Hi all. Long-time lurker here. This is my first post. I have been diligently going through the multichannel music and speaker review threads, in preparation for getting back into DIY speaker design once I retire and move (not too long a wait, I hope).
I noted the preference many have for mch for music, even upmixed. (Auro 3D seems to have the vote for most effective upmixer.)
I also noted the reduced strength in preference between speaker models in mch compared to mono. That seems to imply that one does not need top-of-the-line speakers for mch. The question arises, what is the minimum requirement for excellent sound in mch?
The relevance to this thread is, what if ASR targeted minimum satisfactory mch as the use case for the community speaker project? In my gedanken experiment, I'm using a Denon X4500H with Auro 3D and Audessey XT32 (with the app). This simplifies crossover requirements to controlling acoustic slope and phase, and possibly driver resonances and impedance; frequency response tailoring can be left to EQ. My thoughts so far:
1) Absolute minimum - Vifa TC9. Will beam in high treble, needs a crossover to the subs around 200 Hz and will still be volume limited. Might work in small rooms with a fixed sweet spot. A foam core cabinet might work here - easy to hang on the walls. I lack the mechanical engineering chops to design a quiet foam core box, though.
1a) TC9 plus Peerless DX20. Crossover could be 1 cap at around 20K; this would improve the highs and correct the beaming, but at the cost of comb filtering. Requires modeling or testing. Still output-level limited.
2) Dayton DSA175. Proven low distortion and benign frequency response per Audio Express Test Bench, better than many ASR recommended speakers if the measurement protocols are comparable. (Note: I am pretty sure the distortion levels are at 94dB, not 104dB as stated in the Test bench article; probably a typo. 104 dB is the level they use for pro drivers and 94 dB for hifi drivers.) If the DSA175 is paired with a Peerless DA25TX00-08, the crossover could be in the range of 1300 Hz LR4, so the directivity should be smooth and wide. No waveguide needed because the DSA175 should not beam significantly at 1300 Hz. Too bad about the overly large faceplate on the DA25, but one cannot have everything. My suspicion is this is close to a minimum setup for high-end mch. A 3-way with a BMR 3" and a small tweeter would also work at the cost of additional crossover complexity (somewhat minimized by doing frequency response corrections in Audessey).
I read somewhere (cannot recall the source) that a desired characteristic for mch music is for the directivity to have a fairly sharp cutoff as one moves out of the listening area. If so, this looks interesting to use with the DSA175. Radian LT3 with waveguide:
https://radianaudio.com/products/lt3-planar-ribbon/?variant=20538618478654
Thoughts?
URLs:
TC9:
https://www.diymobileaudio.com/threads/vifa-tc9-3-midrange-widebander-review-measurements.170856/
https://www.diyaudio.com/forums/full-range/268626-vifa-tc9fd18-08-bang-buck.html
Peerless DX20:
https://hificompass.com/en/speakers/measurements/peerless/peerless-dx20bf00-04
DSA175:
https://audioxpress.com/article/test-bench-dayton-audio-dsa175-designer-series-6-5-woofer
DA25 polars in post #171:
http://www.htguide.com/forum/showthread.php?44456-Ardent-D-aka-Kurosawa-Jr-Winter-Camp/page5