InDIYana 2023 theme initialization....

[Wolf]

If the face of the tweeter is 4.125" diameter or less. Most 32mm domes are not that small.
Wolf

[PWR RYD]

For my design I'm thinking of relatively cheap but well proven drivers with a crap load of crossover parts to make them work

[buggers]

Jon Marsh would approve of that for sure.

[Wolf]

For my design I'm thinking of relatively cheap but well proven drivers with a crap load of crossover parts to make them work

Sounds good to me!
Wolf

[Billet]

For my design I'm thinking of relatively cheap but well proven drivers with a crap load of crossover parts to make them work

That is pretty much the opposite of my typical design

[Billet]

Complex crossovers are a proven technique, however. I have been surprised a few times by the sound of a system with large parts count in the crossover.

[PWR RYD]

That is pretty much the opposite of my typical design

[deschu]

I’m thinking Eton 28SD1 or Dayton RS28F (NLA) with RS270P-04A or Visaton GF 200 or B 200…we shall see.

[Ugg10]

It’s been done before but not seen a fully polished version, so Eminence B102 plus Morel CAT378 would be a nice combination.

[deschu]

I didn’t mean to imply it was full range, just that the whizzer, if over 4.125”, could complicate rule compliance,

[Wolf]

No, that applies fine and dandy.

[deschu]

Speaking of the B102, Frank Bruno aka HamHeadBass in NY is closing up shop and selling off the inventory of his custom version thereof, aka the FB-10, which he claims has extended highs and lows, although his fs and sensitivity are higher. $80 versus $130 for the B102 at P-E. I have no idea how glorious the 2nd order harmonic distortion will be though.

[deschu]

The Kartesian TWT30 is also an interesting option… they also provide a simple horn for it, that while 110mm is diameter, it could be easily imitated with a smaller/rules-compliant flange diameter.

[jhollander]

So OK to use a tweeter that fits in a 4 inch square or can we use the area equal to 4.125 diameter circle for the rectangular area? Just thinking about some ribbons.

[Wolf]

I am fine with either 4-in square or 4 1/8 diameter that is fine.
Wolf

[jhollander]

So the Dayton DC28F is 4.33 inches in diameter does Not qualify, but the truncated DC28FT would qualify by area?

[Wolf]

I never said anything about area. 4.125" diameter or smaller, or 4" x 4" square or smaller. This means the trunky-Silkie is too big in both measures.

[KEtheredge87]

Man... I need to seriously consider how I want to approach this. I have a pair of Satori WO24P-4s that need a use, so I could go high end tweeter. I also don't know what I cna get away with by really pushing a tweeter too dang low for the fun of it, so I wouldn't want to super abuse a bunch of higher cost parts too... How should I consider a tweeter for this? Just distortion plots, lower Fs is best, something else?

[jhollander]

Divide and conquer, 3-4 tweeters should do it.

[KEtheredge87]

Hah. My first TTTW design

[deschu]

Man... I need to seriously consider how I want to approach this. I have a pair of Satori WO24P-4s that need a use, so I could go high end tweeter. I also don't know what I can get away with by really pushing a tweeter too dang low for the fun of it, so I wouldn't want to super abuse a bunch of higher cost parts too... How should I consider a tweeter for this? Just distortion plots, lower Fs is best, something else?

My approach, flawed as it likely is, has been to look for faceplate-compliant tweeters with larger diameters that have low Fs and large Xmax, and then also trying to find reviews, distortion, and csd data when available on the 'net before ordering some. I believe that Xmax (linear) and (physical limit) is likely to be the predominant thresholds of stuff starting to sound bad and approaching tweeter damage, respectively, as the crossover frequency is dropped and the SPL is increased.

A coworker of mine, who has had a long history in hifi, has been a recent fan of crossing over lower than recommended, but he compensates heavily in these designs by not driving them loud, and he generally tries to stay at least a bit above Fs. My interpretation of the competition, however, is that the ability to provide a non-quiet SPL will be judged favorably.

My current mix of trial tweeter are: Eton 28SD1, Kartesian TWT30, BlieSMa T34A-4, and the CSS LD22F (which I believe is a wavecore + faceplate)...there's some serious money in some of those tweeters if bought new, but eBay came to the rescue. Woofer-side: Visaton GF200, Peerless 830869, Dayton RS270P4A, a variant of the Eminence B102, and the Silver Flute w20rc38-04. My intent is to measure the tweeters for distortion and then Xmaxes (via ARTA with Baumer laser sensor).

I'm presently interpreting the faceplate rule as the tweeter's nominal/original manufacturer faceplate need to meet the dimensions (regardless if modified for the entry), but that a waveguide needs to only meet the faceplate requirement in it's final form. That is, that I can duplicate or modify the optional Kartesian TWT30 waveguide (TWT30_Horn) (which is non-compliant due to it's mounting pattern but not the guide surfaces) so long as the final entry meets the dimensional requirement....but I think this is probably at the edge of the rules.

[rpb]

I've crossed the RS270p at 2.5k to a Peerless H26 tweeter. Crossing lower with a std dome should be easy,

[deschu]

The H26TG meets the contest requirements as is....are you trying to tell Wolf to make it more challenging?

[Wolf]

H26 applies, no question.

I don't want to either choke or flood the motor. You have to have a design flow or stifle creativity. Necessity breeds invention.

[rpb]

I was just showing that you don't necessarily need a tweeter that can be crossed at 1.5k. It could be that a lower xo would sound better. That's all. The x-over is not a simple one on this (my) speaker, and this was not a totally finished design. I only have one RS270p woofer currently, Got lucky on the off axis I suppose. I have some Morel. and CSS tweeters I could try, but my future plan may be a 3-way with this woofer.

[DrewsBrews]

"stand mounts preferred but not required"

As in tophats for tripods?

[Wolf]

No, as in bookshelf style. Not many of us use poles like PA.
Wolf