Mixers/Consoles Using Pads on Mic Levels... Your opinion?

[Brentgi]

Hello,

I once worked with a gentleman who firmly believed that using a pad on a mic level source would increase headroom and give you more flexibility. The problem here is that I cannot see the sense in this. I'm hoping that if there is a good reason to do this, that some one here could explain it to me.

Speaking of gain structure, the same gentleman has a practice of adjusting the input gain at a lower level and using the compressor's makeup gain to adjust. I also do not agree with this practice.

So I'd like your opinion on the matter(s). Agree or disagree, I'd like to hear why.

*EDIT* I am referring to using the pad on the console. I can certainly understand using a pad built into a mic for it's designated purpose.

 

[TJCornish]

If he means "headroom" in the sense that the padded signal is further from the 0dBFS ceiling then I guess that's true, until you add that gain back in somewhere else, via the input gain, or fader, or both. Now you're back to your initial amount of headroom, but you have gained 15-20dB more noise floor, which reduces your dynamic range and signal to noise ratio.

Using a pad on a line level source may make sense, using a pad on a mic-level source does not.

There are various kinds of gain voodoo that range from some fragment of truth from a particular piece of equipment 30 years ago to outright misunderstandings or mysticism. If the first gain stage of the channel is really terrible - maybe it is very noisy or distorts at a certain level you might need to add gain somewhere else, but that's certainly not the case with reasonable equipment or normal practice.

Standard practice is to send the mixer a good balance of level vs headroom. 30 years ago that required more management as analog circuitry was noisier. These days, shooting for -18dBFS or so from your preamp is usually a good starting point, and rarely is inadequate headroom or high noise floor a problem.

 

[RonHebbard]

Hello,

I once worked with a gentleman who firmly believed that using a pad on a mic level source would increase headroom and give you more flexibility. The problem here is that I cannot see the sense in this. I'm hoping that if there is a good reason to do this, that some one here could explain it to me.

Speaking of gain structure, the same gentleman has a practice of adjusting the input gain at a lower level and using the compressor's makeup gain to adjust. I also do not agree with this practice.

So I'd like your opinion on the matter(s). Agree or disagree, I'd like to hear why.

When I purchased my AKG CK1 and CK5 condenser mics, I purchased their -10db pads which threaded in between the capsules and the C451EB pre-amps. I only threaded the pads in if the capsules were in danger of over-loading / distorting their pre-amps. I also had four AKG C414EB's which, in addition to their four-way pattern selectors, also had switches for flat or two choices of bass roll-off / high-pass and two levels of padding between their capsules and pre-amps. I only used the pads if I felt the capsules were close to overloading their pre-amps. My theory was / is; AKG's a pretty reputable company. When they designed their mics and pads as a system, they knew far more about their capsules and electronics than I'd ever know. If I was going to pad the mics anywhere it'd be with their pads where they felt they were possibly required. I'd definitely use my AKG pads before I'd ever consider padding my Yamaha console inputs. As to your second query, I'll leave it to others to debate, just far, far too many variables for the likes of me to wade into.
Toodleoo!
Ron Hebbard.

 

[Colin]

Sounds pretty backwards to me. Pads are for preventing clipping. Alternately, they're for a hot signal that isn't clipping but that you want to run at a low level (pad allows you to still run fader near unity). If you use one on a signal that isn't too hot and then gain up in a later stage, you're adding noise, at least in analog. In digital you don't get so much noise from the gain stages in the desk, but you're still adding a step you probably don't need to.

So as a standard procedure it isn't good practice, but I can imagine times when it might be a good idea. When I used to use the Yamaha digital consoles, I would play games with pads and late gain stages because their mic pres had very audible steps in them. As you approach the top of each step they get real noisy, and it seemed like level-wise I'd always want to be right in that noisiest spot, so whatever I could do to live in the middle range of those preamp steps instead would sound better even if it meant engaging a pad and using a later gain stage to make it up.

 

[themuzicman]

Hello,

I once worked with a gentleman who firmly believed that using a pad on a mic level source would increase headroom and give you more flexibility. The problem here is that I cannot see the sense in this. I'm hoping that if there is a good reason to do this, that some one here could explain it to me.

This makes zero sense, as others have said. You want the cleanest signal you can, and by padding down a mic level source you're only going to add more noise in from the pre-amp.

Speaking of gain structure, the same gentleman has a practice of adjusting the input gain at a lower level and using the compressor's makeup gain to adjust. I also do not agree with this practice.

Again, another instance in which you're adding more noise into the system that you don't need to be adding in. Unless your preamps are especially noisy this offers no practical purpose other than distributing your gain structure in very strange places. On a digital console you're now two clicks removed from having access to gain, and on an analog setup you're reaching for the compressor rack trying to hit the right knob! My general rule on compression on vocals is you don't add it in until you need it, and then you're using it to bring transient peaks quieter that fader moves can't handle quick enough or gracefully enough. On the band side of things you're using it to shape the sound, not necessarily for gain control.