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david45
04-23-2010, 11:49 PM
I'll be attempting to mate a pair of altec 808-8g on 511 horns with some jbl 2226 woofers (2x4648a-8). I'll be using an active crossover so that I can run the JBL with some pro amplifiers that I have on hand but I am not 100% sure what I should use to power the altec. I can't seem to find any specifications for the altec drivers online. I am considering buying a tim rawson gainclone as they are fairly cheap and could always use it in a different system if ever i'm not completely satisfied, but it would be nice to know the sensitivity and recommended power before I make a move. This is for a second system in a fairly large room that I would also occasionally use outdoor. If anyone could provide me with the specifications for the altec drivers that would be very appreciated
thanks in advance

david

Earl K
04-24-2010, 05:47 AM
http://www.lansingheritage.org/images/altec/specs/components/808-8b/thumbs/page1_small.jpg (http://www.lansingheritage.org/images/altec/specs/components/808-8b/page1.jpg)http://www.lansingheritage.org/images/altec/specs/components/808-8b/thumbs/page2_small.jpg (http://www.lansingheritage.org/images/altec/specs/components/808-8b/page2.jpg)

- Here's the spec. sheet for the 808-8B ( I'm not sure what driver you're using ).
- This sites Library ( where the above info actually resides ) is more or less off-line for now .

http://www.lansingheritage.org/_derived/index.htm_cmp_lansing-heritage010_bnr.gif (http://www.lansingheritage.org/)
- I'd recommend a crossover point of @ 800 hz / when using those 511 horns .
- Efficiency of either model driver on the 511 is @ 104 db ( BW limited to the midrange frequencies ) .
- Power handling is ( 30 watts pink noise ) if you actually have 808s ( and not 802s, as mentioned in your title ) .
- 802 diaphragms are notoriously fragile ( they only handle 10 watts of pink noise measured , 500hz -20Khz ) / & they are best not used with live music / though they're nice for home stereo usage .
- 50 clean watts ( measured into an 8 ohm load ) is an ample supply of wattage for these drivers .
- Don't underpower these drivers ( with only 25 watts ) and then run clipped square waves into them / you'll surely fry the voice-coils that way .

<> cheers

david45
04-24-2010, 09:47 AM
Thanks for your help Earl!! There is no inscription on the drivers but i was told they have the tangerine phase plug and from what i have seen online they would be the 802-8g, meaning I'll have to focus on home stereo usage ;) Thanks for mentioning the 800hz crossover point as I was planning from experimenting from 500-800hz. I'll let you know what I find as far as amplifier, but what I had in mind was one of those gainclones using the 3886 chip and I think they are good for 40 wpc at 8ohms and 50wpc for the dual monos... BTW would you also happen to know of a place where I can get the magnets recharged up here in Canada or is there only great plains audio? How do I actually know if they have to be recharged in the first place?

thanks again for your help

david

david45
04-24-2010, 10:40 AM
I went ahead an just bought a gainclone as I was able to find a nice one for $150... I just noticed in your last post that the efficiency was for a limited bandwidth so I guess I wont be able to rely on a SPL meter to make sure I don't damage the drivers if I am to use them with live music, right? this is getting complicated lol

cheers,

david

Earl K
04-24-2010, 10:43 AM
Magnet Recharging Services ( don't quote me on any of the following prices ) ;

- In your area, Belisle Acoustic (http://tr.ca) advertises that they re-magnetize drivers .
- They're reachable at 450 691-2584 but I hear they're pretty expensive ( @ $75.00 each recharge ) .



-Here in the Toronto area, http://i21.ebayimg.com/01/i/06/08/17/af_1_b.JPG Bob Santon has said he will recharge magnets ( I believe ) for a bit less ( maybe $ 50.00 ea. ) . santon55@yahoo.com (santon55@yahoo.com) I had Bob do a few @ 8 years ago / but I paid 1/2 that at the time .

- GPA is cheaper than either of the above. They will ( apparently ) include this service when you buy a pair of new diaphragms from them & ship your drivers to them for installation ( definitely the best deal going , if all true ) .


- Whether your drivers need recharging is really anyones guess . Overdriving alnico magnet-ed drivers will make them lose some of their charge .
- Nobody ever admits to abusing their equipment in these situations / so how is one to know ?

- If you were in the US , I would just recommend out of hand that you send your drivers into GPA to get new aluminum diaphragms ( then you start all new ) .
- On this side of the border it's more complicated ( & dangerous ) due to shipped packages having to cross international boundaries twice .


<> cheers

david45
04-24-2010, 03:03 PM
alright then I'll call Belisle Acoustic tomorrow as I'm hoping to see if it is possible to make sure that the alnico magnets actually have to be recharged before they make me pay for it... And I will also get in touch with Great Plains Audio to see what they have to say about their Pascalite diaphragm vs the original one (aluminum)... it would indeed be nice to keep the same tone and simply add a bit of power handling... again thanks for the info you are making me feel not very knowledgeable haha

cheers

dave