In this test, I am trying to determine if using a Radial JDI Passive Direct Box makes any difference in my usual live performance set up. A DI (direct box) is usually used to turn an unbalanced signal into a balanced signal and is commonly found where long cable runs are necessary (snakes on big stages, for example) to get the signal from the instrument to the mixing board.

I stand right next to my mixer when I play so long cable runs are not a part of my set up. I wanted a DI for times when I might be playing on other stages, through house systems and I figured I may as well get a good one. The Radial JDI is considered by many to be one of the best passive direct boxes on the market. So my question is, does it make any difference if I’m setting up my sound system and standing right next to the mixer?

Room: I recorded these samples in our living room. It is 16’ 5” x 13’ 5” with carpet. Nothing fancy.

Guitars: I used two different guitars and recorded two samples with each, one with the DI and another without. Both guitars are Cole Clark Fat Lady 2s. The first guitar has a bunya top with bunya back and sides and does not have a cutaway (on the left.) The second guitar has a bunya top, blackwood back and sides, a cutaway and the optional 3rd body sensor pickup (on the right.)

Sound System: Bose L1 Model 2 with T1 Tone Match Engine and 1 B1 (sub.)

Cables: I used a 15’ Planet Waves Circuit Breaker cable from the guitar either to the DI or directly to the Bose T1. When the JDI was in the chain I used a 12” Monster Cable XLR to connect the JDI to the Bose T1.

Recorder: I used a Zoom H2 handheld recorder mounted on a mic stand 5’ high and 8’ from the Bose L1.

Recording Process: I dumped each recording into GarageBand, cleaned up the beginning and the end and sent them to iTunes. No EQ or any other kind of adjustments were made to the recording.

Bose T1 Settings: I used the Acoustic Guitar, Steel String w/Piezo preset EQ for both guitars. These guitars are quite different so I made some EQ adjustments on the T1 for each guitar but left the EQ exactly the same for the two samples. I had the channel volume at 12 o’clock and the T1 Master volume at just a hair past 10 o’clock. I also used the PARA EQ on the T1 to take a -7.0 db cut at 440 Hz with a Width of 2.03. I did this for both guitars and all recordings. I do this with just about every acoustic guitar I run through the L1, Model 2.

Note: I did need to adjust the trim settings when I took the JDI out of the chain. With the JDI I had my trim set at about 4 o’clock. When I removed the JDI and plugged straight into the T1 I was peaking the channel so I backed the trim down to just shy of 3 o’clock.

Samples: Just click on the title of the sample and it will open up and play in a new window. The samples are best heard with headphones.

1. Cole Clark FL2A Bunya/Bunya	Cole Clark FL2AC Bunya/Blackwood
   Cole Clark FL2A Bunya/Bunya w/Radial JDI.mp3	Cole Clark FL2AC Bunya/Blackwood w/Radial JDI.mp3
   Cole Clark FL2A Bunya/Bunya No DI.mp3	Cole Clark FL2AC Bunya/Blackwood No DI.mp3

Conclusion: I’ve gone back and forth between the samples many times, both through my studio speakers and with my headphones. I’m not noticing much of a difference at all. I think any difference I might be hearing is only because I know which sample I’m clicking on. There are times when I think the samples with the JDI sound a bit cleaner and a bit more lively but then the next time I listen, I hear no difference. If there is a difference, I think it is subtle enough that I don’t need to have the JDI in my signal chain when I am playing live through my Bose. I will certainly keep it in my bag and use it when I’m playing through other sound systems but for now, I think I can go without it when using my Bose.

© 2009 Matt Wahl