These are not the same size of amplifier: Emotiva BasX A1 has roughly 4x the power of Arcam A5. That is about 6dB, so it is a question of room size and how hard your speakers are to drive, not of one being the better amplifier.
| Area | Better | Why |
|---|
| Power | A | Emotiva BasX A1 has more power - 200W against 50W into 8 ohms. That is about 6dB - a different class of amplifier rather than a bigger version of the same one, and far more than most rooms will ever ask for. |
| Room size | depends | We rate Emotiva BasX A1 the better fit for a large room and a very large room, and Arcam A5 for desk or near-field listening, a small room and a mid-size room. Match the amplifier to the room you actually have, not the one you want. |
| Grip on hard loads | evenly matched | Both behave much the same into 4 ohms - output increases strongly (325W and 75W). |
| Noise floor | A | Emotiva BasX A1 is the quieter design on paper - 112dB against 106dB. Audible mainly with sensitive speakers in a quiet room. |
| Built-in DAC | B | Arcam A5 has a DAC on board; the other needs an external one, which is another box, another power lead and another purchase. |
| Analogue inputs | B | Arcam A5 takes more analogue sources - 3 against 2. |
| Phono stage | depends | Arcam A5 has a built-in phono stage (MM) and Emotiva BasX A1 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. |
| Headphones | depends | Only Arcam A5 has a headphone output. Worth something if you listen late, nothing if you never do. |
| Price | A | Emotiva BasX A1 costs less - $569 against $699 at list. |
| Watts per dollar | A | Emotiva BasX A1 is the cheaper watt - about $3 per watt against $14. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A Emotiva BasX A1 B Arcam A5
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?
Emotiva BasX A1 has the edge on paper, though not by much. The rows marked "depends" are more likely to decide this than the score is. 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 - Emotiva BasX A1 has the headroom, and headroom is what stops an amplifier hardening up on peaks. At desk distance or in a small room, 50 watts is already more than most people ever use, and the extra 150 watts would be headroom you pay for and never hear - we rate Emotiva BasX A1 poorly for near-field use for exactly that reason. If you play records, Arcam A5 saves you buying a phono stage; if you do not, ignore that row entirely.
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.