High-pass filters, low-pass filters - shouldn't they be low-cut and high-cut?
OK quickly now - which band of frequencies does a high-pass filter control?
If you answered correctly within half a second then you have an agile brain indeed. Most of us ordinary folk have to consider carefully before stating that a high-pass filter controls low frequencies.
Yes it does! The more you think about it the more confusing it gets. It's like asking what the right time is when a clock is showing twenty-past but it's forty minutes slow.
A high-pass filter controls low frequencies. High frequencies pass unaltered.
A low-pass filter controls high frequencies. Low frequencies pass unaltered.
Now here is the embarrassing thing. Despite having experience in audio training for almost twenty-four years, we managed to get this wrong in one of our texts.
Specifically we said that a high-pass filter rolls off frequencies above its cut-off frequency. That should of course have been below.
OK, we've eaten Brussels sprouts for a fortnight, and corrected the error.
But we do humbly suggest that it's the terminology that is wrong. We suggest the following...
A low-cut filter controls low frequencies.
A high-cut filter controls high frequencies.
This terminology makes it clear what the filter does that makes a difference, rather than what would happen even if the filter were not inserted into the signal chain.
Now, if only we can get everyone else to agree...