Flex Your PCD Mettle:

[Pete Schumacher]

Re: Flex Your PCD Mettle:

O.K., I'll notch out the spike and fix the directivity, then provide new measurements so Pete can make it play flat as Nebraska.... ;)

I always found Eastern Colorado to be as flat as any place I've ever seen. Central Illinois is right in there.

Nebraska does more resemble a typical tweeter response, little bumps and hills.

Seriously though Zilch, that is one fine looking set of components. And that L-pad makes it a cinch to dial it in for sure.

[Mayhem13]

Re: Flex Your PCD Mettle:

Smoothe..yes. Econo?..........That would depend on your tax bracket.:D How bout Obamawave?

[Zilch]

Re: Flex Your PCD Mettle:

Smoothe..yes. Econo?..........That would depend on your tax bracket.:D How bout Obamawave?

EconoWave is full spectrum in $70 Dayton cab kits. ;)

Several AKers have already built with this driver/waveguide combo, actually; it'd be good if we had an optimized crossover for it....

[NEO Dan]

Re: Flex Your PCD Mettle:

Smoothe..yes. Econo?..........That would depend on your tax bracket.:D How bout Obamawave?

Speaking of Econo; I've had something on my mind for a bit:


Had anyone considered the QSC CDX1-1425, or the $52 CDX1-1415? I know it's not a ballsy driver but if it's got a usable low end that could mate up with a 15" driver like say the DeltaLite II 2515 for some efficient & light weight monitors.

[Zilch]

Re: Flex Your PCD Mettle:

Had anyone considered the QSC CDX1-1425, or the $52 CDX1-1415? I know it's not a ballsy driver but if it's got a usable low end that could mate up with a 15" driver like say the DeltaLite II 2515 for some efficient & light weight monitors.

http://techtalk.parts-express.com/sh...89#post1647589

As with all of the links in the first post of this thread, the target post is the culmination of that particular effort. You've got to scroll/page back to see where it began and how we got there....

[NEO Dan]

Re: Flex Your PCD Mettle:

http://techtalk.parts-express.com/sh...89#post1647589

As with all of the links in the first post of this thread, the target post is the culmination of that particular effort. You've got to scroll/page back to see where it began and how we got there....

I remember that - someone was on a mission to kill Nathan :D very focused they were ;)

I was suggesting a CDX1 series driver on the 152i WG may go well with a 15" driver WRT AC and forward lobe. I'm curious if the design of the CDX1 throat will help it hold up better in the LF, it looks a lot stronger and has a cleaner CSD than the DE250. Something potentially better than a DE250 for $52 and the commercial account price on the DL II 2515 is very - Econo :D

[Zilch]

Re: Flex Your PCD Mettle:

I have a pair of the CDX1-1731 that Duke is using in his product, but haven't tried them yet; -1730 is the bolt-on variant and appears to be popular. Penn and I went 'round and 'round about -1425 and how low it might suitably be used. I'm very much put off by the factory spec minimum recommended crossover frequency. In the end, all factors considered, I believe my view prevailed.

You know my perspective on 15" woofers and waveguides, though Wayne disagrees, and Brandon recently demonstrated that 152i has usable pattern control down to 1 kHz with a suitable driver, which I suspect means having a "correct" exit angle. I'm tempted to mount a 2-bolt JBL 2425H on one and see what happens, i.e., if I can replicate Brandon's findings. If so, that moves us into 4430 territory with 15s in 4507 cabs, and I'm certainly not above taking that delicious ride.... :p

[Zilch]

Re: Flex Your PCD Mettle:

So much for the spike:

[NEO Dan]

Re: Flex Your PCD Mettle:

I have a pair of the CDX1-1731 that Duke is using in his product, but haven't tried them yet; -1730 is the bolt-on variant and appears to be popular. Penn and I went 'round and 'round about -1425 and how low it might suitably be used. I'm very much put off by the factory spec minimum recommended crossover frequency. In the end, all factors considered, I believe my view prevailed.

You know my perspective on 15" woofers and waveguides, though Wayne disagrees, and Brandon recently demonstrated that 152i has usable pattern control down to 1 kHz with a suitable driver, which I suspect means having a "correct" exit angle. I'm tempted to mount a 2-bolt JBL 2425H on one and see what happens, i.e., if I can replicate Brandon's findings. If so, that moves us into 4430 territory with 15s in 4507 cabs, and I'm certainly not above taking that ride.... :p

2425H is an interesting choice, I'm sure the CSD will be quite a sight to behold. You can get the same level of awesomeness from the D220ti, why bother?

[Zilch]

Re: Flex Your PCD Mettle:

They're spec'd down to 500 Hz....

[NEO Dan]

Re: Flex Your PCD Mettle:

They're spec'd down to 500 Hz....

I think it's 800 Hz actually. On a specific horn with a specific crossover...:rolleyes: so methinks YMMV

It would be nice to see a comparison of the two drivers on the 152i WG:D

[Zilch]

Re: Flex Your PCD Mettle:

Your HOLM is broke, too?

[EVERYBODY's HOLM is broke, apparently.... :eek: ]

[NEO Dan]

Re: Flex Your PCD Mettle:

I don't have the drivers. Though I've got the DL II 2515. I did have HOLM working, I could probably manage to build another PC to get it going again.

I think the reason the Celestion compression drivers are so conservatively rated is the test method:
"Tested for two hours on plane wave tube using a continuous, band-limited pink noise signal as per AES standard. Power calculated on minimum impedance."

I C the JBL is de-rated to 20 watts at 500 Hz.

[carlspeak]

Re: Flex Your PCD Mettle:

Your HOLM is broke, too?

[EVERYBODY's HOLM is broke, apparently.... :eek: ]

]

Mine's not broken....

KLH-17 econo-wave on axis response and impulse response.

[edlafontaine]

Re: Flex Your PCD Mettle:

Zilch posted:
..., and Brandon recently demonstrated that 152i has usable pattern control down to 1 kHz with a suitable driver, which I suspect means having a "correct" exit angle.

My investigation with paper gages tell me the mouth entry angle of the 152i horn is:

Vertical ~32.5 degrees;
Horizontal ~60 degrees;

When you compare these to the DE250's exit angle of 14.6 degrees you can begin to appreciate the room for improvement.
Comparing these graphically with Geddes' OS profile tells me I need to add ~3/16" between the CD and horn...and smooth.
The smoothing needs to be extended out into the throat. There is a slight concavity to be dealt with up to around 1" into the horn. One can feel it and it is visible by letting sunshine through the throat. Rotate it slowly.

The shadows know. ;)