and 5 KHz and rolled fast at either end.I don't know for sure, but I'd bet Bose sat on them and made them stop making these abortions. ---------------- You might be correct. Visit the link below: http://www.epinions.com/content_4064256132 Everything you want to know about Bose 901 speakers. Based upon the comments (linked article) of the above Bozophile, those speakers don't appear to be LDL. Until proven to the contrary, I continue to believe that they're well done DIY copies of 901s. In any case, I'd bet my Cornwalls that Bose did not copy those speakers. The bidding has ended. Perhaps the seller was shamed into removing those faux Blose.

Andy- I just checked out the specs of the FE83 on the Madisound site. It looks like it would be worth investigating. Thanks for the input.

DrBill- Perhaps the tubes are located where they are for the same reasons the Brits lost the motorcycle industry to the Japanese. The never made an impact in computers because they couldn't figure out a way to make them leak fluids. Oh no! My Lucas monitor just went dark.

That makes sense. I guess that leaves me unphased on these.

Thanks Marvel. I assumed it did something like that, even when I mistakenly thought it moved with the cone. I thought you were going to take a summer hiatus from this Forum.

Oops! I just discovered that the "phasing plug" does not appear to be attached to cone, i.e., it does not add mass to the cone.

Here is the link. RARE VINTAGE PRE BOSE 901 SPEAKERS 50s/60s ALTEC JBL IMHO these are homemade "rip-offs" of Bose 901s. Although apparently well finished they do not appear to be commercially professionally made. Where is the equalizer, without which these would lack the bass and trebel that even the 901s are able to produce when fed >60 watts of power?

The TB 616S has a silver metal "phasing plug." Whats the purpose of such a plug? Intuitively it seems that the added mass would only be detrimental to the ability of the cone to change directions rapidly. I've heard the EV T-35 described as having a phasing plug also. But, after replacing numerous T-35 diaphragms, I know that its plug is part of the metal housing and not the diaphragm, i.e., it would add no mass to the moving diaphragm; not like on the TB 616S.<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />

The 39 cent Pioneer drivers sound very good, worth at least a dollar. The enclosure benefits each of the five drivers used; some more than others, but each sounds much better than in free air. I've just begun to experiment with damping the enclosures. In keeping with the low budget theme of the experiment, I eschewed long fiber wool or even the stuff from Parts Express for bagged genuine Poly-Fil ® (20 oz. for $3.50) from Michaels. The early results are promising. The vocals and piano in a live recording now sound more natural.<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /> Just when I think its sounding real good I switch back to the Cornwalls for a reality check. The Cornwalls are better at the extremes, and they are more efficient. The imaging of the single driver is better, though. I do not have the ability to measure the frequency response. Nevertheless, with the W4-656S, using a bass test CD that goes from >300 Hz down to 10 Hz in 10 Hz steps, there is clearly usable output below 100 Hz. These speakers are well suited to playing jazz combos; the percussion and string bass are tight. The single driver concept is not suited for rock or symphonic music. Although less efficient than Klipsch, Im able to drive them to decent volume levels with the ~11 watts/channel of my Dyna tube amp.

---------------- On 6/21/2005 9:47:28 PM Randy Taylor wrote: " ... he really beleived that all 12ax7's sounded the same, no matter if it was telefunken, RCA, or Mullard they all sounded the same, and that went for any type of tubes and caps too. The only thing I could figure was he didn't listen to any Hi-end audio in his life time or he didn't have good hearing, maybe all he heard in tube audio were the old five tube AM table Radios. "---------------- Or, possibly, he was right.

That's good news. Enjoy your receiver.

---------------- On 5/29/2005 7:37:02 AM filmboydoug wrote: Unfortunately, these are not the most suitable drivers for a rear loaded horn enclosure. I investigated a similar project a while back and learned that for a back loaded horn enclosure you want to stick with a driver with a QTS of about .2 - .3 or so. The TB's are in the .5 area and the pioneer is .76. The Fostex that enclosure is intended for is .36. ---------------- It was understood from the get go that these are not optimal drivers. The Qts (whatever that stands for, I welcome an education on this) of the W4-656S is 0.35 (see attached pdf). On paper it appears to be the best of this bunch. After a short amount of listening, the W4-656S seems to be the best of the bunch. All of the drivers benefit tremendously from the enclosure. The bass is abundant within their limitations. Although the Fostex enclosure plans do not call for it, I'm going to experiment with stufffing the early part of the horn with wool or Dacron. Listening to the male voices of radio announcers indicates that there is too much midrange coming from the rear of the cones. Perhaps stuffing will filter the highs and mids while allowing the lower frquencies to pass. It's hard to imagine that the Fostex FE 103E at ~$32.00 can sound significantly better than the TB W4-656S which cost ~$18.00 when I received it as a gift (it's now ~$23.00 from Parts Express). I still intend to try the Fostex units some day to satisfy my curiosity.

This project, including photos, has been updated in Technical.

Tang Band and rear horn apart

It only took a year but I finally got the enclosures operational. They exceed my expectations. The neighbors wanted to hear them after watching them under construction. They were amazed that the sound was coming from the new smaller speakers rather than the Klipsch Cornwalls. In the attached photo, extra drivers and motor boards are resting on top of the speaker. I decided to attach the motor boards with wing nuts to permit relatively quick changes. A rubber gasket seals the driver to the motor board and another rubber gasket seals the motor board to the enclosure. The immediate improvement in the sound as you put the motor board in position while the driver is playing is amazing. The sound goes from thin with no bass to full with abundant bass. The most surprising part is that the change takes place as soon as the motor board is near the anchoring bolts, and only improves marginally as the wing nuts are tightened. All three of the Tang Band drivers sound very good. The 616S and 654S sound similar to each other. The 656S sounds different; its too early to say which sounds better. Listening had to be suspended to watch the Detroit Pistons in game 5. Tomorrow I will attach the two Pioneer drivers to motor boards. Im eager to hear them, especially the 39 cent driver. Eventually the enclosures will be cleaned up and painted black. It was always my intention to make experimental cabinets rather than furniture.

---------------- On 6/18/2005 9:50:23 PM boomer9911 wrote: is this related to the MJ trial by chance, buy you a slurpee if you share. ---------------- Jacko rubbed a lot of people the wrong way, but to the best of my knowledge he has no connection to Tyco or Dynaco. MJ a tubeophile? Probably. MJ an audiophile? Unlikely.

Cool! Thanks Dean. Years ago I spent an afternoon at the patent office in Crystal City (D.C.). It was an interesting experience. The thing that impressed me the most was the number of items that appeared to be functionally identical, yet each received a patent.<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /> The lesson I took away is the value of a competent, experienced and honest patent attorney. The foregoing should be able to get a patent issued that makes infringement difficult, while simultaneously avoids challenges from other patent holders. The Wright brothers spent years in patent litigation. They had the right stuff but their patent attorney probably did not.

When I considered these in the 70s before buying the SKs, they both used the same Atlas midrange compression driver. After the failed EV licensing experiment, this was as close as Klipsch came to offering a kit. For minimum outlay you got a bass bin, the horns, drivers and Xover. With those, you could duplicate the fanciest Khorns or do something custom, but, some assembly required.

---------------- On 6/18/2005 8:04:39 AM colterphoto1 wrote: "the veneer sure is plain (nasty)" Michael ---------------- Veneer? We don't need no stinkin' veneer. Michael, they have no veneer. That's raw plywood. This style was used behind movie screens in small theaters or by DIY types who supplied their own veneer or built them into cabinets, e.g., the white Khorns (which are not strictly this model as they have full, albeit raw plywood enclosure; they have tops and sides) that you referred to. I considered this product before I bought four Speakerlab SKhorns to use in a mobile DJ business. They were slightly less than twice the cost of the SKs.

I agree with most of what is in here, e.g., wire is wire; electrons flow based on resistance, ignorant of whether the properly sized conduit is a coat hanger or Monster Cable. Remember, many, if not most, quality amplifiers use sold core wiring inside.<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /> Nevertheless, I still prefer tube equipment for the reasons stated in the two posts in the thread started by DrBill<1><1> and voiced elsewhere in the Forum. Ive no doubt that solid state amplifiers exist that would be indistinguishable from my favorite tube amp in a blind compoarison. Nevertheless, such and amp could not be designed, built or serviced by me. OTOH tube equipment lends itself to DIY. Another possible explanation of the resurgence of tube gear is the resurgence in the recognition of the merits of efficient (read horn) speakers. The solid state topology permits large amounts of inexpensive power needed to drive inefficient speakers. Efficient horn speakers thrive on well designed amplifiers that focus on parameters other than raw power. <2><1> NO MORE SS GEAR ON MY BENCH! Posted <?xml:namespace prefix = st1 ns = "urn:schemas-microsoft-com:office:smarttags" /><?xml:namespace prefix = u1 />6/5/2005 I also keep an H/K 430 receiver to use when my tube gear is undergoing repair and/or upgrades. But I agree, other than replacing fuses or possibly pots, I would not attempt to repair the H/K 430. Sadly, it would be easier and less expensive to buy another one. Posted 6/7/2005 Like you, I like to work on and use tube gear, but that doesnt mean that I dont recognize the merits and limitations of both SS and tube equipment. Many of the new versus old issues are the same for cars as they are for audio. One could open the hood of a 60s Chevy and see the ground. Things were easy to get to, which was good, because they often needed getting to. Open the hood on a current Japanese car and you cant identify, or get to, anything serviceable, which is OK, because they rarely need service. The car in my avatar is a Rotus 8, which is like a Lotus 7 on steroids. It has a carbureted Buick/Rover 3.5 liter aluminum V8. It was easy to work on, which was handy because it needed to be worked on regularly. Every six weeks I had to pull the motor. After selling the Rotus, on an impulse I bought a 97 Miata with every intention of putting a Buick/Rover 3.5 liter aluminum V8 into it also. The engine transplant never occurred. I quickly came to the realization that there is something to be said for a car that starts every time and does not demand constant maintenance. Each car will get you from A to B. Each has its strengths and weaknesses. Neither is right or wrong; theyre different. The same is true of audio gear. It all plays music. There is no universally perfect path to high fidelity. While I prefer to tinker with tube gear and carbureted cars, Im not prevented from using, but not working on SS gear or fuel injected cars. http://forums.klipsch.com/idealbb/editor.asp?sessionID=&catD=19&forumID=66&topicID=67096&action=&quote=&file=&type=reply&mode=edit&pageNo=1&replyID=579074#_ftnref2' name=_ftn2>

Can't feel sorry for the Tyco defendants and their guilty verdicts. Tyco's purchase of Dynaco killed one of the few companies that catered to knowledgeable audio enthusiasts. Dynaco, as we learned to know and love it, might have already been on life support, but Tyco then pulled the plug.<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /> The fact that David Hafler was unable to carry on Dynacos mission suggests that Dyna was dead with or without Tyco. Dynaco exists now in name only.

Not to my knowledge. The seller has concerns about the sale being completed. The high bidder is in Florida so the seller is waiting to see the $ and to hear how the buyer plants to arrange local pickup. In the two times the speakers have been listed on eBay, the seller has been contacted by numerous scam artists from all over the world. The big ticket items seem to invite fraud. The seller has promised to let me know if the sale falls through.

Thank you.