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Accidental 2-way: JBL 2226 + Altec 902/Martinelli Horn

tubino

tubino

A guy with too many tubes
What I did this weekend

I recently acquired a pair of new 2226 and used cabs from speakerman. The 2226 needed mechanical break-in, so I unloaded them straight into my garage loft/workshop. Hooked up the first SS recvr I stumbled over, a Pioneer SX-550. The bass was kinda obnoxious in the house (detached garage! 20+ feet away!), so I wired them out of phase and faced them at each other with ~8" between, standing on 2" thick fiberglass panels, and put the receiver on MONO. Really remarkable how well the cancellation works then!

But when I had work to do up there, I thought I should have TUNES!

Found two crossovers I made for a project, complete with Lpads and 10uF cap for the HF. Replaced the 2.7mH coil with a 1.2mH for the LF. I flipped the JBL cabs upside down, took some unused 902 drivers and Martinelli horns and hooked it all up.

469950737_QRU9x-L.jpg


Very promising! But I had to get those bass boxes working right, so cut two boards to fit over the rectangle where a horn had been mounted. To mark the holes, I threaded screws from behind until 2 threads showed, mashed board in place to mark screw holes, drilled both boards at once and mounted.

469951103_vuJQc-L.jpg


The 2226 are still breaking in, but even now I've got great workshop tunes! I thought these would go in the house, but they might have a life in my workshop!
 
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Interesting Rick!

I have a similar project waiting in the wings so it's good to hear how you are coming along with yours.


I like the Martinelli wood horns. Very classy.


When you say that you wired them out of phase, do you mean both out of phase or just one? Also, did you keep them wired that way after you sealed the old horn location?

The 2226's need to be connected out of phase more or less anyway I think unless using a 2nd order network:scratch2: I probably have that all bass ackwards though.



RC
 
doucanoe said:
Interesting Rick!

I have a similar project waiting in the wings so it's good to hear how you are coming along with yours.


I like the Martinelli wood horns. Very classy.


When you say that you wired them out of phase, do you mean both out of phase or just one? Also, did you keep them wired that way after you sealed the old horn location?

The 2226's need to be connected out of phase more or less anyway I think unless using a 2nd order network:scratch2: I probably have that all bass ackwards though.



RC
Click to expand...

I believe he was just talking about the break in....to do it silently, face the speakers towards each other, reverse the phase of one speaker,( the whole speaker, not an individual driver ), cover the whole mess with a blanket and let it break in. Cancellation will keep the noise down very well. You are right about the 2226H haveing the "black post causes forward movement" situation. As to the one speaker with reversed phase, You wouldnt want to listen this way. It just keeps the racket down while break in occurs.

Second order filters with 2-way typically require reverse phase hookups for the tweeter. The JBL (well, some of them ) woofers have the Black post causes forward movement thing alright, so the hot lead from the crossover will typically go to the Black post in these situations. This is so it will be "in phase"....boy, could I have made this any more confusing?

Russellc
 
Russellc said:
I believe he was just talking about the break in....to do it silently, face the speakers towards each other, reverse the phase of one speaker, cover the whole mess with a blanket and let it break in. Cancellation will keep the noise down very well. You are right about the 2226H haveing the "black post causes forward movement" situation.

Russellc
Click to expand...

I see that you are right now after re-reading. I need to pay closer attention the first time through I guess. I'm easily distracted by photos and shiny objects.

RC
 
tubino said:
What I did this weekend

I recently acquired a pair of new 2226 and used cabs from speakerman. The 2226 needed mechanical break-in, so I unloaded them straight into my garage loft/workshop. Hooked up the first SS recvr I stumbled over, a Pioneer SX-550. The bass was kinda obnoxious in the house (detached garage! 20+ feet away!), so I wired them out of phase and faced them at each other with ~8" between, standing on 2" thick fiberglass panels, and put the receiver on MONO. Really remarkable how well the cancellation works then!

But when I had work to do up there, I thought I should have TUNES!

Found two crossovers I made for a project, complete with Lpads and 10uF cap for the HF. Replaced the 2.7mH coil with a 1.2mH for the LF. I flipped the JBL cabs upside down, took some unused 902 drivers and Martinelli horns and hooked it all up.

469950737_QRU9x-L.jpg


Very promising! But I had to get those bass boxes working right, so cut two boards to fit over the rectangle where a horn had been mounted. To mark the holes, I threaded screws from behind until 2 threads showed, mashed board in place to mark screw holes, drilled both boards at once and mounted.

469951103_vuJQc-L.jpg


The 2226 are still breaking in, but even now I've got great workshop tunes! I thought these would go in the house, but they might have a life in my workshop!
Click to expand...


Really beautiful horns!:thmbsp: This project is very similar to what a few of us have done over on the econowave thread. That horn could probably use a little compensation to remove shout and flatten the response. Wayne posted a nice chart of values to use in the (incredibly huge) Econowave thread. One could also swipe the adjustible T-filter from the M 19 crossover.

Russellc
 
Russelc correctly deciphered my shorthand about wiring the two to cancel in order to reduce byproduct noise from break-in.

Russellc said:
Really beautiful horns!:thmbsp: This project is very similar to what a few of us have done over on the econowave thread. That horn could probably use a little compensation to remove shout and flatten the response. Wayne posted a nice chart of values to use in the (incredibly huge) Econowave thread. One could also swipe the adjustible T-filter from the M 19 crossover.
Click to expand...

Yes, the realization of how straightforward it can be to make a two-way system when you have a HF solution and the ability to make or adjust a crossover... that's the real lesson in the econowave thread, isn't it? I thought about posting there with a link to this thread, because of that shared approach.

Really, it's a matter of liberation through knowledge, eh? I didn't know where to start on this stuff, but speakerman guided me along till I'm starting to fell a lot freer about trying stuff and screwing up, as long as I don't break anything. So now I can try some stunt like this, and know it ain't optimal, but it's still pretty darn good till I make it better.

I don't know how to find stuff like that chart of values etc. in such a huge thread. Any help appreciated! I would like to know more about the M19 T-filter too.
 
I was looking around in the basement and found a couple of FOUR CHANNEL receivers. I guess if I didn't have an L-Pad I could use one channel per driver, and use the same post-amplification crossover parts. Kinda wasteful compared to using high- and low-pass BEFORE the amps, but hey... nobody's getting killed. But chances are I'll use some reworked tube amp in there when I replace the old Pioneer.

The view from low and center:

470078319_3NpDb-L.jpg
 
To those who commented on adding HF compensation to the crossover for the horn, Rick put these together as a quick "throw together" system. He will build a more refined crossover for the future utilizing Wayne Parham's new and improved Pi 2-way crosover when time permits.

Ron
 
Where are you crossing them? What type horn is that? CD, Tractrix???? I like the looks of those horns. How low do they go?
 
spkrman57 said:
To those who commented on adding HF compensation to the crossover for the horn, Rick put these together as a quick "throw together" system. He will build a more refined crossover for the future utilizing Wayne Parham's new and improved Pi 2-way crosover when time permits.
Click to expand...

True dat. I was looking to have some quick tunes while I continued to break in the woofers, and I was putting in additional flooring, and who wouldn't rather listen to music while working?

Dennis, I know very little about the horns. Those and the drivers were yet MORE items from Ron (!). I think they are tractrix, but not sure of cutoff frequency. I'm sure I'm well above it. 1.2mH is in the 1000 to 1200 area for the LF, and 10uf starts cutting down the HF considerably higher than that... but it's first order. I was kinda aiming for 1600, which would be more like 0.8mH LF, 12uF for HF. Next time I'm in the parts drawers I might look for a little lower value coil. EDIT These are 16 not 8 ohm drivers, so the 1.2mH isn't such a bad guess!

Hey, be sure to check out my more serious project thread on the BIG Jensen Imperials and HF horn.
 
The wooden horns in Rick's (tubino) system are Bill Martinelli's 630hz tractix horns.

Bill and I will probably disagree, but I would cross them over no less than 800hz.

Furthermore, I don't like to use 1" compression drivers under 1600hz, and 800hz for 1.4" and 2" drivers.

Just my 2 cents worth though!

Regards, Ron
 
I plugged in a CD player, so it's taking shape. As the drivers break in, it's sounding better and better! I copied spkrman57's layout for the new improved crossover, and that is saving me a lot of pointless dithering, so will have a better xover in there soon.

In the meantime I put in a 2.7mH coil for the 16 ohm 2226, and just as Ron guessed, the subjective effect was to increase apparent midrange by pulling down the UPPER midrange.
 
My interpetation of what you said....

tubino said:
In the meantime I put in a 2.7mH coil for the 16 ohm 2226, and just as Ron guessed, the subjective effect was to increase apparent midrange by pulling down the UPPER midrange.
Click to expand...

Adding addtional inductance to the LF crossover decreases the upper midrange the 2226 is reproducing which means less interference with the HF horn in the crossover region.

The crossover schematic I sent Rick will take care of all the little problems and I'm sure he will see a major improvemnt of the overall sound output of this neat little 2-way system.

Sorry to stomp on your post Rick!:D

Ron
 
spkrman57 said:
Sorry to stomp on your post Rick!:D
Click to expand...

No problem -- all comments welcome, but especially yours!
Thanks for the clarification.

Found the barrier strips a few minutes ago, so am about set to put the crossovers together. I had a nice pair of boards, just the right size... photos coming.
 
spkrman57 said:
To those who commented on adding HF compensation to the crossover for the horn, Rick put these together as a quick "throw together" system. He will build a more refined crossover for the future utilizing Wayne Parham's new and improved Pi 2-way crosover when time permits.
Click to expand...

And in fact, that's what I did. I made two of these, and hooked them up.

477575315_yPJrH-L.jpg


The L-pads are quality units I picked up with nice metal wall plates. I was able to screw them right into a block of wood, and voila, I have them solidly mounted and easy to adjust. You can sorta see it in this BEFORE photo.

476538999_CHygG-L.jpg


They work, too! Too cold to stay out in garage workshop for long, though.
 
Now with new bench and new crossovers!

It's a workshop, not a living room, and that's the way I WANT it. But I was happy to add the convenience of a bench I built a long time ago as a sort of test equipment stand for a test bench. Now it's in place as an equipment stand, with room for receiver, CD player, crossovers...

477741479_NDXet-L.jpg


Crossovers are hard at work now. Keeping the L-pad the way I got it, mounted to a very sturdy plate designed to mount in the wall. Works well for this application.

477735397_gKjLL-L.jpg
 
tubino said:
It's a workshop, not a living room, and that's the way I WANT it. But I was happy to add the convenience of a bench I built a long time ago as a sort of test equipment stand for a test bench. Now it's in place as an equipment stand, with room for receiver, CD player, crossovers...

477741479_NDXet-L.jpg


Crossovers are hard at work now. Keeping the L-pad the way I got it, mounted to a very sturdy plate designed to mount in the wall. Works well for this application.

477735397_gKjLL-L.jpg
Click to expand...


I love the use of the switch plate cover for the L-pad! Very crafty :thmbsp:

RC
 
Looks nice Rick!

Good orientation of the coils and excellent use of the little screw type barrier strips.

Now, how does it all sound and how many hours do you have on the new caps?

Doucanoe can appreciate the building of crossovers like you have just experienced!:yes:

Ron
 
spkrman57 said:
Good orientation of the coils and excellent use of the little screw type barrier strips.

Now, how does it all sound and how many hours do you have on the new caps?

Doucanoe can appreciate the building of crossovers like you have just experienced!:yes:

Ron
Click to expand...


Now Ron, I used two terminal strips per board also, and all you did was give me crap about using too many.

Actually, Rick does have a little more going on there than I did I guess :scratch2: :D

RC
 
Too funny Ron!

I knew I would get your attention.

By the way, Rick's crossovers started with some criticism from me also!!!

Ron
 
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