Marantz PM6007 with DALI Oberon 5: are 45 watts enough for a floorstander?
The first suggestion German search makes on this amplifier, and the answer is 99.7 dB at three metres — enough for the room, 11.3 dB under cinema reference. The pearl is that the Denon PMA-600NE everyone compares it with computes to the same number, to the decimal.
99.7 dB at three metres — and the Denon most people compare it with gives exactly the same number.
Level. 88 dB at 2.83 V/1 m on a 6 Ω nominal load is 86.75 dB per watt. The PM6007 publishes 45 W at 8 Ω and nothing at 6, so the calculation uses the 8 Ω figure:
| Distance | Continuous SPL | Against 105 dB |
|---|---|---|
| 1 m | 103.3 dB | −1.7 dB |
| 2 m | 97.3 dB | −7.7 dB |
| 3 m | 99.7 dB | −11.3 dB |
| 4 m | 91.2 dB | −13.8 dB |
How much amplifier would close the gap. Going from 99.7 dB to the 105 dB reference at three metres is 11.3 dB, which is 13.5 times the power: 607 W. Moving the chair from three metres to two buys 3.6 dB and costs nothing. That is the honest shape of the answer to «should I get a bigger amplifier» — the room is a cheaper variable than the amplifier by two orders of magnitude.
The pearl: the Denon PMA-600NE gives 99.7 dB too, the same number to the decimal. Both publish 45 W at 8 Ω, and for a 6 Ω speaker neither publishes anything else, so both pages compute from the identical figure. German search suggests these two amplifiers against this speaker as if the choice were about level; for the level question they are one amplifier. The Denon does print a second number — 70 W at 4 Ω — but at 0.7 % distortion against the 0.07 % of its 8 Ω rating, and our calculation will not reach for a 4 Ω figure on a 6 Ω nominal load. Where the two genuinely differ is in everything a level calculation cannot see.