Karaoke Forums

Can someone please help me fine tune my new karaoke system.
My system:
Mackie 808s Powered Mixer
JBL Mpro 215 Speakers
Pioneer V555 Karaoke DVD Player
Hisonic Wireless Mics and a Shure Beta SM58a mic.
The vocals are horrible sounding and I am getting alot of feedback. Please let me know what I can do or what other equipment I need to get in order to improve on the vocals and the feedback. I am greatful for any advice.

Thanks

Start out with low volumes and a "Flat EQ" and go from there... try to keep the Main EQ as flat as "humanly" possible and tweek the channels as little as possible also. Although some adjustments to both will obvoiusly be needed. If you can see if a Audio "Specialist" or Preferably "Installer" from your retailer will assist ya for a minimal charge or even better for free although the second is NOT very likely. (but don't ever be afraid to ask) as I have assisted many KJ's in my area Including Ron with system set up and dial in, (Karaoke with Ron, Here in New Mexico) Free of charge and it was sincerely appreciated. So it may not ever hurt to ask.

Also another thing is to learn to use and TRY to purchase a USED Real Time Analyzer (RTA) I have seen a few around lately, and seen 4 on E-bay this month. also I know where there is a great deal on a DOD model. So there are some affordable ones around.

It's best to have some one Teach you how to "ring out" a room for feedback. Most expierenced Audio engineers, and Tech's know how it's done.. but it's almost a necessity if the tools are not there to fight feedback, or you are new to running a sound system.

Welcome to KS and I wish ya well with the new system.

_________________
Brian D.
(BHB)

on the wireless mics... for sure read the instructions.

On my audiotechnica, they say to open the mic channels all the way, and as they feed into the individual mic channels on the mixer, I adjust them accordingly.

Feedback happens when the signal is too hot or distorted. Try turning down the stuff, and adjusting slowly from there. Don't be so quick to sing... take your time, turning on the music first, and getting it to sound right. Don't over amplify the signal from the player, either... most GOOD karaoke music will come pretty much ready to play. Then once your music is mixed right, then go for ONE mic, and then another.

Lonman's the pro on the Mackie products... but check www.mackie.com and get the pdf files of the owner's manual and the quick hookup guide and read them like they're gospel... for they are!

I find it best to save the files to your PC for quick reference, and not browsing them strictly on the net!

You'll need adobe to read these - if you don't have it installed, the net has the reader for free... just do a google search on "adobe reader"!

owner's manual - www.mackie.com/pdf/ppm_om.pdf
hook up guide - www.mackie.com/pdf/ppmseries_hu.pdf

Matt

Brainchild, here are some basic setup rules you might want to read.

The first, and possibly most important step in the basic set-up of your mixer is the proper setting of the channel GAIN control (if your mixer does not have separate gain controls read on to the next step). The channel gain control does pretty much what it sounds like: it sets the initial input gain level for that particular channel. Ever hear the term "Garbage in Garbage out"? Well this applies perfectly to the gain control because if the initial gain is not set properly, anything that happens along the rest of the signal path will suffer. If the gain is too low you'll likely get unwanted noise. If the gain is too high you will get distortion and lack of fader throw (or headroom). Basic gain control set-up is fairly easy. With the channel fader (or knob) turned off, slowly turn up the gain control while an signal is being input to the channel until the channel peak indicator flashes (it is optimum to have the input signal represent whatever will be present during the performance. ie. a drum mic should be set up with a drum signal, etc.). The flashing peak indicator lets you know that you have reached the clipping (distortion) threshold of the input preamp.

Back the gain control off a bit until the peak indicator flashes only occasionally during the loudest input signals. Don't worry about the brief peaking, most mixer's peak indicators light anywhere from 2-6 db before actually clipping Distortion) occurs. Use your ears though, if you hear audible distortion, back off the gain until it stops.

The second step of basic channel set-up involves the channel fader (knob). After you have set the proper gain you want to bring the channel fader up to what's called "Nominal" (typically half to two thirds up) Some mixer's peak indicators work for the fader setting as well so you can get a good idea of what your maximum fader settings are. Leave yourself some room for adjustment with your fader settings (if you max them out at set-up you can't turn them up later during the show). And as always, use your ears. If you hear distortion, back off the fader, even if the light's not flashing.

Now it's time to set the Master or Main faders (knobs). The gain controls on your power amps should be at least half way up to be able to achieve full output (some sound people have them all the way up - it's up to you). Typically for a live show you will bring the master faders up to approximately the same "nominal" level as your channel faders. Once again leaving yourself room for volume adjustments during the show.

Of course there are many variables in live sound (mic choice and placement, EQ settings, monitor set-ups, room shape, feedback, electrical problems, hum noise, etc., all of which will be covered in future Dr. Sound articles). The above are "typical settings" to be used as starting-point guidelines. Every system and every venue is different, but the basics still apply to everyone and you can save yourself a lot of trouble if you don't take shortcuts.

How do I deal with feedback?
The easiest answer is the one that most people are unwilling or unable to comply with, and that is simply: Lower your stage volume. You can have the biggest, baddest main PA system, blasting your audience into heart palpitations, and still keep your stage volume reasonable. Let the main system do the work. You will reduce the chance of feedback, and may actually perform better because you can hear yourself more clearly. Unfortunately, most performer's stage volume exceeds their system's "potential acoustic gain" (PAG) before feedback. This means there is a finite volume threshold in any given stage set-up that you can either stay below and avoid feedback, or exceed and then have to deal with feedback. One way of dealing with it is with EQ.

Graphic equalizers have long been the favorite of bands and sound people for helping to cope with feedback issues. While 10 or 15 band units can certainly help, the ones usually employed for feedback correction are the 1/3 octave, 30 band units. The reason units with more bands are preferred is because they allow the frequency spectrum to be broken up into much smaller sections (known as the "Q") and then manipulated more precisely, with less interaction between the sections. For example: if you are experiencing a feedback loop at 4 kHz, you can cut the 4 kHz band on a 1/3 octave EQ and not severely affect the adjacent frequencies (because you are dealing with only 1/3 of an octave or a "Q" of 0.33). Whereas with a unit featuring fewer bands, you would be affecting a much wider range of frequencies (up to a full octave or a wider "Q" of 1).So with a 1/3 octave unit, cutting at 4 kHz to alleviate the feedback loop, you aren't also cutting frequencies from 2 kHz all the way to 8 kHz as you would be with a 10 band (1 octave) unit, which can cause the sound to be dull and lifeless. Fully parametric equalizers can also be used to sort out feedback problems, but are typically limited by fewer number of bands (usually 2 to 4) and by price. The main things fully parametric EQ's offer over a graphic EQ's are variable frequency selection and an adjustable "Q". The variable frequency selector lets you find the exact frequency that is causing trouble. You could have a feedback problem at 4.2 kHz and with a graphic EQ, you would have to use the 4 kHz control to try and alleviate the problem.With a fully parametric EQ, you can dial in exactly 4.2 kHz and then cut it. Most fully parametric equalizers can adjust down to a "Q" of 0.1 (1/10 of an octave). This can really let you fine tune out a troublesome frequency without adversely affecting other desirable frequencies. Ultimately, graphic equalizers are easier to use and offer more bang for the buck for most bands and sound people.

Another way to help reduce the possibilities of feedback is with your choice of microphones and their proper placement. Most vocal mics feature a unidirectional "cardioid" pick-up pattern. You've probably seen drawings of this type of pattern. It looks similar to a mushroom or heart shape, indicating that it picks up in front and picks up much less from the rear. While called unidirectional, the typical vocal mic still picks up enough from the sides and rear to allow feedback problems. You could use a more directional mic but then there is more chance of a vocalist dropping out of the mix if they don't stay perfectly in front of the mic. Tight pattern, unidirectional mics reject feedback very well and are great for micing drums, amplifiers, and other stationary instruments, but a vocalist must have excellent mic technique to use this type of mic. Try to use mics that have good "gain before feedback" characteristics. When micing an instrument, place the mic as close to the source as possible (avoiding physical contact). This allows you to keep the gain on that mic lower in order to achieve the desired result. And since the gain is lower, there will be less chance of that mic picking up and re-amplifying any unwanted sound. Try to keep stage mics from pointing at or being too near any monitor speakers. Experiment with the angle of certain mics. Just a slight movement up, down, or to one side, can reduce a feedback problem. This is especially true on stages that have ceilings and back walls. The sound from the monitors bounces off of the ceiling and back wall at a certain angle. Changing the mic position can help the sound to bounce past the mic instead of directly into it.

Use of noise-gates and filtering can be of great benefit in the fight against feedback. Noise-gates can automatically shut off mics that aren't being used continuously (i.e.. Background vocals or horn section). The use of gating requires complying with the first paragraph of this section (keeping the stage volume down), for if the stage volume is too great, the gates will be triggered by extraneous noises and their purpose defeated. Filters, especially high-pass or subsonic types, can really help with low frequency feedback.

Digital feedback eliminators are available from several sources. These work anywhere from very good to not-at-all depending on the application. The most common complaint about these units is that while cutting feedback prone frequencies, they also cut desired frequencies as well. Also, some people complain that they are difficult to use/program. You will have to be the judge on these based on your particular situation and experience. In-ear monitors can greatly reduce feedback problems. They are widely used by top artists and can solve a variety of stage volume related problems. I personally recommend using a hard limiter on each channel to prevent hearing damage caused by peaks (accidental or otherwise). Once again, cost may be a limiting factor on a quality in-ear system including limiters.

I have covered some of the basics. There is so much more that it would take an epic to cover it all. Any and/or all of the hints and methods mentioned here may work or not work in any given setup or environment. There are many contributing factors, not the least of which, is the performer's and sound person's willingness to work together on considerations such as over-all stage volume and mic technique/placement. The stage configuration and construction materials, mic type and quality, mic/monitor placement, etc., will all affect the over-all outcome. There will be some set-ups that just seem to defy all logic and nothing you do seems to work. My advice is: when all else fails, turn it down.

Welcome to the world of sound!!!!!!!!!!!!

AllStar said it pretty it pretty well, especially when he advised to keep the stage volume down.

I'll try to keep my 2 cents worth simple.

First, don't over do the EFX, especially reverb.

Second, don't point the monitors directly at the singer.
Most speakers put the majority of thier sound out at 90 degrees horizontally and at 45 degrees vertically. This is called thier coverage angles.

Where you place, and where you aim your monitors can make all the differance in the world when it comes to feedback.
Even a few inches can have a dramatic effect.

This will ease the constraints put upon your equalizer leaving you more room to adjust the sound to the way that you like it the most.

Good Luck!
Kojak

I want to thank everyone for their suggestions. I fail to mention that my system is primarily for home use. The room size is 20x28 with the ceiling being 13' high. Not sure if I need to install any sound absorbing material on the walls. Again, any ideas will be greatly appreciated.

Thanks

That all depends...................you see, the biggest problem with sound is that it always DEPENDS

There are so many factors. What are the walls/ceilings made of, is the floor hardwood, tile, carpet?

One questions with too many answers.

I just moved into this house so its a blank room with dry wall all over and carpeted floors.

Thanks

Dry wall and carpets absorb sound. You should be good to go with that!