xt25 in 12in waveguide experiment

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looks like I can crossover xt25 in 12in waveguide at 500hz 🙂
I don't know how loud it can play with such low crossover point,
at low volume tweeter sounds pretty good.
woofer measurements are near field. this woofer will need bass boost.
for now it's baffleless, later I'll probably add baffle.
for amplifier I'm going to use 4 channel t-amp
and equalize woofer with graphic equalizer.
 

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i second jay here, it's not cause it's still playin that it's good, or not distortin. You should add a second pole to your filter, to make a crossover around 1khz, and even then i doubt it will be ideal, but it will be good enough i think
 
I taped gap between tweeter and waveguide with electrical tape, now it's almost seamless. I tried to play tweeters louder, It plays louder than I expected before becoming shouty. it's hard to evaluate tweeter alone. after I add woofer, I'll test them with good amplifier and let you know at what volume sound becomes unpleasant.
unfortunately I don't know how to measure distortion in speaker workshop. I haven't measured TS parameters either(will do it later).
you are all referring to Zaph's xt25 measurement, but he
tested G30 model, I am using G35(with ferrofluid)
 

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Cool idea, Mr. T!

I've been thinking of something similar myself.
Same 12" driver, 4 channel Tripath amp, with a Selenium compression driver on a 12" waveguide. (Why? 'cause I have them).

I agree with the other posters here. You will probably want to mover you x-over point up. You might be hoping to get out of the Peerless 12 as soon as you can, but you really don't have to. Crossing up higher will likely sound better. Or using something else on the WG.

For an idea of what the Peerless SLS 830669 can do, have a look at this thread:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=110583
 
the problem of xt25 is not the motor i think , wich is quite nice, it's the very small radiating area. You should try somethin like one of the seas tweeter or the peerless SLS , or the Dayton RS52 tweeter if you really want to cross that low.

Very good idea appart from that, i wish you the best of luck
 
You need to run some distortion and energy storage measurements too. I did something quite similar with some AirCirc 6600's in a 10" waveguide. The speakers were taken to the RMAF as a prototype, some details here

http://live.audiogon.com/cgi-bin/ces.pl?balancedpowerte&&ManuView&&&&&&&RMF07

Esentially by FR alone, the 6600 could have been taken as low as 500hz. But distortion and burst decay measurements made it clear that something higher than that was ideal, I ended up crossing it around 820hz.

I've also tried many other tweeters in these waveguides, one of which was the XT25 ... and the Scan Ring Radiator too 🙂 Both of those actually perform quite well in the waveguide, they have less gain at 1500hz than the 6600 does, so easier to make a notch for. From my measurements in my waveguide, the XT25 could do about the same as the 6600, around 850hz.

I choose my xover points to try and keep F2 below .5-.6%, and F3 below .1%, just FYI.

And obviously with any tweeter crossing that low, you're going to need a Zobel. No Zobel and crossed that low means severe audible consequences.
 
A quick question.. with a horn / waveguide loaded drivers do you measure the driver-to-driver spacing (thinking about the 1/2 wavelength rule of thumb for wave front integration) from the edge of the horn mouth or is it still from the center of the driver?

It looks like a nice design you have there Turbo. Good to see some slightly different things coming out!
 
thanks for comments everyone. TurboFC3S, those are very nice looking speakers you made.
I'm going to work on crossover later. I just checked how tweeter works in 12in waveguide, I'm impressed how well it sounds off axis. First of all I need to make nice looking baffles (well, maybe not as nice as in TurboFC3S link 🙂 )

I guess these tweeters will be good for low crossover points in waveguides:
http://www.sbacoustics.com/product.php
1.2 and 1.7mm linear xmax :bigeyes:
 
MisterTwister said:
thanks for comments everyone. TurboFC3S, those are very nice looking speakers you made.
I'm going to work on crossover later. I just checked how tweeter works in 12in waveguide, I'm impressed how well it sounds off axis. First of all I need to make nice looking baffles (well, maybe not as nice as in TurboFC3S link 🙂 )

I guess these tweeters will be good for low crossover points in waveguides:
http://www.sbacoustics.com/product.php
1.2 and 1.7mm linear xmax :bigeyes:

Thanks, they did turn out incredibly well ... better than I hoped. The waveguide literally changes everything about how a 1" dome tweeter performs. I think you'll find that it's an addictive sound 🙂

Your response looks a lot easier to work with than the 6600 is in my waveguide ... or than my XT25 is in my guide. I get about 13-14db of gain centered at 1500hz with the 6600, and about 9-10db with the XT25. Especially with the 6600, that makes crossover work quite a test, a notch can only attenuate so much! I did find the magic formula with mine though, and got a nice smooth line from 800hz all the way up, with just a touch of gain again at 15khz.

Have fun playing with it, and keep reporting back!
 
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