Resistor value shoot out

[ParsonsMatt]

Alright, here it is... After a good bit of soldering and recording, I've got a shoot out for you to enjoy. This is part II in my "Resistor Cable" experiment. After doing some more calculations, I realized that the resistors I got for the first run of cables were not optimal, and that the cables were still bringing the impedance a little too high for the rating. So I got more resistors, this time with a more appropriate value, and got the impedance down to exactly where it needs to be.

There are two sections. Voice is just me talking, doing harsh vocals, and then jangling keys. Guitar is a quick clip, single tracked L/R, with the SM57 .5" off center of the cone. I know the tone isn't that great. A, B, and C represent different tests. One of them is no resistor cable at all ( all natural! ), one is with an 800 ohm resistor, and the other with a 400 ohm resistor.

The clips are here:

http://www.soundclick.com/bands/default.cfm?bandID=442291

 

[TheWinterSnow]

I am not hearing too much of difference. Looking into the physics of sound and impedences, resistance will bring down the volume slighly and roll off the high end slightly, the amount required to take a failry noticable amount of highs would be a value that is so high that the signal comming thoruhg would be pretty weak and failry unuseable considering the level matching would result in a higher noise floor.

imo taking all that time and money to build cables to match impedences wouldn't be worth it, still doens't mean it could be useful.

 

[ParsonsMatt]

It's a 1-2 minute soldering job and resistors cost about .10 cents... So it's not a huge investment on my part. Here's a link to an article that describes what I've made: http://www.recordingmag.com/resources/resourceDetail/330.html

For whatever reason, these clips all sound identical despite the different resistor values. The last test I did, there was a pretty noticeable difference. So I really need to do some more testing to see if it actually does anything.

What do you think of the tone itself?

 

[AudioGeekZine]

this is used to LOWER the impedance of the mic and reducing the load on the preamp, giving you more gain with lower noise and more high end. At the sacrifice of possibly damage from phantom power.

 

[Omega_Void]

At the sacrifice of possibly damage from phantom power.

The preamp will see less impedance upstream, so more phantom power would be drawn, but the extra current will be drawn by the gizmo resistor. The impedance of the voice coil in the mic remains the same so current flow in the mic will not increase.

 

[AudioGeekZine]

in theory
I've also seen people like Shure's engineers hypothesize that the constant voltage being sent to the diaphragm will push it out, much like a speaker with a constant dc voltage.

 

[Omega_Void]

I've also seen people like Shure's engineers hypothesize that the constant voltage being sent to the diaphragm will push it out, much like a speaker with a constant dc voltage.

Phantom power puts no voltage across the voice-coil anyway - both ends of the voice-coil are elevated to 48V above the phantom power circuit's ground. In theory.

In practise, even if there was some voltage across the voice-coil, it wouldn't be worse for the mic with the gizmo than without is what I'm saying.

Unless I'm overlooking something?

 

[TheWinterSnow]

your not overlooking it i don't think, the 48v never sees the voice coil, well in part that condensers don't have a voice coil, but a capacitor, however the voltage never sees that voltage usless is was used to apply a DC voltage to a condenser. This will only creat a DC offset which is undesired. The 48v goes throught the preamp stage of the mic, which eleveates the potnetial of the capacitor to 48v of the circuits ground, at least that is how I understand the threory of condenser mics.

I do notice a sound difference on the guitars though, the higher resistence high end is more natural. Still considering the resistences of mic pre's and their respective mic are usually in the 800-2000 ohms which I beleive most are in the 1.6k area, you should try doubling the 800 ohm resistence and give that a run, that should give you a better result Matt.