The Franken-Can: R2D2 goes back to the future

[stoutblock]

Good god!

What are those 3 tubes? (first dibs)

What ever you do, I would make a complete box to install inside this cavity from the rear. This thing may buzz at low Hz?

 

[ccotenj]

Good god!

What are those 3 tubes? (first dibs)

What ever you do, I would make a complete box to install inside this cavity from the rear. This thing may buzz at low Hz?

not sure on the tubes... i'll look tomorrow and see what i can identify on them... if they turn out to be something you want, dibs are yours... tubes are another thing i know nothing about... i only remember them from when i was a kid, and when the tv wouldn't work we had to bring tubes to the store and put them on the tester...

yea... that's a good idea... it probably will have some resonance... i was also planning on putting the speaker on some type of vibration damping material... i'm also going to brace the bottom of the cabinet from side to side and across to add some structural integrity to it, and may do that in another place as well, depending on how things work out... removing 300 pounds of "stuff" out of the inside of it made it a bit more flexible (although not as much as i thought it would)...

thanks for the input!

 

[ccotenj]

the can shows a little leg...

progress has been made for 3 days in a row... always a positive thing...

got part of it stripped today... still a ways to go, but it's going reasonably well... a couple of pics...

 

[juniorJBL]

ccotenj

Maybe take a look at the Indignia thread. They are 2 way bookshelf speakers that you can build. very nice sounding as well.

You could also put a small sub below them.

Also as was said above, rattle may be an issue. I would think about, after cleaning up the case, maybe a coat of undercoating on all metal inside. There will be other things you could use as well.

I do think you should have speakers with their own enclosures.

Can you do metal working? A perforated area on each side of the front door could be nice for stereo separation or as was said above an offset between speakers for better separation.

Maybe think about using a piece of plywood for the rear of the cab. It wood give it some more strength.

:thmbsp:

OOPS: Just lookin at your new pics the light channel would be in the way of perfs where I was thinking of.

 

[ccotenj]

i'll check that one out, thanks...

as far as the rattling/resonances go... thinking about that, the best way to go may be to borrow from the car audio world, and use a cld like damplifier...

yea, making a back door is a good idea too... another item to add to the list...

 

[ccotenj]

re: speakers...

after perusing the indignia thread, i did some searching around for kits...

how about the recession buster kit from madisound? total cost is not much more than indignia's, and has the big advantage (for me) of coming with pre-cut cabinets...

 

[ccotenj]

something i hope someone will comment on...

when i first started this, i "guessed" that a mono configuration would be the best way to go, because i have no experience with placing a pair of speakers right next to each other, and simply assumed that there would be issues with that...

that's what led me to thinking about a diy solution in the first place... since i assumed i would only use one speaker, i figured it was worth a shot to see if i could build it... that's what led me to the ewave thread... and thinking that the basic ewave would probably work out pretty good...

however, judging from the responses in this thread, no one seems too concerned about having a pair of speakers right next to each other...

so was i that far off base in my original assumption? give it to me straight, i'm a big boy and can take it when i'm told i'm off in left field...

 

[6v6coalbed]

I like the jukebox idea. I wanted to build something similar a while back, but got into consoles instead.

I don't know what kind of budget you're looking for- if you want a pair of reasonable small bookshelf speakers and a subwoofer, and you want it simple, and at a good price, check out the DIY speaker and subwoofer kits from Parts Express. They even sell 2.1 plate amps to make the whole thing "just work". I'll bet the Madisound kits sound great, but you could do an entire powered Parts Express rig for half the cost, complete with amplifier. I think they even sell iPod docks with power and line out.

That close together, you won't get much stereo separation (and certainly less if using a compressed music source). You will get some high frequency comb filtering from having the speakers so close together. There's also the "live-sounding" psycho acoustic effects of having a speaker array.

Speaking of speaker arrays, you could do an array of reasonable, yet inexpensive extended-range 4-5" midrange speakers, plus a wide-dispersion tweeter or two (if stereo) and a large bass speaker. Following the curved front will raise the frequency where comb filtering becomes an issue, and you could cover most of the sonic spectrum (200Hz-5kHz?) without a crossover point in the delicate 1-3kHz region, and have the array dynamics to boot. If you still want stereo, you could probably fit two 2x4 arrays, or do a mono 'sweet 16'- a 4x4 array of 4" speakers with a tweeter to cover the high end that'll get munged from comb filtering.

I've only briefly studied the econowave threads, but Parts Express has a 12" waveguide on sale, with a published low-frequency cutoff of 1200hz that would probably mate nicely with a midbass/midrange-oriented 10" or 12" driver (PA type, perhaps), which would also probably work well in an open-baffle type cabinet (making your construction job that much easier). Then you can bi-amp with any 'ole 2-channel amp.

Just some thoughts. Again, neat project!

 

[ccotenj]

thanks for adding to the "speaker list"... and thanks for the encouragement...

some responses from me...

- when i was doing the "feasibility study" for this (i.e. daydreaming when i should have been working :nono: ), i put a $500 price tag on the speaker(s)... that's reasonably flexible, but i have no desire to enter the land of diminishing returns...

- i'm beginning to come to the conclusion that mono is the way to go... there doesn't seem to be any real benefit from attempting to go stereo...

- i'm fascinated by the idea of arrays (plus they look cool), but don't know where to start with that... re: sweet 16. how would something like that work? any links for something i can read?

 

[westend]

If you're getting into the mono mode, there are a variety of 12" and 15" coaxial and triaxial speakes that could be simply mounted on a straight baffle and left to run in open baffle arrangement.

The Madisound kits look pretty good to me and offer an advantage, if you ever wish to vacate the juke, you still have a pair of usable speakers.

 

[6v6coalbed]

Oh yeah. Forgot about the large coax/triax units. Easy way to go, if you can find a good one. Big units from the 60s-70s are very popular. There was a modern Eminence 12" unit that people liked well enough (Beta12-cx, I think), and became the basis for the Hammer Dynamics 12, which is supposed to be a fantastic speaker.

Google "sweet 16 speaker". I've heard mixed reviews- big arrays of speakers can sound neat, but the originals were hampered by using cheap low-fi table radio speakers. 16 identical speakers were wired series-parallel to maintain the original impedance. Below a certain frequency (the wavelength between cone centers), an array (including line arrays) of speakers will largely act like a single driver. (4" speaker = 4" center-center spacing. Speed of sound in air is around 1130ft/sec- a tone of 1130Hz will have a wavelength of about 1 foot.) So a 4" wavelength would be 12/4 * 1130 = 3.4kHz. Please correct me if my arithmetic is wrong here.

Parts Express usually has some good "buyout" speakers at a few dollars each- including Vifa and Audax and various TV speakers. Some of the Jamo-brand woofers they've got are real studs- they use high-inductance voice coils to get expensive bass performance out of small magnets at dirt-cheap prices, and look like a great value. Midrange rolls off at 1kHz, but it's a woofer.

 

[ccotenj]

If you're getting into the mono mode, there are a variety of 12" and 15" coaxial and triaxial speakes that could be simply mounted on a straight baffle and left to run in open baffle arrangement.

The Madisound kits look pretty good to me and offer an advantage, if you ever wish to vacate the juke, you still have a pair of usable speakers.

yea, the more i think about it, the more i think that mono is the way to go... i'm still open to being convinced otherwise though...

re: coax/triax. are you referencing something like this from paudio?... if so, that would be a definite option... i like simple solutions (especially when i'm doing it for the first time), and that seems like it would be simple and sound good... looks like i can get a pretty reasonably priced 12 or 15 inch driver, and the cabinet build (other than cutting that big hole in the front) wouldn't be too difficult... i gotta start searching the "friends of friends" directory to see if i can find someone to help me build it...

i'm liking this idea... what are the potential drawbacks?

your thought process on the madisound kit was the same as mine...

 

[ccotenj]

Oh yeah. Forgot about the large coax/triax units. Easy way to go, if you can find a good one. Big units from the 60s-70s are very popular. There was a modern Eminence 12" unit that people liked well enough (Beta12-cx, I think), and became the basis for the Hammer Dynamics 12, which is supposed to be a fantastic speaker.

Google "sweet 16 speaker". I've heard mixed reviews- big arrays of speakers can sound neat, but the originals were hampered by using cheap low-fi table radio speakers. 16 identical speakers were wired series-parallel to maintain the original impedance. Below a certain frequency (the wavelength between cone centers), an array (including line arrays) of speakers will largely act like a single driver. (4" speaker = 4" center-center spacing. Speed of sound in air is around 1130ft/sec- a tone of 1130Hz will have a wavelength of about 1 foot.) So a 4" wavelength would be 12/4 * 1130 = 3.4kHz. Please correct me if my arithmetic is wrong here.

Parts Express usually has some good "buyout" speakers at a few dollars each- including Vifa and Audax and various TV speakers. Some of the Jamo-brand woofers they've got are real studs- they use high-inductance voice coils to get expensive bass performance out of small magnets at dirt-cheap prices, and look like a great value. Midrange rolls off at 1kHz, but it's a woofer.

i did some searching around for line arrays after you posted that last night... found a little bit about the sweet 16 and a lot about other arrangements... it certainly sounds like an interesting option... big sound from a bunch of little speakers...

seems i say that about every option... being a whole new world to me, every option that is presented is interesting...

i'm digesting your math... i think i need another cup of coffee before i attempt to wrap my mind around that...

 

[westend]

yea, the more i think about it, the more i think that mono is the way to go... i'm still open to being convinced otherwise though...

re: coax/triax. are you referencing something like this from paudio?... if so, that would be a definite option... i like simple solutions (especially when i'm doing it for the first time), and that seems like it would be simple and sound good... looks like i can get a pretty reasonably priced 12 or 15 inch driver, and the cabinet build (other than cutting that big hole in the front) wouldn't be too difficult... i gotta start searching the "friends of friends" directory to see if i can find someone to help me build it...

i'm liking this idea... what are the potential drawbacks?

your thought process on the madisound kit was the same as mine...

My thoughts on coaxials and triaxials were more generated by vintage drivers of those types: Goodmans, Stevens Trusonic, EV, and others. Before I bought one of those PA speakers, for those prices, I would consider an Altec 604 from Great Plains Audio or a Silver Iris from Hawthorne. That is mostly pricing consideration as I have no direct knowledge of the PA driver. I think a vintage triaxial or coaxial can be had for a lot less on the vintage used market than buying new and that is the way I would proceed if incorporating it into the juke and going to a mono system.
BTW, is there anything wrong with the original driver that came with the jukebox? If a resurround is needed, that might be the most cost effective restoration and would let you listen to the original presentation of the machine. Going forward, it might be a consideration for resale, as well. I'm guessing there are jukebox collectors that are looking for all of the parts of that machine. The amp, control electronics, record changer, and other pieces might have lot of value to the right guy. Keep on truckin', there will be a speaker solution that comes.

 

[ccotenj]

^^^

fwiw, i'm really liking the full-range idea a LOT... seems to combine a lot of function into an easier to work with package...

re: silver iris... is this what you are referring to?

i'll have to do some searching on the "vintage" angle... my quick look showed many different "flavors" of the 604 you mentioned...

re: the old speaker... it would need some "work"... my thought process on "new speaker vs. old" is that i was hoping to come up with something that sounds better than the old one... i'm not too concerned about keeping it original at this point, since i'm not going to put anything else original back in it...

i'm certainly hoping that someone will want the stuff i took out of it... i need to take some time and inventory it and see what's there... i gotta believe that the record changing mech has some value... it'll be local sales though, that mech weighs a veritable ton... practically killed me getting it out of there...

thinking out loud...

i wasn't planning on doing so, but i can always re-install the inner skin back on the door... the original driver that was mounted to this is 15"... i'm wondering if, at least for "phase 1", if i could get away with just mounting 15" full-range (or coax) in free air like that? i wonder if the jukebox itself at that point would have the net effect of an open baffle? :scratch2:

this is a pic of the back of the door with the inner skin attached...

"front side" of inner skin...

 

[ccotenj]

after an exchange of emails with darrel and diana at hawthorne audio (VERY friendly and helpful folks), we have white smoke coming from the tower... :yippy:

what the heck, a dancing banana or two to commemorate the occasion as well...

for fcv1, "we" have ordered a silver iris ob 15 and bolt it right up to the baffle where the old speaker was...

this will be the "simplest" solution, is cost effective (comes in way under budget), and should work well, since the driver was designed for an open baffle config...

however, i hope this doesn't stop the speaker discussion, because i am learning a lot, and i'm also considering a couple other projects that i can apply any speaker ideas to...

 

[ccotenj]

lighting control

something else to wrap your brains around...

i have to replace all the lighting... i think it would be prudent to go with an led's... it definitely would NOT be prudent to put what was in there back in...

for reference, this is what a restored one looks like...

here's what i need to do...

1) backlight the red plastics on the sides. clear bright light. the plastics are thick.

2) backlight the red plastics on the top. again, clear bright light. these plastics aren't quite as thick.

3) backlight the dome. color would be nice here. both the ability to throw a solid color and the ability to animate it. mounting options are slim here, but my idea is to cannibalize the existing bracket that the old "revolving" animation was on and use that to mount the lights...

4) backlight the button/coin drop area. clear lighting, although colors might be interesting.

and a circuit to control all of the above...

edit: there's one more light. if you look at the restored one, you can see some light coming from the bottom of the grill... that'll probably end up just being a cfl...

 

[westend]

All right, a Silver Iris! That should work out good.

All I know about lights involving audio stuff is that LEDS are great if you want to make a smallish glow but they don't diffuse well. I've retrofit tuners and other with LED's and it is kind of a pain. I like the look of the incandescent's that came with the vintage stuff, also. What was the stock lighting that was behind those plastic panels?

 

[Fred Sanford]

something else to wrap your brains around...

i have to replace all the lighting... i think it would be prudent to go with an led's... it definitely would NOT be prudent to put what was in there back in...

for reference, this is what a restored one looks like...

here's what i need to do...

1) backlight the red plastics on the sides. clear bright light. the plastics are thick.

2) backlight the red plastics on the top. again, clear bright light. these plastics aren't quite as thick.

3) backlight the dome. color would be nice here. both the ability to throw a solid color and the ability to animate it. mounting options are slim here, but my idea is to cannibalize the existing bracket that the old "revolving" animation was on and use that to mount the lights...

4) backlight the button/coin drop area. clear lighting, although colors might be interesting.

and a circuit to control all of the above...

edit: there's one more light. if you look at the restored one, you can see some light coming from the bottom of the grill... that'll probably end up just being a cfl...

You need this:

http://www.hobbytron.com/Power-Blaster-Color-Organ-Kit.html

Cool project, thanks for sharing.

je

 

[ccotenj]

yup, it sure seems like the right tool for the job... it should fit right on there (screw pattern looks to be the same)... it should produce some pretty good sound... and it should be pretty easy, which is an important consideration for version 1...

re: lighting. that's a good point on the led's, and something i didn't think of. i was thinking that led's would be a good choice for coolness/energy efficiency, but the lack of diffuseness would be a real problem with backlighting.

1) top plastics are probably lit by 44/47 bayonet bulbs (can't tell, mount is missing, but i'll look it up in the service manual). these were used in a LOT of coin op machines for a long time. i'm sure they were originally 44's. 47's replaced 44's as they ran much cooler, but not until long after this machine was out in the wild. link to specs on 47 bulbs

2) the dome illumination was provided by a "standard" incandescent bulb. this sits in a little rotating cylinder within the dome. the rotating cylinder has (or more correctly, had) a covering with colors on it.

3) the side plastics look to be #81 bayonet bulbs. again, they were probably something different "back in the day", but went to a more "modern" bulb (the 81) somewhere along the line. link to 81 bulbs

4) coin drop is likely 44/47's as well. i haven't gotten the control mechanism completely apart yet, as i'm taking careful notes along the way of how it came apart, so it's taking a long time.

possible incandescent solutions might be:

1) replace the top plastics/coin drop with what is there. same deal on the coin drop. i've got #47 bulbs and sockets lying around as spares for my pinball machine. i should be able to cannibalize the transformer out of the "parts pile". assuming i can identify it and it works.

2) i can get the entire dome "animation" as a repro part. i need to get a few new pieces for that anyway, so to get the entire thing would be a minimal increase in cost.

3) the big plastics. there's a couple of options here. i could just string together a "new" string of 81's (or something close). that's just patience work, and i could draw power from the same transformer that is used for the #47's. i also might be able to cannibalize a string or two of christmas lights so that i don't have to make the new string, but socket fitment in existing hole would be a problem there.

all of the above assume new wiring. i don't dare put any of the old stuff back in there.

i wish i could figure out a way to replace the big plastics with something else. that repro set costs $375. :tears: and used ones are not available, period.