Earth Sound Research 2x12 specs?

[BassDaddySky]

Picked up this groovy little sealed cab from FB marketplace last night.
Dude was using it with a 100w guitar amp.
But I understand the ESR amps and cabs could be used for bass.

And I am wondering what the specs might be, so I can match it with an appropriate bass amp.
The jack ohms out at 17.3 ohms
So they are probably 8 ohm speakers in series, but what wattage can they handle?

Here are some pics to help you help me

 

[agedhorse]

I wouldn’t put more than 100 watts into that cabinet for bass guitar… very limited power handling.

 

[Mike Caldwell]

Those speakers look like they have treated paper surrounds, yes be careful, not sure if the voice coil would catch fire first or the surrounds
would tear. I would leave them wired in series.
1976 Oaktron speakers.

 

[JamesGrant]

Bass - I’d be amazed if you’d put 50W RMS at 50Hz into those speakers and they survived for any length of time! Might be super with a little 25W tube bass amp - studio-style bass rig, certainly not going to be hifi, but for a low volume, lo fi vintage vibe I bet it’d be sweet!

 

[RicoTheBassMan]

Dude! I had an Earth Sound Research tube head that deserves to be in a museum! I did not have the original cabinet so I can't speak to the speaker spec. ESR was generally copying other popular gear selling in the 70's. If you aren't looking for a scientific approach, do an AI search using a picture of the amp and see what comes up. You will most likely find some Ampeg or Fender gear that looks very similar that has the same specs.

Fun stuff!

 

[braud357]

The Earth cabinets were Peavey clones. Your 2x12 cabinet looks exactly like the 2x12 Peavey PA speakers I owned back in the 1970's. We had originally bought them to use as midrange cabs for our PA. I noticed that they did not have the usual speakers in them when we purchased them, and upon inspection we discovered that the heavy duty CTS guitar speakers had been installed at the factory. One day at practice I played bass through them and it sounded GREAT. I commandeered them and used 2 of them for my bass rig for almost 3 years. I do not think that it would last very long using your present speakers for bass. I pushed mine with an old Peavey 300 slant front PA head and never blew a speaker.

 

[BassDaddySky]

Probably not gonna even try it for bass then. I could use the speakers in a guitar combo i have maybe.
Just as a thought. What higher wattage speakers would be appropriatefor a smaller (1.82 ft³ ) sealed cab like this?
Minimum 200 watts, as the "smallest" head i own atm is rated 180w @ 8ohm

 

[agedhorse]

Small sealed cabinet… not a great option for bass IME.

 

[BassDaddySky]

Ok, so i did some math
And decided to find a pair of 10" speakers to match the volume available with this box.
FB marketplace saved the day with some very affordable used Hartke aluminum cones!

Made some 12 to 10 adaptors out of 5 gallon ABS bucket lids. Just for a proof of concept.
Thought they would be abit floppy but they are surprisingly stiff, what with all the little cast in ribs around the perimeter.
Probably gonna paint 'em aluminum silver.
If they seem stable, all I'll have to order are some dust caps.


Also glad I opened the cab all the way up, because the wiring was pure crap.
Cold solder, chunk of cut extention cord, coupled with some 18g wire!


Do you guys think I should add some fluf type damping to the back wall while i have everything done apart?

 

[agedhorse]

The driver in the picture is hammered. Nothings going to matter as those drivers weren’t designed for a sealed box.

 

[BassDaddySky]

Not doubting you at all AH,
Just trying to learn.
What do you see that tells you the driver is toast?

And I thought the Hartke aluminum 2x10s were sealed cabs, no?

 

[agedhorse]

Not doubting you at all AH,
Just trying to learn.
What do you see that tells you the driver is toast?

And I thought the Hartke aluminum 2x10s were sealed cabs, no?

The obliterated dust cap for one thing.

There may be some models that are sealed, but the older ones I am familiar with were slot ported.

 

[Michedelic]

No one seems to know exactly the how, why, or when, but Earth Research was a transition from Plush amplifiers, who initially emerging around ‘68 from the NYC area, eventually moving to south of LA. These were the amps that looked similar to Kustom, but had an entirely different ‘tuck and roll’ design(with corresponding cabs), and more importantly, were tube-based rather than Kustom’s solid state. In fact, Plush heads internally were knock-offs of Fender Showman designs, with a little front end tweaking to accommodate guitar, bass, and PA differences. They had a few larger 6550/KT-88 heads, I don’t know about those, perhaps pilfered from Sunn designs, but after the brand name change, initially everything was identical(with the padded finish), then came the Peavey clones, solid state, and slightly off imitations of Fender tweeds(which Peavey was doing as well)and kinda-like Sunn gear, but with 6L6 tubes instead their customary KT-88. The company disappeared into the night by the mid-70’s.

I think you have a halfway serviceable, if not quirky, guitar cab, based on an old Peavey PA cab.

 

[BassDaddySky]

Sounds great at 3/4 Volume
Out of the tube side of the Kustom TRB400!
@ 8ohms it should be getting 200w max.
Db isn't there Like with the 2-15 behind it. But its clear and punchy.
Fun little one day, under 100 dollar project.
Ill try it with my Peavey Centurion next.
And I threw the "guitar" 12s into a Line 6 combo I has that was missing it's speakers
Just gotta sacrifice a speaker cable to wire it up.