908 0r 902?

[badtoby]

Can anyone ID these drivers?


PAIR ALTEC LANSING MODEL 14 MANTARAY HIGH FREQUENCY HORNS AND DRIVERS | eBay

[Altec Best]

They are OEM 902's with just a loading cap no rear covers.

[voice of the theater]

I agree. I own Model 14's and these look identical to the stock drivers in mine which are 902-8A with no rear covers so these are most likely the same drivers. Badtoby, if you're considering these for your Model 19's, I would recommend 802-8G's instead. I consider the 902-8A to be just as "great" of a h.f. driver as the 802-8G (I have 802-8G's in my 19's)-- both have phenomenal extended h.f. response and are very clean reproducers with excellent sonic characteristics/crystal clear sound but they do have a different timbre/sound/personality from each other. The crossover in your Model 19's was tailored/optimized to the 802-8G's characteristics (h.f. compensation, etc.) and there will be a substantial difference if you install 902-8A's into your 19's compared to the stock 802-8G drivers which were an integral part of their award winning design IMHO.....

[RonSSS]

So in simple terms, Altec threw away the award winning design when they switched to the ferrite drivers.
They made no change to the cabs or crossovers when they switched.
Pretty interesting huh?
That alone ought to slash the prices for the ferrite 19's.

Personally, I prefer the 902-8A HF drivers. They share the same lighweight diaphragm. I sold my -8G's.

Although these in this ad are the 902-8A, they aren't "good" unless you add the rear covers with felt lining and toss the loading caps.
You can find the rear covers from time to time. GPA will probably sell you some.

Ron

[voice of the theater]

So in simple terms, Altec threw away the award winning design when they switched to the ferrite drivers.
They made no change to the cabs or crossovers when they switched.
Pretty interesting huh?
That alone ought to slash the prices for the ferrite 19's.

I'm not sure but I think you're being sarcastic? (hopefully I'm wrong) It's no secret that Altec was trying to save money towards the end, and the switch to ferrite drivers (as well as some of the other changes in the last few years prior to 1984) were cost cutting measures--not performance improving measures. Do you think the 416-8C was an improvement over the 416-8B or a less expensive woofer that still "worked" in the 19's?

Personally, I prefer the 902-8A HF drivers. They share the same lighweight diaphragm. I sold my -8G's.

Preferences are of course subjective--there is no right or wrong answer. However, to set the record straight here, in the interest of trying to keep this forum as factually accurate as possible, only the VERY early 902-8A's had the light diaphragms. The majority of 902-8A's that were manufactured did not. I have commented here before that I think the 902-8A/mantaray combination on my Model 14's is a "magical" combination that rivals the high end of my Model 19's. I really like the 902's as well. In the interest of being open minded I have no qualms admitting that I've never heard 902-8A's used with the 811 horns and the Model 19 crossovers. Maybe I'd really like them too--might be worth a try Badtoby. However, when I think of Model 19's, I think of the "classic" original award winning design. I own two pair of 19's and I wouldn't even consider changing a thing on them they sound that amazing now that I've replaced the original "worn out" caps. But that's just my opinion......

Although these in this ad are the 902-8A, they aren't "good" unless you add the rear covers with felt lining and toss the loading caps.
You can find the rear covers from time to time. GPA will probably sell you some.
Ron

O.K. This is why I joined this forum. I am not a "techie" by any means. I am finally learning some of this stuff from the good folks here. I have owned many different pair of classic Altecs starting in high school because they sounded better to me than other speakers I auditioned-never really understanding why. I guess being a musician, I've always had a musician's approach to my speakers. Like when I go to the guitar store and play 20 guitars or 10 keyboards listening closely to tone and taking into account playability/practicality--walking away with the one that sounds the best to me without really understanding why it sounds the best. That's how I ended up selling/upgrading various pairs of vintage Altecs through the years and ending up with Model 14's and Model 19's--they sound the best to me. If I understand this quote correctly, you're saying that I can get my 14's to sound noticeably better if I toss the loading caps and add rear covers with felt lining? If this is true, I'm going to have to try it. Ron, thank you. I've read here about removing loading caps and putting felt on rear covers but never understood that it applies to my 902's. Can anyone else confirm that this would be a suggested upgrade for "stock" Model 14's with 902's like the one's in the Ebay ad in this thread (mine look exactly like those)? Here's some pics of my 14's.....

[RonSSS]

I was actually being serious. As I stated in another post, the -8C is a different woofer and has different T/S parameters. Therefore the box is no longer correct for it. The 19 was not voiced with the -8C.
With the exception of the diafragm and the phase plug, the 902 and 802 are different annimals. I have heard both on the 811 horn and I prefer the 902. I believe it is excellent. Not as sexy though, can't say alnico.
Was Altec being cheap? Not real sure. Alnico became non existant at the time, so I believe it was out of necessity. Someone can correct me if i'm wrong.
I for sure would have preferred alnico 19's, but I found mine local, just a few blocks away. Beggers can't be choosers. I do really like them, but the LF isn't what I think it could be.


I have 2 pairs of 902-8A and both have the lightweight frams. Also have a pair of little known 806 drivers with tangerine plugs and the same lightweight frams. As Jim Dickenson (Yes, the Jim Dickenson) told me back in the 80's, don't blow them up. They are no longer available!

Nice speaks! I have never heard those.
Actual testing has been done, and a lot of ears here prefer the drivers you have with the end caps and felt. I'll let others comment.
Loading caps originally were used to limit fram travel in high power applications. I suspect Altec did cheap out in this instance trying to keep costs down.

So VOTT, didn't catch your name?

Tried to do the quote thing like you did, I'm too f'n stupid to figure it out I guess. [/QUOTE]

[bowtie427ss]

FWIW, IMO&E 902 wins hands down for HF extension. The older style 802's with the annular slit steel phase plugs will render the most "seamless" transition at 500hz and 800hz XO points. Ironically, for my preferences, this leaves the 802G as the least desirable in terms of sonic performance. A little further irony, even though i own examples of all the small format Altec drivers and am fond of them all, i probably spend the most time listening to Renkus SSD-1800's which, IMO, have a combination of the best attributes of the 902, and early style 802 all done with a diaphragm that has a mylar surround but should not be confused with a Symbiotik Altec.

[A7fan]

Note.....Renkus SSD-1800 diaphragms are no longer made, but if your quick......http://www.google.com/url?sa=t&rct=j...MOqR8g&cad=rja

[bowtie427ss]

Note.....Renkus SSD-1800 diaphragms are no longer made, but if your quick.....

I think i still have one NOS phragm left somewhere, i bought 4 about 10 years ago from a mastering studio not too far from here that was also a parts supplier for the microphone and speaker repair industry. I've never needed a replacement, so ebay'd the others off here and there for "play" money. I've never really counted, but i probably have ~50 working Altec/Emilar/Renkus small format drivers floating around here. I've got spares to last the rest of my lifetime, or for as long as i can still hear, whichever comes first.

FWIW, a few years back a gentleman(who's name escapes me, apologies) posted here or maybe at AK or both who had worked with Jonas Renkus. I think our friend Steve Schell can fill in the blanks where my memory fails, as i believe this gentleman was staying with Steve at or around the time of his posting. he gave some great insight into the diaphragm construction, i think he helped Renkus develop the "tri-laminate" material that the phragms are constructed from.

Maybe some of the old posts have survived the various server migrations, i'll do some searching and see what i can find.

[voice of the theater]

Nice speaks! I have never heard those.
Actual testing has been done, and a lot of ears here prefer the drivers you have with the end caps and felt. I'll let others comment.
Loading caps originally were used to limit fram travel in high power applications. I suspect Altec did cheap out in this instance trying to keep costs down.

I've read here before in posts by Old Guy and others that removing the loading cap and putting felt on the back cover was an upgrade for home hi-fi use (if you're not looking for "high power" protection). I guess I never understood what a loading cap really was/looked like. I knew my 902's didn't have a back cover as was customary in Model 14's, but didn't understand that what they had instead was in fact a loading cap. If I had known that it was a loading cap then I may have been able to put 2 plus 2 together and realize that I could upgrade them by removing that cap and installing a rear cover with felt...... As far as Altec's motivations for using a loading cap on the Model 14's instead of a back cover, it may not have been entirely a cost oriented decision IMHO. One of the things they boasted about with the Model 14's was the power protection circuitry. It was something that the Model 19 and 15 (it's predecessors) didn't have. I think they may have been genuinely concerned that very powerful receivers and amplifiers were becoming popular for home stereo use--and the prices on them had dropped so a lot of "average Joe's" who weren't even "audiophiles" were using powerful receivers for their home stereos. Altecs, of course, were extremely efficient speakers that could easily be destroyed by a powerful receiver/amp, so I'm thinking the power protection circuitry and the loading cap both appearing on the Model 14 may not have been a coincidence. Just a theory, of course..... However, they could have included a loading cap AND a back cover so eliminating the back cover altogether did save them some money

As far as the transition from alnico to ferrite, I think I heard somewhere that alnico was much harder to obtain at that time (and was very expensive). However, I'd like to think that Altec may not have been (entirely) negligent in switching to the 902-8A and 416-8C without making any mods to the cabinets/crossovers in the Model 19. I would hope that when the 902-8A and 416-8C were in the design/development stage, their goal hopefully was to design ferrite drivers (replacement drivers for their alnico "counterparts") that would perform as well or better than their counterparts in the same/similar applications (possibly including working as well or better with the same crossovers/cabs/etc.). From what Ron and Bowtie are saying, maybe they succeeded with the 902-8A but were not so successful with the 416-8C? Just a theory again, and yes, I'm going out further on a limb with this second theory......

FWIW, IMO&E 902 wins hands down for HF extension......

OK, you and Ron (who both seem to really "know your stuff") both prefer the 902-8A over the 802-8G. Do you guys mean the 902 with the light diaphragm, or with the 34647 diaphragm? Or do you mean with either diaphragm the 902's "beat" the 802-8G's with light diaphragms. I'm not sure when Altec stopped making the light diaphragm ( I read somewhere maybe here it was by the late 70's or 1980?), but by 1981 they had definitely stopped making them (maybe earlier). My Model 14's have AFAIK the original diaphragms with a 1981 date code that matches the year of the drivers and cabs, and they are 34647. Both pair of my Model 19's (from 1976 and 1978) have light diaphragms (23744). Anyways, I have said here before that the 902/Mantaray combination on my 14's rivals the 802-8G/811b combination on my 19's IMHO. However, even though they rival them, if I had to pick an overall favorite, it would be the 802-8G/811b combination. It sounds "warmer" to me for lack of more precise terminology. However, probably not a fair comparison as my 902's don't have a back cover with felt like my 802-8G's (and also don't have the light diaphragm that my 802-8G's have).

So, does anyone have some kind of description as to what kind of improvement I'm likely to hear if I remove the loading caps on my 902's and install rear covers with felt? Will it be like a toothpaste ad--will they be cleaner and brighter, warmer, or roll off at a higher frequency--any or all of the above? I'm seriously considering buying a used "early" pair of 902's with light diaphragms, and doing three experiments.
1) take their back covers and install them (with felt) on my 902's (in my 14's) after removing their loading caps to see how the sound "improves".
2) After listening to this upgrade for several days, then swap out the light diaphragms on the used 902's that I've bought with the 34647's in my 14's and seeing how that "improves" the sound.
3) Removing the 902's (now equipped with light diaphragms and back covers) and installing them into one pair of my Model 19's too see how I like them compared to the 802-8G's. If I like them better, I'll keep the used 902's I just bought--and start looking for another pair for my second pair of Model 19's. If not, I'll sell the used 902's I just bought but I will sell them with 34647's installed and loading caps, and keep the rear covers and light diaphragms for my Model 14's. I'd of course, be willing to sell them at a loss on Ebay or wherever to compensate for the fact that I bought them with light diaphragms and rear covers and sold them with 34647's (providing I like the light diaphragms better in the 902's) and loading caps without rear covers......

If I prefer the 902's in my 19's over the 802's, I know I'd have two pair of Model 19's that are kind of "Frankensteins" at this point--Ferrite 902's with Alnico 416-8B's, but I want what's going to sound the best and If there's a way to get not only my 14's to sound better but even my 19's, I'm all ears guys! (and thanks for any info/advice from anyone here). I'm thinking even if I replace the 802's in my 19's with 902's, I'll most likely keep the 802's so I can return my 19's back to stock down the road if I want to. However, if the improvement is drastic, I can't say I'd rule out selling the 802-8G's. I guess I'd have to think about it--how important to me is the ability to switch them back to "stock" condition--especially if the 902's end up being a significant upgrade in sound......

BTW, Badtoby, I feel like I'm hijacking your thread but since you already had the drivers identified that you requested, I guess this may be useful info for you too. If I do these three experiments (I most likely will soon--hopefully after getting a little more "infopinion" here), I'll report the results in this forum.