Behind The Mixer

Learn Church Audio Artistry | Church Sound

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Top Three Common DI Box Problems and SolutionsHow many times has a line check problem been the results of a DI box issue?  DI boxes, while simple in functionality, do present the opportunity to cause problems.  Here are the three common line-check-related issues where the DI box is to blame;

  1. No sound coming through the channel.
    A DI box won’t pass sound through when the input cable is incorrectly plugged into an output jack.  An active DI box won’t pass sound through if there is no power.  Make sure that either the phantom power is on, or the active DI box has its AC adapter plugged in or it’s running on fresh batteries.
  2. The sound coming from the DI box is less than expected.
    Some DI boxes allow for control of the input signal strength or the output signal strength.  Check the settings on the DI box.  This could be a knob labeled “gain” or “volume.”  Some DI boxes have controls for both.  Also, you might have a pad switch enabled on the DI which drastically cuts the signal strength.  These can even exist on passive DI boxes.
  3. A hum can be heard through the channel with the DI box.
    Once you flip the ground lift switch, the noise goes away.  The ground lift switch is used to eliminate the hum caused when you have a grounding problem that’s made evident by a looped signal.  While you can use the ground-lift switch, consider it an indication that there is a problem in the sound system or with a component like an electric guitar.  Therefore, make note when this occurs and spend time looking for the source of the problem after the service.  It could be an electric guitar has a grounding problem or something else.  In the case of the guitar, if the guitarist touches the strings and the hum goes away, then the guitar has a grounding wire loose inside.

DI boxes are great little electrical signal transformers.  Most of the time, the issues you encounter will be caused with improper cabling or setting issues.  Don’t overlook them when reviewing your signal chain for the source of a problem.  They might be small, but they are mighty.

 Question: Have you ever had a DI box go out completely? 

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  1. Recently I tried splitting the mono output signals from 2 keyboards I use. The outputs are unbalanced.
    At both instruments’ output I used a splitter & connected directly to a powered mixer I use for monitoring.
    The other split ran through a passive Radial stereo DI (1 into left Thru & other Rt thru. When testing the PA mix there was no signal coming into the PA from the DI ?
    Let me preface this by saying the day before I tested all 4 output cables from the splitter into 4 separate inputs in my powered mixer & all worked. The only difference was I didn’t use the DI box in testing.

    Reply

  2. Hi Chris, I have been playing at church with Helix LT (no amp) just direct mono to FOH via Direct box. Recently they purchased Radial ProD2 stereo passive box so I can play in stereo rather than mono. Been using 1/4 out mono but when we tried two 1/4 audio cables (TRS) from Helix LT to the new Radial box, we have a low hum when I turn on Helix and this is with volume all the way down on Helix and guitar. From my research is appears to be impedance issue / ground loop? Our sound person says “their is noise in channel on board”..We did usual swapping cables around (didn’t work) and finally just used pad in -15db switches on front of the DI box, that seemed to help. Other guitarist are recommending that I go straight XLR out to FOH (no DI box) among other things. XLR’s out on Helix have a ground lift switch and I noticed the DI box does also … all ideas appreciated

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  3. Hi ….. am having some issue with my DI box , am still getting this hum sound from it when connected to my Backline for my bass guitar .. I have tried more then 2 product of DI but still getting that hum sound….. what do I do.

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  4. Hi, at our church we have two Behringer DI20 boxes (in addition to other DI boxes). They both seem to have the same issue, that a signal input to ch1 comes out of both XLR outputs, even thought the ‘link/2-ch’ switch is in the ‘2-ch’ position. What do you think is happening here? I have tried a spray of contact cleaner on the switches, but no change. Thanks, in advance!

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  5. We have monitor 1for the lead singer feeding back thru the keyboard amp. The amp is for the keyboard musician only. Amp then runs to DI box and from there to floor box and up to mixer.

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  6. Hi Chris,
    My DI box is not giving out any sound. Does that mean the DI box is dead??? As in completely busted. Because for around like two years plus, we’ve been using the same DI box and now it is not really giving out any sound. My DI box is very sensitive, when we moved it by accident the connection will cut and then we have to tamper with the sides and that is very annoying. So what should I do? Should I take it for repair or should I just get a new instead? What are your opinion Chris?

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  7. Hi Chris,
    I am running an acoustic ukulele (with active pickup) through a Boss, acoustic singer VE-8. Actually, I don’t use the vocal part of the box, just the instrument part, and I like it. Then I run the VE-8 through an external mixer and then to a Yamaha Stage Pass portable sound system. It has worked well but lately, I have been getting a noticeable hissing sound through my speakers and I’ve traced it back to the boss stomp box. Any thoughts?

    Reply

    • Check the output controls on the pedal and see if they are higher than normal. Curiously if it’s just line noise that seems louder because it was turned up. Also, toss in new batteries if it needs them – eliminate the simple stuff.

      Reply

  8. Hello I want to buy a dbx db12 di box but my problem is db12 only uses phantom power from the mixer and my mic is audix om5. Audix om5 does not require phantom power so if i switch on the phantom power of my mixer I am worried with my mic that it may damage after a long use with phantom power. Thank you for your help.

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  9. We use passive DI boxes for our keyboard and accoustical guitars and have 4 of them fail over a couple of years.
    Looking inside there is not much to them. What is the usual failure cause? They will not pass a signal. Wiring was correct and replacing the DI solved the problem. All components look intact and
    no visual damage. Have not put a VOM on them yet.
    I am familiar enought with electronicsto be dangerous.

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  10. Hi,

    Good post here, however, I’ve got something a little perplexing going on which I was hoping you’d be able to advise me about.

    I always use a DI box for my acoustic and it works great. We have the phantom power on the desk on. My guitar is passive.

    Here’s the thing though – last night another acoustic guitar player joined us for practice and she has an active acoustic, which we also ran through a DI which is obviously also powered by phantom power.

    Her guitar sounded so distorted that it was almost like she was running through a distortion pedal or something? We tried changing the battery in her guitar but it didn’t help. Am I missing something here?

    Any help would be greatly appreciated!

    All the best,
    Sean

    Reply

    • Your guitar pickup is not powered and therefore needs phantom power. This is why there are acoustic-specific powered DI’s like the LR Bagg’s Para DI. Her guitar pickup is powered via battery and therefore she doesn’t need phantom power. That’s why it distorted – too much power so an overdriven signal. had you turned off the phantom power, it would have sounded good.

      Here’s a bit more on DIs.
      https://www.behindthemixer.com/passive-and-active-direct-boxes-how-they-should-be-used/

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      • Thanks very much Chris – on Sunday I will drive my DI with a 9v battery and turn the phantom power off on the desk. Thanks again for your help I’ll give that article a read too.

        Take care,
        Sean

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      • BTW, just had a look at that article you suggested, which helps me understand what DIs are for in the first place (LOL) – should we be running our keyboard through a DI too?

        Thanks again,
        Sean

        Reply

        • Any time an unbalanced (instrument) cable runs more than 10-15 feet, you need to run it into a DI so you get to a balanced cable. Balanced lines can run a few hundred feet without signal degradation or interference problems. Unbalanced cables can’t do that.

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  11. Great artice! I often run into the opposite variation of #2 with the sound coming from a DI box being distorted. On an active DI with pads this usually means I need to engage a pad to avoid clipping in the DI.

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  12. Hi, we are going to buy di’s in my church very soon, we have some very old and bad quality DI’s right now ($30 and cheaper) so i was thinking in Radial Engineering JDI MK3 Passive Direct Box for the bass, LR Baggs Para Acoustic for acoustic and Radial Engineering ProDI Passive Direct Box for anything else.
    Is this a good selection?
    Is this change going to make our instrument’s sound get better?
    Can someone recomend something?

    Thanxs

    Reply

    • Andrés, before you jump in on the LR baggs (which I personally love), know that it’s a tool that your acoustic guitar player will need to learn to use. You could set it for them but it’s probably something they will want to learn at some point. My guess is that if you told them they were getting one to use, that they would send you a thank you card, take you our for dinner, wash your car, etc. :)

      Will the other DI’s make all your instruments sound better? Most likely. A while back, I surveyed sound tech’s and musicians on which DI’s they have used and their experiences. You can see the survey results here.

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      • Thanks a lot.
        We always try to teach each musician what they’re using, how the sound works, etc, its like a rule in my team.

        And thanks for the link, its very useful xD

        BTW we started using presonus ipod/iphone app (qmix) the past weekend and it’s so cool, i mean…wireless monitor mix control for free, you have to make a post about it. :)

        Thanks a lot again.

        Reply

  13. We had a DI problem where the acoustic guitar sounded as if it was using a distortion pedal…not real heavy but enough to sound off. Turns out, the battery in the DI was almost dead. We replaced the battery and all sounded good.

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  14. yes I had!

    I ran into some Behringer Active Boxes. Dirt cheap, dirt quality.

    I use dbx db12 active boxes. Built like a rock, good quality. I recommend them to everyone looking for DI boxes.

    Reply