Not sure that you read the entire thread... I did these around 5 years ago and sorry, I dig into so many speakers that I don't take photo's. As I mentioned in the thread, after the crossovers were built, they had some sort of material poured on them and it dried encasing them. I chipped it away to uncover all of the parts, they came clean easy enough and the crossovers were then easy to modify. I hope this helps, Tim
Altec A7 What to do
Hello all, a Friend of mine has had Altec Lansing A7's sitting in his basement for several years, just couldn't put them in his current room setting. Many may know that I've been building for about 35 years. I built him a set of MTM's and delivered them for Christmas. He was thrilled. Well, today, he dropped off a pair of A7's and said they're yours. I sat them up and listened, thoroughly looked them over, looked up crossover design (500hz model) and now need to decide what to do with them. I have a decent size living room, but these are still huge. They do a lot of things right, but just aren't as refined as my current speakers. So, I've decided to sell them. I'm in no hurry to do so, but I know that I won't keep these forever. So, are these more desirable to sell as is... stock, upgrade parts in the crossover and sell them, redesign and trick out the crossover, cleanup, sand, minor fill and painting cabinets or some combination of the above. I have no doubt that a complete crossover redo, a bit of cabinet bracing and a good refinish and these babies would be incredible. The problem is... will people that don't know me accept or trust just how good they are? That being the case I'm looking for some advice. Please tell me how you would handle it in my shoes. Tim
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i am planning to replace the internal cables of the Altec A7 cabinet. i understand u have manage to open up the N500G crossover box, how easy to replace the internal cable that comes with that crossover box? i mean in term of accessibilty and de-soldering the stanadrd cables that comes with that N500G crossover box, if u have a photo of the internal of that n500g would be great |
Hi Kip, Not sure of your budget....If no budget, yes, get the Jantzen superior z in a 12mfd and a 6.8mfd..... If budget is an issue, take a look at Solen PPE caps... the other Solens are ok too, but I clearly Prefer the PPE, then get a Russian K71 polystyrene from Ebay.... this combination is very satisfying after a good break in...I have used the Solen, the K71 and Jantzen's all 3 paralleled together with very good results.... The K71 is very limited in its size availability.... they come in 1.0mfd.... 1.5mfd..... 5mfd and 10mfd. You could use 10mfd of the styrenes and 12mics of another cap with very good results... I don't care for ANY of the other Russian caps on speakers. There are certainly other good caps, but these are all very high bang for the buck, Tim |
@kipduff Hi Kip, If you are going to do a simple parts upgrade, measure the inductors, If they measure fine, just use them. If you are going to replace a diaphragm, if you can afford it, I’d replace them both. They could sound different from the originals and keeping them matched is important. Over time, I’ve played with alot of caps, for this project, I would replace C1 & C2 both with Jantzen Superior Z. Replace the resistors with Mills 12 watt non inductive. Overall these changes will be a true transformation to these speakers. |
timlub: I have similar components: 416A (16 Ohm), 802D (16 Ohm), 511B, and N-500-E. I have just aquired a pair of A7/828 empty cabinets. My XOs are dead and I'm considering rebuilding/upgrading them. If you are able, I could use some more detail. * how did you get rid of the tar? * brand/model/source of caps * brand/model/source of resistors I hink I have found an accurate diagram for N-500-E by "Peerless, Division of Altec Lansing". C1: 4 mFd, C2 18.9 mFd, L1: 5.4 mH, L2: 5.4 mH. Resistors: 2.5, 1.5, 1.5, 9, 6, and 10 Ohm. I'm pretty good at soldering and fabricating, but do not have understanding of how to select these capacitors and inductors and other details. Thanks, Kip.... |
There are damping materials you can get for cars that works fairly well: http://www.dynamat.com/automotive-and-transportation/car-audio/dynamat-xtreme/ (their website is pretty terrible..) There are of course many others. |
The link is good, but sometimes there is a problem, like right now, 10:22 am. Mid bass horn is what the woofer is at the back of. Filling the space behind the horn flares among other things to stiffen & mod the cabinet internals has been discussed. As well as covering the HF horn where some say it rings. Lots of stuff about the A7 cabinet. |
Thanks Gvasale, at least now, that link won't open for me. Don't know about a mid bass horn, there is a 15" woofer and tweeter (horn). I'm thinking about trying cutting to fit some self stick type materials and see how that works. I'll find something that works well. Plenty of ways to dampen the horn, mostly worried about the appearance since the horn is externally mounted. The cone mod mentioned in my last post was stiffening/dampening the woofer cone while replacing the dust caps. I hope to get your link to open later, thanks for all the suggestions. Tim |
You guys have been great, I made another change, so I thought I'd give you an update. 1 of the dust caps was dented. I bought a matched pair. I was lower mass (weight) than the original, with the 416A driver having a QTS of around .27, I really did not want lower mass. The factory cone is not nearly as stiff as I would like, so I made a 50/50 mix of Latex and Wood glue. I put 2 thin coats over the entire cone including the dust cap. I estimate that I lost about .2 db of overall sensitivity from the driver... (decrease from 99.5 to 99.3 and raised QTS to around .3, I still need to re port the cabinet, but again, Improvement, lower midrange detail is as well as the blend of drivers is better. Next I will do some experimenting with changing the vent tuning and try to find some attractive way to dampen the horn. These are actually a surprise to me. These big dogs sound very, very nice. |
Thanks for the vote of confidence Isochronism. To really improve these, it would take a crossover re design, I haven't run curves, but my instincts are that crossover point would move up to 600 or so and slopes would change from 12/12 to 12/18 to improve phasing. Then if I'm going to do that, might as well brace these cabinets. They really could use some re finishing.. easy enough. I could get lost in these and yes, they would be excellent. The bottom line is WAF won't go. Yes, I believe that I could over rule her and keep these, But my old body still functions and I'd like to keep an active (night)life. My current MTM's are very good and overall, I prefer them to the Altec's in their current form. These are very large and really could use a listening area larger than I have them in. I realize that some day, I'll kick myself for letting them go, but overall it my best call today. |
My band opened for Loggins and Messina in Honolulu in 1974 and they forgot to bring over their "side fill" monitors...so they borrowed our A7s (otherwise they used the huge Clair Bros. boxes). The first band to bring a serious PA on the road (to Hawaii anyway...on their way to Australia) with them was Bob Dylan and the Hawks (the Band without Levon for that tour) in '67 (other, earlier bands like the Stones in 1966 used the shitty "house" arena PA). A pile of A7s...Bob et al kicked ass, and it was the first sort of loud show I'd seen...life altering! |
I had bi-amps Altecs for a long time too. I ran transistors on the bass and an Ampex tube amp on top. When I went to tubes on the bass it got better; when I got rid of the electronic crossover and ran the tube amps full-range it got even better (although I had less power). When I ran the bi-amps setup I was in my 20s- just a dumb kid in school. I would put on Yessongs and play it a lifelike levels, by leaving the house and going to a friend's house three doors down and listening to it there... It was like being at an outdoor concert! My neighbors hated me. |
Just my two cents, but I think you would be better off to sell them as is vs. spending money on mods. The mods can be fun to do, but most people that are in to speakers like the A-7's will be DIY'ers anyway and will want to take on the project, not have it already done. For what it is worth, they were never my favorite loudspeaker. I used them for PA duty with various bands in the late 60's and early 70's, and they were decent, but not stellar. Most of us gave them up when better stuff from JBL came out. I worked in a stereo shop in the early 70's and sold one pair through that store. We set them up in our listening room and tried them with all sorts of amp/preamp combos. They sounded good with strong dynamics, but there was no getting over the "shouty" sound of the horn and the bass was a bit limited. Again, not the best sounding speaker in the store in my (and the other listeners) opinion, but they are a legend - for live sound, the first full range easy-to-drive PA speaker that could be moved relatively easily. |
I had a pair of A7s for years (in the 70s) and they sounded great and not so shrill really...we bi-amped them with crossovers in front of the amps, and they had this "wooden" sound that was really pleasing. Later we stuck heavy duty JBL bass guitar speakers in them for more serious "kick" miking and they still sounded great for simple home stereo use, although to make room for them you had to get rid of the furniture and drag the drunk groupies out onto the lawn. Worth it. |
They knew about WAF back then too, but then women were a bit different. Klipschorn, EV Patricians, Centurions, Georgians, Bozak Concert Grands, Jensen Imperials, Karlsons, to name a few. Altec Magnificents & a few other of their & the above showed that size does matter. I can always throw out "Hoffman's Iron Law" How many homes today have a piano? Let alone, bought one? |
Thanks Richard, the crossover did a great job of taming the midrange honky/shoutiness. There is the slightest bit left, but very minior and I believe horn damping will end that. After the crossover change, the lower midrange on these is just superb and the upper midrange oddly enough is a bit laid back. I did not expect that. At this point... in my room, I would not consider adding a EQ, but truly appreciate the input, Tim |
You may upgrade x-overs and brace cabinets, but for me, equalization cured the shout and the honk of my Altec Stonehenge 3, Klipsch La Scala and my present day Altec 17 and the latest VOTT. Nothing too expensive; a 230 dollar AudioSource 200 from Amazon can do wonders for a well fed horn. Also, try to keep your horns in the cabinet that they may better blend with the woofers. When they are perched on the cabinet, the sit way to high. These beasts were made to fill auditoriums, not residences. Cheers! Richard |
Hello all, as discussed earlier, I have replaced all the caps & resistors in the crossover with upgraded hand spec'd parts with less than 1% tolerance from one channel to the other. The improvement is not subtle. I've given these a couple hours of listening and they continue to improve..If anyone out there has A7's, this is a modification well worth the few dollars, clear improvement in the upper midrange through the treble region as well as a some improvement in soundstage and noticeable improvement in detail also. I know that the recommendation by one above is to "get over it" and keep them, but they are just too big. So I'm back to the original question. Am I spinning my wheels and wasting my money to do any more work on these, or am I just better off to sell them as is? |
The last iteration of the A7 you found was done by Altec *.* Technologies, if I got the name right. They were the sucessor to Sparkomatic. Their speakers were done by Great Plains Audio. I doubt they ever sold one at that price. Regardless, that version is no lobger. I think the brand name is owned by yet another company at this time. What's out there is still tons of fun. |
Broke away the encasing, measured all the parts, Measured all new parts and put together matched pairs for both crossovers, replaced the aluminum foil caps (very rare), and mylar cap, replaced resisters with mills, hot melted all in place in the first crossover. The parts are all matched & soldered for the second crossover, I'll tackle that in the next day or two and let everyone know. All I've done is replace crossover parts with High quality parts. If I get the gumption, I'll take full measurements and possibly add compensation circuitry... Don't know. |
Thanks to all of you guys. I have just opened the back for the first time. The tweeters impedance is not marked, but DC resistance is 8.1 ohms. The woofer is an 16 ohm 416A... The Crossover is an N500G. I can do little to the crossover, everything inside is covered in some sort of goo, at first I thought it was epoxy, but it isn't that tough. Caps look to be film & foil low voltage parts, then there is 1 - 2mfd mylar... I'm going to go ahead and put 400v poly props in place of the film & foils and 1mfd poly & 1mfd styrene in place of the 2mfd mylar, put some high grade wiring in and start there. I appreciate you guys. Tim |
Not that this helps although I found it interesting. I just did a quick search "Altec A-7 Modification" and found an article titled "Legend Reborn", and it turns out that Altec has Reissued the A7' a couple years ago. At the time of this article (at least) they are priced at $8600 pr. shipped. Many years ago a very good friend's older brother had a pair for his home stereo. I was a fan ever since:) |
Altec A7s are plentiful and very few haven't had some work done on them at some point in time. If I had your skills and knowledge, I'd trick them out to the max and then demo them at an audio show. The goal would be to become THE go to Altec A7 mod guy. Like I said, big Altecs are readily available and I imagine that with first rate mods they will do things that $20-30k loudspeakers can't. |
Thanks John, I have 416A, not sure of the horn driver, but the horn is a 511b... Have you done any work on these? I'm wondering if anyone has done impedance correction on both drivers and resonance compensation on the tweeter. I could easily do this and keep the original crossovers in place. I'm thinking it would be very audible. |
Thanks Ralph, yep, I've damped many a horns, but these are exposed and I'll either need to cover them or figure out some way to make them look reasonably attractive. I typically like butyl tape on these, but that would look terrible. As far as the diaphragm, I haven't pulled it, but I would have to assume that it is Aluminum, my buddy bought these in 1969. |
The horn can be damped, which has a nice effect on the midrange! There may be beryllium diaphragms available too. The originals are aluminum and have some breakups which make them less detailed and harsher. If so, these are the people to contact: http://materion.com/Products/Beryllium/BerylliumAcoustics.aspx The best amps for this applications are typically lower-powered tube amps- you don't need much to make these speakers sing. |
Thanks Dan, I'm inclined to do a simple re cap with high quality parts, then brace and refinish the cabinets... original finish was a gray paint. I may paint or even veneer them. Then the horn could really use to be damped, pondering how to do that attractively. Still wonder if its all worth my time. |
keep 'em. Get over how much floor space they take up. I have similar sized speakers stuffed with Altec parts, just like the A7. But with a 13 cubic foot IB enclosure, just with 2 416a woofers. My listening room is small, about 13x13x8.5. I enjoy the heck out of them. They don't need much power and with a sizeable map, say 100 wpc or so do a great job on all kinds of music. I do have mine bi-amped and have a home made passive crossover, coils made practicly out of unobtanium today. They could be duplicated. That much power with a system in the 100db/1 watt/meter is extremely dynamic. But they can be blown, your ears will burn at the same time. Some people may say the range is too restricted, but I say listen to them first. |
That would be hard to decide. I'm the curious sort myself, I afraid I'd have to find out just how good they could be. I did just that with a pair of ca 1975 Tannoy HPD 315 Dual Concentrics (raw 12" drivers), and they are incredible. You'll never know until, or if, you try. I'm saying this without any knowledge of the Altec A7's, so take what I've said with the appropriate amount of salt. I would be interested to hear what others will say. Regards, Dan |
