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3.5mm to 1/4" Distortion

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3.5mm to 1/4" Distortion

Postby steakandlemonade » Thu Mar 23, 2017 4:11 am

Hello,

Live audio newbie here so please bear with me. I hope the question is relatively simple for you all to answer/point me in the right direction with. I'd very much appreciate it.

I have a Behringer Xenyx 1202 mixer. I have historically used 3.5mm to RCAs (with L/R 1/4 adapters) to plug in iPod, iPad, and Surface Pro 3 without any problems into the 5/6, 7/8, 9/10, 11/12 inputs. I receive clean, clear sound.

Image

In the hopes to "clean up" my board, I bought three "Stereo Intercomnnect 3.5mm TRS to 1/4 in TRS" from Hosa. My objective was to instead of having a bunch RCA's with adapters going the lefts and rights, I would have a single 1/4 into the balanced input(s) and have my Surface Pro going into the Mic 4 input, allowing me the ability to change the EQ's for such. Unfortunately, when using these new Hosa 3.5mm TRS to 1/4 TRS in any of the inputs, I am loosing a ton of quality and the sound is very distorted and is certainly not clear.

What did I do wrong? What do I need to buy to fix this problem?

Thank you very much for the help.
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Re: 3.5mm to 1/4" Distortion

Postby Hugh Robjohns » Thu Mar 23, 2017 10:56 am

You have fallen into the classic 'stereo unbalanced output into a mono balanced input' trap!

You're not the first and won't be the last -- it's a very common mistake.

The output from the iPod or whatever on a 3.5mm TRS plug carries the left channel on the tip, the right channel on the ring, and a shared common ground reference on the sleeve.

If the cable has a single TRS plug at the end then those same signals will appear on the same parts of the larger A-type plug.

However, the TRS input sockets on the mixer are designed to take a balanced signal, with the 'hot' side on the tip, cold on the ring, and cable screen on the sleeve. A balanced input is a differential input which means it looks for the difference between the signals carried on the hot and cold connections.

If the stereo unbalanced signal you're sending has a lot of central components (vocals, kick drums etc) they are the same on both sides, so the differential input will effectively erase them from the output, and you'll be left just with what is panned out to the sides of the stereo image -- so lots of reverb and maybe some backing instruments!

The cable you actually require to make this work as you want is 3.5mm TRS to TWO mono TS jack plugs.

Image

That kind of cable takes the left signal from the tip of the TRS and sends it to the tip of one of the quarter-inch plugs, while the right signal from the ring gets sent to the tip of the second quarter-inch jack plug. In that way, you have two unbalanced mono connections to plug into your desk (left/right), and all will be well...

Hope that helps

H
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Re: 3.5mm to 1/4" Distortion

Postby shufflebeat » Thu Mar 23, 2017 11:02 am

Hugh Robjohns wrote:You have fallen into the classic 'stereo unbalanced output into a mono balanced input' trap!

H

I sincerely hope you were wearing a tweed Trilby hat (with optional comedy sideburns) and preparing a vintage briar pipe when you wrote that.

+1, BTW.
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Re: 3.5mm to 1/4" Distortion

Postby MarkPAman » Thu Mar 23, 2017 12:47 pm

Hugh Robjohns wrote:You're not the first and won't be the last -- it's a very common mistake.

Indeed it is.
May I suggest a sticky for this.
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Re: 3.5mm to 1/4" Distortion

Postby steakandlemonade » Thu Mar 23, 2017 3:40 pm

Hugh,

Thank you very much for answering my question.

After watching some YouTube videos about understanding unbalanced/balanced audio and I was afraid that was the issue. I'm still learning all the simple stuff!

Thanks for clarifying for me and helping out a newbie.

Best,
-steakandlemonade-
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Re: 3.5mm to 1/4" Distortion

Postby Wonks » Thu Mar 23, 2017 7:45 pm

We've all got to start somewhere. Asking and learning is all part of the process. Not asking the question is what gets you into trouble.
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Re: 3.5mm to 1/4" Distortion

Postby Dave B » Thu Mar 23, 2017 9:18 pm

(sigh) all right then ..... where DO babies come from .... ?
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Re: 3.5mm to 1/4" Distortion

Postby Hugh Robjohns » Thu Mar 23, 2017 9:23 pm

:D
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Re: 3.5mm to 1/4" Distortion

Postby Guest271017 » Thu Mar 23, 2017 9:25 pm

Put on an engineer's cap and just slightly un-plug the 1/4" jack until tip and ring are engaged on the tip lead inside the plug. The original stereo to mono contraption. :mrgreen:


The above is a joke.
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Re: 3.5mm to 1/4" Distortion

Postby Scramble » Thu Mar 23, 2017 9:35 pm

An entirely forgivable mistake.

But misspelling 'losing' as 'loosing' isn't forgivable. For that the Spanish Inquisition will have to come out with the comfy chairs ands the soft cushions!
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Re: 3.5mm to 1/4" Distortion

Postby Martin Walker » Thu Mar 23, 2017 10:03 pm

shufflebeat wrote:
Hugh Robjohns wrote:You have fallen into the classic 'stereo unbalanced output into a mono balanced input' trap!

I sincerely hope you were wearing a tweed Trilby hat (with optional comedy sideburns) and preparing a vintage briar pipe when you wrote that.

:bouncy: :clap: :thumbup:

By the way, a warm welcome to steakandlemonade on the SOS Forums! 8-)


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Re: 3.5mm to 1/4" Distortion

Postby sri ram » Tue May 29, 2018 1:26 pm

Hello guys a balanced input?

I am stuck in b/w buying jbl lsr305 and mackie mr624.
I am going to buy only a single monitor and use it as a mono due to cost concerns and space in my bedroom. I have setup voice meeter software to send out mono output through the line output from my Asus H270F gaming motherboard. The jbl has only balanced input and mackie has both balanced and unbalanced inputs. So I don't understand which cable to use.
I have just ordered a 1/4 inch stereo to 3.5mm cable from aliexpress (Ugreen 3.5mm to 6.5mm Stereo Audio Cable).
So is it fine to send mono output from my motherboard through a 1/4 inch stereo cable to those monitors and especially the jbl which has got only a balanced input?
Also will I get enough volume to fill my small (9W*7.5L ish) room. I am only going to use it as a desktop monitor.
Thanks for your help and sorry for my bad english.
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Re: 3.5mm to 1/4" Distortion

Postby Sam Spoons » Tue May 29, 2018 8:32 pm

Scramble wrote:An entirely forgivable mistake.

But misspelling 'losing' as 'loosing' isn't forgivable. For that the Spanish Inquisition will have to come out with the comfy chairs ands the soft cushions!

Unless you're talking about arrows when either spelling is appropriate (though to convey different meanings) :headbang:
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Re: 3.5mm to 1/4" Distortion

Postby Sam Spoons » Tue May 29, 2018 8:34 pm

sri ram wrote:Hello guys a balanced input?

I am stuck in b/w buying jbl lsr305 and mackie mr624.
I am going to buy only a single monitor and use it as a mono due to cost concerns and space in my bedroom. I have setup voice meeter software to send out mono output through the line output from my Asus H270F gaming motherboard. The jbl has only balanced input and mackie has both balanced and unbalanced inputs. So I don't understand which cable to use.
I have just ordered a 1/4 inch stereo to 3.5mm cable from aliexpress (Ugreen 3.5mm to 6.5mm Stereo Audio Cable).
So is it fine to send mono output from my motherboard through a 1/4 inch stereo cable to those monitors and especially the jbl which has got only a balanced input?
Also will I get enough volume to fill my small (9W*7.5L ish) room. I am only going to use it as a desktop monitor.
Thanks for your help and sorry for my bad english.

Used in the near field as a desktop monitor that JBL will give you plenty of volume. Use standard unbalanced jack input to the speaker and you'll be fine too.
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Re: 3.5mm to 1/4" Distortion

Postby Hugh Robjohns » Thu May 31, 2018 10:02 am

sri ram wrote:So I don't understand which cable to use. I have just ordered a 1/4 inch stereo to 3.5mm cable from aliexpress (Ugreen 3.5mm to 6.5mm Stereo Audio Cable).
So is it fine to send mono output from my motherboard through a 1/4 inch stereo cable to those monitors and especially the jbl which has got only a balanced input?

You're not alone in your confusion, but sadly that cable won't do it for you.

If you're sending mono from your computer you will have exactly the same signal on both the left (tip) and right (ring) contacts of the 3.5mm plug because the computer provides an unbalanced stereo output.

The terminals of the 3.5mm plug will be wired directly to the corresponding terminals of the quarter-inch 'stereo' plug, but you are going to plug it into a balanced input which is only interested in the difference between signals presented on its hot (tip) and cold (ring) contacts. A balanced input is a differential input -- it only 'hears' the difference between the two signal wires, and completely ignores anything the same!

As a result, using this cable, you will not hear anything at all (or only a very weak low-level signal).

Instead, you need a cable that has a stereo 3.5mm plug at one end, and a MONO quarter-inch plug at the other. The left and right channels from the 3.5mm end will be connected together and wired to the hot contact of the quarter-inch plug, while the cold contact will be grounded through the extended shaft (sleeve) of the plug, which will work as hoped.

H
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