Preface The following has been a labor of love for me. Love of the subject (low frequency reproduction in multi-channel audio systems in the home), and love for Mark Schifter, his vision and watching him realize that vision from the sidelines (though anyone who meets him never feels like a mere spectator).
Subwoofer Setup Tips And Procedures Tools Required: 1. Radio Shack SPL Meter. Can be obtained at Radioshack: a. Analog version: http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&product%5Fid=3 3-4050 b. Digital version: http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&product%5Fid=3 3-2055 2. 1/12 Octave Sine Wave Test Tone CD. You can generate your own tones or download some tones that have already been generated for you: http://www.nch.com.au/tonegen/ http://www.snapbug.ws/sinewaves/...
Terms: 1. LFE: Low Frequency Effects, AKA: Low Frequency Enhancement, AKA: The .1 channel. 2. Redirected Bass: This is all information contained in all 5 satellite channels that is below 80 Hz., which is redirected to the SW (subwoofer) output of the Pre/Pro or Receiver. 3.
Page 6
Overview: The goal in adding a subwoofer to any multi-channel audio system is to achieve as flat a frequency response curve as possible, in your particular room, with your particular system, through the crossover region and to as low as your subwoofer will allow. This is not to say that there is no room for adjustment from this point to allow for personal taste.
STEP #1: POLARITY TEST 1. Set your subwoofer near either the front left or the front right satellite. 2. Set your RS meter at the listening position (ear high) when seated. 3. Set the Phase Control of your sub to 0 degrees. 4.
STEP #3: PLACEMENT The goal here is to find the placement spot that offers the smoothest frequency response (not necessarily the loudest) in your room. NOTE: Placement also includes the placement of you yourself, in the room. Avoid a primary listening position that is in the center of the room and that is up against any wall in the room.
Step 3 continued: You can tweak the placement from there and see if you can improve your response graph before moving on to the next step. NOTE: Use caution when playing sine wave test tones through your subwoofer. They can damage your subwoofer by overheating the driver's voice coil if the volume is too high.
STEP #5: RELATIVE PHASE ADJUSTMENT Since the polarity is already properly set from step #1, it's time to fine-tune the relative phase between the satellites and subwoofer. NOTE: We will assume that the phase control is set at 0 degrees for this description. If it's set at 180 degrees, just work backward from 180 toward 0 instead of from 0 toward 180.
STEP #6: FINAL LEVEL ADJUSTMENT One last time, adjust the subwoofer level to the mains exactly as described in step #4 above. Now, use your Pre/Pro or Receiver pink noise level calibration tones or one of the calibration discs, if that's what you use, to lastly check the levels of all speakers and subwoofer. There have been many comments about how the RS meter is not accurate in the low frequency region, and is also said to differ from meter to meter.
Advanced Setup Section PARAMETRIC EQUALIZATION It is currently popular to use this tool to flatten peaks in subwoofer response that are caused by the room's interaction with bass sound waves. I am not a fan of this idea (nor have I ever been).
DUAL SUBWOOFERS -- MONO CONFIGURATION Now it gets interesting. Dual subwoofers afford several options that a single subwoofer can't. Let's explore them... NOTE: A quick word about bass in multi-channel audio systems, in general: When your satellites are set to 'small' and subwoofer to 'yes', the Pre/Pro or Receiver sums the LFE channel with the redirected bass from the satellites that are set to 'small' and sends that single, summed bass signal to the subwoofer(s) through the SW (subwoofer) output.
followed. You'll lose 3 dB or so of output vs. stacked subwoofers, and possibly more overall output vs. a corner placement as the sacrifice for better sounding bass, in my definite opinion. NOTE: In my opinion, whenever 2 or more subwoofers are used, regardless of placement configuration, they should ALWAYS be placed with every effort to achieving equidistance to the listening position with the main satellite speakers.
PLACEMENT You can try symmetric placement, keeping each subwoofer as close to the mains as possible. In fact, I believe that best results will be realized only if the subwoofers are the exact distance from the listening position as the main speakers. You can also achieve equidistance placement using an asymmetric placement of the 2 subwoofers if you measure as outlined above, in some rooms.
CONNECTIONS: 1. Set all satellites to 'large' and subwoofer to 'yes' in your player's speaker setup menu. 2. Run a cable from the player's analog SW output to subwoofer #1. This is the LFE subwoofer, so if you have 2 different kinds of subwoofers and one of them is a bottom feeder, use it.
ADVANTAGES You'll get more headroom from each subwoofer because now there isn't a single, summed signal of LFE and redirected bass going into both subwoofers. Each subwoofer only has to handle it's own, discrete signal. You'll have control of the LFE volume independent of the redirected bass volume during playback of any source that contains LFE signal.
FINAL THOUGHTS Well, there you have it. Though by no means the definitive multi-channel audio subwoofer set guide, I assure you that there is enough information to get you well on your way to understanding how to get the most benefit from the system you've labored over to research, purchase and set up.
Page 19
INDEX Advanced Setup Section 12 ADVANTAGES DUAL SUBWOOFERS -- MONO CONFIGURATION DUAL SUBWOOFERS, REBASE ROUTING CONFIGURATION: DUAL SUBWOOFERS, STEREO CONFIGURATION: PARAMETRIC EQUALIZATION PLACEMENT This is what happens DUAL SUBWOOFERS -- MONO CONFIGURATION Asymmetric Placement Of Dual Subwoofers: Asymmetric...Not symmetric FINAL THOUGHTS Overview 6 Calibration discs STEP #1: POLARITY TEST 7...
Need help?
Do you have a question about the UFW-10 and is the answer not in the manual?
Questions and answers