Hello guys! I'm thinking of applying some felt to the front of the baffel, of my 3.5 build to help reduce "jitter", as I havent rebated the drivers (lack of routing skills!). My questions are as follows:
1) How thick should the felt be?
2) What felt material is best suited?
3) How far/shape should the felt extend from the edge of the drivers (as I've seen beard shaped ones!)?
4) What type of adhesive should I use to attatch said felt (Id like an adhesive that could be easily removed from the baffel surface if no noticeable difference is heard)?
Please help!
Bill.😕😕😕
1) How thick should the felt be?
2) What felt material is best suited?
3) How far/shape should the felt extend from the edge of the drivers (as I've seen beard shaped ones!)?
4) What type of adhesive should I use to attatch said felt (Id like an adhesive that could be easily removed from the baffel surface if no noticeable difference is heard)?
Please help!
Bill.😕😕😕
I used some thin felt from the local craft shop around my tweeters, got a nice burgundy colour. Stuck it on with blutack - I'd used a wax finish which made it a bit hard to glue
🙂. You might want something a bit thicker if you're trying to hide the edges of the drivers though. At low frequencies it's only cosmetic.
🙂. You might want something a bit thicker if you're trying to hide the edges of the drivers though. At low frequencies it's only cosmetic.
I'm planning on getting some of this. Apparently the B grade felt is less dense and better for sound absorbtion.
I have flush mounted my tweeters but surface mounted woofers (for time alignment). The woofers are roughly 5mm above the baffle surface so I'm going to use 5mm felt. Will also probably experiment with the star like cuts around the tweeter as seen on some commercial units.
Also considering how to make a grill that meets up with the felt (that is don't make the felt go to the edge of the baffle and have a 5mm thick grill frame that sits flush with the felt)
I'm just planning at the moment not sure how it will turn out so just as interested in any replys to this thread as you will be 🙂
Tony.
I have flush mounted my tweeters but surface mounted woofers (for time alignment). The woofers are roughly 5mm above the baffle surface so I'm going to use 5mm felt. Will also probably experiment with the star like cuts around the tweeter as seen on some commercial units.
Also considering how to make a grill that meets up with the felt (that is don't make the felt go to the edge of the baffle and have a 5mm thick grill frame that sits flush with the felt)
I'm just planning at the moment not sure how it will turn out so just as interested in any replys to this thread as you will be 🙂
Tony.
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Best felt is not synthetic... wool or cotton. For outside of a box, wool felt is usually going to have the edge, but the new recycled cotton/denim felt that Bob at CSS is selling (in reasonable quantities) looks interesting for this kind of application.
http://www.diyaudio.com/forums/showthread.php?t=150054
dave
http://www.diyaudio.com/forums/showthread.php?t=150054
dave
what I've done a couple of times to hide the driver edges (I don't have a routerr) is cut a plywood baffle with holes the outside diameter of the drivers - glue that on the front of the box & it looks like the drivers are recessed. I angle the outside edges at 45deg.
(Router would look better though...)
(Router would look better though...)
Hey guys! I thought it all through (as best I could) and just gave it a shot. Here are some pics of the aftermath! What do you think????
P.S. Thats my pal Miller Jackson giving a hand!
P.S. Thats my pal Miller Jackson giving a hand!
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I used PVC electrical tape (which is slightly thicker than electrical tape). Since it's stretchy you can just tape it in a circle and no one will ever know (unless you're not good at taping in circles).
Perhaps not audiophile-grade, I don't know. It was what I had on hand.
- keantoken
Perhaps not audiophile-grade, I don't know. It was what I had on hand.
- keantoken
Oh, and by the way we used 1/4 inch acrylic felt. It was in a pre packaged bag of felt remnant. It's all I could find at "Michael's" (local craft shop)!
I used this thick clear liquid glue called "Fabri Tack". It claimed to be able to join fabric and wood, and well, it did. It was just a little pricey though, 8 bucks (US) for 4 ounces! Other than that I highly recomend it.
I used this thick clear liquid glue called "Fabri Tack". It claimed to be able to join fabric and wood, and well, it did. It was just a little pricey though, 8 bucks (US) for 4 ounces! Other than that I highly recomend it.
Did you notice a big difference in sound quality?
Post Script: Will you post a pic of them?
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I've used 2 or 3 layers of thin felt from the fabric store to cover the whole baffle front and edges. Well worth the low cost and a bit of time. Much cleaner sounding.
Felt will do little to control diffraction of a driver faceplate or frame for a surface mount. I've experimented a lot in that regard with measurements before/after. The only thing that did work was to cut a rectangular piece of cork and cut an opening for the tweeter that was a tight fit. The cork was the same thickness (5mm) as the tweeter faceplate. Coupled with some baffle felt it works fine. It doesn't look very good, though 🙁 . You could use any hard wood of similar thickness as the faceplate.
I'm not sure what's different about B grade. That link says it's F-10 felt, some of the best. Typical F-10 is pure white, so if it's got any color at all, it may be called B grade. Acoustically it should be identical if it is truly an F-10. I'd buy it if it were economical compared to other sources/types. White on a baffle, though...
The star shape looks nice, but there's nothing to recommend it. A plain rectangle, especially not fully centered around the tweeter will work better. I've measured that. Also, look at some respected, earlier systems such as Dahlquist, Snell and others and you'll see rectangles and offsets. That's as effective and maybe even more. Triangles are effective and easier to cut as well. Minimally just a straight piece about 1" x 6" of 1/2" or 1" thickness is all that's needed between drivers. It's also not because of surface mounting the woofer, that's of minimal impact to the tweeter. The driver diaphragm is the issue. Mounting technique has little to do with the problem of nearby driver diffraction, especially since the distance from tweeter to any point on a driver perimeter is constantly varying and also is not significant on-axis.
That should work fine. I've done that, put a 1" wide 1/2" thick piece of F-13 felt (F-11 or F-10 will do better) that "framed" the frame, so to speak, just inside. A full baffle covering will do better, but the frame approach will still be a significant improvement.
That's interesting looking stuff. I may try some of it.
Dave
I noticed a slight improvement in quality. A slight improvement to me could be a large improvement to you...
Tape would hold the speakers firmly given that they weren't warped enough to lift off of it between the screws (with my speakers if I screw them to tightly I'll warp the frame). My impression is that it doesn't matter so much to reduce jitter as it does to make what jitter exists smooth jitter, and direct metal-to-wood does not seem like optimal in this regard. My reasoning was that PVC tape, since it's stretchy, will form its own seal between the frame and box. The speaker frame actually sticks to the smooth tape when I try to take it off, so I guess I succeeded.
I will post pictures if I can.
- keantoken
Okay, here are some pics...
Sorry for the size.
The first is my whole system... Not very Hi-Fi!!!
Ask you can see I just taped in a circle, one half of the tape folded inside the hole. This is because the tape will pry itself off the front because of the tension. You have to let half of it loose so the pressure isn't too great... It looks professional, don't you think? 🙂
- keantoken
Sorry for the size.
The first is my whole system... Not very Hi-Fi!!!
Ask you can see I just taped in a circle, one half of the tape folded inside the hole. This is because the tape will pry itself off the front because of the tension. You have to let half of it loose so the pressure isn't too great... It looks professional, don't you think? 🙂
- keantoken
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Hey Tony! Hey guys!
Do they sound different???
Well, first let me thank PeteMcK, wintermute, planet10, keantoken, panomaniac, dlr, and last, but certainly not least, Moondog55 AKA “Ted” for putting the idea in my head to begin with!
My friend Miller, my wife Sarah, and I completed the work last night, though we were unable to audition them because of the late hour. Sarah and I however did audition them this evening and thought we heard a slight improvement.
However, after reading “dlr’s” post, we decided to add another layer of felt to the first layer, this time also covering the faceplates of the tweeter and midrange drivers. We then re-auditioned them………
Brothers, let me tell you this was the “single” largest improvement in sound since we attenuated the tweeters! I can’t articulate in words the improvement!!
Thanks again to everyone who posted!🙂
Bill.
P.S. Check out the new felt pics!
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It doesn't sound good, it just sounds better...
X_X
So I was more or less hesitant to reply. I do what I can with the parts at hand but someday, I'll have something real nice, starting with AKSA's latest amp...
- keantoken
I'm sorry if I confused someone with this post. I was referring to my own system. I have no doubt that the one in discussion sounds brilliant.
- keantoken
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