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What used to be Rectilinear III Highboys

C

clang444

Active Member
So I found these locally for next to nothing:

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They used to be a pair of Rectilinear III Highboys but someone went and did a complete driver overhaul. They also decided to convert to a sealed cabinet.

Before I waste both his and my time by driving over and listening to them I thought I would ask here what people think. Could these sound good? The dome midrange with a 12" woofer has me thinking this may not have been a very well thought out mod, but I could be wrong...
 
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It is my opinion that the boxes are good for any large 2.7 cuft project
involving a new design. The original had small voice coils so they will
not take a lot of power - not a party speaker.
I have a pair of original woofers if you decide to go back anyway, in fact
I have two pair.
 
clang444 said:
So I found these locally for next to nothing
Click to expand...

Depends on what "nothing" means.
I have one restored set and one set where they changed all the drivers except the woofer.
I plan on making a new baffle and reusing the woofer. The original Jensen FlexAir woofer actually works better in a sealed box.
The FlexAir's are about 12 ohms so they're tube friendly. Who knows what are in the ones you're looking at.
The cabinets are actually very nice so if they are really cheap get them and then see what you can do with them.
The drivers in those don't look too terrible. Might need some work but what the heck.
 
I have some spare Norelco mid-ranges out of some wrecked Mini III's so I thought about using the FlexAir's, Norelco's and a more modern dome tweeter.
 
Good Ideas gents. I was thinking parts for a project as a potential fall back plan if I get them.
 
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That is not the stock woofer, so those three drivers may have come together as some sort of "kit" (or from a different speaker) designed to offer good full range performance with the proper cross-over network if the drivers are decent. I wouldn't consider touching those things unless you knew the driver brands and model numbers.
 
The front baffle comes off and it's an open book for working on. REALLY good cabinet for single full range speakers. Everything I've put in them has worked well.
Even the 12 inch whizzer cone E/V LS12a was a winner. Very good for acoustic and solo voices.
If you've not heard the full range magic this is a good place to start. Cut a new baffle board, drop in one of the usual suspects. Next month try another flavor.
 
I will preface this post with letting you know I am a real nube when it comes to electronics and speaker design. I'm handy with wood and metal and enjoy learning new stuff. I also love the sound of classic speakers with 10" or 12" woofers.

Working from home has me bored to death so I picked these speakers up as a potential project. I figured the cabinets were worth their cost in firewood if nothing else. One of the speakers sounded OK, but the other one did was not as bright and was missing some of midrange. Base was OK but not great on both speakers. All the drivers worked so I figured it was an issue with the crossover. I took the speakers apart and here is what I found:

The guy must have been a Parts Express customer. New components were:
Dayton Audio DC300-8 12" woofer 8 Ohm with
Peerless 821639 2" Poly Dome Midrange 4 Ohm
JAMO 20134 1" Soft Dome Tweeter 8 Ohm

The original crossover was bypassed and a new one was added. I have no idea what type or the crossover frequencies.

The woofers have jumpers with capacitors inline, no idea what for.

The original Rectilinear tweeters and super-tweeters are still on the baffle, but the guy who redid these speakers coated them with silicon caulk. He must have been a real silicon caulk fan because the new tweeters and mids were also glued in with the stuff.

I tried to free one up one of the original tweeters and it damaged the diaphragm and ripped off the dust cap off. I'm guessing these are destined for the scrap heap unless someone thinks there is a reason to salvage them.

So my big question is: What to do with them? I could make new baffles from MDF and properly mount the drivers that came with them. I could replace some/all of the drivers or I can supplement them with an extra mid or tweeter (or both). I can go either sealed or front ported. Crossover repair or replacement is going to have to happen too.

So what do you guys think? Do I have enough lemons here to make lemonade? I'd prefer to keep the project low cost, so bang for the buck is an important consideration. I'm no speaker design wizard, so any knowledge sharing would be much appreciated.

The cabinets are in excellent condition. I can get them looking better than new with a light sanding then a few coats of tung oil. I will also probably pull the original terminal plate/crossover and replace with something better.

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Make a new baffle, reuse your woofer and tweeter and build this in one box:
https://sites.google.com/site/undefinition/tarkus
Tweeter as high as possible with provision to replace with the correct one later,
then mid close to it, then woofer also close. Cut the brace out if you have to.
Buy the correct mids, they are only $20 each, you can probably sell your domes for that price.
Tune the box to 32 Hz.
Build a box to seal off the mid.

I expect that you will be shocked by how good they sound.

Confirm that your woofers and tweeters are working first.
 
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I think we'd need some idea of your budget to give you suitable recommendations. Lots of options depending on what your taste in speakers and how many $$$ you want to spend.
 
I like the description for the target sound of the Tarkus project Pete B linked to. I'm definitely the type of listener that appreciates a studio album over most live performances.

As for budget, the less the better. This is a learning experience for me, I don't expect perfection, but I'm just hoping for something I enjoy listening to.

After doing some more research I see I am jumping into the deep end of the pool. I'll come back after doing more research with more specific questions about the details of the project as they come up.
 
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I would say that the "bang for buck" solution would be to use the woofer you have and make an "Econowave". The DC300-8 is not great but not bad and you could change it out later if you like what you hear but want more. The horns and drivers will be about $130 plus shipping. the crossover is harder to guesstimate because you might be able to reuse some of the bits that are in there already.

The Econowave project has acquired a life of its own and there are volumes written about it. In your particular case, the originator of the Econowave, Zilch, has already done a crossover for the DC300-8. Sadly, Zilch is no longer with us but thanks to the internet he's still "sort of" here. Here it is....

http://techtalk.parts-express.com/forum/tech-talk-forum/34467-flex-your-pcd-mettle/page2#post457498

post #20

Interestingly enough my current project is turning some nice cabinets with crap drivers I found cheap at Goodwill into Econowaves.
I will be making the HPM-100 variation with those great old woofers and some new horns. My cabinets are just a bit smaller than the Rectilinear IIIs but are very similar. I'm at the 'make a new baffle" stage. I'm saving my III cabinets for a semi-modern remake of the original as I said back in post #6.

PeteB is also making some Econowaves in a Rectilinear III cabinet but with other drivers.
 

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Thanks - I was looking at the Econowave info but thought a 12" woofer might be too big for a 2 way speaker. I will look into it more.
 
Altec Voice Of The Theaters and larger JBL systems used 15" drivers for bass and lower midrange so 12" is fine. Having said that it, using a 12" or 15" in a 2 way does require a pretty decent driver.

The larger BBC monitors also used 12" woofers.
 
clang444 said:
I like the description for the target sound of the Tarkus project Pete B linked to. I'm definitely the type of listener that appreciates a studio album over most live performances.

As for budget, the less the better. This is a learning experience for me, I don't expect perfection, but I'm just hoping for something I enjoy listening to.

After doing some more research I see I am jumping into the deep end of the pool. I'll come back after doing more research with more specific questions about the details of the project as they come up.
Click to expand...

I'd do that project unless you really want to do an Econowave.
 
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