DamirBL wrote:Hi, new guy here. Got a question about xlr splitters:
How bad for me would it be to use this kind of splitter:
It's a terrible idea! :o Don't do it.
...the only purpose of it would be to take 2 overheads into one channel... Are there potential problems with phantom power in this instance?
Yes, there are lots of potential problems when you're combing phantom powered mics...
You can often 'get away' with the parallel combining method if you're using passive dynamic mics, but even then it's not a great idea.
With phantom powered mics, the most immediate problem is that you'll be halving the phantom power voltage available at each mic (because both mics pulling current through the same phantom supply resistors will reduce the source voltage twice as much!) The effect of that is likely to be a substantial reduction in the microphone headroom and increase the transient distortion ... which isn't helpful when you're miking up loud things like drum kits ...
Another practical issue is that the low source impedance of the second mic will heavily load the output of the first mic (and vice versa), again reducing headroom and increasing distortion.
The good news is that you won't permanently break anything by doing it... but there is a significant risk that the sound quality from the combined mics will be seriously degraded. Depending on the circuit design of the specific mics you're using, you might get away with it... but in my experience it's more likely to be problematic than successful.
There's also the fact that you will inherently be creating a virtual single mic out of two mics which are, presumably, spaced apart. This is likely to result in comb-filtering colouration, further degrading the overall sound quality (making the cymbals sound phasey)... and it will be in mono, of course... when the whole point of using two overheads is usually to create a stereo effect!
Personally, I'd reduce your drum mic rig to a single overhead if you've run out of channels on the mixer (or free up another channel by ditching something else)... but if you really insist on doing this the correct method is to use a transformer combiner. There are some cheap and cheerful options around, such as:https://www.studiospares.com/Microphones/Splitter-Combiners/Studiospares-RED504-Microphone-Combiner_458230.htm
Or better engineered, but more expensive options such as:https://www.canford.co.uk/Products/20-345_EMO-E345-MICROPHONE-COMBINER
But these are just the first two that came up in a web search... there are plenty more along similar lines from other manufacturers. I've used the EMO and can vouch for it. I've not used any of the others... Sound quality is basically dependent on the quality of the internal transformer -- so the better the transformer, the better the resulting sound... and the more costly!
Also note that some mic combiners don't pass phantom power through to the mic sockets at all; some only pass to one of the input sockets, and some to both...
The EMO unit I listed above (which I have used and know to be a very good product) comes configured not to pass phantom at all, but a couple of internal jumper links can be moved to pass phantom power through to one or both inputs.
We as a band are using this mixer for rehearsals and it seems as though we are soon going to be needing another channel input, which we don't have; all of them are already taken...
If it's just for rehearsals, you really don't need two overheads! (You probably don't need any mics, really!) ... So I'd say save the money and the hassle... ditch one of the overheads and don't worry about it!
Edit: And I'm pleased to see that's the general concensus of the illuminati, too!