I built a pair of very small (.11 cuft) two way speakers using the PE 269-570 drivers and the $1.95 Dayton tweeters. I used only a 1uF cap for a highpass to the tweeters (should be around 10K Hz IIRC). Possibly the lowest cost two-way system ever!
I mounted the drivers from the inside. I used a rounding over bit on my router to ease the corners and they ended up looking OK. My first listening sessions using a tube amp were pretty positive but the "bass" (hey you can only get so low with 4" drivers!) seemed a tad muddy, not like my multiple driver systems. Also there seemed to be a noticeable peak in the upper midrange.
I thought they might be OK speakers for my woodshop or something but not for HT. Then when I was at an art supply store I saw a bottle of Damar and remembered some people had positive comments about it.
I coated one driver with the stuff and let it dry overnight. I then listened again. There was a huge and positive difference to my ears with the coated speaker.
I brought in my son and asked him to listen, both speakers hidden behind a grill cover for a larger speaker so he couldn't see which was coated. I set the amp for mono output and switched between the coated and uncoated speaker. Every time with every type of music he said the coated speaker was dramatically better.
Repeat experiment with wife as listener. She is a much less critical listener than my son. Same results.
So my conclusion on this one type of driver in this one type of enclosure is that coating the cones makes a noticeable positive difference.
I'm thinking of coating the cones on one of my larger systems made with these same drivers. If it screws them up, hey I can replace all six drivers for under $3 US!
I mounted the drivers from the inside. I used a rounding over bit on my router to ease the corners and they ended up looking OK. My first listening sessions using a tube amp were pretty positive but the "bass" (hey you can only get so low with 4" drivers!) seemed a tad muddy, not like my multiple driver systems. Also there seemed to be a noticeable peak in the upper midrange.
I thought they might be OK speakers for my woodshop or something but not for HT. Then when I was at an art supply store I saw a bottle of Damar and remembered some people had positive comments about it.
I coated one driver with the stuff and let it dry overnight. I then listened again. There was a huge and positive difference to my ears with the coated speaker.
I brought in my son and asked him to listen, both speakers hidden behind a grill cover for a larger speaker so he couldn't see which was coated. I set the amp for mono output and switched between the coated and uncoated speaker. Every time with every type of music he said the coated speaker was dramatically better.
Repeat experiment with wife as listener. She is a much less critical listener than my son. Same results.
So my conclusion on this one type of driver in this one type of enclosure is that coating the cones makes a noticeable positive difference.
I'm thinking of coating the cones on one of my larger systems made with these same drivers. If it screws them up, hey I can replace all six drivers for under $3 US!
Oops
Steve,
Sorry about that. You are right, I was looking for drivers to repair a set of large 3 ways and apparently have Dayton on the brain.
The $1.95 tweeter is a Goldwood. (270-169) The highest frequency is only about 17K but what is there is pretty clean (and after years of listening to my music much too loud I probably can't hear any over 17K anyway
).
cancerkazoo said:
Steve,
Sorry about that. You are right, I was looking for drivers to repair a set of large 3 ways and apparently have Dayton on the brain.
The $1.95 tweeter is a Goldwood. (270-169) The highest frequency is only about 17K but what is there is pretty clean (and after years of listening to my music much too loud I probably can't hear any over 17K anyway
).
Sherman,
How many coats of Damar did you put on the 4" PR Pioneer? Did you do both front and back of the cone? Please let us know the results when you do all of them in your array.
I am about to coat the 10, 6" drivers in my arrays but am still trying different coatings on separate identical drivers. I'm in the process of experimenting with shellac, Weldbond (like white wood glue that dries clear and flexible) and an artist's glazing similar to mod-podge.
How many coats of Damar did you put on the 4" PR Pioneer? Did you do both front and back of the cone? Please let us know the results when you do all of them in your array.
I am about to coat the 10, 6" drivers in my arrays but am still trying different coatings on separate identical drivers. I'm in the process of experimenting with shellac, Weldbond (like white wood glue that dries clear and flexible) and an artist's glazing similar to mod-podge.
rcavictim said:
I used one coat on the front and one on the back. I wonder if doing the back is necessary though. When I applied the Damar to another set of drivers I could see that it was soaking through to the back.
The stuff I have is called Damar Varnish and is made by Windsor-Newton. It is very thin, thinner than mod podge, and so it soaks in to the paper cones completely. In fact after one coat the cones do not have any gloss to them. A second coat adds a little gloss.
I'm coating my array drivers this afternoon so I should be able to report back in a day or so.
Sherman said:
Please do report back when you have your results. I'm currently doing the same thing while building the baffles for my lines. I'm considering Windsor and Newton varnish as well as thinned rubber cement.
In my listening tests I wasn't sure I was able to tell the difference between untreated and one coat of varnish. I could definitely tell with two coats of rubber cement though. Too much rubber cement takes off the peak at the top end but they lost a lot of sensitivity.
Is this Damar varnish an actual real oil based varnish that thins with terpentine, paint thinner, etc?, or is it one of the newfangled water compatible coatings that go on white and dry clear?
I found that with the water based stuff, adding water to thin the product made the paper fibers in the cone get sloppy during the pricess and swell. Not so swell I think. This is an argument against trying to thin the water based glazes, but those are mostly so thick they do not really penetrate the paper cone.
I can see rubber cement killing the highs. I doubt whether they'll bounce back. You aren't always supposed to take the expression describing proof of performance, "where the rubber meets the road" quite so literally. I can see rubber absorbing a lot of HF energy.
I found that with the water based stuff, adding water to thin the product made the paper fibers in the cone get sloppy during the pricess and swell. Not so swell I think. This is an argument against trying to thin the water based glazes, but those are mostly so thick they do not really penetrate the paper cone.
I can see rubber cement killing the highs. I doubt whether they'll bounce back. You aren't always supposed to take the expression describing proof of performance, "where the rubber meets the road" quite so literally. I can see rubber absorbing a lot of HF energy.
One thing to remember with any of these cone treatments is to allow them to dry fully before listening to them. If you play them too soon you almost guarantee yourself a worse sounding driver afterward. Been there, done that, so learn from my mistake.
RCA,
Dammar is a natural varnish used to protect paintings and is definitely not water based.
RCA,
Dammar is a natural varnish used to protect paintings and is definitely not water based.
I bought about 50 of those 4" drivers and used 13 per side in a line array. I also used 4 of the Onkyo 3/4" tweeters per side at ear height, so I suppose it's a MTM/Line Array hybrid. I coated the fronts of the 4" drivers with "Tacky Glue" from a local crafts store. It seemed to significantly tame the 7K spike that those little ******s have.
My intention was to build these as a practice project and give them away to a deserving friend or family member. My immediate impression of them was that the mids & hights were crisp and detailed with a feeling of depth to them. However the lower midrange to their bottom was kind of muddy.
All in all I was pleased with the results and think they make an excellent speaker to someone who is far less critical than the average member of this forum (which probably constitutes 98 of the world's population).
My intention was to build these as a practice project and give them away to a deserving friend or family member. My immediate impression of them was that the mids & hights were crisp and detailed with a feeling of depth to them. However the lower midrange to their bottom was kind of muddy.
All in all I was pleased with the results and think they make an excellent speaker to someone who is far less critical than the average member of this forum (which probably constitutes 98 of the world's population).
rcavictim said:
The stuff I have is a real varnish that is designed to be coated over oil paintings as a protective coating. It is clear and very thin no body to it at all.
It is called "Superfine Dammar Retouching Varnish for Oil Colour" by Winsor & Newton. The "superfine" in the name leads me to believe there may be an "unsuperfine" version (maybe thicker?).
It soaks in to the paper cones rather than sitting on the surface and seems to dry completely in only a couple hours. I compared cones coated a few days ago with cones coated and allowed to dry for three hours. I touched each cone lightly with my finger and they felt the same. I then lightly brushed each cone with a cotton swab thinking any remaining tackiness would show as cotton fibers sticking to the cones, there were none. Lastly I lightly brushed the cones with single ply toilet tissue as it contains a fair amount of lint. No lint left on the cones. Hardly scientific but good enough for a 49 cent driver!
cytokine said:
OK, I have coated the drivers in my line arrays and have had a chance to sit down and give them a critical listen. Here is what I think.
This is after a single coat of Winsor & Newton Superfine Dammar Varnish to the front of the cones. I coated one speaker and not the other so that I could do an A/B comparison.
After coating with a single coat there is a subtle but audible difference in A/B listening. It wasn't as noticeable if I played a passage of music, stopped the CD, switched to the other side and then resumed listening. I think this is to be expected as "audio memory" (is there such a thing?) seems to be short, at least in my case.
What is the difference? It is so hard to describe sound in words! I guess I would have to say something like "slightly crisper" in the midrange, little or no noticeable change in the high end and a change in the bass.
I can't quite quantify in words what I hear in the bass. I don't think it has been attenuated or boosted. It just seems more distinct than before but the change is very slight and we (me, my wife and my son) all heard it but couldn't say it was necessarily better or worse.
Overall the change in the sound with a six driver "line array" was much less noticable than it was in a very small two-way using the same 4" driver and the same tweeter with the same cross-over cap.
However I did apply a coat to both the front and back of the two-way and only a single coat to the front of the array. I will apply a second coat to the back of the drivers today and maybe I'll have something different to report in a day or two.
Thanks for coming back with your impressions.
When I did my initial tests I coated one driver with one coat of varnish (slightly different product than yours but still a very thin Windsor and Newton protective varnish), and another with two. I also did one and two coats of rubber cement.
When they had dried I guessed that a single coat couln't have done anything to the sound so I didn't even bother to listen to them. I did listen to the ones with two coats of either rubber cement or varnish. Furthermore, I only compared the rubber cement to the varnish. Not a good experiment.
I will return to my treated drivers and evaluate the ones with a single coat based on what you have said.
I found two coats of varnish changed what I remembered the sound to be and that two coats of rubber cement really dampened the highs compared to the two coats of varnish.
I'm really in a quandry about what to do because I don't trust my hearing in this case and I don't have any measuring equipment.
When I did my initial tests I coated one driver with one coat of varnish (slightly different product than yours but still a very thin Windsor and Newton protective varnish), and another with two. I also did one and two coats of rubber cement.
When they had dried I guessed that a single coat couln't have done anything to the sound so I didn't even bother to listen to them. I did listen to the ones with two coats of either rubber cement or varnish. Furthermore, I only compared the rubber cement to the varnish. Not a good experiment.
I will return to my treated drivers and evaluate the ones with a single coat based on what you have said.
I found two coats of varnish changed what I remembered the sound to be and that two coats of rubber cement really dampened the highs compared to the two coats of varnish.
I'm really in a quandry about what to do because I don't trust my hearing in this case and I don't have any measuring equipment.
cytokine said:
I added a second coat of varnish to the array drivers of the "right" speaker, I kept the left speaker uncoated for comparison to the original sound.
Results? The second coat seemed to have some effect on the high end and virtually none in the midrange and little if any in the bass. The effect on the high end was to damp it somewhat, which is OK with these speakers since they were a bit bright (I actually used an l-pad to drop the tweeters 3 dB or so and this change improved it a bit more. I'm guessing another 1 or 2 dB?).
I am waiting on delivery of a test CD and some other equipment so that in the future I'll be able to make some objective measurements in addition to the subjective listening.
I have another set of two ways I built which are uncoated so they may be good candidates for some objective tests in the next few weeks. Hmmm, I wonder if the wife would shoot me if I made the walk-in closet into an anechoic chamber?
Chris8sirhC said:
I might be able to put some together when the test stuff arrives but it could take me a couple of weeks to develop some repeatable test procedures.
I would also be very interested in anyone else's actual objective measurements. Listening tests have limits (though in the end it is how they sound to your ears that should matter).
Sherman said:
I added a second coat of varnish to the array drivers of the "right" speaker, I kept the left speaker uncoated for comparison to the original sound.
Results? The second coat seemed to have some effect on the high end and virtually none in the midrange and little if any in the bass. The effect on the high end was to damp it somewhat, which is OK with these speakers since they were a bit bright (I actually used an l-pad to drop the tweeters 3 dB or so and this change improved it a bit more. I'm guessing another 1 or 2 dB?).
I am waiting on delivery of a test CD and some other equipment so that in the future I'll be able to make some objective measurements in addition to the subjective listening.
I have another set of two ways I built which are uncoated so they may be good candidates for some objective tests in the next few weeks. Hmmm, I wonder if the wife would shoot me if I made the walk-in closet into an anechoic chamber?
The walk-in closet could be a very close approximation to an anechoic chamber with all the hanging clothes...
I borrowed a friends RatShack SPL meter and did some non-scientific tests last night.
I found that two coats of rubber cement cost me about 4-6 dB over the meat of the range of the NSBs. This was a non-scientific test in my garage hand-holding the meter. It's entirely possible that my left channel is not as strong as my right (although I've never noticed a balance problem). The treated cone was always on the left and the untreated was always on the right.
However, when I switched out the rubber cement treated driver for the one with two coats of varnish applied in quick succession, I noticed a loss of only about 2 dB over the usable frequency range.
In both cases the top end was somewhat attenuated, especially so in the case of the rubber cement.
My current thinking is that a single coat of varnish should be the optimum treatment.
Interesting that you decided to use an L-pad on the tweeters. I too am planning an L-pad and have ordered the parts for 3, 4.5 and 6 dB of attenuation. I'm pretty sure that the one in the middle will be right. I'm building a 16/18 array wired to 8 ohms.
I added the wings to the baffles last night and the Mrs got to see it for the first time. Her comment was simply "that should be interesting". My comment? God's holy trousers! These beasties are seven feet tall with tapered wings angled back at 45 degrees. The wings are two inches wide at the top and ten at the bottom. The center baffle is 12 inches wide (Home Depot 12 x 3/4 x 96 MDF shelving). I can't wait to get these finished so I can wire them up and hear them...
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.