Teradacto, here's my 'first edition' of a 'how to' guide in making a Walsh to (hopefully) assist in that endeavour. I need to go back and edit/revise some details, but if your peruse it you'll have the gist of what's involved...at least, my approach to an earlier pair.
https://drive.google.com/file/d/0BzQ6s9CUyWnUNjVFck1vUFVFcDg/view?pli=1
If there's anything I'd add briefly here:
-A pair of speakers used for automotive applications are generally suitable. Don't go carving up a nice set of new ones for your first 'haveatit'. Mine weren't; even the current ones aren't, although their 'pedigree' (Chrysler/lInfinity) is better, they were 'freebies'...
-Put spacers into the voice coil gap to maintain alignment when gluing up the cone to the vc and later to the surround. I missed that little detail and it's really important to do. One of the four showed the result of Not doing that....fortunately, the 'fix' was a piece of (literally) 'bailing wire', but I can't recommend nor guarantee that would work again. They can be 'snatched out' with a long-nosed pliers or forceps later....
I can be PM'd if you've any questions on the process. It's a bit involved and requires a bit of 'set-up', but the result can be pretty fascinating. *G*
https://drive.google.com/file/d/0BzQ6s9CUyWnUNjVFck1vUFVFcDg/view?pli=1
If there's anything I'd add briefly here:
-A pair of speakers used for automotive applications are generally suitable. Don't go carving up a nice set of new ones for your first 'haveatit'. Mine weren't; even the current ones aren't, although their 'pedigree' (Chrysler/lInfinity) is better, they were 'freebies'...
-Put spacers into the voice coil gap to maintain alignment when gluing up the cone to the vc and later to the surround. I missed that little detail and it's really important to do. One of the four showed the result of Not doing that....fortunately, the 'fix' was a piece of (literally) 'bailing wire', but I can't recommend nor guarantee that would work again. They can be 'snatched out' with a long-nosed pliers or forceps later....
I can be PM'd if you've any questions on the process. It's a bit involved and requires a bit of 'set-up', but the result can be pretty fascinating. *G*
Oh, good, it isn't 'hanging'! Cool! *L* I hate when things do that to me, and I'd not be pleased to subject someone to that....
But, as pointed out, it could benefit from a 'update/revision'. And one should be warned that 'off the shelf' PVC parts for larger endeavours get pricey real quick, which is why I opted to make my own for the V.3's...not a project for a 'weekend warrior' IMHO. I've got a lot of tools and a commercial workspace at hand and my disposal, which makes for the improbable possible...
And then there's my mantra:
We, the Unwilling
Led by the Unknowing
Have been doing The Improbable
For so long
With so little
That today we will attempt
To do the Impossible
With Nothing.
(Seen on a t-shirt of a guy on a barstool next to me in NYC. Tried to talk him out of it...no go. It's stuck in my head for over 30 years now, and it's so appropo for so much in so many situations that it should be carved in marble Somewhere....*L*)
But, as pointed out, it could benefit from a 'update/revision'. And one should be warned that 'off the shelf' PVC parts for larger endeavours get pricey real quick, which is why I opted to make my own for the V.3's...not a project for a 'weekend warrior' IMHO. I've got a lot of tools and a commercial workspace at hand and my disposal, which makes for the improbable possible...
And then there's my mantra:
We, the Unwilling
Led by the Unknowing
Have been doing The Improbable
For so long
With so little
That today we will attempt
To do the Impossible
With Nothing.
(Seen on a t-shirt of a guy on a barstool next to me in NYC. Tried to talk him out of it...no go. It's stuck in my head for over 30 years now, and it's so appropo for so much in so many situations that it should be carved in marble Somewhere....*L*)
Tera, yeah, I could do it that way, but....ultimately I'd just disassemble the unit, cutting off the old surround. Then I'd spacer the voice coil (which I Should Have Done in the 1st place), reassemble and glue the cone to the new surround. That ought to cure it's ills.
I might tackle that after I build the V.4's. Clean up the V.3's (if I don't blow them up 1st...they weren't meant to last forever, they're just a test bed after all...) and perhaps gift someone with them. *L* Give my mongrels a good home....
We'll see how things transpire with the next iteration. They'll either work or they'll suck. But at some point I'll start swimming in speaker sets, and they don't stack real well....*G*
I might tackle that after I build the V.4's. Clean up the V.3's (if I don't blow them up 1st...they weren't meant to last forever, they're just a test bed after all...) and perhaps gift someone with them. *L* Give my mongrels a good home....
We'll see how things transpire with the next iteration. They'll either work or they'll suck. But at some point I'll start swimming in speaker sets, and they don't stack real well....*G*
Warning: May be habit-forming. *G*
Mmm, well, the HHR Walsh units use a large v.c. and magnet structure. But they're also driving a large cone which does have a typical frequency range for the typical listening range of music. That being said, the cone is Very Complex in it's composition; multiple materials with surface treatments and applied damping. My personal approach has been a single material for the cone, no treatments, and no damping materials as yet. I've kept to smaller drivers; starting with a 4" with 3/4" voice coils, current units (referred to as V.3, the ones on my YouTube vid) are 6.5" with 1" v.c., and the next V.4's are 6" with 1" v.c. This is to keep the complexity down for the DIY construction routines that I use.
I tried a pair of 12" with 1 1/2" v.c. and small magnets that didn't pan out...the cones are too heavy to drive properly. You might try that 8" with a paper cone (I used 5mil alum. on all my previous units) that's fairly 'stiff' as an initial experiment. The price is right for a DIY...most of my earlier units have been car audio drivers. I've also used 'low investment' speakers from Habitat, but they've not been terribly successful.
Smaller units won't have the bass frequencies that a larger cone can create, granted. But we've had discussions here about when the cone transits from radial radiation of the cone (which is generating the higher frequencies in an omni mode) to a pistonic motion (vertical motion, which generates the bass). There's a point in the diameter of the cone where this occurs; it's that point that I'm exploring, keeping the unit in 'radial mode' and using a sub to 'take up the slack' so to speak. The current units do create a certain amount of upper bass, even though the surrounds I've made limit the excursion of the cone to try to keep it functioning radially. But it's still pistonic to some degree which is unavoidable, due to the nature of a voice coil's design. This 'n that is the reason I'm more or less keeping the size of what I'm up to in the range of the German Physiks DDD drivers. Small is beautiful, for a number of reasons...
The price one pays for that limiting the normal movement of the voice coil is heat. The v.c. will cook itself if pushed too hard (high volumes) for too long. That's what happened to my first pair; you could feel them heat up through the back side of the magnet.
Larger units also will need larger surrounds and the structure to support it. My first two pairs (both 4") used PVC toilet flanges that were 'off the shelf', low cost, and reasonably easy to adapt. That made for a relatively easier 'build' and acceptable success. They Worked. It's nice when a first and second attempt yields that. *S* Inspires confidence to move forward, which has been my rationale.
All of the above being said....have at it. If you've got any questions, you can PM me or post here, I'll try to help.
Mmm, well, the HHR Walsh units use a large v.c. and magnet structure. But they're also driving a large cone which does have a typical frequency range for the typical listening range of music. That being said, the cone is Very Complex in it's composition; multiple materials with surface treatments and applied damping. My personal approach has been a single material for the cone, no treatments, and no damping materials as yet. I've kept to smaller drivers; starting with a 4" with 3/4" voice coils, current units (referred to as V.3, the ones on my YouTube vid) are 6.5" with 1" v.c., and the next V.4's are 6" with 1" v.c. This is to keep the complexity down for the DIY construction routines that I use.
I tried a pair of 12" with 1 1/2" v.c. and small magnets that didn't pan out...the cones are too heavy to drive properly. You might try that 8" with a paper cone (I used 5mil alum. on all my previous units) that's fairly 'stiff' as an initial experiment. The price is right for a DIY...most of my earlier units have been car audio drivers. I've also used 'low investment' speakers from Habitat, but they've not been terribly successful.
Smaller units won't have the bass frequencies that a larger cone can create, granted. But we've had discussions here about when the cone transits from radial radiation of the cone (which is generating the higher frequencies in an omni mode) to a pistonic motion (vertical motion, which generates the bass). There's a point in the diameter of the cone where this occurs; it's that point that I'm exploring, keeping the unit in 'radial mode' and using a sub to 'take up the slack' so to speak. The current units do create a certain amount of upper bass, even though the surrounds I've made limit the excursion of the cone to try to keep it functioning radially. But it's still pistonic to some degree which is unavoidable, due to the nature of a voice coil's design. This 'n that is the reason I'm more or less keeping the size of what I'm up to in the range of the German Physiks DDD drivers. Small is beautiful, for a number of reasons...
The price one pays for that limiting the normal movement of the voice coil is heat. The v.c. will cook itself if pushed too hard (high volumes) for too long. That's what happened to my first pair; you could feel them heat up through the back side of the magnet.
Larger units also will need larger surrounds and the structure to support it. My first two pairs (both 4") used PVC toilet flanges that were 'off the shelf', low cost, and reasonably easy to adapt. That made for a relatively easier 'build' and acceptable success. They Worked. It's nice when a first and second attempt yields that. *S* Inspires confidence to move forward, which has been my rationale.
All of the above being said....have at it. If you've got any questions, you can PM me or post here, I'll try to help.
Cone sizes were/are 75 degrees in angle typically. The V1's and V2's were both for 1" voice coils, 3" bottom diameter, and 4 3/4" tall. The V3's and the forthcoming V4's are 1" v.c.'s, 5" bottom, and 7" tall. 4" and 6" original speakers respectively.
Paper would be better, as vinyls and plastics in general don't work very well. I've been using 5mil lithographic aluminum since I've got a lot of it about, although I've been chided for it....too thick, too heavy. The lighter the cone, the better. Paper that's stiff without being too thick might be your best approach. You'll likely want something that has rigidity when rolled into a cone shape...something smooth surfaced, although that's just a best guess... File folder paper might be my choice, but if you've got something else or better, go for it.
The German Physiks cones I'm basically copying have titanium or carbon fibre cones, so that'll give you a sense of what you should consider re paper. The aluminum that I'm going to be using as well as the 5mil I have is 2mil 'full hardness aluminum foil'. Definitely not the supermarket variety, it's available at Graingers. It needs to be stiff; typical foils just can't cut it.
Here's a nifty website that'll help in creating accurate cones:
Cone and truncated cone
You just dial in the parameters and bingo...and some careful drawing and you're go to go. *S*
Use a good adhesive for the seam...you don't need your cone unraveling during Vivaldi, right?
Paper would be better, as vinyls and plastics in general don't work very well. I've been using 5mil lithographic aluminum since I've got a lot of it about, although I've been chided for it....too thick, too heavy. The lighter the cone, the better. Paper that's stiff without being too thick might be your best approach. You'll likely want something that has rigidity when rolled into a cone shape...something smooth surfaced, although that's just a best guess... File folder paper might be my choice, but if you've got something else or better, go for it.
The German Physiks cones I'm basically copying have titanium or carbon fibre cones, so that'll give you a sense of what you should consider re paper. The aluminum that I'm going to be using as well as the 5mil I have is 2mil 'full hardness aluminum foil'. Definitely not the supermarket variety, it's available at Graingers. It needs to be stiff; typical foils just can't cut it.
Here's a nifty website that'll help in creating accurate cones:
Cone and truncated cone
You just dial in the parameters and bingo...and some careful drawing and you're go to go. *S*
Use a good adhesive for the seam...you don't need your cone unraveling during Vivaldi, right?
If I may add my
... Paper would be better, I agree. Easy to work with, too.
Although, the 6 mil polypropylene 'drawing paper' I tested was among the best materials I tried.
Paper + plastic = self-damping, which is good.
Thickness does nothing accept add to the geometrical stiffness, which is good.
It's the density that subtracts. i.e.,...
High Density = lower wave velocity. Which is not good.
Thin materials that I've tried failed because they were just too flimsy (not stiff).
So, a thick (stiff) paper that is low-density (light) would IMO be ideal.
(Which proved out to be the case in practice).
Yeah, when it comes to stiffness---metal is paper on viagra...
But, the density is higher.
I like combining the two.
Metal on top.
Yeah, I'd noticed that. Makes sense...combine the best characteristics of both, minding the thickness and weight. 2mil on 1.5mil paper? 2mil on the polypro? Sounds like an interesting experiment...
Metal 'on top' = 'outside', right?
Meanwhile, setting up for the V4's...decided to have the parts cut for the surrounds and tweeter support cut for 4, but will assemble 2 with the revised cones. See if it sounds significant in some way before another pair....
Metal 'on top' = 'outside', right?
Meanwhile, setting up for the V4's...decided to have the parts cut for the surrounds and tweeter support cut for 4, but will assemble 2 with the revised cones. See if it sounds significant in some way before another pair....
'Rap that cone. (Repeat endlessly to an EDM beat...) *G*
And for *G*'s, hooked up the V2's for 'puter monitors. In this fashion I'll be +/- able to tell what eq at the 'puter is doing to the V3's without having to shuttle self quite as much. Also allows for some playing around with some Hegeman 'enhancements', if that's what they'll do...
Now all I need to do is hook up a sub in here. Spouse has asked for some speakers in her section of the building, so I guess I'll just have to make some more...
And for *G*'s, hooked up the V2's for 'puter monitors. In this fashion I'll be +/- able to tell what eq at the 'puter is doing to the V3's without having to shuttle self quite as much. Also allows for some playing around with some Hegeman 'enhancements', if that's what they'll do...
Now all I need to do is hook up a sub in here. Spouse has asked for some speakers in her section of the building, so I guess I'll just have to make some more...