You are probably talking about a type of microphone used to pick up those large bass frequencies coming from the bass drum.
Microphones and speakers work in a very similar way, they operate by using an electric signal to transmit/receive audio messages. In fact, you can rewire a speaker to work as a microphone! Typically, the larger the speaker, the lower the frequencies that it can pick up. Since a 10-12" speaker is a very large diaphragm, it will respond very well to frequencies well below 250 Hz
These speakers used as microphones are placed inside a resonator drum placed in front of the port hole of the kick drum. The resonator drum enhances the presence of the low end frequencies and as a result, you have a very punchy, powerful, and deep kick drum sound with a lot of presence.
I am not quite sure what you mean by "Bass drum cover"But I have a feeling you mean the front head called the Resonant Head of the bass drum.A hole allows for a mic to be placed somewhat inside the drum to capture the whole sound of the drum.
It allows for greater projection of sound and alters the tone of the drum. It is also used for recording or when micing a drum for live performance: it is easier for a microphone to capture the sound of the drum when it is inside or directly in front of the hole. http://www.wikihow.com/Port-a-Hole-in-a-Bass-Drum
The hole in the shell is generally termed the air vent.
When you hit the top of the drum (also known as the head), the sound vibrates down through the drum and out through the hollow hole at the bottom. This is why professional drummers hold the drum between there knees so that the sound is clear and doesn't drown out.
If you mean the hole cut into the skin, it is called the port hole and it is used to mic the bass drum. If you mean the groove cut into the inside diameter of the hoop, it is used for attaching the kick pedal.
I am not quite sure what you mean by "Bass drum cover"But I have a feeling you mean the front head called the Resonant Head of the bass drum.A hole allows for a mic to be placed somewhat inside the drum to capture the whole sound of the drum.
It allows for greater projection of sound and alters the tone of the drum. It is also used for recording or when micing a drum for live performance: it is easier for a microphone to capture the sound of the drum when it is inside or directly in front of the hole. http://www.wikihow.com/Port-a-Hole-in-a-Bass-Drum
pull wheel off and then look for a slot in the brake drum on the front of it and rotate drum until you see the gear through the hole in the drum, turn the gear to set up the brakes.
A drum with a hole in it
the 406 hand brake has a separate drum and shoes which is part of the disc assembly and adjusted via a hole in the front of the drum
You blow into the mic and the mic is the little hole on the front of the DS.
Remove one of the heads with a drum key.
The hole in the shell is generally termed the air vent.
it had a stick and a hole
Optical drives have a little hole in the front. Typically a paper clip is un bent and stuck in this hole to manually open the drive.
It is where the tow hook threads in.
A hole.