AFMG Network Forum

ernald · Member

Hey, well Im kinda new to this program, so hope this doesnt sound too ridiculous.
Well anyways, I chose a loudspeaker and set it as a female voice. When I viewed the 3dB cones, I saw that they were behind the speaker. How come this is so? Shouldnt they be towards the front??

Also, well Im trying to use a speaker to simulate a number of different musical instruments. I know for sure that I will put the speaker to have a flat frequency response to represent a variety of musical instruments. But what other parameters should I take into consideration of this? Any speakers in particular I should use?

Thanks for the help.

Jim Mobley · Member

Hi Laughter, welcome!

You are presumably looking at the 3-D Coverage Cones at the default frequency of 1 kHz. At this frequency, the female source has a dispersion of about 250 degrees to the -3 dB points, so in the model this will appear to be behind the source. (Remember, the -3 dB is referenced to the on-axis SPL.)

This makes sense when you consider that the wavelength at 1 kHz is longer than the width of a human head. If you look at higher frequencies, you'll see the dispersion tighten up.

As for simulating instruments, as a general rule, use a loudspeaker of similar size to the instrument, but remember, most pro-audio loudspeakers are intentionally more directional than most instruments--particularly at the high frequencies.

ernald · Member

hey with respect to that whole thing about modelling musical instruments as a speaker. Well I think I'll make a new speaker and leave the directivity constant at zero. Also the polar plot will have a uniform response, hence sound is at all directions. I think that any musical instrument would be able to fall within this speaker. What do you think? Im also going to drive the speaker such that it has a flat freq response.