Lyric, Venue, XLR and impedance

[timkjuk]

I've just installed the Lyric in my Martin D1 and bought the Venue DI. Since I don't have any amplification of my own yet, I hired a rehearsal studio in my local community centre to try it out. I connected the Venue to the 6 channel mixer/amp supplied with the XLR cable. The sound was terribly distorted. The local 'expert' said that this was because the impedance for the XLR input on the amp was either too low or too high (can't remember, I'om afraid!) for the input from the Venue. I was using a Shure SM58 mic into the XLR connection on another channel of the amp. I resorted to using the 1/4" jack output from the Venue and that was ok. However, I'm hoping to be able to use both the XLR and 1/4" jack output at my local music venue, the first to go through the PA and the second through an acoustic amp which can act as a monitor for me. The PA amp there is also a pretty basic 6 channel mixer amp (there are no sound guys as such - the resident band does its own sound), so I'd like to know if my 'expert' was right. I will have very little time to try the system out at the venue, since I'm only singing a few songs in the interval, and the band won't have a lot of time to spend on me, so I'd like to be as informed as possible before the gig.

In summary: could the XLR input on an ordinary mixer/amp combo be the wrong impedance for the XLR output from the Venue? If the amp has an impedance switch, which should I set it to?

Thanks

Tim

[Caleb_Elling]

Hey Tim,
Thanks for the question. There are a lot of local bands who do their own sound. So getting the right information can be a big advantage for the bands who really want to use their equipment correctly.

The Venue DI's XLR output has an impedance of 600 Ohms, which puts it (impedance wise) right where it should be for a mixer's mic input. The SM58 has an impedance of about 300 Ohms, so they are pretty close for low-impedance inputs.

The thing that I thing is happening in more closely related to output level, more then impedance. If the input gain is set correctly on the Venue (according to the manual), then the XLR's output level will be a pretty hot signal. Most professional-level mixers are designed with a wide range of gain, to accept hot signal levels as well as quiet ones. Small-format or cheaper mixers usually have a much smaller range of gain adjustability. So hot signals can occasionally overdrive the input and clip/distort the signal.

So if you run into a house-PA where this is a problem, lowering the gain on the Venue (or on the guitar) might be the only thing that you can do. It shouldn't be a problem in most situations though. My guess is that this is more of the actual problem that you were experiencing. Impedance is important, but all of our products are designed to interface with any pro-level audio equipment.

If you run into problems that make you think that there is another issue, please let me know.

[timkjuk]

So if you run into a house-PA where this is a problem, lowering the gain on the Venue (or on the guitar) might be the only thing that you can do.

Thanks Caleb. One of the other things I was going to ask you about was the gain. As I said, I have the lyric installed in a Martin D1 (like a D28 only cheaper!). I have to have the gain up to nearly full in order to get two green lights and an occasional yellow - never see a red. I pointed this out to the guy who installed it and he said he thought it wasn't a problem, and that he had installed it according the the instructions. You might have something to say about this - I did read one thread in which you discussed this with a Martin owner and said you thought that level was rather high. But I guess this doesn't affect the issue I originally asked about - I've got a lot of room to turn the gain down!

I have another pressing question for you, but I'll put it in another thread.

Tim

[Caleb_Elling]

Ok Tim,
The Lyric and the guitar will definitely play a part in the output of the Lyric, as well as how hard you play. So it's difficult to say for sure if there any something wrong in any specific case. In general, my thoughts are "if it sounds good, it's probably ok". The gain range of the Venue is designed to work with a really wide range of systems, so it's not always "predictable" where a specific pickup need to be set.

Feel free to post more questions here, or start a different thread if you think that the topics are too unrelated.