Flex Your PCD Mettle:

[edlafontaine]

Re: Flex Your PCD Mettle:

I was going to point these out to you until you told me you have the 2510's ;)

http://www.mcmelectronics.com/product/MCM-AUDIO-SELECT-55-2961-/55-2961

They're on sale for $15

...and I forgot to mention the "Geddes" foam below...so it is edited in

[bwaslo]

Re: Flex Your PCD Mettle:

Ed,

I wouldn't entirely trust the comments on "honk" or "midrange coloration" from that sighted test. I suspect that a lot of people automatically expect to hear a honk when faced with something that looks like a horn whether its there or not.

I have my ewaves set up right alongside some tall BG Radia fullrange ribbons (because I don't have anywhere else to set those for the moment) and without exception everyone who happened to listen the system for music or movies assumed the ribbons were what they were listening to (and there've been no comments about "honk"). These are non-audiophiles of course (and so, probably more sane but less caring about what it sounds like). But I strongly suspect that the "honk" comment wouldn't have happened at MWAF if the speakers hadn't been visible...

[Zilch]

Re: Flex Your PCD Mettle:

... complicated by the possibility cited that the woofers may actually be generating some "honk," they may be the source of both that and any "midrange coloration."

Tied for second equates to "excellent," in my book. With respect to the overall score, as Bwaslo suggests, a strong bias against horns is generalized to modern waveguides, and at this juncture, only blind comparisons could sort it out. I'd expect we'll get closer to the truth (not that I know what that is) once more examples of the paradigm begin appearing at meets. For now, it's apparent that EconoWaves (and similar) are a "venturesome" endeavor in this realm.... ;)

[dantheman]

Re: Flex Your PCD Mettle:

http://seanolive.blogspot.com/2009/04/dishonesty-of-sighted-audio-product.html

Dan

[donprice]

Re: Flex Your PCD Mettle:

eWave PCD for dummies, round 4

Kappalite 3015 QSC 152i/ B&C DE250

FRD files from HolmImpulse in-room measurements - measured at center of HF/LF at 44" on axis, mic ~60" above floor and below ceiling. Gate value manually set @ 5 ms ~200 Hz for both.

So here's what I get from building the XO I came up with in PCD. Note - measurements were from speaker in listening position (44" on axis, 24" above floor) and not the low WAF middle of floor aimed at ceiling position.

I ordered quite a few spare caps and resistors so tweaking it won't be too difficult. The second graph was generated using the "LE 14 optimized" eWave crossover that was already installed in the box. I figured it would be a good reference point - see what using the XO for the wrong HF driver looks like. Actually, I think it looked better than my custom attempt. The drop off in the HF tells me I made a pretty big mistake somewhere. L-pad is wide open.

The third graph overlays the two different XOs and includes the HF phase reversed.

PCD design info back at post # 623....

I think I need to burn a vacation day tweaking away in the living room. Now I'm starting to sound like a chicken-necked meth freak.;)

[Zilch]

Re: Flex Your PCD Mettle:

Fun stuff!

It's how we figure this out....

[stgdz]

Re: Flex Your PCD Mettle:

So I finished one of my 10e crossovers last night




I will need to fix the placement of the inductors though tonight but other then that does everything look correct? The black and white wire shown connected up is the +/- input wire.

1 goes to the 1 tab on the lpad
2 isn't shown but will go to the - on the tweet.
3 connects to the 3 tab on the lpad, the input -, and the woofer negative(I have three wires going into 3)

I typically build crossovers starting with the positive and work my way around to the negative side.

[Zilch]

Re: Flex Your PCD Mettle:

You have C2 and C3 reversed, looks like; the big guy belongs in the lowpass filter....

[Flacjunky]

Re: Flex Your PCD Mettle:

First off, I want to thank you guys for tolerating my ignorance up to this point. I have actually learned quite a bit during my time on this forum, and particularly this thread.

At first you guys might as well have been speaking Klingon here, for all I could tell, but now I kinda get what you are saying ..... at least sometimes. :o

A few months ago I would have never considered making my own crossover, but now that I've built some in my mind, I think I'm ready to buy a soldering iron. I wish I had more time to learn, but now I cant go any further on my listening room / HT until I get the main cabinet stuffed with drivers. I have to order parts for either an econowave, or a WMTM this week, and crunching the numbers, the Econowave is my best choice.

I hate to keep asking the same basic question over and over, but I'm really confined by my architectural constraints. I appreciate the good advice you've given me in the past, but I just dont have the option of taking it all.

I mentioned before that baffle was 27" Wide x 21" Tall, but after taking them off for the first time in years, I really only have 24" Wide x 16" Tall to work with without taking a sawzall to the bracing.

So I really have to go with a horizontal side by side setup. Keep in mind there is no such thing as off-axis in my room. Its a single seat, fixed, listening point environment. I cant sit anywhere in this room where my ears wont be within 5 degrees of being on axis of the acoustic center, and between 6 to 8 feet away from the speakers. I am prepared to accept the fact that a horizontal setup has undesirable issues, but I need to hear them for myself, to determine whether the degradation is acceptable. If not I will rip them out and build a vertical setup for my son's room.

I want to stay with a proven Zilchlab design, such as the SR option, but that QSC waveguide, aside from being apparently unavailable? at this time, is gonna look kinda stupid in a vertical orientation. I want to substitute this Square / Rotatable one in its place.... or any square rotatable one you care to suggest.

So I'm looking at ordering the Dayton 12" Pro Woofer, the Selenium screw on CD, and the Dayton H110 waveguide, and using them in an on-wall, horizontal setup.

Which one of your crossover designs do you think would work best in such a setup?

[Mayhem13]

Re: Flex Your PCD Mettle:

Not sure exacly what you're looking to do but here's a build using a large format horn with two side by side woofers below. It's actually a rebuild of a very high end TAD monitor. This format is still popular in monitoring labs throughout. I believe you have to call QSC parts to get the 152i guide and AFAIK it's currently available. Such a design would work with two 16ohm woofers in parallel below but may require some tweaking of the E-wave XO for level matching depending on the sensitivity of the woofers. I think such a design has excellent potential UNTIL you said you wanted to put in ON the wall.........nonononononono!:eek: Worst midbass response imaginable regardless of the design. if you must do something like this, do it in wall or if you don't have the depth fashion some sort of extended baffle plane on a curve to meet the existing wall. Here's a pic

[Mayhem13]

Re: Flex Your PCD Mettle:

Hey Zilch, that little Ewave to the right in this photo........



Is that the RCF 101?

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=294-800

And if so, how did it measure? MFGR says effective loading to 1khz???

Nevermind......side by side it clearly isn't...sorry.

[Zilch]

Re: Flex Your PCD Mettle:

Which one of your crossover designs do you think would work best in such a setup?

Without measurements, it's somewhat of a crap shoot. Skew the odds in favor of a successful outcome by mating the lowpass developed for whatever woofer you're going to use with the original Econowave highpass, high-efficiency variant, for the greatest flexibility.

Hey Zilch, that little Ewave to the right in this photo........

JBL OASR, the "Dr. Seuss" waveguide.

"Loading" doesn't apply here -- it's pattern control what matters in waveguide designs.

1 kHz? Ain't happenin', nope....

[Flacjunky]

Re: Flex Your PCD Mettle:

Skew the odds in favor of a successful outcome by mating the lowpass developed for whatever woofer you're going to use with the original Econowave highpass, high-efficiency variant, for the greatest flexibility.

Gotcha ..... Thanks Zilch.

[Flacjunky]

Re: Flex Your PCD Mettle:

Not sure exacly what you're looking to do but here's a build using a large format horn with two side by side woofers below. It's actually a rebuild of a very high end TAD monitor. This format is still popular in monitoring labs throughout. I believe you have to call QSC parts to get the 152i guide and AFAIK it's currently available. Such a design would work with two 16ohm woofers in parallel below but may require some tweaking of the E-wave XO for level matching depending on the sensitivity of the woofers. I think such a design has excellent potential UNTIL you said you wanted to put in ON the wall.........nonononononono!:eek: Worst midbass response imaginable regardless of the design. if you must do something like this, do it in wall or if you don't have the depth fashion some sort of extended baffle plane on a curve to meet the existing wall. Here's a pic

Interesting layout.

I was married to 15" woofer originally, but now that I have the twin 15" subs below, the dual smaller woofers are not out of the question.

If I subtracted the QSC wavequide's height? from my available 16", I might be able to squeeze Dual 10" Woofers in there.

....... It would certainly look cool. ;)

I cant do anything about the "On-Wall" at this time, but I do have 7.5 cu. ft. of cabinet to play with.

.... has anyone at AK published a crossover design for such a setup?

[Mayhem13]

Re: Flex Your PCD Mettle:

Dual 10's will set the drivers center to center spacing too far from the center of the guide at the 1.5khz XO frq. You'd need to cross 1khz or lower.....to low for the 152i guide to hold pattern control. Think 8" or lower....two 40hm 8" woofers. Here's an excellent candidate....not as sensitive as the Ewave flavor but sonically.....excellent off axis response to 2khz!

https://www.madisound.com/store/product_info.php?cPath=45_228_257&products_id=8771

Would also make for an excellent MTM!