active or passive splitter box?

[mortenbrekke]

Hi everyone

Should I buy another passive microphone splitter box, wait, save money and buy an active splitter box, or just save the money?

Me and a friend have a remote recording gig based around Alesis HD 24 and adat-preamps/converters
(presonus digimax, focusrite octopre, m-audio octane)
I already own a 16-channel passive splitter box without transformers. I have used this three times without any problems. I have also tried to use "direct out" from the live-mixer, and I prefer to use the splits because it gives you more control over the input-signal, and more independence from the live-technician. However, I would like to expand to 24 or 32 splitter channels. So should I go with active or passive split-channels?

An active splitter box seems to be the best, because a passive reduces the microphone signal-level from 3-6 decibel, while the active maintains the signal?? Is this true, and how important is this signal-loss for audio quality?

When I record I usually stand by the mixing deck (FOH?) or if I find space, I can split the signal beside the stage and stay somewhere close. This means that I need much shorter cable-runs than the people using recording trucks. Does this mean that it is not as important with active splits, as compared to the trucks..

This is my my first post on this forum. I learn alot and get much of my motivation from reading these threads about remote recording. Thanks.

[paulhurt]

This is interesting, as you seem to be in a similar (ish) position to me. I'm currently working with a 24-channel transformer-isolated splitter/stagebox contraption of my own design (I keep intending to post some pictures - and I will - I think it's pretty cool, even if I do say so myself).

Thing is, my splitter is purely passive. I can see a point in the future when I'm going to want more splits, and 1) I'll probably go active 2) I'm damn sure I'm not building my own again (this one took me two years! Although, given some recovery time I may reconsider. I like a challenge.)

I was only looking at the XTA active splitter today. Cool design, and not as expensive as I thought they'd be. Why didn't I realise they were built in the UK? (probably because the only person I know who mentions them is in the US!)

Having said all that, I'm guessing you and I are working on very similar levels of gig with similar moderate lengths of cable run, and I have not yet encountered a problem using a passive splitter. I'm only saying I'll go active because I can't see a reason not to.

In a lot of ways, I suppose I'm the wrong person to be dishing out advice, since I have no personal experience with active splitters. However, I imagine that you'd be as happy with a passive system as I am as long as:

1) You're not trying to drive 300' of cable with passive transformer splits of dynamic mics - and even then it might be fine.

2) You're not constantly splitting ordinary passive (as opposed to Royer 122) ribbon mics - and even then it might be fine.

3) You're not splitting the output of the venue's passive splitter - i.e. cascading splitters, at least when the driving splitter isn't an active one. Most of the gigs I do they don't even know what a splitter is - monitoring usually run from FOH - so I'm safe.

The advantage of a passive splitter? No need to find a safe power source. If you find you need to place it near the stage, away from the saftey of your recording spot, I'd always be very nervous that someone will yank a cable in the dark by mistake or intentionally pull a plug not realising what it is. I don't see how dual redundant power supplies will save you from that. Hope I don't really need another UPS for an active splitter!!?

Quality-wise, let's put it this way, although I'd always prefer the direct, I have no qualms about recording off the transformer side on my splitter. Apart from a very subtle level drop, you really cannot tell the difference, and I've tried the reversed-phase trick. Using Lundahl transformers here.

I'd definitely get away from a brute-force parallel-wired non-transformer-isolated splitter though as I think one day it'll bite you in the ass. All those potential (pun not intended) ground issues? Scary.

So what am I saying? Passive is almost certainly fine 99% of the time for what (I think) you and I do. Active great if you can afford the premium, like the rackmount format, and don't mind the extra power cables.

I'm not sure if that's really an answer - I'm not sure I remember the question - but it's late here and I really should stop rambling and go to bed. If anyone wants to tell me I'm wrong about any of this, please do. I'm positively interested in other people's experiences and perspective. My whole philosophy is to never stop learning.

Will shut up now :-) Cheers

Paul

[mortenbrekke]

Thanks for the reply. I ended up buing a 16 channel Whirlwind passive splitter box with no transformators. And I am very happy with it. I have never experienced grounding problems. It is also possbible to secure oneself against this kind of trouble: the problem is less likely to occur if you use the same power supply as the mixing desk. If I use another power supply, then I could could check the power supply with a voltmeter,(dont know the exact english words- with "power supply" I mean the thing that sits in the wall where you plug in your electrical cables) and compare this with the power-supply in the mixing deck. If there is a difference, then there might be a problem.. so if I do this at least a day before the gig, I have time to find another power-supply or another setup.(an electritian told me about the volt-meter, but I have never tried it out.) If I am ready for the soundcheck, then we can test the microphone-lines. If there i s hum on a line, then the PA-guy wont use it. (this has happened sometimes, but I dont know it is due to my cables.)
About signal-loss due to passive splits: I dont think this is a big problem. The signal that comes through the split is quite strong. I cant turn the preamp-gain that high before it overloads the converter. And I have never heard a PA-person complain about signal-loss.
For me the passive splits without transformers are a good solution. The alternatives are more expensive and heavier to drag around. But if you are a professional that needs 100% reliability, I can understand the need for transformers and active splits.

Morten

[edwinhurwitz]

I would judge each split style by the individual unit. I use passive splits with Jensen transformers. Absolutely no problem with level or anything else. I would much rather have a passive split than an active with crappy electronics. Transformers don't add noise but active circuits do create noise (although with a good design, it's negligible and certainly in the heat of a live gig, unhearable). Personally, I wouldn't trust a simple Y cable arrangement, not only for ground issues (which can be got around with a shield lift at one end, anyway), but impedance issues. I guess it depends on budget and how often you use the rig. I have used the Horizon MS-4s with no problem (taking the direct for the recording) with no complaints from the house at all, so that might be a cheaper way to go to gain an isolated split.

HTH!
Edwin

[mortenbrekke]

hi

I never thought that much about impedance-problems. How can this affect the sound, and when can the problem happen?
m

[edwinhurwitz]

Originally Posted by mortenbrekke

hi

I never thought that much about impedance-problems. How can this affect the sound, and when can the problem happen?
m

I am no expert on impedance issues, but if you do a google search, I am sure you can come up with a lot of information. It really depends on what kind of mic you are using (or DI for that matter) and what the input configuration of the preamps are. I would imagine that if you are using really nice pres on one side with input transformers, splitter transformers would be unnecessary. That said, as a bass player, when I got my Lexicon G2 I was all excited since it had both 1/4" and XLR outs I wouldn't need DIs for it. How wrong I was. They were driven by the same circuit and all kinds of weirdness happens when both are used with certain boards (especially Mackie for some reason). My experience with impedance problems with microphones are mostly a dull and thin sound with decreased impact. With good transformers (jensen and the like), the mics regain sparkle and impact. I also try to get a direct signal path with the transformer split going to the PA where it's a little less critical. However, given that more than half my splits are transformer isolated on both sides, these days I get the majority of my signals going through the transformers. Still sounds great. Very punchy kicks and sparkly cymbals. If you want to check out some of my results, see www.zillamusic.com and see if there are any samples of their new CD Egg. I didn't get to mix it, but I did all of the tracking on location. We just finished three more gigs that turned out even better.


HTH
Edwin

[mortenbrekke]

Thank you for the detailed answer, edwinhurwitz, it made me think about my next audio-purchase.. I am looking for another 8 channel preamp (having sold my octopre and m-audio octane) and until now I have wanted to buy transformless C84 preamps from Seventh Circle Audio (have to assemble them myself, a great challenge)
But this comment made me think otherwise:

"I would imagine that if you are using really nice pres on one side with input transformers, splitter transformers would be unnecessary."

Would it be wiser for me to get preamps with input-transformers, if this can eliminate some of the potential problems caused by using a microphone splitter without transformers?

Secondly, edwinhurwitz mentions impedance-problems with my setup. I have found that the preamp Audient ASP008 has "switchable input impedance". Can this option fix potential impedance-problems caused by the splitter?
thanks,