|The Pyle PH612 and the Dayton H6512 are clones of the JBL 338800-001 waveguide found in their JRX Series loudspeakers. It was popularized by Zilch in his EconoWave Speaker project in AudioKarma.org.
Measuring about 12″ W x 6.5″ H, it has a coverage of 90°H x 40°V. Stipulated cut-off frequency of 1kHz. Meant for 1″ exit compression drivers with standard 1-3/8″-18 TPI screw mount.
|Matching compression Drivers with the PH612
Fig 1 shows the RAW response of four compression drivers. No crossovers and eq are used.
Red trace = Peavey RX14
|Selenium D220Ti with PH612
It appears the Peavey RX14 and Selenium D220Ti are both suitable. For today, I shall use the D220Ti as this is the compression driver that was first used in the EconoWave.
Fig 2 is the response of the D220Ti with the PH612.
Black trace = RAW
|Summing Dayton RS180S with PH612/D220Ti
Severe interference is observed around the crossover region (Fig 3).
Note the strong cancellation on the right of the crossover frequency.
|D220Ti in Inverted Phase
Re-wiring the tweeter in inverted phase did not help (Fig 4).
Now, cancellation if on the left.
With the tweeter still wired in inverted phase, a delay is added to the RS180S woofer (Fig 5).
With the right amount, a sharp notch is seen at the acoustic crossover frequency.
Fig 6 is the response with the tweeter re-wired back to normal phase.
Now, the drivers are perfectly time aligned. No cancellation to the left and right of the crossover frequency.
Even after time aligning the RS180S with the D220Ti, the summed response is not as flat as I would like it to be. While the summing is correct, there is a broad valley from 2kHz~3kHz. This dip is already visible in the RAW response, so it is not caused by the crossover.
However, on playback, they sounded marvelous. The D220Ti / PH612 combo projected a lifelike listening experience. The mids are crystal clear. Vocals are not recessed nor muffled. And somehow, the RS180S sounded more dynamic in the mid-bass.