Driver variation between two Tang Band W3-1364S samples

Aim

To compare the frequency response of the pair of TB-W1364S that I presently use for the open baffle OB1 speaker.

Tang Band seemed to have gained a reputation for large variation between drivers (this is based on what I have read on the web). I wished to see how good or bad the matching of my pair were.

Method

Using the offset baffle I decided upon in experiement 1, I measured the on axis frequency response of both samples of the driver at 1m.

Results

Below 2kHz matching is very good at better than 0.5dB difference. For the rest of the range the general trend is very similar but there are also some noticable differences. In particular the 2-3kHz range shows some 2dB of variation. Above 10kHz there are some peaks and troughs with 3dB of variation.

Conclusion

Tonal balance between the two drivers should be very similar, but particularly at high frequency (above 10kHz) the matching of the drivers is quite poor (3dB variation). This is one area where dedicated tweeters, which are not operating in their break-up region would likely fare much better.