Electric Guitars: Amps vs. DI
Alright my fellow sound guys! Lot’s of you have been asking for this so here it is: the final verdict on micing a guitar amp versus using a line out/direct out from the amp and going direct in to the board. Each one has its own pros and cons so let’s take a look.
Let’s check out some good and bad things about each method first. For micing the amp there are a few obvious good things that have to deal with the actual quality of the sound. Mainly…it’s a lot better. I know that’s sort of a blanket statement/generalization, but I have yet to hear a direct output from an amp really sound as good as the amp itself.
Generally, how a direct output works is that it uses the signal after the preamp stage of your amp (where the gain, eq, etc, happen) but before the power amp stage (which would normally power the speaker). There are a few drawbacks to this: first, the power amp stage is a VERY important part of your amp’s sound especially if it’s a tube amp. Second, it bypasses the actual speaker which also has a tremendous impact on the sound you get. So if we look at the amp as three components: the preamp, the power amp, and the speaker, we’re missing two-thirds of the amp if we use the direct out. The direct output circuitry usually tries to simulate the sound of the power amp and speaker sections of them amp, and some do a good job, but overall there’s just something that’s missing when compared to the real thing.
Second, we need to talk about versatility. When you place a mic in front of a speaker, you can move it around, angle it different directions, and try different mics to get the perfect sound. With a direct output, you only get one sound. You can effect it somewhat with EQ at the mixing board, but it’s definitely more difficult to get that perfect sound when you lose control over all of those variables.
Now let’s talk about some great things about using the direct output. First, and this is a big one, is lower stage volume. This is HUGE for a lot of churches. We’re working in small spaces where there just isn’t the available space or volume to have a cranked amp sitting on stage. For situations like that, a direct output is perfect! You can eliminate tons of noise and still have something that sounds like an amp.
Second, is consistency. For all the benefit that changing the mic placement might give us, sometimes there’s just not enough time to sit there and tweak the mic placement for 15 minutes. Another case might be (if you’re a guitar player) the sound guy might not be experienced enough yet with proper placement and might end up causing more harm than good to your sound by moving the mic around. In situations like that it’s great to have the consistency of a direct output.
To sum it up, there are definite pros and cons to both methods. In the end, the sound of a miced up guitar amp is a better (or at least more accurate) representation of the true tone of the amp, but there are benefits to using a direct output too, like significantly reduced stage volume and greater consistency of tone. In the end, deciding which setup is right for YOUR context is the most important thing!