Do a side by side. It should be similar with those two RMS figures.
Keep in mind that what constitutes 'decent volume' is quite subjective.
What kinds of volume lose will I notice if I go from my JVC RX-DP10vbk to the Mcintosh MC58?
I understand the difference in sound quality, I want to know if I will get decent volume.
I currently have the JVC receiver driving a pair of Infinity SM 150 speakers.
The highest that I think I have turned the JVC up to is about -18DB.
The specs for the two amps and the speakers are listed below.
JVC RX-DP10VBK specs:
120 watts x 2 min. RMS, both channels driven into 8 ohms from 20Hz to 20kHz with no more than 0.02% THD, 120 Watts x 2 min. RMS, driven into 4 ohms, with no more than 0.07% THD. 4 ohm Rated (FTC)
120 watts x 7 min. (2 Front, 1 Center, 2 Rear speakers) RMS, into 8 ohms, 1kHz, 0.2/0.7% THD
Infinity SM 150 Speaker specs
Bass: 1 x 15 in. (38.1 cm) polypropylene coated woofer
Mids: 2 x 4.5 in. (11.4 cm) dome polypropylene coated midranges
Highs: 1 x 1 in. (2.5 cm) dome polycell tweeter
Suggested for amplifiers with: 10-300 Watts per channel
Frequency range: 44 Hz - 25 kHz
Crossover frequencies: 500 Hz, 5500 Hz
Sensitivity: 102 dB
Impedance: 8 Ohms
The Mcintosh MC58 Specs
Power Output Per Channel
50 watts into 4 ohm load and 30 watts into 8 ohm load is
the minimum sine wave continuous average power output
per channel, all channels operating.
Power Output Bridged
100 watts into 8 ohm load is the minimum sine wave continuous
average power output per channel, all channels operating. Total Harmonic Distortion

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