'Ohmm' P212. Rip off of Ohm speakers or genuine vintage?

[UncleK]

Please scroll to the bottom of my post for pics.

I have just bought the pair for a price which I am willing to disclose if anyone can tell me the value of these

I googled the hell out of them and could not find an identical speaker at all. Seller claims they are from the 70s and were used as PA Loudspeakers for a gospel band throughout the 80s, so the drivers may be worn IDK,

I am a little suspicious of the logo and name 'Ohmm' spelt with 2 m's as opposed to the Ohm Amplification brand. Although the styling of the text looks very similar. Could the Chinese have been ripping off speakers this early on?

From what I can see, the model number is P212 and they appear to take mono jacks input. Passive dual concentric 2 x 12" cones.

One of the drivers is non functional but this could be an internal crossover board issue and potentially very easy to fix.

Either that or I've just paid for 2 lumps of junk

So guys, experts and fanatics, can you enlighten me with any info about these speakers and their value in their condition and if they were in a working state?

They are 100W a piece.

All advice appreciated.

Thanks!

 

[swechsler]

These are definitely PA speakers, I can't imagine that they'd be good for hifi sound reproduction. Ohm loudspeakers was founded in 1972; these look like they could be from the 1960s. Since they look like they're just two full range drivers per cabinet, I doubt there are any crossovers inside.

 

[Pioneered]

https://www.adverts.ie/other-dj-equipment/vintage-ohm-cabinet-speaker/10291210

 

[gdmoore28]

Definitely ProSound-style speakers. That means that they likely used as 1. Portable PA speakers/monitors, 2. Guitar cabinets, or 3. (least likely) keyboard monitors.

I wonder if one of the woofers in each cabinet is a co-axial unit with the horn firing through the dome?

GeeDeeEmm

 

[UncleK]

Kind of good news as I intend to use them for a smaller PA setup for our band when we are required to take our own PA. Not sure about those connectors until I pull them apart.

The seller told me the drivers are all in good physical so if they don't have an internal crossover then most likely a wire has corroded to the cone.

I was just more curious about why one 'Ohm' had added an extra 'M' onto their logo back then.

If they are 60's then are they likely to be worn out drivers?

Thanks for all the responses guys

 

[UncleK]

Definitely ProSound-style speakers. That means that they likely used as 1. Portable PA speakers/monitors, 2. Guitar cabinets, or 3. (least likely) keyboard monitors.

I wonder if one of the woofers in each cabinet is a co-axial unit with the horn firing through the dome?

GeeDeeEmm

I use a 4x12 Bass cabinet for my bass gig. It weighs 65 Kilos and can be drag when porting it around places like London. Would one of these be able to be used as a Bass cab too do you think? Obviously it would be very primitive solution as my current cab has a central tweeter also for a little high end bite. I could imagine if it worked, a precision bass might sound very nice through them.

Also what do you mean by the woofers in each cab being co axial firing through the dome?

Thanks

Kieran

 

[gdmoore28]

Also what do you mean by the woofers in each cab being co axial firing through the dome?

Thanks

Kieran

I was simply wondering out loud. But I've seen systems specifically made for PA use in which one of the drivers is coaxial. A coaxial speaker is one in which a high frequency "tweeter" is incorporated into a woofer in order to provide a wider frequency response. One such design has a horn driver either attached to the back of the woofer magnet or built into the woofer magnet. The hi frequency horn output is directed to the front of the woofer through the center of the voice coil. Like this:

It's highly unlikely that this is the case with your speakers, but it would not hurt anything to look inside and check it out.

As to whether these would be appropriate for your bass guitar, there are simply too many variables at play to allow a definitive answer: are the speakers powerful enough for bass reproduction? How loudly do you expect to play? Is the "voicing" of these speakers appropriate for bass guitar? In short - I don't know!

It would be interesting to see what is inside these cabinets. If you take a look inside, be sure to post some pictures for us.

GeeDeeEmm

 

[UncleK]

I was simply wondering out loud. But I've seen systems specifically made for PA use in which one of the drivers is coaxial. A coaxial speaker is one in which a high frequency "tweeter" is incorporated into a woofer in order to provide a wider frequency response. One such design has a horn driver either attached to the back of the woofer magnet or built into the woofer magnet. The hi frequency horn output is directed to the front of the woofer through the center of the voice coil. Like this:

It's highly unlikely that this is the case with your speakers, but it would not hurt anything to look inside and check it out.

As to whether these would be appropriate for your bass guitar, there are simply too many variables at play to allow a definitive answer: are the speakers powerful enough for bass reproduction? How loudly do you expect to play? Is the "voicing" of these speakers appropriate for bass guitar? In short - I don't know!

It would be interesting to see what is inside these cabinets. If you take a look inside, be sure to post some pictures for us.

GeeDeeEmm

Definitely going to be tearing down to look inside these first thing, so I'll do a reccie and put up some pics. I normally use a 250 Watt amp head driving a 600w Watt cab, so I guess maybe if I managed to split the output somehow across the two speakers then I wouldn't blow them up. Also the output of my amp is mono so would I need a DA to feed into both drivers? That's if each driver is with a coaxial config input of course.

 

[swechsler]

Not sure what you mean by a DA, but if you try to run both of these off a mono amp you may run into low impedance issues. I can't read the speaker impedance off the plate in your first pic. Is it legible? If so, what is it? Remember that if you daisy chain from the first speaker to the second (or if you connect both speakers to the same outputs) you'll be connecting them in parallel, which means the impedance that your amp sees will be halved (so for example, if the speakers are 8Ω each, when you connect both, your amp will see a load of 4Ω). You probably won't want to connect them in series, since then if one cabinet fails, you'll have no sound at all. One potential solution would be to rewire the cabinets so the drivers are wired in series internally, then you could connect the cabinets in parallel (that's assuming that both drivers in each cabinet are identical, which we haven't yet established). But before you make any changes, first check the speaker's impedance, then check the amp's manual to see the minimum it can handle.

 

[UncleK]

Not sure what you mean by a DA, but if you try to run both of these off a mono amp you may run into low impedance issues. I can't read the speaker impedance off the plate in your first pic. Is it legible? If so, what is it? Remember that if you daisy chain from the first speaker to the second (or if you connect both speakers to the same outputs) you'll be connecting them in parallel, which means the impedance that your amp sees will be halved (so for example, if the speakers are 8Ω each, when you connect both, your amp will see a load of 4Ω). You probably won't want to connect them in series, since then if one cabinet fails, you'll have no sound at all. One potential solution would be to rewire the cabinets so the drivers are wired in series internally, then you could connect the cabinets in parallel (that's assuming that both drivers in each cabinet are identical, which we haven't yet established). But before you make any changes, first check the speaker's impedance, then check the amp's manual to see the minimum it can handle.

Cheers for the advice, I will add more info when i receive them!

 

[UncleK]

DA is a distribution amplifier - IE it duplicates the signal rather than splitting the gain and causing the impedance issues you mentioned.

This way I would also have redundancy with the cabinets. Besides the Cabs are for on stage monitoring and normally the Sound Tech will take a balanced DI from the back of my amp head anyway,

 

[toxcrusadr]

Never seen Ohmm before but the others have it nailed. Probably not an earlier version of the Ohm company. I don't think Ohm made PA gear anyway.