Pioneer BS22 Grill Mod: Before and after measurements
The Pioneer BS22's have been one of the most recommended and highly reviewed entry level or budget speakers in recent memory. While very good at the price point they are not perfect.
One known issue is how very non-transparent the grills are. I've read some second hand accounts that Andrew Jones designed the speaker with these grills in mind, or at least to be used specifically with the grills on. But after the measurements, I can't see that as anything but marketing hype, the all to common, "it's a feature" excuses.
That all being said, I find the Pioneers to be a bit muted and subdued as is, and always listen with the grills off. So, I decided to see if the grills or more specifically all the plastic in front of the tweeter could be modified and help correct this "feature". These are my results.
In the above graphs you have close mic measurements on top (mic at tweeter) and then 1 meter measurements at below. 1/6 octave smoothing used on both.
As you can see, with the grills on there is a pretty large dip at centered at 8.5khz. (in RED), removing the plastic (in GREEN) didn't have all the effect that I had hoped for, but there was some measurable improvement. How well that translates to your ears, I'm not sure. Removing the grills entirely (in BLUE) is still the best option for the flattest frequency response from the tweeter.
Does modding the grill make a huge difference? No, not really. But if you prefer the look of the grills being on or you are trying to protect the tweeter from little fingers; I do think it is a worthy and easy mod to make.
Below you can see how much was cut out of the grill. Nothing too extreme and there is still plenty of strength to the grill.