A source, an amplifier and loudspeakers have to agree

A hi-fi system is often bought as three decisions that never meet. The source is chosen for its features, the amplifier for its power figure, and the loudspeakers for the way they sounded in a different room. Each choice can be defensible. Together they can still be a muddle: hiss under quiet music, a volume control that is already too loud at the first step, or bass the speakers are blamed for when the amplifier has simply given up.

The recording has already been made. The system does not improve it. It can pass it with little extra character, or it can add noise, compression and a tone of its own. Matching is the work of keeping those additions small, and of making sure no single box is asked to do a job it cannot do.

The source has one job

A source, whether it is a streamer, a disc player or a turntable and its phono stage, has to deliver a clean signal at a sensible level. “More detail” is a poor buying brief. Detail is what remains when noise, glare and an exaggerated treble are not covering the recording. A source that is only impressive in the first minute is often just brighter or louder than the one it replaced.

Listen for what the source should not do. It should not hiss when the music is quiet. It should not click, drop out or change level when you walk across the room, if it is on a network or a wireless link. It should start, stop and resume without a ceremony. Those failures are louder, in daily use, than a small difference in the converter.

If you use digital volume control in the source as well as a knob on the amplifier, decide which one is in charge. Two volume controls stacked together often leave you in a range where the signal is being turned down hard and then amplified again. Pick one, set the other near unity, and leave the arrangement alone so later comparisons mean something.

The amplifier has to control, not merely be powerful

Power on a brochure is a maximum, measured under conditions you will not reproduce. What you hear is whether the amplifier stays composed at the level you actually use, with the speakers you actually own. A large wattage figure does not guarantee grip. A small one does not guarantee refinement. Both can be wrong for the load.

The practical signs are ordinary. At a normal level, bass notes should start and stop, not bloom into the next note. A voice should not harden when the chorus arrives. Turning the knob up a little should make the music louder, not thicker and shoutier. If the amplifier only sounds in control with the volume barely open, you are using the noisiest, least precise part of the control, and you may have too much gain for the speakers.

Gain is the forgotten match. Sensitive loudspeakers, or a source with a high output, can make a powerful amplifier unusable: the first few degrees of the knob cover everything from silence to too loud. The cure is a lower-gain input, a source with its own sensible output setting, or an amplifier whose control is finer. It is not a more powerful amplifier. More power helps when you run out of level before the music is complete, and the sound is compressing rather than simply being quiet. Name that problem before you buy watts.

The loudspeakers set the terms

Speakers decide how much air has to be moved, how much of the room joins in, and how honest the rest of the chain is allowed to be. A small speaker will not produce deep bass because a larger amplifier has been attached. It may play louder and cleaner up to its limit. Past that limit it distorts, and a stronger amplifier can reach the distortion sooner if you use the extra power.

Sensitivity and impedance are clues, not personalities. A sensitive speaker needs less voltage for the same level, which is helpful in a large room or with a modest amplifier, and risky if every source is already hot. A difficult load asks the amplifier for current. If the bass collapses or the amplifier runs hot and brittle only with this pair, believe that symptom. Do not average it away with a review of the speaker in a different system.

Placement still matters more than the next box. Distance to the walls changes bass, and the chair changes which notes you hear. If the system sounds boomy, move the speakers and the seat before you replace the amplifier. A new component cannot repeal a room mode. Judge the electronics only after the speakers have a fair position, on recordings you already know.

Hear the match, not the advertisement

Use two or three familiar pieces: a voice in the centre, a bass line with sustained notes, and something with a quiet opening. Play them at the level you would keep for an hour. Then try these checks.

• Turn the system up during a quiet passage and listen for hiss before the music. If hiss arrives first, the gain structure or the source is wrong.
• Find the lowest knob position that is already satisfying. If it is the first step, you have too much gain. If satisfying never arrives before the sound strains, you are out of clean level.
• Change one box, or one placement, and put it back if you cannot describe the difference without saying “better”. Louder is not better. You have to match the level by ear or the new piece wins unfairly.

Write down the arrangement that worked: which input, where the source volume sits, where the speakers are. The note is the system. Without it, the next cable or the next evening will be blamed for a setting you forgot.

A matched system is not the most expensive object in each category. It is a source that stays quiet, an amplifier that has a usable range of level, and loudspeakers that can produce that level in your room without the bass or the voice falling apart. When those three agree, stop. Another box is justified only when you can point at the limit the present three have already shown you.

Key takeaway

• Match noise, usable volume and control before you match a specification sheet.
• Change one box at a time, on the same recordings, or you will not know which part improved.