Loudspeakers Choosing Speakers

[jkowtko]

If "the mics were clipping at the board" -- then you have a problem at the input stages and not necessarily the output.

Let us know what mics you are using, and what board you have.

I can tell you a few things right off the bat:

- If you solo (or PFL) the input channel and listen directly on your headphones, then you are listening to the input stage of the input channel, very early in the signal chain. At this point it is the mic system, channel input gain, insert jack, and possibly EQ (if you can solo past EQ).

- If the mic are all wireless, you may have to turn down the transmitter gain considerably to eliminate clipping. Also check the volume control on the receiver (although I usually always run the receiver at full volume) and make sure you have the mic/line output switch set to match the way you have connected to the input channel on the board. Since your board is old I would suggest bypassing the channel pre-amps and use a 1/4" TRS to the line input jack on the board -- and then make sure your receiver output switch is set to "line". Also from the receiver's end, use XLR or balanced output if available ...

- Another sanity-check is if you have an insert device plugged into the insert jack, pull out the insert and see if it clears up. I've mistakenly had a compressor on the input jack before with the dBu level on the compressor input/output jacks set to the -4 (consumer) level, which caused the compressor to clip. Switching it to the +10 (professional) level cleared this up.

Curious to hear what you find ...

Thanks. John

 

[museav]

The problem is that to get everything - guitars, bass, piano, various percussion instruments, etc. to come out clearly and properly throughout the entire auditorium, they have to be loud. Not overly loud, but loud nonetheless. However, when vocals are added on top of all the instruments, to get the vocals to come through at a loud and clear enough level, both the gain and the volume levels have to be set through the roof. Which then backfires on us because the vocals come in with the scratchy clipped sound. This usually does not happen when it's only one guitar and a vocalist, but it tends to happen more and more as instruments are added.

One simple approach on the mix is to get the vocals as loud as you can with them sounding good and then layer in the instruments under them rather than trying to mix the instruments and then get the vocals over them.

You mentioned that the mics were clipping on the inputs, but where were the faders and what was the console output level? If the faders are down and/or you have a lower level at the output, you may be able to turn down the channel gain/trim to get the channel out of clipping and then not attenuate as much elsewhere in the board.

For a simple gain structure check, the amp should be clipping at about the same time as the console output. There are small input attenuators on the back of the TOA amp and you may have to adjust those.

The TOA P-1060D is rated 200W/channel into 8 Ohms 1kHz, so probably a little under that full range. The Sx300 are certainly able to handle more, you might get another 5dB or so out of them with a 600W/channel amp, if you can't get enough out of tweaking the mixing and gain structure, then that would certainly be an option.

 

[lieperjp]

Let us know what mics you are using, and what board you have.

The board is a Mackie Sr32-4 VLC Pro, and a combination of Audio Technica ATW T220 wireless and Sure SM58 Wirelesses are being used. The AT's are used before the SM58's are. But it also happened last year when we used mainly SM58s with a few SM57s on the instruments. The guitar inputs are done via direct boxes of which I do not know the manufacturer or the model.

One simple approach on the mix is to get the vocals as loud as you can with them sounding good and then layer in the instruments under them rather than trying to mix the instruments and then get the vocals over them.

Yup. I've thought about that. I think it's been tried, but things are still to quiet. But it won't hurt to try again, that's for sure.

You mentioned that the mics were clipping on the inputs, but where were the faders and what was the console output level? If the faders are down and/or you have a lower level at the output, you may be able to turn down the channel gain/trim to get the channel out of clipping and then not attenuate as much elsewhere in the board.

I know the main level is at 0 dB and I believe that most of the mic settings hover around 0 db, varying no more than -12 dB or +6 dB. This is true for the vocals. I don't know about the other mics/inputs or the gain settings as I am not mixing, but I'm trying to help fix the problem.

 

[museav]

Since you say it is always clipping at the inputs and you are apparently using wireless mics, verify that you aren't peaking at the wireless mic receiver itself. If you are you may have to adjust the level on the transmitter. I also believe the A-T wireless systems are an unbalanced line output, so you may have to have the Mackie channels set for a line input and/or adjust the wireless receiver output levels (there's an level adjustment on the back of the A-T units). And you may also want to verify that there isn't excessive channel EQ being applied at the Mackie.

 

[lieperjp]

Since you say it is always clipping at the inputs and you are apparently using wireless mics, verify that you aren't peaking at the wireless mic receiver itself.

I will definitely take a look at that. It happened last year, though, too while using regular SM58s.

 

[waynehoskins]

As I see it, you have a few problems:
- horrible gain structure - learn how to do it right
- transmitter overmodulation
- insufficient power
- need for comps

As to gain structure, if a channel's Clip light comes on, turn down the input gain. I aim for peaks about 0 myself, which often allows me to ride the fader somewhere near 0.

Similar rule of thumb for transmitter gain: if the Clip light (if there is one) lights up, turn down the modulator's gain. If the receiver's meter reads too high, turn down the modulator's gain. When it's too high, either you're hitting a hard-clip circuit in the transmitter (which forces it to not overdeviate) or you're overdeviating the transmitter, making the radio link fail.

For power, the rule of thumb I go by (and this is just me) is to roughly match power handling of the loudspeakers with power of the amplifier. I try to match conservative ratings: continuous (or at least program) loudspeaker rating with 100-percent-duty long-term amplifier rating. In touring applications, the 2x factor makes sense; it gives you 3 dB more headroom, and your loudspeakers are likely to be able to handle that for short term. Never do I intentionally significantly underpower speakers; I like them to be able to play at Eleven if I need them to.

And as I've gone on in learning and getting better, I wonder how I ever lived without compressors years ago. At the church I've got 16 channels of compression, and sometimes I want more. The first thing you'll want to comp is your lead vocal.

 

[lieperjp]

As I see it, you have a few problems:
- horrible gain structure - learn how to do it right
- transmitter overmodulation
- insufficient power
- need for comps

Ok. I will try to learn how to set system gain structure.

Transmitter overmodulation - I will check into this. I am 99% sure this is not a problem, as when I was watching them during the show (one of the acts was really boring) I didn't notice any clip meters lighting up.

Insufficient Power: Mentioned it last night at the show. We will look into getting a new amp. Hopefully we can twist some arms and get some money.

Need for comps: How does one pick out a compressor? Is a driverack better than a compressor? That way we could get an EQ as well. I realize that you may not be able to answer that question online without seeing the room and system.

 

[waynehoskins]

Need for comps: How does one pick out a compressor? Is a driverack better than a compressor? That way we could get an EQ as well. I realize that you may not be able to answer that question online without seeing the room and system.

You need proper system processing.

You also will want compressors on individual channels. dbx 160A and 166A are nice compressors for the money vocals. Presonus ACP88 is nice as well.