Zilch's AK Design Collaborative - Econowave Speaker

[fastbike]

Detail question on driver mounting

Folks, I was trying to follow some of the discussion on relative mounting depth between the waveguide and the woofer (JackGriff, I believe) and I couldn't find the end of the discussion.

I'm using the PH-612/220TI/DC300 combo.Here's the question.

Should I flush mount the wave guide and the woofer? Flush mount the woofer, surface mount the wave guide? Something else? Does it matter that much? Cabs are Realistic Mach One (4024a) ~ 2.4 cu ft.

Thanks
Larry

 

[Zilch]

Flush or surface mount, it doesn't matter all that much. The issue arises primarily as a consequence of the QSC being 1.25" deeper than the standard eWaveguide, and we have not yet entirely resolved how to deal with that....

 

[doucanoe]

Flush or surface mount, it doesn't matter all that much. The issue arises primarily as a consequence of the QSC being 1.25" deeper than the standard eWaveguide, and we have not yet entirely resolved how to deal with that....

If you are talking about time alignment, a separate enclosure or "baffle head" in my case solved that for me. I put some thought into this

RC

 

[Vaughn]

Electrovoice SP12C econowave anyone?

 

[Zilch]

Electrovoice SP12C econowave anyone?

I saw that, but just don't know; I'm hoping somebody does.

If not, try it and see. I'm going for more JBL drivers next: 2214H, 125A, 127H-1, 128H, LE111A, others.... :thmbsp:

 

[Vaughn]

Yeah, I think it would be fine...

It does require a 5.5 cu ft box to do 40hz and I think would be best suited to
the high efficiency version of the Ewave crossover. I think it certainly goes high enough to mate well with the waveguide. I am listening to a pair right now run full range and they sound pretty good, but I'm sure would take a huge step with the Ewave treatment.

Of course I could use them in a smaller box and use a sub...

 

[ArtD]

I'm going for more JBL drivers next: 2214H, 125A, 127H-1, 128H, LE111A, others....

In this thread I've seen L26 cabinets used for eWaves but not the actual 125A drivers. I'll be interested to see what you do as I've promised my daughter that I'll build her eWave Barzilay look-a-likes using 125A bass drivers and, once made, those type of promises have to be fulfilled.

I do have a copy of a pre-eWave thread in the LH forum where you were using the 125A driver in sealed enclosures though, which leads to the following question. From your knowledge of that driver what would you think is the ideal volume for a closed box speaker using the 125A driver?

I like the quality of bass that I've heard from sealed enclosures over the years and would like to go that route with eWaves.

 

[Zilch]

In this thread I've seen L26 cabinets used for eWaves but not the actual 125A drivers. I'll be interested to see what you do as I've promised my daughter that I'll build her eWave Barzilay look-a-likes using 125A bass drivers and, once made, those type of promises have to be fulfilled.

http://www.audiokarma.org/forums/showthread.php?p=2132952#post2132952

That's 127A/H in KLH-6, same driver with inverted dust cap. BB6P says they'll play down to 42.73 Hz at -6 dB, closed box, 100 dB max. If you want to rock the house 6 dB louder down there, port them like L26.

 

[ArtD]

Thank you for that. I see that the KLH cabinet has even less volume than the L26, it seems these closed box speakers can be quite small.

 

[4343]

Hey, I have some of those!

I saw that, but just don't know; I'm hoping somebody does.

If not, try it and see. I'm going for more JBL drivers next: 2214H, 125A, 127H-1, 128H, LE111A, others.... :thmbsp:

Ooh! LE111A, 128H! Although my L110's and L112's would never forgive me if they got gutted for a DIY cab, would they?

I was thinking of cutting my baffles for 12" and then making an offset ring to put a 10" in, have to try that with my circle jig tomorrow. (Offset ring means cutting the 10" opening offset to the 12", so the edge of the 10 will be as close as possible to the waveguide.)

 

[Zilch]

QSC446 & D220Ti Bolt-on

HF response is +/- 2 dB out to 18 kHz. Crossover's in the "right" place. Don't know if the 6 dB dip at crossover is because the lowpass needs more tweaking with LE14A using this waveguide, or it's the vertical nulls impinging upon the pattern with this wide (12.5") center/center distance.

With the waveguide flange 2" forward of the woofer and the drivers playing in phase, the forward axis is 3" below waveguide center at 42" mic distance.

From the perspective of the high-frequency performance, then, this combination, which is in full conformance with the original eWave economic model, is good to go; just remember to invert the HF driver polarity.

What I'm hearing sounds quite nice, as well.... :thmbsp:

 

[Zilch]

I was thinking of cutting my baffles for 12" and then making an offset ring to put a 10" in, have to try that with my circle jig tomorrow. (Offset ring means cutting the 10" opening offset to the 12", so the edge of the 10 will be as close as possible to the waveguide.)

I'm betting that's gonna work just fine.... :yes:

 

[Russellc]

From the perspective of the high-frequency performance, then, this combination, which is in full conformance with the original eWave economic model, is good to go; just remember to invert the HF driver polarity.

Would that remove the dip at crossover frequency?
Russellc

 

[ROSSO]

...From the perspective of the high-frequency performance, then, this combination, which is in full conformance with the original eWave economic model, is good to go; just remember to invert the HF driver polarity.

What I'm hearing sounds quite nice, as well.... :thmbsp:

Would that remove the dip at crossover frequency?
Russellc

Noting that the woofer here is a reverse polarity JBL LE-14A, "+" to BLACK, if we invert the HF then we will have BOTH "+" leads from the PCB Xover attached to the BLACK terminals on these drivers? Could we achieve the same result with less future confusion by doing the more conventional RED to "+"?

 

[dnewma04]

Vaughn,

SP12C should work very well.

 

[Bauhausler]

HF response is +/- 2 dB out to 18 kHz. Crossover's in the "right" place. Don't know if the 6 dB dip at crossover is because the lowpass needs more tweaking with LE14A using this waveguide, or it's the vertical nulls impinging upon the pattern with this wide (12.5") center/center distance.

With the waveguide flange 2" forward of the woofer and the drivers playing in phase, the forward axis is 3" below waveguide center at 42" mic distance.

From the perspective of the high-frequency performance, then, this combination, which is in full conformance with the original eWave economic model, is good to go; just remember to invert the HF driver polarity.

What I'm hearing sounds quite nice, as well.... :thmbsp:

That's the bolt-on version of the D220Ti, right, and not a thread-on with an adapter?

*** EDIT ***

and the Ewave crossover?

 

[Zilch]

Would that remove the dip at crossover frequency?
Russellc

That, sir, is the question. I'll do this again with the waveguide and woofer mounted in the trap cab and get closer to the answer. It's just not real productive doing a bunch of tweaking of this combo under these conditions, as we learned with DE250. The fundamental compatibility is clear; eWave HF comp plays bolt-on Selenium D220Ti well on the QSC waveguide. As with DE250, however, some optimization may be required.

Noting that the woofer here is a reverse polarity JBL LE-14A, "+" to BLACK, if we invert the HF then we will have BOTH "+" leads from the PCB Xover attached to the BLACK terminals on these drivers? Could we achieve the same result with less future confusion by doing the more conventional RED to "+"?

Yes, but we decided early on that the best approach when using inverse polarity JBL drivers is to "correct" that so that they will play with other industry standard systems as, for example, in a HT setup.

That's the bolt-on version of the D220Ti, right, and not a thread-on with an adapter?

And the Ewave crossover?

Yes, in this instance, the LE14 crossover variant, as that's the woofer I'm using.

I had forgotten how much I like LE14s, as the one in the test stand has been connected as a sub for the last several months....

 

[Vaughn]

Vaughn,

SP12C should work very well.

Hey, Gracias!

They seem like very well built drivers that don't command much money, so not much point in selling them!

Now if I can just come across some decent looking 5.5 cu ft cabinets I will be one large step closer to completion.

 

[djnagle]

Hey, Gracias!

They seem like very well built drivers that don't command much money, so not much point in selling them!

Now if I can just come across some decent looking 5.5 cu ft cabinets I will be one large step closer to completion.

The best midbass I've ever heard was from a pair of EV Patrician 700s I had a couple years back. The SP12 was in a 18x36x12 boxed off section. The baffle board was only half the front...just enough to hold the SP12. The box was lined with yellow batten. Man, those things hit like a bullet. I'd try that and maybe expect to need a sub.

 

[dnewma04]

While I'm an advocate of subs with nearly everything, the SP12Cs will go deep enough that I think some people would be pleasantly surprised by them. I have two pairs of them in my big EVs and I'm thinking they might make a fine looking MTM ewave at some point in the future.