AudioControl LC2i PRO Review: Active LOC for Factory Stereos

This AudioControl LC2i PRO review covers an active line output converter (LOC). It sits between a factory radio or factory amplifier and any aftermarket amplifier you add, and turns the speaker-level signal into the RCA-level signal the amplifier expects. Is it worth buying? For a car with a factory stereo you plan to keep, where you want a subwoofer or extra amplifiers without replacing the radio, it is a well-equipped option. The AudioControl LC2i PRO is priced at $169 on AudioControl's website. For that money it adds load matching, ground isolation and three turn-on methods that the $119 AudioControl LC2i does not list. If your factory system is simple, the cheaper model or another basic converter may be enough.

The unit scores 4.0 out of 5 on the rubric explained near the end. The verdict, pros, cons and full specification list sit in their own boxes on this page, so the text here covers how the converter works, what the rated figures mean and what to check before buying.

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AudioControl LC2i PRO design and build

AudioControl lists the unit at 6.9 by 3 by 1 inches including connectors, weighing 0.75 lb (0.34 kg). Integrated mounting brackets are built in, and the speaker and power connectors plug in. The box holds the converter, the ACR-1 dash remote, a 20 ft cable for that remote, the connectors, a manual and warranty paperwork. The housing material is not confirmed in the manufacturer's material.

The controls are a Main output level knob, a Bass output level knob, AccuBASS Threshold and Level knobs, and three switches for load selection, trigger mode and ground isolation. LEDs show power, AccuBASS activity and a Maximized indicator that lights when the unit's own output is clipping. That is a lot of adjustment for a small box. It helps with fine-tuning, but it asks for patience during setup.

Features and usability of the LC2i PRO

There are two channels of speaker-level input and two pairs of RCA outputs. The Main pair is full range and has its own level knob. The Bass pair is low-passed at 1 kHz, has a separate level knob and is the output the ACR-1 remote controls. AudioControl rates the input at up to 40 Vrms on the 20 kohm setting. Our calculation from that rating gives 400 W into 4 ohms (40 x 40 / 4 = 400). Maximum output is 9.5 Vrms (13 V peak), with a gain range of plus or minus 12 dB.

Load selection

Many modern factory amplifiers check for a connected speaker and may mute or change their output when they find none. AudioControl says the converter normally presents almost no load, so the load switch adds a speaker-like load to keep the factory amplifier passing audio. The positions are 20 ohm, 60 ohm and 20 kohm. According to AudioControl, 20 ohm suits late-model Dodge, Chrysler, Jeep, Ram and Fiat vehicles with a base system, 60 ohm suits the same brands with a separately amplified premium system, and 20 kohm suits everything else. The 40 V / 400 W rating is stated for the 20 kohm position only; input ratings for the other two positions are not confirmed.

Turn-on, grounding and remote output

The unit always needs constant +12 V power and a ground. It can switch on three ways: a 12 V remote input, GTO signal sensing (it detects the DC offset some factory systems output while the radio is on), or audio sensing, which turns it on only when audio plays. A three-position ground switch offers GND, ISO and 200 ohm settings to help with buzz or alternator whine, and the unit ships in ISO. A remote output can switch on up to two amplifiers, and AudioControl warns that more than two may damage the unit. Because GTO sensing depends on a DC offset, a car whose chosen tap does not carry one needs the remote wire instead.

AccuBASS and the ACR-1

AccuBASS is AudioControl's circuit for restoring bass that some factory systems remove as volume rises. Per the manual, you raise the radio volume until bass starts to fall away, turn the Threshold knob until the status LED lights and bass returns, then trim the Level knob to taste. It can be defeated or left on permanently. The included ACR-1 is a wired dash knob that acts only on the Bass output, as an attenuator from 0 to minus 19 dB. It cannot raise the level above the Bass Output Level knob setting.

AudioControl LC2i PRO rated performance

Our research found no independent lab measurements for this model. The figures below are the manufacturer's. AudioControl lists a frequency response of 20 Hz to 50 kHz (plus or minus 1 dB), total harmonic distortion of 0.01% and a signal-to-noise ratio above 110 dB. The test level, bandwidth and load setting behind the distortion and noise numbers are not published in the material consulted. The AudioControl LC2i page lists 33 Hz to 100 kHz, so the PRO claims lower bass extension but a lower upper limit.

A converter cannot add content the factory source never supplied; it passes and reshapes what it receives. The practical benefit of a high output is gain structure. With up to 9.5 Vrms available, an installer can often set amplifier gains lower, a common way to limit noise pickup. The rated figures work out to a 4.75 times higher signal than a 2 V source, about 13.5 dB more (20 x log10(9.5 / 2)). The ACR-1 range of 19 dB corresponds to a voltage ratio of roughly 8.9 to 1 (10^(19/20)), which is plenty of trim for a subwoofer that is too loud at night.

Installing the AudioControl LC2i PRO

Following the manual, connect +12 V and ground to the battery or a distribution block with 16 to 14 AWG wire. Protect the +12 V line with a 1 A fuse placed close to the battery, and mount the unit where heat, moisture and dirt will not reach it. When drilling, avoid fuel lines, brake lines and existing wiring. Disconnecting the battery negative before wiring is standard practice. Connect the left and right RCAs correctly, set the Main and Bass levels, then set AccuBASS.

For level matching, AudioControl suggests setting the factory system to its maximum undistorted volume, then raising the converter output toward your amplifier's input limit and backing off if the Maximized LED turns on. Keep the volume low while setting levels, because clipping can damage speakers and sustained high volume can damage hearing. Many factory systems split frequencies across their outputs, so choose a full-range tap where one exists. Check your vehicle's wiring information before cutting or tapping any speaker wire.

After setup, daily use is simple. The factory volume control sets the overall level, and the ACR-1 adjusts the subwoofer.

AudioControl LC2i PRO against three rivals

The closest alternative is the AudioControl LC2i, which lists the same output voltage and input rating for $50 less, but without load selection, a ground switch or audio-sense turn-on. Older retailer pages describe the ACR-1 as an extra on that model, while AudioControl's current page lists it as included, so confirm what a given listing ships with. The PAC LPA-2.2 matches the PRO on input rating, load options and ground options at $119, but its frequency response and distortion figures are not confirmed and its remote knob is optional. The PAC LP7-2R costs far less, at $46.95, with a much lower input rating and fewer features.

Feature	AudioControl LC2i PRO	AudioControl LC2i	PAC LPA-2.2	PAC LP7-2R
Price (USD)	$169	$119	$119	$46.95
Max speaker-level input	40 Vrms / 400 W (20 kohm setting)	400 W per channel at 4 ohm	40 V / 400 W at 20 kohm	55 W per channel (PAC rating)
Max output	9.5 Vrms	9.5 Vrms	9.5 V	Not confirmed
Load selection	20 / 60 ohm, 20 kohm	None listed	20 / 60 ohm, 20 kohm	None listed
Ground isolation	GND / ISO / 200 ohm	None listed	Common / ISO / 200 ohm	None listed
Turn-on	Remote in, GTO, audio sense	Remote in, GTO signal sense	Remote or DC offset	Signal-sensing remote turn-on
Remote level knob	ACR-1 included (bass output)	ACR-1 listed as included	LPA-REM sold separately	Included per retailer listing
Frequency response	20 Hz to 50 kHz, +/-1 dB	33 Hz to 100 kHz, +/-1 dB	Not confirmed	20 Hz to 20 kHz, +/-1.5 dB
THD / SNR	0.01% / above 110 dB	0.01% / above 110 dB	Not confirmed	Not confirmed

The price gap is easy to put in numbers. The PRO costs $50 more than the AudioControl LC2i, which is about 42% more (50 / 119), and the extra money buys the load, ground and turn-on options in the table rather than any change in rated output.

Who should buy the LC2i PRO and who should skip it

It is a good fit for:

• Drivers keeping a factory radio who want to add a subwoofer or amplifiers.
• Cars with a factory amplifier that may need a speaker load, especially the Chrysler-family models AudioControl names.
• Installs where ground noise is a risk and a ground switch gives another option.
• Anyone who wants a dash-mounted bass knob in the box.

Consider skipping it if:

• You are replacing the radio with one that has RCA preouts, because then no converter is needed.
• Your system needs more than two input channels or channel summing, which calls for a multichannel converter.
• You want equalization, crossovers or time alignment, because this is a converter and not a DSP.
• Your factory system is simple and budget matters more than extras, since a cheaper converter may do the job.

Price of the AudioControl LC2i PRO and what to check first

The AudioControl LC2i PRO is priced at $169 on AudioControl's website. Prices change often, so check the current listing. Shoppers who prefer Amazon can check the current price on Amazon, where the live figure is shown.

Make sure the listing is the PRO and not the plain AudioControl LC2i, because the names are close. Check what ships: AudioControl lists the converter, ACR-1, 20 ft cable, connectors, manual and warranty paperwork. Confirm that the unit is new and not refurbished, since one retailer labels its listing refurbished. Warranty terms conflict between sources: AudioControl's product page says 1 year, the 2020 manual says 5 years and a retailer listing says 2 years, so get the terms in writing. AudioControl says returns are handled case by case with a return authorization number. Budget for power wire, a fuse holder, RCA cables and speaker-tap connectors if you do not already have them.

Final verdict on the AudioControl LC2i PRO

The unit earns 4.0 out of 5. The rubric weights performance and function at 40%, features and usability at 20%, build quality and design at 15% and value for the price at 25%. Features score highest at 4.5, because the load, trigger and ground options address real integration problems. Performance is 4.0, since the rated output and input range are strong but come from the manufacturer alone. Build is 3.5, because the housing and construction details are not confirmed. Value is 3.5, because $169 is $50 above a sibling with the same rated output and input figures. Our research score is based on the rated figures and documented details above.

Criterion	Weight	Score (0-5)	Weighted points
Performance and function	40%	4.0	1.600
Features and usability	20%	4.5	0.900
Build quality and design	15%	3.5	0.525
Value for the price	25%	3.5	0.875
Total	100%	3.90, rounded to 4.0	3.900

For a car that keeps its factory radio and needs a clean subwoofer feed, the converter is a sound choice, and you can see the AudioControl LC2i PRO on Amazon before deciding.

Sources and further reading

• AudioControl LC2i PRO product page (price, specifications, box contents)
• AudioControl LC2i PRO user manual (wiring, fuse, AccuBASS setup, ACR-1 range)
• AudioControl LC2i product page (price, input rating, frequency response)
• AudioControl support article on load selection (load positions and vehicle guidance)
• PAC announcement of the LocPRO Advanced series (series features)
• PAC LPA-2.2 retailer listing (price and specifications)
• PAC LP7-2R retailer listing (price and specifications)