"Into The Abyss", Tweeters in low places

[BOBinGA]

Pretty cool on the SB21RDC-C0004 ring dome. Cross at 1400 LR2 with 0.1% (?) distortion. I can live with that for a 3/4 inch tweet. Sweet.

[Wolf]

Wolf - I never would have guessed you were a Garth fan!

Didn't really say I was, but I don't know anyone who doesn't know that song. My mom is a country fan, and that was on the radio before I moved out on my own.
I did have to look up the original lyrics to better know the song's structure.

Later,
Wolf

[tom_s]

You did a great job. You could have a future as a lyricist for Weird Al!

[Wolf]

Tom-
I used to do this kinda stuff all the time. I suppose some of the word-smithing comes from my mom, who has had a few poems published locally. Sometimes I'll hear a song, and I'll think- You (the artist) could have done better with a different word in that spot.

Thanks!
Wolf

[Brian Steele]

Look at the odd-order HD at various levels, as this will rise significantly with over-excursion. You should notice a definite "trend", which can in turn be used as a guide for setting the lowest x-over point for the tweeter.

[donradick]

So what's the story on waveguides?
I've seen a lot of builds with the SEOS8 WG, any others that would be good with a dome tweeter?

[Pete Schumacher]

So what's the story on waveguides?
I've seen a lot of builds with the SEOS8 WG, any others that would be good with a dome tweeter?

Augerpro was doing a whole thread on creating 3D printed guides with lots of different tweeters. Really interesting data. Of course there's Zaph's documented use of an off the shelf guide modified to fit the Vifa XT19 I believe. I've done a couple of different CNC guides as have others. So if you have access to a CNC, you definitely have a lot of options.

[donradick]

Thanks Pete. I've got a pair of the old RS28F tweeters, so I'll get a pair of the SEOS 8 WGs and see how it goes from there.

[xmax]

The testing will start soon, I'm rounding up a few other drivers. This thread will be about seeing how low
tweeters can go AND still sound good. Steep crossovers, burly tweeters, waveguides etc will be used to
get the job done. A few more "victims". XT25SC40-04, OT19NC00-04 and OX20SC00-04 pictured
with the SEOS-8 and WG16-25-B (I bored one out to 1.125" for the SB21 and it will now work with
the 3/4" domes)

[xmax]

The XT25SC40-04 can be glued right to the SEOS-8.

[humphreyblowdart]

So what's the story on waveguides?
I've seen a lot of builds with the SEOS8 WG, any others that would be good with a dome tweeter?

There's also the Visaton WG148R, as tested here. It only controls directivity down to ~2.5 kHz and the center-to-center spacing will be greater than with the SEOS, but it can fit on a narrower baffle.

[donradick]

There's also the Visaton WG148R, as tested here. It only controls directivity down to ~2.5 kHz and the center-to-center spacing will be greater than with the SEOS, but it can fit on a narrower baffle.

Thanks,man

[xmax]

There's also the Visaton WG148R, as tested here. It only controls directivity down to ~2.5 kHz and the center-to-center spacing will be greater than with the SEOS, but it can fit on a narrower baffle.

WOW! I did not even know about this, 2 on the way!

[bill poster]

By chance do you have the new peerless tweets? These might be a match made in heaven.

[TMM]

All the variants of the XT25 hate going low - only 0.1mm xmax.

SB29 and DA25TX should deliver the goods. My current speakers use the 29RDC at 2kHz LR2 and there is no sign of distortion at 100dB/1m.

I have a couple of the WG148R waveguides too. I find that due to most full size tweeters having slightly dished faceplaces, once you fill the gap with a spacer/gasket, the throat becomes a little too deep for >10kHz to behave properly off axis. I predict about 3-4mm needs to be milled off the rear side of the 'guide, which means you lose the mounting holes.

One thing not to forget with horns/waveguides is that below the frequency range that gets boosted, distortion gets worse. So if you use a waveguide which gives you +6dB from 2-6kHz but +0dB at 1kHz, while distortion is a few dB better from 2-6kHz, distortion at 1kHz becomes 6dB worse than without the waveguide. That makes a practically sized waveguide (shallow, ~6.5" diameter) less useful at making a beast dome tweeter that is already happy to cross at say 1.5kHz, cross any lower.