As I've mentioned in other threads, the Helios design by the late Jeff Bagby (and the not-late Javad Shadzi) is my current project. I am looking for "something reasonable" (put that in a QFD!): relatively high performance, not absurd expenses (~$1k/channel), and something that I can get done relatively quickly. That last one is obvious foreshadowing.
I had contemplated doing my own design for quite a while. I was looking into something that might follow along in the path of the Neo D CC (a relatively compact three way that works as both a Center channel and as a monitor). However, the horrific sound bar that I purchased just after my move to San Diego is not to be tolerated any longer than necessary. So, I started looking at designs. The Dutch & Dutch 8c was very intriguing, but that was obviously proprietary. There were a few other classic designs available, and then I saw the Helios design get mentioned right when the waveguide-loaded tweeter was unexpectedly released into the market (nothing on SBA's "coming soon" page at all!). A quick re-cap of the major design elements:
A few more words of caution: the design was mostly documented on a Facebook group, with a few details that needed to be interpolated. I'll document a few of the steps in this thread, but the reality is that I screwed up the crossover completely, so mark 2 will happen as soon as some additional wood shows up from Northwest Bamboo. But first, let's throw some pictures into the mix to get things rolling.
Oh, yeah, since COVID-19 closed the SDFWA member shop, I built these in my second bathroom using a folding table as a workbench (more foreshadowing). The build uses carbonized vertical bamboo, with a mix of single-ply and three-ply product. The single ply comes from Woodworker's Source (Christmas sale), and the 3-ply comes from NW Bamboo (nice guy; very reasonable prices). Cali Bamboo is headquartered 10 miles from where I live, but they only deliver full sheets. NW Bamboo can breakdown sheets for shipment.
I had contemplated doing my own design for quite a while. I was looking into something that might follow along in the path of the Neo D CC (a relatively compact three way that works as both a Center channel and as a monitor). However, the horrific sound bar that I purchased just after my move to San Diego is not to be tolerated any longer than necessary. So, I started looking at designs. The Dutch & Dutch 8c was very intriguing, but that was obviously proprietary. There were a few other classic designs available, and then I saw the Helios design get mentioned right when the waveguide-loaded tweeter was unexpectedly released into the market (nothing on SBA's "coming soon" page at all!). A quick re-cap of the major design elements:
- Relatively flat in-room performance into the mid-20s
- Relatively low distortion (big caveats on measurement methodology here!)
- Two-way design using a waveguide Beryllium tweeter ($$, ouch!), a big (9.5") woofer, and a "10-inch" (29 cm seems to round to 12" in my math textbook...) passive radiator
- Relatively good sensitivity
- High SPL capability from 100W
A few more words of caution: the design was mostly documented on a Facebook group, with a few details that needed to be interpolated. I'll document a few of the steps in this thread, but the reality is that I screwed up the crossover completely, so mark 2 will happen as soon as some additional wood shows up from Northwest Bamboo. But first, let's throw some pictures into the mix to get things rolling.
Oh, yeah, since COVID-19 closed the SDFWA member shop, I built these in my second bathroom using a folding table as a workbench (more foreshadowing). The build uses carbonized vertical bamboo, with a mix of single-ply and three-ply product. The single ply comes from Woodworker's Source (Christmas sale), and the 3-ply comes from NW Bamboo (nice guy; very reasonable prices). Cali Bamboo is headquartered 10 miles from where I live, but they only deliver full sheets. NW Bamboo can breakdown sheets for shipment.
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