Hi GM, I noticed your reference to Cohen. Would that be Abraham? I have his "Hi-Fi Loudspeakers and Enclosures" A great reference. The covers are falling off. I have an idea though. I'll check out the 2nd hand book shops. I once saw a book that had black hard covers, and gold leaf titled "Old Testament" and rebind Cohen's words of wisdom. LOL
Once Bob gets away from his keyboard and cuts those baffles he could kick of a new thread "Restoring Toobs"
Cheers,
Geoff
Once Bob gets away from his keyboard and cuts those baffles he could kick of a new thread "Restoring Toobs"
Cheers,
Geoff
Speaking of cutting, Geoff, do you (or anyone else) have any tips on a cutter or technique for making a nice, round hole in the sheet plywood?
I've never had to produce a nice hole that large before. Is the thickness of the ply (say 3/4 versus 1/2 inch) a big variable to consider? I realize MDF is much more dense than ply, so that may make that choice easy.
I've never had to produce a nice hole that large before. Is the thickness of the ply (say 3/4 versus 1/2 inch) a big variable to consider? I realize MDF is much more dense than ply, so that may make that choice easy.
If you're mounting the speakers on the front of the baffle, just draw a circle of the appropriate diameter and free hand it with a jig saw. You're steady enough to be within a 1/16 of an inch. Any deviations from the line are going to be covered by the rim of the speaker, and can tolerate much more than 1/16 of an inch 
. Been there, done that .
Tom.
. Been there, done that .Tom.
Bob, as the others say, jig saw.
I draw 2 circles, one for the hole, and one for the PCD of the mounting bolts. Drill the mounting holes, then cut the circle. Not so critical with ply or mdf, but chipboard is fragile if the circle gets to close to the mounting holes.
Just take your time with the big circle. Mount the driver from behind, and if you can, chamfer the circle, leaving enough timber near the mounting holes. Let us know what they sound like.
Geoff
I draw 2 circles, one for the hole, and one for the PCD of the mounting bolts. Drill the mounting holes, then cut the circle. Not so critical with ply or mdf, but chipboard is fragile if the circle gets to close to the mounting holes.
Just take your time with the big circle. Mount the driver from behind, and if you can, chamfer the circle, leaving enough timber near the mounting holes. Let us know what they sound like.
Geoff
I just read this thread today and it is interesting to me. A couple months ago a friend gave me the "guts" from an old Magnavox console. There is a vertical mount tubed reciever, 2 15" drivers with small magnets, that were firing out of the sides of the console and 2 mid-hf horns and drivers ( small driver, both horn and driver painted orange), and Xovers. Everything look to be in good condition, but I don`t know what to do with these. Anybody in the Chicago area, who reads this forum, would be welcome to have them if picked locally. I don`t have a digital camera or I would post a pic of the stuff. If you`re interested let me know.
Greets!
I use to play at racing over your way back when it was 'God's Country'. Good to know there's another one of 'us' ~locally, we're few and far between AFAIK, with only a few others scattered from Tyrone to around the corner from me coming to mind at the moment. When we had the few Atlanta DIY Meets, most of the relatively few 'FR' folks that attended were well away from metro Atlanta, mostly from Tn. and S.C.. Small cone/dome two ways rule around here, so the vast majority of local DIYers hang over on the MAD and PE boards.
Yep, my hard bound 1st edition 'bit the dust' about the time the 2nd edition went to paperback, which is now held together with 3" wide book binding tape and mass quantities of PVA glue. As far as it goes, it's a timeless reference for the DIYer, as is Badmaieff's/Davis's 'How To Build Speaker Enclosures', especially for folks who are rooted in tube era systems.
GM
Smokehouse Bob said:
I use to play at racing over your way back when it was 'God's Country'. Good to know there's another one of 'us' ~locally, we're few and far between AFAIK, with only a few others scattered from Tyrone to around the corner from me coming to mind at the moment. When we had the few Atlanta DIY Meets, most of the relatively few 'FR' folks that attended were well away from metro Atlanta, mostly from Tn. and S.C.. Small cone/dome two ways rule around here, so the vast majority of local DIYers hang over on the MAD and PE boards.
Geoff H said:
Yep, my hard bound 1st edition 'bit the dust' about the time the 2nd edition went to paperback, which is now held together with 3" wide book binding tape and mass quantities of PVA glue. As far as it goes, it's a timeless reference for the DIYer, as is Badmaieff's/Davis's 'How To Build Speaker Enclosures', especially for folks who are rooted in tube era systems.
GM
Geoff H said:
Greets!
Ditto, I was about half-way through my speaker building 'career' before I acquired any power cutting tools and was ~done before I was given a router kit. Even then, by that time I was getting a neighbor to fly cut the driver cutouts on his big drill press, so have yet to use it for this app. FWIW, here's an example of my freehand jigsaw work from the late '60s, with all the other cutting on these ~20 ft^3 'subs' done with a handsaw in an apartment parking lot, so don't have any sympathy for the folks that whine about not being able to DIY because they don't have the space and/or table saw and/or router and/or jig, ad nauseum............
WRT chamfering, not having a router and in my need to save time where practical, I lined the cutout with felt and added a felt ring around the perimeter to mimic it, and when the driver was mounted from the front, a large/coarse half round 'b-a-s-t-a-r-d' file made short work of a small driver's cutout backside to allow it to 'breathe'/rapidly decay any HF standing waves. Not nearly as pretty as when a router/jig is used, but then I really don't care what the hidden parts look like and in theory my uneven 'hand-job' is technically superior due to its randomness.
As always though, YMMV.
GM
Attachments
Very nice GM. I have my basic woodworking tools (including a nice Craftsman from the 50s), so cutting, routing, sanding, etc. won't be the problem. I just want to have a reasonably "round" cut with less slop. With patience and an "appropriate-toothed" jigsaw it will work.
Another console came my way last week, but drivers from it don't appear to be alnico and they don't have the whizzer. They were used with a 6BQ5 PP amp.
Another console came my way last week, but drivers from it don't appear to be alnico and they don't have the whizzer. They were used with a 6BQ5 PP amp.
Nice cut-out GM. I seem to be happier working with metal than timber or MDF, and also impatient. I'll also conjure up excuses for something that may not be up to the standards of some of the fine furniture makers on these pages.
"and in theory my uneven 'hand-job' is technically superior due to its randomness."
If that theory is correct, the corner cabs my Wharfedales are in, are better than yours. But they were just an experiment, which worked.
There's a pic in the widerange thread. They have a bit of baffle radiation I want to address before cleaning up the hole.
The flycutter in a mill is the way for a perfect hole. I have mounted a jig-saw upside down on a foldup vice type workbench. A couple of small holes on the moving part for an arbour to drop in. Did a 6" circle fine once i got the offset right.
Bob, how come you get all the good old stuff? Don't discount the speakers. They could be pot type, or W (IMHO the best) The 6BQ5 is my favourite hand warmer. A bit more power than the 6V6, and lower distortion. I am considering building a nice big chasis with a bank of 8 in a row with 4 transformers behind them, and 4 12AX7s in front.
If you need any data on the old amps, I still have my 1964 edition of Miniwatt Tech data.
Take care all.
Geoff
"and in theory my uneven 'hand-job' is technically superior due to its randomness."
If that theory is correct, the corner cabs my Wharfedales are in, are better than yours. But they were just an experiment, which worked.
There's a pic in the widerange thread. They have a bit of baffle radiation I want to address before cleaning up the hole.
The flycutter in a mill is the way for a perfect hole. I have mounted a jig-saw upside down on a foldup vice type workbench. A couple of small holes on the moving part for an arbour to drop in. Did a 6" circle fine once i got the offset right.
Bob, how come you get all the good old stuff? Don't discount the speakers. They could be pot type, or W (IMHO the best) The 6BQ5 is my favourite hand warmer. A bit more power than the 6V6, and lower distortion. I am considering building a nice big chasis with a bank of 8 in a row with 4 transformers behind them, and 4 12AX7s in front.
If you need any data on the old amps, I still have my 1964 edition of Miniwatt Tech data.
Take care all.
Geoff
huh huh . .he said HAND JOB
but seriously:
I too am IN LOVE with the old console fullrangers; I (luckily) have a gargae to play in, so I've got some big 3X4 OB panels mounted towards the corners. I made them with square openings, about 16 inches square, so I can swap in different drivers at will.
Those RCA's look REAL NICE . . . I'm sure they'll sound great once mounted and positioned optimally. I've found the little Parts express .25 Onkyo tweeters to a pretty good job of filling on the highs on some of those console drivers . . . you can even co-axial mount them if your a little creative
I've got all sorts of console drivers in the 'stable' ; Magnavox, RCA, Zenith . . . my current favorites are some Zenith branded Fisher 15's with some Jensen RP103's to fill in the highs.
Latests experiments will be concerning phase plugs. Using varying diameter wood and styrafoam spheres ala ultra-fi Lowthers' to play with the beaming effects . . . .
HAVE A BLAST WITH THOSE !
but seriously:
I too am IN LOVE with the old console fullrangers; I (luckily) have a gargae to play in, so I've got some big 3X4 OB panels mounted towards the corners. I made them with square openings, about 16 inches square, so I can swap in different drivers at will.
Those RCA's look REAL NICE . . . I'm sure they'll sound great once mounted and positioned optimally. I've found the little Parts express .25 Onkyo tweeters to a pretty good job of filling on the highs on some of those console drivers . . . you can even co-axial mount them if your a little creative
I've got all sorts of console drivers in the 'stable' ; Magnavox, RCA, Zenith . . . my current favorites are some Zenith branded Fisher 15's with some Jensen RP103's to fill in the highs.
Latests experiments will be concerning phase plugs. Using varying diameter wood and styrafoam spheres ala ultra-fi Lowthers' to play with the beaming effects . . . .
HAVE A BLAST WITH THOSE !
Nothin wrong with that. The gentleman that modded my Wharfies had a large baffle with about 6 adaptor plates.
Anything that came in got screwed to an adaptor, after the basic bench test. That was 1/2 a watt of voice off the air, if didn't like what he heard, it went back to the supplier, or if modding gave him a good clue as to what was needed.
Geoff
Anything that came in got screwed to an adaptor, after the basic bench test. That was 1/2 a watt of voice off the air, if didn't like what he heard, it went back to the supplier, or if modding gave him a good clue as to what was needed.
Geoff
exactly
I have yet to do any solid measurements using my test baffles - its all by ear - but it definitely makes it easy to see what I like.
I have yet to meet a console driver I didn't like - it seems to be just a matter of how high, or low they go. I tend to like the 'all paper' drivers - paper cone, paper surround. they sound a little 'faster' to me.
I REALLY like a pair of little 10 " GE console drivers scored years ago.
I have yet to do any solid measurements using my test baffles - its all by ear - but it definitely makes it easy to see what I like.
I have yet to meet a console driver I didn't like - it seems to be just a matter of how high, or low they go. I tend to like the 'all paper' drivers - paper cone, paper surround. they sound a little 'faster' to me.
I REALLY like a pair of little 10 " GE console drivers scored years ago.
I don't worry about meter deflections either. The ear-ole is what counts. What makes those old drivers good, I think, was that more effort went into them. With only a handful of watts, the easiest way to make it sound better than the opositions was to create better drivers.
None of the fix it with eq, or more power. Transformers make a difference too. They aren't all equal.
Geoff
None of the fix it with eq, or more power. Transformers make a difference too. They aren't all equal.
Geoff
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