Old-timey 8" 3-way in the works...

jr@mac

Sooooo... after much bargain hunting, I now have the drivers (or I will, when the woofers ship) for an old-timey 8" based 3-way.

Woofer: MCM Audio Select 55-1240. I picked this one because it has advertised parameters that indicate it will work in a true "acoustic suspension" alignment, has a groovy old-timey clear poly cone (looking at you, 80's Infinity), and is obviously 8" in diameter. It also has a little more throw than typical 8" woofers in this price range. Not a lot of choices for drivers that look old fashioned out there, these days. I considered using a pair of Dayton Audio 8" Classics - but they have weird parameters. They will not dig at all deep in a sealed alignment, and going vented violates the spirit of the project - plus they require a dorm fridge for an enclosure. They look right - but, come on...



Midrange: Foster 095M1301. 1-1/2" dome, non-chambered mid. Big rectangular faceplate. Voice coil terminated in a visible manner (wires stick out). Beautiful old school midrange with 800 Hz FS. Found them on Fleabay pretty cheap:



http://www.ebay.com/itm/231268049005?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT

Other than the guy using a HiVi graph (lol), pretty legit. Cheap, too. 

Tweeter: (high probability anyways, unless some other beauty of an old-timey looking tweeter comes my way) Silver Flute (distributed my MCM, NLA, 53-1060) 3/4" dome. Square faceplate. Fits the "look" I am going for. 



I hope the mids are more or less linear on-axis to at least 4.5K...

Stay tuned.

jr@mac

http://m.ebay.com/itm/2pcs-Philips-3X3-5-Dome-Tweeter-Made-in-Belgium-/251020596882?hash=item3a71fe5692:m:m1lLxSvWhrdB3Oozmk31NEg&_trkparms=pageci%3A04c9dd7d-e1bf-11e6-9f18-74dbd180cfc7%7Cparentrq%3Acd8a7a3b1590a2a4f8635c38ffb721cd%7Ciid%3A13

Never mind, just found these. More better for this build. 

PWRRYD

Interesting project JR.  Keep the posts/pics coming.

isaeagle4031

I am digging this big time!

jr@mac

These are going in my dads shop, he needs new speakers. 

squamishdroc

No school like the old school!

ScottS

This looks promising for a fun, cost effective throwback project.  It reminds me of a couple of things I need to get to...

jr@mac

http://www.ebay.com/itm/CULVER-8-WOOFER-WITH-PAPER-CONE-AND-CLOTH-SURROUND-35W-RMS-AT-8OHM-NOS-/331615735929?hash=item4d35d69079:g:xIIAAOSwMmBVt-ew

Look what else the guy selling the mids has... wish I had seen them earlier!

jr@mac

Normally I do not engage in stuff like "I am going to cross at X and X" until I get measurements - but I am hoping to pull off a 1200/4800 design out of this. With luck, and perhaps by ignoring modern rules, I hope to be able to do so with extremely few components.

I also have some L-pads, those might be fun to mount on the front panel. 

jr@mac

Something like this is what I am thinking...

Any interest in a retro-themed event? No contests, nothing like that - just build something that looks like it was designed prior to, say... 1990?

Mitchell_Cote

For what it is worth I would like to see it!  No time to do build though.  

Mzisserson

Got all 4 of my 55-1240's  in today. One thing about MCM's cheap metal frames. They ain't so cheap. They at least rigid enough to not torque with a little twist of the wrist, and I dont fear bending them to death around the screw holes when I mount them. 

Man, the look takea me back. 

Going to get them doing the dance of our people and measure soon. 

I need to scour local thrift shoppes and goodwills once I spec out a cab. It would be cool to sure-up and retrofit an old cab with these. 

isaeagle4031

I certainly like the idea and have a great pair (actually like 3 or 4 pairs) of mid 80s to early 

Nicholas_23

jr@mac said:

Normally I do not engage in stuff like "I am going to cross at X and X" until I get measurements - but I am hoping to pull off a 1200/4800 design out of this. With luck, and perhaps by ignoring modern rules, I hope to be able to do so with extremely few components.

I also have some L-pads, those might be fun to mount on the front panel. 

+1 for attenuators

Mzisserson

jr@mac said:

Normally I do not engage in stuff like "I am going to cross at X and X" until I get measurements - but I am hoping to pull off a 1200/4800 design out of this. With luck, and perhaps by ignoring modern rules, I hope to be able to do so with extremely few components.

I also have some L-pads, those might be fun to mount on the front panel. 

I am guessing youare counting on a lot of 80's-90's drivers (even dome tweets) were designed for loooooooong shallow slopes? 

I am going to use my quad with the 3/4" MCM paper tweet. Thinking of what to flank it with. I should start a new thread, sorry for the parallel, just excited for the 55-1240s.

S7910

Cool project JR. I really like the idea of the L-pads for the full "retro" feel.

A retro-themed event would be awesome!

jr@mac

Mzisserson said:

jr@mac said:

Normally I do not engage in stuff like "I am going to cross at X and X" until I get measurements - but I am hoping to pull off a 1200/4800 design out of this. With luck, and perhaps by ignoring modern rules, I hope to be able to do so with extremely few components.

I also have some L-pads, those might be fun to mount on the front panel. 

I am guessing youare counting on a lot of 80's-90's drivers (even dome tweets) were designed for loooooooong shallow slopes? 

I am going to use my quad with the 3/4" MCM paper tweet. Thinking of what to flank it with. I should start a new thread, sorry for the parallel, just excited for the 55-1240s.

I am not afraid to add components to hammer them into submission (I have shelves full of caps, coils, and resistors) but yeah - the idea is to hit true 2nd LR between each driver. 

PWRRYD

jr@mac I am not afraid to add components to hammer them into submission (I have shelves full of caps, coils, and resistors) but yeah - the idea is to hit true 2nd LR between each driver. 

You sound like Ben there a little lol

Nicholas_23

  

kennyk

PWRRYD said:

jr@mac I am not afraid to add components to hammer them into submission (I have shelves full of caps, coils, and resistors) but yeah - the idea is to hit true 2nd LR between each driver. 

You sound like Ben there a little lol

Only if it is a series xo.

isaeagle4031

Ahhhh damn

jr@mac

Nah - just because I am not afraid of a lot of components doesn't mean I go out of my way to do so. 

Mzisserson

jr@mac said:

Nah - just because I am not afraid of a lot of components doesn't mean I go out of my way to do so. 

As long as it sims ok, you will be fine. Just make sure you filter EVERYTHING so its +/- 0.001dB. Only way speakers sound good you know. 

ScottS

Of course we won't really know if they sound good without a few rounds of double blind testing.  

jr@mac

These are destined to go in my dads shop, so... he has hearing aids but I plan on voicing them pretty forward regardless. 

Bryan@MAC

jr@mac said:

These are destined to go in my dads shop, so... he has hearing aids but I plan on voicing them pretty forward regardless. 

You know I have a fuckton of XO parts.  Let me know if you need something weird...I might just have it.  And yeah....about hammering drivers into submission I'm pretty sure that's what CJD has done a few times and his designs are not too shabby, IMO.  I say go for it.  

jr@mac

Man - I have a thousand parts sitting around, and it seems like I am always unwinding coils or paralleling capacitors to get the value I require. Crazy!

If I come across a value I need, I will reach out.

jr@mac

Tweeter flange is thicker than the midrange flange, so will require some thought on how I want to deal with that. Otherwise, next step is building some cabinets. 

6thplanet

Prolly gonna need some dancing lights inside the cab, that clear cone is begging for it !

jr@mac

So I am not sure the clear poly woofer will work for this application, and am looking at alternatives at the moment. 

I really like the 80's look the poly woofer offered, but it is too high Q for where these are going to end up, which is on the wall in my dads shop. He don't need no 1.5 cubic foot boombox up there. 

I digress.

What I really dig are those old timey untreated paper cones and foam surrounds. Drivers like the Bose 301 use are absolute eye candy to me sometimes, not too common to find affordable paper cone drivers without that cheap looking "poly" coating on them, though. 

Visaton sells an 8" untreated paper cone, foam surround driver - but at the price point ($30) I can do better performance wise - it is only a couple bucks less than the 8" KB from MCM, that is ridiculous IMNSHO. 

I continue in my quest. 

Actually, the 8" KB would be just fine, the larger KB have an old timey look to them. 

Mzisserson

I have a quad of 55-1190s on their way from MCM for an unrelated comissioned project, though these seem better suited for an AS enclosure. I plan on getting them measured if you want to hang for the t/s.

No promise they will be acceptable... Hope they are!