Are you possible hearing a low frequency rumble out of it, thus making it sound like too much base. This is known a Acoustic Feedback. It is caused by the speakers producing too much volume, or the base turned up to too high. This condition is possibly linked by turntable being located to near the turntable. I would have to know this first.

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I didn't know that a turntable had bass control on it. If it has why not turn the bass down? I think it is your receiver not the turntable