240zracer...Take Hdm's advice, and get the rumble filter.
Your concern about maintaining stereo separation down to 18 Hz is not reasonable.
1. LP cutting practice (usually) is to mix to mono at low frequency.
2. Many people don't think that LF sound can be localized, hence the popularity of single subwoofers.
3. Although the cut-in frequency of the filter may seem a bit high, remember that its action is gradual, and considerable separation will be maintained well below the stated frequency. Thr filter designers were free to pick any frequency, and they built what worked best.
4. If you don't like it you can easily unplug it.
Your concern about maintaining stereo separation down to 18 Hz is not reasonable.
1. LP cutting practice (usually) is to mix to mono at low frequency.
2. Many people don't think that LF sound can be localized, hence the popularity of single subwoofers.
3. Although the cut-in frequency of the filter may seem a bit high, remember that its action is gradual, and considerable separation will be maintained well below the stated frequency. Thr filter designers were free to pick any frequency, and they built what worked best.
4. If you don't like it you can easily unplug it.

