Topic: Has anyone tried mic1 + mic2 > headphone splitter > battery box > recorder ?

[fandelive]

Hi,

I've heard great quality recordings done with budget mics like SoundPros, Chruch Audio, Microphone Madness and so on...

The problem now : while one will get you great clarity in the vocal range and warm sound but will lack enough bass response, an other one will offer you deep bass but less defined (somewhat a bit "muffled") middles and highs.

So, I came to the point that combining two of them might get you a better "full-range" recording.
The problem is that I can't necessarily afford buying two good quality recorders (let's say two Edirols  ).

I was wondering what would be the "pros" and "cons" of taping a show using two pair of mics plugged in a headphone splitter?

Let's assume my lineage would be :
MM-HLSC-1 (75%) + CA-14 (25%) > headphone splitter > SP battery box > Edirol R09HR

I've seen nice headphone splitters here : http://www.monstercable.com/mp3/ipod/headphone_splitters.asp.

The first one looks great : http://www.monstercable.com/productdisplay.asp?pin=5151.
You can even set your recording to approximative 75% mic1 and 25% mic2 using the two independent volume controls.

The second one looks great too (http://www.monstercable.com/productdisplay.asp?pin=4934), but the setup between mic 1 and 2 might be even more approximative (no marks!!!) unless you do it at home and won't change it once you hear the sound at the show...

Even if it might be technically possible to do such a thing, is it relevant? (I've seen alot of matrixes mixing two sources, but in post-production).
Maybe it's better not to bother with independant volume control and just do 50/50?
Will one battery box be able to deliver enough power for two mics instead of one and will it lower the maximum SPL?

Please let me know what you think

[sunjan]

You can even set your recording to approximative 75% mic1 and 25% mic2 using the two independent volume controls.

If you throttle the signal this way, I assume it's done with some kind of attenuator, which is no good. That means you'd have to add more gain in the recorder. These potentiometers also have the ability to add more noise, if cheap components are used.

Secondly, if the Y-cable is able to pass on the battery power, the voltage is most likely shared too (depending on how the cabling is done), meaning that each pair of mics would receive 4.5V from a 9V battery.

Apart from that, I assume it can be done. Go ahead and experiment, but I wouldn't expect fantastic results.

The problem is that I can't necessarily afford buying two good quality recorders (let's say two Edirols  Roll Eyes).

You could also jump the gun on a H4n and try out the 4-track feature. At least it would give you more independent control over each channel. Not much more $$$ than the R-09HR.

[acidjack]

I was interested in attempting something vaguely similar, though my main goal was to A/B a couple of different pairs of mics. 

I picked up a used JB3 ($60) in the YS to be the "B" deck.  Not as good as an R-09HR, but it should do fine for recording with the mics you have using the line-in.  Only bad thing is it's only 16bit, so you'd have to do most of the post work in advance on your (presumably) 24bit R-09HR file, downsample to 16, then mix the two.  I have not tried actually doing it yet, but can let you know the results once I do. 

If you had two battery boxes, it seems to me that perhaps if you went:

mics>BB (for each set)>splitter>R-09HR that might at least solve the voltage problem, but there are other people who can answer that question here better than I.  Also, if you have to buy another battery box, you might as well just buy a used JB3.

That said, if you want to attempt it, I have an SPSB-8 I'm trying to sell...

[fandelive]

First, thank you for your answers.
I'd like to say I'm french and even less "hot" when it's about electronics subjet... So thank you for your patience. It's greatly appreciated.

If you throttle the signal this way, I assume it's done with some kind of attenuator, which is no good. That means you'd have to add more gain in the recorder. These potentiometers also have the ability to add more noise, if cheap components are used.

I first thought these independant volume controls would have given me kind of a "microphones balance" option with the choice of focusing more on one pair of mics than the other.
I was thinking about getting more highs and middles from the HLSC's (thus the 75%) and more basses from the CA-14's (thus the 25%).
For example, that would have mean set the HLCS's volume (balance) at 10/10 and the CS-14's volume (balance) at 7.5/10.

But that will only result in getting a mix with more gain (and potientially more noise) from the HLCS's and less gain (but still potientially even more noise) from the CS-14's, you're right!

I already did some tests using a cheap (though it has gold-plated connectors) headphone splitter with no volume control option and the two mics I have.
Test lineage : Sony ECM-717 + SP-BMC-12 > headphone splitter > SP-BBox (9V) > Edirol (line-in).

Left and Right channels let me hear both mics, which is a good point. And I don't think I got more noise from the splitter (no potentiometers).

So that's ok, I'd better get a basic fine crafted headphone splitter with no volume controls so it won't affect the mix.

With that being said, I know that each microphone will have a different input level (one will naturally record at a lesser or greater volume than one another).

Which mic specifications should I check to make sure both pairs will record per se at approximatively the same volume? Is it the open circuit sensitivity?
I still need at least an equally balanced mix.
What would be the threshold gap between two mics when you start to get something unbalanced?

Secondly, if the Y-cable is able to pass on the battery power, the voltage is most likely shared too (depending on how the cabling is done), meaning that each pair of mics would receive 4.5V from a 9V battery.

I couldn't notice any problem during the few tests I've made with my ECM-717 & SP-BMC-12 (no high SPL situations). Both sounded as they would have sounded if used separatly.
There's a small battery inside of the ECM-717, so it might have helped...
Considering that, the lineage was :

ECM-717 (powered) + SP-BMC-12 > splitter > SP-BBox > Edirol (line-in).
Does that make any difference or has the ECM-717 only got the power of the SP-BBox?

What kind of trouble am I supposed to get? Not being able to use the mics at full specs (full dynamic range, threshold SPL)?
How can I detect them?

HLSC's requires a bias voltage of 1.5 to 12 volts D.C. (also known as plug-in- power) or a battery module.
CA-14's must have a 5 volt to 9 volts supply.

So one single 9V battery box is not enough to make an uttermost use of each mics best possibilities (full dynamic range, highest possible SPL threshold)? 

[sunjan]

With that being said, I know that each microphone will have a different input level (one will naturally record at a lesser or greater volume than one another).

Which mic specifications should I check to make sure both pairs will record per se at approximatively the same volume? Is it the open circuit sensitivity?
I still need at least an equally balanced mix.
What would be the threshold gap between two mics when you start to get something unbalanced?

Secondly, if the Y-cable is able to pass on the battery power, the voltage is most likely shared too (depending on how the cabling is done), meaning that each pair of mics would receive 4.5V from a 9V battery.

I couldn't notice any problem during the few tests I've made with my ECM-717 & SP-BMC-12 (no high SPL situations). Both sounded as they would have sounded if used separatly.
There's a small battery inside of the ECM-717, so it might have helped...
Considering that, the lineage was :

ECM-717 (powered) + SP-BMC-12 > splitter > SP-BBox > Edirol (line-in).
Does that make any difference or has the ECM-717 only got the power of the SP-BBox?

What kind of trouble am I supposed to get? Not being able to use the mics at full specs (full dynamic range, threshold SPL)?
How can I detect them?

HLSC's requires a bias voltage of 1.5 to 12 volts D.C. (also known as plug-in- power) or a battery module.
CA-14's must have a 5 volt to 9 volts supply.

So one single 9V battery box is not enough to make an uttermost use of each mics best possibilities (full dynamic range, highest possible SPL threshold)? 

You have a point in that the signal of one pair might be much hotter than the other, but then again you are matrixing them on the spot, so you wouldn't notice a huge difference.
If your aim is to catch both low and high frequencies, this is easily remedied in post, so don't sweat it.

Think about it: miniature cardioids are all pretty similar as regards to the pick-up pattern and frequency response. And if you indend to body mount both pairs, there won't be a huge difference. Both pairs will pick up pretty much the same sound!
It would make more sense if you matrixed the cards with a soundboard signal, or configure one pair of cards on a stand while running the omnis binaural.

Throwing in the ECM-717 in the mix is even more pointless. The frequency range is only 100-15,000 Hz, which means that the entire range is already covered by your SP-BMC-12 (20- 20,000Hz).

At least you don't have to worry about powering the ECM-717. According to Chris Church, they are designed to run on the internal battery only, and won't benefit from any additional power.

I'd say, just focus on running the best mic that is in your possession. If there are any perceived shortcomings with frequencies, try to equalize them out in post. If you're still not happy with the results, it's time to upgrade.

[aleal5687]

I did this a few years back. I was happy with the results.

Sonic studios dsm6p->(battery box)->20db attenuator->y splitter ->Line in d7
Coresound Cards->batterybox->y splitter->line in d7

[fandelive]

I'd say, just focus on running the best mic that is in your possession. If there are any perceived shortcomings with frequencies, try to equalize them out in post.

Ok, you convinced me
I'm gonna run MM-HLSC (XY if possible in order to create some good space effect, but the mics will be clipped on my body...) > SP-BBox > Edirol and try to add some bass in post if needed.

Thank you very much for taking your time to write those newbie-friendly explainations. Greatly appreciated!