[nightanole]

Should i even worry about them?

Low-Pass Filters

High-Pass Filters

Input Capacitors for Headphone Amps



Most of the time here we use input/output cap values that have cut off frequencies well above or below the human hearing range (2hz and 100khz for example) to reduce phase errors. But what do you do when you want to filter out line level frequencies that are in the audio spectrum such as a high pass for a book shelf speaker or some headphones that dont like bass?

If i want to filter out stuff below 100hz, its going to be out of phase 45degrees at 100hz and still be changing phase till it hits 1khz.

With 2nd order speakers its easy to overcome the 180shift, you just flip the tweeter, but what do you do if you just want to filter out the bass or roll off the highs sooner? Do you just not worry about the phase since it is affecting all speakers at the same time and your not recording? No one complains about an inverting amplifier as long as all channels are inverting. But what about phase inversions due to frequency?

 

[kevin gilmore]

With respect to speakers, it is a very big problem. There are lots of interesting
ways around this to deliver both accurate phase and frequency.

Look up USA patent number 4,771,466
By Richard Modafferi as a great example.

Also known as cauer filters which are only practical when done as
active filters before the power amplifiers.

These days its even easier to do everything with massive amounts of
DSP and then stacks of power amps, one for each transducer.