I just received my new surrounds for my L46 project. Got the first speaker all cleaned up and that is when I noticed the surrounds (old) are black and the new ones are gray. Contacted another member here who sells some and these are gray as well.
If gray is all I can get (current ones fit awesome!!!), can the surround take staining or will this screw up the characteristics of the surround.
Yank
I wouldn't mess. Let them be gray....
Why!!!
Did you ever think the old ones started out life as grey and then got dirty and turned black??
Here they are side by side. Note the gray surrounds are not glued yet. I put them together to see how the fit is.
Yank
Hi Bigyank,
From some research I did with the L46, the original surrounds were a very thin rubber that was black, very unusual compared to any previous surround material that JBL used, pro or consumer - mostly pleated cloth or paper (treated with the sticky goo sometimes), or single or double roll polyurethane foam of the time (80's-90's). AFAIK, the original surrounds were never available from JBL consistent with their not recommending refoaming/resurrounding.
In my discussions with a number of JBL service folks, the L46 must be refoamed with a standard foam surround (now a more stable polyether type) which for the most part are only available in a grey color. Some foams are shaped better for the cone profile and that would likely be the most important issue regarding fit. There are some differences in foams due to their thickness and springiness so getting them from a place that has had experience with the L46 driver or JBL stuff in total would be reassuring.
I have not seen any foam surrounds done in black in general. However, I have seen some in blue and Red (usually for Cerwin Vega).
Regards,
Bart
Thanks! I finished cleaning off #2 and yes, the surround was more rubber then foam and was a pain in the a$$ to cleanoff the back of the cone.
So now I am ready to glue, wish me luck! Oh and I do not have a 30 Hz source ready and I am doing it by hand. If the movement produces no sound, then that is it.
Yank
Funniest part is the woofers are still available on the JBL parts list for a measley 148.16 each.
Yank
In lieu of a 30 Hz source (I use 50-60 hz myself as these small woofers don't need to move at 30), you might just consider a good recording (or looped wav/mp3) that has some low bass content - you are using this to just get current and signal into the voice coil to keep it centered, so you don't need a really low signal and you don't need high volume. Really, just enough to see and hear the cone move freely without scraping. The signal itself will keep the VC aligned if the cone is moving.
Best of luck, if yours works, I'm contacting TG for some surrounds too!
Regards,
Bart
Downloaded http://mdf1.tripod.com/test-tones.html and burned 60 minute 50 Hz signal and will continuous play this through a CD player and a 40 watt/ch amp at low volume. Tomorrow morning is the moment of truth!
Yank
for refoaming i have a DC supply at like 2 volts with a polarity switch and it makes centering a whole hell of a lot easier. i also use the same CP Moyen glue you get with a recone kit. So it makes like easy
Sounds like a great idea. Would you please elaborate for this untalented monkey?Originally Posted by pelly3s
Thank you, Dave :dont-know
Last edited by norealtalent; 11-25-2005 at 06:26 PM. Reason: cant spell JBL
what i did was take a small 200mA variable DC supply and wire it to a dpdt switch so i can reverse the polarity of the output, and that is just wired to a pair of binding posts so i can use an assortment of leads off of it for multiple purposed. it then moves the cone assembly up or down depending on the polarity you have selected. now on certian jobs and outward movement helps more than on others. you will hear humming sound coming from the speaker and when it is rubbing you will hear sort of a rattling sound. just move the cone until it is centered and then let the glue dry
I have put the woofers aside for the moment and started looking at the tweeters. I am now in posession of a 2nd pair (thanks Duaneage) so here is my question.
The original 034 screens are silver, the ones I purchased from Duaneage are black. I kind of like the look of the silver ones but first glance is these are a bugger to open or better yet open with the intent to close again. Should I even bother?
Yank
Use a dental pick or toothpick to pull the rubber gasket from the groove where the screen sits. Practice on the bad tweeter first.
Duaneage thanks! I will have to get better light to do this. Will be trying tomorrow night. Wish me luck!
Yank
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