Pyle PH612 horn + Selenium D220Ti

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
Violet trace = Selenium D220Ti
Black trace = Pyle PDB512
Blue trace = PRV D280Ti

(Fig 1)

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
Red trace = RAW with CDEQ activated
Blue trace = electronic crossover set at 2kHz (24dB/oct) with CDEQ ON

(Fig 2)

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.

full_rs180s_d220ti_ph612_2k_24db_cdeq_crop

(Fig 3)

D220Ti in Inverted Phase

Re-wiring the tweeter in inverted phase did not help (Fig 4).

Now, cancellation if on the left.

full_rs180s_d220ti_ph612_2k_24db_cdeq_rev_crop

(Fig 4)

Adding Delay

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.

full_rs180s_d220ti_ph612_2k_24db_cdeq_rev_ta_crop

(Fig 5)

Time-Aligned Response

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.

full_rs180s_d220ti_ph612_2k_24db_cdeq_ta_crop

(Fig 6)

Sound Quality

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.