Sanded them back down for hopefully the final time. I located the pilot holes that I drilled in the baffle pre-assembly. Then goy busy making sawdust. I messed up slightly and cut the tweeter recess a little over 1/16" too large. If that is my worst screwup on this project I'll be happy!
Now if you boys think you can behave.... I'll let ya have a peek of the test fit. Okay?.. okay
I do my builds backwards otherwise I end up listening to them for two years and don't want to finish em. Making em look good helps inspire to slog through the crossover designing stage (my least favorite part).
So this is my first time dealing with a midrange chamber. Thinking through how to fill it.
I've got some 1/2" felt I was thinking to line the chamber with. Then I found some leftover scraps of the 1.5" denim insulation I would put against the felt at the back of the chamber as a progressive damping. Probably 2 layers of that if I have enough. I used up the last of my polyfill already so I figured I'd just leave whatever is left of the chamber as an open airspace. Just trying to murder those back waves as much as possible. Would this be overkill and not helpful, or hurt more than help? Any additional suggestion?
Progressive fill of chamber from nearest cone to back of chamber with layers of increasingly dense materials containing long fibers as a suggestion - don't pack it tightly - let the wave penetrate the layers to full depth because they wont make it back to the cone. compressing the fill just shortens the depth of the chamber.
So possibly get another bag of polyfill. So it can go from polyfill, to denim insulation, to felt? Maybe nix the idea of lining the sides of whole chamber with the felt in that case?
I think I do have a bag of fiberglass insulation left. I know it has fallen out of fashion in the hobby, but last I heard it works better than polyfill. and it will be in a sealed enclosure anyway.
I usually line the midrange enclosure with felt because I have it. Then some denim insulation. Then maybe some polyfil - I have a huge box of polyfil from Joann's Fabrics. I don't A/B test different method, but this usually works well.
FWIW the Enduro-var does spray nicely. Maybe I should have just gone that way the whole time... Spray a few light coats in quick succession to get some thickness buildup, give it a day to dry and sand it down. Then mask off again and repeat. Probably after three rounds it would have been done and had just as many coats. Oah well.
This should keep me fizzin long enough to push through the crossover design!
The tweeter screws are so close to the cutout it is already trying to blow the screw holes out. Probably remove once to solder on some extended leads and try to not remove them again.
Making back gaskets for the TC9s. I just use the ~1/16" thick foam sheet you can get at Michaels (hobby store). It is found over in the kids section on a big rack of multiple colors of the stuff, $.99 for a black 12x18" sheet. If you use one of the thin pencil xacto knives it will actually fit in a drawing compass to make more accurate circle cuts. Or just use a nice sharp pencil and it will make a good enough line to easily follow with the knife by hand. For bonus points use a leather punch tool (can find at Menards) to punch out screw holes.
@jr@mac said:
I really wish I possessed the woodworking skills to do veneer. These look great and I am sure you will do the drivers justice.
Veneering with paper backed stuff really is simple on flat surfaces. Especially with PSA now that I have had this experience.
I gleaned most of the PSA-specific application info from here:
He used a scraper that is basically a plastic carpet tuck too. Though for this PSA application I started with a "high pressure" J-roller that I got from a woodworking store and went back over it with the scraper to be sure adequate pressure was applied. Normally J-rollers are a no-no since they are difficult to apply enough pressure. That is why they use the scraper, can concentrate that force on a tiny line to smash the cement together.
You can trim it with a router, though it isn't a necessity. Trim the loose ends close to the edge with whatever is available (scissors would probably even work) then you can use one of these razor trim tools to finish it off and move to the next side. I found the less overhang you have after that first trim, the easier that razor tool is to use. For angles other than 90deg probably just have to trim it close and work the remaining lip down with sand paper on a block of wood.
Up to this point I wouldn't call this "woodworking", until you get to finishes.
I don't like to get too fancy with finishes. Most of the time I just use a clear and let the wood do the talking. I still want to try shellac. Should be less odor than oil based stuff since it is alcohol based and simple wipe on application with quick follow up coats. You can even get it in premixed cans. Since it doesn't build up much of a coating sanding should be minimal.
Jump to
3:30-7:50 (Canned stuff)
13:00-end (Application)
Lol you say that as if I'm not right there with ya. I'm doing all this outside on the deck with basic power tools. The facet cuts you do are very intimidating for me. Not sure if I'd ever try that. Block sanding is really all it takes (don't round the edges with the paper) and is way easier on the hands than regular hand sanding. Perfectly flat is a myth to me. You just get it as close as you can and the more matte the finish the more it hides any evils. I pretty much will not try a gloss because of that. Paint I find less forgiving in some ways because wood grain can visually break up an uneven surface, making it harder to detect than a completely uniform color.
In the end, I think you'd be surprised how little precision is really required.
Now if ya just don't wanna. Then ok I'll stop bothering you about it lol.
After j rolling I use a piece of wood as the scraper. Usually I have the identical species of wood, if not I use maple as it doesn't have any pigments that might transfer. Just use the 90* edge to burnish the veneer down.
@hifiside said:
I have a whole YouTube video on this. Flat! Flat! Flat!
Your work is on a whole other level than what I'm willing to reach for. So I allow myself to cut more corners in an effort to keep it from becoming drudgery.
Flat and square are two totally different things. I can usually manage the flat part, but square...I'm happy if it sits level and doesn't look like it's leaning.
@Steve_Lee said:
I am not at all skeptical of the elliptical - just making good natured fun of your fixation of all things that are not eggzakly egg shaped, Sir.
In the mid cup I've got 1" of felt, ~3" deep roll (gently rolled) denim insulation, and about a softball size hunk of polyfill that ended up very lightly compressed by the magnet.
Anything I should look back into before proceeding?
Don't think I've had tweeters this closely matched before on impedance. Looks like that 4k ringing is probably still there that Zaph measured on the older part numbers.
Comments
Things are heating up!
Sanded them back down for hopefully the final time. I located the pilot holes that I drilled in the baffle pre-assembly. Then goy busy making sawdust. I messed up slightly and cut the tweeter recess a little over 1/16" too large. If that is my worst screwup on this project I'll be happy!
Now if you boys think you can behave.... I'll let ya have a peek of the test fit. Okay?.. okay
Those look Great Andrew!
I really like the rounded veneer.
Just hope my crossoverin' skills can keep up.
I do my builds backwards otherwise I end up listening to them for two years and don't want to finish em. Making em look good helps inspire to slog through the crossover designing stage (my least favorite part).
So this is my first time dealing with a midrange chamber. Thinking through how to fill it.
I've got some 1/2" felt I was thinking to line the chamber with. Then I found some leftover scraps of the 1.5" denim insulation I would put against the felt at the back of the chamber as a progressive damping. Probably 2 layers of that if I have enough. I used up the last of my polyfill already so I figured I'd just leave whatever is left of the chamber as an open airspace. Just trying to murder those back waves as much as possible. Would this be overkill and not helpful, or hurt more than help? Any additional suggestion?
Progressive fill of chamber from nearest cone to back of chamber with layers of increasingly dense materials containing long fibers as a suggestion - don't pack it tightly - let the wave penetrate the layers to full depth because they wont make it back to the cone. compressing the fill just shortens the depth of the chamber.
Just a thought. Let us know what you find.
Great project execution, Drew.
So possibly get another bag of polyfill. So it can go from polyfill, to denim insulation, to felt? Maybe nix the idea of lining the sides of whole chamber with the felt in that case?
Line the front nearest cone with felt. Layer the rest as you suggest.
I think I do have a bag of fiberglass insulation left. I know it has fallen out of fashion in the hobby, but last I heard it works better than polyfill. and it will be in a sealed enclosure anyway.
Use it under a light layer of poly to keep its fine broken fibers filtered from the voice coil . . . ???
I usually line the midrange enclosure with felt because I have it. Then some denim insulation. Then maybe some polyfil - I have a huge box of polyfil from Joann's Fabrics. I don't A/B test different method, but this usually works well.
FWIW the Enduro-var does spray nicely. Maybe I should have just gone that way the whole time... Spray a few light coats in quick succession to get some thickness buildup, give it a day to dry and sand it down. Then mask off again and repeat. Probably after three rounds it would have been done and had just as many coats. Oah well.
This should keep me fizzin long enough to push through the crossover design!
The tweeter screws are so close to the cutout it is already trying to blow the screw holes out. Probably remove once to solder on some extended leads and try to not remove them again.
Making back gaskets for the TC9s. I just use the ~1/16" thick foam sheet you can get at Michaels (hobby store). It is found over in the kids section on a big rack of multiple colors of the stuff, $.99 for a black 12x18" sheet. If you use one of the thin pencil xacto knives it will actually fit in a drawing compass to make more accurate circle cuts. Or just use a nice sharp pencil and it will make a good enough line to easily follow with the knife by hand. For bonus points use a leather punch tool (can find at Menards) to punch out screw holes.
Those are some darn nice looking speakers!
Ditto! Nice units🤘🏼
I really wish I possessed the woodworking skills to do veneer. These look great and I am sure you will do the drivers justice.
Veneering with paper backed stuff really is simple on flat surfaces. Especially with PSA now that I have had this experience.
I gleaned most of the PSA-specific application info from here:
He used a scraper that is basically a plastic carpet tuck too. Though for this PSA application I started with a "high pressure" J-roller that I got from a woodworking store and went back over it with the scraper to be sure adequate pressure was applied. Normally J-rollers are a no-no since they are difficult to apply enough pressure. That is why they use the scraper, can concentrate that force on a tiny line to smash the cement together.
https://www.menards.com/main/flooring-rugs/carpet/carpet-installation-maintenance/roberts-reg-ez-tuck-carpet-tucker/10-522-4/p-1444451684160-c-6538.htm?exp=false
You can trim it with a router, though it isn't a necessity. Trim the loose ends close to the edge with whatever is available (scissors would probably even work) then you can use one of these razor trim tools to finish it off and move to the next side. I found the less overhang you have after that first trim, the easier that razor tool is to use. For angles other than 90deg probably just have to trim it close and work the remaining lip down with sand paper on a block of wood.
https://www.menards.com/main/kitchen/cabinet-organization-accessories/veneer-edge-banding/pureedge-trade-edge-trimmer/eitrimmerpe/p-3289655538077782-c-3607.htm?exp=false
Up to this point I wouldn't call this "woodworking", until you get to finishes.
I don't like to get too fancy with finishes. Most of the time I just use a clear and let the wood do the talking. I still want to try shellac. Should be less odor than oil based stuff since it is alcohol based and simple wipe on application with quick follow up coats. You can even get it in premixed cans. Since it doesn't build up much of a coating sanding should be minimal.
Jump to
3:30-7:50 (Canned stuff)
13:00-end (Application)
Just gotta have the gumption to give it a shot.
I can barely build a box, much less have it composed of flat surfaces. Let's just say 60 grit is my best friend 😊
Lol you say that as if I'm not right there with ya. I'm doing all this outside on the deck with basic power tools. The facet cuts you do are very intimidating for me. Not sure if I'd ever try that. Block sanding is really all it takes (don't round the edges with the paper) and is way easier on the hands than regular hand sanding. Perfectly flat is a myth to me. You just get it as close as you can and the more matte the finish the more it hides any evils. I pretty much will not try a gloss because of that. Paint I find less forgiving in some ways because wood grain can visually break up an uneven surface, making it harder to detect than a completely uniform color.
In the end, I think you'd be surprised how little precision is really required.
Now if ya just don't wanna. Then ok I'll stop bothering you about it lol.
After j rolling I use a piece of wood as the scraper. Usually I have the identical species of wood, if not I use maple as it doesn't have any pigments that might transfer. Just use the 90* edge to burnish the veneer down.
I have a whole YouTube video on this. Flat! Flat! Flat!
Your work is on a whole other level than what I'm willing to reach for. So I allow myself to cut more corners in an effort to keep it from becoming drudgery.
Flat and square are two totally different things. I can usually manage the flat part, but square...I'm happy if it sits level and doesn't look like it's leaning.
How about Egg shaped speakers? Problems solved.
Do you also drive a Ford automobile because of the logo?
I thought you were going to use the black side as the baffle side. Silly me.
I get it. Your skepticism is understandable. I would be too.
I am not at all skeptical of the elliptical - just making good natured fun of your fixation of all things that are eggzakly egg shaped, Sir.
Just egging you-on . . .
Settle down, Steve.
In the mid cup I've got 1" of felt, ~3" deep roll (gently rolled) denim insulation, and about a softball size hunk of polyfill that ended up very lightly compressed by the magnet.
Anything I should look back into before proceeding?
Don't think I've had tweeters this closely matched before on impedance. Looks like that 4k ringing is probably still there that Zaph measured on the older part numbers.