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Mono subwoofer amplifier — 600 watts RMS x 1 at 2 ohms

Item # 109GTR601

JBL's GTR-601 mono amplifier powers your subwoofer with up to 600 watts RMS from a compact chassis that takes up...

Read more from Crutchfield writer, Buck P.

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$349.99 -$210.00 Price break


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About the JBL GTR-601

Bass with style

JBL's GTR-601 mono amplifier powers your subwoofer with up to 600 watts RMS from a compact chassis that takes up very little space. A low-pass filter clears the way for your sub to play clean, powerful bass, while a bass boost and phase switch help you get the sound just the way you want it.

Bass with style

JBL's GTR-601 mono amplifier powers your subwoofer with up to 600 watts RMS from a compact chassis that takes up very little space. A low-pass filter clears the way for your sub to play clean, powerful bass, while a bass boost and phase switch help you get the sound just the way you want it.


This amplifier can accept low- or speaker-level inputs so it'll work in almost any system, and the package includes screw-on RCA-to-bare wire adapters for the speaker-level signal. The GTR-601 sub amp will integrate perfectly into a system that uses a matching JBL GTR-102 or GTR-104 full-range amplifier with its handy Bluetooth® connection.


JBL GTR-601 adjustment panel

Confused about impedance? Check out our article on matching subs and amps.


Product highlights:

  • mono subwoofer amplifier
  • 380 watts RMS x 1 at 4 ohms (600 watts RMS x 1 at 2 ohms)
  • variable low-pass filter (32-320 Hz, 12 dB/octave)
  • variable bass boost (0-9 dB at 45 Hz)
  • phase switch (0, 180 degrees)
  • preamp and speaker-level inputs
  • speaker wire-to-RCA adapters included
  • fuse rating: 35A x 2
  • 4-gauge power and ground leads recommended — wiring and hardware not included with amplifier
  • 10-3/8"W x 2-3/16"H x 7"D
  • warranty: 1 year
  • Our 60-day money-back guarantee
  • MFR # GTR-601

What's in the box:

  • Mono amplifier
  • Four 35A ATO fuses (2 installed)
  • 2 Bare wire-to-RCA adapters
  • 4 Mounting screws (M4 x 52mm)
  • Quick Start Guide

Customer reviews

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JBL GTR-601 Reviews

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Overview: The JBL GTR-601 is part of the GTR Stadium series of high-performance amplifiers. This Class D mono subwoofer amplifier will accept both high-level and low-level inputs. Class D amplifiers are highly efficient and compact, generating a lot of power without drawing much current or generating heat. The amp comes with spare fuses, speaker wire-to-RCA adapters, and mounting hardware.

Power Output: The GTR-601 delivers the following power output:

  • 380 watts x 1 at 4 ohms (<0.1% THD+N)
  • 600 watts x 1 at 2 ohms (<0.1% THD+N)

Protection Circuitry: The amplifier features protection circuitry for thermal overload, over- or under-voltage (<9V or >16V), and short circuits. The LED on the top of the amp glows red if the amp goes into protection mode.

Controls: The GTR-601's controls are located on one side of the amplifier. The rotary controls require a small screwdriver (not included) to make adjustments. The amp controls include:

  • Gain: The rotary gain control let you match the amp's input sensitivity to the output of the source unit. The input sensitivity range of the amplifier is 0.2V and up for a low-level input, and up to 20V for speaker-level input.
  • Input Level: The Input Level switch lets you select the type of input you are using. For high-level input, there are two settings: Hi1 and Hi2. If the audio system fails to play with an amplifier connected to its output, or you get a "speaker disconnected" message on your factory stereo, set the switch to the Hi2 position. The Hi2 position includes a circuit design to fool this type of factory system into "seeing" a speaker connected to its output.
  • Crossover: The amp features a non-defeatable low-pass filter that determines the upper limit of the frequencies that are sent to the subwoofer. You can adjust the cutoff frequency of the low-pass filter from 32Hz to 320Hz using the rotary control.
  • Bass Boost: The GTR-601 has a variable 0-9dB bass boost, centered at 45Hz. This allows you to dial in the amount of bass according to your personal taste.
  • Phase Switch: The amp has a 2-way Phase Switch that lets you invert the phase of the speaker output by 180°. When the subwoofer is out of phase with the other speakers in the vehicle, sound waves cancel each other and the bass response suffers. If the bass response is poor, inverting the phase of the subwoofer may improve it.

Connections: The JBL GTR-601 uses set screw terminals for the +12V power, ground, turn-on (remote) lead, and speaker outputs. The screws can be tightened/loosened with a Phillips-head or flat-head screwdriver (not provided). The amp connections include:

  • Power/Ground: The +12V Power and Ground terminals will accept up to 4-gauge wire. It is recommended that you use a minimum of 4 AWG power wire to the battery, with an in-line 70A fuse installed no more than 18" from the battery terminal. A 4 AWG ground wire (minimum) is also recommended, and attached to a metal area close to the amplifier.
  • Remote Turn-On: The Remote screw terminal will accept up to 8 AWG wire. Typically, an 18 AWG turn-on lead is included in an amplifier wiring kit.
  • Speaker Outputs: The amp features screw terminals for connecting two speakers. The terminals are wired internally in parallel. The amp's minimum speaker impedance is 2 ohms, so you can connect one or two 4-ohm subwoofers, a 2-ohm subwoofer, or one subwoofer with dual 4-ohm voice coils.
  • Speaker-Level Input: The amp includes two bare wire-to-RCA adapters for connecting the amp to a factory radio or aftermarket head unit without preamp outputs. You should attach the left and right speaker wires from the head unit to each adapter and plug the adapter's RCA plug into the amp.
  • Line-Level Inputs: The amplifier is equipped with one pair of RCA inputs for connecting stereo RCA patch cables from the head unit to the amp. If your source unit only has one subwoofer output, a "Y" adapter should be used to split the mono signal into two outputs.

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Customer Q&A

Crutchfield asked: Why did you buy this?
I'll be using this for a pair of RF P1 10" subs. I made my decision 100% off the reviews. [ Derick  Mar 20, 2019 ]
To complete my system. [ Todd  Mar 12, 2019 ]
I chose all these products from Troy and Garrets recommendations. Excellent customer service [ Phillip  Mar 12, 2019 ]
Brand, price [ TOBY  Mar 07, 2019 ]
Good reviews and great sale [ Ryan  Feb 22, 2019 ]
This amplifier has the rms output I required for my build and had some good reviews. [ DUSTIN  Feb 04, 2019 ]
Price vs performance compared to others with great reviews [ Jeremy  Feb 03, 2019 ]
recommended by Crutchfield expert Maverick [ Orlando  Jan 31, 2019 ]
Recommended by Crutchfield advisor [ Eduardo  Jan 25, 2019 ]
price, advice online help [ Jeffrey  Jan 24, 2019 ]
Cause the ones that I buy before don't work [ RUBEN  Jan 13, 2019 ]
Great brand [ chardonnay  Dec 14, 2018 ]
good price [ Ronald  Dec 07, 2018 ]
JBL quality, 600 watts RMS output, low price! [ J  Dec 02, 2018 ]
Class D amp having low power consumption with big output and a compact design. [ WASIM  Nov 30, 2018 ]
Sale and good reviews. [ John  Nov 27, 2018 ]
good price [ RYAN  Nov 26, 2018 ]
Compact size and watt rating. JBL products have served me very well in the past. [ Jack  Nov 21, 2018 ]
I chose this item because of it's specification, cost and most importantly, the reviews of those who purchase this item as well. [ ERROL  Sep 11, 2018 ]
a great customer service rep helped me choose it [ Douglas  Aug 23, 2018 ]
i chose this because i wasted my time and money on a sound ordnance sub woofer twice. [ John  Aug 07, 2018 ]
For all the reviews from costumers [ Carlos  May 14, 2018 ]
Oliver helped me pick it out. [ Jeff  Mar 12, 2018 ]
Sale price [ Marco Eduardo  Jan 29, 2018 ]
Taylor in customer service helped me a lot with this decision [ chris  Jan 05, 2018 ]
Perfect amp for the JL Audio Stealthbox [ Ronald  Dec 30, 2017 ]
I did not know what to order so I asked your Tech, Mark, and he helped me with this amp because I already ordered the subwoofer. It was much appreciated! [ JANICE  Nov 27, 2017 ]

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