My 16 y.o. daughter told me a few weeks ago that she wanted to play vinyl. I fixed up her grandfather's AR-XA turntable, S/N 00302. There is a thread over at Audiokarma for the restoration. We had a Sony 6055 receiver for her to use.
For speakers, I was given a pair of the Infinity SM 62 bookshelf speakers, which fit her room size.
Front baffle 7"
Depth 6"
Height 12"
Volume 0.29 cubic feet
Port 1.5" x 3"
The crossover looks like maybe $1 in parts.
I can route and I can solder a new crossover.
Does anyone have any suggestions for components to upgrade the speakers. The 6" driver looks decent enough. The polycell tweeter looks limiting. The crossover cheap.
Thanks,
Joseph
For speakers, I was given a pair of the Infinity SM 62 bookshelf speakers, which fit her room size.
Front baffle 7"
Depth 6"
Height 12"
Volume 0.29 cubic feet
Port 1.5" x 3"
The crossover looks like maybe $1 in parts.
I can route and I can solder a new crossover.
Does anyone have any suggestions for components to upgrade the speakers. The 6" driver looks decent enough. The polycell tweeter looks limiting. The crossover cheap.
Thanks,
Joseph
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IMHO it is not worth "upgrading" a commercial speaker, even the more expensive ones. In fact you can't upgrade as a commercial speaker is an exercise in bringing down the costs without limiting too much the quality (at a given price point).
For a cheap speaker, given that the drivers are in good condition, I'd only replace any aged (*) electrolytic cap with similar ones (not poly).
If there is easy access to the inside there is the possibility to install a stiffener like this one: http://zaphaudio.com/SR71-insides.jpg
Anything above that is not worth the money and/or needs a substantial investment in measuring gear.
Ralf
(*) Some 10 years or more
For a cheap speaker, given that the drivers are in good condition, I'd only replace any aged (*) electrolytic cap with similar ones (not poly).
If there is easy access to the inside there is the possibility to install a stiffener like this one: http://zaphaudio.com/SR71-insides.jpg
Anything above that is not worth the money and/or needs a substantial investment in measuring gear.
Ralf
(*) Some 10 years or more
I agree with Ralf. Add some bracing, line interior walls with felt, replace electrolytic with same value but higher quality bipolar cap. Do not go to non electrolytic because bass response will go down. Any substantial change to actual driversbor crossover values will require a redesign and measurement equipment. Be happy with what you have 
Ok, I get it, no silk purse out of a sow's ear. The house rule for this project, was limited to stock on hand. So I cannot get new speakers. However, I can modify the existing ones. And with the AR-XA spinning vinyl, I want more out of the speakers.
Now I'm looking at changing out the drivers and crossovers. The 6" driver is routed to 7". The tweeter is routed to 3.5". New drivers in the old box. That's not new speakers, that's modifying the old ones.
Would the*Dayton DSA 175-8 and DC28F-8 work for the existing cabinets? I can do routing and solder .*
With the*Dayton DSA 175-8 being new, I cannot find any online projects using it.
Thanks,
Joseph
Now I'm looking at changing out the drivers and crossovers. The 6" driver is routed to 7". The tweeter is routed to 3.5". New drivers in the old box. That's not new speakers, that's modifying the old ones.
Would the*Dayton DSA 175-8 and DC28F-8 work for the existing cabinets? I can do routing and solder .*
With the*Dayton DSA 175-8 being new, I cannot find any online projects using it.
Thanks,
Joseph
You're weaving a cunning path to get around the ground rules but you're also playing it very loose with the design and building of the loudspeakers.... Because existing cabinets or no, you would be creating something wholly new.
IMO you would do better follow the advice above and refurb the x-overs....
Any other advice I would give would be along the lines of "oh no they caught fire! After I promised her the speakers too! Whatever will 'we' do to fix it!!!"...
IMO you would do better follow the advice above and refurb the x-overs....
Any other advice I would give would be along the lines of "oh no they caught fire! After I promised her the speakers too! Whatever will 'we' do to fix it!!!"...
Loopholes to house rules I see...
I am making a 2-way/3-way out of RS28F and RS180P over on this thread. It is starting as a 2-way and I plan to add a mid as a "hole filler" 3-way later. I have a nice waveguide but you can flush mount if you don't need a transient perfect time-aligned speaker.
http://www.diyaudio.com/forums/multi-way/297171-rs28f-rs180p-b80-hole-filler-3-way.html
Backside with two passive rads:
I will have to look at the DSA175...
listen to what everyone is saying. Im sure those speakers sound halfway decent the way they are. Unless you have software measuring and designing a new xover it wont be possible to make new drivers work in that box. I would rather take a set of old speakers and build new sturdier enclosures for them then to upgrade the drivers and keep the old crappy enclosure.
So I can just replace the 4.7 MFD cap, film quality OK? Easy enough for my skill level. There also looks like a third component in parallel with the cap. Best seen in the second pic, to the right of the cap. What is it? And should I leave or remove the fuse? Is it real protection or cheap sonic compromise?
Thanks, Joseph
Thanks, Joseph
Ones you mentioned it, it looks like a coil, as a part of second-order high-pass filter for tweeter. Difficult to see, please take another photo with better angle and light.
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Replacing cap with film MKT or MKP will change the sound for better (more detail), or worse (tweeter may become too obvious) - in this case add resistor 1 ohm or so. Replacing cap with quality bipolar electrolytic is a safe bet.
That is a self-resetting fuse for protection. If you play loud, better leave it there.
Sonce, I will take a look and pic later, when I get back home. The only safe assumption is that this was a 3 minute crossover design. If I assume 8 ohm impedance for both drivers, Ist order Butterworth with a crossover at 4200Hz, I get a cap of 4.73MFD and inductor 0.3mH. Do these number sound ballpark for a three minute design 30 years ago? Thanks, Joseph
The real reason for trying to get more out of the drivers:
AR-XA turntable restoration, TT 00302 | Audiokarma Home Audio Stereo Discussion Forums
AR-XA turntable restoration, TT 00302 | Audiokarma Home Audio Stereo Discussion Forums
OR, this one for less than HALF the $$$:
http://www.mouser.com/ProductDetail...EpiMZZMv1cc3ydrPrF5m%2btQWx%2bSdKcsBu4jvcDG8=
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