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Bass withdrawals - new car

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  • #16
    This whole thing is a little atypical for the forum, but here's a sub tuning tidbit that would be equally applicable to integrating your fancy DSP controlled subwoofer in any room with overlapping mains.

    I found the RTA to lack resolution down low to really see the sharp nulls from cancelations in the bottom octaves. The only way to deal with these is by ear using a sine wave sweep. I generated a wave and ran it for the octave between 40 and 80Hz to search for cancellations. I had a few, primarily a problem in the 60Hz range. That's a good spot for some kick drum punch, so certain recordings were sounding a bit weak. With the tone sitting in a problem frequency, I adjusted the delay and phase of the sub with the DSP until the tone came back. Then by moving the frequency back up and down I settled on the best balance for all frequencies. First, get the cancellations handled with delay and phase, then apply EQ. You'll never EQ your way out of a cancellation null caused by the room or speaker interactions.

    This isn't as important when you have a proper high pass on your mains, since they're not fighting the sub in that case and you're really just hunting room modes at that point. But in this case, that was the best way to balance out that tricky octave.

    As for the DSP-LF unit, a second phone with Bluetooth to control the unit works like a champ. That app is really sensitive, and other Bluetooth activity like my watch and the car itself was definitely interfering and causing random disconnects when transferring settings that lead to corruption.
    Electronics engineer, woofer enthusiast, and musician.
    Wogg Music
    Published projects: PPA100 Bass Guitar Amp, ISO El-Cheapo Sub, Indy 8 2.1 powered sub, MicroSat, SuperNova Minimus