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In the Forum: Horn-Loaded Speakers
In the Thread: Deep End DIY - Australian take one Macondo.
Post Subject: The half-stackPosted by anthony on: 10/1/2017
I have finally put together a half-stack of my Bass Cannons concept.

Half Stack Side.jpg

Half Stack Front.jpg

The four Cannons wired in parallel and stuffed according to my previous trials on a single tube end up with Fs=41.7Hz and an impedance response as shown below...

Half Stack.jpg

...which means that when 8 Cannons are in the stack the impedance will vary from 0.85R to 2.9R at resonance which nicely suits the Bass OPT that I have here.  To test the half-stack I soldered in the Bass OPT to the prototype Melquiades circuits and took some measurements and did some listening.  The SPL response is quite linear which is good and the cabinets behaved themselves when I played sines between 10Hz and 100Hz...not many vibrations and steel ringing very well under control.  In comparison to the small 2 way standmounts I have here the sines were easy and uncompressed and undistorted to listen to, a really huge difference in tone and yes, I was pushing the two way harder than it would like, but the volumes were similar.

Although not really fair, that little test has driven home to me just what these Cannons can bring to my audio.  Only fools listen to sine waves but in this instance it was very instructive and helped me out in a "you've made all this effort but does it actually do what id needs to do?" kind of way.  Yes, they work, and they are a quantum leap forward from those little standmounts.

Here is the prototype Melquiades and the big bass OPT pushing sub 2R into the half-stack...

Ah valves.jpg 

So, at this stage it looks like the Bass Cannons project is a "go" to finish.  They actually look pretty good in the room, and you can see that I have begun by time aligning them for a 2.35m listening distance. 

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