Atlas PD4 vs PD5

[djk]

A while back we were discussing this. I contended the PD4 was less efficient and had less high end. Someone else thought otherwise.

Atlas says the -10dB point on the HF is 7Khz vs 10Khz and the difference in SPL is 2.2dB (the chart shows 3dB, but that must be adjusted for the difference in maximum power).

http://www.wvi.com/~vintage/ATLAS2.JPG

After I get my scanner figured out I will post response graphs I made about 20 years ago. They show about:

6dB less output at 4Khz

12dB less at 5Khz

15dB less at 6.3Khz

and a peak at 12.5Khz only 3dB down from the 4Khz level

Both were on the same CD horn (JBL 2370), the 12.5Khz peak would be much worse on any Klipsch midrange horn (due to narrowing HF pattern at HF).

The PD5 was the MR version (two port phase plug, K55V solder terminal type), and shows a very smooth roll-off above 6.3Khz.

[mungkiman]

Thanks!