www.radialeng.com True to the Music Radial Engineering Ltd. • 1588 Kebet Way, Port Coquitlam BC V3C 5M5 Tel: 604-942-1001 • Fax: 604-942-1010 • email: info@radialeng.
STEREO PASSIVE DIRECT BOX USER GUIDE Table of Contents Page Overview and DI basics................................................................................................................... 1 Features and functions.................................................................................................................... 2 Making connections and quick start................................................................................................ 3 Stereo and mono keyboard............
® True to the Music Passive DI basics A direct box has the primary role of converting an unbalanced high-impedance signal to a balanced low impedance signal. Unbalanced signals typically ‘max out’ at around 8 meters (25’) before noise begins to be audible. Balancing the signal allows distances of 100 meters (300’) or more without noise.
® True to the Music Features & Functions 1. SUM MONO: Converts the channel IN and THRU jacks into left and right inputs and passively mixes them to mono. 2. -15dB PAD: Reduces the input sensitivity by -15dB to prevent distortion. 3. 180° POL: Inverts signal polarity at the XLR output by toggling pins two and three. 4. GROUND LIFT: Disconnects pin-1 at the XLR output to reduce noise caused by ground loops. 5. XLR SEL: Activates the +4dB XLR line input and disconnects the ¼", RCA and 3.5mm input jacks. 6.
® True to the Music MaKinG cOnnectiOns Before making connections, ensure all signal levels are turned down or equipment is shut off. This will help eliminate turn-on or plug-in transients that could cause damage to more sensitive equipment such as tweeters. QuicK start: The Radial Duplex is a passive direct box and does not require any external power such as phantom or batteries. Follow these steps for each channel. 1.
® True to the Music stereo or mono keyboard The Duplex features ¼" InPUT and THRU jacks for each channel allowing you to patch the instrument signal through to a personal monitor system. The XLR outputs connect to the Pa or recording system. You can connect a stereo keyboard by simply doubling up the connection using channel-2.
® True to the Music Keyboard and drum machine Engaging the Mono sUM also makes it possible to connect a stereo device to one channel and have the Duplex mix it down and deliver a mono signal to the Pa system. Used this way you can connect one or two stereo devices in mono. The balanced XLR outputs connect back to the Pa or recording system. STEREO SAMPLER connecting consumer audio devices Today, laptop computers and tablets have become part of most audio shows and DJ setups.
® True to the Music using the rca jacks The Duplex features RCa InPUT and THRU jacks for each channel allowing you to patch in to a personal monitor system. You can also use the Mono sUM switch to connect one or two stereo devices in either mono or stereo depending on how you choose to patch it. as described earlier, the balanced XLR outputs connect to the Pa or recording system (not shown in the diagrams).
® True to the Music connecting balanced sources You may run into a situation where you need to take a +4dB balanced line-level source and convert it to a mic-level. This is particularly important in snake systems where the signal path is optimized for a microphone between -40dB and -20dB. If one were to connect a +4dB signal, the mic splitting transformers would likely overload and crosstalk would likely be introduced due to the +4dB line-level signal being significantly louder than the mic-level signal.
® True to the Music Removable Switch caps When using the Duplex on a run of shows, it may be preferable to set the switches at the beginning of rehearsals and then remove the switch caps to prevent the functions from being accidentally switched by stagehands. conflict with the sound of the PA system and room acoustics creating a hot spot that is prone to feedback. Reversing the polarity can often move the problem out of the way without having to resort to excessive EQ’ing.
® True to the Music Block Diagram Specifications Audio circuit type: .......................................... Passive, transformer based ¼" Number of channels:................................................Dual channel (stereo) Frequency response: ............................................ 20Hz ~ 20KHz (± 2dB) RCA CH-1 INPUT MERGE CH-1 THRU RCA -15dB PAD POLARITY 180º XLR-IN Switch CH-1 XLR Line In ¼" Dynamic range: ........................................................................
RaDIaL EngInEERIng LTD. (“Radial”) warrants this product to be free from defects in material and workmanship and will remedy any such defects free of charge according to the terms of this warranty. Radial will repair or replace (at its option) any defective component(s) of this product (excluding finish and wear and tear on components under normal use) for a period of three (3) years from the original date of purchase.
