I’ve gutted out the electronics out of a Motorola console and want to use it in my office / man cave room. It was a solid state receiver with a broken phono. I will be using a renovated Dynaco ST 70 tube amp, Pioneer RT707 RTR and possibly a tt in the future (preamp to be determined). I just like the look of it and wanted to create some speakers inside of it that would play well with my gear. Each speaker enclosure is 15”w x 21”h x 15”d (2.7cf) and the center enclosure is 26”w x 16”h x 15” deep (3.6cf). I am no audio/electrical engineer but I can follow instructions. The room is small, 12’x13’ and it will be placed center of a 13’ wall. I would like to keep the budget around $500 but can adjust if needed. The drivers that I took out were working and consisted of a 12” woofer, 6” mid and horn tweeter and are marked Golden Voice and I know nothing about them (pictures attached). I listen to everything from Jazz, classical, 70s rock to country. I would like the speakers to be high efficiency so that they can be driven easily.
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If all the drivers are functional it might be sensible to listen to them, but before connecting them to a low powered amp.
Use a DVM set to the ohms range directly across each speaker to see that they are not open circuit or a short circuit.
The magnets are pretty small in size which could mean they have efficient alnico magnets, NB some people pay a fair amount of money for old drivers with alnico magnets.
At the same time they may be very sensitive drivers hence the horn loaded tweeter, so please don't just put them in the re cycling bin.
If they are serviceable and they sound passable when back in the cabinet acting as a large baffle all you may need to do is to change the potentiometer on the tweeter (if there is one, maybe its off the page of your attached diagram) and maybe the 3.3 uF capacitor. Which could save you some money.
You have a nice cabinet to which you can add your dynaco. As they appear to be an open back design get them against the man cave wall and don't expect to have massive bass, I guess they will need no more than a few watts to bring them to life. Be careful with the volume control initially.
Use a DVM set to the ohms range directly across each speaker to see that they are not open circuit or a short circuit.
The magnets are pretty small in size which could mean they have efficient alnico magnets, NB some people pay a fair amount of money for old drivers with alnico magnets.
At the same time they may be very sensitive drivers hence the horn loaded tweeter, so please don't just put them in the re cycling bin.
If they are serviceable and they sound passable when back in the cabinet acting as a large baffle all you may need to do is to change the potentiometer on the tweeter (if there is one, maybe its off the page of your attached diagram) and maybe the 3.3 uF capacitor. Which could save you some money.
You have a nice cabinet to which you can add your dynaco. As they appear to be an open back design get them against the man cave wall and don't expect to have massive bass, I guess they will need no more than a few watts to bring them to life. Be careful with the volume control initially.
if the budget was a little better i'd say go active three way with a mini dsp or some such, i've heard the driver set in it's original form and always thought they could be made better with time alignment, that horn has the treble driver way deeper than the mid...or horn load the mid....oops forgot it's your project....
Thank you for the suggestions. The horn tweeter noise filter switch which was removed with the electronics. I am not opposed to using the existing drivers. I can seal in the speaker enclosures as well. I did want to add a new crossover. I will freely admit that my knowledge on speaker wiring is very limited. I am not trying to achieve hi-if nirvana with this setup but I would like something that I can enjoy. I have Klipsch Heresy speakers connected to another Dyanco in my living room and would like to replicate the sound as close as possible given the limitations with the console and budget.
your most of the way there other than a horn loaded midrange, it would be tight but minimizing the spacing between all the drivers would allow you to vertically stack all the drivers and you could change the orientation of the tweeter horn. i'd even consider mounting the horn to the outside of the grill to change the time alignment, i wouldn't seal the enclosures those woofers are happiest in semi open or aperiodic (read resistive vent) boxes.
incidentally that tilt back that the Heresy has is a "cheat" form of time alignment, so yup you like time aligned speakers...maybe?
incidentally that tilt back that the Heresy has is a "cheat" form of time alignment, so yup you like time aligned speakers...maybe?
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Ah! A simple switch to disable the horn tweeter perhaps. I wondered where that wire was going to on the LHS of the schematic!
If continuing to use these drivers, I would strongly advise replacing the 3.3uF capacitor with a modern equivalent, as its value has no doubt drifted from spec by now. I would replace it with a polypropylene film capacitor of the type shown in the attachment.
P.S. A simple way to upgrade is to build a pair of speaker enclosures whose dimensions allow you to simply sit them in the speaker compartments of the console, where they can fire out through the concealing front grill of the console.
There's lots of speaker kits to choose from out there that would make that task easy.
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having heard the driver set i would stay with those....but i would go three way active...but that's me!
Actually, the schematic shows a 33uF capacitor in series with the mid driver, not 3.3uF.
I'm not sure how the horn tweeter is wired into the combination of woofer and mid.
Does anyone know what's going on there?
I'm not sure how the horn tweeter is wired into the combination of woofer and mid.
Does anyone know what's going on there?
i believe it's actually a two way with a "filler" mid and i'll likely be publicly chastised for saying that that 16 ohm mid is there more as an inductance for the tweeter.
Whoops my bad on the 3.3uF instead of the real value of 33uF.
That's an interesting value does anybody know the basic crossover frequencies or would care to hazard a guess.
That's an interesting value does anybody know the basic crossover frequencies or would care to hazard a guess.
P.S. 33uF polypropylene capacitors are available but relatively expensive (around £12), so perhaps go for a bipolar (NP) electrolytic capacitor like this: 33 fd ECap100 Electrolytic Capacitor (just £2).
I hope I'm not being unnecessarily detailed, but Mike did admit that his knowledge on speaker wiring is very limited. 🙂
I hope I'm not being unnecessarily detailed, but Mike did admit that his knowledge on speaker wiring is very limited. 🙂
Could there be an inductor situated in the "horn tweeter filter switch" which was removed from the electronics?
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The LH end of the capacitor is wired to the RH terminal on the horn. The wire on the LH terminal of the horn then disappears off to the "horn tweeter noise filter switch" after which it returns to the RH end of the capacitor.
I'd really like to see the circuitry of that horn tweeter noise filter switch.
I'd really like to see the circuitry of that horn tweeter noise filter switch.
Sorry, turk, I don't get that question.
EDIT: Oh! the horn tweeter is in parallel with the mid you mean. Not according to my description of the wiring.
EDIT: Oh! the horn tweeter is in parallel with the mid you mean. Not according to my description of the wiring.
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Those mids suck. The other drivers are not over the top either. The XO network is judt enuff to kep things from blowing up.
You have 2 choices, you can build boxes into the console or just do a new baffle and do an OB or baffle.
The 1st thing i would look at is a single FR driver suitable for an OB that can do bass without a helper.
The Betsy 8” or the Visaton B200 (with phase plugs to deal with the laser beam top). Simple, elegant and good sound.
Building a box gives many more options, i am still partial to single FR drivers
dave
You have 2 choices, you can build boxes into the console or just do a new baffle and do an OB or baffle.
The 1st thing i would look at is a single FR driver suitable for an OB that can do bass without a helper.
The Betsy 8” or the Visaton B200 (with phase plugs to deal with the laser beam top). Simple, elegant and good sound.
Building a box gives many more options, i am still partial to single FR drivers
dave