What is wrong with miking a bass amp?

[NYMorningstar]

FYI

The shortest "bass" note--A440--has a wavelength of about 2.5 feet. The longest wavelength is 56 feet, and it belongs to 20 Hz.

 

[Toki987]

FYI

The shortest "bass" note--A440--has a wavelength of about 2.5 feet. The longest wavelength is 56 feet, and it belongs to 20 Hz.

Thank you, but I already have that information, and you are correct in your homework. However, I believe you are talking about ONE pure open air complete wave cycle generated by one microsecond pulse of energy at that given frequency which is allowed complete unafflicted development. This is easily explained by a math formula as well. Pity that the formula goes out the window when you stick an sm57 or 58 in front of a transducer that is spitting constant repetitions of any given frequency faster than your calculator can discern. That is why it takes different speakers operating in different frequency ranges to allow relative harmonics to escape the confines of the transducer before getting sort of "run-over" and distorted by other frequencies.
As far as bass goes, you hear stacks of wave pulses at different tonal frequencies quite well before they fully develop the complete wave as they escape the transducer. Your ears and brain understand the pulses and do the math long before the wave completes the cycle if they run in or above the 3db range (which is where you detect a change in amplitude) and if the wave can exibit a sample of its direction (which can be done in a few inches to a few ft). You've already deciphered the first frequency pulse and wait on the next, long before the initial wave has developed.
If I confused you by saying wave instead of wave pulse I sincerely apologize. It is these pulses that are visible. If you don`t have wind to interfere, you can see them using smoke or powder. Sitting at the wheel of a sound reinforcement rig helps fill in the blanks over time....
Are you a salesman?

 

[NYMorningstar]

If I confused you by saying wave instead of wave pulse I sincerely apologize. It is these pulses that are visible. If you don`t have wind to interfere, you can see them using smoke or powder. Sitting at the wheel of a sound reinforcement rig helps fill in the blanks over time....
Are you a salesman?

No need to apologize, you didn't confuse me and I see no need to be blowin smoke. No I'm not a salesman and I'm also not buying what your selling. I'm simply trying to understand miking a bass amp and I don't even see the need for trashing people.
I had a concern that if I miked a bass cabinet about 1' away and there is also a vocal mic in front of it about 7' away, there was a possiblility that it might introduce some phase problems from the bleed. Maybe not canceling out but boosting some frequencies and cutting others. Since you seem to be sitting at the wheel of a sound reinforcement rig why don't you fill in some blanks for me?

 

[Toki987]

No need to apologize, you didn't confuse me and I see no need to be blowin smoke. No I'm not a salesman and I'm also not buying what your selling. I'm simply trying to understand miking a bass amp and I don't even see the need for trashing people.
I had a concern that if I miked a bass cabinet about 1' away and there is also a vocal mic in front of it about 7' away, there was a possiblility that it might introduce some phase problems from the bleed. Maybe not canceling out but boosting some frequencies and cutting others. Since you seem to be sitting at the wheel of a sound reinforcement rig why don't you fill in some blanks for me?

not trying to sell anything or trash anybody. Just trying ease your worries and dispell a concern that you picked up in music store dude. It appears that your worried about something that doesn`t merit a whole heck of a lot of further investigation, if your playing live and the sound is good both room and on tape. You seem to have been well satisfied with the sound you were getting at the time. If you have no feedback loops and there is no phasing distortion of the singers voice due high spl`s onstage flooding his/her mic, and the bass is loud and clear enough offstage, your good to go. And if you have the appropriate mics for the job.
Anytime that you obligate the system with the duty of providing open air reinforcement and at the same time sustain maximum segregation of the independent voices for recording purposes, it can be real task. So real in fact that most every live recording I`ve ever heard, witnessed, or been part of is ultimately labled "live". Why? because it is! The only way to overcome this is with low stage volumes and close mic'ing, using mic`s with close proximity pickup patterns, and possibly "boothing" the instruments.
Removing that ambience element across an open air stage full of mic's ain`t easy.
What cabinet is your bass player using? what is the speaker size? What range tones are dominate? what kind of mic's are you using? Common sense and a little changing in mic placement most often can and will remedy the problem, if there is one.
I`m 49 yrs old, and don`t wheel a rig anymore, although I owned part of two that managed to stay very busy for a number of years. I have run wire and sat the console in front of a few in my time. From Kenny Rodgers, Bobby Goldsboro, Santanna, Mother`s Finest, The Doobies, Hank Jr, and a few more that would make better mention, but I ain`t fishing for attention here.
as I said, im not trying to selling anything , I just gave you an opinion free in hopes it would help, not for you to buy. 'Hope it helped, if not, oh well....
by the way, if the bass player is using less than 15"s, I`d move the mic to about 9" and off axis of the dust cone by about 25 degrees toward the center of the cab.