Hello.
I wanted to get experts' opinions on something I'd like to do. I have been using ProAc Studio 200 since early 1995, and finally found that the foam edges of 18W8542 woofers were all cracked. I looked for some info. to replace or fix them, and found that options were $15/pc kit or $65/pc driver repair, or $2xx/pc driver replacement(could be cheaper, I guess). That just made me think that putting $300 or $900 to worry about the same thing 9 year later is not favorite. So, I changed my mind to replace all drivers and crossovers to make a new speakers. As I am poor at tools and woodwork skills, I just want to replace drivers which can be mounted in place of 18W8542 and seas 1" soft dome tweeter. I also believe I will have to redesign crossover for driver changes, but not sure even with redesign, I can get the right alignment of bass with existing enclosure and new drivers. But I want to try anyway.
Could you advise me whether this is feasible or not, which drivers to use, how to design crossovers, and internal dimension of Studio 200 enclosure, etc.?
I am looking forward to your kind advices.
I wanted to get experts' opinions on something I'd like to do. I have been using ProAc Studio 200 since early 1995, and finally found that the foam edges of 18W8542 woofers were all cracked. I looked for some info. to replace or fix them, and found that options were $15/pc kit or $65/pc driver repair, or $2xx/pc driver replacement(could be cheaper, I guess). That just made me think that putting $300 or $900 to worry about the same thing 9 year later is not favorite. So, I changed my mind to replace all drivers and crossovers to make a new speakers. As I am poor at tools and woodwork skills, I just want to replace drivers which can be mounted in place of 18W8542 and seas 1" soft dome tweeter. I also believe I will have to redesign crossover for driver changes, but not sure even with redesign, I can get the right alignment of bass with existing enclosure and new drivers. But I want to try anyway.
Could you advise me whether this is feasible or not, which drivers to use, how to design crossovers, and internal dimension of Studio 200 enclosure, etc.?
I am looking forward to your kind advices.
Replacing the surrounds is the best option by far , even if you
have to do it every ten years or so, but it should be the case
the new surrounds are more resilient than the originals.
If the surrounds are not too far gone repairing the cracks
and a coating of proper rubber glue can help matters.
sreten.
have to do it every ten years or so, but it should be the case
the new surrounds are more resilient than the originals.
If the surrounds are not too far gone repairing the cracks
and a coating of proper rubber glue can help matters.
sreten.
Disabled Account
Joined 2003
If you use different drivers then 95% chance you'll need a different crossover. Most likely you will a different port tuning too.
Which really means you're building a speaker from scratch, and by limiting yourself to that box will make it more difficult for woofer selection.
To really design a loudspeaker you need to mount a woofer in your intended enclosure, do some measurements and then crossover modelling. Install tweeter, measure some more and do some tweaking.
Doing it by math never really works properly.
Replacing/repairing the surround is often done and iIf you're happy with the sound of your speakers replacing the foam surround would be cheapest option
Which really means you're building a speaker from scratch, and by limiting yourself to that box will make it more difficult for woofer selection.
To really design a loudspeaker you need to mount a woofer in your intended enclosure, do some measurements and then crossover modelling. Install tweeter, measure some more and do some tweaking.
Doing it by math never really works properly.
Replacing/repairing the surround is often done and iIf you're happy with the sound of your speakers replacing the foam surround would be cheapest option
tktran,
Thank you for your informative reply. So, in example if I replace the 2 18W8542s to 2 18W8545s, I will probably get as high performance as the Studio 200 enclosure with 18W8545 can get, but it CANNOT be as good as original Studio 200. Am I understanding it correctly? Could you also tell me how successful this kind of modification(modifying crossovers, too) be NORMALLY?
Another question is, how much can a fine-tunable electronic or digital equalizer can help this problem. This may be too vague a question, but I would appreciate any answer to this stupid question.
Thank you for your informative reply. So, in example if I replace the 2 18W8542s to 2 18W8545s, I will probably get as high performance as the Studio 200 enclosure with 18W8545 can get, but it CANNOT be as good as original Studio 200. Am I understanding it correctly? Could you also tell me how successful this kind of modification(modifying crossovers, too) be NORMALLY?
Another question is, how much can a fine-tunable electronic or digital equalizer can help this problem. This may be too vague a question, but I would appreciate any answer to this stupid question.
Hello,
Well to answer your question... no it won't sound the same at all. If you look at the specs/the data sheet you'll notice that they are different. These numbers are the Thiel Small parameters, the characteristics of the speaker. Now if you were to plug those numbers in to a program like WinISD, which is free, you'll see that the response curve would be different. It would probably sound completely different, and I am guessing worse. Like tktran said, you'll be doing a lot of work for any changes you make, which could be fun, but you are basically redesigning the speaker. I agree with what the others said, in that you should just repair the surround. Too bad you didn't post 2 weeks ago, I just sold a pair of 8542s for pretty cheap. They are really good drivers, so it's definitely worth repairing. If you don't like your studios you should repair them and ebay them and get into the diy hobby with a speaker kit or something. You should head over to the madisound.com forum if you have more speaker questions.
Diamdiam
Well to answer your question... no it won't sound the same at all. If you look at the specs/the data sheet you'll notice that they are different. These numbers are the Thiel Small parameters, the characteristics of the speaker. Now if you were to plug those numbers in to a program like WinISD, which is free, you'll see that the response curve would be different. It would probably sound completely different, and I am guessing worse. Like tktran said, you'll be doing a lot of work for any changes you make, which could be fun, but you are basically redesigning the speaker. I agree with what the others said, in that you should just repair the surround. Too bad you didn't post 2 weeks ago, I just sold a pair of 8542s for pretty cheap. They are really good drivers, so it's definitely worth repairing. If you don't like your studios you should repair them and ebay them and get into the diy hobby with a speaker kit or something. You should head over to the madisound.com forum if you have more speaker questions.
Diamdiam
Diamdiam,
Thank you for your advice. I am now thinking of both ways, to repair, or to modify. One thing bothering me in repair way is that no genuine 8542 surround fix kit is known available. Do you know of anything like it? I contacted Meniscus audio for this, but they told me that the new surround will look thinner than the original. That may change the parameter of the driver too, I am afraid.
Thank you for your advice. I am now thinking of both ways, to repair, or to modify. One thing bothering me in repair way is that no genuine 8542 surround fix kit is known available. Do you know of anything like it? I contacted Meniscus audio for this, but they told me that the new surround will look thinner than the original. That may change the parameter of the driver too, I am afraid.
jheo,
that's a good question. i'm not sure what the answer is. in vance dickason's book there's a section on the mechanics of speaker parts. he shows that the material (foam, rubber and some new material) of the surround does change the parameters of the speaker. i don't know how audible it is though. the foam wil change the characteristics, but i don't know how significant it'll be. since it is fairly inexpensive, i would just get a kit and give it a try and hopefully the changes would be inaudible. i think if it is audible, only those few with trained and/or gifted ears could tell. i've read a few posts from people who've had repairs on old speakers and they didn't seem to be concerned with it. there's a few people over at the madisound forum that have done refoaming, so they'll have better knowledge and advice than me. good luck.
that's a good question. i'm not sure what the answer is. in vance dickason's book there's a section on the mechanics of speaker parts. he shows that the material (foam, rubber and some new material) of the surround does change the parameters of the speaker. i don't know how audible it is though. the foam wil change the characteristics, but i don't know how significant it'll be. since it is fairly inexpensive, i would just get a kit and give it a try and hopefully the changes would be inaudible. i think if it is audible, only those few with trained and/or gifted ears could tell. i've read a few posts from people who've had repairs on old speakers and they didn't seem to be concerned with it. there's a few people over at the madisound forum that have done refoaming, so they'll have better knowledge and advice than me. good luck.
Hi,
as i know branded speaker already match pair tested and the driver is custom,maybe they look same but the sound absolutly better than standard driver.if you repair or modification,that will complicated because that mean you will redesign all the enclosure,matching driver with crossover,and you must have expensive anechoic chamber room and analyzer.so i suggest you to replacement part but MUST order from PRO AC with your serial number.the sound will different when you purchase standard scan speak on the market.
Several year ago my friend speaker is broken at left tweeter,the standard tweeter use scanspeak 9500,he order from scanspeak and get new one,but after we replace the driver,very different sound with the original pro ac scanspeak driver...than we order from pro ac with give our serial number.pro ac send the scanspeak 9500, same model with standard scanspeak...but the sound is very different,better than standard,sound stage back to focus,high is same in both speaker...that why you must replacement the driver if want 100 % original sound.
as i know branded speaker already match pair tested and the driver is custom,maybe they look same but the sound absolutly better than standard driver.if you repair or modification,that will complicated because that mean you will redesign all the enclosure,matching driver with crossover,and you must have expensive anechoic chamber room and analyzer.so i suggest you to replacement part but MUST order from PRO AC with your serial number.the sound will different when you purchase standard scan speak on the market.
Several year ago my friend speaker is broken at left tweeter,the standard tweeter use scanspeak 9500,he order from scanspeak and get new one,but after we replace the driver,very different sound with the original pro ac scanspeak driver...than we order from pro ac with give our serial number.pro ac send the scanspeak 9500, same model with standard scanspeak...but the sound is very different,better than standard,sound stage back to focus,high is same in both speaker...that why you must replacement the driver if want 100 % original sound.
You can use a digital xover, look for the berhinger (sp?) digital xover, i think there's a few big threads on it some where around here. I've heard mix things about it. I think it's good because you can biamp, triamp, etc. (using an amp for each component, one for the tweeter, one for mid, etc.), and you can tweak with the settings like crossover order, point, etc. The problem is that you need to find a driver that would in your current box. Like I said earlier, each driver is different and needs to be tuned differently. If it's closed boxed it's a bit easier, but if it is ported it's a bit more complicated. The program that I mentioned before, winISD, can give you a plot of the frequence and impedence response. You just pick a driver from the programs database or enter in the T/S parameters and then pick a box size. However, this is just based on theoretical calcualtions and not real world measurements. In order to do that you need a measurement program and equipment like a mic and preamp.
Here's my suggestion, fix the surround, and if you don't like it learn about speaker building and make it into a hobby or get a kit. For the amount of time and money you'll be spending trying to rework this speaker it might not be worth it. Speaker design and building takes a lot of time and money, though worth it. You could try to find design based on your tweeter, I'm sure there are a lot of good designs available. However, sma is right that your tweeter might not be exactly the same as the one you can order at a diy shop. A lot of speaker companys have their own tweaked version of a common tweaker or woofer, and also component manufacturers change their design some times without changing the products model.
Here's my suggestion, fix the surround, and if you don't like it learn about speaker building and make it into a hobby or get a kit. For the amount of time and money you'll be spending trying to rework this speaker it might not be worth it. Speaker design and building takes a lot of time and money, though worth it. You could try to find design based on your tweeter, I'm sure there are a lot of good designs available. However, sma is right that your tweeter might not be exactly the same as the one you can order at a diy shop. A lot of speaker companys have their own tweaked version of a common tweaker or woofer, and also component manufacturers change their design some times without changing the products model.
Disabled Account
Joined 2003
The modified 9500 sounding better over the Scan 95 is probably just 6 and 2 threes ie they both are very similar, its just the xover in the speaker would have been designed for the modified version, so replacing it with a scan driver would alter the sound as the crossover would be different. Its highly possible that the proac modifier version was infact a custom 8ohm version which indeed would alter the effect the xover on the normal 6ohm scan driver.
Disabled Account
Joined 2003
jheoaustin,
Have a closer look at this:
http://www.speakerbits.com/net/misc/diy1.aspx
The pictures shown for repairing generic woofers are the same as that of the 18W8542.
I suspect the woofer pictures are used to show HOW to refoam them.
I suggest contacting this company to confirm if u decide to jump in.
Have a closer look at this:
http://www.speakerbits.com/net/misc/diy1.aspx
The pictures shown for repairing generic woofers are the same as that of the 18W8542.
I suspect the woofer pictures are used to show HOW to refoam them.
I suggest contacting this company to confirm if u decide to jump in.
Scan Speak 8542 re-foam
I would concur with those who suggest that your best option is to re-foam your existing 8542's. It is fairly easy to do using instructions shown on this website http://www.speakerbits.com/devdefault.aspx
I re-foamed four 8542's in October 2002 with kits obtained from Speakerbits and I experienced no problems. In an endeavour to increase the lifetime of the new foam surrounds I diluted some neutral cure silicone sealant with kerosene and painted both sides of the foam (taking care not to let the stuff get on the edges where they adhere to the cone and the frame) and let it cure for a few days before fitting.
Now I expect some members will gasp in hooror at my use of kerosene to dilute silicone sealant. It's just that I have used kerosene on all sorts of plastics for more than 30 years and I haven't found that it adversely affects 99% of them, unlike more volatile substances I could have used as a dilutant. I must admit that it did take some time before the silicone eventually absorbed all of the kerosene and became thin enough to paint a thin coating with an artists brush. I found it best to mix small batches as the kerosene doesn't take all that long to evaporate and the silicone becomes thick again. After several days curing the kerosene evaporates completely out of the silicone and so far I have noticed no deleterious effects to the foam.
I would concur with those who suggest that your best option is to re-foam your existing 8542's. It is fairly easy to do using instructions shown on this website http://www.speakerbits.com/devdefault.aspx
I re-foamed four 8542's in October 2002 with kits obtained from Speakerbits and I experienced no problems. In an endeavour to increase the lifetime of the new foam surrounds I diluted some neutral cure silicone sealant with kerosene and painted both sides of the foam (taking care not to let the stuff get on the edges where they adhere to the cone and the frame) and let it cure for a few days before fitting.
Now I expect some members will gasp in hooror at my use of kerosene to dilute silicone sealant. It's just that I have used kerosene on all sorts of plastics for more than 30 years and I haven't found that it adversely affects 99% of them, unlike more volatile substances I could have used as a dilutant. I must admit that it did take some time before the silicone eventually absorbed all of the kerosene and became thin enough to paint a thin coating with an artists brush. I found it best to mix small batches as the kerosene doesn't take all that long to evaporate and the silicone becomes thick again. After several days curing the kerosene evaporates completely out of the silicone and so far I have noticed no deleterious effects to the foam.