The right amplifier for your speakers is the one that delivers at least the manufacturer's recommended power at the speakers' impedance, with headroom to spare. For €349 bookshelf speakers like the Acoustic Energy AE100² (87 dB, 4 ohms, 75 W recommended), the WiiM Amp Pro (€487, 60 W at 8 ohms and 120 W at 4 ohms) is more than enough. For the DALI Menuet (€1,298), the Cambridge Audio CXA81 Mk II (€1,199, 80 W at 8 ohms) has the energy they need. Below we explain how to read three numbers on the spec sheet and give concrete pairs we stock.
How to read sensitivity (dB)
Sensitivity tells you how loud a speaker plays with one watt, measured at one meter. The higher it is, the less power you need for the same volume. Every 3 dB more means half the power required. The Acoustic Energy AE320² is rated at 90 dB and the AE300² at 86 dB, a 4 dB gap that works out to more than double the power for the same sound level.
That is why two speakers of the same size can call for very different amplifiers. In medium-sized rooms, speakers above 88 dB work well with modest amplifiers. Below 86 dB it pays to think about more power.
How to read impedance (ohms)
Impedance is the resistance a speaker presents to the amplifier. The lower it is, the more current the amplifier has to supply. Most speakers are 8, 6 or 4 ohms. The DALI Menuet and the AE100² are 4 ohms, the AE300² is 6 ohms and the AE320² is 8 ohms. In many amplifiers the power rises when the load drops from 8 to 4 ohms, so we always look at both figures. The WiiM Amp Pro, for example, is rated at 60 W at 8 ohms and 120 W at 4 ohms.
How to read recommended power
Many manufacturers give a range, like the 20 to 100 W for the DALI Menuet, or a maximum, like the 200 W for the AE320². That is the window in which the speaker performs at its best. The lower limit keeps an amplifier from straining. The upper limit protects the speakers. Stay inside the range, preferably in the upper half.
How many watts do I need for my room?
As a rule of thumb, this is the scale we use in the store. For a room up to 15 m² (about 160 sq ft) and relaxed listening, 30 to 50 W is enough. Between 15 and 30 m² it is worth having 60 to 100 W. Larger rooms, or anyone who listens loud, should aim for 100 W or more. These are starting points, because speaker sensitivity and room acoustics change the result a lot. It is worth listening before you decide, in our listening room in Lisbon.
Why is it better to have too much power than too little?
A loud passage of music can demand many times the average power. An amplifier that runs short of headroom clips, meaning it distorts. That distortion is what can damage the tweeters. With headroom, the amplifier works comfortably and the sound stays clean, even at peaks.
Integrated amplifier or streaming amplifier?
A classic integrated amplifier amplifies and connects your sources. It waits for an external streamer or player. A streaming amplifier combines both functions in one box, which simplifies setup and saves space, so it is the natural choice if you mostly listen to streamed music and TV. If you want the flexibility to swap each component in the future, the integrated leaves more room. We explain the differences in our guide to integrated amplifier or pre + power. See also the integrated amplifiers collection.
Four store pairs, by budget
| Speakers | Amplifier | Total |
|---|---|---|
| Acoustic Energy AE100² (€349) | WiiM Amp Pro (€487) | €836 |
| Acoustic Energy AE300² (€799) | WiiM Amp Ultra (€635) | €1,434 |
| DALI Menuet (€1,298) | Cambridge Audio CXA81 Mk II (€1,199) | €2,497 |
| Acoustic Energy AE320² (€2,200) | Cambridge Audio Evo 150 SE (€2,399) | €4,599 |
Up to €900, AE100² with WiiM Amp Pro
The AE100² is rated at 87 dB and 4 ohms, with 75 W recommended. The WiiM Amp Pro delivers 120 W at 4 ohms, with built-in streaming and HDMI ARC for the TV. It is a complete first system, with nothing else to buy besides cables.
Up to €1,500, AE300² with WiiM Amp Ultra
The AE300² is rated at 86 dB and 6 ohms, with 100 W recommended. The WiiM Amp Ultra delivers 100 W per channel at 8 ohms, with a touchscreen, RoomFit room correction and HDMI ARC. The power covers the manufacturer's recommendation. The speakers' lower sensitivity appreciates the headroom.
Around €2,500, DALI Menuet with Cambridge Audio CXA81 Mk II
The Menuet is rated at 86 dB and 4 ohms, with 20 to 100 W recommended. The CXA81 Mk II delivers 80 W at 8 ohms and 120 W at 4 ohms in Class AB, with a built-in DAC and a balanced input. It is a pair that grows well, because you can add a streamer later.
Around €4,600, AE320² with Cambridge Audio Evo 150 SE
The AE320² is a 90 dB, 8 ohm floorstanding speaker with a recommended maximum of 200 W. The Evo 150 SE delivers 150 W per channel at 8 ohms, with StreamMagic streaming, HDMI ARC and MM phono. For a floorstanding system that plays music and TV, it is a very complete pair.
What to consider before buying
- Always look at power at your speakers' impedance, rather than settling for the watts at 8 ohms.
- Low sensitivity calls for more power. So does a large room.
- If you want TV sound, look for HDMI ARC on the amplifier.
- A budget goes further when it is balanced between speakers and amplifier. See our guide to how much a hi-fi system costs.
Frequently asked questions
How many watts do I need for my speakers?
It depends on the speakers' sensitivity and the room. For a room up to 15 m², 30 to 50 W is enough in most cases. Above that, start at 60 to 100 W.
Can I connect an amplifier that is more powerful than recommended?
Yes, as long as you do not run it at maximum. The risk to speakers comes from the clipping of amplifiers that run out of headroom.
Do I need a separate DAC or streamer?
No, if you choose a streaming amplifier like the WiiM Amp Ultra or the Cambridge Audio Evo 150 SE. With a classic integrated, yes, you need an external source.
Do active speakers replace the amplifier?
Yes, they have amplification built in. We explain the differences in active or passive speakers.
Also read integrated amplifier or pre + power and active or passive speakers.