New Drivers: VWR126X and LD25X

[Henkjan]

Originally Posted by tuxedocivic

Is there a specific dimension you need or something?

no, just want to make my sketchup model of the 3way I'm developping with these (+SDX10) a bit nicer

Originally Posted by mwmkravchenko

Henkjan send me a PM and I can set you up with what we have. The woofer is not sketchup , the tweeter is.

yup, thanks.

[tuxedocivic]

Originally Posted by Henkjan

the 3way I'm developping with these

Wow, nice!

[Henkjan]

Originally Posted by tuxedocivic

Wow, nice!

teaser:

[mwmkravchenko]

Nice job Henkjan.

[planet10]

Originally Posted by Henkjan

teaser:

You willing to pass along that SDX10 model?

dave

[tuxedocivic]

Hey,

I've been playing with some waveguides from CSS (planned for production I believe) for the LD25x. Dave P over on Tech Talk developed them. I had a speaker that uses the Dayton 8" waveguide and SB29 tweeter. This waveguide was a direct drop in. Take a look:

Before (Dayton and SB29)



After (CSS)



Might be hard to tell from the pictures, but the CSS looks a lot better.

I did some measuring and it's improves the LD25x... A LOT! I wasn't sure it bested the Dayton SB29 combo though, at least on paper. So I rigged up my minidsp.

The CSS/LD25x was given a 4500hz BW6db/oct high pass. That's it. No eq. That yielded a 1200hz LR24db/oct acoustic high pass. I worked the twin 8" silver flutes into a good LR4 at 1200hz low pass and dialed in delay. Ok, set. At least in a simulation.

Fired them up and listened to a fair bit of music and a couple movies.

Now the good stuff...

WOW! Well done CSS. This thing is really nice. I've been tweaking my Dayton SB29 combo for months and right out of the gate I'd take the CSS over the SB29. It's close though, but to think I haven't even tweaked.

An important factor is that the waveguide dramatically boosted sensitivity. More than I thought it would. It was singing along around 93db/2.83V/m. NICE! Granted so does the SB.

To describe the sound - smooth, clean, LD = low distortion... yup. Accurate.

Jeff Bagby has messed with this tweeter as well, and he's pointed out that this tweeter has a very clean CSD plot. My measurements have shown a very clean impulse response. I am now convinced this can be quite audible. That's exactly how it sounds. CLEAN. CLEAN. CLEAN.

Here's the unfiltered response in blue with a couple passive filters.



LD25x users... enjoy

[mwmkravchenko]

Great to read your results.

I'm a bit confused as to your crossover numbers. you are not pushing the woofers up to 4500 hertz?

Do any distortion plots?

[tuxedocivic]

I applied a 4500 BW1 filter to achieve a 1200hz LR4 acoustic cross over. The high xo on the tweeter flattens the tweeter response back to how it should look, like my last screen shot. I wouldn't cross those silver flute 8" above 1500hz. Even at 1200hz it was obvious the tweeter was cleaner. This tweeter deserves comparable woofers. The SF are not.

I didn't do distortion plots because they don't mean anything without a lot of extra care in setup. I'd need 3 or 4 reference tweeters. And a way to control SPL for each tweeter. The effort isn't worth it to me.

[planet10]

The original goal that i proposed when Ryan took these away was to see if we could get them to match-up with the natural roll-off of a treated SDX7. The red curve. The tweeter with wave-guide goes so low we might have to choke back the top of the SDX7 a bit. Might well work in conjunction with flattening the top of its range.



dave

[mwmkravchenko]

Interesting idea Dave.

When Dave Pellegrene was trying to make this waveguide I kept pushing him in the direction of even on and off axis response. That goal has been attained almost perfectly.