Flex Your PCD Mettle:

[Zilch]

Re: Distortion Measurements:

That tweeter distortion level is mighty small indeed.

With a 1W/1m sensitivity of 108.5 dB, even with the requisite HF comp, it's running on milliwatts there.

[Yeah, biampably.... ;) ]

[Zilch]

Re: Flex Your PCD Mettle:

The pair:

[Pete Schumacher]

Re: Flex Your PCD Mettle:

The pair:

Well? How about a listener description of what you've auditioned?

[Zilch]

Re: Flex Your PCD Mettle:

Well? How about a listener description of what you've auditioned?

We've quite stepped in it with this combo.... :D

[Dennis H]

Re: Flex Your PCD Mettle:

Nice job, Pete and Zilch, with the minimalist XO!

About the Kappalite distortion, I'm inclined to trust Brandon's measurement which looks a lot better at LF than what Zilch measured. He mounted it on a large OB, 100dB at 30", mic at 15".

http://493531664873718246-a-1802744773732722657-s-sites.googlegroups.com/site/drivervault/driver-measurements/tang-band-75-1558se/eminence-kappalite-3012ho/non-linear-distortion-1/HD_sweep.PNG?attachauth=ANoY7coHhgJC1kyZ6RgB7NQOSOr-mDGj3eiKZNYGjaCUfCa69ngbbsHEZCNE3wke2zpGimisiCqAHHUYbRZswD0Wyd2e-FqXjQfIER-z-Ss_oklApMWpTbvdWppR4fJswVQ28ND8546nX2N7QKaIEL_q5dHzmzitc12b-YKluJJGcK0M3wkTPb--vh7sKpyne4bq8Istl6qFAUJXxNWoty-Bw428BTOVaDrOTsFwab85kprwo6T5MGYeK4iBOUMIL1SMcqk-66iN4P-1ffBJZ4qwcJqncrbj7HdYprFEFhHIt27darDy7zCpmVTLCd_Y6WLbRH3evtQl&attredirects=0

[Pete Schumacher]

Re: Flex Your PCD Mettle:

Nice job, Pete and Zilch, with the minimalist XO!

About the Kappalite distortion, I'm inclined to trust Brandon's measurement which looks a lot better at LF than what Zilch measured. He mounted it on a large OB, 100dB at 30", mic at 15".

http://493531664873718246-a-18027447...attredirects=0

I kind of figured that room effects could be causing that. Everything I'd seen on the Kappalites showed excellent performance, as in the attachment you linked to.

[Zilch]

Constant Directivity RULEZ!

Here's the vertical polar map of the PAIR, taken at 22.5° off-axis horizontally:



That's about where we listen to them if they're not toed-in, and the response in the Geddes extreme toe-in alignment. Looks like we're good (-6 dB) to very nearly +/- 15° from the 2.6° upwardly-tilted forward axis....

[Pete Schumacher]

Re: Constant Directivity RULEZ!

Here's the vertical polar map of the PAIR, taken at 22.5° off-axis horizontally:



That's about where we listen to them if they're not toed-in, and the response in the Geddes extreme toe-in alignment. Looks like we're good (-6 dB) to very nearly +/- 15° from the 2.6° upwardly-tilted forward axis....

Check out this waveguide loaded (PE 10") SB Acoustics ring radiator. Care of Zaph.



And with a single 5.6uF capacitor. 15deg off axis



This could be an alternate top end for this particular woofer.

[Zilch]

Re: Flex Your PCD Mettle:

DRAT!

Now I gotta measure the horizontals....

:D

[Zilch]

Re: Flex Your PCD Mettle:

There's directivity, and then there's CONSTANT directivity. ;)

This waveguide is spec'd 90° horizontal and 50° vertical (-6 dB). See Brandon's horizontal measurements for the same combination driver/waveguide:

http://sites.google.com/site/drivervault/driver-measurements/horns-and-waveguides/qsc-pl-000446-gp

He measured in 7.5° increments, 0° - 67.5°. His cyan is 45°, representing the 90° spec.

I confirm his findings with these system measurements, taken at the forward vertical axis, 0° - 45° in 5° increments:

[Pete Schumacher]

Re: Flex Your PCD Mettle:

There's directivity, and then there's CONSTANT directivity. ;)

This waveguide is spec'd 90° horizontal and 50° vertical (-6 dB). See Brandon's horizontal measurements for the same combination driver/waveguide:

http://sites.google.com/site/drivervault/driver-measurements/horns-and-waveguides/qsc-pl-000446-gp

He measured in 7.5° increments, 0° - 67.5°. His cyan is 45°, representing the 90° spec.

I confirm his findings with these system measurements:


Disclaimer: I don't have a turntable, and did these with a protractor, attempting to maintain the acoustic center on the test stand....

Those sure are consistent plots. I'm really looking forward to hearing these some day.

You know if anyone is doing one of these in the Indiana area? Maybe bring one to InDIYana?

[Zilch]

EconoWave Deluxe:

[NWCgrad]

Re: Flex Your PCD Mettle:

Zilch,
Just ordered three of the QSC waveguides. Plan on building w/ the XO and drivers from this thread (also following on AK).

Did you port the cabinet?
How picky is the XO to this cabinet, I would like to build my own since I have a bunch of leftover 3/4" baltic birch left over from a recent subwoofer build (I would like to build a rectangular cabinet to blend w/ my subwoofer)?
Would a supertweeter help (due to the roll off over 15 kHz) or hurt the overall sound?

Overall this looks like a fun project, should easily beat the sound of my 16 yr old Paradigm 9seMkIII's.

SWN

[Pete Schumacher]

Re: Flex Your PCD Mettle:

Zilch,
Just ordered three of the QSC waveguides. Plan on building w/ the XO and drivers from this thread (also following on AK).

Did you port the cabinet?
How picky is the XO to this cabinet, I would like to build my own since I have a bunch of leftover 3/4" baltic birch left over from a recent subwoofer build (I would like to build a rectangular cabinet to blend w/ my subwoofer)?
Would a supertweeter help (due to the roll off over 15 kHz) or hurt the overall sound?

Overall this looks like a fun project, should easily beat the sound of my 16 yr old Paradigm 9seMkIII's.

SWN

If you keep the baffle width the same, then the XO should work without any changes.

The cabinet Zilch uses isn't optimal for an un EQ'd driver for bass since he plans on adding boost. If you're not going to actively EQ the low end, you may want to alter the cabinet to extend the low end that way.

[NWCgrad]

Re: Flex Your PCD Mettle:

If you keep the baffle width the same, then the XO should work without any changes.

The cabinet Zilch uses isn't optimal for an un EQ'd driver for bass since he plans on adding boost. If you're not going to actively EQ the low end, you may want to alter the cabinet to extend the low end that way.

Thanks for the information. Planning on staying passive. Looking at the specs for the woofer it seems that a larger enclosure (maintaining the same baffle width) would be the way to go to extend the low end. I see the recommended enclosure volume is 1.3-3.0 cu.f.t; am I correct that the low end extends as you approach 3.0 cu. ft.? Does this change the upper frequencies of the woofer's response?

Just as an aside, could another woofer be used as the L-pad can match the levels? (I am assuming NOT, but we all know what happens when you assume).

Lastly, would an air core inductor (such as the Jantzen 4.5mH 18 AWG Air Core Inductor [Sku 255-282]) offer any sonic advantage over the ERSE I-core inductor? The cost differential for 2 isn't that much.

Thanks for the reply! Trying to minimize cost, while maximizing quality. I only upgrade speakers about once a decade, so I have to get it right when I do.