Zilch's AK Design Collaborative - Econowave Speaker
- Thread starter Zilch
- Start date
When you framed these, did you cut the hole for the horn from a piece of plywood, or just frame it all around with those 1 x1 (sticks)?
Nicely done. I have a set I haven't mounted up yet.
This is my first try at cabinet making. The 1/4" birch plywood chipped the first layer when using the power saw. Finally got it cut with a utility knife and the miter saw. The bevel had to be done with a surform file. Looks like a cheese grater in a plane body. The next cabinet will be thicker material so I can use power tools. These are more like 1950's light weight furniture than true speaker boxes.
It's all good and it looks great. I use a jigsaw blade that has the teeth facing down. No rip-out on the face side. Yeah, I get it, turn it over, but it works for a lot of other woodworking tasks. I like the 1/4 wood idea. Easy to work with and no resonance to worry about really.
Will exercise give those woofs a lower F in cab?
One can hope. I have them playing a test tone at the box tuning(35HZ) now. I will pm GordonW to see how long the break in should take. These are technically mid woofers. An E-120 frame and 2204 cones with an added mass ring. Friday I should have the house to myself. That will let me do some sweeps at a higher volume.
How are they sounding to you right now?
Are you measuring the changes? Not that they're everything, depending on the person, but they can get you closer.
The jbl woofers drop off at 100hz period. Sealed the ports same result. One port only same result. Tuned ports to the recommended tuning from the 2204 spec sheet. Lost a little below 45hz. I will try adding fiberglass insulation and test again.
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300Z
Leo
How's this being measured?
Dayton mic using spectroid on my phone.
Fs is 60 for the E120. Fs for the 2204 is 45. Suggested tuning for the 2204 is 50 hz. The frame is an e120 and cone is a 2204. Gordon added a mass ring from the parts he had. Other than the lack of bass below 100 hz these image well and sound nice. They may just need a sub.
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Since you mounted those JBL's to the back of the baffle board ( while JBLs are historically front mounted ), I'd suggest closely examining the existing cut-out to make sure 100% of the woofer's surround is free & clearly visible ( and not obstructed by any wood over-hang else you might be restricting the woofers compliance > effectively raising the woofers' Fs, mechanically ).
That's about all I can think of that would give you such unexpected results ( when using OEM JBL parts ).
If they were mine I'd be yanking a woofer and measuring it's Ts parameters ( mostly wanting to know the Fs ).
It's a shame you can't do that.
PS: Also, the E120 magnet is slightly larger//stronger resulting in a couple of db increase in the midrange output ( not that this explains the dramatic drop-off seen below 100hz, since magnetic strength doesn't dictate Fs ).
For that to happen I suspect your woofers Fs must be quite a bit higher than expected from OEM kits ( or your box tuning just isn't what you think it is ).
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This is the box tuning website I am using. http://www.mobileinformationlabs.com/HowTo-1Woofer-Box-CAL Port lenth 1.htm 3.8cubic feet , 2 ports ,52hz and the result is .75 inch. This is the baffle thickness. I will mount the woofers on the front and report back.
Forgive me if I don't remember, do you have T/S parameters for this driver? (2206)
