Karaoke Forums

Just got my UB1222fx mixer for home karaoke system.  I would like to have a dvd player, and MICs go into the mixer and mixer out to my home AMP.  Which output should I use to connect the mixer to the AMP?  CD/TAPE output or MAIN OUT?  I believe my AMP only take RCA connections.  What is the difference betweenn those two output?  Also, any recommended initial setting on the mixer?  Thanks.

If you opt to use the main outs you'll need a pair of adapters to convert the balanced connections to unbalanced.  Radio Shack carries these adapters for about $16 each (you'll need two) which have an impedence matching transformer in them.  You'll also need a 1/4" Male unbalanced connection (it looks like a mono jack) to RCA/phono Male cable to hook it up.  Again, a pair of these cables.  It's not the most elegant solution in the world, but it works.

Or... you can run from the tape output to your home amp.  Keep in mind that the 7 band eq is AFTER the tap for these outputs so it will have no effect on the output if you use the tape out.  The aux send/return on both the pre and post will work as will the built in effects (which are on the post send/return).

Please keep in mind this is based on my review of the block diagram on Behringer's website.  If someone has first hand knowledge to the contrary feel free to chime in.... I'm just an electronics junky doing the KJ/DJ thing for a short time...

I just bought the same mixer myself to add to my UB1832fxpro.

Best not to fire a home amp off it, but if you insist, then use the adapters and cables suggested above.

Consider finding a 100-200 watt used pro audio amp on the cheap and attaching your home stereo cabs to it instead. The mixer and pro amp will then be happily mated and the speaker cabs will do fine at normal living room sound levels.

Settings?....

Plug in your mic and set it's input using the LED at the top of the strip. That twisty knob will end up about 2/3rds cranked.  Plug your player into the dedicated CD input. Slide the masters up to unity(0db), and crank your amp up to 2/3rd's if home stereo amp, all the way up if pro audio amp....Then ease up the CD slider till you have decent sound pressure levels and then slide up the mic until it mixes well with the CD....Then sing like any happy fool with a new mixer.

If the neighbors complain, invite them in.

And if that doesn't work, get them a brochure of what you think they'd consider a more respectable neighbourhood  LMAO

jee

Thanks.  But what is the disadvantage to use the home amp?  Do I need to adjust the MIC strip EQ?  Also, which FX setting is best for karaoke singing?  Thanks.

Sometimes home amps don't handle incoming signal well if the signal volume varies a lot. It will most likely vary when you use a mixer. Professional amps don't have this problem.

The "average" best effect for vocals is hall reverb. For rock sometimes conventional delay echo is alright. Try them all out and you'll find out what you like best!

jee

It's a matter of failing to match proper electrical outputs to inputs. Your pro mixer is quite powerful and can deliver several (6-8)volts input into your nice home stereo amp....That can quickly overload it and fry the amp's input 'ziztors or whatever....If nuthin else, it just won't sound right.

Please remember that every component in your signal chain offers amplification (signal gain) and also must be able to handle the amplified signal it receives from the previous component ...(gain structure)....Starting with the mics.

Your mixer contains several stages of amplification, so by the time the signal leaves the mixer, it is usually way too hot for most consumer home stereo amps....That means you are overdriving your home stereo amp inputs and doing so can cause things to smoke.

The mic generates a very weak signal that must be amplified in the mixer by what is called the mixer mic pre-amp....There is a mixer mic pre-amp for each mic channel.  The mixer contains additional amps that sum all inputs and then deliver the summed and further amplified signal to master outs at what is called "line level".

The mixer is designed to deliver this signal into a narrow range of resistance that only pro audio amps offer. (impedance matched).

Impedance is simply resistance to current flow. Low input impedence allows higher current flow (more watts from the upstream amp), high impedence restricts current flow(less watts from the upstream amp) Trouble is, the upstream amp must see proper output impedence (load)to work properly or it too can fail or sound bad.

Output voltage is signal "pressure", that's the force that imparts the flow and keeps it moving.......So if you follow the theory so far, then high pro mixer output voltages cause high current flow that must be properly restricted by the power amp's built-in resistance to that flow..... Properly restricted means that the amp inputs must be impedenced matched to the mixer outputs or something will get overloaded and either smoke or sound crappy. ...Then either the mixer out's will suffer or the amp in's will take the heat.

Pro audio power amps are designed to accept line level output from pro audio mixers then further step up (amplify) them into voltages and current (watts)that your speakers will properly respond to.

If there is any one component in you home audio system that can be adapted to pro audio use, it is your speakers. Typically, home stereo speakers, like pro audio cabs offer either 4 or 8 Oms resistance(impedence) to current flow. Most pro audio amps are rated to accept either a 4 or 8 Ohm load and are happy as long as that range of load is connected.

The worse that might happen using home stereo speakers is that your speakers might experience over excursion from too-deep or over-accented bass or too high a power level from the pro audio amp....unless you clip the power amp.

All said, the most common cause of speaker failure (home or pro) is underpowering that causes the amp to clip and the speaker voice coil to overheat from the flat wave form generated when the power amp is clipped continuously.

Keith01 EXCELLENT POST!

I have a big supporter of using home speakers for Karaoke.  I'm now officially changing my tune.  Nope, didn't blow up my speakers but having steady gigs as a KJ and listening to 5,400 watts of power through three amps and six speakers versus my home speakers has left an impression on overall sound quality.  It sucks in a word.  Of course I wouldn't run 5,400 watts at home.

Outdoorplaces --

Who had friends over to do Karaoke on Saturday night and had the police show up telling us to turn it down.  

_________________
Despite the internet rumor, Karaoke is not Japanese for "drunk buffoon with microphone."  However, "rotation," is Japanese for wait your damn turn!

Thanks,

I think the greatest shortcoming of home audio speakers is that they can't reach out like pro cabs. That's because most home cabs don't use pro style horns, they instead use tweeters and small mid range woofers. Pro cabs usually use a large horn for highs and mid-highs, and a huge woofer for lows and mid-lows. That horn really reaches and keeps the highs and mid-highs brite to a much greater distance.

....And pro cab woofers usually have much more stroke meaning they move more air farther across the room whenever they thump. All together, that keeps SPLs higher and clearer over home style stuff.

Back to electronics compatability....I bet many here have noticed that most consumer cd players tend to almost clip your mixer stereo inputs when playing prerecorded music. I've had to split the cd inputs and bring each channel into two separate mic strips so I could use the input gain twistys to attenuate enuff not to get distortion....Later I bought a mixer that automatically compensated input gain on the stereo strips and would accept even the hottest cd player. That's another thing I like about Behringers new 1224 fxpro, it has a compensated cd input with it's own slider.

Thanks Keith01

I think I have to stick with my home AMP and speakers for now until I come up with some $$.  Thank you for all the information.  I really need to look at it again and again.

Should I use the MIC strip EQ at all?  And which FX (preset #) would be the best for the karaoke singing?

Thanks.

Sure use the mic EQ twistys, just cut and not boost first and take care not to boost anything into distortion....then remember to go back and retrim the mic input gain twisty cause adjusting the strip eq will change input gain. Read up on your board's builtin metering and you will understand. They give you a decent owner's manual that explains it.

Take care when connected to your home amp. Since you are not connected to a pro amp, start with your master sliders at bottom, Your CD slider at about -30, your home amp volume knob at about half, and then ease the mixer masters up and listen for distortion as you increase volume using the masters.

A note of info: That volume knob on your home amp is actually the amp input gain adjustment......Yep, just like the one on your mixer mic strip input....It trims the signal entering the amp, not leaving it....So limit the input from the mixer with it until you get a grip.

If you have the spec sheet on your home amp, examine it for "input sensitivity @ what level of impedence". That spec describes at what input voltage the amp hits full power. (You turn the knob down to raise what voltage the amp will have to see before it makes full power)  Then look at your mixer specs to see output voltages at different output levels. Do not allow the mixer to exceed the home amps input voltage spec. Remember that the "volume" knob on you home amp does not prevent the amp from going to full power, only the signal leaving your mixer masters can do that. So even tho you set the amp "Volume" knob near bottom, it can still blast full power if the mixer outs exceed whatever threshold you dialed into it.

You will learn that most pro amps go to full power once they see anywhere from .75 to 1.5 volts....In pro audio you use the amp input gains to match different amps in your stack so they all hit full power together. Other wise, if all amps in the stack are equally matched, then you should leave them cranked fully and use the mixer masters to control loudness. That allows the amp full headroom available and your music will be sound live and briter. So lets say you have one amp you use for the horns and another you use for the woofers....The horn amp input sensitivity is .75 volts and the woofer amp is 1.5 volts....Then the horns will be blairing well before the woofer amp is told to scream.....What you would do in this case is lower the horn amp input gain to where the horn amp is match to the woofer amp. (You will notice that all pro amp input knobs are labled in db and that allows you to calculate proper settings.)...That done, your horns can still reach full power, but they won't get ahead of the woofers as you change mixer master levels.