Synergy horn build

[jhollander]

The top and bottom panels are rectangles that only have 30 degree angle cuts along the long sides. Those cuts can be made on the table saw. The top and bottom panels tie directly into the sides of the cabinet. The only compound cuts are on the inside panels.

The process in the write up drawing is to cut the interior side panels by starting with 45 degree cuts, then to cut out the triangle shape with the first jig. The first jig get the interior side panel shape right but the part needs another angle cut with the second jig to get it to lay correctly on the top and bottom panels.

As I made a lot of mistakes, I went to the scrap bin and pulled out a couple of pieces to show the difference between the first cut then the angle relief cut.

It's a cool result that the relief angle cut ends up making a perpendicular line in the 45 degree cut side.

[shrub0]

John, i see in your write up a jig to make the side panels of the horn, but what about the top and bottom sections of the horn? I am also confused on what you mean by relief cutting. Thanks.

[jhollander]

I did not get a voltage measurement. The mic was about 12 inches and adjusted just below the clipping at 115 dB. I've had them near 105 dB at 1 meter briefly looking for port noise. The DCS165's are pretty robust. The box model says about 108 dB before x-max without using any safety factors. Again this is not a high SPL design.

The off axis measurements are horizontal 0 to 90, mirrored. I haven't planned on looking at vertical until after April when I start a simple synergy project.

[shrub0]

Looks great John! Any idea of the drive level or SPL during the distortion test and do the woofers fall apart in the 20-70hz range? Are the off-axis measurements all horizontal?

[jhollander]

Distortion, 2nd 3rd and 2nd through 5th, 2nd through 5th

[jhollander]

off axis measurements

[jhollander]

John, any chance you can do harmonic distortion or polar graphs for your synergy horns?

It's on my list, probably some time in December.

[shrub0]

John, any chance you can do harmonic distortion or polar graphs for your synergy horns?

[300Z]

If I had the room I would run those BMS coaxials. But for the meantime I gotta stay with something more like bookshelf monitor sized.

[Wolf]

I've not heard any BMS, but the coaxials have always interested me.
Wolf

[300Z]

WRT CDs, I have a tremendous respect for Radian drivers. They sound VERY good.

Wolf

In the future I may do another build and Radian is on my short list of CD to use, it's either Radian or BMS.

[Wolf]

WRT CDs, I have a tremendous respect for Radian drivers. They sound VERY good.

Wolf

[300Z]

Actual listening to compression drivers and other tweeters. Granted I've not heard a bunch of Cds but of those I've heard, none have the sounds of bells, brass horns, and triangles that I associate with better sounding tweeters. That's my opinion, of course you can form your own.

I was hoping you had done more objective testing.
I moved to CD back in 2008 with the B&C DE10 that Zaph tested and then to a JBL 2408H mated to the JBL 6x6 PT waveguide in 2010 and in my application it has worked very well, before this I had been using the Dayton RS28A and Seas 27TDFC.

[jhollander]

I've heard some pro implementations but typically discount those as designed for economy. My experience is from taking Selenium, JBL, and Eminence CDs in a SEOS WG and trying to make them sound as good as the dome and ribbon drivers I have.

This was my test bed

[spasticteapot]

Maybe it's because of how they were implemented, CDs usually being used for hi efficiency pro audio rather than Hi Fi systems..

IIRC, pro sound gear tends to achieve CD horns through diffraction. Compact and efficient, but not exactly hi-fi.