Topic: Simple hack to increase SPL on AT853

[mattb]

Hey, I have AT933s too. If I did this mod, would it affect them when I run Phantom? I usually run phantom (I did the SP un-mod to mine) but on occasion a battery box setup would be nice for low profile work.
Another thought is maybe I could build that 4.7k mod into the adapter I built to go from the mini XLRs to the stereo miniplug for battery box use. Would doing this after it goes from three to two wires work?
Thanks for any suggestions!

[whatboutbob]

Anyone *cough* Richard *cough* know how this mod impacts gain compared to the 3-wire config / standard 2 wire?

Off the top of my head I think the 3-wire was about 12dB lower than the standard 2 wire...?

[poorlyconditioned]

Anyone *cough* Richard *cough* know how this mod impacts gain compared to the 3-wire config / standard 2 wire?

Off the top of my head I think the 3-wire was about 12dB lower than the standard 2 wire...?

The "4.7k tweaked" two-wire version should give same loss as 3-wire version, or maybe even a bit *more* loss than the standard two-wire version.

Why more loss???  Well, you're dropping voltage across that 4.7k resistor, and it is not going to your preamp.  Say you've got a 10k resistor in your battery box and a 4.7k resistor inside the mic capsule, then the total load on the mic capsule is approx. 15k (4.7k+10k), but you're only using the 10k part of that, so you're only using 2/3 of the voltage.  The loss is then approx. 20*log10(2/3) ~= -3.5dB.

Maybe Chris can comment.

  Richard

[Javier Cinakowski]

I expereinced some distortion with my mke2's and I would not be suprised if my AT943's will distort in high SPL situations.  They are both 2-wire.

Should I get someone to do the 4.7k mod or should I consider doing the 3-wire set-up?  With the 3-wire I would need a new preamp and I would also need new extention cables for running on a stand. With the 4.7k mod im not sure it would work with the mke2's.  Im kinda bumbed out. I do not know the best route of action here. 

I guess I could just use my mke40's in high SPL situations and use the AT's and mke2's when the SPL's are lower.  Although, I would like to get rid of the SPL variable when chosing what set of mics to run. 


 

[TideBleach]

what would be better for a loud metal show this mod or the 3 wire battery box for SP-AT853's???

thanks

TideBleach

[poorlyconditioned]

what would be better for a loud metal show this mod or the 3 wire battery box for SP-AT853's???

thanks

TideBleach

As far as I can tell, both are pretty much equivalent.  But you will need *some* mod to handle that .

  Richard

[hyperplane]

I expereinced some distortion with my mke2's and I would not be suprised if my AT943's will distort in high SPL situations.  They are both 2-wire.

Should I get someone to do the 4.7k mod or should I consider doing the 3-wire set-up?  With the 3-wire I would need a new preamp and I would also need new extention cables for running on a stand. With the 4.7k mod im not sure it would work with the mke2's.  Im kinda bumbed out. I do not know the best route of action here. 

I guess I could just use my mke40's in high SPL situations and use the AT's and mke2's when the SPL's are lower.  Although, I would like to get rid of the SPL variable when chosing what set of mics to run. 


 

Windorabug: here's what I'm currently doing. I do tape some shows at a local club that are more of the "acoustic" variety, i.e. even though it's coming through a PA, I just can't get great levels running AT mics > 3wire bbox > iriver/Edirol recorder (R-1/R-09).  So, thanks to Richard's aid, I'm building a dual miniXLR > mini-plug cable; thereby running the mics using 2-wire bbox powering. This will, of course, increase the output level of the mics (better levels for softer music, which wouldn't distort anyway).  This way, I can use the *same* pair of mics for louder, or softer shows...  and, it's much cheaper than buying a 3-wire preamp.

To me, the 3-wire "mod" on the mics (with miniXLR connectors) seems to offer the most variety, i.e. with the 4.7k mod, you're stuck with the lower levels and choosing a preamp if you want to use the mics for lower sound (or amplifying the crap out of the WAV file in post). But with the miniXLR connectors for 3-wire powering, you can still "go back" to 2-wire powering as needed, using one of these cables. Yes, the cables cost a little bit (it's the miniXLR connectors that constitute the bulk of the cost)... but like I said, it offers a variety of options and at a more minimal cost than a preamp.

[TideBleach]

what would be better for a loud metal show this mod or the 3 wire battery box for SP-AT853's???

thanks

TideBleach

As far as I can tell, both are pretty much equivalent.  But you will need *some* mod to handle that .

  Richard

thanks 

[TideBleach]

anyone have pics of this mod? also would it be possible to do the mod in a battery box that way you can still use the mics in a normal 2 wire battery box without the dB loss?

TideBleach

[Javier Cinakowski]

also would it be possible to do the mod in a battery box that way you can still use the mics in a normal 2 wire battery box without the dB loss?

I don't think so.  A fellow PT'r had the idea of making an extention cable with the mod.  That way it could be removed.  From what i understand it doesn't work because each mic ground wire is attached to a common point on the mini plug.  I think to get this to work you have to  do it at the mini-plug, in the mic cable or maybe at each capsule?

[TideBleach]

also would it be possible to do the mod in a battery box that way you can still use the mics in a normal 2 wire battery box without the dB loss?

I don't think so.  A fellow PT'r had the idea of making an extention cable with the mod.  That way it could be removed.  From what i understand it doesn't work because each mic ground wire is attached to a common point on the mini plug.  I think to get this to work you have to  do it at the mini-plug, in the mic cable or maybe at each capsule?

thanks. thats what i was afraid of, but at least i dont have to buy a new battery box now just the mics :  )

[poorlyconditioned]

also would it be possible to do the mod in a battery box that way you can still use the mics in a normal 2 wire battery box without the dB loss?

I don't think so.  A fellow PT'r had the idea of making an extention cable with the mod.  That way it could be removed.  From what i understand it doesn't work because each mic ground wire is attached to a common point on the mini plug.  I think to get this to work you have to  do it at the mini-plug, in the mic cable or maybe at each capsule?

thanks. thats what i was afraid of, but at least i dont have to buy a new battery box now just the mics :  )

I believe you *can* implement the 4.7k mod in the mic cable.  For example, if you have a pair of mics each with three wires (2 wires + shield), you could join them together, insert 4.7k resistors between the yellow and the shield on each mic, then run both reds out (left and right mic) to a miniplug.

  Richard

[MLKLuke]

uhm...sorry for the (maybe) stupid question...but...am I High-SPL safe with a 3_wire BBox or I should still need this kind of mod for louder shows (I never had brickwalling problems with denecke PS2 or 3-wire BBbox I'm using with AT853)?

[Chuck]

So Richard:

You replace the 27k resistor (in your famous black board battery box drawing) with the 4.7k resistor?

Chuck

[poorlyconditioned]

So Richard:

You replace the 27k resistor (in your famous black board battery box drawing) with the 4.7k resistor?

Chuck

You have two choices:

- two-wire configuration: replace my (27k) resistor with 4.7k, and use *standard* battery box.  (This has a 10k resistor in series with 9v).

- three-wire: what I drew previously.  That resistor can be anywhere from 5-30k and it will work.  The ideal value is about 10k for AKG CK9x capsules or 22k for AT853 (my previous value was a bit high).  Anyway, I often use 15k so I can use my boxes with both AKG and AT caps.

  Richard