Curbed CBS Audio Products Reference: 312 L

Well, okay they weren't actually Curbed. A very long-time friend gifted them to me to refurb and sell. I used the "Curbed" more of a note to let people perusing this portion of the Speaker forum to know who it was starting this thread. He's the original owner and bought them new from Pacific Stereo eons ago.

This is one of the many instances where the term Rare is defined as not many around and not much information readily available on them. I don't believe Rare can be used to describe how valuable they are. From the few references posted here, we've determined that they're of an exceptionally sturdy build, 1" MDF. Design? Components? I dunno, but from what I remember and what others have said the sound is mediocre at best. I just weighed them, 49.6 pounds a piece at 32" tall.

For me, it's more about putting them back in to service and giving them the same respect as my Wreckedilinears and new find, the JBL L26's. They've made it this far and deserve a woofer refoam and recap. Oh yeah, and a thorough cleaning! There's no reason they cannot be used in someone's garage, dorm room or do outside duty at parties when needed. Besides, this will be my first refoam job and I'd rather practice on these drivers versus the JBL 125A's in the L26's. Agreed?

I yanked one to pieces and took some pictures. If someone recognizes the drivers, that'd be nice. Otherwise, I'll take some time and see if I can't find those online raw speaker references I keep hearing about.

Here are some pictures for those who may be interested!

















xo, Biggles

You're gonna be busy now with 2 projects! Or did you finish the JBLs?

Ttech said:

You're gonna be busy now with 2 projects! Or did you finish the JBLs?

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Ha, nope. If I had finished them, all yalls would have been the first to know. They're safely tucked away, awaiting 2 replacement woofers. I haven't found the money yet, maybe this pair will fund the JBL's. That would be nice, eh?

Biggles

Sturdy looking magnets on those drivers.

Dr. Biggles To The Rescue?

Hi drbiggles!

I hope you don’t mind me dragging up this thread, but I have a pair of the 312Ls. The woofers were replaced with a pair of Carbonneau CG-308-Rs. which are pretty darn good. They have 2” coil, 38 OZ magnets, carbon-fiber cones, and an Xmax of 6.1 MM.
The trouble is, I do not have any idea what the wiring should be to go to the drivers from the crossover. The tweeters were Polydax, and I still have the midranges.
In short, do you remember which wire goes where? Any help would be great. They are such great boxes, and as you know they were designed for 1st order crossovers, with the baffle tilt. There is also a 10” version, which look like their little brothers.

those polydax tweeters are quite good. back in the day you could buy replacement Voice coil dome assemblies making them repairable not replaceable. still have a pair around here somewhere.

drbiggles, can you give me some advice on this, or a schematic or something?
Thank you.

Hi Dave!

I really apologize for not responding earlier. Apparently, I didn't set up an auto thingy to tell me when someone posted here. I just happen to wander past this morning and thought to myself, "Hey, don't I have a pair of those somewheres?". Once I opened up the thread, I realized that it was mine. Egads.

I don't have a schematic. But we can work through it. I tore into one enclosure, but the other one is untouched. We should be able to figure out which wires go to the woofer within a few minutes.

However, I couldn't possibly be any busier today and thankfully have some work tomorrow. I will make an attempt tonight and tomorrow after work to get some idea as to what wires go to which driver for you. Will pictures of the wires connected to the original drivers work for you?

Biggles

Hey, I noticed that in one of the images I first posted you can see the driver holes with wires hanging out. Yellow, green and orange. If you look hard, one of each has a black stripe, the orange ones go to the woofer. Does this help?

Biggles

No Problemo!

drbiggles said:

Hey, I noticed that in one of the images I first posted you can see the driver holes with wires hanging out. Yellow, green and orange. If you look hard, one of each has a black stripe, the orange ones go to the woofer. Does this help?

Biggles

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Thanks for answering drbiggles. I figured you would get to it. I THINK I'll be able to get it from that shot, except for the phase, but I might be able to figure that out also. I saw that shot, but I didn't really LOOK at it, so that's fantastic. They are nicely sorted out through the holes.
Any ideas you have, but only WHEN YOU HAVE TIME, because I don't want to be a pain. LOL
Man, they were THIS CLOSE to making an excellent speaker. I figured a stiffer rolloff on the bass, and mids would have improve it a lot, but you know these companies: If they can save a dollar on a cap, or an inductor, they will. It's much harder to build a cabinet like that with the angles, so IDK why they just didn't put a few more bucks in to it. I would reverse engineer the crossover, and try to improve it, but LEAP and LMS are boat-anchors right now.

I should have looked closer at that one! Thanks again.

Hey mang,

Remember, you're always welcome to PM me. I'm on here everyday, most all day. But I haven't been working on projects and/or paying close attention to much. But PM's pop up immediately.

As far as phase goes, I can still poke my head into one. But these are tucked in the far back of my speaker storage area. Thankfully, over the last month and a half I've completely cleaned and rearranged it. So, it shouldn't be all that tough, really. I even found a wall that I've set up a listening wall. This way when I'm working on or testing speakers, I can have a decent area to test them in. Before I was standing 12" from them, hunkering down. Not optimum.

In any case, am really happy to help out where I can. I will still pull the woofer and check the phase, see where the black stripped wire is connected to. It's not that big of a deal.

The enclosures are really solid, very thick particle board. But other than that, I have no clue as to how well their actually designed. At least it has a crossover, not sure how well it does what it does. I can say the plastic framed grill covers have gotten really wonky warpy and I'm not convinced I can do anything with them. I'd have to make new ones and I surely won't go that direction. My plan is to refoam the woofers, recap the crossovers and sell them for anything I can get. I need to thin the herd so I can get more, more of what I'm more interested in.

Biggles

Hey Dave!

I wanted to stop by and let you know I've made a few attempts at checking the polarity. It's not going well and I would just throw caution to the wind and guess. They're way back, buried. And, I've drug home a free 300 pound steel and formica workbench. Am attempting to shoe-horn it into my workspace.

Biggles