old radio cabinet antirestoration - old empty box new insides now with subwoofer
Hi all, sorry if this is in the wrong section but it's a bit of everything.
A few years ago I bought an empty radio cabinet for not much because I liked the bezel on it. I've since gotten around to stripping off all the old shellac/whatever, sanding it back and re-polishing it, and it has come up good enough to proceed to phase two, which is stick an amplifier and speakers and some kind of bluetooth or other source in it as some kind of oversized sound dock.
I'm no audiophile and I don't want to spend much on this so bear that in mind.
as it is now
an old one of the (now removed) rotten shelf that needs to be replaced
the challenge now is speakers, I basically want it to sound like an old radio, which is usually reasonable bass and not that much high frequency, I don't want to put tweeters in it.
the grille measures roughly 185mm (7 1/4") wide by 380mm high (just under 15 inches) so I can either use
- side by side 4" speakers, 2 X 4Ω or 4 X 8Ω
- top and bottom 8" speakers, 2 X 4Ω ideally
- some other system with two different sized speakers
- something else?
Some of these setups will probably require mono downmixing (which brings issues itself) and then there is the question of enclosures. mounting the speakers on a baffle will basically result in a dipole setup which is probably about right for an old radio, was looking at doing transmission lines but lost interest due to all the other constraints and I want to keep it pretty simple.
any ideas on speaker selection? there isn't that much selection here and I'm not keen on doing an international order, so just after general thoughts on size.
is some sort of loudspeaker enclosure worthwhile?
will cheap 8" speakers sound "better" than more costly 4" speakers (is size king?) the speaker previously in this box would have been ~10 inches or so based on the old baffle.
I'll be mounting whatever speakers I use to a 16mm MDF baffle to start, if it is all wrong I can add an enclosure later.
still need to make volume/tuning knobs and other things too, and work out something interesting to stick behind the bezel glass window...
Cheers!
Hi all, sorry if this is in the wrong section but it's a bit of everything.
A few years ago I bought an empty radio cabinet for not much because I liked the bezel on it. I've since gotten around to stripping off all the old shellac/whatever, sanding it back and re-polishing it, and it has come up good enough to proceed to phase two, which is stick an amplifier and speakers and some kind of bluetooth or other source in it as some kind of oversized sound dock.
I'm no audiophile and I don't want to spend much on this so bear that in mind.
as it is now
an old one of the (now removed) rotten shelf that needs to be replaced
the challenge now is speakers, I basically want it to sound like an old radio, which is usually reasonable bass and not that much high frequency, I don't want to put tweeters in it.
the grille measures roughly 185mm (7 1/4") wide by 380mm high (just under 15 inches) so I can either use
- side by side 4" speakers, 2 X 4Ω or 4 X 8Ω
- top and bottom 8" speakers, 2 X 4Ω ideally
- some other system with two different sized speakers
- something else?
Some of these setups will probably require mono downmixing (which brings issues itself) and then there is the question of enclosures. mounting the speakers on a baffle will basically result in a dipole setup which is probably about right for an old radio, was looking at doing transmission lines but lost interest due to all the other constraints and I want to keep it pretty simple.
any ideas on speaker selection? there isn't that much selection here and I'm not keen on doing an international order, so just after general thoughts on size.
is some sort of loudspeaker enclosure worthwhile?
will cheap 8" speakers sound "better" than more costly 4" speakers (is size king?) the speaker previously in this box would have been ~10 inches or so based on the old baffle.
I'll be mounting whatever speakers I use to a 16mm MDF baffle to start, if it is all wrong I can add an enclosure later.
still need to make volume/tuning knobs and other things too, and work out something interesting to stick behind the bezel glass window...
Cheers!
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Cool project.
I think there is little use in going stereo, since the drivers would be so close together that their output would mix anyways, but with unpredictable results.
A nice, large, efficient full range running open baffle would best bring the original sound back. You only need a small class D amplifier with a wall wart to get pretty loud. I don't know what is on sale in Oz, speakerwise.
Depending on your measuring equipment, you might consider adding a MiniDSP to flatten the frequency response, which is bound to be ragged without correction.
I think there is little use in going stereo, since the drivers would be so close together that their output would mix anyways, but with unpredictable results.
A nice, large, efficient full range running open baffle would best bring the original sound back. You only need a small class D amplifier with a wall wart to get pretty loud. I don't know what is on sale in Oz, speakerwise.
Depending on your measuring equipment, you might consider adding a MiniDSP to flatten the frequency response, which is bound to be ragged without correction.
yeah stereo is not required I'm just not sure if I want L fighting R each other with electrons or with air.
The amp I've got is 2 X 15watt per and based on the TA-2024 I believe, so I either need to use two speakers or let half of the power go to waste.
i'm going to wire this so I can run external speakers too if required as the amp sounds surprisingly OK and will be more useful that way.
My listening standards are very low, so as long as it sounds OK and has some semblance of low frequency i'll be happy.
The amp I've got is 2 X 15watt per and based on the TA-2024 I believe, so I either need to use two speakers or let half of the power go to waste.
i'm going to wire this so I can run external speakers too if required as the amp sounds surprisingly OK and will be more useful that way.
My listening standards are very low, so as long as it sounds OK and has some semblance of low frequency i'll be happy.
Does it need to be stereo? Old radios like that are designed for a single speaker, so the easiest route would be just that. Something like a single Selenium 8mb4p would give you that old radio sound and a lot of volume for not too many watts of amplifier. A full range driver wouldn't have that old radio sound, but would be a bit more hifi. The bigger the speaker, the more lows that will come through and the less highs as a general rule. The cheeper large speakers have even a bit less highs, but you often have to give them lots of power for little volume.
What's your price range?
What's your price range?
Out of curiousity (my daughter lives in Brisbane, who knows where I will wind up) I checked what down under has, loudspeakerwise, and it is not impressive. The only driver I found is this one.
PS220-8 8" Point Source Full-Range Neo Driver - Dayton Audio
In the US, there is much more choice.
This one would work, but is $$$$:
The Madisound Speaker Store
And this one probably is a bargain, even with transportation. Pioneer made some very nice drivers.
GRS 8FR-8 Full-Range 8" Speaker Pioneer Type B20FU20-51FW
Don't think cheap drivers can't be good. The specs on this one are pretty OK.
PS220-8 8" Point Source Full-Range Neo Driver - Dayton Audio
In the US, there is much more choice.
This one would work, but is $$$$:
The Madisound Speaker Store
And this one probably is a bargain, even with transportation. Pioneer made some very nice drivers.
GRS 8FR-8 Full-Range 8" Speaker Pioneer Type B20FU20-51FW
Don't think cheap drivers can't be good. The specs on this one are pretty OK.
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doesn't need to be stereo, just makes it easier in a lot of ways.
budget for speakers is about $60 (laugh if you want, I don;t mind
)can I link to sites here for reference? so far i've found a place that sells Visaton speakers (though my budget only buys their 4" range) and there are a few electronics stores that sell varios "generic" speakers, don't want to spend much as I can't imagine a 1 or 2 inch wide baffle directly in front of a loudspeaker will let it sound the best it can.
You might check out guitar speakers. They are pretty wide range, have decent lows, and are usually pretty loud for the wattage. I was just looking at the modest priced Jensen c8r 4 ohm version that looks almost exactly like what you are asking for, only a little over budget for two.
Go ahead and put links if you think it would help.
Go ahead and put links if you think it would help.
FWIW.... ...
Years ago my father used tell me abut the old" Philco" radio that his parents had when he was a kid.
When his mom passed in the '70s.... he got the radio and it was like very much like your pics and it was still quite pristine and worked perfectly.
Long story short........by this time I was no longer living at "home" .
One day. I was heart broken when he had the museum quality " Philco" in his cellar workshop and had completely butchered it----cutting it in half etc to fit on shelves .
I felt like he cut the "Mona Lisa" in half !
In any event, I agree that you should keep it mono.
Years ago my father used tell me abut the old" Philco" radio that his parents had when he was a kid.
When his mom passed in the '70s.... he got the radio and it was like very much like your pics and it was still quite pristine and worked perfectly.
Long story short........by this time I was no longer living at "home" .
One day. I was heart broken when he had the museum quality " Philco" in his cellar workshop and had completely butchered it----cutting it in half etc to fit on shelves .
I felt like he cut the "Mona Lisa" in half !
In any event, I agree that you should keep it mono.
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this is the 4"4 ohm speaker i'm considering Soundlabs Group FR 10 - 4 Ohm, LSK as linked earlier has 4 ohm dayton RS100s for about $30 each but I would have to cut down the frames to make them fit nicely which is a shame.
if I used two pairs of 4" 8 ohm speakers they would be about 10 bucks a piece, such as Radio Parts - Electronics Components - GENERAL PURPOSE probably better off going with fewer and better speakers.
these are the only easily sourced cheap 8" speakers i've found so far
Radio Parts - Electronics Components - GENERAL PURPOSE
this one would be OK (single only) would need something for the high frequencies too.
Soundlabs Group W 200 - 4 Ohm
what's a good way to go from stereo to (dual) mono between the source and amplifier? the most promising solution i've seen so far involved putting a 10k resistor inline with the left and right level outputs, then joining them together for a single output, but no real explanation as to why this resistance was chosen.
Running a single speaker would be ideal, but I could also run a woofer off one channel and another speaker off the other channel,
JoeDJ the main reason I bought the box was it was empty, not terribly collectible (as far as I know) and cheap, it was about $30 when I bought it, which is only a little bit more than I paid for the bottle of shellac based polish .
if I used two pairs of 4" 8 ohm speakers they would be about 10 bucks a piece, such as Radio Parts - Electronics Components - GENERAL PURPOSE probably better off going with fewer and better speakers.
these are the only easily sourced cheap 8" speakers i've found so far
Radio Parts - Electronics Components - GENERAL PURPOSE
this one would be OK (single only) would need something for the high frequencies too.
Soundlabs Group W 200 - 4 Ohm
what's a good way to go from stereo to (dual) mono between the source and amplifier? the most promising solution i've seen so far involved putting a 10k resistor inline with the left and right level outputs, then joining them together for a single output, but no real explanation as to why this resistance was chosen.
Running a single speaker would be ideal, but I could also run a woofer off one channel and another speaker off the other channel,
JoeDJ the main reason I bought the box was it was empty, not terribly collectible (as far as I know) and cheap, it was about $30 when I bought it, which is only a little bit more than I paid for the bottle of shellac based polish .
10k was probably convienient. It doesn't overload the audio source, and doesn't make a lot of extra noise. (Resistors generate noise in certain configurations like this one). If the only sources you use can power headphones, then I would use a lower resistance (100 to 1k ohm) for lower noise. See Voltage divider - Wikipedia, the free encyclopedia for how it works. Basically, as long as the resistances are the same it averages the two inputs.
That spg6618 speaker looks pretty nice for the money. It does simplify things since it's full range.
That spg6618 speaker looks pretty nice for the money. It does simplify things since it's full range.
That was understood.
My little story was not meant to criticize in any way what you are doing:
all good
thanks, sources will be either an MP3 player or similar for starters, then maybe a bluetooth reciever later on so might as well start with lower R. can always change out the resistors as needed.
I've been reading a bit about Dispersion and how it is influenced by Driver size, as this is more or less a point source that will be stuck at a random spot in a room and be expected to fill it with nice noise this may be worth considering.
I did a quick check by sitting a speaker (bass reflex, 8 inch woofer, some kind of tweeter, some kind of crossover) in the cabinet and taped a piece of wood over the tweeter then listened to if off axis a bit. the results weren't very conclusive as I assume the crossover point was high enough that each speaker was doing what it should be.
on the plus side the 8" driver fits in the grille pretty well with very little shrouding on the edges (still plenty due to the wide strips in front of the speaker)
If I understand correctly dispersion is less of a problem with an OB/dipole (please let me know if I shouldn't be using there terms interchangeably) after reading up on why 8 inch woofers aren't a problem in this regard on the "likwitz phoenix" open baffle speakers.
still sticking to 4 or 8 inch speakers I have two choices:
Use two 8" FR speakers in a mono setup
pro: more bass, more in the spirit of an old radio
con: might not sound as nice off axis, can probably add some tweeters later to help out with this but that's getting away from the intent.
Use 4 4" FR speakers in a stereo with the speakers too close together setup
pro: better high frequency reproduction, might sound better off axis, could even make a "convex" baffle to cover a wider area.
con: less bass
I'm sure i'm over-thinking this, the only real goal is to look nice and not sound terrible and I guess it isn't a big deal to try one method then the other one if I hate it. Still I like good design that doesn't cost anything extra, even if I'm using bargain basement speakers.
in regards to the baffle am I better off just mounting the speakers to a flat panel (front or rear will be determined by clearance and what is easier as cheap speakers are more often rear mount) of building an open back "5 sided box"?
If the 5 sided box is the way to go should it be just wider that the speakers or as wide as the whole cabinet?
here's the cabinet with the bezel fitted, pity the knob holes are so rough/don't line up very well. still need to source or make some knobs too.
and one with an 8 inch woofer behind it for an illustration of scale.
I did a quick check by sitting a speaker (bass reflex, 8 inch woofer, some kind of tweeter, some kind of crossover) in the cabinet and taped a piece of wood over the tweeter then listened to if off axis a bit. the results weren't very conclusive as I assume the crossover point was high enough that each speaker was doing what it should be.
on the plus side the 8" driver fits in the grille pretty well with very little shrouding on the edges (still plenty due to the wide strips in front of the speaker)
If I understand correctly dispersion is less of a problem with an OB/dipole (please let me know if I shouldn't be using there terms interchangeably
) after reading up on why 8 inch woofers aren't a problem in this regard on the "likwitz phoenix" open baffle speakers.still sticking to 4 or 8 inch speakers I have two choices:
Use two 8" FR speakers in a mono setup
pro: more bass, more in the spirit of an old radio
con: might not sound as nice off axis, can probably add some tweeters later to help out with this but that's getting away from the intent.
Use 4 4" FR speakers in a stereo with the speakers too close together setup
pro: better high frequency reproduction, might sound better off axis, could even make a "convex" baffle to cover a wider area.
con: less bass
I'm sure i'm over-thinking this, the only real goal is to look nice and not sound terrible and I guess it isn't a big deal to try one method then the other one if I hate it. Still I like good design that doesn't cost anything extra, even if I'm using bargain basement speakers.
in regards to the baffle am I better off just mounting the speakers to a flat panel (front or rear will be determined by clearance and what is easier as cheap speakers are more often rear mount) of building an open back "5 sided box"?
If the 5 sided box is the way to go should it be just wider that the speakers or as wide as the whole cabinet?
here's the cabinet with the bezel fitted, pity the knob holes are so rough/don't line up very well. still need to source or make some knobs too.
and one with an 8 inch woofer behind it for an illustration of scale.
Cool project! Nice that you are saving the cabinet. In our living room (salon) we have a pair of 1958 Fisher console speakers driven by a TA-2020 amp. They sound great. We use them for TV and music. Each has three 8" speakers wired in parallel, no crossover.
Also have a 1930s RCA radio that look similar to your model. A good bit of fun.
But for your cabinet my choice would be the Beta 12 LTA
You might need an inductor in front of it to tune it to the mellow sound you want. It's a surprisingly good driver. No idea of price or availability down there.
Also have a 1930s RCA radio that look similar to your model. A good bit of fun.
But for your cabinet my choice would be the Beta 12 LTA
You might need an inductor in front of it to tune it to the mellow sound you want. It's a surprisingly good driver. No idea of price or availability down there.
cheers! that driver is a bit pricey at $80 (times 2) plus whatever for shipping, but thanks for the recommendation. Plenty of 8 inchers to choose from if I get the upgrade urge later on and they should fit the same cutout.
the BG20-8 is $53 (Australian dollars, but we're pretty much at parity at the moment) here Soundlabs Group BG 20 - 8 Ohm, haven't looked into PE shipping prices but I think I'll stick with whatever I can find locally for cheap.
How about some organ or console speakers?
Speaker SET AND Crossover From A Yamaha Organ in Taree, NSW | eBay
Speaker SET AND Crossover From A Yamaha Organ in Taree, NSW | eBay
nice! I need to work out how to get a radio in mine eventually, maybe even an internet radio, saw a build guide for one that used a raspberry pi and an arduino, seemed rather excessive.
read up on this driver http://www.altronics.com.au/p/c2000a-redback-200mm-8-inch-8-ohm-10w-dual-cone-pa-speaker/ and a few people think it's pretty good, then there is this one which looks "bigger is better" http://www.altronics.com.au/p/c2002-redback-200mm-8-inch-8-ohm-30w-dual-cone-wide-range-speaker/ but the T amp I'm using is only rated to 10 watts at 8 ohms, so the cheap one it is, will be ordering from radioparts as a friend has an account there.
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