Hello all
I brought this pair of RCA 64-B monitors up a while back, but I became quite ill and never followed up. If you responded please forgive me if you didn’t hear back from me.
When a doctor starts talking about one’s future lifespan in terms of months it does funny things with your head.
By the grace of God they were wrong and I’m still here!
These came with the original drivers but they are in poor shape. I’m hoping some can recommend some replacements. I tried a pair of Altec 409A’s which had amazing bottom end in these cabinets but little on top. I may be wrong on the Altec #. they were ceiling mount units that I though were 8” diameter, but the data in the attachments seem to indicate 6.5” drivers.
since I’m fortunate enough to still be here to toy with them I’m hoping someone can recommend a driver.
I remember them being incredibly efficient and sounding great. I’m really curious what they’ll sound like with drivers that weren’t intended for mounting in
elevator cars!
Thanks in advance,
Rick
I brought this pair of RCA 64-B monitors up a while back, but I became quite ill and never followed up. If you responded please forgive me if you didn’t hear back from me.
When a doctor starts talking about one’s future lifespan in terms of months it does funny things with your head.
By the grace of God they were wrong and I’m still here!
These came with the original drivers but they are in poor shape. I’m hoping some can recommend some replacements. I tried a pair of Altec 409A’s which had amazing bottom end in these cabinets but little on top. I may be wrong on the Altec #. they were ceiling mount units that I though were 8” diameter, but the data in the attachments seem to indicate 6.5” drivers.
since I’m fortunate enough to still be here to toy with them I’m hoping someone can recommend a driver.
I remember them being incredibly efficient and sounding great. I’m really curious what they’ll sound like with drivers that weren’t intended for mounting in
elevator cars!
Thanks in advance,
Rick
Attachments
An Olson/Nagaoka style horn. I have drawn something similar.
If you build the horn in HornResp and start installing different drivers. The horn will only affect frequencies less than 250-300Hz. Above that you want o look at the native response. If you are plugging a fullrange driver keep in mind that typical listening is a bit off axis.
dave
If you build the horn in HornResp and start installing different drivers. The horn will only affect frequencies less than 250-300Hz. Above that you want o look at the native response. If you are plugging a fullrange driver keep in mind that typical listening is a bit off axis.
dave
At first-glance, that thing looks to be about exactly Mellow Monster sized but smaller the 194X/contemporary Aus versions if that helps jog anybody.
At any rate, glad you're still among us @Technical (and Dave for that matter) 🙂
At any rate, glad you're still among us @Technical (and Dave for that matter) 🙂
Popular Electronics 1962-October has the Mello Monster article.
https://worldradiohistory.com/Archive-Poptronics/60s/62/Pop-1962-10.pdf
It was my first speaker, inherited from a friend of my Dad's when that friend converted to the new-fangled thing, stereo. It was fitted with an Electrovoice LS-8. I was probably 16 at the time. Fond memories!
https://worldradiohistory.com/Archive-Poptronics/60s/62/Pop-1962-10.pdf
It was my first speaker, inherited from a friend of my Dad's when that friend converted to the new-fangled thing, stereo. It was fitted with an Electrovoice LS-8. I was probably 16 at the time. Fond memories!
Another cool driver I didn't know existed--thanks @NeonDriver
@Technical - if you want to dust-off your EE hat, PM me an email and I can send the paper that I think to be the genesis of that thing and you can hunt for good fits. Might be a sort of retired-guy-fun to try to follow 193X Olson-tracks (?) There's lots of sleuthing to be had--that paper, the driver patents, all good stuff for (retired) speaker junkie history buffs.
Just skimming it again, he never said what size the chamber was, but might be divined backwards from the plot of reactance. The throat, mouth and length are in the paper (16, 300, 92) and the flare is 34Hz. Looks kinda fun but I fear my facility to bash through verifying matching driver and throat impedances is about 50 years in the rearview. You, of course, can just measure what's missing. If you have those dimensions from the cabinets, you can do Hornresp quickies w/o going "full-Olson".
Perhaps worth consideration is to photograph details of both the cabs and the original drivers as they'll not be made again and few are left. Learned only this week that the guy I was going to ask about those original drivers has now passed. AK might be a good place to post that stuff for posterity as well. If nothing else, the hole/cutout size and mounting (bolt-circle) info need to be known.
I don't think there's anything made now that can approach whatever the MI-4411 field-units did...different world/times. You might as well use anything from the sims I've done on the (slightly larger) Australian version--everything is rough (but that doesn't mean it can't make you smile). I might well be wrong--but at least the paper shows what he was trying to do and I didn't go through the work to try.
@Technical - if you want to dust-off your EE hat, PM me an email and I can send the paper that I think to be the genesis of that thing and you can hunt for good fits. Might be a sort of retired-guy-fun to try to follow 193X Olson-tracks (?) There's lots of sleuthing to be had--that paper, the driver patents, all good stuff for (retired) speaker junkie history buffs.
Just skimming it again, he never said what size the chamber was, but might be divined backwards from the plot of reactance. The throat, mouth and length are in the paper (16, 300, 92) and the flare is 34Hz. Looks kinda fun but I fear my facility to bash through verifying matching driver and throat impedances is about 50 years in the rearview. You, of course, can just measure what's missing. If you have those dimensions from the cabinets, you can do Hornresp quickies w/o going "full-Olson".
Perhaps worth consideration is to photograph details of both the cabs and the original drivers as they'll not be made again and few are left. Learned only this week that the guy I was going to ask about those original drivers has now passed. AK might be a good place to post that stuff for posterity as well. If nothing else, the hole/cutout size and mounting (bolt-circle) info need to be known.
I don't think there's anything made now that can approach whatever the MI-4411 field-units did...different world/times. You might as well use anything from the sims I've done on the (slightly larger) Australian version--everything is rough (but that doesn't mean it can't make you smile). I might well be wrong--but at least the paper shows what he was trying to do and I didn't go through the work to try.
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@Technical Please send me a PM--I have some questions about the RCA speakers. I've been a member here since at least 2008, but for some reason, I'm unable to send you a message. 🤷♂️