Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Multi-Way Conventional loudspeakers with crossovers

Presenting the Trynergy - a full range tractrix synergy.
Presenting the Trynergy - a full range tractrix synergy.
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 3rd September 2014, 09:11 AM   #11
Juhazi is online now Juhazi  Finland
diyAudio Member
 
Juhazi's Avatar
 
Join Date: Mar 2007
Location: Jyväskylä, Finland
xrk971, congrats! This is your best FAST project so far, a real marvel!

Do you hear any resonances in the horn? 3mm plywood for tractrix side panels? Perhaps some PU insulation foam on the backside for damping and a cabinet for the whole thing - presto!
__________________
Radikal aktivist AINOgradient speaker project
  Reply With Quote
Old 3rd September 2014, 09:37 AM   #12
xrk971 is offline xrk971  United States
Got Foam?
diyAudio Member
 
xrk971's Avatar
 
Join Date: Oct 2012
Location: Metro DC area
Presenting the Trynergy - a full range tractrix synergy.
Quote:
Originally Posted by Juhazi View Post
xrk971, congrats! This is your best FAST project so far, a real marvel!

Do you hear any resonances in the horn? 3mm plywood for tractrix side panels? Perhaps some PU insulation foam on the backside for damping and a cabinet for the whole thing - presto!
Juhazi,
Thanks for the kind words! I had bad resonances with one layer of foam core. I was audible and measurable as harmonic distortion. I then used constrained layer damping

Click the image to open in full size.

Here is before and after CLD on the bigger 1.0x scale horn:
http://www.diyaudio.com/forums/full-range/259293-prv-5mr450-ndy-fast-applications-post4036324.html
  Reply With Quote
Old 3rd September 2014, 11:25 AM   #13
xrk971 is offline xrk971  United States
Got Foam?
diyAudio Member
 
xrk971's Avatar
 
Join Date: Oct 2012
Location: Metro DC area
Presenting the Trynergy - a full range tractrix synergy.
Default First Sound!

The sealed rear chambers may just be a simple box, but it took almost as long to cut and assemble as the tractrix horn (lots of cuts whereas the horn was two panels and a top and bottom sheet)! I ended up reducing the volume down to about 9 liters for more bass punch at expense of extension. I checked in the model and a 9 liter rear chamber provides a 97dB at 2.83v and 1m sensitivity and about 103Hz as the -3dB point. The other reason for a smaller chamber was to keep the physical size smaller with the box being 8in x 14 in x 5in tall. I installed grey open cell foam on the inside, added a layer of cardboard on the large top panel to add stiffness as bracing is tough to put here with magnets in the way, I added one cross brace, binding posts, and wired in series on each side. This gives me option of externally wiring for series/parallel for 4 ohms or bi-amp each side at 8ohms (which allows me run the woofers like a DVC subwoofer in pseudo-mono).

Here is the inside of the rear sealed chamber:

Click the image to open in full size.

Here is the speaker during the rear chamber mounting process. I used really long wood screws to go through the main horn flat panel to bite into triple-layer cardboard "nuts" glued into the box corners. This allows the box to be fairly clamped tight yet still removable.

Click the image to open in full size.

Here is a view of the tractrix Synergy sitting on the stool-cum-speaker-stand fitted with a couple of foam blocks to stabilize it. The exposed parts give this speaker a bold chunky look that reminds me of a Transformer robot Kind of cool...

Click the image to open in full size.

Here is a front view of the horn with the bass injection ports visible. The ports are hand cut using a template from the backside, but by the time the razor goes through 3 layers it looks a bit jagged. In any case, the CSA is eyeballed at about equivalent to a 2 in dia round port. Thus I used 5cm dia for the port in the model. In order to measure the volume of the driver chamber, you will never guess how I measured it! Well, since the surround is rubber, the cone and dustcap are polyethylene, all waterproof - I simply poured water into the cone like a bowl and poured the water out and measured the volume with a graduated cylinder It is exactly 185 mL No harm done...

Click the image to open in full size.

Ok, so let's get to the good stuff... measurements. I used the EQ that I previously set for the TC9FD tractrix, but I removed the two rather agressive peak cuts for now. I set the woofer to flat (no EQ) and set the XO's per the simulation: -24dB/oct BW @ 300Hz LPF and 90Hz HPF for the woofers, and -24dB/oct BW @ 350Hz HPF for the TC9FD. I threw in a 0.5ms time delay on the TC9FD (to be tweaked later). Based on the simulation, I also set the TC9FD gain at -6dB to match the lower sensitivity of the four woofers (which is predicted to be 97dB at 2.83v), making the predicted TC9FD sensitivity about 103dB at 2.83v before the cut.

Here is the combined and individual responses of the TC9FD and the four woofers in the tractrix Synergy. As you can see, the XO frequencies worked out perfectly. Akabak is a great help for initial XO setups. There is a well-known room mode dip at 80Hz and 150Hz in my speakerlab. You can see those here, but otherwise, the woofer behaves just as predicted.

Click the image to open in full size.

Here is the harmonic distortion (HD) of the system - below 100Hz, the drivers are exciting panel resonances that are below the bandwidth of the constrained layer damping (CLD) that was used which was very effective for sub 1kHz vibrations. This just means that if one wants to make a clean sounding Synergy for sub 100Hz, it probably needs to be made of something heavier like wood. My goal was to use this down to 100Hz where it will be crossed-over to a bass horn sub, so it has satisfied that goal very well. Above 100Hz, the HD levels are very low - characteristic of a TC9FD, which is already low, and when combined with horn loading for very small excursions, the HD is even lower. This results in a super clean purity of tone. Despite what some may say if harmonic distortion is perceptible or meaningful, in this case, the ultralow HD *IS* perceptible when listening to music. Especially vocals or complex passages with many instruments. The notes are distinct and "clear as bell".

Click the image to open in full size.

The EQ could be cleaned up a bit more to smooth things out, but as is, it gives a pretty decent impulse response as seen here:

Click the image to open in full size.

I also tested out what the woofers could do if I set the XO highpass at 70Hz for a little more extension:

Click the image to open in full size.

Now finally, for the subjective question of how does it sound? Well, drum rol........... In a word, MAGICAL! There is something very special about a single point source covering a 100Hz to 18kHz coming from a tractrix horn that reduces the room wall reflections due to directivity. There is less junk bouncing around the room to mess with your perception, and the sound is *CLEAR* and clean. I have heard this description of the Synergy before: like listening to a big headphone without headphones, but this is in a good way. I can imagine that with two of these in stereo, the imaging and soundstage will be unbelievable. So for only $40, a little sweat, lots of modeling and designing, I am now a Synergy convert and can say without a doubt, this is perhaps the best sounding speaker I have ever built or listened to. Superlatives like best are difficult to use, as there generally will always be something better somewhere. So to caveat this, it will probably lose out to its bigger brother, the 1.0x scale tractrix with the 5MR450NDY, if that were ever "Synergized" with the dual 12in Kappalites for bass drivers.

I haven't had time to do extensive listening, maybe 4 test tracks so far. But each one just blows me away - it's like watching HD TV for the first time. Here is the first sound clip I recorded. One of my favorites to check vocals and articulation. Hope you like it...
Attached Images
File Type: jpg Synergy-0.7x-Build-01.jpg (139.1 KB, 2844 views)
File Type: jpg Synergy-0.7x-Build-02.jpg (116.8 KB, 2847 views)
File Type: jpg Synergy-0.7x-Build-03.jpg (87.0 KB, 3245 views)
File Type: jpg Synergy-0.7x-Build-04.jpg (79.7 KB, 13692 views)
File Type: png synergy-xo.png (100.8 KB, 2757 views)
File Type: png synergy-hd.png (113.1 KB, 3051 views)
File Type: png synergy-ir.png (43.2 KB, 2722 views)
File Type: png synergy-xo-70hz-hpf.png (101.1 KB, 12918 views)
Attached Files
File Type: zip Synergy-0.7x-TC9FD-01.zip (847.9 KB, 138 views)

Last edited by xrk971; 3rd September 2014 at 11:47 AM.
  Reply With Quote
Old 3rd September 2014, 11:40 AM   #14
Legis is offline Legis  Finland
diyAudio Member
 
Legis's Avatar
 
Join Date: Dec 2009
Congratilations X, I'm happy for your success! Those attributes sound very familiar.
  Reply With Quote
Old 3rd September 2014, 11:43 AM   #15
kees52 is offline kees52  Netherlands
diyAudio Member
 
Join Date: May 2009
Location: Sprang-capelle Holland.
Quote:
Originally Posted by xrk971 View Post
Kees,
That is some impressive bass you are getting out of the Phillips and it would appear seamless integration with the Visaton. 120dB+ is very good without hitting xmax.
You should build it based on how good the sim is coming out. My quad 6.5 in woofers can get lower bass but then the box volume has to be very big because they are rather large Vas drivers.
How How, the bass is include tapped horn you did als include.

this is without that horn, my tapped horn I have fold and drawn go to 70 Hz, so it fit well here just for the overlap to bass mid, however efficienty of the tapped horn is not extreme in comparison of your tractrix, and i need analog so I go use a amp for the tapped horn and a stereo amp for tractrix or in my case conic first..

ML-TL picture go to 16 Hz
regards
Attached Images
File Type: jpg ScreenHunter_220 Sep. 03 13.00.jpg (83.6 KB, 308 views)
File Type: jpg infinity1260W-tapped.jpg (386.5 KB, 776 views)
File Type: jpg ML-TL.jpg (290.5 KB, 778 views)

Last edited by kees52; 3rd September 2014 at 11:45 AM.
  Reply With Quote
Old 3rd September 2014, 12:33 PM   #16
xrk971 is offline xrk971  United States
Got Foam?
diyAudio Member
 
xrk971's Avatar
 
Join Date: Oct 2012
Location: Metro DC area
Presenting the Trynergy - a full range tractrix synergy.
Kees,
A well designed TH should get +100dB sensitivity easily. Look for proven designs in the sub forum.
  Reply With Quote
Old 3rd September 2014, 12:48 PM   #17
BYRTT is offline BYRTT  Denmark
diyAudio Member
 
BYRTT's Avatar
 
Join Date: Dec 2009
Presenting the Trynergy - a full range tractrix synergy.
Wow soundclip pretty good "pure - calmness - soft coherent". Could plot of phase turn be interesting.
  Reply With Quote
Old 3rd September 2014, 12:56 PM   #18
Bigun is offline Bigun  Canada
diyAudio Member
 
Bigun's Avatar
 
Join Date: Jan 2009
Location: Waterloo, ON or Herefordshire UK
Presenting the Trynergy - a full range tractrix synergy.
This is an exciting development, I've been a fan of the Synergy 'theory' but it always seemed out of reach to have a DIY version. I hope this thread will take this as far as possible.
__________________
"The test of the machine is the satisfaction it gives you. There isn't any other test. If the machine produces tranquility it's right. If it disturbs you it's wrong until either the machine or your mind is changed." Robert M Pirsig.
  Reply With Quote
Old 3rd September 2014, 01:14 PM   #19
xrk971 is offline xrk971  United States
Got Foam?
diyAudio Member
 
xrk971's Avatar
 
Join Date: Oct 2012
Location: Metro DC area
Presenting the Trynergy - a full range tractrix synergy.
Quote:
Originally Posted by Legis View Post
Congratilations X, I'm happy for your success! Those attributes sound very familiar.
Thanks, Legis. It was your over the top Mega Synergy Study of a Dipole/Cardioid Bass Horn that prompted me to action now to build the stereo pair - but life is also very busy not sure when I will have the mate.
  Reply With Quote
Old 3rd September 2014, 01:15 PM   #20
xrk971 is offline xrk971  United States
Got Foam?
diyAudio Member
 
xrk971's Avatar
 
Join Date: Oct 2012
Location: Metro DC area
Presenting the Trynergy - a full range tractrix synergy.
Quote:
Originally Posted by BYRTT View Post
Wow soundclip pretty good "pure - calmness - soft coherent". Could plot of phase turn be interesting.
You can imagine how much better it sounds in real life. Let me clean up the EQ a bit and then the phase should look much better. Right now there is a lot of wrap due to peaks and dips.
  Reply With Quote

Reply


Presenting the Trynergy - a full range tractrix synergy.Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
full range + woofer OR full range + tweeter ? Bigun Full Range 37 25th July 2017 06:17 AM
why not Tractrix for Synergy/Unity horn ? Bigun Multi-Way 1 6th May 2012 03:28 AM
Korean Sonodyne S-654 Full-Range/Wide-Range Drivers thetubeguy1954 Full Range 6 18th January 2011 10:42 PM
Full size 142Hz round tractrix horns JLH Swap Meet 19 16th May 2010 11:16 PM
DIY 4way full frontloaded Hornsystem with MDF tractrix horns angeloitacare Multi-Way 21 21st February 2010 12:33 PM


New To Site? Need Help?

All times are GMT. The time now is 11:25 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright ©1999-2019 diyAudio
Wiki