Altec 12/15 'alternative'...

I really dig the mid-century flair of your cabinets. Also, really enjoy the use of SP-12's. Ive been curious about them for years, and thought they'd be fun to play with - sans those old Karlson cab configs.

My friend's father had built a pair in the 60's, (like so many others) and later when he bought AR3a's, well you know. Last I heard, my friend still has them in his basement. Along with the Eico amp he built to power them.

Nice work!

*Edit typo SP-12...

So far the Sp12-Bs are surprising me. They are nicely sensitive and seem to be good performers. I will say that I believe I have a very, very, very nice pair that sure seem like they have 'low mileage' on them.

Thank you, I like their look as well. I borrowed heavily from @je2a3 posts on his blog about his Emilar bowtie adventures.

Hope it's ok to link to it from here:

(Re)building a Hi-Fi Room

If I build a 'fancy' set of cabinets for these, I would use the same walnut plywood I used to build a friend a big desk and bookshelves. Trim it in solid walnut. Or even maple ply with thick solid walnut trim..... hmm...
 
So, I'm starting to think I need to write down some plans for testing, otherwise I'll get lost down one particular path and miss out on testing more thoroughly. ... I know myself well enough by now :D

To that end, I'm going to barf a rough list here. Please speak up with any insights, commentary, etc. I'm thinking of a few phases of testing/measuring tweaking:

1 - Individual driver, enclosure measurements.

2 - Crossover point testing, per slope, ie:

1200hZ first order
1800hz first order
2000hZ first order

1200hZ second order......

3 - Box tweaking (rear panels, stuffing/insulation)

Off the cuff it seems 1 will help lead me to 2, which should lead me to 3 being minor 'tweaks' mostly.

I'm sure I'll spend more time thinking about this than I need to, so, I better get to it!
 
Looking forward to what you rig up for the horns.

Dont think I posted a closeup of the 'mount'. I basically am using 2 pieces of bamboo cutting board glued together, with an ~1/8" thick piece of cork on the bottom, then a ~1/16th" thick strip of neoprene directly under the compression driver.

The horns two lower bolt holes mount into a pair of M6 ez-locks. I used a chunk of ~1/8" (3mm) neoprene to prevent rattling. I have a selection of M6 bolts on hand, and some material to make spacers with, so I can easily move the horn forward when/if need be.

I'll post some detail pics of that when I get to that point.
 
Great job on the cabs! Have fun tweaking. 🍻

Thank you sir, so far I'm having a great time!

You're to blame for all of it, haha. I wouldn't have bought the horns, which started this journey, were it not for your blog entries on the Emilar gear. I never would have tried these horns/drivers had I not read about them.

They're not 1" Altec alnico deliciousness, but they are impressing me so far. :D
 
I'm listening to them now, with the same set of tracks I've been using to evaluate them. I have them crossed ~1800hZ first order, and I am liking this a great deal more than ~1200hZ.

Early to say with certainty, but this feels like a step in the right direction.

Tracks/sources:

Chan Chan - Buena Vista Social Club - CD
My Favorite Things - Coltrane - CD
Dangerous Type - The Cars - Vinyl
The Falconist - High on Fire - CD
Liability - Lorde - CD
Orion - Metallica - Vinyl
Unchained - Van Halen - CD
H - Tool - CD

edit: added a few more tracks to the rotation
 
Last edited:
Added the second rear panel, and a bit of poly batting. The batting is very loosely, and partially covering the only open area on the rear panel.

This has helped clean up the bass a good bit, the bass was a bit loose and 'boomy' previously.

I'm going to leave things here and listen to a broader selection before the next move.

I need to debug why rew won't start on Fedora 28, so I can take some measurements. I'll deal with that tomorrow.

IMG_1534.jpg
 
Spent several hours listening, both focused and as background. My dad is staying with me this weekend, he's the primary reason I've spent a lifetime being obsessed with music, so naturally, we're spending a lot of time listening to music.

No changes since last night, and I'm still really liking this current iteration. There is a great, somewhat laid back perhaps, 'hifi' fun feel to the system. I'll probably connect my 45 amp to it tomorrow, likely not quite powerful enough for the living room, but who knows.
 
So, during the listening sessions I noticed a bit of 'muddiness' that I was attributing to the crossover and LF cabinet tuning. After more tweaking and listening I started investigating the autoformer wiring to ensure I hadn't screwed something up.

Well.....

I screwed something up.

I hadn't tied the '0' terminal (ground/common) to the ground/common of the crossover. This has an odd affect, some quick by ear testing shows that it appears to modify the frequency response somewhat, and attenuation level. I'm not certain how this works, and would really like to know. I may do some actual measurements at some point to see if I can figure it out. The end result is that the systems sounds significantly better now :D

The number of clip leads continues to increase.......

IMG_1540.jpg
 

Thermionics

Post Whore In Training
Made awesome progress today:

Cut baffles and rear panels to final size, I will likely cut the rear panels into 3 pieces and test the drivers with various combinations of no rear panel, to partial rear, etc.

Mounted the feet, installed the CLD material, put finish on the baffles and main cabinets. Marked all the mounting locations for the baffles, I'll drill those out tomorrow or Wednesday.

Figured out the mounting distance for the horn and compression driver, and a few other little details.

Yes, that is the worlds best beer, in the shot for scale with the CLD material. One of the best at least.... Hitachino Nest White Ale, it is so, so, so damn tasty. Speaking of the CLD material, I normally use vinyl floor tile adhesive to mount the CLD material. It has an adhesive backing, but I've just normally used the floor tile adhesive. I couldn't find it in the shop today, so I didn't use any. I know several other people who only use the adhesive it comes with and haven't had any issues, so hopefully my experience will be the same.

Once I mount the baffles, I'll put in the denim insulation on the side, top and bottom panels. I may put some ~1/2" felt on the baffle, we'll see.

The project is on schedule rather well, so far. I am really enjoying this build, and hoping that the flexibility I've built into the projects works out as well.

The baffle cut-out and mounting bolt holes should work for both the Electro-Voice SP-12B's, and the Bozak B-199-A's. My plan is to listen to both sets of drivers, at 2-3 crossover points each and decide what I like best. I will most likely do some in room measuring as well. I have a umik and REW setup, and plan to employ this to tune the stuffing, rear panels, etc. for the LF cabinets.

That's the general plan at least. If I have them prepped in time, I'll have Wednesday night, all day Thursday and a good bit of Friday to measure, listen, and enjoy them. No kids in the house, wife will be out of town and I'm off work. I would call it the perfect storm, but that would lead to something getting in the way and screwing it all up for me. So I'll just call it a few days of sleeping too little, forgetting to eat, and god willing, getting lost in my music collection for several days.

You should feel sorry for our animals, which for sake of inventory is:
Salty - smelly, medium sized female Australian Cattle Dog.
Joker - grumpy, loud mouthed, tiny ball of anger, male Chihuahua mixed with napalm and back alley mutt.
MuMu - sweet old lady cat, long hair, but shaved into a 'lion' cut for summer. Because it's >100 damn degrees here for what feels like 2 years every year.
Viva - aka 'Dicky Spanish' - jerk head, loud, pushy, Russian blue and alley cat mix. She's unreasonably attached to me. I love cats, but good lord, she's more needy than my junior high girlfriend was.
Davis - aka 'Dave' - Norwegian fancy rat, he's awesome. We got him for our youngest daughter, but I fell in love with him. He's very social, and has giant balls.

Then there are my two outside cats, strays, that I've adopted. Yes, I'm that sucker. My family calls me the cat lady. I might have bought 2 insulated, pressure sensitive, heated cat houses for them. Then.... built houses to hold the houses, with cedar strip floors to keep the bugs out.

Sarsaparilla - aka 'sassy' - the first stray I adopted. She's tough, but sweet, the mockingbirds do not seem to like her. Of course, mockingbirds are jerks.

Xeda - Solid black, and I mean solid black male cat. He's been slowly getting more used to me, I think I can catch him soon to get him fixed, microchipped, etc. I think he beats up raccoons for fun.

I know, I'm a sucker for animals. I've even named the 2 main raccoons that come and eat what the two outdoor cats leave behind. They're both jerks, for the record.

ok, enough rambling, on to the all the pics:

View attachment 13781View attachment 13782View attachment 13783View attachment 13784View attachment 13785View attachment 13786View attachment 13787View attachment 13788View attachment 13789View attachment 13790View attachment 13791
What feet are you using with those cabinets? I'm thinking about doing something similar with my Altec 614-755 cabinets (yet to be revealed to the world).
 
The legs are Ikea, 'Capita'. You can get them on Amazon, and likely Ikea, as well as other places. I've had them in a drawer for a few years from some other project. Whenever we go to Ikea I try to dig around for little items like this that I can use. I have several different sets of legs, these looked the coolest I thought.
 

Thermionics

Post Whore In Training
The legs are Ikea, 'Capita'. You can get them on Amazon, and likely Ikea, as well as other places. I've had them in a drawer for a few years from some other project. Whenever we go to Ikea I try to dig around for little items like this that I can use. I have several different sets of legs, these looked the coolest I thought.
@gable - I thought I recognized them! I use them under my Kallax record storage shelves! :)
 
Great build adventure
Some how I missed this till today.
Really great cabinet work.
I love speaker builds )

Thank you! I'm quite pleased with the cabinets.

I just finished putting new cork gaskets on the Bozak B-199-A's that I picked up recently. Hopefully I'll get some time soon to try those out.
 
I still haven't put the B199a's in as yet, but I did make one change today that I've been wanting to do for awhile. I brought my SE 45 amp from the office to the living room and hooked it up. I'm amazed at how damn loud it can get. We have a very, very large living room, >600sq ft, with coffered ceilings over 12'. 2 watts of kickassery has me playing vinyl and cd's left and right all night.

Now, on really heavy material it runs out of steam towards the top of the volume knob, but not my too much.

Some of the playlist has included:
Fugazi
Unsane
High on Fire
Coltrane
Metallica
The Kinks
Lorde
Johnny Cash
The Beastie Boys
Thelonius Monk

and many others....

maybe I do need to build a 'big' single ended triode like a 2a3 ... move up to ~3 watts

or a gm70 maybe, I have a bunch of ~1kv rated gear, chokes, caps, an enormous vintage, potted UTC power trans, 1000v @250mA or maybe 300mA, would have to look.

I also have a nice stash of overkill rectifiers, 872a's ....

so many ideas, so little time...



IMG_1625 (1).jpg
 
Top