How to Bi-amp Your Speakers

How to Bi-amp Your SpeakersIt may sound like a complicated process, but with the right equipment, bi-amping your speakers is very simple indeed.

In this short guide, we’re going to describe why you should bi-amp your speakers, and describe how to do it.

Why Bi-amp Your Speakers?

Many home cinema speakers come with four sets of terminals on the back, two red, and two black with each pair of terminals supplying separate high and low-frequency signals to the correct speakers. When supplied, the speakers will usually have a ‘bridging plate’ across them so that you only have to supply one cable to the speaker. If you supply each pair of terminals with a separate cable, from a separate amplifier output, you will be ensuring that each frequency gets a dedicated and consistent signal and this should improve the sound quality.

How to Bi-amp your speakers

Firstly you need to make sure that your home cinema amplifier and speakers are capable of bi-amping. Most modern 7.1 home cinema amplifiers (such as the Onkyo TX-SR607) are suitable for Bi-amping, but check your instruction manual to make sure. If you are already using all 7.1 channels, then you will have used up all your outputs so this isn’t an option for you, but otherwise, read on.

  • Obtain more cable – If bi-amping is possible, then all you need is an additional length of speaker cable for each of the front speakers – you can buy dedicated bi-wire/bi-amp speaker cable such as the QED Bi-wire if you want to keep everything neat or take the opportunity to replace or upgrade your cable. Otherwise, just buy an additional two lengths of speaker cable – preferably of the same brand and type as the existing cable, and try keep to the same length if possible.
  • Connect to the outputs on your amp – If you read your instruction manual you should see which terminal on the amplifier you need to connect the new cable to – it is often the rear back surround outputs (used on a 7.1 set up) – and simply connect them up. If you are using standard speaker cable it is a good idea to label the cable at this point so you know which one is which.
  • Connect to speaker inputs – Then, you’ll need to remove the bridging plate from the speakers and check which cable needs connecting to which frequency input. Your speaker inputs should have the letters HF and LF next to the appropriate inputs. so simply re-connect the original cable to the inputs specified, and the new cable to the other pair.
  • Enable your amplifier – Then you need to go into your set up options and change the settings as described in the manual. On the OnkyoTX-SR605 for example you simply change the speaker type from ‘normal’ to ‘bi-amp’.
  • Recalibrate your system and enjoy! – Whilst not absolutely necessary, it is probably best if you run the calibration program again (if your amp came with one) to make sure everything is sounding as good as possible. Then all that’s left is to pop a few of your favourite discs on and enjoy the difference!

Bi-amp Speaker Terminals

Is it worth Bi-amping your speakers?

Like many things in audio and home cinema, the effects of improvements such as these can be very subjective. However, the physical evidence of supplying a different frequency from a different feed does stack up and we have noticed very worthwhile improvments when implementing it on sets up in the past. Because you will only bi-amp your front speakers this normally only requires a relatively short length of additional speaker cable, and the worst case is that you won’t notice an improvement – but for such a low cost upgrade, we would say it is definitely worth a go.

1 Comment

  1. Stephen Clayton says:

    With the Onkyo TX-NR107, if I bi-amp the front speakers and set the amp to bi-amp, what signal is sent through to the SURR BACK PRE-OUT. If it is the SURR BACK signal, can I use the PRE-IN of another amp to send it to the rear speakers?

    Thanks for any help.

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