Hello guys. So i'm running 4 EV T18 boxes with RCF L18S800 drivers. Recently someone from the club i rented them clipped and fried all 4 of them so they payed for the rapair. One driver had allready been repaired a long time ago (they are 17 years old) so the guy couldn't repair it again, he had to order a recone kit for that one. He reconed it and it looks beautifull and works fantastic now.
The other 3 drivers did not need a recone, he just ordered a new coil from RCF. And a new upper suspension (cloth surround) because the old one started falling apart from age. The guy that i gave these drivers to for a repair is doing this job for 25 years and is the best in city.
Now these 3 drivers that he repaired are working well, but he didn't put any glue/doping material on the new cloth surround. So it looks yellow and you can see it's completly dry, there is nothing on it. I forgot taking a picture but it looks the same as this: http://www.diyaudio.com/forums/blog...surrounds-recone-subwoofer-surround_small.jpg
So as you can see, the air can now go trough the cloth material and it's very soft. You can feel , when you are touching the driver, how it's softer then the reconed one. When you give it some low frequencies you can tell it's moving more then the reconed one just by looking at it. When playing music they seem to sound similar, but when you give them a sinewave between 45 - 60hz. The reconed one is about 10dB louder. I listened to it and measured it. The guy in the store told me he never puts doping on the sorround because it just slows the cone down and isn't necessary. He repaired hundreds of S800 (and he is not lying, he is really known as one of the best in this job). He told me that the reconed one needs some braking in and they are going to sound the same later. But it still seems to me i should dope the cloth sorround since i have never seen an RCF 18 withouth doping on the cloth sorround.
What do you think about this?
https://www.youtube.com/watch?v=5CJxea-7Ftw&feature=youtu.be
The other 3 drivers did not need a recone, he just ordered a new coil from RCF. And a new upper suspension (cloth surround) because the old one started falling apart from age. The guy that i gave these drivers to for a repair is doing this job for 25 years and is the best in city.
Now these 3 drivers that he repaired are working well, but he didn't put any glue/doping material on the new cloth surround. So it looks yellow and you can see it's completly dry, there is nothing on it. I forgot taking a picture but it looks the same as this: http://www.diyaudio.com/forums/blog...surrounds-recone-subwoofer-surround_small.jpg
So as you can see, the air can now go trough the cloth material and it's very soft. You can feel , when you are touching the driver, how it's softer then the reconed one. When you give it some low frequencies you can tell it's moving more then the reconed one just by looking at it. When playing music they seem to sound similar, but when you give them a sinewave between 45 - 60hz. The reconed one is about 10dB louder. I listened to it and measured it. The guy in the store told me he never puts doping on the sorround because it just slows the cone down and isn't necessary. He repaired hundreds of S800 (and he is not lying, he is really known as one of the best in this job). He told me that the reconed one needs some braking in and they are going to sound the same later. But it still seems to me i should dope the cloth sorround since i have never seen an RCF 18 withouth doping on the cloth sorround.
What do you think about this?
https://www.youtube.com/watch?v=5CJxea-7Ftw&feature=youtu.be
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Wonder where he gets the undoped cloth surrounds? Hmmm...
If these are bass bins, then I would definitely put some doping on the surrounds. If air can go through the surrounds and/or the dustcap then the effective parameters are altered somewhat. Otoh, if the performance is ok, then it may not matter.
It makes little sense that the recone is 10dB louder at 45-60hz, except that there must be a difference in the cone mass and/or the VC is different (more turns in the gap).
There are very light compounds that can be put on the surround, so that is not an issue as far as changing the compliance of the surround enough to be concerned about.
Glue should never be used on a surround unless the goal is to stiffen it, and even then glue is not exactly what is called for anyhow. (imo)
If the new surrounds are less stiff than the old, then at LF the TS parameters are changed. Probably it will not handle quite as much power, as it is likely to have less excursion control at LF, especially *below* Fs or F3 (in the box). So bottoming out the driver becomes a concern in live sound situations, unless there is a HP applied to keep the subsonics out.
It will also have an effect on what the cone will do at higher freqs as the termination of the cone at the outer edged is changed. Could be better or worse - likely different somewhat.
All merely my opinions...
_-_-
If these are bass bins, then I would definitely put some doping on the surrounds. If air can go through the surrounds and/or the dustcap then the effective parameters are altered somewhat. Otoh, if the performance is ok, then it may not matter.
It makes little sense that the recone is 10dB louder at 45-60hz, except that there must be a difference in the cone mass and/or the VC is different (more turns in the gap).
There are very light compounds that can be put on the surround, so that is not an issue as far as changing the compliance of the surround enough to be concerned about.
Glue should never be used on a surround unless the goal is to stiffen it, and even then glue is not exactly what is called for anyhow. (imo)
If the new surrounds are less stiff than the old, then at LF the TS parameters are changed. Probably it will not handle quite as much power, as it is likely to have less excursion control at LF, especially *below* Fs or F3 (in the box). So bottoming out the driver becomes a concern in live sound situations, unless there is a HP applied to keep the subsonics out.
It will also have an effect on what the cone will do at higher freqs as the termination of the cone at the outer edged is changed. Could be better or worse - likely different somewhat.
All merely my opinions...
_-_-
By what he says he gets it directly from RCF Italy. I'm quiet sure this might be true. Every audio tehnician i know recomended the guy. What do you think is the other possibility. That he got aftermarket cloth?
These are Electro voice T18 boxes. Bass bins yes. I usually low cut them at 35hz and high cut them about 100hz. The boxes are horns so drivers move quiet free. But these repaired ones without doping a bit too free from what i see. From what i hear i think they start reaching xmax sooner now. They get that ringy/too much membrane movement sound earlier then the reconed one. They are just too soft and move to free. They have less excursion control yes. I have recorded a one minute video showing the reconed one running at 50hz. And then the repaired one at 50hz with the same input power. I'll upload it now so you can take a look and listen.
Questions, where do i buy the right doping material?
Can i buy a black doping material? Yellow cloth looks a bit silly.
Doping shouldn't be hard to do right?
These are Electro voice T18 boxes. Bass bins yes. I usually low cut them at 35hz and high cut them about 100hz. The boxes are horns so drivers move quiet free. But these repaired ones without doping a bit too free from what i see. From what i hear i think they start reaching xmax sooner now. They get that ringy/too much membrane movement sound earlier then the reconed one. They are just too soft and move to free. They have less excursion control yes. I have recorded a one minute video showing the reconed one running at 50hz. And then the repaired one at 50hz with the same input power. I'll upload it now so you can take a look and listen.
Questions, where do i buy the right doping material?
Can i buy a black doping material? Yellow cloth looks a bit silly.
Doping shouldn't be hard to do right?
https://www.youtube.com/watch?v=5CJxea-7Ftw&feature=youtu.be
Here. Take a peak at the video. The first bass bin in the video is the reconed one.
Here. Take a peak at the video. The first bass bin in the video is the reconed one.
I reconed a 3015lf myself and was worried I had done something wrong when they sounded horrible. Then I realized you could blow right through the surrounds. I bought this stuff to dope the surrounds and seal it up.
Speaker Repair Adhesive, Sealer, Cloth Surrounds, Foam Surrunds, MI-1291
Works great now.
This video shows that stuff being used.
http://youtu.be/x6CCrLz-Zts?t=38m11s
Speaker Repair Adhesive, Sealer, Cloth Surrounds, Foam Surrunds, MI-1291
Works great now.
This video shows that stuff being used.
http://youtu.be/x6CCrLz-Zts?t=38m11s
Thank you. I really can't believe, every audio guy in the city told me, get them streight to the "xyz" guy, he is the best in reconing and repairing. And he puts absolutley nothing on the yellow surround. The driver is so soft now.
Can i get this glue in black? I'd really like to see my surround black, it looks alot better.
Can i get this glue in black? I'd really like to see my surround black, it looks alot better.
you can put some black dey( ofarbati)in it .
it would be wise the weaterproof the cones aswel.
i think original rcf cones are stiffer.
i don't know how costly the repair was,buty you can alwais put an original recone kit in.
edit / the repaired one hes a lighter conus an lighter suspension.
maybe in your box they preform "better" > then you can do the last one also.
edit2/original rcf
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Well what he put in is the original recone kit. The package arrived from RCF Italy. I saw it myself. I don't think they sell exactly the same cones as 20 years ago.
Also what can be the cause of one driver clipping slightly earlier then the other one even when the amp is getting a mono signal. Can over excursion be the cause of this?
Also what can be the cause of one driver clipping slightly earlier then the other one even when the amp is getting a mono signal. Can over excursion be the cause of this?
There are many types and grades of sealers in the speaker industry. Unfortunately only a few make it to consumers, like the one cited above. It dries clear. So you could color the cloth itself. That's what I would do. Could be as simple as grabbing the guts of a permanent marker with a surgical glove and wiping one or more coats to make it black.
When you say a driver is clipping, what exactly is the thing you are calling "clipping"?
Btw, the stuff shown may or may not add enough stiffness to equal the original's characteristics. But more than one coat may be applied.
When you say a driver is clipping, what exactly is the thing you are calling "clipping"?
Btw, the stuff shown may or may not add enough stiffness to equal the original's characteristics. But more than one coat may be applied.
The T18 is a manifold design and they really only load the driver down to 50hz so your 35hz lowcut likely contributed to your driver failures, I'd suggest you raise that up to 45hz. Did you get a definitive cause from the reconer? Were the voice coils burnt or physically damaged from over excursion?
Could i take a can of spray and just do one layer? The suspension should soak the spray and go nicely black. I don't think it would do any damage?
When i say a speaker is clipping i mean the red clipping lamp on my amp is going on earliear for one speaker then for another. So i have a peecker sound TVA 1800 amp (2x900w @4ohm, 2x585 @8ohm) These are 8 ohm drivers so he clips after the 585w point. So the amp is getting a mono signal and both channels are running at the same power. One side is sligtly clipping, the other one starts clipping only when i push the amp 20% further.
Conanski: They do still sound decent at 40hz. You hear them lees but you hear them. If lowcutting at something like 45hz they loose some juice. I saw the coils when the guy took them out. 3 of them have been completly black but not deformed. The 4th one had been slightly fried and still not deformed. I have a picture of that 4th one that was in best condition. But we still replaced it:
http://i30.photobucket.com/albums/c316/athlon-64/IMG_0057_zps6389faa1.jpg
When i say a speaker is clipping i mean the red clipping lamp on my amp is going on earliear for one speaker then for another. So i have a peecker sound TVA 1800 amp (2x900w @4ohm, 2x585 @8ohm) These are 8 ohm drivers so he clips after the 585w point. So the amp is getting a mono signal and both channels are running at the same power. One side is sligtly clipping, the other one starts clipping only when i push the amp 20% further.
Conanski: They do still sound decent at 40hz. You hear them lees but you hear them. If lowcutting at something like 45hz they loose some juice. I saw the coils when the guy took them out. 3 of them have been completly black but not deformed. The 4th one had been slightly fried and still not deformed. I have a picture of that 4th one that was in best condition. But we still replaced it:
http://i30.photobucket.com/albums/c316/athlon-64/IMG_0057_zps6389faa1.jpg
Athlon,
I have bought recone kits from OEM's that include untreated cones, and you need to treat them once installed. So it does not surprise me that the repair guy got them untreated. Most recently this happened for a Beyma 10XC driver I did. This kit included a bottle of doping compound and instructions for its applicaton.
The photo you originally linked to from my blog showed a sub that I reconed using an aftermarket kit. I had to buy the doping material seperately. The supplier knew exactly what I was after when I called him.
Here is the bottom line:
- For a bass driver, you need to dope the surround.
- There is no choice, as the Q in the box is completely and utterly destroyed. What does this mean? That driver in a ported enclosure showed the SAME impedance as the driver in free air. The enclosure resonance did nothing at all.
- Without doping the surrounds the loading from the enclosure will just not be working, and your speakers will die a very early death.
So you are worried that doping the surrounds might stiffen them up a bit?
- OK, worst case it will. But...
- That is a lot better than doing nothing, as you will very rapidly destroy the drivers as they will be "unloaded" at low frequencies.
If I were in your shoes, I would have a very direct talk to the repair guy. If he does not understand the implication of not completing the job, then you need to talk to someone else. Alternatively just buy some and do it yourself. If you can colour in a picture then you can apply doping compound, you simply paint it on until the cloth is "wetted". I bought my last lot from "Queensland Speaker Repair" though I am sure you have plenty of people closer to you who can supply the required material.
Is the above coming across as being very direct? I hope so - as I was utterly stunned at how completely the lack of doping destroyed the performance of the driver. And how immediately applying doping put things right.
I have bought recone kits from OEM's that include untreated cones, and you need to treat them once installed. So it does not surprise me that the repair guy got them untreated. Most recently this happened for a Beyma 10XC driver I did. This kit included a bottle of doping compound and instructions for its applicaton.
The photo you originally linked to from my blog showed a sub that I reconed using an aftermarket kit. I had to buy the doping material seperately. The supplier knew exactly what I was after when I called him.
Here is the bottom line:
- For a bass driver, you need to dope the surround.
- There is no choice, as the Q in the box is completely and utterly destroyed. What does this mean? That driver in a ported enclosure showed the SAME impedance as the driver in free air. The enclosure resonance did nothing at all.
- Without doping the surrounds the loading from the enclosure will just not be working, and your speakers will die a very early death.
So you are worried that doping the surrounds might stiffen them up a bit?
- OK, worst case it will. But...
- That is a lot better than doing nothing, as you will very rapidly destroy the drivers as they will be "unloaded" at low frequencies.
If I were in your shoes, I would have a very direct talk to the repair guy. If he does not understand the implication of not completing the job, then you need to talk to someone else. Alternatively just buy some and do it yourself. If you can colour in a picture then you can apply doping compound, you simply paint it on until the cloth is "wetted". I bought my last lot from "Queensland Speaker Repair" though I am sure you have plenty of people closer to you who can supply the required material.
Is the above coming across as being very direct? I hope so - as I was utterly stunned at how completely the lack of doping destroyed the performance of the driver. And how immediately applying doping put things right.
Yes and believe me i'm still shocked by the fact that the guy who is doing this job for 20 years and is recommended by everyone in the country just looked at me and sayed. Oh i don't treat the surrounds, that just slows the driver down for nothing.
I sent an email to RCF italy. They repied quick and told me yes. The original cloth surround is yellow. So he did not lie to me about it being an original cloth surround. But they also told me it needs to be treated but RCF themselves don't sell the treatment. So now what i'm about to do is get a bottle of the damn glue and treat the cones.
I remember that on the old surrounds, if you scratched the treatment / surface od the surround, you could see the yellow material below. Witch means the treatment used for the surround is originally dyed black. Damn if i could just get that black treatment!
Look at this picture: http://i30.photobucket.com/albums/c316/athlon-64/IMG_2452_zpsa0992ce1.jpg
That's one of my S800's pictured this summer. Not take a good look at the surround slightly left from the red terminal. See the small yellow dots? Those are places at witch the treatment didn't go trought well so they remained yellow. So the conclusion is, they sell original yellow surrounds. But they are supossed to be treated!
I have a party i need to do this saturday with the subs. I don't have time to treat them right now. What should i do to prevent damage. Lowcut them a bit higher?
I sent an email to RCF italy. They repied quick and told me yes. The original cloth surround is yellow. So he did not lie to me about it being an original cloth surround. But they also told me it needs to be treated but RCF themselves don't sell the treatment. So now what i'm about to do is get a bottle of the damn glue and treat the cones.
I remember that on the old surrounds, if you scratched the treatment / surface od the surround, you could see the yellow material below. Witch means the treatment used for the surround is originally dyed black. Damn if i could just get that black treatment!
Look at this picture: http://i30.photobucket.com/albums/c316/athlon-64/IMG_2452_zpsa0992ce1.jpg
That's one of my S800's pictured this summer. Not take a good look at the surround slightly left from the red terminal. See the small yellow dots? Those are places at witch the treatment didn't go trought well so they remained yellow. So the conclusion is, they sell original yellow surrounds. But they are supossed to be treated!
I have a party i need to do this saturday with the subs. I don't have time to treat them right now. What should i do to prevent damage. Lowcut them a bit higher?
One out of 4 drivers got a full OEM recone kit. And that one is working fantastic now.
The other 3 drivers did not need a recone, just a repair. A repair included a new coil and a new cloth surround. He ordered both of those from RCF and installed them. But he claims the cloth surround does not need doping. Witch is just stupid.
The other 3 drivers did not need a recone, just a repair. A repair included a new coil and a new cloth surround. He ordered both of those from RCF and installed them. But he claims the cloth surround does not need doping. Witch is just stupid.
I don't know what to advise you here.
My drivers were in a ported enclosure. The performance was rubbish with untreated surrounds as previously discussed. Yes, you get some bass, but as you noted not a lot.
In a horn loaded system, I expect that things will be at least as bad, if not worse.
Can you talk to your repairer to see if he has some suitable material? Else borrow some drivers / enclosures off him for the weekend?
My drivers were in a ported enclosure. The performance was rubbish with untreated surrounds as previously discussed. Yes, you get some bass, but as you noted not a lot.
In a horn loaded system, I expect that things will be at least as bad, if not worse.
Can you talk to your repairer to see if he has some suitable material? Else borrow some drivers / enclosures off him for the weekend?
I don't think i can, i really need my boxes. I was testing them allready. They work quiet well withouth the doping, but not as good as they do with the doping. In the club i'm running them in i also have 4 yamaha CW218V. Dual 18's. Here is how it looks when we set it up:
https://fbcdn-sphotos-h-a.akamaihd....16_1587881531443701_6729732226219140778_o.jpg
So what i can do and that might be a good idea is. Run my EV'S as kickers (70-135hz) and run yamahas as woofers (35-70hz) So i will avoid doing too much mechanical stress to my EV's.
Sounds like a good idea?
EDIT: No it has got no clear doping. I checked 15 times. It's naked and air can go trough it. You can feel with yours finger it's completly dry.
https://fbcdn-sphotos-h-a.akamaihd....16_1587881531443701_6729732226219140778_o.jpg
So what i can do and that might be a good idea is. Run my EV'S as kickers (70-135hz) and run yamahas as woofers (35-70hz) So i will avoid doing too much mechanical stress to my EV's.
Sounds like a good idea?
EDIT: No it has got no clear doping. I checked 15 times. It's naked and air can go trough it. You can feel with yours finger it's completly dry.
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