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Author Topic: Refurbishing Altec Voice of the Theater Speakers? David Stambaugh Film God Posts: 4021 From: Eugene, Oregon Registered: Jan 2002 posted 12-12-2002 09:12 PM                        (or is it "...Theatre"?) Found this article that explains in detail how older Altec Voice of the Theater speakers can be "renovated" to perform as well as any modern speakers, at less cost than replacing them with new. The article is aimed at theater owners. I have no idea how feasible this really is, but these speakers have a lot of die-hard fans, so maybe this is of interest to someone. Altec VOT Renovation (PDF file) Same web site has lots of Misc Altec Info & Links  |  IP: Logged Ken Layton Phenomenal Film Handler Posts: 1452 From: Olympia, Wash. USA Registered: Sep 1999 posted 12-12-2002 09:21 PM                     Nice story! I've always enjoyed Voice of the Theater speakers.  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 12-13-2002 08:29 AM                     He harps a bit much on the Alnico loosing its magnatism. While that certainly can and does happen...it isn't as previlent or as severe as the author claims. I've been turning Altec VOTs back into theatres for years. In my opinion, they were indeed the best this industry has ever offered. The 288/299 series drivers are simply the best compression drivers ever made. The 515 series drivers are the best combination horn/reflex drivers. The Mantaray horns had to be designed with devine intervention. To say they are the best is not good enough...they are damn near perfect. If you look at a "modern" 3-way system...particularly the EAW stuff and then look at a picture of an A-5 side-by-side...the similarity is uncanny. Right down to the asymetrical horn flare (the A-5's horn points down...just like all the modern 3-way crap). Some bad advice given in the article was to recone any 515 frame to a 515-G series...the G series spacing is significantly different...a G series cone kit, will fit, but will be misaligned. A 515B should use the 515B,C,E cone kit (aka R515). I don't know what the claim of the "straight 16-Ohm voice coil) is. Now if your reconer has access to the G series cone kit in part form (the voice coil separate from the spider) and has the proper alignment fixtures, a successful conversion to a G type driver can be performed. Older non-suffixed 515s can not take the G series kit...the air gap is too small and the flux isn't right. There is nothing particularly wrong with revamping the older 288s with the 299 diaphragm, despite the claims of the article. The later 288s and the 299 have a "tangerine" phase plug that uses radial slits as opposed to the more commong concentric slits...the results are superior HF response. Your older 288 will still sound like a 288. The extreme HF response isn't too critical in a theatre situation with a 9KHz filter between the audience and the speaker (aka THE SCREEN). You should still have no problem going out to 16KHz with any 288. For what its worth, I still recone Altec driver and stock many of the diaphragms and can even get you new drivers! Steve  |  IP: Logged David Stambaugh Film God Posts: 4021 From: Eugene, Oregon Registered: Jan 2002 posted 12-13-2002 10:51 AM                        Steve, I knew you had an interest in Altec stuff so I hoped you would have something to add. I have an uncle who was a QA engineer for Altec-Lansing back in the late 60s and early 70s. He worked at their main plant, which I believe was in Anaheim. He was very proud of Altec pro products. He was a bachelor at that time and lived in a small apartment, and he had a pair of "large" VOT speakers in his living room. When he got married he had to get rid of them due to the wife factor...  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 12-13-2002 01:32 PM                     I don't know when Altec made the move from Anaheim to Oklahoma City. Hey, what can I say...Altec still is the best...all the other are imitators! Steve  |  IP: Logged Frank Angel Film God Posts: 5305 From: Brooklyn NY USA Registered: Dec 1999 posted 12-13-2002 08:11 PM                        So what's the connection between JBL and Altec-Lansing? Was JBL formed after Altec? Are the speakers designed by JBL based on Lansing's design when he was with Altec? Do the two coexist? We incorporated old, existing Altec Voice of the Theatre dual bins with Mantaray segmented cell horns for our center channel but upgraded to JBLs everywhere else. Frank  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 12-13-2002 08:27 PM                     James B Lansing was the one and the same with Altec and JBL...he was fired from both companies and committed suicide. Altec came first and was an outgrowth of ERPI. JBL is living with, to this day, the fact that James B. changed how he designed his drivers when forming JBL. Altec had an outward cone motion when a positive voltage was applied to the "+" terminal. JBL drivers were just the opposite. JBL is slowly switching all of that though. You will find that the legacy drivers like the 2226, wich replaced the 2225, which replaced the 222x...are, to this day, all positive voltage on red causes the cone to pull in. Same with the HF drivers like the 2446, which repaced the 2445, which replaced the 244x...positive on red causes the diaphragm to draw air into the throat. New drivers that don't directly replace any previous driver...like the 2242 (as used the 4645C subwoofer) are positive on red causes and outward cone motion. So if you have a system with JBL 4675Cs for stage speakers and 4645C subwoofers and 8330A surrounds...the stage speakers will be out of phase with the subs and surrounds if everything is wired red to red and black to black. So in answer to your question, JBL and Altec most certainly did co-exist. JBL has had similar speakers to Altec though they were never the same. Altec VOT speakers always had a front vented driver, I don't think JBL ever did (note the screen on the dust dome of a 515 for the air to escape). JBL's answer to the A-4 was the 4676. The JBL answer to the A-5 was the 4674 and the JBL answer to A-7 was the 4672. JBL's double-15 horn loaded speakers were always horizontal horns (like with the Altec 211 cabinet...the A-4 used the 210 cabinet). Steve  |  IP: Logged David Stambaugh Film God Posts: 4021 From: Eugene, Oregon Registered: Jan 2002 posted 12-13-2002 09:18 PM                        That uncle I mentioned who worked for Altec told me that Altec HATED JBL & JBL products. One of his responsibilities was to check out every new JBL pro speaker that came out and he said they were almost always inferior to Altec's. Since he worked for Altec, he wasn't exactly unbiased, but he really believed in Altec's products. (Keep in mind this is ~30 years ago.)  |  IP: Logged Frank Angel Film God Posts: 5305 From: Brooklyn NY USA Registered: Dec 1999 posted 12-15-2002 06:36 AM                        Yikes, non-standardized speaker polarity -- that's really scary. I better go back and check my Altecs and JBLs -- I may have drivers pulling in opposite directions! Frank  |  IP: Logged William Hooper Phenomenal Film Handler Posts: 1879 From: Mobile, AL USA Registered: Jun 99 posted 12-20-2002 06:46 AM                        I miss the Simplex W at the theatre I departed when the crew was re-hired with underpaid Mars Attacks aliens. It had a twin driver multicell, & even with the teensy original Altec amp was more than enough for that 2600 seat barn. I had line on getting the cabinets from a 60's house which had just closed & used THREE of the W's for the screen speakers, but it was not to happen.  |  IP: Logged Kenneth Wuepper Phenomenal Film Handler Posts: 1026 From: Saginaw, MI, USA Registered: Feb 2002 posted 12-20-2002 08:03 AM                     On a recent job I found screen Left and Right new JBLs and the center was a new Altec. The problem was that you couldn't understand the dialog but it was plenty loud. Inserting the pink noise card into the CP-55 showed that the center channel was out of phase. Reversing the feed to the Altec corrected the problem. I am happy to know that this was not a component problem but rather the installers error. KEN  |  IP: Logged Paul G. Thompson The Weenie Man Posts: 4718 From: Mount Vernon WA USA Registered: Nov 2000 posted 12-20-2002 03:19 PM                     I can see a potential problem with speaker re-cone jobs by third-party vendors, namely terminal polarity. Steve, has this been a problem yet?  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 12-20-2002 11:03 PM                     Whereas we have always been a JBL, EV and Altec authorized service center, we are prohibited from using non-factory parts except at the customer's written instructions (which will void any existing warrantie(s). I suppose we are not "authorized" for Altec at the moment, since we have not opened up with the new owners of Altec. Irrespectively, we always obtain our Altec parts right from the source so they are genuine when we are done. In fact, during EVI's brief control of Altec, we use the correct parts, not just what EV would supply. So, Paul, to answer your question, I haven't come across any polarity reversals. Having seen 3rd party recone parts in JBL drivers, there were much worse things than polarity issues....like the wrong voice coil entirely! Just because a drive makes sound again doesn't mean it will perform correctly. Steve  |  IP: Logged Michael Schaffer "Where is the Boardwalk Hotel?" Posts: 4143 From: Boston, MA Registered: Apr 2002 posted 12-20-2002 11:50 PM                        David, "theatre" - British spelling; "theater" - US spelling. From Greek "theatron" derived from "theasthai" - to behold I like the article except that it refers to illustrations not included in the pdf file. That sucks (from Old English "sucan")!  |  IP: Logged Paul G. Thompson The Weenie Man Posts: 4718 From: Mount Vernon WA USA Registered: Nov 2000 posted 12-21-2002 12:33 AM                     I just checked a Altec 515C woofer that I had reconed about 12 years ago in Bellingham. I have never used it yet. Positive 1.5v on the Positive terminal does cause the cone to move outward as Steve suggests about Altec speakers. I have a JBL speaker in an Altec 1205 (Portable A-7, I guess) but I have not checked it yet. I think I will soon....just to be sure that speaker in that box is not phased wrong. The 515C I have was supposedly my replacement for the JBL in that enclosure.  |  IP: Logged

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