Flex Your PCD Mettle:

[stgdz]

Re: Flex Your PCD Mettle:

Zilch, I apologize if this has been asked.

But how do I set the L-pad adjustment dial. Do I just set it in the middle and use the ears to see what I like? Does the level depend on the build?

[Zilch]

Re: Flex Your PCD Mettle:

Has anyone done a MTM arrangement with the Econowave?

None yet, and we have no data on how they might behave. Others have inquired about horizontal MTM for center channel, and we have discouraged the approach, though here, too, we have no hard data.

But how do I set the L-pad adjustment dial. Do I just set it in the middle and use the ears to see what I like? Does the level depend on the build?

In all of the builds in this thread, we have designed with the L-pad set to the 1:00 position. The original generic crossovers anticipated use with a variety of woofers with two basic variants based upon woofer sensitivity, low (< 95 dB) and high (>95 dB), and level depended more upon the build. In any case, adjust to taste and room....

[Flacjunky]

Re: Flex Your PCD Mettle:

Others have inquired about horizontal MTM for center channel, and we have discouraged the approach, though here, too, we have no hard data.

I'm hoping at some point you do experiment with some form of horizontal layout.

So I can quit "inquiring"..... and start cutting out some holes in my baffle. ;)

What about commercial Floor Monitors? What do they do to address the nulls?

Or are the nulls a feature and not a bug in such applications?

[Zilch]

Re: Flex Your PCD Mettle:

I'm hoping at some point you do experiment with some form of horizontal layout.

So I can quit "inquiring"..... and start cutting out some holes in my baffle. ;)

What about commercial Floor Monitors? What do they do to address the nulls?

Or are the nulls a feature and not a bug in such applications?

It's a feature; they want narrow horizontal dispersion and ideally, asymmetric "vertical."

[bwaslo]

Re: Flex Your PCD Mettle:

Has anyone done a MTM arrangement with the Econowave?
Or does that add to the null problems?

I did an MTM test and the nulls were very problematic using much smaller woofers then yours. The problem came up below crossover -- where the tweeter gives out, you now have a very large center to center distance between the two woofers and the vertical pattern becomes really narrow.

Putting two drivers side by side below the waveguide at crossover worked well, though. I was using 5.25" drivers, though, two tens would look something like a 20" driver horizontally, and would be pretty narrow horizontally then where it is supposed to meet up with the waveguide. You could put the woofers vertically below the guide, and not cross the lowest one in till about 300Hz, as a baffle step correction -- but only if you'll be using the speakers out away from the wall I'd think.

[Zilch]

Re: Flex Your PCD Mettle:

The two 2432H I have are factory new in box; here they are on the same crossover in comparison to the (Red) design 2452H-SL:



And here's the lot:

[Mayhem13]

Re: Flex Your PCD Mettle:

Looks lile another possible WG element......not the cheapest but...

http://www.parts-express.com/images/item_standard/294-800_s.jpg

[Zilch]

Re: Flex Your PCD Mettle:

EconoWave HP variant A with JBL 2432H HF driver succumbed (+/- 1.5 dB) to tweakage via PCD, in the course of which, the forward axis moved up to +0.65° above the midpoint between woofer and waveguide:



The vertical polars are among the best we have achieved here, with a usable (-6 dB) listening window spanning -10° to +15° about the forward axis:




Assuming the factory specs are directly applicable, this design has a system sensitivity of 95 dB and a max continuous SPL rating in excess of 120 dB:

http://www.jblpro.com/catalog/general/Product.aspx?PId=317&MId=2

[dantheman]

Re: Flex Your PCD Mettle:

So if your speakers are 9ft away, you've essentially got over a 4ft vertical window by the -6dB points. Or at 6ft you've got 2ft 9+inches. Plenty IMO.

Dan

[Zilch]

Re: Flex Your PCD Mettle:

Yes, by my rough calc, the difference between me sitting and standing at a 10' listening distance is +10°, which I consider rule-of-thumb minimum acceptable height for a usable forward lobe.

The shorter the lobe, the more precisely it must be steered to the listening axis. In most of the larger designs in this thread, the center-to-center distance between woofer and waveguide clusters around 10.5", and we have easily met this criterion with acoustic crossovers in the 1.5 - 1.8 kHz range. Delite 10e approached the limit at 2.14 kHz. Builds with narrower C/C distances can go to higher XO frequencies.


Footnote: Don't know if everyone gets this part, but the vertical locus of the system acoustic center is the midpoint between drivers, independent of the "z" offsets, which is why I design with that in consideration. The tweeter axis has an inherent angular "y" offset from there, which varies with listening distance....

[Zilch]

HPA+ Horizontal Directivity

We could probably achieve a smoother transition by moving the crossover frequency up, but would sacrifice some forward vertical lobe height achieving that. I believe there is more yet to be accomplished with baffle improvements, so I'm leaving it be for now:

[Zilch]

HPA+ Horizontal Directivity, Continued

The normalized views:

[Mayhem13]

Re: Flex Your PCD Mettle:

Anyone E-waved with this yet?



http://eminence.com/proaudio_speaker...ail_link=DELTA PRO-12A&speaker_size=12&SUB_CAT_ID=1

Very efficient and mfgrs measurments are pretty close to Klite12H0. Bass extension isn't as deep though....but for sub users...:D Chassis depth and i suspect AC is about 1" deeper than Klite so an easier mate to the 152i guide. Here's a Unibox sim ported........

[dantheman]

Re: Flex Your PCD Mettle:

You might be able to get that woofer to work if crossed low enough.
polar graph in 11.25 degree steps:


Dan

[Mayhem13]

Re: Flex Your PCD Mettle:

You might be able to get that woofer to work if crossed low enough.
polar graph in 11.25 degree steps:


Dan

Standard E-wave fair is 1.6khz....low enough?

Where'd you get the polars from?