Flex Your PCD Mettle:

[penngray]

Re: Flex Your PCD Mettle:

Yes and yes; we can probably grab as much as 1.5 dB more. It's set at 1:00, and up to 3:00 would be fine.

C/c distance is 10.6875".

For wavelet heads:

Cool, Im a wavelet head that geddes doesnt like :D

[Zilch]

Delite 10e Second Attempt:

Forward axis = +3.01°, drivers in-phase:



[2:41 AM.... :p ]


Vertical polar maps:





Compare to Delite 10 w/XT1086:

http://techtalk.parts-express.com/attachment.php?attachmentid=8246&d=1271575232

[W/10.69" c/c and 2.16 kHz XO, the forward lobe is getting short; still usable, though.... ]

[Skywave-Rider]

Re: Flex Your PCD Mettle:

Wow performance on a 6 buck part.
Nice how the Celestion tapers off at the high end.

For comparo, is red the measurement axis on the XT1086 graph?

Thanks for doing this.:D

[Zilch]

Re: Flex Your PCD Mettle:

Wow performance on a 6 buck part.
Nice how the Celestion tapers off at the high end.

For comparo, is red the measurement axis on the XT1086 graph?

Yes, red is the first button in CLIO, and thus, the forward axis in vertical polar maps, unless otherwise stated. :p

In this case, it's +3° from the midpoint between the drivers, so the up direction runs into its null sooner (Lt. Gry).

The PCD sim on this round is nearly perfect:



Crossover (preliminary):

[Zilch]

Re: Flex Your PCD Mettle:

Pete requested some additional measurements with the L-pad set at 3:00 in lieu of 1:00, which are attached below.

Also, here are the offsets as I presently have them, on the forward axis:

[Zilch]

Re: Flex Your PCD Mettle:

With Pete's suggested mods:



Both drivers normal polarity.

Forward axis moves down 0.33° @ 1:00.

[Pete Schumacher]

Re: Flex Your PCD Mettle:

Had to adjust things because I had the acoustic offset reversed, with the woofer behind the tweeter.

Added a bit of BSC

Woofer XO:

1.8mH .3 Ohm
15uF
.4mH .2 Ohm

Tweeter XO:

4uF
.15mH .2 Ohm
3.3 uF in parallel with 1.8 Ohm before the XO.
change 2.7uF to 3.3uF in notch circuit.

I'm using Jeff's latest version of PCD with the corrected vertical spinners and sign switched acoustic offset.

So 7 degrees above tweeter axis appears to be the design axis where the deep reverse null occurs.

[scitizen17]

Re: Flex Your PCD Mettle:

Looking forward to seeing the data posted here.

I am unfamiliar with that horn. May we have a link, please?

Here are plots I ran today. 1 meter on axis with crossover. The composite plot is with smoothing N=3.

[Zilch]

Re: Design Axis:

Our waveguide axis is 5.3438" above the midpoint between woofer and waveguide. At an 8' listening distance, that'd be arctan 5.3438/96 = 3.1860°, and at 10', 5.3438/120 = 2.5498°, assuming we are listening at waveguide height, per normal practice. That's where I target the design axis.

Standing, I'm 22", or arctan 22/120 = 10.3889° higher at 10' listening distance.

It'd be good if there was no hole in the response there.

[OR at reasonable angles below the waveguide axis, either.... ]

[Zilch]

Re: Flex Your PCD Mettle:

That's certainly looking good, Scitizen.

Try some off-axis measurements, say, in 10° increments; they don't tell us the dispersion pattern of that horn anywhere that I could see....

[scitizen17]

Re: Flex Your PCD Mettle:

That's certainly looking good, Scitizen.

Try some off-axis measurements, say, in 10° increments; they don't tell us the dispersion pattern of that horn anywhere that I could see....

From the documentation I have read, the best way to perform the off-axis measurements is to rotate the speaker while leaving the mic stationary.

Do you agree?

Thanks, Scott

[Zilch]

Re: Flex Your PCD Mettle:

Yup, as that retains everything else constant.

[I don't always do that, though, for verticals, particularly, over a narrow range.... ]

[Zilch]

Revised per Pete's 2nd recommendation, supra:



The code:

Forward axis = Red
Down toward woofer = Grn, Blu, Vio, Cyn
Up toward wavegude = Org, Yel, Gry, Lt. Gry



Compare here: http://techtalk.parts-express.com/at...2&d=1274641362





Nearfield low frequency response:





[Done, I'd say.... ]

[Zilch]

OLA 122i CDX1-1425 Horizontal Polar Response

Unfiltered and uncomped (at waveguide axis):



15° is Yel, 30° Vio, 45° Blk.


With our Delite 10e highpass and HF comp (at waveguide axis):




Woofer only w/Delite 10e lowpass (at forward axis):




Total system (at forward axis):




60° beamwidth:



Compare to Geddes 10" Nathan:

http://www.gedlee.com/Nathan.htm

15° = Grn, 30° = Blu, 45° = Red

[Pete Schumacher]

Re: Revised per Pete's 2nd recommendation, supra:

The code:

Forward axis = Red
Down toward woofer = Grn, Blu, Vio, Cyn
Up toward wavegude = Org, Yel, Gry, Lt. Gry



Compare here: http://techtalk.parts-express.com/at...2&d=1274641362




[Done, I'd say.... ]

Looks pretty good overall . . .

How's it sound?