When some people think of a subwoofer they likely imagine one that occupies the whole boot of a small souped-up car, with a “DOOOF DOOOF DOOOF” so powerful it startles pedestrians and sets off car alarms as it goes past.

In hifi it’s very different, the key is: a subwoofer should not be the component you hear the most in a system - actually you should hardly hear much of it at all, but you should definitely feel it.

The REL S/510 cranked up!

The Home Cinema bit

It’s easy to appreciate the impact of a subwoofer in your home cinema system, adding excitement to action films, adding more depth to atmospheric background noises or more drama to cinematic scores.

The Audiophile bit

Adding a sub to a 2 channel system currently seems to be more popular in the US than in Europe, but audiophiles are starting to catch on here too. We believe a subwoofer can bring a stereo system to life! A well set-up sub seems to add depth and clarity to the midrange of your existing stereo speakers no matter the size.

A subwoofer only lets you know it’s there once it’s been switched off - you’ll really notice the difference in the sound. Its main job is to underpin the sound of your main speakers with those lower frequencies, so what you hear sounds ‘fuller’.

How Low Can You Go?

Or more importantly, how low does our music really go? Bass notes are made up of a fundamental pitch, plus complex overtones and harmonics that give a note character and allow us to identify the instrument that created it.

In the old days of acoustic instruments in contemporary music, the bass player struggled to be heard over the drummer and the horn section. The advent of the Fender Electric Precision Bass Guitar and amplification in 1950 allowed the lowest bass notes to be heard much more clearly. A four string electric bass is usually tuned E, A, D, G with the fundamental frequency of the low E string at approximately 41.2 Hz when tuned to concert pitch.

In the early 1970s electric bass player Anthony Jackson tuned his Fender Jazz bass down to a low C. You should check out his amazing bass lines on Chaka Khan’s early solo albums and also with Steve Khan’s Eyewitness Band. He then commissioned luthier, Carl Thompson, to create a 5 string bass tuned BEADG, and later a 6 string “contrabass” tuned BEADGC, the low B having a fundamental frequency of 30 hz.

A 6 string bass alongside a rel subwoofer

Some genres such and metal or electronic music use even lower notes than this, some classical music has thunderous bass notes that makes an orchestra sound huge.

What Hi-Fi? have written an article specifically listing the best tracks for testing bass, which you can find here.

REL Subwoofers

REL Acoustics LTD was founded in 1990 by Richard Edmund Lord, on the basis of his dissatisfaction with the performance of available subwoofers at the time. By 2005, John Hunter and Donald Brody had taken over. Find out more about their chronological timeline and products here.

The evolutionary key element of the subwoofers’ design is the high input level, which came about from the design idea from Silicon Valley of more power and better performance with natural sound filtering. They also use musical instrument grade bracing on cabinets for a controlled bassline.

REL subs have very low latency even when using their Arrow wireless system… The quicker the drive unit moves, the tighter the bassline sounds. And it’s not just about how quickly a note starts, the timing of where the note stops is equally important with bass players often using space between the notes to create a groove.

REL Subs have two inputs: a high level input that is piggybacked off your speaker terminals using a special cable (provided) and a line level input. Each input has a volume setting for maximum flexibility.

Sub Optimal Placement…or optimal sub placement?

Low frequency sound waves become problematic when their wavelength starts to coincide with the dimensions of your room. This causes the sound to either cancel out at certain frequencies, or to combine and produce resonant notes. This will also result in an uneven bass response, with some parts of the room bass heavy and other areas completely lacking. If your listening position happens to be in one of these nulls then turning up the bass isn’t going to make any difference, it may even make the problem worse!

One trick to is to place your subwoofer in your listening position and then place yourself in various locations around the room until you find a spot where the bass sounds great…. that’s probably where your subwoofer should ideally go. It does however involve crawling around the room, so maybe wait until you’ve got the house to yourself, family members probably wouldn’t understand.

Although, let’s be honest, they probably already don’t understand.

The optimal placement for your subwoofer will often be very different to the optimal position for your main speakers, with subs near a wall or in a corner and the main speakers away from walls where possible.

Placing your full range speakers can often be a bit of a compromise between bass coherence versus soundstage, adding a sub you can allow you to make fewer compromises with your main speaker placement.

Sub Settings

Before experimenting with levels and crossovers it’s important to listen with the phase switch in each position, you want your sub to be working with your speakers and adding to the sound. If the sub is out of phase it will likely cancel out some bass, and not in a predictable way, one position will sound clearly better.

Crossover frequency

This controls the cut-off point of the sub and will depend on how deep your main speakers will play, you want enough overlap so that basslines don’t drop out at certain frequencies, but not too much that you get a bass hump.

Conclusions

While it may take a few hours to initially set your sub up for best results, and you may spend a few weeks making small adjustments, it’s definitely worth the effort.

Why not try it for yourself. Give your local Audio T store a call to find out more information about the products listed, and if you’re just passing by, why not pop in and take a look at them too?!

Thanks for reading!

Richard & John – Audio T Enfield

If you have any questions about any of the equipment featured in this article, or any other Hi-Fi or home cinema enquiries, be sure to Contact Us.

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