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Boston Acoustics SA1

Subwoofer amplifier

13 Reviews | 3 questions - 8 answers

Item # 065SA1

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Our take on the Boston Acoustics SA1

The SA1 amplifier provides high-quality power for up to two compatible Boston Acoustics subwoofers. Selectable crossover and equalizer settings let you achieve an optimal blend of sound with your other speakers. The auto on/off feature allows for more streamlined operation — you won't have to take any extra steps to power on this amp before listening to music or watching a movie. Plus, the SA1 can be stacked with the rest of your audio components or rack-mounted in a closet or cabinet for out-of-sight installation.

Well built and was able to drive twin subs. auto shut off works great.

Anonymous, Pennsylvania

What's in the Box:

  • SA1 Subwoofer amplifier
  • 5.75' AC power cord
  • Product manual
  • Warranty sheet

Product Highlights:

  • 140 watts (mono) RMS into 8 ohms, or 210 watts RMS into 4 ohms
  • gold-plated stereo line-level input
  • unfiltered LFE (Low Frequency Effects) input for connection to a home theater receiver's subwoofer output
  • two sets of binding posts for speaker-level output
  • continuously variable 40-160 Hz, 24 dB/octave low-pass crossover
  • selectable auto-sensing power on/off
  • selectable equalizer settings
  • phase control
  • selectable 12-volt trigger for use with 3rd-party control systems
  • rack-mountable design
  • detachable AC power cord
  • 3-1/2"H x 19"W x 12-1/2"D
  • warranty: 1 year
  • Our 60-day money-back guarantee

Boston Acoustics SA1 Reviews

Average Customer Review(s):

(13 Reviews)
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Hands-on research

Product Research



Overview: The SA1 amplifier is designed to be used with the Boston Acoustics line of installed subwoofers. One SA1 amplifier can power up to two of the same model subwoofer.

Variable Crossover: The amplifier has a built-in variable crossover that makes it easy to achieve a seamless blend with the main speakers, while the 24dB/octave low-pass filter prevents the subwoofer from being easily localized by the ear, increasing placement flexibility. The crossover point may be adjusted from 40-160 Hz.


Front Panel Controls:

  • Phase Switch: switches the polarity of the two speaker outputs; the correct setting is that which yields the fullest bass
  • Low-pass Knob: allows you to adjust the low-pass crossover point from 40-160 Hz
  • Volume Knob: allows you to adjust the volume level up or down until the bass level of your subwoofer matches the bass level of your speakers

Rear Panel Controls:

  • EQ Mode Switch: allows you to select one of the following EQ modes, depending where your subwoofer is located: Wall or Floor
  • 12-volt Trigger Switch: allows you to choose one of the following settings:
    • On: amp is on whenever the front panel switch is in the On position
    • 12V: amp is in standby mode whenever the front panel switch is in the On position. The SA1 turns on when a 12-volt power supply triggers it.
      • Note: Be sure to use a power supply that is rated as, "9 to 14 volts DC @ 1.5mA max. 1/8" diameter female plug with tip positive."
    • Music: amp is in standby mode whenever the front panel switch is in the On position. The SA1 turns on when an audio input signal triggers it.


Rear Panel Connections:

  • Line In: left and right RCA audio jacks; use this configuration if you wish to set the subwoofer crossover point using the SA1's low-pass control knob on the front panel or are using separate components, such as stereo preamplifier.
  • LFE/Xover Bypass: single RCA audio jack; in this configuration, the SA1's internal low-pass filter and front panel low-pass control knob will be bypassed
  • Speaker A/Speaker B: gold-plated binding posts; the binding posts are not 5-way because a plastic collar prevents their use with spade lugs

Our Product Research Team

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Q & A

Customer Q&A

Crutchfield asked  
Why did you buy this?

Based on your favorable user review, I will power my M&K subwoofers which have failed amps. [ J EDWARD  Mar 21, 2017 ]
They are great to power powered subwoofers whose amps have gone bad. [ Gerald  Aug 01, 2016 ]

3 questions already asked

To be honest I'm not sure. Here's what the manual says below. Hope this helps. SPA200 Specifications Amplifier Power (< 1% THD) 140 watts continuous, 8 ohms; 210 watts continuous, 4 ohms Crossover Frequency 40-160Hz 24dB/octave lowpass Inputs L and R stereo RCA line level and LFE RCA line level for crossover bypass 12-volt trigger input voltage 9 to 14 volts DC @ 1.5mA max. 1/8" diameter female plug with tip positive External Dimensions (H x W x D) 31/2 x 19 x 121/2" (89 x 483 x 318mm) without feet 35/8 x 19 x 121/2" (92 x 483 x 318mm) with feet 2 EIA Rack space with feet removed Weight 18 lbs (8kg) Finish Black Description Snell's new SPA200 subwoofer amplifier and accompanying subwoofer speaker system deliver the dynamic bass foundation that is essential for lifelike reproduction of movie soundtracks and music in the home. The amplifier has a built-in variable crossover that makes it easy to achieve a seamless blend with the main speakers, while 24dB/octave lowpass filters prevent the subwoofer from being easily localized by the ear, increasing placement flexibility. A crossover bypass position is provided for use with home theater electronics that perform their own bass management functions. The SPA200 is attractively housed in a standard compact 2 space x 19-inch rack enclosure. Auto on off and 12volt amplifier switching and easily accessible controls make the SPA200 subwoofer amplifier as convenient to use as it is exciting to listen to. [ Donald  Feb 06, 2017 ]
Hope this answers question. The SA1 is a subwoofer amplifier with a crossover frequency of 40-160 24db/octave low pass. It's a variable crossover for subs and not for mids/highs/lows on speakers. An active crossover would separate mids/highs/lows so no its not. [ Clyde  Feb 01, 2017 ]
Gerald Irons Jr's and Nick Mazzarella's answers are correct on how to connect a subwoofer amp like this one to a theater receiver. HTH!! My Bio: [ Paul  Sep 10, 2016 ]  Staff
Your amplifier has a coax amp output, that will connect to the lfe input on the sub amp. The sub amp then connects to the speakers through audio out speaker line. [ Nick  Sep 06, 2016 ]
The Boston Acoustic SA1 Subwoofer Amplifier is exactly that. An amplifier that will power up to 2 seperate subwoofers that are passive. You connect your subwoofer preamp output from your receiver or integrated amplifier to the line input of the SA1. Then you run your speaker wires as you would any other type of speakers positive to positive and negative to negative and you are set. This amplifier is meant for passive subwoofers. It may as in my case also be used in powered subwoofers that have bad factory amps by simply bypassing the subwoofers factory amplifier and connecting the positive and negative cables from the SA1 to the positive and negative posts on your subwoofers. I use it this way first disconecting the subwoofers from the bad factory amps and connected them to the subwoofers passing the cables thru the exhaust ports. It's better and cheaper that having the factory plate amp repaired or replaced if the warranty is expired! [ Gerald  Sep 06, 2016 ]
If you purchased the product from Crutchfield, feel free to contact our Tech Support team. They can walk you through the settings on the product and see if there may be a fix. Our toll-free Tech Support number is printed on your invoice, and is also available under the "My Orders" tab in the "My Account" section of our website. If you did not purchase the unit from Crutchfield, then you may want to contact the manufacturer. You can also post your question in our forums: Or try our online support center: [ Krissy  Sep 06, 2016 ]  Staff
Dear John: Thank you for your question about the Boston Acoustics SA1 which Crutchfield forwarded to me. I am not sure that I fully understand your question, but I may give you some usable information to reach a conclusion. I have two SA1's in two home theaters. One has been driving a Snell subwoofer in a Snell in wall array which is nominally rated at 6 to 8 ohms for almost two years. The other is driving a second generation pair of Technics THX subwoofers in accordance with the original Technics directions which have these two subwoofers wired in parallel. The Technics subwoofers wired in parallel are connected to a single output on the SA1 and have a total nominal impedance of four ohms when wired in parallel across the SA!'s output terminal. The SA1 driving the Technics has been in place for perhaps ten years. Before I bought the SA1, I had discussion with Boston or Snell (Snell had been purchased by Boston) and was assured that the SA1 could easily handle a four ohm load, which it has here for about a decade. If you are asking if the SA1 can easily drive a two ohm load, I really do not know and would be reluctant to do that with any home subwoofer amplifier without speaking with the manufacturer or better yet, getting something in writing regardless of the stated specification. It has been years since I spoke to anybody in Boston and Snell is now defunct, but their customer service was very, very good and the people I spoke to knew their products very well. I believe that Boston is still selling a passive subwoofer (in-ceiling?) which uses the SA1, so there must be somebody left who has thorough knowledge of the SA1. If possible, please have the Crutchfield people let me know what you end up doing. While the SA1's build quality is no match for the ultra high end, it s a very good product and has been extremely reliable. If there are quirks, even after a decade of use, I have not found them. Jerry [ JEROME  Aug 23, 2014 ]
I believe the answer is yes. I have 5 of these units installed, however I am only driving single coil subs in each application. The unit drives both outputs identically, so I would think from the SA-1's perspective it would think it is simply driving two 4 ohm subs. The amp is great, and applies a curve to bass output to properly accentuate lower volume levels. [ michael  Aug 22, 2014 ]