Smokehouse Bob, I have all kinds of respect for the math and simulations people run to dial in a baffle for a particular driver. But while you're waiting for that possibility I would just cut a 24" wide baffle at whatever height puts the driver at ear level, and allows 6" or so above it. That way you could be done in a few hours and have something to listen to while working on getting a precision baffle /driver fit.
What are those? They look to have good possibilities.
Don
What are those? They look to have good possibilities.
Don
Thanks! They are early 12" dia., 60's RCA console drivers, accordian surrounds with whizzers. I have been working on the SE 6BQ5 amp that came with these, still having troubles getting the inputs right. I need help to finish it. In the meantime, I have these drivers to put to good use. Several folks have said that since they came from a console, an open baffle is a good project for them. Your thoughts and help is greatly appreciated.
They look great for their age. OB of some type is the way to go. They may also go well in a full size BR, probably not so well in a ducted one.
Start with an 8x4 ft (standard size in your land? as large as you can) sheet of good ply, cut it in half. Cut the holes above the centre line. ie keep the drivers away from the floor. Add a few cleats and pannels to make it rigid, and provide depth so it will stand upright. You can tilt it back if you wish.
Start listening. At first, you may think it sounds too strong in the mid range. Don't compare with other speakers. Compare to live music.
Avoid tone controls. Move the speakers instead. Corner placement will bring up the bass. Experiment and enjoy.
Nodiak is right. You could be enjoying these whilst others are running the numbers.
Geoff.
Start with an 8x4 ft (standard size in your land? as large as you can) sheet of good ply, cut it in half. Cut the holes above the centre line. ie keep the drivers away from the floor. Add a few cleats and pannels to make it rigid, and provide depth so it will stand upright. You can tilt it back if you wish.
Start listening. At first, you may think it sounds too strong in the mid range. Don't compare with other speakers. Compare to live music.
Avoid tone controls. Move the speakers instead. Corner placement will bring up the bass. Experiment and enjoy.
Nodiak is right. You could be enjoying these whilst others are running the numbers.
Geoff.
Thanks Geoff! That's a 4' x 8' here as you stated, cut in half that will give me 2, 4' x 4' pieces (I knew that math would come in handy some day!). I'll try vertical side "wings" to keep it upright and a bit stiffer. I have a small pair of horn tweeters (cheap lil' things but they might do for now). How would these be wired in with the large drivers? Ihave no experience with crossovers or such connections. Capacitors in there somehow? Thanks again!
Hi Bob, you are welcome. Don't worry about the tweeters yet. Lets get the things making music!
You are venturing into several areas. Trying too much at once may negate the advantages.
Open baffle gives you a sound not had from anything else. Full range also. Both give great transient response. My take on full range is to get as much out of 1 driver as possible. If it does not provide what you want, then add tweeters, or combine with a sub.
Once you get the single driver set up, you listen, and listen, and listen, to your entire collection, then we think about improvements.
I will tell you this. If those old RCAs are any good (and they probably are) you'll bore your friends to death with your excitement.
BTW, I leave new projects running 24/7. Yep, even when I am sleeping.
Geoff.
You are venturing into several areas. Trying too much at once may negate the advantages.
Open baffle gives you a sound not had from anything else. Full range also. Both give great transient response. My take on full range is to get as much out of 1 driver as possible. If it does not provide what you want, then add tweeters, or combine with a sub.
Once you get the single driver set up, you listen, and listen, and listen, to your entire collection, then we think about improvements.
I will tell you this. If those old RCAs are any good (and they probably are) you'll bore your friends to death with your excitement.
BTW, I leave new projects running 24/7. Yep, even when I am sleeping.
Geoff.
Smokehouse Bob, with whizzers those 12"'s are designed to have at least some treble. You should be able to hear cymbals well enough to enjoy the song.
Adding the tweeters would require having the woofers up and running anyway so you can gauge how they work together. You may want to cut tweeter holes directly above the woofers so your cutting is done, but use a piece of wood to cover that hole until you've heard the woofers alone. My vote goes for not worrying about the tweeters for at least several days of listening to the woofers alone.
Personally I find for every hour I spend working on things I just traded off an hour of relaxed listening. I enjoy all the interest and fun of working on things but at some point I need to try to balance more towards listening again.
Just think you're woofers might be good to go by themselves.
Don
Adding the tweeters would require having the woofers up and running anyway so you can gauge how they work together. You may want to cut tweeter holes directly above the woofers so your cutting is done, but use a piece of wood to cover that hole until you've heard the woofers alone. My vote goes for not worrying about the tweeters for at least several days of listening to the woofers alone.
Personally I find for every hour I spend working on things I just traded off an hour of relaxed listening. I enjoy all the interest and fun of working on things but at some point I need to try to balance more towards listening again.
Just think you're woofers might be good to go by themselves.
Don
24/7 Geoff? Oh the Mrs. would like that, not! LOL I'll post back with pics and impressions once I get them mounted and going, but it may be awhile if I get enthralled. I have another pair, old 8" Alnico Fishers, full range but no whizzers. They were box-mounted inside their console, bare wood no stuffing. They may make another good candidate pair. Since the RCAs were open-air, cabinet mounted in their original console, we'll try them OB first.
Take care,
Bob
Take care,
Bob
Don, I think he's getting excited already. And Bob, trust thoses ears, they don't lie. Graphs can.
The 24/7 thing. When I first stir in the morning, and want to increase the dBs a bit, I know I am on to a good thing. If I go for the Jug to make some coffee, more work is needed. And if I cant sleep because I am enjoying the music so much, I don't need to.
Be patient man. Put those Fishers aside for now. Their time will come.
Oh and the wife factor. We split some time ago, for the better, so it's not an issue. I can now enjoy the music.
Geoff
The 24/7 thing. When I first stir in the morning, and want to increase the dBs a bit, I know I am on to a good thing. If I go for the Jug to make some coffee, more work is needed. And if I cant sleep because I am enjoying the music so much, I don't need to.
Be patient man. Put those Fishers aside for now. Their time will come.
Oh and the wife factor. We split some time ago, for the better, so it's not an issue. I can now enjoy the music.
Geoff
Bob, those look good. What is the 2nd, newer one? Octals? I only have a little experience with tubes and am currently looking for an integrated tube amp for some fullrange drivers I have - Fostex FE167e, FE108es, 8" Hempcone.
I'd be into some suggestions or discussing anything you may have to sell. I have some ideas of what I'm looking for, could be helpful to go over them.
nodiak@sbcglobal.net
Don
I'd be into some suggestions or discussing anything you may have to sell. I have some ideas of what I'm looking for, could be helpful to go over them.
nodiak@sbcglobal.net
Don
Don,
The second one is a Magnavox 6V6 PP, 1961-ish. Sound belongs to Magnavox, cosmetics are me just having fun! A nice amp, I have 3 or 4 like it. I have some bugs to work out on a couple of them. If successful, they may leave the stable. The first amp is an AA-50 Heathkit. Big ol' 7591s to heat the room! Here are the Fisher drivers.
Bob
The second one is a Magnavox 6V6 PP, 1961-ish. Sound belongs to Magnavox, cosmetics are me just having fun! A nice amp, I have 3 or 4 like it. I have some bugs to work out on a couple of them. If successful, they may leave the stable. The first amp is an AA-50 Heathkit. Big ol' 7591s to heat the room! Here are the Fisher drivers.
Bob
Attachments
Show off! Teazer!
Can you be sin binned for hyjacking your own thread? At least his last pic was an Old Consul driver.
6V6s in A-B PP. A nice 17 watts.
That's the sort of stuff I started on. Other peoples junk became my treasure. I can smell the dust burning on the bottles. Have a look at the Altec Lansing thread, after you have cut and assembled the baffles.
Geoff.
PS if freight wasn't what it was, I'd place an offer.
Can you be sin binned for hyjacking your own thread? At least his last pic was an Old Consul driver.
6V6s in A-B PP. A nice 17 watts.
That's the sort of stuff I started on. Other peoples junk became my treasure. I can smell the dust burning on the bottles. Have a look at the Altec Lansing thread, after you have cut and assembled the baffles.
Geoff.
PS if freight wasn't what it was, I'd place an offer.
Sorry about that Geoff, I couldn't resist sharing a view of what the OBs will be used with. Other people's junk is precisely right. That AA-50 was loaded with still good Mullards and Telefunkens. Cost me $2.95 and a hernia carrying it to the truck.Oh, and the PT-1 tuner that came with it was included in the $2.95! It was labelled "radio parts", HA! Bottom feeding is pure joy!
Smokehouse Bob said:
Greets!
Oh my! These bring back the memories! As others have suggested, these drivers are best suited for OB or aperiodically loaded cabs, so there's no such thing as too large a baffle (boxed or not), only a point of diminishing LF performance returns. Out of necessity, I was an early adopter of floorspace efficient tower designs, so stuck them in whatever the largest 'footprint' cab the 'client' could make room for and made up the difference in height based on the amount of material available and typically either made the back and/or bottom out of salvaged console/TV pegboard, spacing it up off the (usually rug or carpeted) floor as required.
Obviously, no real design science on my part at the time, if it wasn't in Cohen's book I was technically clueless beyond trying to mimic existing designs I had access to and what my own and the 'clients' ears told me for fine tuning. In my naiveté, I even scaled pictures using a Pantograph to fit a particular driver size. Though ultimately somewhat educational once I delved into horn design theory, as you can image, scaling huge cinema horns to various small drivers had some rather interesting results!
FWIW, since 'old' RCA and its Sears Silvertone branded electronics was the most commonly available 'on the cheap', 6K6 loaded amps ruled.
GM
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.