Fine tuning and calibrating the HSU subwoofer to your room makes all the difference between tight, musical and ‘fast’ bass and sloppy and boomy bass.

Placement and seating location are critical for optimal bass experience. We offer individualized subwoofer placement recommendations if you send detailed room layouts to techsupport@hsuresearch.com. We also recommend doing the subwoofer crawl to determine the best location for your sub. 

Subwoofer Crawl

Place the subwoofer in your main listening position with the woofer at ear level. Place the SPL meter (or if you use REW, your REW mic) at each of the possible sub placement options. Measure the frequency response at each of these locations. Use our test CD if you are using a SPL meter. Run the frequency sweep if you are using REW. Choose the location that has the flattest response and/or the highest SPL. When taking these measurements, make sure only the subwoofer is playing. 

If the subwoofer is used for only home theater

1. Set the crossover to OUT, volume 10 o’clock, phase 0, Q 0.7, one port open (N/A for ULS), EQ1 on the subwoofer
2. Set crossover on the receiver to 80 Hz (unless the main speakers don’t go this low). 80 Hz is usually best compromise between localization of the subwoofer and best dynamic range for the main speakers and is considered the standard for THX.
3. Run auto room calibration on the receiver
4. Check the sub out level on your receiver. If it’s high (e.g. +8 dB), raise the volume on the subwoofer and re-run the calibration. If it’s low (e.g. -10 dB), lower the volume on the subwoofer and re-run the calibration. Aim for -3 dB on the sub out level.
5. Most people like a bit more bass for home theater so it’s fine to bump the sub out from -3 to 0 dB. With too high a sub out level, the sub out can overload prematurely. With too low a sub out level, the auto on function on our subwoofer will be less sensitive. Hence 0 dB is best.

If the subwoofer is used for only two channel stereo system

With no high pass filter:

1. Set the crossover to IN on the subwoofer
2. Adjust the crossover frequency to bring the subwoofer in where the main speaker starts to fade out
3. Adjust the subwoofer volume for balanced bass (you can use our provided test CD)

With high pass filter:

1. Set the crossover to IN on the subwoofer
2. Set the crossover frequency to match the high pass filter frequency
3. Adjust the subwoofer volume for balanced bass (you can use our provided test CD)

If the subwoofer is used for both a two channel stereo system and home theater

We recommend calibrating first for the two channel music system, then for home theater.

Two Channel Stereo Calibration

With no high pass filter:

1. Set the crossover to IN on the subwoofer
2. Adjust the crossover frequency to bring the subwoofer in where the main speaker starts to fade out
3. Adjust the subwoofer volume for balanced bass (you can use our provided test CD)

With high pass filter:

1. Set the crossover to IN on the subwoofer
2. Set the crossover frequency to match the high pass filter frequency
3. Adjust the subwoofer volume for balanced bass (you can use our provided test CD)

Home Theater Calibration

The home theater calibration is recommended to do second because you can rely on the receiver to do the bass management.

1. Set the crossover to OUT on the subwoofer
2. Set crossover on the receiver to 80 Hz (unless the main speakers does not go this low)
3. Run auto room calibration
4. Do not touch the volume and crossover frequency on the subwoofer during this calibration as these have been set optimally for the two channel system
5. Most people likes a bit more bass for home theater so it’s fine to bump the sub out on the receiver 3 dB to get more bass for home theater

Calibration only needs to be done once. Afterwards, if you listen to music, simply set crossover to IN on the subwoofer, and select your two-channel amplifier as your source. If you’re watching home theater, select receiver as the source and set crossover to OUT on the subwoofer. And in both scenarios, the sub should stay in the optimal location as determined by your sub crawl.