Karaoke Forums

My main bar recently re-arranged and got a pretty good sound system, and I am trying to use it instead of bringing my own system (talking speakers and amp here).

My problem is that for the sound it goes through a lot of "extra" steps now compared to my more streamlined system before.

Pretty much as it now stands for the music part of the sound it goes as follows:

Computer (volume control)
Compuhost (volume control)
My sound board (with mixer, several different volume controls)
Club sound board (volume controls) (the club sound board will not support the multiple mics I need for karaoke)
Club amp (volume controls)

Now my problem is that with so many volume controls it is getting to be a bit of a confusing situation for clipping the loudest parts of songs. Also it is important to not have too much of the amplification later along the "chain" as then I get a bit of background humm.

The ideal situation would be to to cut out the club sound board, to shorten the chain a bit but that may be a problem as the bar does not really want to have to have to wory about changeing its wireing around every time.

I understand each individual control should not be set at max but, my question is how much below maximum is optimal for such situations (assuming I am controling the final volume from a different point).

An additional complication is that the amp volume (final stage before the speakers) is not controled from the DJ station and the bar tends to want to keep it set very low, and that means I have to send a pretty loud signal from the earlier stages. This contributes to background humm and clipping.

So my main questions are as follows:
1 for the sound volume within the computer does it matter (in terms of clipping the maximums) when the sound is still in digital format. Ie can I set the compuhost or the internal computer sound to maximum or should both of them be set lower, and if so how much lower 70% 80%??. Would it be ok to set compuhost at 100% for example and the computer sound at 70% or would it be better to have both at say 85%. I know the final multiplier would be the same but I am talking about clipping the maximums here.

2. Within a sound board, I have a slider and a knob for each channel. Can I think of these two items as an individual unit in terms of avoiding the max (Ie knob x slider) <100% or should I make sure that neither of them individually is near 100%. Would clipping occur if either the slider or the knob is near 100%, or am I safe if the combined is well below 100%.

This is not a question about total sound volume but more about the overly complex chain of devices. I am not running the speakers anywhere near max but it would be nice to worry about as few volumes allong the chain as possible while at the same time minimizing clipping of the maximums, feedback, background humm etc.

A compressor would be the solution for the mics, but I should not have to worry about this for the music.

It is a lot easer for me to not have to worry about bringing my speakers, but I want to maintain a high sound quality.

You should read about gain structure. Basically what you want is for all the devices in the signal chain to clip at the same point so you have the most head-room possible with the least system noise possible. The "background hum" you have is probably a ground loop issue. Lift the ground on the cables you have connected to the house mixer. That may solve the hum. If it's in the house system itself, it isn't really your problem and they should look into it.

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Jeff Wheeler, moonlight DJ/KJ

I did not have a chance to write a detailed post earlier, but I will try to answer your questions better now.

On #2, the gain knob at the top of the channel strip is for the mic pre-amp. This takes the weak electrical signal from your microphones and amplifies it to professional audio line-level inside the mixer. From there, you have your EQ, AUXes, and eventually, the channel fader. The insert I/O jack is either before or after the EQ -- I can't remember which and some mixers even offer a choice via a DIP switch or solder points you can modify.

The reason this is important is you may have a compressor or gate connected via the insert I/O jack. That receives a pre-fader signal. So do pre-fader AUXes that you may use for stage monitors. If you engage the SOLO button and the meter/headphones are in PFL (pre-fader listen) mode, you can see the signal level at this point. This is how you should adjust the pre-amp gain. On an analog board with 20dB of headroom like the ZED, you probably want your peaks in the range of +0 to +6dB. Just into the yellow. You do not want the red clip light to come on -- that means the signal is being distorted and something needs to be turned down.

The fader is just another ordinary op-amp that controls the "volume" of the signal going to the main mix, as well as post-fader AUXes which are typically used for FX. That way the signal going to the FX processor is adjusted along with the one used for the main mix, so you don't change the wet/dry ratio of the signal every time you adjust the fader.

How you adjust the channel strip faders is totally up to you. As long as you have some head-room to increase the "volume" for soft singers, and some room to go down for loud ones, you are basically fine. Don't over-think this, just do what sounds right.

On the main fader, this is typically the master volume control for your audio system. Since you have a ton of head-room in your amps and speakers, you might run it really low. Alternatively, you might turn your amp knobs back so you can send a hotter signal from the mixer and get more use out of its LED meters. Finally, you could be technically correct by adjusting the dials on the amp so it clips at the same level as the output of the mixer clips. Being technically correct is not always the easiest or best thing to do though, especially with karaoke, which is not at all like mixing for a band.

As far as your #1 question about the computer volume goes, here is my take on that. The volume control in compuhost is a digital gain attenuator, and it should basically always be set to 100%. If you start using EQ or something in your karaoke program (I am not familiar with compuhost) then you may need to give yourself some head-room to avoid digital clipping.

The main output of your computer, the windows volume control or whatever, is also a digital gain attenuator, so generally you want that at 100% also. As long as you do not hear distortion that might be caused by over-driving the laptop sound card's op-amp, do not worry about turning it down. If you do hear analog clipping, reduce the windows volume control.

Finally, when you hook in to the mixer, use the PFL meter to adjust it so the musical peaks are somewhere around +6dB. Then use the fader to get the appropriate volume of music into the mix. If you need music in your monitors and you use pre-fader AUX sends for them, adjust those knobs as needed also.

One last thing to mention, your mixer probably has a lot of head-room, and +6dB is a conservative number for most analog audio systems these days. It is about right for recording, and it gives you some head-room for EQ. If you are doing things like adding 15dB of gain to a particular signal band using EQ, though, you should remember that when you think of how much head-room you have between that +6dB and the point where things start to clip, probably around +20dB.

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Jeff Wheeler, moonlight DJ/KJ

I have worked with almost the exact same setup, and once you get it right, it is nice not to have to set up your speakers. I took me a few weeks to get it the way I wanted.

I went from my players and 4 mics into my mixer. Just like you, I needed the control of my 4 mics on my mixer as I am acustomed. Instead of going from my mixer to my amp like usual, I had the two audio cables going into the club's mixing board, then into their amps and speakers. One video cable into the club's video system. It made for quick setup and tear down.

In my experience here, I pretty much kept the clubs mixer set to about 60% or so. The subs were so powerful that I set them about 40%, and my mixer at the usual 50% master output. As stated, it took me a while to get it right. If you turn the club's mixer to loud, then you have too much sensitivity. barley move a fader on a player or mic, and a huge volume difference. I set my amp and mixer so that I get the amount of sensitivity on my sliders that I prefer, while redlining on my mixer's output where I want it.

Might take a few weeks, or during the day with no crowd to get it right. Once you do though, if they spent as much on their system as my club did, you will be really happy once you get it the way you want.

Felix the KJ