Which cables to use for KRK and Focusrite

Hello forum.

I'm a newbie with studio gear, and want to connect balanced cables into my focusrite audio interface. My current PC build for some reason is making the Studio monitors make a static and hissing sound, so I saw on YT people recommending to try Balanced cables. The only problem is when I saw my Audio interface it doesn't have the balanced Cable option. So I'm trying to understand what cables I need to go for the balanced option. I have included what gear I have and what I believe is the right cable connection to be confirmed before I purchase them online.

Hope there's a solution, thanks forum.
 

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CrowsofFritz

Flamingo!
Not possible. You can’t make an unbalanced signal balanced. The only option you have is to get a better interface. Buuuut, there’s no guarantee that it’ll solve the hiss. I have balanced connections and have hiss on my monitors. It’s just inherent in the monitors as well as noise being introduced from a multitude of factors outside just the cables and connections. A DI box actually really helped reduce the noise, but there’s still some left. I don’t really mind it. It’s very quiet hiss, and doesn’t impact my ability to work in any way.
 
Thanks for your reply. I was watching some more YT videos on monitor and interface set up. So wouldn't these cables which have the XLR cable (male) connect into the XLR (female) where it indicates its the Balanced section of the Monitor, and the RCA parts of the cables go into the interface? Are these not the right type of cables?

I just bought the interface since I found it on Christmas special, I should have invested to buy a better interface as you specified.

Worse case scenario, I'll try a DI Box and see if the noise goes away.
 

ecc83

Well-known member
Thanks for your reply. I was watching some more YT videos on monitor and interface set up. So wouldn't these cables which have the XLR cable (male) connect into the XLR (female) where it indicates its the Balanced section of the Monitor, and the RCA parts of the cables go into the interface? Are these not the right type of cables?

I just bought the interface since I found it on Christmas special, I should have invested to buy a better interface as you specified.

Worse case scenario, I'll try a DI Box and see if the noise goes away.
You certainly can make an unbalanced signal balanced! People do it all the time*. There are several options. Simplest one for the newb is a pair of 1:1 transformers (means a ratio of unity, no step up or down) The Art Cleanbox two is very well thought of but you can buy a very cheap twin transformer unit off Azn which is actually not bad and will break any 'ground' loop if that is your problem and that is quite possible since I see those monitors have a mains earth, 3pole IEC socket. I shall find you a link shortly.

Another method is to 'impedance' balance the outputs but since that involves some soldering and a VERY tiny bit of electronics I shall leave that there as FYI. Even more complex but technically the best solution is *. (if you CAN do some soldering and wire surgery do tell!)

You do NOT want to get a "DI Box". As these things are generally considered, they use a high, 10: 1 transformer to deliver a balanced, mic level signal and even very high quality high ratio transformers can alter a signal audibly.

Yes, you would have been better advised and got a more expensive interface but if swapping it is a problem, hang in there and let us sort the problems? There is no guarantee that a $1000 AI would not cause some form of noise issue. Look upon this all as a learning experience and save up for better. (I cannot recommend the MOTU M4 TOO highly!)

*A few weeks ago I built a high grade electronic balance box to drive my Tannoy 5As but that would be a little beyond most folk. The build is in the DIY section.


That's the chap. Initially just plug it into the AI's RCA outs and the speakers. That will eliminate any ground loop issues. If you find the transformers cause some changes of the sound you will need to buy better but maybe, live with it for now and save pennies? Ifm as is likely, the sound is fine you can then buy or make RCA to XLR balanced cables and have a balanced feed to the speakers.

Dave (oil be bek!)
 
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CrowsofFritz

Flamingo!
Thanks for your reply. I was watching some more YT videos on monitor and interface set up. So wouldn't these cables which have the XLR cable (male) connect into the XLR (female) where it indicates its the Balanced section of the Monitor, and the RCA parts of the cables go into the interface? Are these not the right type of cables?

I just bought the interface since I found it on Christmas special, I should have invested to buy a better interface as you specified.

Worse case scenario, I'll try a DI Box and see if the noise goes away.
I wasn’t recommending the DI box to you. That was just my set up as I need to use its ground lift function, which is probably not applicable to you.
 

rob aylestone

Well-known member
At line level - I really doubt you'd hear any difference between balanced and unbalanced connections and loads of people work on an RCA output to their speakers. Hiss? You mean a constant unchanging hiss, but crackles? As in a loud nasty broken cable type crackle, or a more electronic crackly sound? or a buzzy crackle? This is often a problem with the driving computer putting noise onto the interface's ground. Disconnect the interface from the computer. Does the hiss and crackle carry on? This indicates the issue is between the interface and your speakers. If removing the computer makes no difference - then you know where to look. Disconnect the link to the speakers and add headphones? Still got hiss and crackles? You need a systematic connect/disconnect each piece to track down the source here. I doubt it's cables.
 

ecc83

Well-known member
At line level - I really doubt you'd hear any difference between balanced and unbalanced connections and loads of people work on an RCA output to their speakers. Hiss? You mean a constant unchanging hiss, but crackles? As in a loud nasty broken cable type crackle, or a more electronic crackly sound? or a buzzy crackle? This is often a problem with the driving computer putting noise onto the interface's ground. Disconnect the interface from the computer. Does the hiss and crackle carry on? This indicates the issue is between the interface and your speakers. If removing the computer makes no difference - then you know where to look. Disconnect the link to the speakers and add headphones? Still got hiss and crackles? You need a systematic connect/disconnect each piece to track down the source here. I doubt it's cables.
I agree Rob, I was really answering the OP's original question and countering the point that unbalanced sources cannot be balanced. As I pointed out, they can of course with varying levels of complexity and cost. What is not easy to do is make a Ubal input balanced. You either need good quality "10k 10k bridging" transformers or some electronics.

I tend to suggest peeps buy that dual transformer unit because it has pretty good performance (at -10dBV levels) low cost and is a very useful 'diagnostic' tool.

Dave.
 

ecc83

Well-known member
Sure, but isnt that a different use case? Won’t any interference you get from an unbalanced connection still be present even after it’s turned balanced?
Quite possibly but these things are a 'process'. The $10ish transformers I linked to are a quick and not very dirty solution to two problems. The OP gets balanced* outs from the AI as requested and the earth path is broken eliminating another possible source of the noise.
There is the other possibility that those KRK monitors have rather high 'self noise'? The review of them I found did not mention that but then they are budget monitors and he might have thought they were about "as good as one expects at the price"? Quite a few active monitors have (unforgivably IMHO!) audible hiss at the nearfield position of not much over a mtr and the younger folk might be bothered by this.

*Although not balanced until properly wired cables are used.

Dave.
 
At line level - I really doubt you'd hear any difference between balanced and unbalanced connections and loads of people work on an RCA output to their speakers. Hiss? You mean a constant unchanging hiss, but crackles? As in a loud nasty broken cable type crackle, or a more electronic crackly sound? or a buzzy crackle? This is often a problem with the driving computer putting noise onto the interface's ground. Disconnect the interface from the computer. Does the hiss and crackle carry on? This indicates the issue is between the interface and your speakers. If removing the computer makes no difference - then you know where to look. Disconnect the link to the speakers and add headphones? Still got hiss and crackles? You need a systematic connect/disconnect each piece to track down the source here. I doubt it's cables.
When the AI is connected, I can hear a soft crackling and hissing sound. When I disconnect the AI cable, just hiss sound. Here's what I can hear when the sound monitors are on.
 

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I also saw this option here:


has anyone tested a device like this before?

And also this one here:


I'm confused one says its a ground isolator, and the other one says its a noise filter.
 
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ecc83

Well-known member
Those USB isolator/filters are pretty expensive and I doubt they will fix your hiss and crackle problem. Is the crackle the same on both outputs? If not there is a very good chance that it is the interface that is faulty. I also 'think' I can detect some hum?

Please! Can you attach the sound again as a Bog s MP3 at 320k? I can hear that clip but cannot open it in anything that will convert it to .wav for further investigation, at least not quickly. I also see little point in compressing such a small file? Just adds complications this end!

Dave.
 
The sound crackle is on both outputs.

I tested the same audio interface with the studio monitors on an older PC and its fine, just this new PC which arrived a few weeks ago seems to be problematic with the AI and studio monitors.

Here's the sound in MP3 320
 

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arcaxis

Well-known member
If you haven't already done so, try different USB ports on the new PC. Not sure if it's still so, but USB 3.0 ports sometimes could cause issues in the past.
 
If you haven't already done so, try different USB ports on the new PC. Not sure if it's still so, but USB 3.0 ports sometimes could cause issues in the past.

Very true that! The USB 3.0 when I was plugging them into the motherboard ports, or the PC case ports, they'd make the mouse freeze. But the USB 2.0 no problem. So what I did was bought a USB hub to plug in any type of USB and haven't had any issue again. I'll try what you said plugging the AI USB cord into another port.
 

rob aylestone

Well-known member
That is data bus noise - the data sounds like that inside the computer and is leaking onto the screen or even the data conductors of the USB connection to the device. Sometimes you can reduce this with a big ferrite ring you wind the cable through - but sadly it's not a real crackle - just the data. Another computer might work better or worse - prove it with a borrowed one maybe?

Removing this kind of noise is rather random. One of my old interfaces I gave to a friend and it did this, but louder. Totally silent on my computer. In the end, he bought a new computer and it went away. He gave his old computer to his son who bought a cheap Behringher interface and that didn't do it at all!
 
That is data bus noise - the data sounds like that inside the computer and is leaking onto the screen or even the data conductors of the USB connection to the device. Sometimes you can reduce this with a big ferrite ring you wind the cable through - but sadly it's not a real crackle - just the data. Another computer might work better or worse - prove it with a borrowed one maybe?

Removing this kind of noise is rather random. One of my old interfaces I gave to a friend and it did this, but louder. Totally silent on my computer. In the end, he bought a new computer and it went away. He gave his old computer to his son who bought a cheap Behringher interface and that didn't do it at all!
my old PC with the AI and monitors connected did not do this, I tried it today. Jus the new PC once I connected it started.
 

ecc83

Well-known member
Stefan, you mentioned a hub? Do not try to run an interface from a hub in fact, as USB ports generally come in pairs, plug the interface into a pair 'on its own' i.e. do not use the other port of the pair for anything else (the occasional use of the port for a USB stick will probably be ok)

Dave.
 
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