I listened to the driver a little more.
OK. the sound is nice. It is completely diffrent driver now. It sounds dark, smooth, kind of wood sound.I've noticed everything is located "higher" in the space. And also no detail is missing, maybe there is even a tiny bit more information they reveal.
but the highs are still rolled off and missing. The air is missing.
Now I wonder what coused the reduction in highs. As I said busted by 2uF cap some 3-4 db above some 12Khz sounded very good. So there are two options:
1. Either orginial dust cup with round hole was somehow magic.
2. Or painting whizzer with dammar coused that reduction in highs.
Maybe I will make some dust cups similar to orginal to see how it works.
What can be done to extend the higs through phase plug shape? Does anyone know?
Should it be exponetial, round , like in PM4A or regular bullet and straight.
How important is the air gap between phase plug and the cone?
Mine are a bit too small and the gap is quite big. Maybe even 2mm around.
Bartek
OK. the sound is nice. It is completely diffrent driver now. It sounds dark, smooth, kind of wood sound.I've noticed everything is located "higher" in the space. And also no detail is missing, maybe there is even a tiny bit more information they reveal.
but the highs are still rolled off and missing. The air is missing.
Now I wonder what coused the reduction in highs. As I said busted by 2uF cap some 3-4 db above some 12Khz sounded very good. So there are two options:
1. Either orginial dust cup with round hole was somehow magic.
2. Or painting whizzer with dammar coused that reduction in highs.
Maybe I will make some dust cups similar to orginal to see how it works.
What can be done to extend the higs through phase plug shape? Does anyone know?
Should it be exponetial, round , like in PM4A or regular bullet and straight.
How important is the air gap between phase plug and the cone?
Mine are a bit too small and the gap is quite big. Maybe even 2mm around.
Bartek
Hi, see its a while since anyone posted on this thread, but anyhow. Incase anybody's interested, I'm using the phaseplugs from Planet10. I'll post a few pics, installation was very easy, just gently stroke the scalpel round the edge of the dust cap, then scrape away any remaining little bits. I went for the light colour ones, because they had them in stock and i wanted a high gloss black finish anyway so was planning on painting them. Only listened to a few albums, but already well worth the 20UKP i paid (including postage), masses more treble detail, less hardness in voices, better imaging etc etc, generally more relax presentation, gives the impression of increasing the resolution of the driver. 🙂
Richard.
Richard.
Attachments
Those turned out very well. Excellent pictures... OK if i grab them (and the comments) and post them on my website?
dave
dave
An Olympus C-8080, not as good as an SLR or DSLR, but still takes nice pictures. Menna have the best image quality of any of the Semi-Pro 8Mpixel designs around 🙂 I'll go get a few really close, try and show you the cut edge aswell, although it really isnt noicable at all, and email them to you.
zygibajt said:
Hello,
I have used Dammar on a couple of different speaker cones and I think this may be the culprit. First cones I used them on was a pair of those ubiquitous Yamaha studio monitors with white cones and the peaky sound. Worked brilliantly on those. Really tamed the peakiness.
When I used them on a pair of kevlar (?) cones on the Optimus LX4 Pro, the sound got smoothed over to the point where the speaker sounded dead, with no snap or excitement. It was very smooth and warm, but no excitement or drive. Very shut-in sounding. Highs and air were missing.
I think the Dammar really does dampen the sound quite a lot, so the trick I think is to use it in very, very thin coats. I think you should cut it down with thinner a LOT before you use them on your cones. Then only use one coat at a time until you think the sound is right. Otherwise, you may dampen them too much.
I've used C37 lacquer as well, and I think it is a major step up from Dammar. It increases the richness and depth but doesn't seem to affect the highs negatively like Dammar does. The C37 reduces peakiness and adds a nice coherence, depth, and easiness to the sound, but it also leaves the dynamics, speed, openess, and excitement intact.
I used the C37 on a pair of Lowther DX-3s and also recoated the LX 4 Pro cones with some of it. It brought back a little life to the LX 4s, but I think the original coat of Dammar is still toning down the sound somewhat.
After my experience with these two lacquers, I'm only using Dammar on cones that are really peaky or resonant and are not very important to me. I'm splurging a little and usind C37 on drivers that I value highly if I think they need lacquer.
Best,
KT
Thanks for sharing your expirences.
Dammar makes the highs missing...maybe, but I found it was removing the dustcup that made the highs missing.
Many people say removing the dust cup makes the drivers sound better. Yes it does but only if you replace the dustcup with carefully fitted phase plug. In my case all the highs got back (at least I think all of them) after fitting the phase plug. And I think now the speaker sound better than with dustcup.
My speakers don't sound dead and I always put two very thin layers of dammar with soem 2-3 days period between painting.
What I like about dammar it maked the Fostex produce more bass.
Try to remove (they are removable) phase plugs from your lowthers and let me know if the highs are missing. I think they will.
Bartek
Dammar makes the highs missing...maybe, but I found it was removing the dustcup that made the highs missing.
Many people say removing the dust cup makes the drivers sound better. Yes it does but only if you replace the dustcup with carefully fitted phase plug. In my case all the highs got back (at least I think all of them) after fitting the phase plug. And I think now the speaker sound better than with dustcup.
My speakers don't sound dead and I always put two very thin layers of dammar with soem 2-3 days period between painting.
What I like about dammar it maked the Fostex produce more bass.
Try to remove (they are removable) phase plugs from your lowthers and let me know if the highs are missing. I think they will.
Bartek
Bartek,
Glad everything worked out with your Fostex drivers. It would have been a shame if the highs went missing forever!
Good to hear of your experiences, too. From my basic understanding of these things, a bullet phase plug like that found on the Lowther and the ones that Dave (Planet10) sells help guide the high frequencies out into the room so they don't cross and cancel themselves out right off of the driver. I suppose that's particularly important in a full-range driver.
The Fostex drivers are also full-range, no? What shape were the dustcaps originally?
I'm not using the Lowthers right now, but I'm sure you're right that the highs would cancel themselves out without the phase plug.
I purchase a similar set of phase plugs from Dave for some Foster FE103a that I got recently. I've only heard good thing about this mod. I'm glad it's working out for you, too.
Best,
KT
Glad everything worked out with your Fostex drivers. It would have been a shame if the highs went missing forever!
Good to hear of your experiences, too. From my basic understanding of these things, a bullet phase plug like that found on the Lowther and the ones that Dave (Planet10) sells help guide the high frequencies out into the room so they don't cross and cancel themselves out right off of the driver. I suppose that's particularly important in a full-range driver.
The Fostex drivers are also full-range, no? What shape were the dustcaps originally?
I'm not using the Lowthers right now, but I'm sure you're right that the highs would cancel themselves out without the phase plug.
I purchase a similar set of phase plugs from Dave for some Foster FE103a that I got recently. I've only heard good thing about this mod. I'm glad it's working out for you, too.
Best,
KT
Hi,
I was reading all this stuff about phase plugs and doping cones and couldn't help but wonder.
If the benefits are there, why don't fostex fit phase plugs to their drivers in the factory?
Doesn't doping the cones increase the moving mass and reduce sensitivity in the midrange? Perhaps it's this factor that gives them more apparent bass?
Also, wouldn't increasing the moving mass lower the Fs and increase the Vas?
I thought it was the low moving mass of these drivers (2.3g for the fe103 and 6.5g for fe166e) that was the attraction, so why add mass?
I'm not criticising by any means as I was thinking about trying phase plugs on mine. Just wondering.
I was reading all this stuff about phase plugs and doping cones and couldn't help but wonder.
If the benefits are there, why don't fostex fit phase plugs to their drivers in the factory?
Doesn't doping the cones increase the moving mass and reduce sensitivity in the midrange? Perhaps it's this factor that gives them more apparent bass?
Also, wouldn't increasing the moving mass lower the Fs and increase the Vas?
I thought it was the low moving mass of these drivers (2.3g for the fe103 and 6.5g for fe166e) that was the attraction, so why add mass?
I'm not criticising by any means as I was thinking about trying phase plugs on mine. Just wondering.
bobhayes said:
Phase plugs will let the sound be smooth, but some resolution is traded off. A better designed dust cap would be a much better solution IMHO. The dust cap really needs to be very stiff an light, which increases the cost of the driver.
bobhayes said:
You'd have to ask them. Certainly cost plays a role. Also reliability. With phase plugs there is more concern wrt dust & bits getting into the VC. And momentum no doubt plays a role.
I've almost been expecting to see a response from Fostex in the forms of product with phase plugs, but all the retrofitted units out there are likely just a drop in the bucket and haven't hit their radar yet.
The drivers we see are but a small fraction of Fostex's business, and Fostex is just a little spec of Foster.
The actual mass you add is not all that great. When i've modified RS 40-1197s & FE103A variants i run impedance curves on the drivers between steps. Unless you specifically add more doping the mass of the lost dustcap exceeds the mass of coating -- in these 2 drivers the VC sits proud of the cone leaving a nice V to fill up -- i use this as an opportunity to tune the drivers back down to close to the original Fs and 2 bring the drivers closer together in spec.
To read my speculations on why doping the cone helps check out this article -- note that i use puzzlecoat, and have just strated playing with dammar. I'd love to get my hands on some C37.
dave
soongsc said:
You cannot make such a sweeping statement. On the drivers i've been playing with, resolution improves.
dave
planet10 said:
Well, If you compare untreated paper VC caps with phase plugs, then the phase plugs are better. If you compare very stiff and light VC caps with phase plugs, the VC caps would be better. This is applies to a driver that covers up to 20K. Lower frequencies may not differ that much. I tried to understand this better when I did some comparisons and got some feedback also from people that had been conducting reviews for over 20 years. It had to do with how the pressure waves react differently with a phase plug versus with VC cap. Note that I do not have commercial interest in either.
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