Passive vs Active Soundbar

Two bars can look identical under a TV and need completely different wiring. The passive vs active soundbar question comes down to where the amplifiers live: inside the bar, or in a receiver or amplifier somewhere else. That choice decides what you run to the TV wall, what the equipment location has to hold, and how you match power and impedance.

Passive vs active soundbar at a glance

Whether a bar belongs in the room at all, rather than a receiver with separate speakers, is covered in soundbar vs AV receiver. This guide assumes a bar is the plan and compares the two types.

How a passive soundbar works

A passive bar is a long speaker cabinet. Most hold left, center and right drivers, each with its own crossover and its own pair of terminals, so an LCR bar needs three amplifier channels and three runs of speaker wire. Some bars are wired for two channels instead, so count the terminals on the spec sheet before you plan the run.

All the processing happens upstream. The receiver decodes the soundtrack, sets levels and delays, and handles bass management, so the bar’s low end is usually crossed over to a separate sub. Size the wire for the run and the load using our speaker wire gauge guide.

How a powered soundbar works

A powered soundbar is a complete small system. It takes audio from the TV, decodes it, applies its own processing and drives its drivers from built-in amplifiers. The TV usually becomes the source switcher, with the bar on its HDMI ARC or eARC port; what each version can carry is set out in HDMI ARC vs eARC.

• Power: the bar needs mains power at its location, which means a receptacle near the TV.
• Control: one remote, or the TV remote over HDMI CEC.
• Extras: many pair with a wireless sub or rear speakers made for that model.
• Limits: amplifier power, processing and decoding are fixed at purchase.

Choosing a passive soundbar amplifier

The passive soundbar amplifier is normally the front channels of an AV receiver. A separate multichannel amplifier fed by a processor also works. The AV receivers category and the amplifiers category list both kinds.

• Channel count: one amplifier channel per bar section, plus whatever the surrounds need.
• Impedance: the amplifier must be rated for the bar’s minimum impedance, not just its nominal figure.
• Power: the amplifier’s rated output per channel should fall within the bar’s power handling range.
• Heat: the amplifier goes in a ventilated location; output stage efficiency is compared in class D vs class AB amplifiers.

Compare amplifier ratings on the same basis. Under the FTC’s amplifier rule, 16 CFR 432.3, rated power is minimum sine wave continuous average power per channel, with all associated channels fully driven, at 8 ohms across 20 Hz to 20 kHz without exceeding 1.0 percent THD+N. Section 432.2 requires that figure to be labeled “FTC Power Output Rating”.

Impedance and power handling of passive soundbars

A passive bar’s spec sheet usually gives a nominal impedance, often 6 or 8 ohms, and sometimes a minimum. Impedance varies with frequency, so the minimum is the figure that matters to the amplifier. Never wire two sections, or a bar and another speaker, in parallel on one channel without doing the arithmetic: two 8 ohm loads in parallel present 4 ohms.

Power handling is usually given as a range, a minimum and a maximum. The lower figure is generally the least amplifier power the maker suggests; the upper one is the most the bar is designed to take. An underpowered amplifier driven into clipping is widely held to be a risk to tweeters, so headroom beats a marginal match.

A worked loudness check

Sensitivity is quoted at 2.83 volts at 1 meter, which is 1 watt into 8 ohms (2.83 squared divided by 8). Assume a bar of 88 dB sensitivity, a seat 3 meters away, and free field loss of 20 times log10 of the distance. Real rooms add reflections, so this is conservative.

1. 1 watt at 3 meters: 88 minus 9.5 is about 78.5 dB.
2. 50 watts: add 10 times log10(50), about 17 dB, for about 95.5 dB.
3. 100 watts: add 3 dB more, about 98.5 dB. Each doubling of power adds only 3 dB.

Where each type fits in a custom install

Both types belong in professional work; the room and the rest of the system decide.

• Media rooms and main living rooms with a rack: a passive bar driven by the receiver, a sub, and in-ceiling surrounds. The bar becomes the front stage of a real system.
• Bedrooms, kitchens and secondary TVs: a powered soundbar, with no equipment location to find.
• Retrofits with no wire path: a powered bar, since it needs only power and one short cable behind the TV.
• Distributed commercial audio: passive bars are low impedance speakers, not 70 volt models; see 70V vs 8 ohm speakers before tapping one into a paging line.

Mounting height, centring and the remote sensor apply to both types; see where to mount a soundbar.

Wiring the TV wall for each type

A passive bar needs only low voltage cable at the TV: speaker wire stubbed out behind the bar, rated for in-wall use, plus the TV’s own power and HDMI. A powered bar needs a receptacle within reach of its cord, and a power cord must never be fished through the wall. Pulling speaker wire to the bar position during a prewire keeps the passive option open later.

The bass usually comes from a separate sub with either type. The subwoofer category lists powered subs for a passive front stage.

Where to find soundbars and amplifiers

The sound bars category lists passive soundbars by part number, sized for 50 to 65 inch and 70 to 80 inch TVs, within the Bursma audio video division. For pricing and availability, ask your sales representative through the Bursma contact page, or open a Bursma dealer account.

Frequently asked questions