Altec 908-8A Drivers - How Much Improvement over 807?

Hi, just looking for some advice from more experienced users of Altec small format drivers. I currently have 807 drivers with aluminum aftermarket diaphragms. I have a chance to get some 908-8A drivers locally for around $125 for the pair. They have no diaphragms in them and no back covers either. But they are in good shape and have the tangerines, etc. One thing that I was wanting to know is how much of an improvement would the 908s be over what I already have? I'm looking for more hi frequency than the 806/807 is giving me. Also, I noticed the one of the tangerines is black and the other is orange in the 908s. Not that it makes any difference but I wondered why they were different? I'm guessing they were made in different years. Please tell me what the advantages and disadvantages are making this swap. I realize the 908s will probably need to be crossed-over higher and will not have as good midrange as the 806/807 that I have now. But I think the 908s will have better upper-end treble and crispiness. Another scenario is that I just buy Altec Pascalite diaphragms and put them in my 806/807 drivers that I'm using now. Which way do I go with it all? I love the midrange the 806/807 can push out but the high-end treble is lacking somewhat. I do have them on an electronic adjustable crossover with CD Horn button (engaged to get any decent treble but it's not enough on the upper end). Thanks in advance!

Brad

Wow, nobody at all??? I thought this was THE place for Altec discussions, etc. I don't have much time to make up my mind on the 908s at that price...

servers/hosting is screwed up

Get them, there's nothing to lose at the entry fee.

Frequency response will be shifted upward, better HF extension, and you'll gain a few db of sensitivity, but you won't want to cross them as low as you would go with an 807.

Part of the problem is you have aftermarket frams that could be your issue. But Bowtie's info is acurate.

I realize the aftermarket diaphragms ARE an issue. But I don't know if GPA ones are going to give me that much more HF extension. I like the midrange the 806/807 give and the treble is okay. But I need to crank the treble on my preamp all the way up and also have to keep the CD Horn button engaged. This is the only way I can get decent useable HF out of them. Without the CD Horn button engaged; forget it. I don't get enough treble at all. I also realize the 908s will need to be crossed over higher. They claim you can go down to 500hz but I wouldn't do it. I was thinking maybe 1000-1200 hz would be more like it. I like to get them LOUD sometimes. Anyways, thanks for the input. I may just go ahead and get the 908s. I was hoping that putting Pascalite diaphragms in my 806/807 drivers would be enough to boost the treble and extend it out more. I'm not sure it would though.

If you get real frams you could try them in both bodies. the newer xover has HF EQ

The magnetic charge in the 806/807 bodies could be questionable depending what kind of life they've seen. The 908 bodies will almost certainly retain their full charge. There could potentially be a significant difference between new phragms in the 908 bodies and what the OP is listening to now, just no way to really know for sure short of trying it.

The charge on the 806/807 bodies seems to be strong as they are very efficient like they should be. But this wouldn't have anything to do with the lack of extended high frequencies. I just think it's the diaphragms more than anything. Maybe I'm just expecting more from them than they can do. I have a pair of 808a drivers with older (good) diaphragms in them and they have a lot better HF extension. I have tried my aftermarket diaphragms in the 808s and they sound fine. Plenty of top end. So I'm just thinking it is the 806/807 natural sound. Don't get me wrong, it's not unbearable and they sound okay but nothing to blow your mind. Now the 808s sound great; especially with diaphragms that were in them when I bought them. I'm going to try the 908s and get the Pascalites too. If all is good then, I will probably sell the 806/807 to pad my pockets again. Thanks for all the inputs guys, I really appreciate it. Just wanted a reality check more than anything. Make sure I wasn't going backwards with this change.

And if EQ-ing the horns , new prams and drivers still won't do it for you....you can do like some here have done and add a tweeter by-passed in at 3k or higher. This tweeter OG mentioned a few weeks back is one I have used with 511/806 (home application).
Vifa BC25SC06-04 1" Textile Dome Tweeter 264-1028
(BTW-never felt a need to add tweeters to EQ'd 808 b's / 802 g's)