Bozak B302A Econowaves

[Andyman]

All set up and playing on the Keggerized 8802 and sounding quite nice. They certainly aren't as efficient as the Altecs, but the sound certainly is intriguing enough for a long term listen.

I added a set of 5 way terminal cups from a parted set of JBLs so I can swap between amps and speakers easily, so I anticipate a lot of mixing and matching. And I may be looking into more smartphone RTAs to see if I can find one I can print from, or at least export spectra from so I can post them here.

 

[Tom Brennan]

Interesting project and one that makes a great deal of sense to me.

 

[jackwoz]

cool thread ! thanks for posting.

 

[doucanoe]

I applaud your efforts Andy! There is nothing willy nilly about it if you know and understand the drivers you are working with along with crossover and box design/interaction. Crossover does not need to be unnecessarily complex. Particularly if you understand the driver characteristics and limitations and don't require horn compensation.

I'm currently working on a nifty DIY that revolves Bozak B199's and some lesser ALtec full range drivers. If they were not such a sensitivity/efficiency miss-match, I'd be trying them [199's] with my Altec multicell horn project. You can run them up pretty high and they sound nice doing so.


RC

 

[djnagle]

Here is my Altec rig. You never saw these Andy, I had them before SMAC. These are A7 cabs with the 515 woofer which in that cab was really only good to 80hz or so. The horns are 1505 sectorials with two 288C compression drivers per horn. The needed upper end help so I added the Beyma CP25 super tweeter between the cabs and the horns. The corner cabs are subs I added to bring up the lower end. After all the big azz speakers I've had over the years, these where the best!!!

 

[Andyman]

Sweet stuff Dennis! those horns really are impressive. But you may be right about the Altecs,as they seem to be vanquishing all comers here.

I finally got the crossover set to spec on the Bozaks by adding a .33 mH coil from a scrap crossover and i'm liking the sound a LOT. But, I still think the Altecs win the battle, at least right now. I do have to admit that the extra bottom does take some getting used to as it just wasn't there in the last several mains I've had down here and the fullness is a bit new to process.

This weekend I plan on doing a couple more tweaks. I was going to mount a horn in the cab, but I may just flip the cab upside down as that should effectively accomplish two things. First the desired reduction of the distance between driver centers, which is about 18" now to a more workable 10"-12", and second, raise the woofer off the ground more and closer to the height of the A7. I think the overall height of the A7s and specifically the voice coils, adds to the air and imaging of the system.

 

[lico]

Nice work. Getting the compression driver higher off the floor more makes sense to me, some tall legs on the 302s will help.

Fellow Ewaver here - #36. My 302s cabs never had any zak drivers to start with, so it was an easy decision to try something else. My Ewaves are the best speakers I own, listen to them daily.

 

[madmonda]

Nice work...and great determination! I'm patiently waiting for the outcome and some instructions (then, one day i'll get my ratty bozaks up and running again). Seems like it's a fun and fullfilling project for ya. Wish i could rap my head around custom creating and tweaking crossover networks.

 

[Gang-Twanger]

The corner cabs are subs I added to bring up the lower end. After all the big azz speakers I've had over the years, these where the best!!!

Those corner cabs are beautiful. What were they originally? What brand? They remind me of the woofer section of the big Wharfedale corner speakers (The top section with the mid and tweeter sat on top... I have a pair of the woofer cabs... 9 cubic feet of displacement... The cabs you have must be at least 6cu.ft., so you must be getting nice bass performance out of them... Is there a vent somewhere, or are those sealed?).

 

[djnagle]

They were built by a parisianer who was a professional cabinet maker. They are not that big. Only 2 cu ft inside. the walls are 1.5" thick doubled up plywood and they came with the 12" Coaxial Stromberg-Carlson driver. I think it was called the 400 Wide Range driver. I had a Crown amp go bad and absolutley fried both drivers.

I got two new Martin Logan subwoofers from a dealer that was going out of business. The drivers were from MLs 8 foot tall sub stack. They where designed for 2cuft cabs as work great in these. On the back of each cab is a BASH 300 plate amp.

 

[djnagle]

Hi Andy, It will certainly help to flip them, but then raising then up off the floor will also help clean and tighten up the bass.

 

[Andyman]

Dennis, that's the plan for today. I can probably judge them pretty well that way w/o cutting the cabinet up and actually fitting the horn. I do need to open them up and secure the rock wool divider blanket so it doesn't flop out of the way and taint the results though. That and screwing down a couple cover plates in place of my acoustically challenged dirty laundry.

Then again, I may overlook the nuances of cotton vs. the detail of polyester...

 

[markw300d]

I've enjoyed this thread and find it a bit of an inspiration. I have been considering using my DLK2 cabs for Ewaves or Jeff Bagby's Fusion 12-Tempest design. The DLK2's are a decent speaker but after listening to Fortes and Quartets for quite a while, the DLK's just sit idle. "Smooth and easy to listen to has became "lifeless and boring". I need to either let them go or try something different.

Mark

 

[Andyman]

Well, I didn't get a chance to topsy-turvy the speakers, but actually did one better today. It turns out that the compression driver will fit through the mid cutout, so I wrapped my acoustically perfect laundry around the horn throats and was able to get them into the cabs.

Almost.

Looking at them over the weekend, it became obvious that the 2" or so lip would cause some sort of reflective chaos along the top lip of the horn, so I might have to have the horn either mounted proud of the motor board, or finesse some sort of curved horn flare extension molding for the top of the horn to ease the transition rather than crashing into a wall.

Pics below. Any ideas on the horn mounting??

FWIW, they do sound good; I've been playing them all weekend with the Altec SS amp and today switched to the Maggie 8802 6K6 tube amp. The tubes sound nicer to my ear, but I need to revisit some selections to make sure. I'm possible toying with bi-amping them using the tubes on the highs and the SS punch for the bottom.

Fun and games continue....

Frontal view

Side view showing cabinet lip and horn proud.

 

[madmonda]

Nice. I have pair of bozak's in the wings and sold a VERY nice pair some months back. The ones i sold have been tobanized; but im with you...they never really hit the spot for me. I couldnt get past the weak top end. But damn...they could shake the walls! I was at a toss up between ss and tube amplification myself. I was drooling over jbl's when i redid these (the pair i sold).

 

[Pio1980]

How does the coherecy at xover work out like that?
The rug on the floor in front will definitely help things if they are not elevated or tilted to get coherency.


Sent from my SM-N900V using Tapatalk

 

[djnagle]

You could make new baffles and bring them out flush. Leave the old one in place.

 

[Andyman]

Yep.

I'd like to keep the grill though, so I think I'll flush mount them and see how they sound.
The lip does bother me, but I may not even notice the reflections.

 

[lico]

Yeah, keep the grills - I think they will sound good.

 

[Andyman]

Yep.
I'll install them later today. I stuck a shim inthe horn last night and it looks like the sonic payh won't be as compromised as I expected and the highs should pretty much miss the lip.

Nice work on the LE14s;how do you like them? My first set used them in custom built cabinets and L liked them alot.