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I am talking about these tweeter rings! Any experience with these or something equivalent?
Follow Ups:
I used some very thin green felt with an adhesive back. The kind you put on the bottom of chair legs to keep from scratching the floor. I just used anough to cover the screw heads on my tweeters (Scan Speak 9300 silk dome).Huge difference in sound - for the worse. Closed everything in and muted the top end significantly. Just 4 tiny 1/4" dots around each tweeter did this. Took them away and everything came back.
I guess this tweak is most appropriate for metal domes which may not be as smooth as a silk dome, or may be over extending or distorting. Just MHO.
> I guess this tweak is most appropriate for metal domes which
> may not be as smooth as a silk dome, or may be over
> extending or distorting.Umm, check layman's posts, this has nothing to do with it. I'm not pitted toward one type of tweeter over another, but I know that metal domes are usually not more prone to distortion or being less smooth, where as fabrics can distort easier and that is nothing new.
Interesting scenario. I've experienced the exact same. One set of speakers that I own use a 19mm silk dome tweeter. Now, I am not generally a big fan of fabric domes, because they have a tendency to sound too "restrained." I am not totally sure why. I have studied and compared the response graphs for silk and metal domes. I don't see big differences EXCEPT in the high treble, where most silk domes appear to cut out early. They begin rolling off at 10 kHz and don't produce much extension above 16 kHz. This does not explain their "restrained" sound though. The graphs must not be showing what my ears detect, which is a difference in sensitivity and loudness (between silk and metal domes). Metal domes (generally) sound more sensitive and are capable of a louder treble.In my experimentation with felting, I have noticed that felt lowers the reflectivity of the baffle. Most speaker designers use the baffle like the reflective material behind a flashlight bulb, to increase the amplitude (brightness) of the tweeter's response and to focus that response in a forward direction. Therefore, the designers will often choose a highly reflective baffle (that functions as a wave-guide).
Felting lowers the reflectivity of the baffle and therefore also lowers the sensitivity of the tweeter. Very sensitive metal domes will not suffer too much of a loss, but less sensitive fabric domes (without a reflective baffle to amplify their output) will experience a significant drop in the amplitude of the tweeter's output.
So, the effects of felting depend on how the tweeter has been voiced vis a vis the baffle, but it stands to reason that a restrained sounding fabric-dome tweeter will sound even more restrained when it no longer has "boundary boost" from the baffle to assist its sensitivity. Felting may not be an option in such circumstances (unless the dome's sensitivity can be adjusted in some other way - perhaps by adjusting the crossover), which is unfortunate, because preventing diffraction effects using felt has other benefits (besides allowing consumers control over tweeter sensitivity) such as more stable imaging and a cleaner, less hashy treble sound.
It's worth spending some time experimenting with different amounts of felt and different baffle placement because each tweeter/baffle system has been uniquely voiced. Each system will have a slighty different sensitivity (to any other). Felting will alter the tweeter's sensitivity to one degree or another. Experimentation will provide just the right amount of fine-tuning to improve the quality of the tweeter's performance without losing too much sensitivity.
I thought I might share how I got around the loss of sensitivity with my speakers with the 19-mm silk dome tweeter. The speakers in question have a wide baffle and sharp baffle edges. When the treble wave-front reaches these edges, it re-rediates creating "reflections" that are no longer fully in phase with the primary wave-front. The primary and secondary wave-fronts interact constructively (producing peaks) and destructively (producing nulls) leading to rough, "saw-toothed" response at the listener position and smearing images. Wide-baffle speakers often suffer from vague imaging as a result of diffraction effects (the wider the baffle the greater the time difference between the primary and secondary wave fronts - wide baffles also push the interactions down in frequency towards the mid-range, where there is more musical information). Narrow baffle speakers (with sharp,un-rounded edges) experience the same effects, but at higher frequencies and with less time delay.Now, when I used the kind of felt damping ring around my 19-mm silk dome as I often use around metal domes, I experienced too dramatic a loss of sensitivity. To solve this problem, I removed the felt ring (around the dome) and instead placed felt strips along the upper and side edges of the baffle. This worked beautifully. The tweeter still benefited from the "boundary boost" provided by the reflective baffle, but diffraction effects where prevented from occuring by the felt strips.
When the tweeter's primary wave-front moved along the baffle to the baffle edges (where it would normally re-radiate upon encountering the edge) it was absorbed by the felt, keeping the forward sound (primary wave-front) clean and unaffected by peaks and nulls. The treble sounded much cleaner and suffered no loss of sensitivity and the stability of images also improved (images seemed to lock in place rather than suffer vagueness). Success!
I'll be filing these away for future resource. Thanks.If you know the Focal tweeter in the Paradox 1's, you know why I'm not hearing drastic reductions in detail or volume.
Hi Danda. I once made my own redition of these with some neoprene I bought locally, which I used with a pair of B&W 601's years ago. I remember it did seem to help but it was not a dramatic change. The idea there is good, especially with some speaker designs.Fast forward. Did you see my thread a couple days ago about using felt material around tweeters? You might scroll foward and find it, kind of interesting. I went to a local fabric store that evening and bought a bit of wool based felt and tried applying some felt around the tweeters of my Paradox 1's for fun, as it seemed this tweeter could be prime for damping it's diffraction characteristics because it is so wide in dispersion. I've only done one experiment, where I've applied a large amount around the tweeter and interestingly enough it's made a very positive improvement. The amount of treble does not seem diminished or muffled in any way, it simply sounds cleaner, slighty sweeter but the biggest improvement is clearer definition of treble and subsequently depth definition and image definition. On some recordings it has been striking, the feeling of presence and seeing into the stage has been nicely enhanced. I'm still experimenting, but it's definitely interesting and fun!
If anyone could take a digital photo of this felt application I would love to see exactly how it's done, ie thickness, proximity to the tweeter etc. I know it's very experimental but would like to see exactly how someone else does it.
Jeff
See how the neoprene imagers are mounted in this picture, this is basically the idea of using the felt too. As to thickness it's just one piece of felt, it's not nearly as thick as this neoprene. You just experiment by cutting varying sized rings. Size meaning width of the ring. Hope that helps.
Sean,Did you cut the felt in form of a ring? How did you attach the felt to the baffle. Double-back tape?? If I remember right, the Focal tweeter in P1 is a inverted metal dome which is flush mounted on the baffle. My Stratus Minis have a aluminum dome which mounted on the baffle where the baffle is kind of recessed like in small valley and the tweeter has a hard grille on top of it. I am wondering what is the purpose of recessing the baffle at the location of the tweeter and if any felt ring will adversely affect the response because of the recessed baffle.
My main purpose of the experiment is to see if I can get more focus. The tweeter is laid back compared to other speakers and I am not looking forward to reducing any further brightness since it may affect clarity/detail. O well, I guess I need to try to find it out.
Thanks for the feedback!
Contrary to the suggestions of others here, I decided to start with a lot of felt in my first run at this so I basically have the entire Focal tweeter's mounting plate covered with the felt, the hole around the tweeter coming very close to it's edges. Bold I know, but hey this is free and it can be removed and cut smaller in seconds. I got a ton of it for $3. I used regular old rubber cement. Rubber cement sticks nicely, does not damage, can be applied and reapplied several times before wearing out, and cleans up very easily by just rubbing off. You just brush it on the felt.I just checked out the PSB web site and I see what the tweeter looks like on your mini's. Since we are talking a mere few dollars here for the glue and felt I'd just give it a try. Try applying a ring close to the tweeter, try applying one a bit of a distance away, try large rings, thin rings, etc. The Reynaud Twins have a recessed tweeter like yours, they apply a felt ring around the edge coming from the tweeter to help diffraction from the immediate edge next to the tweeter. You might try felt very close to the tweeter too. Who knows.
As to focus versus losing detail/clarity, even with the huge amount of felt I have applied right now I have to say I have noticed no decrease in detail at all and clarity has only got better. I plan to listen for a day two more with this amount of felt and then try removing it to see if I can gauge what exactly has changed. So far I could not be more pleased. Like you Danda, I tend to like a more sweeter sounding treble but I like detail too. Though the Paradox 1's were not too bright or forward before, they now sound just as detailed but slightly sweeter and more focused. The focused images is a very nice improvement, it's like some background noise or high freq hash has been removed, leaving me with more music in space. Dekay described in one of his posts that just a small amount of felt made big differences on a pair of speakers in one of his experiments, in one case too much so where it took the treble down too much. Again, every case is different, but in my case this is not happening. It's not as if the treble sounds like a blanket has been thrown over it or anything like that, no muffling,
I'm simply noticing changes in the realm of "minor" or a "tweak."Hope that helps. Trial and error. It's cheap and totally reversable if you do not like it, and you are out only a few dollars but have it on hand for the future. Regular acrylic based felt can be found at about all fabric stores but if you can I'd call around and find one that has a content or percentage of Wool or cotton in it. Mine has a wool content.
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:) Rubber cement can be found at grocery stores, drug stores, home improvement stores, art stores, department stores, etc. Check in the paper/pens/folders/tape/paper clips/stuff like that sections. :)
I have used rubbers and have seen cement, but not together :-).
Can't imagine the combo, won't it hurt after the cement solidfies?
Come on, give us the recipe. We know it's the rubber cement and not the felt that changes the sound.
Jeff
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I have them on my Bottlehead Straight 8 speakers. Gave a bit better focus and clarity but the difference wasn't huge in my application. Didn't seem to do anything bad to the sound so I left them on.
I really dont like the Idea of something on the face of my speakers. My B&W's have a ring on the tweeter already and that helps (albeit i saw some people remove theirs in other forums with terrible results).
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hondadanda; Do a search under "layman". He has some very interesting things to say about felt around tweeters and even midranges. I tried one of his suggestions around a pair of AR 302's and to my ears it was a definite improvement. Total cost was 24 cents at Hobby Lobby...Bill
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