The design looks excellent. The crossover at 2 KHz means the mid range will be excellent and the off on and off axis response looks excellent because of this.
Not sure why they inverted the polarity in the ULF. I find this can create a disconnect between bass and mid range (our hearing is phase sensitive especially to 180 degrees changes in those lower frequencies as any one with a subwoofer can attest to and why all subwoofers have a polarity switch - there are also science papers proving this).
Looks like the transmission line bass has the Achilles heal of most TL designs - it is letting far too much higher frequencies get out - this will reduce mid range clarity.
https://www.stereophile.com/content/egglestonworks-viginti-loudspeaker-measurements
I agree with the philosophy - a large 12 or 15” woofer is only useable to a max of 500Hz. JBL large woofers (with the folded cones) go to 700 or 900 but they would break up in a controlled manner. I like Eggleston’s crossover points - they are close to where physics says they should be for optimal driver performance.
Not sure why they inverted the polarity in the ULF. I find this can create a disconnect between bass and mid range (our hearing is phase sensitive especially to 180 degrees changes in those lower frequencies as any one with a subwoofer can attest to and why all subwoofers have a polarity switch - there are also science papers proving this).
Looks like the transmission line bass has the Achilles heal of most TL designs - it is letting far too much higher frequencies get out - this will reduce mid range clarity.
https://www.stereophile.com/content/egglestonworks-viginti-loudspeaker-measurements
I agree with the philosophy - a large 12 or 15” woofer is only useable to a max of 500Hz. JBL large woofers (with the folded cones) go to 700 or 900 but they would break up in a controlled manner. I like Eggleston’s crossover points - they are close to where physics says they should be for optimal driver performance.