Some find that ignoring phase settings altogether and focusing instead on delay adjustment works best. Most subwoofers have a switch on the back that’s labelled ‘Phase’, and has positions of 0 and 180 degrees. You may find repeating this test with a variety of test media of further help. In the context of subwoofer integration, delay can be used to ensure that the direct sound from both subs & mains arrives at the listening position at the same time. Phase Alignment of Subs - Why I don't use the impulse response, Phase Wavelengths: The End Fire Cardioid Array made visible, Tokyo Seminar - 23 years of relationships. Slowly lower the gain at that frequency until the peak disappears and instead assumes a balanced, natural sounding position within the test media's spectral mix. You may find that adjusting the phase setting (typically done at the subs themselves or at the processor feeding them, if necessary) further smoothes an otherwise uneven main/sub splice. There are some things this processor can do very well and some it does poorly. Get the Audioholics AV Gear Guide Ebook FREE! And there are things it simply can't do at all. All Rights Reserved. In some … Re-adjust the gain as necessary. Listen to the quality of the sound. By this point in the setup process, you've already done quite a lot that hopefully has improved the integration of your subs with your system's mains. Then slowly sweep up, then down, the frequency scale; you're listening for that frequency where the boost is most noticeable. I'll assume for this segment of the set up process you're using a parametric equalizer. Here's one of the more efficient approaches I've seen. Active vs. For example, suppose your LCR main/front sub cluster is 5 meters from the listening position and the rear sub is 1meter from the listening position. The phase control operates over a range of 0 to 180 degrees. Screenshot from XTZ Room Analyzer II Standard – the unique Delay Alignment tool automatically identifies the best time delay to apply to the main speakers to align properly with the sub. With your PEQ bands zeroed out, begin playback of your test material and listen for any noticeable remaining peaks in response. Equalization. Before proceeding, here are a few cautions worth keeping in mind. Subwoofer Phase Delay and Equalization By Mark Sanfilipo — June 02, 2005. To check your sub's phase, play music with lots of bass, listen for a minute or so, and have a friend sitting by the sub flip the sub's 0/180-degree phase switch slowly back and forth. Setting the phase control to 180 degrees reverses the polarity of the subwoofer. III. Approach this one with caution: it can create as many sonic problems as it solves, especially when misapplied. Copyright © 1998–2020 Audioholics, LLC. This may not be at all possible to achieve . Now listen from all the other seats in the listening area, starting with those nearest your first listen test location. Making phase adjustments must be approached with the understanding it can do as much harm as good. Over the years I've seen a variety of techniques used for setting up an equalizer without any sort of measurement gear at hand. 5 m - 1m gives a flight distance difference of 4 meters. Together, they allow you to more effectively target those portions of the low frequency audio spectrum that need alteration. Now vary the Q value until the sound you are hearing sounds even more balanced or natural. Crossover is the frequency where speakers begin to roll off, and the subwoofer starts outputting bass notes and LFEs. This part of the procedure should be done with both subs & the mains on. Your email address will not be published. 9. 10. Calculate the time (in ms) or distance (in feet or meters) of flight from the front sub & LCR locations to the listening position as well as that from the rear sub to the listening position. Delay can effectively be used for a variety of purposes, in both consumer and pro audio. Knowing the speed of sound, you can quickly determine the time of flight differences (and thus the amount of delay) between signals for many subwoofer arrangements, but how would you calculate for arrangements such as those showing in Fig 39a? Setting the Crossover. Although delay adjustment can serve a variety of purposes, I include it with phase adjustment simply because as you alter delay, you alter phase. 9. It uses a bare minimum of test media, your ears and if you like, appropriate measurement gear. We'll focus on the most noticeable resonance first. “Let our rigorous testing and reviews be your guidelines to A/V equipment – not marketing slogans”. You may find that adjusting the phase setting (typically done at the subs themselves or at the processor feeding them, if necessary) further smoothes an otherwise uneven main/sub splice. Once that frequency of max. Bruce recalled his days setting up sound systems when he'd use a 1.5-volt battery to test subwoofer phase. Sorry if I bother you with amateur-questions, but I’m really stuck in a venue where I need to align three sub positions with stereo mains + delays. As of now, my knowledge about phase vs time is limited, and I can’t figure out how to do the alignment from the phase-readouts. The purpose here is to determine a consensus or acceptable compromise in perceived response across all the seats in the listening area. Subwoofer phase. Finally, with both subs on, adjust further, but only if necessary. Indeed, you may find that an acceptable level of performance is achievable at only one seat within the listening area. Phase / Delay Adjustment . Adding delay to the subwoofer signal can sometimes help the subwoofer to integrate better with the loudspeakers in the room. A passive subwoofer is just a woofer or woofers in an enclosure that must be driven by an external amplifier. Delay can also be thought of as an electronic means of establishing subwoofer placement symmetry or minimizing path differences between the subs and the listening position. boost effect has been identified, you've targeted the resonance frequency.