Dave I've been shopping; I found some self adhesive felt pads tha will(( I think )) work in combination, the woofers have a big dimple thats 25 X 75mm, got some harder felt pads 13 X 67 to stop ringing and some much softer thicker felt to stop reflection a little bit.
the two in combination should work.
Also got a couple of chipboard panels 188 X 450 to add structural stiffness to the baffles ( only 12mm thick ) so baffles will be my almost standard of a sandwich MDF- chipboard- MDF with a thickness between 25 and 40mm depending on how I feel and my ability to lift them when finished.
Next step finding the filler powder for the epoxy, nobody on this side of town has any in stock, not even powdered lime for line marking so I have to let my fingers do the walking some more
the two in combination should work.
Also got a couple of chipboard panels 188 X 450 to add structural stiffness to the baffles ( only 12mm thick ) so baffles will be my almost standard of a sandwich MDF- chipboard- MDF with a thickness between 25 and 40mm depending on how I feel and my ability to lift them when finished.
Next step finding the filler powder for the epoxy, nobody on this side of town has any in stock, not even powdered lime for line marking so I have to let my fingers do the walking some more
Dave it's international tradethat keeps the world turning ( Ihope )
the combination actually seems to work, I'm glad as I'm basically lazy.
Still waiting on supplies if filler for the epoxy, if I wa building boats everyone knows how to help me but I have West Systems technical staff stumped on audio related properties, it's nice to know the experts don't always know everything.
Cheeers
Ted
the combination actually seems to work, I'm glad as I'm basically lazy.
Still waiting on supplies if filler for the epoxy, if I wa building boats everyone knows how to help me but I have West Systems technical staff stumped on audio related properties, it's nice to know the experts don't always know everything.
Cheeers
Ted
Hey Ted, what about talc for filler for the epoxy? You might even get the non-aromatic kind. Otherwise, SWMBO might even like the smell of your speakers, too!
A generic brand is pretty cheap, and as you know, they do use it in some speaker cones as a lossy filler.
Stuey
A generic brand is pretty cheap, and as you know, they do use it in some speaker cones as a lossy filler.
Stuey
Stuey, thats a good idea, cheap and readily avaliable, would work as well as powdered chalk which has also been reccomended.
I'll probably use a mix of Aluminium or stainless steel powder and the talc for its anisotropic properties, just enough to stop it from running or slumping.
I've done the spoke of the woofers with the felt, I'd post a picture but black on black with flash?? I really don't think it is going to have much effect on woofers more a midrange tweak, not as effective at stopping the basket ringing as I'd hoped.
Tomorrow I will mix up some goop and start on the back of the driver.
i'm going to concentrate on the area around the magnet where it connects to the basket frame, will post photos as I work, only 8 drivers to treat should occupy my morning.
I'll probably use a mix of Aluminium or stainless steel powder and the talc for its anisotropic properties, just enough to stop it from running or slumping.
I've done the spoke of the woofers with the felt, I'd post a picture but black on black with flash?? I really don't think it is going to have much effect on woofers more a midrange tweak, not as effective at stopping the basket ringing as I'd hoped.
Tomorrow I will mix up some goop and start on the back of the driver.
i'm going to concentrate on the area around the magnet where it connects to the basket frame, will post photos as I work, only 8 drivers to treat should occupy my morning.
Wow!
I have just finished doing the felt on the insides of the spokes of the woofers.
No improvement in the bass, did not expect any, but the top end of these is now listenable, old time valve radio sound.
Definitely worth doing on my Ratshack drivers, when this is done I think I'll pull the 40-1028's out of the boxes and do the same for them also their 8inch little siblings (( wish I could find more of these; perhaps RS's most underrated driver because of the way they were sold as Sub-woofers when they are actually a mid-range))
Still waiting on reply and information from West Systems, but if I don't hear anything in a couple of days I'm going to use Stuey's suggestion and use talc mixed with the stainless filler to faid the magnet gap and stiffen the basket
I have just finished doing the felt on the insides of the spokes of the woofers.
No improvement in the bass, did not expect any, but the top end of these is now listenable, old time valve radio sound.
Definitely worth doing on my Ratshack drivers, when this is done I think I'll pull the 40-1028's out of the boxes and do the same for them also their 8inch little siblings (( wish I could find more of these; perhaps RS's most underrated driver because of the way they were sold as Sub-woofers when they are actually a mid-range))
Still waiting on reply and information from West Systems, but if I don't hear anything in a couple of days I'm going to use Stuey's suggestion and use talc mixed with the stainless filler to faid the magnet gap and stiffen the basket
Simon I took a couple of oix but black on black with flash--.. you cannot see details at all
http://www.masterdistributors.com.a...ter Distributors Product Catalogue_Madico.pdf
You can see the whole product range here.
This is going to take quite a while to finish, I'm guessing that 2 or 3 other smallish speakers will be finished before these big ones.
One of the problems is going to be moving the finished baffles, just moving the sheets of MDF on their own is hard work
http://www.masterdistributors.com.a...ter Distributors Product Catalogue_Madico.pdf
You can see the whole product range here.
This is going to take quite a while to finish, I'm guessing that 2 or 3 other smallish speakers will be finished before these big ones.
One of the problems is going to be moving the finished baffles, just moving the sheets of MDF on their own is hard work
Thanks for the PDF, the felt looks great. Isn't it amazing how so many of those floor protector products could have a hi-fi use!?
Simon
Simon
This 3-way has been put on the backburner whilst I finish a couple of cheapies and work on some complementary subs; but; I have been researching P13 XOs and only one of the publishedschemes uses a zobel on the Vifas.
The XO schematic in the Weems & Koonce Great sound &stereo speaker manual// project 6// uses a obel network on the mid-range, this is the only instance I can find of a designer using this conjugate on these drivers.
So the question; will I need it to get the best performance from tjese little woofers as a midrange.
As I am using 2 in MTM I don't think I will need much; if any, attenuation on the tweeterand I will be taking Andy's advice( other also ) and be crossing around 2500 (+/- 250)
I tried a test baffle using the probable final spacing ( that is as close together as possible ) and a single cap on the tweeter and it wasn't perfect.
The XO schematic in the Weems & Koonce Great sound &stereo speaker manual// project 6// uses a obel network on the mid-range, this is the only instance I can find of a designer using this conjugate on these drivers.
So the question; will I need it to get the best performance from tjese little woofers as a midrange.
As I am using 2 in MTM I don't think I will need much; if any, attenuation on the tweeterand I will be taking Andy's advice( other also ) and be crossing around 2500 (+/- 250)
I tried a test baffle using the probable final spacing ( that is as close together as possible ) and a single cap on the tweeter and it wasn't perfect.
I have been doing lots more reading, especially Lynn Olsns "Ariel" pages : thanks Lynn; 😀 ;and all of the designs rated as the best sounding use some sort of impedance manipulation.
Re-reading the pages on the Ariel, ha anyone had experience or can point me to information on modifying the D-27 to lower the resonance even further?? I have read lots but nothing specific to the Vifa D-27, being OB the pressure on the thin plastic chamber at the rear really isn't going to be a problem, but if I'm going to do this properly then all the small improvements should add up.
I will be using better qualty capacitors in the XO for this unit but haven't ordered them yet, I'm still playing with Jaycars yellow generic polypropylene caps.
Re the "Ariel" what purpose does the small aircore inductor have in the impedance stabilization conjugate??
I have used tweeter offset in my MTM layout for a long time and of course these will be made mirror image, L & R.
Re-reading the pages on the Ariel, ha anyone had experience or can point me to information on modifying the D-27 to lower the resonance even further?? I have read lots but nothing specific to the Vifa D-27, being OB the pressure on the thin plastic chamber at the rear really isn't going to be a problem, but if I'm going to do this properly then all the small improvements should add up.
I will be using better qualty capacitors in the XO for this unit but haven't ordered them yet, I'm still playing with Jaycars yellow generic polypropylene caps.
Re the "Ariel" what purpose does the small aircore inductor have in the impedance stabilization conjugate??
I have used tweeter offset in my MTM layout for a long time and of course these will be made mirror image, L & R.
Moondog55 said:
I would recommend the Jantzen caps and coils from SpeakerBug, (I'm at Uni at the moment so I don't have the link, email me at home if you need it.)
ad some clay to the woofer and
and sum clay to the woofers and you will only need two of them per side and tune them in their on seperate cabinet, use the mtm design for the mid range through high and focus for the flattest frequency from 200 to 8000 range I believe this is where the human ear is most sensitive to hearing I may be wrong. and find midrange with a very low Qts.
and sum clay to the woofers and you will only need two of them per side and tune them in their on seperate cabinet, use the mtm design for the mid range through high and focus for the flattest frequency from 200 to 8000 range I believe this is where the human ear is most sensitive to hearing I may be wrong. and find midrange with a very low Qts.
Thanks Andy & Pano, I was definitely going to use the Jantzen caps for the finished product, that site was bookmarked as soon as Andy posted it.
Mcmahon48, I'm actually using epoxy as the basket damping method, I'm going to stay with 4 woofers as changing the design now will attract negative WAF, extremely negative, I have to build it as approved by "SWMBO"
Mcmahon48, I'm actually using epoxy as the basket damping method, I'm going to stay with 4 woofers as changing the design now will attract negative WAF, extremely negative, I have to build it as approved by "SWMBO"
When paying $30- for a cap whats $3- for a resistor??
General rule of thumb I was given when I started this hobby ( addiction/ obsession) was 1/3 drivers ; 1/3 box ; 1/3 XO , look at how much I'm saving by not having a box !! ( subwoofers don't count )
General rule of thumb I was given when I started this hobby ( addiction/ obsession) was 1/3 drivers ; 1/3 box ; 1/3 XO , look at how much I'm saving by not having a box !! ( subwoofers don't count )
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