![]() ![]() Reflex speaker cabinets with low resonance frequency made things even worse.Ĭhoose a preamp having a "rumble filter" (high-pass filter). The introduction of solid state amplification with DC coupling extended the amplifier low frequency range down a few Hz and hey presto "woofer flapping". When the microgroove LP specification was made in the 1950s amplifiers and speakers did not reproduce below about 40Hz and nobody noticed "woofer flapping" because the amplifier and speaker didn't go that low down the frequency range. If the result is too low change to a cart that has lower compliance that will raise the resonance frequency. If the frequency result is too high change to a cart with higher compliance that will lower the resonance frequency. This is a filter (high-pass filter - stops low frequencies and allows high frequencies) that responds to the. The key word here is dynamic rumble filter. The HiFiNews test disc 2 has a track that permits estimation of the resonance frequency. About 35 years I came across an audio amplifier that had a dynamic rumble filter that reduced turntable rumble on quiet passages, but was turned off when there were load passages. In the Vinyl Engine section TOOLS is a cartridge+arm combination simulator that helps analyze the resonance frequency using the cart compliance values and the arm mass values. The specific intent was to eliminate the sound of turntable rumble and hum caused by the mechanisms of many record changers commonly used in that day and age. The cause is the sub-sonic resonance of the combination of the cart (the spring) and the arm (the weight). Recent advances in wideband amplifier design make it more important than ever before that turntable rumble and other subsonic components caused by record warps. Unlike the subsonic filter, the rumble filter rolled off at a much higher frequency range, starting around 60 hz or even 70 hz. I've recorded two videos, one showing the turntable's cartridge movement/oscillation and another one showing the speaker's driver excursion produced by it:ĭo you think that a record clamp would solve this issue?Ĭan it be a problem of cartridge setup/alingnment? Also, it's "louder" (higher) on the outer tracks. The amount of 'subsonic rumble' varies from one record to another, depending of the flatness of it. I'm afraid that running the system without filtering the output would damage the speakers. ![]() This makes the cartridge and the stylus move up and down, and it creates a subsonic wave (I'd guess around 10 or 15Hz) that is transmitted to the amplifier and then to the speakers. I think that this rumble is caused by the record not being enterely flat. low frequency (subsonic) energy, but also uses a unique Chat to Buy. Until now I didn't care too much about it as the phono preamp that I currently use (ART DJ Pre II) has a rumble filter, but I'd like to upgrade to a better preamp and so this can be a problem if the future preamp doesn't have a rumble filter. I've a "subsonic rumble problem" with my turntable. ![]()
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