Acoustic Control Corp 626 -any info out there?

So I have a problem with purchasing old speakers...
and this time they weren’t Polks... but I know there’s a lot of knowledg in this group so I figured I’d float some questions...
Today I was browsing the local thrift store and came across a heavy pair of old cabinets I’d never heard of. Acoustic Control Corp 626's for $10ea. Someone has kindly painted the walnut cabinets black and replaced the 12's (I find reference online that the originals may have been made by “Eminence”, one photo I found showed a square magnet) with some nasty (cheap) Realistic drivers. Is there anyone here familiar with the mfg? From what I find online, an older California based hi-if company (CSI) was purchased in the 70's by Acoustic, who built (and still builds) guitar amps and cabinets. I’d really like to find a pair of original drivers or, an equivalent set for when I douse the Realistics in gas and have a sacrificial burning to the Audio Gods....
Thoughts? Thanks all!
What they should look like (photo from Google search):

The cabinets I picked up which will be refinished and re-worked:


Today I was browsing the local thrift store and came across a heavy pair of old cabinets I’d never heard of. Acoustic Control Corp 626's for $10ea. Someone has kindly painted the walnut cabinets black and replaced the 12's (I find reference online that the originals may have been made by “Eminence”, one photo I found showed a square magnet) with some nasty (cheap) Realistic drivers. Is there anyone here familiar with the mfg? From what I find online, an older California based hi-if company (CSI) was purchased in the 70's by Acoustic, who built (and still builds) guitar amps and cabinets. I’d really like to find a pair of original drivers or, an equivalent set for when I douse the Realistics in gas and have a sacrificial burning to the Audio Gods....
Thoughts? Thanks all!
What they should look like (photo from Google search):

The cabinets I picked up which will be refinished and re-worked:

Upstairs 5.1.2:
Marantz NR1607
L/R - Modified Monitor 7C (194’s, Dynamat, Sonicaps, Mills, H-nuts)
Center - Yamaha NS-C310
Surrounds/height/Atmos - (4x) Proficient in-ceiling
Sub - RBH TS10AN
Marantz DV7600
Downstairs 5.1.4:
Marantz SR6011
B&K ST-1430 feeding L/R
L/R - SDA SRS 2, RTA12C (194's)
Center - RBH 700-CX
Surrounds - Monitor 5b (SL1000)
Height/Atmos - (4x) Polk RC60i
Sub - JBL 12” frankenspeaker
Samsung bluray
Office:
Cambridge Soundworks Amp
Monitor 4b (Peerless)
Spares:
Monitor 10a, Monitor 7b (Peerless), Monitor 5c
...and more to come, it’s a sickness.
Marantz NR1607
L/R - Modified Monitor 7C (194’s, Dynamat, Sonicaps, Mills, H-nuts)
Center - Yamaha NS-C310
Surrounds/height/Atmos - (4x) Proficient in-ceiling
Sub - RBH TS10AN
Marantz DV7600
Downstairs 5.1.4:
Marantz SR6011
B&K ST-1430 feeding L/R
L/R - SDA SRS 2, RTA12C (194's)
Center - RBH 700-CX
Surrounds - Monitor 5b (SL1000)
Height/Atmos - (4x) Polk RC60i
Sub - JBL 12” frankenspeaker
Samsung bluray
Office:
Cambridge Soundworks Amp
Monitor 4b (Peerless)
Spares:
Monitor 10a, Monitor 7b (Peerless), Monitor 5c
...and more to come, it’s a sickness.
Post edited by JayMX on
0
Comments
As to the MR and the woofer, check the back for EIA manufacturer codes if you can find any photographs of the original's innards. Or dig deep on other hifi fora. Eminence's EIA code was (and is) 67. CTS is 137. Those, I reckon, are the most likely suspects for something like these. The problem is that, even if the woofers were made by Eminence, they could have been any of dozens of 'standard' models, or it's just as likely they were bespoke (so to speak) OEM drivers made to the loudspeaker company's specification.
EIA codes (one of many sources): https://www.tedweber.com/speaker-codes-application/ (see also their link to more codes on that page!)
I will say (not that you asked) that I'm not seeing much there of interest -- although the boxes look well constructed. Per the reply immediately above -- it might be well worth repurposing the boxes with good, modern drivers and an appropriate XO design to make the most of what's there. One may calculate the volume of the box and the port volume to work out the tuning of the BR, and work backwards to identify a woofer with appropriate Thiele/Small parameters. The sensitivity of the chosen replacement woofer can be used to identify appropriate MR and tweeter drivers. www.partsexpress.com (and their speaker builder forum) and www.madisound.com are outstanding resources for loudspeaker DIY -- and there are others as well.
HTH, if only a wee bit.
"Some amps run on self bias, some amps run on fixed bias. But his amps run on confirmation bias." -- seen on audioasylum
Does that crossover "network" only consist of two capacitors and a pair of L-pads? Or are there also one or two inductors (coils) in there?
I can't tell for sure from the photo... if there are only two first order XO elements for the MR and tweeter, that's pretty... primitive... for a three-way.
"Some amps run on self bias, some amps run on fixed bias. But his amps run on confirmation bias." -- seen on audioasylum
As recommended above I'll do a little math and look into some new drivers. @mhardy6647 - yes, that's all the "crossover" consists of.
Fun project all around! I appreciate the insights.
Marantz NR1607
L/R - Modified Monitor 7C (194’s, Dynamat, Sonicaps, Mills, H-nuts)
Center - Yamaha NS-C310
Surrounds/height/Atmos - (4x) Proficient in-ceiling
Sub - RBH TS10AN
Marantz DV7600
Downstairs 5.1.4:
Marantz SR6011
B&K ST-1430 feeding L/R
L/R - SDA SRS 2, RTA12C (194's)
Center - RBH 700-CX
Surrounds - Monitor 5b (SL1000)
Height/Atmos - (4x) Polk RC60i
Sub - JBL 12” frankenspeaker
Samsung bluray
Office:
Cambridge Soundworks Amp
Monitor 4b (Peerless)
Spares:
Monitor 10a, Monitor 7b (Peerless), Monitor 5c
...and more to come, it’s a sickness.
Also I sanded one of the cabinet bottoms and oiled the walnut just to see how they are going to look. Sexy stuff under that old black paint...
Marantz NR1607
L/R - Modified Monitor 7C (194’s, Dynamat, Sonicaps, Mills, H-nuts)
Center - Yamaha NS-C310
Surrounds/height/Atmos - (4x) Proficient in-ceiling
Sub - RBH TS10AN
Marantz DV7600
Downstairs 5.1.4:
Marantz SR6011
B&K ST-1430 feeding L/R
L/R - SDA SRS 2, RTA12C (194's)
Center - RBH 700-CX
Surrounds - Monitor 5b (SL1000)
Height/Atmos - (4x) Polk RC60i
Sub - JBL 12” frankenspeaker
Samsung bluray
Office:
Cambridge Soundworks Amp
Monitor 4b (Peerless)
Spares:
Monitor 10a, Monitor 7b (Peerless), Monitor 5c
...and more to come, it’s a sickness.
What are the cab dimensions?
Marantz NR1607
L/R - Modified Monitor 7C (194’s, Dynamat, Sonicaps, Mills, H-nuts)
Center - Yamaha NS-C310
Surrounds/height/Atmos - (4x) Proficient in-ceiling
Sub - RBH TS10AN
Marantz DV7600
Downstairs 5.1.4:
Marantz SR6011
B&K ST-1430 feeding L/R
L/R - SDA SRS 2, RTA12C (194's)
Center - RBH 700-CX
Surrounds - Monitor 5b (SL1000)
Height/Atmos - (4x) Polk RC60i
Sub - JBL 12” frankenspeaker
Samsung bluray
Office:
Cambridge Soundworks Amp
Monitor 4b (Peerless)
Spares:
Monitor 10a, Monitor 7b (Peerless), Monitor 5c
...and more to come, it’s a sickness.
I'm with Festy, that port just looks odd.
Did the math: that port is tuned for 45Hz, definitely not low enough. You'll need to double the length to get into the mid 30s, elbow required. Or another option: make the port 2.75" in diameter and run the same length to get to the mid 30s
Marantz NR1607
L/R - Modified Monitor 7C (194’s, Dynamat, Sonicaps, Mills, H-nuts)
Center - Yamaha NS-C310
Surrounds/height/Atmos - (4x) Proficient in-ceiling
Sub - RBH TS10AN
Marantz DV7600
Downstairs 5.1.4:
Marantz SR6011
B&K ST-1430 feeding L/R
L/R - SDA SRS 2, RTA12C (194's)
Center - RBH 700-CX
Surrounds - Monitor 5b (SL1000)
Height/Atmos - (4x) Polk RC60i
Sub - JBL 12” frankenspeaker
Samsung bluray
Office:
Cambridge Soundworks Amp
Monitor 4b (Peerless)
Spares:
Monitor 10a, Monitor 7b (Peerless), Monitor 5c
...and more to come, it’s a sickness.
the woofers you "confirmed" were made the 9th week of 1980 (but you probably knew/figured that out already)
So 2200 in^3 = approx. 1.27 ft^3
-- and the ported enclosure is tuned to 45 Hz from the factory.
I am guessing (and this isn't a particularly educated guess!) that the Fs of the original woofer might have been ca. 60 Hz (i.e., a "pro sound" kind of driver)?
Looks like the sensitivity of that (4 ohm version? it should be marked on the magnet) of the Philips "world's worst dome tweeter"
So, you want a woofer with sensitivity in that neighborhood, too (although of course the MR & tweeter can be padded down a bit if need be).
Do you (the OP) know anything about the MR drivers?
"Some amps run on self bias, some amps run on fixed bias. But his amps run on confirmation bias." -- seen on audioasylum
The tweeters are actually Matsushita Heavy Industries (Panasonic) EAS-9KH05S. They’re 8ohm. The “grill” and front cover plate are a litttle different. However, the magnet and mounting plate for the soft dome/wiring wiring looks identical to the Phillips unit you referenced. So I’m sure they’re very similar... not sure who knocked who off first?
The MR's are a mystery as they’re sealed up in their little cardboard cocoons and I can’t find a way to extract them without damaging the mounting.
More sanding tonight revealed more beautiful walnut...
Marantz NR1607
L/R - Modified Monitor 7C (194’s, Dynamat, Sonicaps, Mills, H-nuts)
Center - Yamaha NS-C310
Surrounds/height/Atmos - (4x) Proficient in-ceiling
Sub - RBH TS10AN
Marantz DV7600
Downstairs 5.1.4:
Marantz SR6011
B&K ST-1430 feeding L/R
L/R - SDA SRS 2, RTA12C (194's)
Center - RBH 700-CX
Surrounds - Monitor 5b (SL1000)
Height/Atmos - (4x) Polk RC60i
Sub - JBL 12” frankenspeaker
Samsung bluray
Office:
Cambridge Soundworks Amp
Monitor 4b (Peerless)
Spares:
Monitor 10a, Monitor 7b (Peerless), Monitor 5c
...and more to come, it’s a sickness.
I looked at current 4 ohm Eminence drivers on Parts Express last night - but they're way more serious drivers than what you'd want to put in those little boxes; and they're also more expensive!
"Some amps run on self bias, some amps run on fixed bias. But his amps run on confirmation bias." -- seen on audioasylum
Marantz NR1607
L/R - Modified Monitor 7C (194’s, Dynamat, Sonicaps, Mills, H-nuts)
Center - Yamaha NS-C310
Surrounds/height/Atmos - (4x) Proficient in-ceiling
Sub - RBH TS10AN
Marantz DV7600
Downstairs 5.1.4:
Marantz SR6011
B&K ST-1430 feeding L/R
L/R - SDA SRS 2, RTA12C (194's)
Center - RBH 700-CX
Surrounds - Monitor 5b (SL1000)
Height/Atmos - (4x) Polk RC60i
Sub - JBL 12” frankenspeaker
Samsung bluray
Office:
Cambridge Soundworks Amp
Monitor 4b (Peerless)
Spares:
Monitor 10a, Monitor 7b (Peerless), Monitor 5c
...and more to come, it’s a sickness.
Even with the RadioShack 12's loaded in them they actually sound surprisingly warm and smooth. The L-Pads help to tame the tweeters. I think some 12's with white cones would look pretty cool in the cabinets. We'll see how much $$ I can justify dropping into them... I mapped out the crossover, which I may re-cap because it’s super simple. However, I may add a low pass filter for the woofer. The mids are crossed over at ~1.3K so maybe low pass at 500? Thoughts? Thanks again for all the input!
Marantz NR1607
L/R - Modified Monitor 7C (194’s, Dynamat, Sonicaps, Mills, H-nuts)
Center - Yamaha NS-C310
Surrounds/height/Atmos - (4x) Proficient in-ceiling
Sub - RBH TS10AN
Marantz DV7600
Downstairs 5.1.4:
Marantz SR6011
B&K ST-1430 feeding L/R
L/R - SDA SRS 2, RTA12C (194's)
Center - RBH 700-CX
Surrounds - Monitor 5b (SL1000)
Height/Atmos - (4x) Polk RC60i
Sub - JBL 12” frankenspeaker
Samsung bluray
Office:
Cambridge Soundworks Amp
Monitor 4b (Peerless)
Spares:
Monitor 10a, Monitor 7b (Peerless), Monitor 5c
...and more to come, it’s a sickness.
If (if!) you think you might have a go at this sort of thing again a few times, you might want to consider in investing in something like this:
https://www.parts-express.com/behringer-dcx2496-ultradrive-pro-digital-24-bit-96-khz-loudspeaker-management-system-cros--248-669
You'll need a couple of more amplifiers as well -- but you can play with crossover points & slopes easily.
There are also amplifiers with DSP and standalone DSPs that might be very useful in empirically optimizing XOs.
"Some amps run on self bias, some amps run on fixed bias. But his amps run on confirmation bias." -- seen on audioasylum
Marantz NR1607
L/R - Modified Monitor 7C (194’s, Dynamat, Sonicaps, Mills, H-nuts)
Center - Yamaha NS-C310
Surrounds/height/Atmos - (4x) Proficient in-ceiling
Sub - RBH TS10AN
Marantz DV7600
Downstairs 5.1.4:
Marantz SR6011
B&K ST-1430 feeding L/R
L/R - SDA SRS 2, RTA12C (194's)
Center - RBH 700-CX
Surrounds - Monitor 5b (SL1000)
Height/Atmos - (4x) Polk RC60i
Sub - JBL 12” frankenspeaker
Samsung bluray
Office:
Cambridge Soundworks Amp
Monitor 4b (Peerless)
Spares:
Monitor 10a, Monitor 7b (Peerless), Monitor 5c
...and more to come, it’s a sickness.
I've been inching towards doing the same thing with my Frankenaltecs.
"Some amps run on self bias, some amps run on fixed bias. But his amps run on confirmation bias." -- seen on audioasylum