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JBL Speaker Project

Very nice, Duff. We're certainly "Leading Edge" on the HF; just need to clean up the bass a bit with damping, and reduce cabinet resonances with bracing. I have some ideas about how to do that from Mxlews's C36 project. Gotta still be able to remove the front baffle out the rear in those.... :yes:
 
Any bracing will need to have the ability to be removed later if needed. After I wrote my earlier post I decided to screw the stands to the cabinets. Maybe I'll do that before I visit. They are sounding pretty good listening to more Zep. I've been in a Zep mood getting ready for the concert tonight that only 18,000 people got to see and I wasn't one of them. :tears:
 
Shakedown:

Duff's got some cabinet leaks to seal up which lower his system "Q," and the bracing issue is yet to be resolved, but overall performance is per design (below). Orchid is 1/6 octave smoothed, black, unsmoothed. +/- 3 dB, 40 - 22 kHz, looks like. We didn't measure the bass nearfield, (tough with ported alignments,) but extension appears to reach 30 Hz nicely. (Next time....)

Tuning measured 28 Hz; we're going to bump that up to 30 Hz by shortening the ports a bit and tighten up the bass somewhat. We'll retest once that's complete and the cabs sealed and properly braced to lock in the final tuning.

Crossovers are working perfectly, with both mids and highs adjustable using this "quasi-three-way" (JBL 4430, Altec Model 19) topology. Both controls set to midpoint for this testing.

There were five of us here for the session. The consensus: "Wonderful!" Public debut at the Sac AK Fest, March 1.

Srbliss picked up his drivers and waveguides today, so we're moving on to a second iteration, this time using "as new" reconed JBL 2235H 15" woofers. He's doing the cabinets, and I'm tweaking essentially the same crossover for the project(s) to achieve smoother response.... :thmbsp:
 

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Duffs new toys

I was one of the 5 today. I must say the pictures don't do them justice. :thmbsp: The cabinets are very nice looking - more like good furniture than speaker cabinets.
Oh yeah they sound good too! Actually they sound very, very good. We only listened to one so no judgments about imaging and such can be made, but given the outrageous quality of the mids and highs I expect it to be very good indeed. The CD and waveguide makes CLEAN, crisp and clear sound that really must be heard in person to understand just how good it sounds, and they sound good off axis to boot. The first time I heard them (Zilches not Duffs) at the ZilchLab it kept me up almost all night thinking about how I could get that sound in my house.:music:
Steve.
 
srbliss said:
The first time I heard them (Zilches not Duffs) at the ZilchLab it kept me up almost all night thinking about how I could get that sound in my house.:music:
Steve.
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I swear, me too, I tossed and turned the night I heard them thinking should I spend the extra money for the JBL's or just use the BMS. :D I think I made the right decision. They are truly amazing.

Thanks for the nice words Steve and I look forward to seeing pictures of your JBLtecs when you get them together. :thmbsp:
 
Couldn't resist

Zilch said:
O.K., here's the checklist:
Open
Spacious
Detailed
Solid
Deep
Musical
Articulate
Tight
Defined
Accurate
Dynamic
Warm
Revealing
Realistic
Pounding
Powerful
Clear
Airy
Transparent
Smooth
Refined
Euphonic
Punchy
Romantic
Exciting
Natural
Trustworthy
Loyal
Brave
Clean
Reverent

:p:
​
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Well now..., that is a very nice list of mostly subjective impressions :deal:
 
They are finally finished!

Here are two pictures of the finished speakers. I made the tweaks Zilch suggested a few weeks ago and finished the grills today. I used a screen frame kit from Home Depot and the grill cloth from an old pair of speakers onepixel grabbed a while back. I purchased the vintage pair of original JBL badges a couple of months ago on eBay. onepixel, thanks again for the grill cloth! Zilch, thanks for all your help on this project! Now it's time to sit back and enjoy the music. :music:

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I can not imagine what it must be like to that knowledgeable and handy at the same time time. The system looks sooooo beautiful. Congratulations!

DK
 
Dark Knight said:
I can not imagine what it must be like to that knowledgeable and handy at the same time time. The system looks sooooo beautiful. Congratulations!

DK
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Thanks everyone. I didn't know anything before starting this project and learned quite a bit along the way. It was a fun project and the end result is a pair of speakers that sound pretty good to me. :thmbsp:
 
Duffinator said:
Thanks everyone. I didn't know anything before starting this project and learned quite a bit along the way. It was a fun project and the end result is a pair of speakers that sound pretty good to me. :thmbsp:
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Those speakers look SWEEEET!

I have not heard them, but I know they also sound the same.

Great job, Duffinator.
 
Duffinator said:
Here are two pictures of the finished speakers. I made the tweaks Zilch suggested a few weeks ago and finished the grills today. I used a screen frame kit from Home Depot and the grill cloth from an old pair of speakers onepixel grabbed a while back. I purchased the vintage pair of original JBL badges a couple of months ago on eBay. onepixel, thanks again for the grill cloth! Zilch, thanks for all your help on this project! Now it's time to sit back and enjoy the music. :music:

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Those really came out fantastic....

Excellent Job!:thmbsp:
 
gonzomeep said:
Great work there Duff. May I suggest a model name? ZD-2 Homage :music:
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Great idea. How about a small brass plate on the back of each speaker that says:

Speaker Design by: Duff & Zilch

California, USA 2008​

That would be cool. Snade
 
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