s 109

[scootersage]

hi
I have a set of s109's just had the drivers reconed and i think i need new crossover's. is there a replacement that would work good with these speakers. or should i just watch ebay thank's for any input.

[Earl K]

Hi,
Here's a .pdf tech sheet for your model of speaker . S109 Aquarius IV

I have a set of s109's just had the drivers reconed

- Any idea what recone kit was used ? ( ie; did ithey come back with black or white cones ? )
- Are they real JBL parts ?

,,, and i think i need new crossover's.

If I may ask; what has led you to this belief that you need new crossovers ?

,,, Is there a replacement that would work,,, with these speakers?

I'm not aware of any replacement crossover that provides better performance than the original network .

or should i just watch ebay ?

- Not very many S109s get parted out on eBay ( on an annual basis ).
- You can see from the schematic that these are pretty simple networks ( meaning , fairly cost effective to replicate ) .
- IMO, you'd be way ahead to rebuild ( or pay someone else to rebuild these ) using newer parts, if you really think there's a need .

[scootersage]

i have 3 sets of these speakers one pair i bought new in 1971 so i pretty much know what i have. was just asking if there was a replacement i could use. 2 sets have original thin paper and one set has the reconed heavy newer paper. one tweeter gets no power so i guess that means something is not working in the crossover, this set has the unit stapled and glued instead of screwed so getting at it to check means ripping it out. thank's anyway

[Earl K]

i have 3 sets of these speakers one pair i bought new in 1971 so i pretty much know what i have. was just asking if there was a replacement i could use. 2 sets have original thin paper and one set has the reconed heavy newer paper. one tweeter gets no power so i guess that means something is not working in the crossover, this set has the unit stapled and glued instead of screwed so getting at it to check means ripping it out. thank's anyway

Yes, I took the time to read all your older posts / so I'm hoping I now have a better grasp of your situation .

You might want to keep in touch with eBay seller " Mr. Hooptie " . I believe that just recently , he parted out some S109(s) . He might still have the crossovers . ( His LHF moniker is KingJames I think ) .

- FWIW, ( a quick explanation on the crossover )
(i) The woofer runs full range ( no low pass ). It does have a notch filter built into the woofer section that is centered around 1260 hz .

- For the white-coned le8, I'd be inclined to play a bit with the value of the 7.5 ohm resistor ( found on the woofers notch filter ). 4 ohms may be enough to smooth the peak .
- The white paper coned le8 may not be as peaky as the lighter black papered version ( all things being equal ) .

(ii) The tweeter hipass is quite simplistic. It consists of a variable 8 ohm Lpad , preceeded by a 3 uF cap. ( Those 2 parts wouldn't cost much money when purchased at Parts Express ) .

- Others here have reported some real sonic benefits in updating the caps on le25s ( the successor to the le20 ) .
- Straight old Dayton Metallized Polypropylene ( 3 uF in your case ) with AudioCap Thetas .01 uF "bypasses" seem to do the trick at opening up the resolution of these old paper tweeters . ( Just a thought ) .



*

[scootersage]

thank you for the input, I am a union electrician and altho i install sound systems in entire buildings i am not an electronics man. in fact i just scored 3 unused altec 944b anniversary amp's that were headed to the dumpster from a factory upgrade. I will take your advice and try to get them out and have them repaired. thank's again.