Topic: AKG 391 Phantom Powering Question

[nickgregory]

OK, so I have powered my mics since I have had them from the MP-2 at the 15V setting, since the spec sheet shows that the mics can accept 9-52V of power.  Realizing that the spec sheet said this, I assumed that if I ran at the 48V option avail on the MP-2, I would just be wasting battery power.  Now onto my question...

So in testing the cables that Daryan made for me (which are great...everything works great!), I switched to 48V just for the hell of it...when I did, everything remaining the same, the mic input to the MP-2 jumped...i.e. I was getting a hotter signal.  I went back and forth a couple of times to confirm this, and every time I went from 15 to 48 the signal got hotter.  My question is with this being the case, am I losing any of the "range" of the mic by running it at 15V?  I believe that the hotter signal is just a result of the more power juicing the mic, but I don't know if this translates into a more "detailed range" so to speak...

Any opinions?

Thx in advance.

Nick

[nickgregory]

^BUMP^ Any opinions???

[jlykos]

I don't know.  Try running at 15 for one set and 48 for another and listen for any differences.  I don't think that there will be any, but that is a hypothesis, not an answer.

[nickgregory]

that is definitely my plan Jamie...thanks!  Kind of hoping that Mr. Nutter or Mr Lucks will respond here if they have any experience as well...!

[danmorgan]

that is definitely my plan Jamie...thanks!  Kind of hoping that Mr. Nutter or Mr Lucks will respond here if they have any experience as well...!

Nick,

you might wanna check over at Oade as well.  I'm sure Doug would be able to help you out as well.

[Lee]

if I'm not mistaken, you're giving up a little clarity in the low end as well as some SPL-handling capacity by running at a lower phantom voltage... I could be wrong though.

[nickgregory]

thanks guys...I will post over at Oade as well...and run some tests...I will let you know what I find

[sexymexi]

it shouldn't matter..  i've read up on 391s and they are unlike many mics. cause they can work at 9-48v without sacrificing any of their capabilities. i don't know the site that i read this on, i can't find it but i am 100% positive i read this,  so i'd run lowest power and save batts... good luck..

[nickgregory]

it shouldn't matter..  i've read up on 391s and they are unlike many mics. cause they can work at 9-48v without sacrificing any of their capabilities. i don't know the site that i read this on, i can't find it but i am 100% positive i read this,  so i'd run lowest power and save batts... good luck..

I agree, and understand that this is the "party line" that AKG gives...since they told me before to   ...but the hotter levels have a reason...just gotta figure out what the reason it  

[sexymexi]

yea.  i don't know why they would run hotter at a higher phantom power range. but... your guess is probably better than mine, its your rig you know more about it than i do.  i still don't see how more power would make them run a higher signal, cause they should have a regulated power out, i don't remember the output signal, but i'd think it wouldn't matter reguardless the power as long as it was enough to power the mic.

[nickgregory]

OK, I have run the 391s at the 48v setting for a couple of shows, and while it bears more testing, I "think" I am hearing alot clearer highs, and a more defined low end.  I am going to try this a couple of more times and see if I still feel the same way, but my gut tells me that for whatever reason, feeding these more power is giving me a more defined sound at the two extremes.....

More feedback as testing continues...

[BCostigan]

Everything I've read on mics and phantom power usually says 'more is better'.  That meaning if the mics will take 9-52v and you can provide 15 or 48v give them the full 48.  My assumption is that the signal is more easily passed at 48 volts. The 9 volts represents the bare minimum to pass the signal.


I could, as always, be wrong.


Actually, I used to run the same setup (393s->mp2) and always ran them at 15v saving the batterys.  The level indicaters would never light up more than the first 3 with good levels on my deck.

This summer at IT cpclark was running AT 4041s (?) at IT to an mp2 and almost all the lights on the mp2 were lighting up....I thought maybe his mics just ran REALLY HOT but maybe it was because he was using 48v?


Interesting observation/question though!

[wbrisette]

I ran these with the B-18 battery modules for a while. Then switched over to the Wendt X2 after about a year. There was a change in the sound, but that was due to the preamp changing and not the bias voltage applied to the microphones. AKG claims, and why should we doubt them, that there isn't any sonic difference between supplying the mics with 9v and supplying them with 48v. In either case the microphone is suppose to give you the same output sound-wise.


Wayne

[nickgregory]

I ran these with the B-18 battery modules for a while. Then switched over to the Wendt X2 after about a year. There was a change in the sound, but that was due to the preamp changing and not the bias voltage applied to the microphones. AKG claims, and why should we doubt them, that there isn't any sonic difference between supplying the mics with 9v and supplying them with 48v. In either case the microphone is suppose to give you the same output sound-wise.


Wayne

definitely understand their claims.....but I am not sure if I buy it....I am going to run a couple more test cases over the coming weeks...and I will post some samples for everyone to tell me what they think!

[F.O.Bean]

more is better.....i bet ya get a more "clarified" signal from the 48v...i could be wrong tho.....