Hi guys,
I've got some old Fisher D-12 speakers I've had since I was young. I recently took them out of storage and want to rebuild them. They look like:
They don't sound overly great--the highs aren't bad but the mids are pretty much non-existent and the bass is muddy. They are very hallow and completely empty inside. The particle board is fairly thick though. I have zero experience building speakers but it seems like it would be fun to drop a couple hundred on rebuilding these with new crossovers and drivers. I would also fill them with something or at least reinforce the cabinet a bit, and add banana plugs at the back.
I'm looking at getting a pre-built 3-way crossover from parts-express (or somewhere similar), but my question is how would I hook up the tweeters since there's 2 at the top instead of just 1? I'm not sure what the crossover on them is like now but I can say I think all 3 of the smaller drivers are roughly the same. If I could though, I'd like to have the middle be a nice mid-range driver and the top 2 be actual tweeters. In that case, can I hook up the tweeters to the crossover in series? Assuming I have an 8ohm crossover, would I then get two 4ohm tweeters wired in series, making it 8ohm at the crossover?
Any other advice for this rebuild would be appreciated. I know it may not make sense to rebuild in this specific cabinet but I'd like to use it as a test/first project.
I've got some old Fisher D-12 speakers I've had since I was young. I recently took them out of storage and want to rebuild them. They look like:
An externally hosted image should be here but it was not working when we last tested it.
They don't sound overly great--the highs aren't bad but the mids are pretty much non-existent and the bass is muddy. They are very hallow and completely empty inside. The particle board is fairly thick though. I have zero experience building speakers but it seems like it would be fun to drop a couple hundred on rebuilding these with new crossovers and drivers. I would also fill them with something or at least reinforce the cabinet a bit, and add banana plugs at the back.
I'm looking at getting a pre-built 3-way crossover from parts-express (or somewhere similar), but my question is how would I hook up the tweeters since there's 2 at the top instead of just 1? I'm not sure what the crossover on them is like now but I can say I think all 3 of the smaller drivers are roughly the same. If I could though, I'd like to have the middle be a nice mid-range driver and the top 2 be actual tweeters. In that case, can I hook up the tweeters to the crossover in series? Assuming I have an 8ohm crossover, would I then get two 4ohm tweeters wired in series, making it 8ohm at the crossover?
Any other advice for this rebuild would be appreciated. I know it may not make sense to rebuild in this specific cabinet but I'd like to use it as a test/first project.
Yes, substitute those cone tweeters with just one tweeter.
Once you take them out, measure the impedance ( quite difficult with a tester/voltmeter: it measures DC resistance ...) and report; and, while pulling everything out 😀, make a schematic of the crossover.
That red button on the front, what is it ? Some kind of "circuit breaker" ?
Remove it from the circuit.
A new remake of the box would provide to mount the three drivers aligned on the vertical axis, so a new baffle. The duct for bass reflex operation could be positioned on the back, and some "acoustic absorber" carefully attached to the internals ( not the front baffle !! ).
As for new crossovers and drivers...isn't this job hard enough !?
Once you take them out, measure the impedance ( quite difficult with a tester/voltmeter: it measures DC resistance ...) and report; and, while pulling everything out 😀, make a schematic of the crossover.
That red button on the front, what is it ? Some kind of "circuit breaker" ?
Remove it from the circuit.
A new remake of the box would provide to mount the three drivers aligned on the vertical axis, so a new baffle. The duct for bass reflex operation could be positioned on the back, and some "acoustic absorber" carefully attached to the internals ( not the front baffle !! ).
As for new crossovers and drivers...isn't this job hard enough !?
Hi Haidenny,
I love the look of these older speakers and an experienced diyer could definitely work some mojo with them but........I've seen a few guys new this hobby try to do what you're doing and the thing is that it's actually easier to get better results just making a speaker following a proven design (of which there are many) rather than trying to bodge a pre-built crossover into an existing enclosure with random new drivers.
The characteristics of the enclosure, drivers and crossovers need to be designed to work together with respect to each other for best results.
One of our blunter members here recently died and I can actually hear him rolling around in his grave at your suggestion.
I love the look of these older speakers and an experienced diyer could definitely work some mojo with them but........I've seen a few guys new this hobby try to do what you're doing and the thing is that it's actually easier to get better results just making a speaker following a proven design (of which there are many) rather than trying to bodge a pre-built crossover into an existing enclosure with random new drivers.
The characteristics of the enclosure, drivers and crossovers need to be designed to work together with respect to each other for best results.
One of our blunter members here recently died and I can actually hear him rolling around in his grave at your suggestion.
Yes, substitute those cone tweeters with just one tweeter.
Once you take them out, measure the impedance ( quite difficult with a tester/voltmeter: it measures DC resistance ...) and report; and, while pulling everything out 😀, make a schematic of the crossover.
That red button on the front, what is it ? Some kind of "circuit breaker" ?
Remove it from the circuit.
A new remake of the box would provide to mount the three drivers aligned on the vertical axis, so a new baffle. The duct for bass reflex operation could be positioned on the back, and some "acoustic absorber" carefully attached to the internals ( not the front baffle !! ).
As for new crossovers and drivers...isn't this job hard enough !?
Yeah it's a circuit breaker... and you're right, might just be easier to forget the crossover/drivers 😀
Thanks, after doing more research I've kind of come to that resolution as well. I might just keep them as nightstands lol
Chances are: take everything out !
Make a naked OB, play with EQ .
Arrange the two tweeters in real dipole !🙂😀
Game over! New one: change the tweeter > put it in the place of the midrange
unit >>change the midrange ! Why ( and more over: the crossover is more difficult )? Because now it acts like a filler, but you'd want it more pronounced, which leads to a real 300-3000 (telephone band, circa...) Hz range.
Make a naked OB, play with EQ .
Arrange the two tweeters in real dipole !🙂😀
Game over! New one: change the tweeter > put it in the place of the midrange
unit >>change the midrange ! Why ( and more over: the crossover is more difficult )? Because now it acts like a filler, but you'd want it more pronounced, which leads to a real 300-3000 (telephone band, circa...) Hz range.
Kudos for taking the news so well, some newbies don't like being told their dreams are more complicated than they realize.
That said once you get a bit more experienced you could certainly play around with them if you want 🙂 They'd be a fun project and as picowallspeaker is saying, lots of options 🙂
That said once you get a bit more experienced you could certainly play around with them if you want 🙂 They'd be a fun project and as picowallspeaker is saying, lots of options 🙂
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