One is a streaming all-in-one and the other is an amplifier. Judge them on how many boxes you want and what you already own, not on the spec sheet alone.
| Area | Better | Why |
|---|
| Power | A | SVS Prime SoundBase has more power - 75W against 40W into 8 ohms. That is about 2.7dB, so it plays usefully louder before it runs out and has more in hand on peaks. |
| Room size | depends | We rate SVS Prime SoundBase the better fit for a mid-size room, a large room and a very large room, and NAD C 328 for desk or near-field listening and a small room. Match the amplifier to the room you actually have, not the one you want. |
| Grip on hard loads | A | SVS Prime SoundBase holds up better into a 4-ohm load: its output nearly doubles to 150W, where the other barely increases. That matters with demanding speakers far more than the 8-ohm figure does. |
| Noise floor | B | NAD C 328 is the quieter design on paper - 100dB against 90dB. Audible mainly with sensitive speakers in a quiet room. |
| Built-in DAC | evenly matched | Both have a DAC on board with much the same capability. |
| Streaming | A | Only SVS Prime SoundBase has AirPlay 2, Chromecast and DTS Play-Fi. |
| Analogue inputs | evenly matched | The same number of line-level inputs (2). |
| Phono stage | depends | NAD C 328 has a built-in phono stage (MM) and SVS Prime SoundBase does not. Decisive if you own a turntable, completely irrelevant if you do not - and an outboard phono stage is easy to add later either way. |
| Room to grow | evenly matched | The same expansion options on both. |
| Shelf space | depends | SVS Prime SoundBase takes up about 62% less shelf area (517cm² against 1349cm²), and it is 86mm shallower, which is the measurement that decides whether a rack door shuts. |
| Price | evenly matched | Priced within a few per cent of each other. |
| Watts per dollar | A | SVS Prime SoundBase is the cheaper watt - about $9 per watt against $17. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A SVS Prime SoundBase B NAD C 328
depends neither is better in the abstract - it turns on your room, your system or how you will use them. Only specs published for both amplifiers are judged; anything missing on either side is left out rather than guessed.
Which should you choose?
SVS Prime SoundBase has the edge on paper, though not by much. The rows marked "depends" are more likely to decide this than the score is. If your speakers are a difficult load - 4 ohms nominal, big woofers, or a sensitivity in the low 80s - SVS Prime SoundBase is the safer partner, because how an amplifier behaves when the impedance drops matters more than its 8-ohm rating. Start with the room. In a large or open-plan room, or with speakers that are hard to drive - low sensitivity, or an impedance that dips - SVS Prime SoundBase has the headroom, and headroom is what stops an amplifier hardening up on peaks. At desk distance or in a small room, 40 watts is already more than most people ever use, and the extra 35 watts would be headroom you pay for and never hear - we rate SVS Prime SoundBase poorly for near-field use for exactly that reason.
What a spec sheet cannot show: how either sounds with your speakers, how the controls feel day to day, and what the app is like to live with - which is where most all-in-one amplifiers are actually won or lost. Power figures are the manufacturers' own and are not measured to a common standard, so treat small differences as noise. If you can hear both, that will tell you more than any row above.