MB Quart PA1-800.4 4-Channel Amplifier — Used Closeout

MB Quart PA1-800.4 Premium Pro 4-Channel Amplifier — Used Closeout

If you need four solid full-range channels but do not need the size, current demand, or output of the PA1-2400.4, the PA1-800.4 is the more sensible amplifier. MB Quart rates it at 100 watts × 4 at 4 ohms, 200 watts × 4 at 2 ohms, or 400 watts × 2 bridged at 4 ohms. That puts it in a useful range for door speakers, component sets, rear fill, or two compatible higher-power 4-ohm loads when the channels are bridged.

This is the smaller PA1 four-channel, and that matters in a real install. The chassis is only 5.81 × 4.45 × 2.0 inches, MB Quart specifies 8 AWG power and ground connections, and the published external fuse requirement is 80 amps. The PA1-2400.4 is the right move when the system is built around high-output pro-audio speakers or heavy midbass and needs several hundred watts per channel. The PA1-800.4 makes more sense when the speakers do not need that level of power and keeping the rack compact is more important than buying amplifier headroom you will never use.

Where We Would Use It

A straightforward four-speaker system is the obvious fit: front components or coaxials on two channels and rear speakers on the other two. It can also run two higher-power 4-ohm loads at up to 400 watts per channel when bridged. Bridging changes both the available channel count and the minimum load, so this is not a 400-watt-per-channel four-channel amp and MB Quart does not publish a 2-ohm bridged rating.

The built-in high-pass and low-pass filters adjust from 45 Hz to 850 Hz on both channel pairs. That is useful for protecting door speakers, band-limiting midbass, or dividing basic speaker roles, but it is not a substitute for a DSP in a fully active multi-way system that needs crossover points above 850 Hz, independent time alignment, EQ, or more precise filter control.

Factory Radio Integration

The PA1-800.4 accepts both low-level RCA and high-level speaker inputs. High-level input can make connection to an OEM source easier, but it does not automatically correct factory EQ, all-pass filters, bass roll-off, channel summing requirements, or other processing built into many factory systems. On a processed factory radio, the signal still needs to be checked before deciding that speaker-level input alone is the right integration method.

Used Closeout

This listing is for the used-closeout PA1-800.4, not a new retail unit. The reason to buy this one is value when the amplifier's channel count, impedance requirements, power range, and physical size already fit the build. Do not choose it only because it is less expensive than the PA1-2400.4; choose it when roughly 100 watts per channel at 4 ohms or 200 watts per channel at 2 ohms is actually the correct power range for the speakers being used. This is a final-sale closeout item.

Manufacturer Specifications

Manufacturer Features

• Low-noise preamplifier circuit
• Two pairs of nickel-plated RCA inputs
• High-level speaker input capability
• PWM MOSFET power supply
• Extruded aluminum heat sink with built-in fan cooling
• Thermal, overload, DC and speaker-short protection diagnostics

Plan speaker impedance, any bridged load, power cable, external fuse, grounding, airflow, and the vehicle's electrical capacity before installation.