Frankenstein monitors

Immanuel · Post by **Immanuel** » Sat Sep 11, 2004 8:55 am

(This is a copy of a topic I wrote on another forum. So please excuse my SP explanation)

I just made some Frankensteins, and so far I am very happy about them. I have till now used Epos es11 Hi-fi speakers as monitors, and they are not very suited for the purpose, as they are designed far more for pleasing than for detail and accuracy.

But at the University where I study, a couple of JBL 4411 where about to be thrown out. There was no more foam surrounding the woofer. So I took them home and did some surgery. I took out the woofers and the wires going from the x-over to the woofers, so nothing could short circuit. I keeped the es11s as woofers.

Then in the Scope Platform (the real time environment for Creamware cards) I made a 48dB/octave x-over in the modular. After that, I turned down the signal to the es11s to match that of the JBLs (they play on different kinds of amps - other vice I think the JBLs would be loudest).

The result/observations (in no particular order) after 1 hour
1) I have noticed, that it has become easier to sing along to the songs.
2) The stereo field is more stable, and the window much is bigger both horizontally and vertically.
3) I prefer the tonal character now. It is less upper midrange boxy.

Till now I like it. Maybe I find some cons later. Anyway my purpose of writing this here is, that it may inspire somebody. I believe there are a great deal of old monitors out there with deteriorated foam surroundings. My guess is, that many of these can be had for bag of bonbons. So if you are on a tight budget and really need usable monitors, maybe a start could be a set of these old warriors with some woofer you can get for cheap or already have from another system. For me the only cost was about 1½ hours of carrying/screw driving/arranging/tweaking.

[ This Message was edited by: Immanuel on 2004-09-11 10:03 ]

Post by **garyb** » Sat Sep 11, 2004 12:50 pm

you can get the jbl woofers reedged for a very small price by the local pro speaker reconer. the foam edges fail all the time. reedging is a very common operation.

Immanuel · Post by **Immanuel** » Sat Sep 11, 2004 12:59 pm

I thought of that too, but will it not change all parameters of the woofer - turning it into something completely different from the original intension? May still be worth a try though.

AndreD · Post by **AndreD** » Sat Sep 11, 2004 4:16 pm

the modular is , imho, not phase-coherent!

Immanuel · Post by **Immanuel** » Sat Sep 11, 2004 4:39 pm

Are we talking single samples or more? One sample at 44.1K equals to move one's body about 0.8cm. So in this context, it wouldn't matter. If you are talking several samples, it may be an issue.

Post by **garyb** » Sat Sep 11, 2004 9:26 pm

go to the jbl reconer in your area. reedging may alter the response from what a worn out edge might show, but it shoouldn't cause too much trouble... i have a pair that were reedged and they work great. foam edges don't last long, maybe a few years, smoke and air pollution beak the foam down. the constant flexing eventually causes failure. i usually pay about $10 u.s. for the job. afterwards the speakers are as good as new.

Immanuel · Post by **Immanuel** » Mon Sep 13, 2004 5:29 am

Well, I had a feeling, that things would be sucky here in Denmark. And it apears I was right. I contacted the Danish JBL import firm, and they answered 2640kr a piece. That is 433$ LOL - and included a full renovation. I couldn't resist but answer:

Well, I can not do much but laugh about that price. I wrote with a guy from Los Angeles, and he said that he paid ~10$ a unit for reedging. Considdering, that it is fairly easy to find much better drivers at a lower cost, I am just happy, that I asked for the price before turning the units in for repair.

Have a nice day - it hopefully isn't your idea about the "funny" price - LOL.

I don't remember having ever answered like this before, but that price really is a joke. My guess is, that they can not do the job and would actually go for a replacement - or they hoped to sell a new monitor. Sorry JBL, I do not have the finance to keep a set of your speakers maintained.

Thanks for the idea Gary. It seams Denmark is too small a place to get that kind of service. Or maybe I just have to find somewhere else to get the job done. At the price they gave me, it would even be cheaper to mail the 10 1/4lb units to you with some extra cash for the effort of getting the job done and sending them back. But nah, I find something else to spend my money on.

Post by **garyb** » Mon Sep 13, 2004 11:49 am

if they come, i will fix them.

really, there's a speaker reconer somewhere in the area. they don't have to be jbl edges. i'm sure that you're right about the price. that man was trying to sell you new speakers.

at any rate, don't throw them out as they can be made as good as new sooner or later....

Immanuel · Post by **Immanuel** » Mon Sep 13, 2004 12:34 pm

I found a place on the net. It is 300Km from here, and they charge 80$ a piece for foam and 90$ a piece for rubber. It is a better price. Still I wonder, if I really want those woofers 200$ much (including shipping). I will keep them, and I am lucky one day I find some local guy who will do it still a bit cheaper.

Post by **garyb** » Mon Sep 13, 2004 11:22 pm

at those prices they must be including a recone(the complete rebuilding of the speaker). really, it's a simple matter! all you need is just the reedge.

*edit* what's more i own a pair of the 4408s and they were reedged more than 5 years ago(still working...)

[ This Message was edited by: garyb on 2004-09-14 00:24 ]

nprime · Post by **nprime** » Sat Sep 18, 2004 11:23 am

The term is "surround". It is the speaker surround that you want to replace.

The reason that the rebuild seems so expensive is because the manufacturer's sell a kit for replacing the surround that included other parts which were sure to have been damaged when the surround failed. When the surround fails many other parts inside the driver start to rub against one another and degrade the performance of the speaker. The kit will include replacing all of the damaged parts.

I went through this with a pair of 15" Tannoys.

R

[ This Message was edited by: nprime on 2004-09-18 12:23 ]