Small Syns

A bunch of years ago I used Liquid Nails to mount a big sheet of HDF to a basement concrete wall for my wife and kids to kick against for their karate practice. It fell off in about a year (after very little kicking, in fact, karate go a lot less interesting soon after I mounted it). The adhesive stayed on the wall (not fun to get it off), but left hardly a mark on the hdf.
 
I don't know where you are in terms of wood cutting and glue, but some things a i learned along the way--

Glue to use: Titebond I. With lots of clamps, preferably. Clean up squeeze out with a damp cloth.

To keep glue from bonding to clamps and surfaces, use wax paper between. Particulay when laminating the baffle, clamp against a back panel piece
 

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No news on that, but there isn't any need for it on this particular design because the original DFM-2535R00-08 isn't being discontinued after all due to popular demand! Still available at Parts Express, and still remarkably inexpensive (particularly considering all the very expensive compression drivers that it pretty significantly trounces for home use).
 
Bill, I've certainly been inspired by this design, xrk971s, and the synergy designs. Your spreadsheet is great. I've spend a ton of time with HR, and it looks like I'm on to 3-way with a non-cd tweeter, single mid, and two woofers (still trying to crack the 2-way nut)

Thank you!
 
Thanks jrh, glad you find some of this stuff useful.

I've never gotten a Synergy to go right in less than a 3-way system either. Cask05 seems to do pretty well with his as a 2-way (using a 2" cd and a huge horn so he can merge them at a lower frequency). As do xrk and Bushmeister.

I've always tended toward the smaller exit drivers (so far), which kind of leaves me in 3-way or even 4-way territory. If you get all the drivers within a quarter wavelength at their crossover points and don't mind doing more 'ways' in the crossover, I don't think it really matters. The coherence of a well-arranged Synergy/Unity horn is always going to end up sounding like a 1-way in the end.
 
Hi Bill,

I had to put the project on pause for a few months due to moving, however I did just give my brother my old Klipsch towers to incentivize completing this project! The waveguides are done, I just need to get the boxes put together and build the crossover.

Looking forward to getting back into it after the new year.
 
Thanks jrh, glad you find some of this stuff useful.

I've never gotten a Synergy to go right in less than a 3-way system either. Cask05 seems to do pretty well with his as a 2-way (using a 2" cd and a huge horn so he can merge them at a lower frequency). As do xrk and Bushmeister.

I've always tended toward the smaller exit drivers (so far), which kind of leaves me in 3-way or even 4-way territory. If you get all the drivers within a quarter wavelength at their crossover points and don't mind doing more 'ways' in the crossover, I don't think it really matters. The coherence of a well-arranged Synergy/Unity horn is always going to end up sounding like a 1-way in the end.

I have to agree with this one. I took one of my SB Acoustics SB65s, and mounted it to one of my 18Sound horns. And though the frequency response and distortion performance was quite good, the highs didn't seem as "clean" as a good dome tweeter or compression driver. And I REALLY like to listen loud, and the SB65 sounded 'strained' compared to a two-way.

An externally hosted image should be here but it was not working when we last tested it.

CV8HiY0.png


Here's the measurement, if anyone's curious, from my thread here : Horn Loaded Computer Speakers (HLCS) - Car Audio | DiyMobileAudio.com | Car Stereo Forum
 
I have to agree with this one. I took one of my SB Acoustics SB65s, and mounted it to one of my 18Sound horns. And though the frequency response and distortion performance was quite good, the highs didn't seem as "clean" as a good dome tweeter or compression driver. And I REALLY like to listen loud, and the SB65 sounded 'strained' compared to a two-way.

An externally hosted image should be here but it was not working when we last tested it.

CV8HiY0.png


Here's the measurement, if anyone's curious, from my thread here : Horn Loaded Computer Speakers (HLCS) - Car Audio | DiyMobileAudio.com | Car Stereo Forum
Which model is the 18sound horn? It looked like the XT1464 that Bushmeister used in his bookshelf synergy, and that measured really really good, after fixing the notches from the driver horn interface.

Sent from my X9009 using Tapatalk
 
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I have to agree with this one. I took one of my SB Acoustics SB65s, and mounted it to one of my 18Sound horns. And though the frequency response and distortion performance was quite good, the highs didn't seem as "clean" as a good dome tweeter or compression driver. And I REALLY like to listen loud, and the SB65 sounded 'strained' compared to a two-way.

Img_0834.jpg

CV8HiY0.png


Here's the measurement, if anyone's curious, from my thread here : Horn Loaded Computer Speakers (HLCS) - Car Audio | DiyMobileAudio.com | Car Stereo Forum

It's good that you tried it but if you read the xBush thread, it takes a bit of work to make it sound excellent. Need a transition throat adapter. It plays quite loud with low measured HD so not sure how you are playing it that it feels strained. The driver has nice highs.

Adapter I used:
526771d1453502400-bookshelf-multi-way-point-source-horn-xbush-throat-adapter-v3-wireframe.png


Adapter Bushmeister used:
536563d1457612485-bookshelf-multi-way-point-source-horn-sb65-mounting.jpg


Look at the before and after throat mods. Here is after;
525315d1452897769-bookshelf-multi-way-point-source-horn-distortion.jpg


Best part is smooth directivity:
536587d1457613073-bookshelf-multi-way-point-source-horn-polar.jpg


Anyhow, don't discount it based on quick and dirty test without use of recommended adapter.
 
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I'm not saying the SB65 is unlistenable on a horn; in fact I can't think of any driver that can work as well as it can work from 500hz to 20,000Hz that costs less than $1000. It's THAT good! The only driver that can soundly exceed it, with that kind of bandwidth, is a TAD 2001.

But the upper treble still sounds a little 'off' and the power handling isn't as much as I'd like. (I like to listen REALLY loud; I got accustomed to using a 15" 1000 watt B&C as a midrange.)

If you don't like to listen at deafening levels, the SB65 is pretty darn special.
 
I edited the first post of this thread to include links to the build drawings of both the sealed and shelf ported versions of the SmallSyns and measurements with the finalized crossover.

Because that info is spread throughout this thread and tedious to dig out otherwise!

Any builders of this design (or derived from it) out there, I'd love to hear from you.

-Bill

Happy New Year, Bill.
Once again, I really appreciate your work.
I'm building SmallSyns project and have a question: If I change two 6.5" B&C woofers that you use, for one B&C 10NW64 8ohm (that I already have) what do I have to change in xover?
Thank you.
Serg.
 
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Hi grec13,

Well, if you used that, you of course won't have the same design (much at all, really). The horizontal directivity control to a lower frequency (via array effect) will be gone, and much of the mid-to-woofer array crossover tuning will be to no real point. Also, the vertical pattern will have a notch in it's off-axis response (because the larger cone center can't get close enough to the center of the waveguide, nor be practically placed behind part of the waveguide).

But otherwise, the general idealized rule for changing a 4ohm crossover for on 8 ohm driver is that you double all inductor and resistor values and divide all capacitances by half. That of course ignores differences in driver responses and resonances, so if you go that route I'd recommend getting a measurement microphone and adjust things after you get it built for at least a good on-axis response.

(btw, the woofers I used aren't B&C, they're FaitalPro)
 
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