Baffle interface?; some dome tweeters are said to have such wide dispersion the baffle literally acts like a mirror at certain frequencies. This is why I used the term "splash" I have often used cork on the baffle front which also helps but having the felt right at the dome obviously absorbed enough off-axis energy; the apparent on-axis energy got smoother and better behaved. My guess anyway; I didn't have any measuring equipment at that point. In this case; I was mostly using these in a small, 2-way in the near-field like inexpensive monitors so the effect was very direct as opposed to maybe further out into the room as mid-field, etc...
I know Dunlavy used that way with a square close to the side edges of the front bafle for tweeter, sometimes mids. to limit the breakups with the enclosure as well and certainly also what is refered as a hot sound with first order filters (?).
For me the use of a first order would be for less passive parts and better delay integration if no active filter. But I understand it always needs a physical time alignment by moving back the tweeter to circa align on the mid voice coil.
Anyway I'm learning active filtering layout, Sure devices for the price of it and to avoid a dedicated pc with concolvers. Minidsp seems less hassle cause the mic and good REW soft of course. But if good filter setup is found with the Texas Instrument fiter soft, then it's always possible to go back with passive on the mid+tweeter to keep his own good DAC and stay active for the bass where the ears are less sensible :below 200 hz if I believe M&F curves 😀.
I believe the tweeter yu refer is this one JBL sourced for some of his hifi markett speakers, lot of choice with hard dome at Audax, but the motor designs are old : the voice coils can be sourced there as the whole tweeters
Dome tweeter Audax TW025A20, 8 ohm, 1-inch voice coil, 3.94 inch front
Dome tweeter Audax TW025A20Mg, 8 ohm, 1-inch voice coil, 3.94 inch front
Dome tweeter Audax TW025A14, 4 ohm, 1-inch voice coil, 3.94 inch front
Dome tweeter Audax TW025A28, 8 ohm, 1-inch voice coil, 3.94 inch front
Dome tweeter Audax TW025A16, 8 ohm, 1-inch voice coil, 3.94 inch front
short c2c and wave guided : https://en.toutlehautparleur.com/do...-8-ohm-1-inch-voice-coil-2-76-inch-front.html
smaller c2c : https://en.toutlehautparleur.com/do...-8-ohm-1-inch-voice-coil-1-57-inch-front.html
Want to try Audax titanium on a SB acoustic motor with some diy : https://en.toutlehautparleur.com/speaker-spare-parts/diaphragmes.html?p=12
Believe diaphragm are good at Audax but motors not as good as the usual brands we are talking to.
Edit : forgot also Manger star felt or of course the star felt pad of the Wilson audios' around their tweeters
For me the use of a first order would be for less passive parts and better delay integration if no active filter. But I understand it always needs a physical time alignment by moving back the tweeter to circa align on the mid voice coil.
Anyway I'm learning active filtering layout, Sure devices for the price of it and to avoid a dedicated pc with concolvers. Minidsp seems less hassle cause the mic and good REW soft of course. But if good filter setup is found with the Texas Instrument fiter soft, then it's always possible to go back with passive on the mid+tweeter to keep his own good DAC and stay active for the bass where the ears are less sensible :below 200 hz if I believe M&F curves 😀.
I believe the tweeter yu refer is this one JBL sourced for some of his hifi markett speakers, lot of choice with hard dome at Audax, but the motor designs are old : the voice coils can be sourced there as the whole tweeters
Dome tweeter Audax TW025A20, 8 ohm, 1-inch voice coil, 3.94 inch front
Dome tweeter Audax TW025A20Mg, 8 ohm, 1-inch voice coil, 3.94 inch front
Dome tweeter Audax TW025A14, 4 ohm, 1-inch voice coil, 3.94 inch front
Dome tweeter Audax TW025A28, 8 ohm, 1-inch voice coil, 3.94 inch front
Dome tweeter Audax TW025A16, 8 ohm, 1-inch voice coil, 3.94 inch front
short c2c and wave guided : https://en.toutlehautparleur.com/do...-8-ohm-1-inch-voice-coil-2-76-inch-front.html
smaller c2c : https://en.toutlehautparleur.com/do...-8-ohm-1-inch-voice-coil-1-57-inch-front.html
Want to try Audax titanium on a SB acoustic motor with some diy : https://en.toutlehautparleur.com/speaker-spare-parts/diaphragmes.html?p=12
Believe diaphragm are good at Audax but motors not as good as the usual brands we are talking to.
Edit : forgot also Manger star felt or of course the star felt pad of the Wilson audios' around their tweeters
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Diyiggy; nope, none of these are the same tweeter I had. I did see JBL used the same one but with a different faceplate. The surround looked like a circle of diamonds or XXXXXXXXXX shape all the way around; at first glance; like it was crinkled (well, it WAS crinkled but with a very specific shape and profile). They said this gave it a smoother sound because the reflections back into the dome from the surround were significantly reduced vs traditional tweeter surrounds. If I remember correctly; it had two phase structures similar (NOT identical) to that on the newer "gold" tweeter (model TW025A28). I have yet to find a spec sheet or even an old photo; these were available in the late 1980's up through some time in the 1990's. I'll keep looking though...
The effects of felt on baffle have been investigated fairly rigorously, I've seen a few places but this is the only one I can find quickly in my notes:
David Ralph's Speaker Pages - Felt Effects on Baffle Diffraction
Felt Rings verses Felt Blocks for Baffle Diffraction Reduction
It is quite a thorough treatment of the subject! Too bad the felt looks so terrible, but I suspect there are ways using a fabric cutter & CNC or laser cutter to precisely machine some sort of creative felt inserts that would look more acceptable.
David Ralph's Speaker Pages - Felt Effects on Baffle Diffraction
Felt Rings verses Felt Blocks for Baffle Diffraction Reduction
It is quite a thorough treatment of the subject! Too bad the felt looks so terrible, but I suspect there are ways using a fabric cutter & CNC or laser cutter to precisely machine some sort of creative felt inserts that would look more acceptable.
Pair of JBL Titanium ARC Tweeters from LXE770 Speakers with Gaskits | eBay
YAY! see if this link opens; I couldn't post the image itself. This is the exact same tweeter, the DTi-01 by Audax but with a totally different faceplate. The original was just a regular round faceplate.
Dampers: Felt Defraction Ring for Tweeters
Madisound and I think also Meniscus have these "tweeter rings". Like I said; I cut one in half and placed this "semi-circle" on the top of the faceplate ABOVE the dome. This means the lower half of the faceplate would still contribute to the dispersion and diffraction somewhat. For this tweeter, the full circle caused an over-damp effect so the image actually became too "dull" (like placing a sock directly over the dome)...
McMaster-Carr
McMaster-Carr
McMaster Carr has 100% wool felt and composites; some with adhesive backing. I remember now I have used this before. I sometimes use cork sheets on the baffle board and then make a somewhat circular pattern all around the tweeter and midrange faceplate and frame with the felt adhered on top of the cork. This does improve imaging and focus; especially for near-field use as in monitors, etc.
There is a comparison chart of the different felt types that McMaster Carr stocks. I'm quite sure 100% lamb's wool is the very best; most papers say so and it shows also in the measurements...
About Selecting Wool Felt
Felt Selector Pack—Includes seven samples; one 1 3/4" × 1 3/8" piece of each of the following felts: F1, F3, F5, F7, F10, F13, and F26. Information about each felt is listed on the back side of the sample sheet. Select 9248K222.
Having posted what I did about the felt diffraction studies, I want to make clear that while it's academically interesting the effects of felt on the baffle and such, it's not something I would recommend spending any time on until the fundamentals are completely mastered and addressed in a given design. The fundamentals IMO being:
1. Learning to correctly perform measurements in-box that can be used for crossover simulation & design
2. Learning to use the measurements to get acoustic offset right for the listening position & axis
3. Learning to choose appropriate crossover frequencies & slopes to match directivity (as well as possible) between drivers through their overlap band, and to make sure drivers are not asked to work in ranges of high odd order distortion or major cone breakup
4. Learning to simulate driver layouts on a baffle, and compensate for baffle step and baffle diffraction effects
Obviously you could say felt is part of point 4, but felt is just *one* tool that can change baffle diffraction, not the only one, or even the first one to reach for.
It *is* an easy one to experiment with once the speaker is built, and IMO that is the time to look at it, as in oldspkrguy's example (if I understood correctly). Notice a diffraction problem in your measurements that wasn't expected from your baffle-optimization simulations? See what strategically placed felt can do.
I don't mean to patronize at all diyiggy - you may have all of these aspects very well in hand already, in which case have at it, and please forgive my presumption. I just realize that it's easy to get off on tangents and if one is fairly new, it's often hard to know what are the 'big rocks' to attend to first, and what are the 'small rocks' to address when the big ones are properly sorted.
1. Learning to correctly perform measurements in-box that can be used for crossover simulation & design
2. Learning to use the measurements to get acoustic offset right for the listening position & axis
3. Learning to choose appropriate crossover frequencies & slopes to match directivity (as well as possible) between drivers through their overlap band, and to make sure drivers are not asked to work in ranges of high odd order distortion or major cone breakup
4. Learning to simulate driver layouts on a baffle, and compensate for baffle step and baffle diffraction effects
Obviously you could say felt is part of point 4, but felt is just *one* tool that can change baffle diffraction, not the only one, or even the first one to reach for.
It *is* an easy one to experiment with once the speaker is built, and IMO that is the time to look at it, as in oldspkrguy's example (if I understood correctly). Notice a diffraction problem in your measurements that wasn't expected from your baffle-optimization simulations? See what strategically placed felt can do.
I don't mean to patronize at all diyiggy - you may have all of these aspects very well in hand already, in which case have at it, and please forgive my presumption. I just realize that it's easy to get off on tangents and if one is fairly new, it's often hard to know what are the 'big rocks' to attend to first, and what are the 'small rocks' to address when the big ones are properly sorted.
I read YEARS (probably decades ago) about these effects. The main point was while it is obviously desirable to have a wide dispersion; the down fall was the far off-axis reflections interfered with the "purity" of the signal because they were strong enough to be audible once reflected. The old ripples in a pond thing but once the ripples reach the shore; they can bounce back either in phase or out of phase or some random in-between phase and slightly delayed in time so they are "destructive" to the "pure" original; signal. This would have been from a paper magazine; maybe Audio, Speaker Builder, High Fidelity, Stereophile, TAS, or similar (I can't be sure but I read it in 2 or 3 different places). It was before I owned a PC anyway. Good topic for me to research today as it supposed to be stormy and rainy most of the day here.
Diffraction Doesn’t Have to Be a Problem | audioXpress
I just now discovered this. Worth a read for sure. More to be discovered later; still on 1st coffee of the morning...
I just now discovered this. Worth a read for sure. More to be discovered later; still on 1st coffee of the morning...
[Review/DIY] DIY tweeter felt
Not very technical but it does mention things like the faceplate, even mounting screws, etc.
Not very technical but it does mention things like the faceplate, even mounting screws, etc.
Understanding Cabinet Edge Diffraction
Anyone out there a paying member of AES??? The above mentions AES. When looking on the AES site; I see many papers that probably give this topic the best scrutiny but I am unwilling to sign up or pay for such knowledge.
Anyone out there a paying member of AES??? The above mentions AES. When looking on the AES site; I see many papers that probably give this topic the best scrutiny but I am unwilling to sign up or pay for such knowledge.
Btw, does anyone aware of a good link with choice for spare & refurbishment parts : dome with its voice coil to be glued on a plate, please ? (i.e. with the surround fabric to be glued after centering)
Did some of you liked the old paper cone tweeter, some of them with little mushrom dome ? Did you find them to have some qualities, but the vintage sound ?
Some of them are quite cheap todays ! Okay, the modern domes of that list are so cheap enough that it doesn't care but just to know, or at least in a find on the road old cabinets context !
MONACOR: HT-22/8
T-25 2-1/2" Paper Cone Tweeter 8 Ohm
Goldwood GT-25 3.5" Paper Cone Tweeter
The last is less than a buck, incredible... outlet I presume ! I still have one or two model on shelves somewhere, under the dust, lol !
Did some of you liked the old paper cone tweeter, some of them with little mushrom dome ? Did you find them to have some qualities, but the vintage sound ?
Some of them are quite cheap todays ! Okay, the modern domes of that list are so cheap enough that it doesn't care but just to know, or at least in a find on the road old cabinets context !
MONACOR: HT-22/8
T-25 2-1/2" Paper Cone Tweeter 8 Ohm
Goldwood GT-25 3.5" Paper Cone Tweeter
The last is less than a buck, incredible... outlet I presume ! I still have one or two model on shelves somewhere, under the dust, lol !
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Personally if I were to go down that cone tweeter route, I would be inclined to do a FAST type design, using instead a very good 2-3" full/wideband driver like the fountek fr88, SB65, a BMR, or the little Dynavox. There's a good review of a number of them here;
Timothy Feleppa's Pages: Speaker Measurements - Midrange/Fullrange Speakers 4" and smaller
which notes which are best suited for mid-tweeter duty and which are more traditional fullrange drivers. In the best instances, these can sound quite good, but IME never match the delicacy and articulation of a good dome, ribbon, or planar. I have used them in the past though, when I couldn't afford a *good* dome tweeter, or for a budget build where bass extension and quality was the top priority. For example; to a non-audiophile with a preference for electronic music and tendency to crank the volume, putting more money into getting lots clean output in the 30-400hz range is much more likely to impress than a more articulate top-end.
There's a fellow on here who was a big fan of paper cone tweeters, can't recall who but I'm sure if you start a thread he'd be all over it.
Timothy Feleppa's Pages: Speaker Measurements - Midrange/Fullrange Speakers 4" and smaller
which notes which are best suited for mid-tweeter duty and which are more traditional fullrange drivers. In the best instances, these can sound quite good, but IME never match the delicacy and articulation of a good dome, ribbon, or planar. I have used them in the past though, when I couldn't afford a *good* dome tweeter, or for a budget build where bass extension and quality was the top priority. For example; to a non-audiophile with a preference for electronic music and tendency to crank the volume, putting more money into getting lots clean output in the 30-400hz range is much more likely to impress than a more articulate top-end.
There's a fellow on here who was a big fan of paper cone tweeters, can't recall who but I'm sure if you start a thread he'd be all over it.