Rock Partners

[jason4300]

http://washingtondc.craigslist.org/nva/ele/5758796913.html

So these popped up on CL, about 45 minutes from me. Listed at $40, I could probably talk them down to $30. I haven't found much info, but what little I have found suggests that they are basically an AR18b and are regarded as a good speaker. Looking at the pics, it would seem the surrounds are intact/possibly new and it sounds like a simple crossover, if I would have to rebuild. Assuming there would be minimal work needed with these, are they worth 30-40 bucks and a drive?

[amanteyzapata]

I've seen those but never heard them…Guessing they beat Bose hands down and would make a great garage/workshop speaker.  I'm probably the wrong person to ask since my wife allowed me to put my AR90s in our garage to accompany the stuff I do.  I know, a slight insult but not really.  I use them often so they get my respect.  Still, those look small enough to hang up high and feel good.  Your call!

[michiganpat]

yes...essentially tonegen versions of the 18S/B drivers.  sound like them, too....xover is a simple cap, 5uf, same as the S and B.  I have a pair, and ended up putting the drivers in some advent prodigy cabinets with the recapped RP "crossover" since one of the grilles was all bent up....they're run by a Marantz 2230 in my 9 year old daughters room and sound pretty much the same as the 18's that were on it before (and are now on my 6 year old son's stereo)

[jason4300]

That's a nice setup for your daughter. I had a Marantz 2230 a few years back that powered a set of AR228's and I regret to this day selling.

 

Having experience with the 18b, what are your thoughts on it?

[michiganpat]

I don't have experience with the B, just the original 18 and the rock partners....like them both.....I also have had some Holographic Imaging M5's (regret selling), 2ax's (were OK, but not overwhelming) 312HO's (in our home theater, great speakers from the recoton era AR of the late 90's), and some 58S's, which I need more time with but like so far....

 

[jason4300]

Thanks for your feedback. I think I'm going to try and pick these up. The seller says he's having health problems and doesn't seem too interested in selling right now unfortunately.

12 hours ago, michiganpat said:

 312HO's (in our home theater, great speakers from the recoton era AR of the late 90's

 

Ive got their little brothers, the 206HO's as the rears in my home theater. Very nice speaker. That era is very underated imo. My mains are a set of 318PS' and matching center, also from the late 90's. All together, it's a very nice sounding setup.

[jason4300]

So, the fe-mailman dropped off a set of these on my doorstep today. I found another set after the CL seller flaked on me. I immediately opened them up and swapped the 30 year old NPE cap out for a 4.7uf Carli cap and a couple of NOS PIO caps that totaled 5uf. The original caps both read 5.6uf on my meter. I hooked them up and A/B'd them with my 94si pair. They don't have much of a low end, but the highs and mids are quite nice. They do a good job of pointing out how lacking the mids on the 94's are. Unfortunately, after 10 minutes of listening, I blew half of the seemingly good foam surrounds out, so I won't be able to give these a thorough listen until I order some surrounds. In the meantime, they have a nice home on my stack of project speakers.

[lARrybody]

Congratulations on your rock partners. New foams are not that hard. The cleaning of the old surround residue is the worst part. Yesterday I too picked up a second pair of rock partners. The first pair turned out to have Bose replacement woofers. The recent woofers appear to be correct. Do yours look like this one?

[jason4300]

37 minutes ago, larrybody said:

Congratulations on your rock partners. New foams are not that hard. The cleaning of the old surround residue is the worst part. Yesterday I too picked up a second pair of rock partners. The first pair turned out to have Bose replacement woofers. The recent woofers appear to be correct. Do yours look like this one?

Yep, they're 37's and the tweeters are 38's. What surrounds did you use on yours?

 

[lARrybody]

I just pulled these out tonight. They have the surrounds they came with. They don't appear deteriorated, but I have not played them yet. They will be going into some AR25's which came to me with Radio Shack replacements. I will probably replace the surrounds. There are two good choices (1) Boston 8 in. filled fillet type surrounds and (2) JBL type 8 in. surrounds.  The JBL type are available several places, but I get mine from Rick Cobb (part number 610-365). rcobb@tampabay.rr.com   He probably has the Boston FF type also, which may be the better of the two performance wise.

[ra.ra]

I recently re-foamed these same woofers which were Tonegen factory replacements for a pair of AR-7's, and I used the Bose 301 surrounds recommended by Roy C. The Boston foams may be a bit more compliant, but the Bose is a better fit and a very suitable surround. Easy install, but that weird dust cap is a delicate process to re-attach if you use shims. Has anyone else encountered this elastic ring along the inner surround crease? It felt like a thin bead of silicone, and it peeled off with ease. I suspect that its original purpose was to create a profile similar to the Boston filled fillet regarding sound wave diffraction. 

[jason4300]

Mine appear to have that same rubber ring.I wouldn't have noticed it if you didn't mention it.

When you cut your dustcap, did you cut where the crease is, or where it's glued to the cone? I was going to attempt this with a 50hz sine wave playing through the woofer, but may just shim.

[adam2434]

Guys, I just refoamed AR18s woofers and removed the dustcaps completely, started with an Exacto knife, and peeled them away from the original adhesive with a tweezers.  I did not have to cut them, and was able to reglue them intact.  The dustcaps are rubber and did not permanently deform in the removal process.

Not sure if the RP woofers would allow this, but just wanted to throw this out there.  As an AR refoaming newbie, take this with a grain of salt.

 

[jason4300]

I started putting new surrounds tonight. Ordered these:

http://www.ebay.com/itm/360748750099?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

They're the same surrounds I use on my 94s with good results and it's hard to argue with the price. These ended up matching the dimensions of the original surrounds closely and were close to the thickness as well. I use a 50hz test tone instead of shimming. It seems these woofers are very forgiving as you could move the cone a good bit before you'd hear it hit the VC. I think I'd be pretty confident just doing surrounds on these without shims or a test tone. I finished one speaker before calling it a night. Hopefully i can get these wrapped up tomorrow and give them a thorough listen...

[WRamsey]

On 9/12/2016 at 4:28 PM, jason4300 said:

I started putting new surrounds tonight. Ordered these:

http://www.ebay.com/itm/360748750099?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

They're the same surrounds I use on my 94s with good results and it's hard to argue with the price. These ended up matching the dimensions of the original surrounds closely and were close to the thickness as well. I use a 50hz test tone instead of shimming. It seems these woofers are very forgiving as you could move the cone a good bit before you'd hear it hit the VC. I think I'd be pretty confident just doing surrounds on these without shims or a test tone. I finished one speaker before calling it a night. Hopefully i can get these wrapped up tomorrow and give them a thorough listen...

You just saved me , This thread was agreat find, scored these speakers on the side of the road being thrown out, Now I know the subwoofer just needs new foam, 

[Giorgio AR]

On 9/10/2016 at 3:38 AM, ra.ra said:

I recently re-foamed these same woofers which were Tonegen factory replacements for a pair of AR-7's, and I used the Bose 301 surrounds recommended by Roy C. The Boston foams may be a bit more compliant, but the Bose is a better fit and a very suitable surround. Easy install, but that weird dust cap is a delicate process to re-attach if you use shims. Has anyone else encountered this elastic ring along the inner surround crease? It felt like a thin bead of silicone, and it peeled off with ease. I suspect that its original purpose was to create a profile similar to the Boston filled fillet regarding sound wave diffraction. 

Hi Ra.ra, I also found in another post the presence of this "rubber / silicone ring" inside the foam roll of a 200001 speaker, signaling to have noticed it also in other woofers both 8 ", 10" and 12 ", in fact we note in numerous AR3a woofers on the original degraded foams (not present in those already refoamed).
Tunedguy57 (probably the greatest Italian HiFi expert and technician of unquestionable ability!) Interviewed by me some time ago, had given me a logical explanation of which I do not remember and I find no trace, surely the aim was not to weigh down the cone as I thought .
We hope for a definitive explanation of the purpose of this additional ring by a technician of the time and the material from which it is composed to restore our speakers as originally.

Giorgio

[Giorgio AR]

Ra.ra, I found my old post, including the Tunedguy! Response, below the post.

 

[ra.ra]

Hi Giorgio, I'll gladly add my thoughts, but this rubbery "ring" is still something of a mystery to me. Last time I recall it being discussed here, one member more correctly referred to this elastic substance as being more like rubber cement, whereas I had originally mischaracterized it as silicone-like.

Nevertheless, on both drawings for the 200001 and 200037 woofers, a substance titled "treatment" is shown in a detail where the foam surround laps over the cone. This material is not specified in either parts list on those drawings, but it is interesting to see it located below this juncture on the 037 woofer (left), but on the 001 woofer (right) it shows up on top.   

In either location, it certainly adds some small measure of weight to the moving cone assembly, but I cannot address any of the issues raised by Tunedguy, where he mentions: automated assembly process; dynamic shock; and break-up phenomena.