I don't know if this qualifies as an extreme basket trick but over the weekend I put some remainders of this stuff
Damping Foil 2552 Silver, 2 in x 36 yd 10.0 mil - Shop3M
on the frame and magnet assembly of my dayton ps 220ies which are on open baffles.
Two layers on the bottom side of each 'leg' of the frame, and a couple of layers on the outside of the magnet assembly.
What I found interesting is that I heard a strong difference on trumpets in a symphony orchestra: the rasp of the sound was suddenly much more convincing. But I would be hard pressed to identify any other difference in what I heard.
Damping Foil 2552 Silver, 2 in x 36 yd 10.0 mil - Shop3M
on the frame and magnet assembly of my dayton ps 220ies which are on open baffles.
Two layers on the bottom side of each 'leg' of the frame, and a couple of layers on the outside of the magnet assembly.
What I found interesting is that I heard a strong difference on trumpets in a symphony orchestra: the rasp of the sound was suddenly much more convincing. But I would be hard pressed to identify any other difference in what I heard.
I have just brought some Aucharm 8 inch drivers and noticed the expensive "luxury version" complete with alnico magnets has some crazy spherical deflector at the rear
http://www.aliexpress.com/item-img/...Magnet-Mixed-Paper-Cone-8ohm/32492939628.html
Is this possibly of practical value or something of a basket case����
A bit of work to some of the smaller IKEA Blanda bowls could probably simulate these, just wondering if it is worth my time?
http://www.aliexpress.com/item-img/...Magnet-Mixed-Paper-Cone-8ohm/32492939628.html
Is this possibly of practical value or something of a basket case����
A bit of work to some of the smaller IKEA Blanda bowls could probably simulate these, just wondering if it is worth my time?
All of these driver modifications may...or may not, improve the sound, and it's possible you may not hear any difference at all. While I'm not the leading authority of driver mods, I've certainly done "a lot" of them as have Bud Purvine, Dave D. (Planent10, both of whom I have known for many years and count as friends. If the driver is inexpensive and can be easily replaced then you're OK. On expensive drivers you may want to confine yourself to easily reversible mods.
Best Regards,
TerryO
Thanks Terry. To be honest, the difference was interesting, and at least I wasn't aware of it making things worse, but there was a degree of hassle in applying the stuff. I probably wouldn't bother again.
Not that I am an engineer, but I wonder if the constrained layer damping tape, makes more of a difference on flat surfaces.
Subsequently, I did try something which I think is more intersting in terms of the results. Its a vibration damping 'gel' sheet, apparently used for mounting vibration sensitive components in drones. I applied it on the basket 'arms', and on the magnet assembly. What I hear in general is more clarity pretty much everywhere, a bit like if someone had take a sock of the loudspeaker. If I had new drivers, I would redo that without hesitation. But because the speakers are open baffle, they look terrible from behind because they have little bits of green gel (its not painted on, it has the texture of a soft rubbery compound).
There is a Japanese product which I would really like to try (there is an ad showing them dropping an egg off a building onto a two inch thick pad and the egg not breaking). I understood that the material has been designed to be extremely lossy. Called 'alpha gel' I think (and I have no association to them at all).
I'm thinking of modifying my CSS EL70, primarily filling out the spaces in the back of the bezel, but also filling in the gap between the magnet and the frame as is suggested here in the thread.
However I'm not sure what material I should use. Blu-tack is easy to get here, but duct-seal seems more difficult (or maybe I'm just bad at translating it into Swedish). I found this which is some sort of material used for sealing sewage pipes and such. Description says it is a non-hardening synthetic rubber putty. What do you think?
I have googled to try and find out the density of blu-tack and the Unigum putty. Blu-tack seems to have ~80% higher density than the putty, so better for mass-loading?
However I'm not sure what material I should use. Blu-tack is easy to get here, but duct-seal seems more difficult (or maybe I'm just bad at translating it into Swedish). I found this which is some sort of material used for sealing sewage pipes and such. Description says it is a non-hardening synthetic rubber putty. What do you think?
I have googled to try and find out the density of blu-tack and the Unigum putty. Blu-tack seems to have ~80% higher density than the putty, so better for mass-loading?
The material used on the FE108eS is a latex damping paint used on boats to damp hull resonances. It is fiddly and you have to apply many thin coats to build it up.
Ductseal is easy and not messy, you need to apply a little bit at a time & push the ductseal into the cavities. The EL70eN you have should have a ring of this at the basket and magnet junction.
By all accounts Blu-tack should work in the place of ductal, but i have only ever been able to find Blu-tack clones and they don’t work.
dave
Ductseal is easy and not messy, you need to apply a little bit at a time & push the ductseal into the cavities. The EL70eN you have should have a ring of this at the basket and magnet junction.
By all accounts Blu-tack should work in the place of ductal, but i have only ever been able to find Blu-tack clones and they don’t work.
dave
Okay, this is what I was thinking of getting Glue Pads - UHU patafix, UHU patafix homedeco, UHU patafix PROPower, UHU fix
considering that this thread was started back in 2007 has any one reported or noticed any long term effects with using Ductseal for this type of mod?
i've noticed that over time and cold conditions causes ductseal to release a clear viscous fluid and turns the ductseal to a crumbly flaky state.
i don't know what it is or if it has any negative effects.
i've noticed that over time and cold conditions causes ductseal to release a clear viscous fluid and turns the ductseal to a crumbly flaky state.
i don't know what it is or if it has any negative effects.
I have been using Ideal ductseal since the late 70s and have been able to reuse stuff i have taken off of 25 year old woofers. Some of the other brands (not as much experience mind you) i was not as happy with. So, the Ideal brand in particular, seems quite stable.
dave
dave
From what it says it should work, but the only way you can be sure is to try it. It is a reversible mod.
dave
I bought the Patafix glue pads today and I just finished one driver. It took a lot more time than expected. One driver took around an hour to finish. I managed to get four strips of glue pads onto the driver, so around 40g in total. I can't say if I hear any difference (it's probably very subtle) but I can definitely feel a difference if I put my fingers on the bezel while playing music. The untreated driver rings a lot more than the treated one. I will do the second one and upload pictures after dinner.
This is what the driver looks like before/after treatment. In the first pictures you can see Dave's stuff in between the magnet and the driver frame.
Fiddly indeed! I wouldn't have made it without the help from my father and a local carpenter.
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That guy started out making furniture. Then he started making skis, and now he's making guitars as well. I think that angled cut would have been extremely difficult to do well with normal home-gamer equipment.
that's what I like to see - a messy shop
one of the best recent tools acquired at my own work was a slider with 8ft wide extension table , 10ft stroke and scoring blade - encroaches a lot of floorspace, but very useful
one of the best recent tools acquired at my own work was a slider with 8ft wide extension table , 10ft stroke and scoring blade - encroaches a lot of floorspace, but very useful
Even a baby sliding table is better than nothing. I have the no longer made Grizzly copy of an ancient Delta on my unisaw. Also having one right tilt and one left tilt t-saw is an asset when departing the 90 degree safety zone.
I tried a dynamat copy, sold as rain gutter repair tape, and it definitely reduced the ringing basket. I use plumbers' epoxy putty between the motor and basket because I'm impatient.
I tried a dynamat copy, sold as rain gutter repair tape, and it definitely reduced the ringing basket. I use plumbers' epoxy putty between the motor and basket because I'm impatient.
Delayed edit: there is no "safety zone" at a table saw or any other power tool. My bad.
ChrisB: don't you mean 3.048 meter stroke?
ChrisB: don't you mean 3.048 meter stroke?
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Interesting thread!
I see some doubt about ringing baskets, and as 'proof' I would recommend flipping the driver and mounting it with magnet on the outside in the cabinet and feel the vibration in basket/magnet with your fingers while feeding it various signals (pink noise/music/sine). I did this yesterday on some Vifa drivers with stamped frames, and found a resonance in the magnet to basket connection at about 300hz. Frequency would be higher on a std driver, these have extra magnets so that would lower the frequency due to added weight. This is the only issue I found, so I'm thinking I should reinforce the connection between magnet and basket.
I see some doubt about ringing baskets, and as 'proof' I would recommend flipping the driver and mounting it with magnet on the outside in the cabinet and feel the vibration in basket/magnet with your fingers while feeding it various signals (pink noise/music/sine). I did this yesterday on some Vifa drivers with stamped frames, and found a resonance in the magnet to basket connection at about 300hz. Frequency would be higher on a std driver, these have extra magnets so that would lower the frequency due to added weight. This is the only issue I found, so I'm thinking I should reinforce the connection between magnet and basket.
My belief is that the ringing is overshoot on transients, maybe a half cycle (if sine wave but transients are spikier) at the resonant frequencies of the various bits of the basket. Mostly the legs (one) and the frame to magnet zone (another one). Attaching the driver to the baffle damps most of the gross ringing one hears if suspending the speaker from a string and giving it a tap, but the subtle remnants are worth suppressing.
Frame to magnet area is the biggest problem on stamped baskets, and the putty is a gusset.
Frame to magnet area is the biggest problem on stamped baskets, and the putty is a gusset.
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