Zilch's AK Design Collaborative - Econowave Speaker

[Zilch]

Yeah, the legs thing is fun stuff. It's the Salamander Stilettos on mine, the black ones.

Ports will tune the cabs according to the internal volume and woofer used. We found room for a pair on the front baffle of Wiredbecker's C36s using LE14A and the standard eWaveguide. There's a pic in this thread showing their location. My own pair are closed boxes with JBL 2213H woofers.... :yes:

 

[Tube King]

Yeah, the legs thing is fun stuff. It's the Salamander Stilettos on mine, the black ones.

I think I'll include the wife in on this. It will help ease her into our new furniture if she has more of a part of it. She already promised to "stain" them and picked the color so I think things are going well.

Ports will tune the cabs according to the internal volume and woofer used. We found room for a pair on the front baffle of Wiredbecker's C36s using LE14A and the standard eWaveguide. There's a pic in this thread showing their location. My own pair are closed boxes with JBL 2213H woofers.... :yes:

Dayton DC300-8

I didn't find wiredbecker's post with that however I did find the one where he is stacking the waveguide on the top of the C36 cab instead of inside.
http://www.audiokarma.org/forums/showpost.php?p=2090293&postcount=900

 

[skywave-rider]

Oooh!

impulse shows the woofer delayed ~0.1 ms, red, equivalent to 1.39" rearward offset:

the forward vertical patten tilted downward ~3.9°

[it also messed with the lowpass filter some.... ]

 

[donprice]

premium eWave?

4555 is the 1.5" BMS that bolts up to the full array of JBL PT waveguides, which are ~$100 each, the "Premium" combo Jack mentioned above.... :yes:

What is the design objective for the "premium" combo (pWave?)? Lower cross-over frequency sort of like the JBL 4430?

You guys are killing me. I'm still waiting on backordered parts to complete my second eWave pair and I'm already thinking about how to modify the layout of the baffle to make the pWave upgrade easier.:scratch2:

 

[Russellc]

What is the design objective for the "premium" combo (pWave?)? Lower cross-over frequency sort of like the JBL 4430?

You guys are killing me. I'm still waiting on backordered parts to complete my second eWave pair and I'm already thinking about how to modify the layout of the baffle to make the pWave upgrade easier.:scratch2:

Yes, the first sign is denial, then anger, and finally acceptance that you are hopelessly stuck in the E'wave groove. Its not so bad!:tresbon:

russellc

 

[juniorJBL]

Yes, the first sign is denial, then anger, and finally acceptance that you are hopelessly stuck in the E'wave groove. Its not so bad!:tresbon:

russellc

Awww. you just had to go and tell him that he is doomed didnt you!!

 

[Bauhausler]

I got an email today saying the QSC waveguides have been shipped. Now is the time to order if you want to try these out.

Denny

Ditto. FedEx. I hope to have them in hand early next week.

 

[jackgiff]

Impulse shows the woofer delayed ~0.1 ms, Red, equivalent to 1.39" rearward offset:

The forward vertical patten tilted downward ~3.9°

[It also messed with the lowpass filter some.... ]

Which of the two circuits Brandon supplied was used for this test? And how did it effect the low pass filter?

 

[Zilch]

What is the design objective for the "premium" combo (pWave?)? Lower cross-over frequency sort of like the JBL 4430?

Yeah, like that, taking us back to the roots. Perhaps we can recruit David Smith to join the band:

eWave "Standard"
dWave "Deluxe"
pWave "Premium"
uWave "Ultimate"

Which of the two circuits Brandon supplied was used for this test? And how did it effect the low pass filter?

Still set up, I'll get a pic and some data posted later today.... :yes:

 

[Bauhausler]

Yeah, like that, taking us back to the roots. Perhaps we can recruit David Smith to join the band:

eWave "Standard"
dWave "Deluxe"
pWave "Premium"
uWave "Ultimate"

For Gordon's monsters I propose the title Draupner Wave.

 

[GordonW]

For Gordon's monsters I propose the title Draupner Wave.

(to the tune of U2) "All is quiet... until New Year's Wave..."



Regards,
Gordon.

 

[freddyi]

got any suggestions of waveguide and xover to go with my B&C 15TRX40 woofers? I once mocked up the 12" Dayton waveguide and that might work if xover not too low

 

[tbbenton]

Ditto. FedEx.

I have a pair in my hands now in Portland, OR, and they are frighteningly large (10"x14"). Did I order the wrong ones (PL-000446-GP)?

BTW, they overnighted them to me. I asked for the old price. They wouldn't give me the old price, but they upgraded my shipping. Nice guys!

 

[jackgiff]

I have a pair in my hands now in Portland, OR, and they are frighteningly large (10"x14"). Did I order the wrong ones (PL-000446-GP)?

They really are BIG!! :jawdrop:

 

[Russellc]

I have a pair in my hands now in Portland, OR, and they are frighteningly large (10"x14"). Did I order the wrong ones (PL-000446-GP)?

BTW, they overnighted them to me. I asked for the old price. They wouldn't give me the old price, but they upgraded my shipping. Nice guys!

That's it. Not that big, at least when compared to 511B! ( As well as tons of other giant Altec horns)

Russellc

 

[Zilch]

Which of the two circuits Brandon supplied was used for this test? And how did it effect the low pass filter?

It was three, I believe, and following his pattern, I progressively adjusted the cap values downward, ending up at 0.5 mH, 6.2 uF, which got me close enough to make comparative maps of the forward patterns with vs. without, and pos vs. neg polarity HF:

With each iteration, I checked the impulse response, and the delay did not appear to change with different cap values; I was mostly trying to obtain a measureable system response. Here's the difference in woofer response with and without the ladder network:

I should put it in Spice and see what's going on, but frankly, I'm not convinced we need any additional delay at this point, much as you found.

BTW, there's a related discussion going on over on the PE Tech Talk forum:

I agree, the lack of time alignment seems to plague most DIY speakers and most commercial speakers.

This is not true. In MOst cases, physical time aligment has nothing to do with a speaker's performance in the time domain. With analog crossovers, time alignment of drivers is required only by a transient-perfect system with acoustic 1st order filters. It is useful for acoustic 2nd order filers, too, but it is mainly to obtain good on-axis phase tracking (and thus flat summation of drivers), not to improve the finished system's performance in time domain---the sytem's total phase wrap is 180 degrees, anyway. The most popular, easy-to-use crossover type is the Linkwitz-Riley acoustic 4th order filter, which must be employed by over 90% of commercial and DIY speaker designs with drivers mounted on a flat baffle (w/ 5.25" or larger midrange and no-wave-guided dome tweeter). In this case, we typically use what we call asymmetric filter to obtain drivers' good phase tracking. If it is implemented correctly, it exhibits virtually no difference in terms of the system's phase behavior from a time-aligned LR 4th order system.

And in the case of LR4, an asymmetric crossover with drivers on a flat baffle generally takes less components than time-aligned LR4 because we can obtain a relaxed rolloff on the woofer by using only a 2nd order electrical filter.

Read on from there:

http://techtalk.parts-express.com/showthread.php?p=1604864#post1604864

 

[Robh3606]

Hello Zilch

Did you try to look at the Step Response of the System with and without the Delays in place?? When I was doing averages over my listening window looking at a 3 way I could easilly see the time offsets in the Step Response between the Horn and Mid as I changed height. Might be easier to see that way.

Rob

 

[juniorJBL]

Hi Rob!! How have you been? Thanks for your input here.

 

[Zilch]

Did you try to look at the Step Response of the System with and without the Delays in place?? When I was doing averages over my listening window looking at a 3 way I could easilly see the time offsets in the Step Response between the Horn and Mid as I changed height. Might be easier to see that way.

Hi, Rob!

Yup, but I never thought of comparing with the ladder delay. I'll try that to confirm the findings from the impulse. I can certainly see the relative shift of HF vs. LF in the impulse as I move up and down. I suppose that info could be used to correlate the relative offset of acoustic centers we're dealing with here derived via different approaches.

I'm about to punt and let LEAP do this; I'm not even sure I've found the forward axis yet.... :tongue:

470041/8557=54.9306​

 

[donprice]

got any suggestions of waveguide and xover to go with my B&C 15TRX40 woofers? I once mocked up the 12" Dayton waveguide and that might work if xover not too low

You can always start with the start with the standard crossover for high-efficiency (>95 dB) woofers and experiment with the low-pass section (L2 & C2) based on how it sounds. That's what I'm preparing to do with the Eminence Kappalite 3015...which has a response curve that looks a good bit like the 15TRX40 with some weirdness 1000-2000 Hz. First attempt will be using the standard low-pass at 1200 Hz and the second will be using the 900 Hz low-pass variant worked up for the JBL LE14. I don't have a testing rig so I'm hoping one is a clear winner that requires no further tweaking.

I'll be going with the "standard" Pyle clone of the 6 x 12 JBL waveguide. At $12 each it is hard not to give them a try. Someone here has probably tried the 12" Dayton's...search the thread for the part number.

You have no doubt caught the recent discussions of other waveguides and drivers. Perhaps someone will recommend a combination to try. The general opinion is that the standard eWave is hard to beat and a real bargain.