Rectilinear 7 - Free Empty Enclosures, an Audio Adventure

[ra.ra]

Just thought to mention that more excellent Rectilinear chatter can be found thru the link shown below. Since one of my main interests is AR speakers, I tend to give attention to the site for New England speakers.

http://www.classicspeakerpages.net/IP.Board/index.php?showforum=29

 

[kirk57]

YEAH !!! I think I can deal with the midranges. If I remember correctly, someone posted in the Early Rectilinear thread about a really nice, modern drop-in replacement.

That might have been me, talking about this.

I put them in my Highboys and no doubt they are a nice improvement in detail over the Philips, which are no slouches.

 

[michiganpat]

if you wanted to go a different direction, watch the AK design collaborative 3 way speaker development. cutout the baffle and replace with a new one, and these are about the perfect size for the speaker they're looking at developing

 

[drbiggles]

Just thought to mention that more excellent Rectilinear chatter can be found thru the link shown below. Since one of my main interests is AR speakers, I tend to give attention to the site for New England speakers.

http://www.classicspeakerpages.net/IP.Board/index.php?showforum=29

Noted! Will have a gander later on tonight.

That might have been me, talking about this.

I put them in my Highboys and no doubt they are a nice improvement in detail over the Philips, which are no slouches.

It was! I searched and searched last night, finally found your reference in my bookmark file. THAT's exactly what I was looking for.

It was right then I measured my hole at 6.5" (edge of flange, not actual hole, I think), a tad larger than the 3.75" baffle cutout requirement.

Am considering making an MDF adapter for them. I got a router.

if you wanted to go a different direction, watch the AK design collaborative 3 way speaker development. cutout the baffle and replace with a new one, and these are about the perfect size for the speaker they're looking at developing

Thank you, I'll take a look over there later on tonight. I'll have some time to myself after dinner.

Am down to 1 small part time job, low on cash. Need to pinch every penny, hey. Remember, whatever route I choose today, can be changed in the future. Nothing is written in stone, and no modifications will be permanent. If something isn't right, or I get some better/nicer parts, I can swap them in without issue.

Here are some images of drivers that will be headed my way soon. I do not have them yet.

As you can see, they're shabby. But all drivers test good on the ohm's meter, so there's that. Any thoughts to possible tweeter repair? I've done woofer repair with Aleen's and tissue, used some rubber cement in the past. What ya'll thinkin'?

xo, Biggles

 

[GD70]

Hey mang,

I'd probably stick with the tissue paper rubber cement approach with the tweeters as well since you had success before.

Glenn

 

[drbiggles]

Hey mang,

I'd probably stick with the tissue paper rubber cement approach with the tweeters as well since you had success before.

Glenn

I did and repairs still solid. Gotcha.

Until the drivers get here, can clean the pots and order/install new capacitors. Am going to do the Vinegar Bath option.

Biggles

 

[GD70]

I did and repairs still solid. Gotcha.

Until the drivers get here, can clean the pots and order/install new capacitors. Am going to do the Vinegar Bath option.

Biggles

After the vinegar bath, wash and rinse with soap and water throughly.
I'd like to see some before and after cleaning pics. Curious what shape the wipers and disks are in.

You should also do a sweep with the meter to both extremes and watch that the meter reads smooth. If I remember correctly, at the extremes it should read around +-15 ohms. At least that's for the AR's. May be a different spec for your speakers.

Glenn

 

[doctorolds]

...Here are some images of drivers that will be headed my way soon. I do not have them yet.

As you can see, they're shabby. But all drivers test good on the ohm's meter, so there's that. Any thoughts to possible tweeter repair? I've done woofer repair with Aleen's and tissue, used some rubber cement in the past. What ya'll thinkin'?

xo, Biggles

It looks like you will have 1 Jensen (220) and 1 CTS (137) woofer based on the pictures, if I am not mistaken. They should sound fine since the build specs would have been the same Do you have a close-up of the tweeter needing repair?

 

[drbiggles]

After the vinegar bath, wash and rinse with soap and water throughly.
I'd like to see some before and after cleaning pics. Curious what shape the wipers and disks are in.

You should also do a sweep with the meter to both extremes and watch that the meter reads smooth. If I remember correctly, at the extremes it should read around +-15 ohms. At least that's for the AR's. May be a different spec for your speakers.

Glenn

Understood and can do. I like pictures. Considering the shape of the speakers, I would think they'd be pretty rough. Except these pots aren't designed to be moved by the end user. Factory set, and forget. We'll see how that goes, eh?

Biggles

 

[drbiggles]

It looks like you will have 1 Jensen (220) and 1 CTS (137) woofer based on the pictures, if I am not mistaken. They should sound fine since the build specs would have been the same Do you have a close-up of the tweeter needing repair?

That's what it looks like to me, but from the front they both look like Jensen.

Nope, these are all the images I have at the moment. From the looks of the tweeters, they all have issues!

Biggles

 

[doctorolds]

... Except these pots aren't designed to be moved by the end user. Factory set, and forget. We'll see how that goes, eh?
Biggles

Just red paint holding them in place. When you take them apart just remove the paint and lube the shaft and set them to where you like just as the others function. The only other way would be to replace with a resistor.

 

[ra.ra]

This is turning into my kind of salvage project --- half a coat hanger, one of those things, a couple of them doo-hickeys, a handful of this, a roll of duct tape, and some spit.

Glenn is correct to advise giving the cleaned pots a dry-run meter check before re-installing, and it never even occurred to me that these pots may have a different resistance range from those found in the old AR's, but now that I think about it again, I'm betting that these are fully identical. AR used the exact same pots in their 4 ohm and 8 ohm models and Biggles' frankenspeakers will probably end up with resemblance to both the R-III (8 ohm) and the R-7 (6 ohm). However, I've cleaned a bunch of these old pots and I've never seen any that just need a bath and fresh undies - - - mine have always also required some elbow grease as well as some abrasive scrub-a-dub.

Those drivers shown in post 44 look just fine to me - - in fact, I'm not sure which is the damaged tweet. The woofers look terrific, and it appears you'll already have one mid, two tweets and three super tweets. All of the tweeties look like the R-III version, but can't tell which octagonal Phillips mid driver you show - - is it the smaller R-III or the larger R-7?

Found this document of interest (possibly not even pertinent).

 

[39cross]

All of the tweeties look like the R-III version, but can't tell which octagonal Phillips mid driver you show - - is it the smaller R-III or the larger R-7?

The Phillips mid is from a R-III highboy, one of the earlier incarnations judging by both the cross over and the square tweets that were mounted on the baffle board.

 

[KentFJ]

Pot cleaning

If they are like Rec III very easy here is picture of all the parts

https://www.flickr.com/photos/17611327@N04/15581302106/

good luck with restore. my eyes n ears are looking 4 some for Me

 

[drbiggles]

Just red paint holding them in place. When you take them apart just remove the paint and lube the shaft and set them to where you like just as the others function. The only other way would be to replace with a resistor.

Yup, and maybe at some point put in pots with shafts so I can put knobs on there. That's what I was thinking.

This is turning into my kind of salvage project --- half a coat hanger, one of those things, a couple of them doo-hickeys, a handful of this, a roll of duct tape, and some spit.

Glenn is correct to advise giving the cleaned pots a dry-run meter check before re-installing, and it never even occurred to me that these pots may have a different resistance range from those found in the old AR's, but now that I think about it again, I'm betting that these are fully identical. AR used the exact same pots in their 4 ohm and 8 ohm models and Biggles' frankenspeakers will probably end up with resemblance to both the R-III (8 ohm) and the R-7 (6 ohm). However, I've cleaned a bunch of these old pots and I've never seen any that just need a bath and fresh undies - - - mine have always also required some elbow grease as well as some abrasive scrub-a-dub.

Those drivers shown in post 44 look just fine to me - - in fact, I'm not sure which is the damaged tweet. The woofers look terrific, and it appears you'll already have one mid, two tweets and three super tweets. All of the tweeties look like the R-III version, but can't tell which octagonal Phillips mid driver you show - - is it the smaller R-III or the larger R-7?

Found this document of interest (possibly not even pertinent).

Interesting attachment, will read it further in a bit. I agree on the project, bits and pieces, spit and gum. Pulling new drivers out of a box, with new crossover parts and new enclosures doesn't inspire me. I want old bits!

Biggles

 

[drbiggles]

If they are like Rec III very easy here is picture of all the parts

https://www.flickr.com/photos/17611327@N04/15581302106/

good luck with restore. my eyes n ears are looking 4 some for Me

The 7's are a different beast. There are similarities, especially at first glance. At least that's what I've found so far. Good luck on your search, the III's are more than worth your time and effort. Hooyah!

Biggles

 

[KentFJ]

the III's are more than worth your time and effort. Hooyah!

Yeah I rebuilt my buddies ...hated to give them back and now you have me looking at them all... like 25 + pairs of speakers in the house is not enough.
Thinking time to thin the heard but what would I connect all the receivers 2 :lmao:

 

[drbiggles]

Yeah I rebuilt my buddies ...hated to give them back and now you have me looking at them all... like 25 + pairs of speakers in the house is not enough.
Thinking time to thin the heard but what would I connect all the receivers 2 :lmao:

Tired of hearing about thinning the herd. I figure, if I lose inspiration on a pair, they can go. But if I want them, I will make room for them and keep them. I need more receivers and amps. Then, I'll need more speakers.

Biggles

 

[drbiggles]

Happy Sunday,

Yeehaw! The driver packaged arrived yesterday, opened them up this morning. Best Christmas present, ever.

I haven't tested the drivers yet, super preliminary. The woofers are exact, and perfect drop-in replacements. Even the mounting holes match up. I will not be using the stock wood screws to mount them though. I would like to try my hand at installing t-nuts and see how that goes. Wood screws and 40 year old particle board may have been an acceptable solution back then. But after some time, things get a bit flaky, eh?

One of the tweeter's paper cone isn't repairable, too huge of a rip/tear. Another has an inch long rip/gouge laterally along the surround. I'll play with that and see what I can do. This isn't an issue, the tweeters were known to be shabby and am glad to have them all.

The midrange driver and tweeters are clearly larger than the existing holes. Am going to try my hand at using my new plunge router and hole jig to make adapters. I've only used a router twice in my life, and that was to try a bit I'd just purchased for the Wharfedale Super 12 project. I think with a good game plan, practice and patience I should be able to make them. Thankfully the recessed holes are at least a 1/4". This will be perfect for the 1/4" MDF stock I have on hand!

I have a question though, may figure it out on my own. The cup that protects the midrange from the woofer's backlash is at least twice as large as the III's deli cup. Not sure what the older midrange will sound like with a larger enclosure. Am still considering the modern replacement for the III's midrange driver. Will still have to make an adapter plate for that one too.

I have not removed/cleaned the pots, yet. I will remove the capacitors from the circuit and test. I want to find out if I can put this all together to see how it sounds before I buy new capacitors. Once everything is all put together and working, then I figure I can mess with the guts and enclosure and whatever else would need doing to fine tune.

Biggles

 

[kirk57]

The crossover points of the 7 are 200, 1800 and 10k. If you use those Peerless tweeters with the existing crossover and run them down to 1800 I fear Bad Things may happen. (Recall they cross @3k in the model III).

The Philips mid should be OK down to 200.