Flex Your PCD Mettle:

[greywarden]

Re: Flex Your PCD Mettle:

You'd really need to take measurements and put them into PCD...

[Skywave-Rider]

Re: Flex Your PCD Mettle:

Finally got PCD running, halleluiah!

[Skywave-Rider]

Re: Flex Your PCD Mettle:

Is there an advantage to offsetting a small waveguide like the JBL 6x6 in a baffle, in the way many dome tweeters are, to help minimize baffle effects? Or is this not needed since there is directivity control?

Does PCD model this?

[mike price]

Re: Flex Your PCD Mettle:

"If you run the two LE14a's in parallel you'll gain 6db of sensitivity , which is a good thing. You will want to build it as a 2.5 way though , to avoid comb filtering effects which will result from the bottom woofer being too far from the tweeter for the 1.6k crossover frequency. This can be implemented with the addition of a single coil added between the two woofers."
Could you avoid the comb filter effect by putting one woofer on top of the waveguide and the other below. a/k/a MTM? Would this screw up the crossover designed for only one woofer. Phil

That would work as well , drawback being that the top woofer will be pretty high up to still keep the tweeter on axis at listening height.

[figure8]

Re: Flex Your PCD Mettle:

"If you run the two LE14a's in parallel you'll gain 6db of sensitivity , which is a good thing. You will want to build it as a 2.5 way though , to avoid comb filtering effects which will result from the bottom woofer being too far from the tweeter for the 1.6k crossover frequency. This can be implemented with the addition of a single coil added between the two woofers."
Could you avoid the comb filter effect by putting one woofer on top of the waveguide and the other below. a/k/a MTM? Would this screw up the crossover designed for only one woofer. Phil

[smokarz]

Re: Flex Your PCD Mettle:

hey guys, is there a big performance diff between the Standard and SR versions?

the Standard can be build for roughly half of what it cost to build the SR.

thinking of building a cheap waveguide for center duty, and the Standard seems to fit the bill well. the SR is also another good option, but if there's no major performance gap between the two, then why build something that cost almost 2x more?

thanks

[CZ Eddie]

Re: Flex Your PCD Mettle:

If you run the two LE14a's in parallel you'll gain 6db of sensitivity , which is a good thing. You will want to build it as a 2.5 way though , to avoid comb filtering effects which will result from the bottom woofer being too far from the tweeter for the 1.6k crossover frequency. This can be implemented with the addition of a single coil added between the two woofers.

Thanks for the reply.
I've heard a lot of bad things about 2.5 ways.
Probably best to just stick with a simple 2 way and skip the second LE14A.

[mike price]

Re: Flex Your PCD Mettle:

Thanks, not sure how I missed that. The 4, 8 & 16 ohm version crossovers do have different components.



My thinking was to pair the 8ohm QSC + D220ti top with a LE14A bottom crossover. But instead, to have a pair of LE14A's per speaker (vertical mounted) instead of just one per speaker.
Thing is, I think even the 16ohm versions of the LE14A's are actually more like 8ohm.. Which would make the pair either 4 ohm or 16 ohm, depending on wiring. Wasn't sure how that would work out.

If you run the two LE14a's in parallel you'll gain 6db of sensitivity , which is a good thing. You will want to build it as a 2.5 way though , to avoid comb filtering effects which will result from the bottom woofer being too far from the tweeter for the 1.6k crossover frequency. This can be implemented with the addition of a single coil added between the two woofers.

[CZ Eddie]

Re: Flex Your PCD Mettle:

http://home.comcast.net/~dnewma04/EconowaveBoM.htm
Here is a link to the parts but I think the variations are for the woofers- not sure of top end.

Thanks, not sure how I missed that. The 4, 8 & 16 ohm version crossovers do have different components.

The HF sections of the Econowaves are Driver/Waveguide specific. The woofer sections vary greatly , and were intended to be tweaked by the builder to match up properly with one of the HF variants , unless you're using one of the complete designs outlined on the first page of this thread. I don't think there would be any problem using a 16ohm woofer with one of the E-wave HF sections , but the CD/Waveguide should remain one of the proven designs .

My thinking was to pair the 8ohm QSC + D220ti top with a LE14A bottom crossover. But instead, to have a pair of LE14A's per speaker (vertical mounted) instead of just one per speaker.
Thing is, I think even the 16ohm versions of the LE14A's are actually more like 8ohm.. Which would make the pair either 4 ohm or 16 ohm, depending on wiring. Wasn't sure how that would work out.

[david_b]

Re: Flex Your PCD Mettle:

Could the Econowave S-8 version be built as specified with the specified drivers and crossover, but instead of a sealed box, using a vented box with about .5 or .6 cubic foot volume and a tuning frequency in the 70 - 80 hz range? According to WinISD this gives a F3 between 70 and 80 HZ. Would this require changing the crossover (I would think not, as long as baffle width is roughly same, but am unsure...)

Could it take 225 W in this configuration, as spec'd?

I am hoping that this will give the option for getting more bass out of it when I don't need full power, and then when I need more power maybe I could just hi-pass it? Or maybe I could just plug the port which would give a system with Qtc of .62 in .5 cubic foot box.

[mike price]

Re: Flex Your PCD Mettle:

The HF sections of the Econowaves are Driver/Waveguide specific. The woofer sections vary greatly , and were intended to be tweaked by the builder to match up properly with one of the HF variants , unless you're using one of the complete designs outlined on the first page of this thread. I don't think there would be any problem using a 16ohm woofer with one of the E-wave HF sections , but the CD/Waveguide should remain one of the proven designs .

[spongebob2]

Re: Flex Your PCD Mettle:

http://home.comcast.net/~dnewma04/EconowaveBoM.htm
Here is a link to the parts but I think the variations are for the woofers- not sure of top end.

[spongebob2]

Re: Flex Your PCD Mettle:

I think there is a 16 ohm xover parts list over on AudioKarma on the first page of the ewave thread.

[CZ Eddie]

Re: Flex Your PCD Mettle:

Just out of curiosity, could 16 ohm CD and woofer be used in place of 8 ohm for otherwise perfected crossovers designed for 8 ohm drivers? What would the downsides be?

[tsloms]

Re: Flex Your PCD Mettle:

thanks,

1) is your box sealed?

2) did you use the original e-wave mini xo?

3) any reasons for not using the selenium cd/wg?

4) did you take any measurements?

The box that I used was ported and tuned to about 65 hertz.

I used the special XO that Zilch designed specifically for the Beta 8A and XD120.

As can be seen in the previous posts the XD120 was only $30 each at the time and was an awesome deal for such a good horn/CD.

I have not taken any measurements yet but they sound great and play very loud.

One thing that I did while building mine was to place the L pad inside the cabinet but lined up with the port so that I can make adjustments on the fly with a long screwdriver. I didn't want to have an external L pad showing.

My next build is using to build 3 front speakers for my theater to replace my Natalie P's. They will be actively crossed with the MiniDSP and using the Faital Pro 12PR300 woofers and B&C DE500 CD's on the QSC horns. It should be fun. :D:D