Zilch's AK Design Collaborative - Econowave Speaker

[Zilch]

So the standard LE-14 e-wave x-over worth a try with the B&C drivers?

Yes, but nobody has adjusted the HF comp for use with the high-efficiency highpass, which that crossover uses:

http://www.audiokarma.org/forums/attachment.php?attachmentid=151339&stc=1&d=1243017683

Measurements for DE250 on eWaveguide with throat adapter and "stock" high-efficiency highpass (probably) appear in this thread, back a ways....

 

[Russellc]

Those resistors were selected for the standard eWave highpass filter using 0.47 uF C3. Since the DE250 requires less HF comp than the Seleniums, it'll likely match LE14A nicely. I can try that to confirm. I should probably also run it with 2235H to determine why you're having to dial it back to 9:00....

eWave's about encouraging you to experiment. What's "established" here is merely by virtue of others having done exactly that.... :thmbsp:

It sure seems odd to me as well, but there it is. R1 and R2 are both 16 ohms, everything else is standard < 95 db E'wave crossover on the HP, L-pad at 9:00. LP is 4430, but the hot crossover lead goes to the black woofer post.........unlike the 4430.........:scratch2:
Anything less is like a lazer beam. I'll look everything over and make sure I havent screwed anything up when I changed out the resistors. As hot as it was, I was surprised that the 30 ohm series resistor dropped to 16, seems like it would allow it to play louder, but then I dont quite yet have measuring ability nor do I understand throughly how the other components interact, but it is hot for what ever reason.



russellc

 

[djnagle]

Those are beauties Rosso.

 

[Zilch]

It sure seems odd to me as well, but there it is.

What is C3?

 

[jackgiff]

What is C3?

That's the HF compensation capacitor.

 

[Russellc]

What is C3?

C3 = .47 uf. I have been dialing up the L-pad, and straight up and down noon is tolerable with anything
that isnt too aggressive sounding. A tendency to get a little crisp now and then on certain material.

russellc

 

[lico]

Yes, but nobody has adjusted the HF comp for use with the high-efficiency highpass, which that crossover uses:

http://www.audiokarma.org/forums/attachment.php?attachmentid=151339&stc=1&d=1243017683

Measurements for DE250 on eWaveguide with throat adapter and "stock" high-efficiency highpass (probably) appear in this thread, back a ways....

Was it this post? (post 4647) I always assumed it was the LE14A crossover being measured with the DE250.

http://www.audiokarma.org/forums/showpost.php?p=2549189&postcount=4647

 

[Zilch]

Was it this post? (post 4647) I always assumed it was the LE14A crossover being measured with the DE250.

http://www.audiokarma.org/forums/showpost.php?p=2549189&postcount=4647

Yes. See the hole at 2 kHz in comparison to the D220Ti, red? It's the throat adapter doing that, and raising the "Q" of the highpass may fix it, but I haven't gotten to trying that.

C3 = .47 uf. I have been dialing up the L-pad, and straight up and down noon is tolerable with anything that isn't too aggressive sounding. A tendency to get a little crisp now and then on certain material.

O.K., I'll check it. There's plenty of 2235Hs here; I just gotta develop a strategy to get one set up to measure.... :yes:

 

[dushuai]

I'll see how the testing of that little one goes...think I may have a project for it. I noticed another thread where a bunch of guys are doing a group buy on the Pyle version of econowaveguide. Dont know if they're getting a discount or if they are just all ordering together as they have an event to go to and its just handy?

We'd probably need more than 2 to get any advantage, and I dont know if JBL pro would offer any discount. These horns are awfully inexpensive, may not be worth a group buy? We'll see how it goes.

If all those guys build econowave, ( which I suppose they are or wouldnt be buying the waveguides)

Russellc

I see the test is helpful ,even though the devices are cheap,but it worth at all,

 

[jackgiff]

Footed Cabinets

I bought a two by four this morning and cut some feet for the Trapezoid cabinets. This will solve a couple problems. 1) It will raise them close to three Inches, and 2) It will tilt them back a few degrees so the HF waveguide is aimed up to the listener.

Oh, and 3) it will allow the tuning port to exit the bottom of the cabinet. WinISD says to tune the cabinet to 24.5 HZ for the DC300-8 will take a three inch port about sixteen inches long. This will allow porting it with no elbows in the port.

The DE250's arrived this morning, and the DC 300's are due next Tuesday. The front panel will be finished by tomorrow, so everything will be a GO next week.

 

[skywave-rider]

Sweet

I am stealing that.
Seriously.
I was gonna put the same tilt on mine by copying the Heresy riser, but I'm gonna lift your design instead. :thmbsp:

 

[Zilch]

Interestingly, DC300 frequency response doesn't vary much in 1.7 cuft tuned anywhere between 25 and 35 Hz, here shown in 2.5 Hz increments:

The power handling certainly does, though:

I'd tune to 30 Hz (blue), which is a 3" port 10.25" long, or a pair of 2" at 9.375".

In the stock 1.6 cuft., which behaves similarly, the lengths are 11.09" and 10.14", respectively. :yes:

[Heavy fill confers no advantage.... ]

360144/7071=50.9325​

 

[Zilch]

Preliminary mods for DE250 on QSC waveguide using the eWave high-efficiency highpass were posted ~10 pages back:

Component values in the legend.... :thmbsp:

 

[jackgiff]

I am stealing that.
Seriously.
I was gonna put the same tilt on mine by copying the Heresy riser, but I'm gonna lift your design instead. :thmbsp:

Great, that is why I posted them. straight feet will do the job and be easier to cut. Most of the cuts were done on the table saw, but I don't have an attachment to allow me to use the fence and get the long angle cuts, so I had to do that on the radial arm saw. If you figure an easier way, please post it.

Interestingly, DC300 frequency response doesn't vary much in 1.7 cuft tuned anywhere between 25 and 35 Hz, here shown in 2.5 Hz increments:


The power handling certainly does, though:



I'd tune to 30 Hz (blue), which is a 3" port 10.25" long, or a pair of 2" at 9.375".

In the stock 1.6 cuft., which behaves similarly, the lengths are 11.09" and 10.14", respectively. :yes:

[Heavy fill confers no advantage.... ]

360144/7071=50.9325​

Wow, that BB6P program is neat. All I have is WinISD. It won't figure the power handling (at least I don't know how to do it). When I plotted the DC 300-8, it was apparent that the -3 dB point was pretty much the same, so I opted to go with what WinISD recommended.

I am assuming that the highest power tuning is the one with the least bass extension, and that it is the 37 Hz plot. It seems that the power handling would be nice to have. Why then do you recommend 30 Hz over the 37 Hz? I will go with 30 gladly, but curiosity impels me to ask. Is the power handling at 30 Hz adequate for our application?

Maybe BB6P will be my next program.

 

[skywave-rider]

Zilch,
I got semi-similar results for DC 300. But look at it closed box in 1.72 cu. Looks great. I assume there is a reason you don't like it. Is it power handling? I thought Gordon had previously suggested it in closed box.

Red: DC300-8 sealed
Blue: DC300-8 ported (tuned to 30 Hz w/ one 3" port at 9")
Green: Eminence Delta 12 LFA (tuned to 45 Hz w/ two 3" ports at 8.3")
Yellow: JBL 123A sealed

 

[Russellc]

Zilch,
I got semi-similar results for DC 300. But look at it closed box in 1.72 cu. Looks great. I assume there is a reason you don't like it. Is it power handling? I thought Gordon had previously suggested it in closed box.

Red: DC300-8 sealed
Blue: DC300-8 ported (tuned to 30 Hz w/ one 3" port at 9")
Green: Eminence Delta 12 LFA (tuned to 45 Hz w/ two 3" ports at 8.3")
Yellow: JBL 123A sealed

How did you post this? ( response chart ) I tried to send it to a file, it seemed to upload,
but never appeared on the post..:sigh:

Russellc

 

[skywave-rider]

Did u select the attachment icon in the post composition window? After selecting it, you get an upload window. Has to be a compatible file. There's a list of compatibles in the upload window. I assume you did that though and it was a server problem.

 

[Zilch]

I am assuming that the highest power tuning is the one with the least bass extension, and that it is the 37 Hz plot. It seems that the power handling would be nice to have. Why then do you recommend 30 Hz over the 37 Hz? I will go with 30 gladly, but curiosity impels me to ask. Is the power handling at 30 Hz adequate for our application?

They all have basically the same extension in the range of interest, so the determination shifts to power handling capacity. We have 104 dB at 80 Watts, so 101 dB at 40 Watts. Tuned to 30 Hz, it'll play that level at a lower frequency before falling precipitously. Tuned at 25 Hz, we're limited to 3 dB lower.

Cursor's at -6 dB, the effective lower limit of usable bass on the frequency curves, ~37 Hz, so there's no advantage to tuning low and compromising the power handling at the very bottom. Pick yer poison; all of these tunings will sound about the same, according to the model.... :yes:

 

[jackgiff]

They all have basically the same extension in the range of interest, so the determination shifts to power handling capacity. We have 104 dB at 80 Watts, so 101 dB at 40 Watts. Tuned to 30 Hz, it'll play that level at a lower frequency before falling precipitously. Tuned at 25 Hz, we're limited to 3 dB lower.

Cursor's at -6 dB, the effective lower limit of usable bass on the frequency curves, ~37 Hz, so there's no advantage to tuning low and compromising the power handling at the very bottom. Pick yer poison; all of these tunings will sound about the same, according to the model.... :yes:

OK, that makes sense. It will be tuned to 30 HZ then, and of course can be played closed box by application of a ZilchPlug.

 

[Zilch]

Zilch,
I got semi-similar results for DC 300. But look at it closed box in 1.72 cu. Looks great. I assume there is a reason you don't like it. Is it power handling? I thought Gordon had previously suggested it in closed box.

BB6P says it'll only handle 5.25 Watts at 37 Hz closed box. Easy enough to find out by closing the ports using ZilchPlugz™.

OK, that makes sense. It will be tuned to 30 HZ then, and of course can be played closed box by application of a ZilchPlug.

Great minds....