Monitoring issues while recording acoustic guitar

[sachit]

I'm having real trouble monitoring myself playing when I'm tracking.

I'm recording myself playing my acoustic guitar. My MOTU Microbook allows me to set up hardware monitoring, so I monitor the guitar through my Sennheiser HD205 cans. Problem is, that I can't hear the guitar in my headphones when I'm playing it. However high I might push up the headphone mix, it's not distinguishable from what I can hear of the guitar itself 'leaking' in. So it sounds almost the same whether I wear headphones or not. Sometimes I catch a bit of the picking noise(well above 2kHz, I think) but I can't hear the string fundamentals, chords and anything else.

This has caused a million problems for me. The biggest problem is that I can't find out what it's sounding like until I record it and play it back in Logic. So I can't decide where to position the mic, I don't notice any tonal issues and I can't reliably use the DSP EQ and compression the Microbook offers.

There has to be some simple solution to this that's evading me. I've tried googling and searching the forums, but no luck.

Any suggestions?

[BobRogers]

Why are you using headphones at all? Are you overdubbing? Even if you aren't the one playing headphones aren't the best reference for positioning the mic or setting EQ or compression. Get a ruler and do one long test track with the microphone in several positions. Announce the measurement before you play the test music. Then listen through your monitors. Much better way to decide on placement. You can do basically the same thing with the DSP eq and compression, but if you are pretty new to this you can learn more playing with the plugins in logic while listening through monitors. Are the plugins in the microbook that much better than the ones in logic?

[RemyRAD]

It's possible that your headphones may be of an inverted phase? If the microphones are not in phase with the headphones, things you are recording along with their outside influence will tend to cause cancellation of the signal that you perceive. Sort of like those battery-operated noise isolating headphones that are not playing music or anything. In essence, they are fighting outside noise with amplified noise that has been phase inverted. So you perceive much less of the noise. Not every piece of equipment is phase accurate from input to output. Some things by their virtue of design, creative phase inversion where no one thought this would cause any problems. This scenario is similar to a rock band on stage at your local my club. The lead singer & guitarist is shouting he could not hear himself in the monitors. When they try to turn the monitors up, they get feedback and the guy still can't hear himself. That's because the amplifier that was feeding the speaker is not phase coherent to the microphone. That means the louder he yells and the microphone and the louder the monitor is, the less the performer can hear of themselves. And hitting the phase switch on the audio console doesn't always solve the problem. Sometimes it requires that the output of the amplifier feeding the monitor speaker must have the polarity inverted there so that the excursion of the monitor speaker is positive towards the performer and not sucking... in.

You can exhale now.
Mx. Remy Ann David

[sachit]

Thanks for replying!

@BobRogers, I know using headphones is not the best way to monitor. I'm recording to a very basic background score, not starting from scratch. I think that still couoverdubbing, right? Thanks for the ruler idea, that really sounds smart. I'm going to start doing that. However the DSP EQ and compression will be hard to do that way. I can even manage compression, but the EQ will be cumbersome that way.

Actually I am new to this, but I've been using the DSP stuff for quite some time, and I'm confident printing some basic EQ'ing and compression. I'm not sure how much better they are than the plugins onboard Logic. Logic's plugins are quite good, on the whole. But the DSP tools sound totally different, a sound I like. It colours the audio in a very different way as compared to Logic's plugins. It gives the music a slightly warm feel. More than once, I've got tones and sounds that just don't sound like they were made with a cheap mic. I would really love to use them.

It's possible that your headphones may be of an inverted phase? If the microphones are not in phase with the headphones, things you are recording along with their outside influence will tend to cause cancellation of the signal that you perceive.

That's a very intelligent answer, thank you very much. I did think of this myself, and I hit the Phase button on the MOTU software console(called CueMix). It did improve stuff, I could hear something through my headphones, but it was nowhere near proper monitoring. Thanks for the information, I think I'll need to check the phase more carefully, I just arbitrarily tried that. Perhaps the phase rotation wasn't a full 180, like you said.

But even if the phase issues are solved, it still won't fully solve the problem, because I find it very difficult to distinguish between what I hear acoustically from the guitar and what the headphones feed to my ears. Still, I'll try this stuff out.

[RemyRAD]

If your headphones won't play loud enough when they are plugged into the MOTU or whatever audio device you are using, you may simply need a amplifier? Many different brands of headphones impedance varies widely between different manufacturers along with their efficiency level. Some headphones plugged into certain pieces of equipment will nearly blow your head off. Where other headphones plugged into the same equipment are hard to hear. Most headphones range from 8 ohms to 2000 ohms and everything in between. Efficiency differs as widely as different impedances. So you might be able to solve your problem by merely changing to a different brand and manufacturer of headphones? On the other hand, having a dedicated headphone amplifier will likely come in handy, numerous times anyhow.

I could use a good curry?
Mx. Remy Ann David

[sachit]

Maybe I need a headphone amp, but firstly, I cannot think of too many uses for it, since I don't intend to use more than one pair of headphones often. Also, the headphones are plugged into a dedicated headphones jack in my interface, so shouldn't the impedance be optimal? Otherwise it's kind of useless to brand an output as a headphone output...

And how will I know whether the headphone amp will be suited to my headphones or not?

[sachit]

Is it common for engineers to buy headphone amplifiers? I thought they'll only be useful if a large number of headphones are being used....

[RemyRAD]

It doesn't matter whether your headphones are plugged into your audio interface. Most amplifiers for headphones are the same as used for speakers, just a lot lower in power. They are generally designed for a low impedance load of approximately 8 ohms. But just because speakers are mostly 8 ohms, that does not necessarily hold true for lots of headphones out there. Most headphones range anywhere from 8 ohms to 2000 ohms. So if you're plugging a 2000 ohm headphone into an amplifier designed for a 8 ohm load, it might be too loud or not loud enough. If you have an 8 ohm headphone from one manufacturer and an 8 ohm headphone from another manufacturer, that doesn't mean they will play at the same loudness level. The loudness is determined by the efficiency of the transducer regardless of the impedance. Most audio interfaces work adequately with most headphones. However, sometimes people like their headphones louder than the device can deliver. In those situations, you must use some other type of additional amplifier. Most of those headphone amplifiers are designed for at least 4 headphones and have 4 separate small amplifiers inside. Years ago I needed a simple headphone amplifier and here in the United States, we have a place called Radio Shack which I like to call Radio Schlock and/or Radio Shaft. This was not a high quality amplifier, it was just a little piece of crap so I could get my headphones up to the level I needed to be able to hear things properly with. It was basically a couple of 5 WATT IC chips. The little device cost me $30. Some of my Sennheiser headphones are 2000 ohms they are not 8 ohms but they are also not considered high impedance. There really aren't any decent high impedance headphones that exist.

An actual recording studios, we don't use crappy " headphone amplifiers ". Instead, we either use highly specialized and expensive systems or, you design your own which is what I've done. My headphone system is run from a single 40 W per channel stereo amplifier. My headphone distribution system utilizes a series of parallel and series resistors to both balance the load on the output of the amplifier while limiting the current available to the headphones, with small customized headphone boxes for each headphone. This is single amplifier can feed a single headphone or it can feed 100 headphones. Please be careful though, you do not want to connect a pair of headphones directly to the output of a stereo amplifier designed to be feeding speakers. It's a good way to destroy your headphones it's also a good way to permanently lose your hearing with the accidental flip of a switch. That advice section comes from the school of hard knocks. When I was a young teenager, I connected a pair of headphones to a 10 WATT amplifier. I flipped a switch and virtually lost my hearing for an entire week! I wasn't sure it was going to come back? I was terrified. Thankfully there was no lasting damage. It's also another reason why I've never really gone to any rock 'n roll concerts and don't hang out loud nightclubs either. I'm supposed to be a professional listener so I best be careful.

I do look funny though...
Mx. Remy Ann David

[sachit]

Wow, thanks for the detailed answer!

Your headphone distribution system does sound interesting. For me, I guess, a simple headphone amp should do... but it sounds basic enough that if I mess around with some components I can manage building something really basic myself... I mean, it's basically an amplification system. If I have a suitable amplifier somewhere(maybe behind the headphone jack of some old unused CD player etc) then I could try. On the other hand, they're cheap, so if I can't manage something, I can always invest in one. I'll keep your suggestion in mind, I don't want to blow my heads or my head. lol.

It's weird though, the headphones are loud enough when I monitor mixes. Perhaps I need an additional boost when monitoring a mic 'coz it's much softer. I'll see what I can do. Thanks a million. The level of information you give is extremely rare to find for newbies like me who are trying hard to learn what they can off the web.

[RemyRAD]

For additional headphone amplification, even simple all-in-one amplifier IC chips which are reasonably inexpensive makes a lot of sense. And those are all made by a multitude of manufacturers all over the world. So, yeah, if you have an old CD player that plays your headphones much louder for you than your audio interface, you may want to gut out that amplification section if that were even possible? Though I doubt it? You'd be better with a simple perf board with a couple of 2 WATT IC chip amplifiers for an additional headphone boost. These will not be of high reference value quality but they will make your headphones a heck of a lot louder when you need them to be louder.

No cows were harmed in this process.
Mx. Remy Ann David