Ohm C2 Service Work

[3M_Audio 2,020]

Had a good friend from our church that knows I run a speaker manufacturing business, so he asked me to help him with his stereo system which he described as 'sounding thin'. He had a nice silver-faced Onkyo receiver and some beautiful Ohm C2 speakers. The C2s are a 10" ported design and were marketed by Ohm as a bookshelf speaker. After about 2 seconds of listening, I told him what the problem was.  

 

 

I'll probably service the crossover at the same time I have the woofer out. Should be a fun project.

 

I have listened to these before and they have a nice, warm sound. Not the best imaging, but OK. They need lots of power.

 

[BobTFM35 2,767]

It looks VERY free floating.

 

I would think with new foam or rubber surrounds plus new modern caps it will sound much better.

 

Looks like a fun project!!

[3M_Audio 2,020]

Just now, BobTFM35 said:

It looks VERY free floating.

 

I would think with new foam or rubber surrounds plus new modern caps it will sound much better.

 

Looks like a fun project!!

 

It's surprising how many speaker owners never remove the grills from their speakers. The guy that owns these bought them new in 1979 and he never was curious enough to take a look.

 

These are fun to do although to do it right, all the old adhesive needs to be removed from the basket before installing the new surround.

These use an inverted foam surround. Quality replacements and adhesives are available from Springfield Speaker - a good small company.

 

My friend was interested in the process, so I'm planning to shoot a video of this one. I'll post a link here once finished.

[BobTFM35 2,767]

I had a set of speakers that I bought when I was in Japan. 

 

For all the places they traveled and the action they endured they looked pretty good when I took them out of the cabinet for the first time in their life. The recapping gave them a new life as I'm sure it will do the same for his set.

 

 

[3M_Audio 2,020]

For any of you following along. My friend decided to have me replace the (3) caps in the crossover so that's done:

 

 

And the new surround is glued into place. Most of the work is scraping off the old adhesive on the basket frame - it has to be perfectly clean. I find that with most of these speakers from the late 70s and onward, the spider holds the voice coil into proper position with only very minor positioning required, so shimming isn't necessary.

 

Edited January 23 by 3M_Audio
typos

[AndrewJohn 10,441]

4 hours ago, 3M_Audio said:

For any of you following along. My friend decided to have me replace the (3) caps in the crossover so that's done:

 

 

And the new surround is glued into place. Most of the work is scraping off the old adhesive on the basket frame - it has to be perfectly clean. I find that with most of these speakers from the late 70s and onward, the spider holds the voice coil into proper position with only very minor positioning required, so shimming isn't necessary.

 

 

Where do you get those clamps?  

[BobTFM35 2,767]

Harbor freight?

https://www.harborfreight.com/hand-tools/clamps-vises/spring-clamps/spring-clamp-set-22-piece-69374.html

[3M_Audio 2,020]

2 hours ago, BobTFM35 said:

Harbor freight?

https://www.harborfreight.com/hand-tools/clamps-vises/spring-clamps/spring-clamp-set-22-piece-69374.html

 

Bing!

[3M_Audio 2,020]

Finished and sounds pretty nice. Beautiful cabinets - real walnut veneer even behind the grill cloth. I think if these were mine, I'd leave the grills off and remove the velcro.

 

I'll shoot some video of the second speakers to share. Owner has me doing one at a time so he can still listen to something

 

[Rob 5,974]

I have had the L’s, L2’s, Cam Pro, K’s. In my opinion the L2’s were the best. When doing the surrounds I used a CD  with a 30 hz frequency which plays for 3 minutes. You can spread the glue and let it get tacky then turn on the CD and start to adhere the surround to the frame. It will rattle if it’s off center. You can just push it around to eliminate the rattling. 
Good job restoring these. They look to be in very good condition. Worth the money to upgrade. 

Edited January 30 by Rob

[3M_Audio 2,020]

I finally put together a 10-minute video of the restoration work on these. I'd appreciate everyone's feedback - too short, too long, too much info, not enough info, etc. 

 

 

 

 

[Walrus Gumboot 370]

Very well done on the video...thanks for providing it.

[Half Life 601]

Thanks for posting the video!  Awesome tips, tricks and best practices!  I've never attempted a repair like this but watching this have given me the confidence to try it.  I've held onto a pair of Coral BX-33's my Dad bought in Japan in the early 70's.  I've always wanted to restore them and now I will.  Appreciate the "kick in the pants"!

[AndrewJohn 10,441]

What is the genesis of "Ortus Solis?"  I'm curious.

 

You have the voice for Pod Casts..., or more videos. 😉 

 

And the vibraphone music..., love it!

 

 

[3M_Audio 2,020]

8 minutes ago, AndrewJohn said:

What is the genesis of "Ortus Solis?"  I'm curious.

 

You have the voice for Pod Casts..., or more videos. 😉 

 

Latin for 'New Day' or 'New Life' - what I'm trying to give some of these old pieces of equipment.

 

As to the voice, many, many years ago I was in broadcast radio - until I learned that it didn't pay any money, lol. But I'll be doing more videos - that Golden Hour clock I picked up may be next.

[Rob 5,974]

Great informative video. 

[Dadvw 2,876]

On 1/23/2025 at 6:54 AM, 3M_Audio said:

For any of you following along. My friend decided to have me replace the (3) caps in the crossover so that's done:

 

 

And the new surround is glued into place. Most of the work is scraping off the old adhesive on the basket frame - it has to be perfectly clean. I find that with most of these speakers from the late 70s and onward, the spider holds the voice coil into proper position with only very minor positioning required, so shimming isn't necessary.

 

Oh Look, A OhmFlower...........ROTFLMBO