CNC CRP-2448 Auto Gantry Square

I finally got my new CRP-2448 CNC machine up and running. I’ve managed to cut several things quite successfully, none of them Speaker related. But, since I’ve solved a few crucial issues I though I’d share what I’ve learned here. Eventually I’ll set up a CNC blog for these articles but for now they are here.

First, I purchased the proximity sensor kit from cncrouterparts and it works fine. However, I did need to change the auto square code under the “Ref All Home” button. It comes with code to home each axis individually starting with Z, then X then Y then A. I found it works better using the refcombination(x) code rather than the default Z-X-Y-A so I changed the code under the button to:

DoButton( 24 )
DoButton( 22 )
Refcombination(10) Continue reading

SIGGMA AC54W Build from scratch

Greetings fellow speaker builders and web wanderers. This article chronicles my ongoing development as a speaker builder and covers my second high quality speaker project. The AC54W features an Aurum Cantus AC-!30MKII mid woofer and a custom tweeter waveguide. The waveguide enhances the overall quality and power handling by increasing the acoustic output of the tweeter over a very wide range. This waveguide operates from about 13Khz down to 800hz and produces a significant increase in output over most of that range. This allows a crossover slope that reduces the power applied to the driver allowing it to cross much lower at much higher power with much less distortion. More details as we proceed.

The build begins with an enclosure design. At the time I designed this I was limited to a table saw, router and drill press for enclosure construction so the enclosure has no fancy curves. box design
Baffle size ended up 11″Wide by 13″High by 12″Deep rather than the dimensions in the image, ignore the measurement markers on the image above. But the placement is accurate. it’s a simple design with placement dictated mostly by waveguide shape more than anything else. The waveguide dominates the baffle due to it’s enormous size. Continue reading

Demystifying Phase in speaker systems

When I first began fiddling with speakers I felt like I was out sick the day phase was explained. It seemed everybody understood this mysterious effect except me. I understood that filters made phase changes and even that a speaker alone had some phase but exactly what phase is, eluded me. It wasn’t until my ego got in the way that I realized I couldn’t bluff my way past it any more. I had to at least try to understand this mysterious effect called “Phase” if I was going to be able converse with the crowd who did understand it, so I began reading. I was immediately relieved to hear how complex it really is and that I didn’t understand it because it couldn’t be understood. It’s simply too complex. More reading led me to realize the “too complex” attitude was a copout from someone who didn’t really understand phase. So I kept reading. Now I despise articles that present large squiggles of math as “proof” that “a butterworth filter has no phase” and hearing such things only confused me further. Turns out there is more misunderstanding about this innoccuous relationship than fact, even from some reputable places. Many years have passed since I began my search for understanding and in all that time only one thing remains constant. It was so close to me I missed it. In fact I missed it because it is so simple. In reality it’s the phase relationships that are complex, probably the most complex relationship in reality. But in the end it comes to this: phase is a measurement of time. It’s really that simple. It can be expressed in minutes, seconds, hours, years, even centuries, or it can be expressed in degress, radians, milliseconds or microseconds but they all represent the same thing, time. Phase is a measurement of time. More specifically, loudspeaker phase is a measurement of the arrival time of the individual harmonic components of a sound. Continue reading