# Audio cable signal splitting

#### jack63ss

##### Member
WHAT is the correct way to split the signal from a wireless mic receiver so I can run it to 2 different amps ?

So the situation is this. I have a choral group of 50-100 for which I mic a piano that is in the pit in front of them with a speaker on the stage behind their risers. I currently use an old NADY wireless mic set and an old Pyne guitar amp/speaker, and it works reasonable well. My problem is they, picky people that they are, would like 2 speakers instead of just 1 in the center. So I bought 2 guitar practice amp/speakers (10amp), primarily because they were inexpensive and small. All 3 amp/speakers have a 1/4" input and an 1/4" output and individually work fine with the mic. Now the problem.
I though I could just string input-output-input, but turns out all 3 outputs are headphone, so they cut out when I plug a cable in. So we decided to just SPLIT the cable from the mic. Nope, got all kinds of noise. Which leads to my question. WHAT is the correct way to split the signal from a wireless mic receiver so I can run it to 2 different amps ? I am sure there is a way to do it, I just can't figure it out.

Thanks
Jack
ps I'm a lighting guy doing double duty, so please cut me as much slack as possible.

#### Amiers

##### Renting to Corporate One Fixture at a Time.
A console. Mic in to speaker outs.

Also a lighting guy no slack given 😜

#### FMEng

##### Well-Known Member
Fight Leukemia
This sounds like the classic unbalanced audio causing ground loops. What are the brands and models for the equipment?

#### microstar

##### Well-Known Member
One good approach might be to use an "audio distribution amplifier "(ADA) but it would likely cost more than your guitar amps.
But since you are laser-focused on cheap, you could get something like the Galaxy Audio JIBS which takes one input and has 4 outputs; you will only use 3 of the outputs in your scenario.
You MUST use 1/4" to 1/4" phone plug SHIELDED cables to connect everything. Do not use speaker cables (which are not shielded) or you will have massive hummm problems.

#### RonHebbard

##### Well-Known Member
@jack63ss RANE's Dennis Bohn's tech' notes when, and when NOT, to wye, or Y, could be a good read for you.
Toodleoo!
Ron Hebbard

#### FMEng

##### Well-Known Member
Fight Leukemia
With all due respect to the other responders, neither of those will address the root cause of the hum and buzz. Guitar amps are notorious for picking up noise, even when used for their intended purpose, due to the high input impedance and being unbalanced (1 conductor plus shield). Add in a couple of different AC grounds and long audio cables, and you have the perfect recipe for ground loop hum galor.

Without having any more equipment specifics, let me recommend the following:

Use the following transformer at the input of each guitar amp
https://www.sweetwater.com/store/detail/A85F--shure-a85f-line-matching-transformer

Assuming the Nady receiver has an XLR output, use a Hosa Y cable
https://www.sweetwater.com/store/detail/YXM121--hosa-yxm-121-y-cable-xlr3f-to-dual-xlr3m-6-inch

Both of those items are widely available. Then, use XLR F to XLR M cables to make the runs from the receiver to the guitar amps. For added insurance, use a ground lifter at the amp farthest from from the receiver.
https://www.sweetwater.com/store/search.php?s=hosa+ground+lift

The transformers and XLR cables make the interconnections balanced (2 conductor plus shield), which the proper way to do it.

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#### TimMc

##### Well-Known Member
Return the f'n guitar amps. Get your money back.

Buy or rent a pair JBL Eon 10s or 12s. Or any number of similar products from QSC, Alto (bargains, they usually are), RCF, Yamaha. If your wireless mic does not have a balanced XLR output, get a transformer as FM suggests, then go to the first Eon (or equal) and out of its loop to the other Eon.

#### Ben Stiegler

##### Well-Known Member
and much as I love the founder of Nady, who donates his mansion annually to a non-profit jazz group fundraiser I work with, its pretty likely that your Nady is in a now-prohibited freq band. Why are you messing with wireless at all? A wired XLR output mic on the piano is 100x more reliable. And ... putting the piano monitors behind the chorus is also suboptimal. look at how your ears are shaped. The pinnae (ok, pinnas) are evolved to catch sound from the front and sides - and reject the rear. You can run those speakers/amps at much lower level, with better high frequency transmission by placing them in front of the choral risers and tilting them up. If you are micing the choir, put the speakers directly behind your mics so they live in the cardiod rejection node of the mic.

Have fun - poke me if questions [email protected]

#### MNicolai

##### Well-Known Member
Fight Leukemia
Yeah....as others have said, you should not be using guitar amps for stage monitors. Guitar amps are purpose-built for a specific instrument. They are not intended to be stage monitors for other types of instruments or vocals, nor are they intended to be quiet in terms of hum/background noise. They are also not a flat, ideal representation of the signal coming into them. Guitar amps are actually built specifically to colorize the signal going into them, which is absolutely not what you want for a stage monitor application.

If you must use guitar amps, go with what @FMEng posted. That's the best way to isolate some of the noise. The ideal solution is to get actual stage monitors. For what you're doing, I prefer QSC K8's or K10's, or the equivalent models from EV, but you can certainly get by with less.

##### Custom Title
Fight Leukemia
Behringer makes decent powered multipurpose speakers if you're on a budget. I've used a couple of their models in school settings with success. Many of them will also give you an actual line output that you can then daisy chain them together from a single line source. The only time I've used a guitar amp as a monitor is for an actual guitar and we miked the amp for signal and pointed it at the guitarist so he could hear himself.

#### BCAP

##### Well-Known Member
When you absolutely have to split microphone or line signals and have no other choice to achieve the result, Radial Engineering makes a number of excellent microphone splitters and line level audio splitters. These devices usually have transformers in them, they are designed to do the job and they have ground lifts on them which is also a big help.

Some wireless mic receivers have 2 outputs and the ability to deliver either or both a line level output or a microphone level output. Such as certain Sennheiser or Shure series. I have in the past used simultaneously the XLR balanced out for PA system application and 1/4" out of a receiver for recording application. It can work well.

However as others have said in this thread there are a number of different, maybe better ways to fundamentally set up your rig. I agree with many of the other comments on the thread. If it were me trying to solve the issue you describe I would use a wired mic or mics on the piano (or possibly a piano pickup, if it's decent) into a small mixer board, send an aux from the mixer out to powered monitor speakers with line inputs and outputs and you could daisy chain them. That would be one way.

I walk into theater environments where people are using guitar amps as monitors, I understand it's an inexpensive and quick way to do things but I almost always replace them with monitors I provide, I use QSC K12 and K12.2. This way I can run balanced line cables to the monitors from the returns and the monitors are designed for more of a full frequency range.

#### jack63ss

##### Member
A console. Mic in to speaker outs.

Also a lighting guy no slack given
Sorry it took me quite a while to get back to this thread, as after our Spring performance I kind of forgot about it. Of course that was until now as we have another show coming up after Thanksgiving.

So, yes I used guitar amps as monitors as they are inexpensive. I should have mentioned that all this equipment was bought on my dime, so I have to be careful about how much I spend, lest I incur the wrath of bridezilla. And the setup I use for the piano mic needs to be simple given the constraints of the physical situation. There is no way to run the piano thru our console without running 2 cables about 150' from the console to the monitors and having people walking over the cables all the time. Originally we chose to use a mic wired to a Peavy guitar amp with an unshielded cable, and it worked okay. Not great but okay. Then we switched to wireless with using the same guitar amp (unshielded) and it was okay, but not quite as good. Then they asked for two speakers, so we tried two smaller cheaper guitar amps using unshielded cables and it did NOT work okay, and that is where we are today.

#### Ben Stiegler

##### Well-Known Member
huzzah to FMEng 's thinking. You don't need to be the audio martyr. Alternative approach - if they don't want to buy the equipment, rent it to them. Buying used and renting based on % of list price you'll be breaking even soon. I think 5-8% of list per day, with a 5 day = 1 full week discount is in the ballpark.

PS - in audio, its better to be the wolf than the sheep, by which I mean "they asked for 2 speakers". Put that aside - how many speakers do YOU think are needed to provide even (+/-3 db) coverage for the chorus? How wide does the choral riser or footprint span? For a 20' riser width, I'd be using 2 floor monitors at 1/3 and 2/3 width ... but by the time its 30', there would be 3 at 1/4, 1/2, 3/4. Etc. And that's without seeing your space, just a rough starting point.

#### jack63ss

##### Member
I've been working with this chorus over 35 years, normally doing lighting. And I never asked them for money as I want there to be no doubt who owned the equipment. And one point I also did lighting for a couple of theater groups, again mostly using my equipment. However, while I said I use my money, the guy that actually runs the sound board and I now both get an honorarium, and have been using that to buy equipment. We just this week spend a bunch buying 4 new wireless mics (most of our new stuff is Shure), so we were trying to do this on a low budget. However, just before I read this reply I was looking at the Mackies again and thought the same thing, they are too small.
So I think we are going to put this on hold until we have the money to buy better equipment, like the Behringer that FMeng mentioned. Thanks for all your feedback, and for putting up with me. This forum really does make a difference.
Thanks again,
Jack

#### Ben Stiegler

##### Well-Known Member
um, Behringer is crap-ola, in my experience. And besides the horrible warranty service situation, check out the lawsuit history between QSC and Berhringer. When B was getting started, they Bogarted a QSC RMX amplifier motherboard - so faithfully that the B version of it still had the QSC logo and part # on it. That's illegal in a lot of ways. But it served B's purposes - by the time Pat Quilter and QSC caught up to them in court, they had made a pile of  and gone on to other products.

I have had several B boards (before I learned the above) and they all failed in different ways - power supply blew out and took the mixer board on 1 of them, faders and channels started dying within 2 years on one used about 12 times a year in a HOW, etc. Saver your $and your karma - avoid Behringer. ------- More History ---------- Legal cases In June 1997, Mackie accused Behringer of trademark and trade dress infringement, and brought suit seeking$327M in damages[18][19] but such claims were later rejected by the court. In their suit, Mackie said that Behringer had a history of copying products by other manufacturers and selling them as their own.[20] The Mackie suit detailed an instance in which Behringer was sued by Aphex Systems for copying the Aural Exciter Type F—in that case Aphex Systems won 690,000 Deutsche Marks.[20] The Mackie suit also mentioned similar cases filed by BBE, dbx and Drawmer.[20] On November 30, 1999, the U.S. District Court in Seattle, Washington, dismissed Mackie claims that Behringer had infringed on Mackie copyrights with its MX 8000 mixer, noting that circuit board layout was not covered by U.S. copyright laws.[21][22]

In 2005, Roland Corporation sued to enforce Roland's trade dress, trademark, and other intellectual property rights with regard to Behringer's recently released guitar pedals.[23] The two companies came to a confidential settlement in 2006 after Behringer changed their designs.[24]

In 2009 Peavey Electronics Corp. filed two lawsuits against various companies under Behringer/Music Group umbrella for patent infringement, federal and common law trademark infringement, false designation of origin, trademark dilution and unfair competition.[25] In 2011 The Music Group filed a lawsuit against Peavey for "false advertising, false patent marking and unfair competition". Basically, the lawsuit was about Peavey also failing to comply with the same FCC regulations Behringer had troubles with, which was felt to create unfair competitive adavantage.[26]

#### Jay Ashworth

##### Well-Known Member
I cannot speak to their early behaviors, Ben. But I can tell you that the x32/m32 series, now with about 9 desks in it, has made it to rider-friendly, at least in lower tiers, and has a good enough warranty experience that it hasn't put them out of business in probably over a million boards by now. My first one, 7 years ago, is still going strong, and that's not unusual.

The Music-Group buyout/merger clearly did good things...

#### FMEng

##### Well-Known Member
Fight Leukemia
There are plenty of reasons to like or hate Behringer, but when the budget is tight there is not always a competitive product in the same price range. That seems to be the case for powered speakers. When I suggested the B208D, it was because there was nothing else for a little more money. I would rather own a QSC, Yamaha, or EV, but consider the OP's situation.

As for bad corporate behavior, I'd put Harmon right up there for buying up industry leaders and then killing most of their product development and any semblance of quality. Harmon hasn't touched a company that isn't far worse off for it. Surprisingly, the Samsung buyout does not seem to have changed anything.

#### jack63ss

##### Member
SOLUTION: So I managed to resolve my issue on using 2 inexpensive guitar amps to mic our piano by using BALANCED components. I bought a TRS splitter, and 2 TRS cables, plugged the splitter into a wireless receiver that has balanced 1/4" TRS output and everything worked fine. Sound quality is great, and people actually complained it was too loud, a first. Total cost \$25.67. And I learned a valuable lesson about balanced vs unbalanced and how much of a difference it can make. Thanks for all you help. Jack

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