Flex Your PCD Mettle:

[dantheman]

Here's a little more info on the decay d/t diffraction effects:





Looks like Dr. Geddes is right however, these things don't show us anything that the impulse and polar response didn't. None the less, Daddy likes the new tools.

Oh, sorry for all the additional reflection in the cottoned response. You can see in the impulse that mic placement wasn't as good.

Dan

[Zilch]

Un-normalized CSD of Behringer, no?

[I may have to buy a pair to use as "standard" here....

[dantheman]

Yea, they graphs aren't normalized. Cool little speaker. Don't expect them to get up and go like those PA jobbies you've been messin with, but they'll get the job done.

Dan

[Zilch]

Use Jantzen or Solen 10uf for C1 if building on eWave PC boards.

[Greg01]

I know that you stated earlier in the thread that Dayton woofer does not have a commanding low end. I was just wondering how this system compares to the Econowave Deluxe.

[Zilch]

The 7 Hz lower Fs of the Eminence 3012LF in Deluxe allows it to reach audibly deeper. Using the same assist, PA310 still needs a sub with this box size and tuning.

From the curves, it's apparent that there's more LF extension to be coaxed out of PA310 in SR, but are we willing to give up efficiency to get at it? Someone's going to have to do a more comprehensive analysis of this woofer to ascertain the optimum alignment and compensation.

We'll have another shot at it next in SRC (compact).

[C'mon box modelers, show us your chops...! ]

[Pete Schumacher ®]

The 7 Hz lower Fs of the Eminence 3012LF in Deluxe allows it to reach audibly deeper. Using the same assist, PA310 still needs a sub with this box size and tuning.

From the curves, it's apparent that there's more LF extension to be coaxed out of PA310 in SR, but are we willing to give up efficiency to get at it? Someone's going to have to do a more comprehensive analysis of this woofer to ascertain the optimum alignment and compensation.

We'll have another shot at it next in SRC (compact).

[C'mon box modelers, show us your chops...! ]

Do you have the actual measured TS parameters?

Using what they have on the product page, I have 2 cubic feet tuned to 55Hz giving F3 at 52Hz.

You just ain't gonna get any serious bass from this, no matter what. A sub is required for some music.

[Zilch]

Thank you, Pete.

I have not measured the T/S parameters.

Your model is consistent with what I'm hearing....

[carrera]

Use Jantzen or Solen 10uf for C1 if building on eWave PC boards.

Hi Zilch, newbie here to this board but not to your threads where I am becoming a curve junkie myself. Love your charts, wish I had the equipment. Any chance you and Pete S. have tried this setup with a Kappalite 3015LF or any interest for that matter? Thanks.

[robert]

Zilch/Pete: got to hear and measure Ed's Econowaves this weekend and they are a sweet and simple design. BTW my measurements were VERY close to the model for Deltalite II / B+C so some more independent backup for measurement/modelling. it was a kick seeing app. 6" of acoustic delay from the front baffle to the compression driver.

This is a fun to listen to, LOUD, and very nice looking design with a cool retro look. Couple questions:

1.) I measured SPL on tweeter axis and wanted to know if the slight downtilt of on-axis SPL of the HF horn was part of the design; and/or did you consider a parallel RC circuit on the compression driver XO to smooth out 2-4Khz a bit and remove all or some of the downtilt? I am very new to how horns work, so you can consider this a "noob" question.

Cheers / Robert

[Zilch]

Hi Zilch, newbie here to this board but not to your threads where I am becoming a curve junkie myself. Love your charts, wish I had the equipment. Any chance you and Pete S. have tried this setup with a Kappalite 3015LF or any interest for that matter? Thanks.

There's some discussion of using 15s in this and other threads, and plenty of eWaves have been built by others using them. There are issues which must be addressed, primary among these being the necessarily increased center-to-center distance between woofer and waveguide and it's impact upon crossover frequency and height of the forward vertical lobe, also directivity matching and the pattern control limitations of available waveguides.

I don't mean to suggest that these are insurmountable, and Wayne Parham has shown via actual product that successful design(s) using 15" woofers are achievable; it's more that my own resources are dedicated to working with smaller drivers, and as you see, that plate is heapingly full.

I measured SPL on tweeter axis and wanted to know if the slight downtilt of on-axis SPL of the HF horn was part of the design; and/or did you consider a parallel RC circuit on the compression driver XO to smooth out 2-4Khz a bit and remove all or some of the downtilt?

Yes. As I have shown in at least one of the designs here, it's easy to tilt the HF region. Measured anechoically (or quasi-), flat response gets tilted down by the room's reflective interference, absorption, and distance, which is easily seen in in-room response measurements. Still, with constant directivity extending through the top octave, there is considerably more energy being broadcast up there, and the power response is flatter. At some point, the perceived balance becomes overly bright even without the on-axis response being upwardly tilted, and compromise is in order.

I hope, again, everyone is getting that we are demonstrating a process for developing these designs as well as an array of examples which may be replicated. The intent is for others to more fully explore these concepts as varying resources and desire may warrant. EconoWave's success is largely attributable to the degrees of freedom it affords all participants; Ed's design belongs to Ed, and it is apparently well-appreciated by others, including myself and Pete too, no doubt. There are plenty of DIY pleasures to be discovered and practiced here....

[fastbike1]

I've tried from 1.5 to 2.5 ft3, sealed and ported. I can get to F3 high 30's ported but am way over xmax @30 watts (~104dB). I agree that the PA310 just isn't going to play low.

You just ain't gonna get any serious bass from this, no matter what. A sub is required for some music.

[Mayhem13]

Hey Zilch, these look like a serious E-wave contender!

http://www.parts-express.com/pe/psho...95&ctab=2#Tabs

The FR looks suprisingly good to 1.8 or so. The Fs is pretty low at 48hz as well and xmax is on par with the kappalight 12-HO. I'll do some bass alignment sims to see how things look.

[Pete Schumacher ®]

Hey Zilch, these look like a serious E-wave contender!

http://www.parts-express.com/pe/psho...95&ctab=2#Tabs

The FR looks suprisingly good to 1.8 or so. The Fs is pretty low at 48hz as well and xmax is on par with the kappalight 12-HO. I'll do some bass alignment sims to see how things look.

The Qts is very low, which means again, very little bass extension.

[Mayhem13]

Not too shabby really......if used with a sub which is a given for HT use.

[Pete Schumacher ®]

Not too shabby really......if used with a sub which is a given for HT use.

After you factor in baffle step, yeah, it's still pretty anemic. Better would be to make that response flatter, with a higher tuning frequency.

If you are using a sub, may as well get the low end sensitivity up at least even with the mid band, maybe even forget going vented altogether.

[edlafontaine]

Mayhem,

I'm with Pete on this. Your sim has a 6 dB difference between the 50-80 Hz range and 500Hz. The response of the mid-woofer should be "flat" down to the point where you would get usable response/support from a sub along with room gain.

Room gain will be unique for you room. It is not unusual to begin getting some gain ~120 to 150 Hz and more with decreasing frequency.

Through your modeling you can move the area under the curve. Some of the energy at the lowest frequencies of your model might be better spent raising the response from ~70 or 80 Hz (or higher) to match the level of the mid frequencies.

This allows both the sub and mid-woofer to work in the ranges where they do their best...arriving at a "flat" overall response.

[Mayhem13]

Hey Zilch....does a horn like this help to align the acoustic centers since it's offset? I just thought these might look pretty cool backmounted behind some nice figured walnut baffles.....sorta the JBL Synthesis look but if they're crap then they're crap no matter how good they look.

[Zilch]

A horn like what?

[Mayhem13]

Sorry...it was late.

http://www.parts-express.com/pe/show...umber=292-2574