REL - Subwoofers for music

What is a good sub in a Hi-Fi system?

1. It can handle at least the lowest notes of the grand piano and counter bassoon at 27 Hz. Ideally, it should at least be able to cope with the CD format's lower limit of 20 Hz and the bass tub's really low notes.
2. It should offer musical quality sound so that, for example, acoustic instruments still have their musical content, body and flow and do not sound like an abnormal diffuse mass that only manages to make the room shake.
3. It should have the ability and capacity to be an extension of the speaker so that you no longer think about it.
4. It needs to be fast enough to avoid time errors with the speaker or the music. Ideally, you should buy 2 subwoofers placed next to the speaker. The HT series is designed for home theatre and lacks a high level input (specifically designed for stereo). The T/i series is of course capable of handling the home theatre situation with flying colours. The T/i series also has the high level function and can handle even stereo systems that are not too fast. The S and Reference series are made for stereo (although they of course handle home theater systems with ease). They have the speed and quality to be matched even against really fast speakers with very high quality.