If you need assistance with your order, this website, or any of our products, please call us at 1-800-262-4675.

    0

    Your Cart is Empty

    Products
  • AHB2 Power Amplifier Black

    Power Amplifier

  • HPA4 Headphone Amplifier Silver

    Headphone Amplifier

  • LA4 Line Amplifier Silver

    Line Amplifier

  • DAC3 Digital to Analog Converter Silver

    Digital to Analog Converters

  • REL Subwoofers with AHB2 Power Amplifier

    by John Siau November 05, 2020 3 min read

    REL Subwoofers with AHB2 Power Amplifier
    Benchmark AHB2 Power Amplifier

    Many Benchmark customers are using their AHB2 power amplifiers with REL subwoofers. This application note shows how to connect one or two AHB2 amplifiers to one or two REL subwoofers using the speaker outputs on the back of the AHB2 amplifiers.

    Benchmark AHB2 Rear Panel

    Benchmark AHB2 Rear Panel

    AHB2 Rear Panel Connectors and Controls

    The MODE switch in the lower right-hand corner sets the AHB2 to stereo or mono mode. In stereo mode, the outputs of the AHB2 are conventional unbalanced outputs. In mono mode, the output of the ABH2 is balanced.

    The two red binding posts (1+ and 2+) on the AHB2 are driven by the amplifier outputs. The black terminals (1- and 2-) are the ground returns for each of the two channels. We will use one of these speaker ground returns as a connection point for the REL ground wire. Notice that the SpeakON connectors provide access to the same set of outputs. In stereo mode, the left speaker is connected between 1+ and 1- using the binding posts or the SpeakON connectors. The right speaker is connected between 2+ and 2-.

    Notice that the 1+ post is labeled M+ and the 2+ post is labeled M-. These are the outputs for mono operation. The speaker is connected between M+ and M- using either the binding posts or the SpeakON connectors. In mono mode, M- is an inverted version of M+.

    REL "Baseline Blue" High-Level Input Cable

    REL Baseline Blue High-Level Input Cable

     

    REL supplies a cable with yellow, red and black wires that connect to the speaker output terminals on a power amplifier. The SpeakON connector plugs into the back of the REL subwoofer. The yellow and red wires deliver speaker-level inputs to the REL, but draw no power from the amplifier. The black wire is a signal ground reference for the speaker inputs. The yellow and red inputs are summed together in the REL. This summing allows the input of a left and right channel which will be summed to a single subwoofer. The yellow, red and black spade terminals will need to be connected to the binding posts on the back of the AHB2 power amplifier. We recommend connecting your speakers to the SpeakON connectors on the back of the AHB2 while reserving the binding posts for the REL cable.

    Please read these instructions carefully because the yellow, red and black connection assignments will vary according to one of the following system configurations:

    System Configurations

    Caution: Never connect the REL BLACK wire to a RED binding post on the AHB2. This will short the output of the AHB2 ground and put it into protection mode. It could also damage the REL subwoofer.

    One Stereo AHB2 amplifier feeding one REL Subwoofer

    • AHB2 1+ to YELLOW (left input)
    • AHB2 2+ to RED (right input)
    • AHB2 1- to BLACK (ground input)
    • Set the AHB2 MODE switch to STEREO

    One Stereo AHB2 amplifier feeding two REL subwoofers

    • AHB2 1+ to YELLOW and RED of Left REL sub (left input)
    • AHB2 1- to BLACK of Left REL sub (ground input)
    • AHB2 2+ to YELLOW and RED of Right REL sub (right input)
    • AHB2 2- to BLACK of Right REL sub (ground input)
    • Set the AHB2 MODE switch to STEREO

    Two Mono AHB2 amplifiers feeding a single REL subwoofer

    • Left AHB2 M+ to YELLOW of REL sub (left input)
    • Left AHB2 1- to BLACK of REL sub (ground input)
    • Right AHB2 M+ to RED of REL sub (right input)
    • Note: It may be necessary to extend the RED wire if the left and right amplifiers are not stacked.
    • Set the AHB2 MODE switches to MONO on both amplifiers.
    • Caution: Do not make any connections to the M- binding post

    Two Mono AHB2 amplifiers feeding two REL subwoofers

    • Left AHB2 M+ to YELLOW and RED of Left REL sub (left input)
    • Left AHB2 1- to BLACK of Left REL sub (ground input)
    • Right AHB2 M+ to YELLOW and RED of Right REL sub (right input)
    • Right AHB2 1- to BLACK of Right REL sub (ground input)
    • Set the AHB2 MODE switches to MONO on both amplifiers.
    • Caution: Do not make any connections to the M- binding post

    Final setup

    Adjust the level of the REL subwoofer by turning the control on the back of the unit.

    Additional Information

    https://rel.net/how-to-connect-my-rel/


    Also in Audio Application Notes

    Closeup of Plasma Tweeter

    Making Sound with Plasma - Hill Plasmatronics Tweeter

    by Benchmark Media Systems June 06, 2023 2 min read

    At the 2023 AXPONA show in Chicago, I had the opportunity to see and hear the Hill Plasmatronics tweeter. I also had the great pleasure of meeting Dr. Alan Hill, the physicist who invented this unique device.

    The plasma driver has no moving parts and no diaphragm. Sound is emitted directly from the thermal expansion and contraction of an electrically sustained plasma. The plasma is generated within a stream of helium gas. In the demonstration, there was a large helium tank on the floor with a sufficient supply for several hours of listening.

    Hill Plasmatronics Tweeter Demonstration - AXPONA 2023
    While a tank of helium, tubing, high voltage power supplies, and the smell of smoke may not be appropriate for every living room, this was absolutely the best thing I experienced at the show!
    - John Siau
    Read Full Post
    Benchmark AHB2 Power Amplifier

    ChatGPT Reviews the AHB2 and Includes Listening Impressions!

    by John Siau June 02, 2023 2 min read

    What happens when you ask ChatGPT to write a review?

    I asked ChatGPT to review the Benchmark AHB2, and I was shocked at the results!

    It turns out that ChatGPT wrote a review by gleaning information from the many publicly available reviews of the AHB2. I recognized phases and sequences of words that had appeared in prior reviews, and yet the text was new, original, and well written. The ChatGPT review seemed to summarize the collective impressions of the reviewers without directly quoting any particular reviewer.

    It should be possible to ask ChatGPT to write a review on any well-known product and the result will be an AI-generated review that reflects the collective opinions of many human reviewers.

    These AI-generated reviews may be more useful than traditional search results!

    If I am not mistaken, ChatGPT seems to have golden ears!

    Here is my dialog with ChatGPT:

    John Siau PFP

    John Siau:

    Write a review of the Benchmark AHB2 complete with listening impressions.

    chatGPT logo

    ChatGPT:

    Title: Unleashing Sonic Purity: A Review of the Benchmark AHB2 Amplifier

    Introduction: The Benchmark AHB2 amplifier has gained a reputation for its exceptional audio performance and unwavering dedication to sonic purity. In this review, we delve into the heart of this powerhouse amplifier, exploring its features, design, and most importantly, the listening impressions it evokes...

    Read Full Post
    ChatGPT Logo

    ChatGPT and John Siau Discuss Star-Quad Cables

    by Benchmark Media Systems May 30, 2023 7 min read

    Today, Benchmark's John Siau and OpenAI's ChatGPT had a conversation about star-quad cables. It turns out that ChatGPT got quite a few things wrong, but learned quickly when these errors were pointed out by John Siau.

    ChatGPT is quick to recognize mistakes, and quick to provide detailed corrections. In each of the first few corrections, additional errors were made. As each of these were pointed out, ChatGPT began to provide accurate information.

    Here is my conversation with ChatGPT: 

    John Siau PFP

    John Siau:

    How do star-quad cables reject interference?

    ChatGPT logo

    ChatGPT:

    Star-quad cables are designed to provide improved rejection of ...

    Read Full Post