Audio advice from Dominic Baker, Electro Acoustic Engineer Focal-JMLab*

(* Please note the views expressed here are not necessarily those of Focal-JMLab)

Chapter 1. Acoustic Basics

Chapter 2. Choosing Your System

Chapter 3. Subwoofers

Chapter 1. Acoustic Basics

Correction of basic dimensions

It is not easy to correct the height of a room without major building work and therefore expense, so I will concentrate on methods for adjusting width and length that are far more easily achieved.

Too long

An elegant solution here is to build a false wall that can also serve to hide your AV electronics, subwoofer and speakers. The construction needs to be solid - a wooden frame of 2x4” beams closely spaced and crossed with well-fixed plasterboard would be a suitable approach. A screen, with curtains if desired, the electronics – amp, DVD player etc and main, centre and subwoofer can all then be flush mounted within suitably dimensioned cubby holes. High quality in-wall loudspeakers could also be used in such a construction. The result is a very tidy and aesthetically pleasing installation, with only the front baffles of the loudspeakers and subwoofer, the fascias of the electronics and the screen visible. All cables and mains sockets are conveniently hidden from sight as well as the bulk of the audio equipment.

Too wide

The ideal here and a great benefit to the overall acoustic, is to line the sidewalls with bookcases or shelving. You can allocate areas to your DVD collection, CDs, magazines and fill the majority of the rest with books purchased as a bulk lot second-hand. Leaving occasional spaces for pot plants and other ornaments with create a very pleasing effect without affecting the overall acoustic result. It is best to keep the room as symmetrical as possible laterally, so bookcases or shelving should be repeated on both sides.

The random nature of the objects you choose to fill the bookcases/shelves have a very positive acoustic effect. Their uneven nature will help break up the large flat surfaces of the walls and scatter any reflections resulting in a greatly increase soundstage and a more open and natural acoustic.

Just right

Even if your room falls into the ideal ratio, or once you have taken any feasible steps to get closer to this ideal, there is still significant room for sonic improvement. One of the simplest and most cost effective is to place your furnishings to create an acoustic advantage.

Making your room sound bigger than it really is

Our ears and brain form a very powerful sonic analyser. Using the difference in time between the direct sound from the loudspeakers and that reflected from the walls of the room we ‘hear’ how big the room we are within is. So when Clint Eastwood fires his six-shot in a dusty desert scene, we hear that we are not there in the desert with him, but in a room listening to the recorded effect. To open up this sound stage and allow the loudspeaker/audio decoding system to create the correctly corresponding ambience, we need to scatter these fast reflections from our room boundaries whilst retaining the acoustic energy balance within the room.

Achieving this is really quite simple. You will need a helpful friend and a mirror and be prepared to move things around a little. Whilst you are sitting in your normal listening/viewing position, get your friend to hold a small mirror flush against the sidewalls and move the mirror about until you see the image of your left and right loudspeakers. Mark the positions on each wall with some tape. Where you mark the position of the closest loudspeaker to the sidewall, ie. left speaker on the left wall, is the primary, of fastest, reflection point. Where you mark the position of the image of the right loudspeaker on the left wall is the secondary reflection. Most important is the primary. By placing a piece of furniture/tall plant/DVD rack etc here the primary reflection will be scattered or broken up, so your brain looses it’s clue as to how wide the room is and soundstage will widen and become more natural.

The same can be applied to the ceiling to improve height perception, although here I would recommend a RPG Flatfusor. These are very thin acoustic diffusers that are extremely efficient and can be ordered with a wide range of different fabric coverings to suit your deco. One or two of these will cost you very little and will have a positive effect on the acoustic.

Again the same technique can be used to beneficially place a rug on a hard wood floor, preventing floor level reflections.

Controlling bass

If you find that the bass in your room is still coloured or boomy, ie. not as tight or as articulate as you would like, consider adding some nice sofas. These are large, soft structures that will effectively soak up excess bass energy and help clean up bass performance. Rather than having to resort to acoustic tools such as bass traps, a far more comfortable environment can be created in this way.

Final note

I see a lot of dedicated cinema rooms where furnishings are extremely minimalist and walls, floors and ceilings are large uniform areas. This situation does not lend its self to a natural acoustic. The wider the variety of materials used within a room and the more objects that clutter it the better controlled the energy dispersion becomes. Staggering dimensions, combinations of soft and hard surfaces and strategically placed objects to scatter primary reflections will result in a smooth, natural and open acoustic that not only will greatly benefit sound, but is also a more agreeable environment to watch a film or listen to music within. Have a look around your local cinema or theatre next time you are there and you will notice how much effort has gone into breaking up surfaces to create a natural acoustic.

Chapter 2. Choosing Your System

Choosing your audio system (setting it up will follow later)

I’m going to make some assumptions first to simplify things and to ensure that you get the very best from this guide:

1. You are here on this site because you have a CRT projector and do so because you appreciate fidelity/quality, not quantity or specs.

2. You have one room for your AV equipment and enjoy watching films, concerts or just listening to music.

3. You are not yet a millionaire, so want to get the most mileage possible out of your hard earned cash.

Next it is paramount to understand that 5 channels of sound, DVD player, AV amp, subwoofers etc are going to cost you 2-3times more than a stereo hi-fi if you want to maintain the same quality. And I can’t emphasise enough the quality aspect of all this. You will gain far more pleasure watching a film on your DVD player with a £1000 2-channel system than a £1000 5.1 combo. We hear the effects of the centre and rear ‘speakers, but we perceive the quality of the performance by the overall sound quality. So, a 2 channel AV system is where we’re going to start off, then we will work through to a fully blown high-end multi-channel system. Please resist the temptation to skip straight through to the end, even if you can afford to, because you will miss out on some useful information on how to choose you equipment. If you have to, go through the same selection process at a higher speed and you will end up with a top-flight system without making expensive mistakes.

Step 1, a 2-Channel AV system

Initially, the largest chunk of your budget should go towards the DVD player. Its quality will determine what the rest of the system will deliver and it is the single common element feeding information to both the video and audio side. If you are on a really tight budget, the £450 Philips 963SA would be a great choice. It is shortly to be replaced, so deals will certainly be available. Its video is very respectable, but make sure to use the discrete phono RGB outputs that have higher resolution than the RGB available on the scart. Sonically, I’ve A/B’d against players costing 10times the price and it holds its ground very well. It is a touch bright, but this can be tamed with a decent quality interconnect cable. Make sure to turn the ‘upsampling’ on which greatly improves its audio performance.

For a little more money you should be able to get a bargain on the now replaced Denon 2900. Again audio quality is excellent and this player has the advantage of easy conversion for a digital video SDI output. SDI is possible with the Philips, but it’s a lot more complicated. Both are SACD compatible, which is a high-resolution multi-channel music format pioneered by Sony and becoming more and more popular. Even if you don’t have any SACD's at all, your normal CDs will benefit from the higher resolution converters needed for this format. If you can stretch a little further and have a video scaler that will benefit, the replacement for the 2900, the 3910, has an HDMI output.

For the amplifier, loudspeakers and cables, you’ll need to audition quality products at a decent hi-fi store. Try and allocate £300-1000 towards a pair of decent bookshelf loudspeakers, the more the better as they are going to stay with us throughout the evolution of the system. Look for a 6” bass driver + tweeter combination and rigid, stable stands to put them on. This combination is the most efficient form of loudspeaker where the highest performance/£ is available. Resist the temptation to go for a large pair of floorstanders because their more complicated nature means that you will need to spend a lot more to significantly improve on midrange/treble performance. The only advantage will be bass depth and power handling, which will become irrelevant later on in our system’s upgrade path.

The amplifier should be a simple stereo amplifier that has adequate power and enough inputs for all of the sources that you wish to connect. Look at models from Arcam (A65) and Rotel (RA-01 and RA-02) for example. Also allow funds for decent cables. If you find a quality hi-fi store they will let you audition several hi-fi systems until you find something that gives you the sound that you want. Many people are under the misconception that they are not ‘qualified’ to hear the difference between audio systems, which is nonsense. Get an audition, listen to several amp/loudspeaker combinations with your chosen DVD player that fit your budget and that you enjoy listening to. Everyone has different tastes, so the important thing is to find the style of presentation that you enjoy and that pulls you into the music. Cables will have a difference also and can effectively be used to fine tune a system. For example, you may find a combination that has fantastic detail and resolution, but is a touch bright tonally. A good hi-fi store will be able to advise on a suitable interconnect cable/loudspeaker cable that will tame this and give you the best of both worlds.

Take along music that you know and judge you choice primarily on midrange/treble performance. The bass quality and quantity will be dealt with later on in the evolution of your system but the loudspeakers will still figure in the system, so the mid/treble quality is paramount.

Don’t worry about the lack of a centre channel or surround loudspeakers too much as a quality system well selected will be capable of placing a vocal image centrally and creating a very convincing atmosphere/ambience with just two loudspeakers.

Step 2 – a 2.1 AV system

Next step is to add a subwoofer. The reason I chose to make this the next step is that it will teach you how to set up a subwoofer to get deep, tight, tuneful bass that doesn’t boom or colour the rest of the system. We could have added the centre, surrounds and an AV amplifier to drive them, but there is too much scope for taking a step backwards in quality.

The subwoofer is also going to stay with us through the evolution of the system, so donate as much budget as you can, £500-1000 would be suitable. Arrange to borrow several subwoofers from a good hi-fi store and audition them at home with your own equipment – any decent store will be happy to arrange this. Your room will have a very strong influence on the performance of the subwoofer, so this step is essential. Connect the subwoofer to the pre-out sockets of your amplifier and then adjust the frequency and level controls, starting at their lowest setting until you find a seamless integration with your main loudspeakers. You should not notice that there is a subwoofer in your system until you turn it off. Play a wide range of music that you know and listen to the bass quality, not quantity. You are looking for a deep, tight bass that plays tunes, not booms strongly at the same frequency. Use a dedicated subwoofer interconnect cable that will have additional screening and reduce the chances of picking up mains hum - a very annoying 50hz drone.

Step 3 – finally we’re going multi-channel!

I would strongly advise 5 channel systems, not 6 or 7. The vast majority of your DVDs will have been mastered in 5-channel, so let’s concentrate on dealing with these 5 original channels properly. 6 and 7 channel systems often use electronic trickery to fake in the extra channels and although can work extremely well when perfectly set-up, can complicate things unnecessarily. If we accurately reproduce the 5 original channels then your system will be capable of tricking you into turning your head every now and again to follow the action, which is the true audio cinema experience. Sadly this is rarely the case due to poor set-up and equipment choice.

*Tip – use the same make and model bookshelf loudspeaker as you have already selected for the stereo pair as the centre channel and surround loudspeakers. There are so many reasons for doing this that space will not allow me to go into all of them, but here’s just a few, if I can decide where to start. . .

1. With a stereo pair of quality loudspeakers we can create an ‘image’ of the performers across a stage positioning them in space to create a realistic reproduction of the performance. This is because they are identical so will work together to create this sonic picture (technically this is down to their phase and dispersion characteristics). With 5 loudspeakers this gets a lot more complex, because if we now want to accurately position the performers/actors etc within your room for a convincingly realistic reproduction, we need to hold a stable image between the centre and right loudspeakers, right and right rear loudspeakers, right rear and left rear, left rear and left main, then left main back to the centre loudspeaker. You have no chance in hell of doing this if you use one brand’s main ‘speakers with someone else’s centre and another brand of rears.

Some manufacturers go to extra lengths to ensure that all of the loudspeakers in a particular range are phase matched, so you can use floorstanding mains with a landscape centre channel and slim rears. But it is surprising how many still have not thought about this and applied it. Unless you can guarantee this, don’t take the risk and use 5 identical loudspeakers.

2. The majority of landscape centre channel loudspeakers have two mid/bass drivers either side of the tweeter. As you move off to one side of the loudspeaker, because the distance between you and each of the two mid/bass drivers is not equal, they start to cancel each other out and you loose midrange level and detail – not at all a good thing for a centre loudspeaker where the majority of vocal information in a film-track comes from. If you are watching a film with friends and family seated either side of you they will hear a worse vocal quality and lower level than you in the centre, which is a little selfish! In addition the dispersion of the centre channel is vertical and not in the same plane as the main loudspeakers that have the tweeter mounted above the woofer and have a horizontal dispersion. They won’t seamlessly integrate across the front stage and ‘image’ precision will be compromised.

3. You have a CRT, so a landscape format centre channel loudspeaker is not necessary – they are this shape so that they can be placed above or beneath a TV.

Hopefully this is enough to convince you. . .

So we’ve sensibly added 3 more of the same loudspeakers and we have a 100% sure chance of being able to hold a solid, stable 3D image. Now we need an AV amplifier to drive them. At this stage of the path, let’s go for a quality AV receiver. Denon, Marantz, Pioneer and others make very advanced AV amplifiers that will get us into the world of multi-channel for £500-2000. Don’t worry about having all of the latest gismos, last year’s top of the range model will always outperform this year’s mid-price model – remember we want to concentrate on accurately reproducing the 5 original channels as well as we can, no more, no less. Keep it simple and you’ll have far more chance of achieving an outstanding system without wasting money.

Now that we have the AV amplifier we can also improve the way we drive the loudspeakers to improve power handling and clarity. Set the amplifier’s loudspeaker setting to ‘small’ (some will allow the user to define the frequency) to remove the bass from the 5 bookshelf loudspeakers and direct it to the subwoofer. Because the woofer in the bookshelf loudspeakers does not have to work as hard to displace large amounts of air in the bass, it will behave in a more linear fashion with lower distortion and greater clarity. In addition, the reduced load on the bookshelf loudspeakers, because they are no longer playing bass, will mean that we will increase our power handling – we can play louder and clearer. It should now be clear why we choose bookshelf loudspeakers with the best quality midrange and treble we could afford.

We can possibly also gain some quality, or more accurately, preserve detail better, by making a digital connection between the DVD player and AV amplifier. The digital connection allows the amplifier to directly access 5.1 channels of digitally encoded signal as intended at the mastering stage. With 2-channel stereo recordings or SACD, for which our DVD player is equipped, best results may still be had via the analogue connection. Compare them carefully before deciding which connection is best for film and music.

Step 4 – Final steps

To get more out of this system is now going to start to demand a more serious investment. A second subwoofer will help even out bass throughout your room. You may have noticed that with a single subwoofer that you have areas where bass is strong, deep and punchy and other parts of your room where bass is lacking. A second subwoofer well placed will fill in these weak areas and give an even bass throughout your room. Because there are two, they are each working half as hard, so are in a more linear part of their operation and bass quality will improve. Power handling also increases.

A dedicated processor is now going to be essential if you want to resolve every last bit of detail and move your system up to a higher level. A separate processor/power amplifiers have many advantages, separating the small signal pre-amplifier stages from the large signal power stages being one. Large transients that put the power supply under pressure won’t now affect the earlier stages that deal with the processing of the audio signal. There will be less interference that smaller signals are particularly prone to. Dedicated processors will provide more sophisticated options for set-up that will allow you to unlock more of your system’s potential. These can include algorithms to compensate for loudspeakers placed at non-ideal distances and angles, user programmable frequencies for subwoofers/main loudspeakers, gain matching so that all sources are the same loudness at the same volume setting, etc etc. There will also be an increase in sound quality due to the high-resolution digital and analogue stages used in a higher-end processor. It really is the audio hub of your system, as your scaler will be the video hub. Good examples include models from Lexicon, Theta Digital and Meridian .

As an initial step you could use a dedicated processor whilst still using the power amplifier stage of your AV amplifier, but as soon as possible, this should be replaced with a dedicated multi-channel power amplifier or multiple stereo/mono power amplifiers.

Cables can be fine tuned to get the very best out of the system – remember that a system of components is only as good as its weakest link. So a poor cable in a high-end system will strangle it.

Important Note:

Find a quality hi-fi store that you are confident with and trust and stay loyal to them and they will help you through the process of building a system, select suitable and matching products, arrange demonstrations, allow you to trade in your equipment as you upgrade and save you money and provide a top-quality service. You might save a few £s internet shopping, but you will more than likely loose out in the long run.

Note from Henry @ CRT: You will find we can offer the kind of service required to build the very best AV system!

Subwoofers

Correctly used and set-up, the addition of one or more subwoofers to a system can make the whole home theatre experience that much more impressive and enjoyable. However, there are many traps and often the boomy drone that results from a poor set-up can be detrimental, rather than beneficial. So here in this article we’ve going to start with a basic 2.1 set-up first (stereo speakers with a single subwoofer) and only when comfortable with the results and how to properly use a subwoofer will we develop to more complicated and, ultimately, higher performance solutions including some that you may not have come across before. As in articles before, please follow through the steps of building up a system as they will prove valuable instruction when you come to finally set-up your 7.4 mega system. Skipping to the end section will not make the most out of the aim here. I’m going to stick to 5 main channels for the descriptions, 6 & 7 can be dealt with in exactly the same manner.

The History of the LFE channel

To understand how the subwoofer came to be a part of our home theatres and how to use them effectively, it is important to know a little of the history of the LFE (Low Frequency Effects) channel. The LFE channel was first introduced into movie theatres. Originally, the full range loudspeakers being used in cinemas were considered more than adequate for the material being played. However, with the demand for greater dynamics and power in the bass to deal with action movie ‘explosions’ it was decided that the most economical way to upgrade the sound systems in thousands of cinemas worldwide was to add a separate LFE channel to the film and suitable amplification and loudspeakers to the theatre. The idea was that cinemas could keep their existing loudspeakers and just add a ‘subwoofer’.

Films now carried the extra LFE channel that contained all high level bass signals that were deemed too powerful for the original loudspeakers. So the original installations remained and all ‘effects’ considered too powerful were encoded into a separate LFE channel and dealt with in the cinema by a dedicated, high power ‘subwoofer’. It was decided that these LFE channels should carry the additional effects content below 120Hz – something important for us to bear in mind when we are considering a home theatre system.

Placement

Let’s take a moment first to dispel a common myth: subwoofers, generally, should not be used in the corner of a room. Nearly every manufacturer recommends corner placement for their subwoofers in the user’s manual. The reason is that in this position bass is boosted by wall reinforcement and for the same volume level (on the subwoofer, relating to how much power its amplifier provides to the driver) bass is stronger. Because the subwoofer has to work less to deliver more, there is less chance of the customer blowing it up.

Unfortunately, because the subwoofer is placed in a corner it driver the room modes most efficiently and bass becomes boomy and uneven – bass quality suffers. For better bass quality place your subwoofer in the middle of a wall, front or sides are normally best if just one subwoofer is being used. Do be aware though that you may need a larger, higher power subwoofer or two subwoofers to safely achieve the levels you desire.

2.1

Here we are going to play a CD in stereo with the main left and right ‘speakers configured as large and with the subwoofer connected to the stereo line-out main left and right phono sockets (left and right main pre-amp outputs). In this configuration, we are going to use the subwoofer to subtly extend the bass response of the main loudspeakers. The main ‘speakers should be in their normal left and right positions and the subwoofer in-between them as close to the centre of the wall as possible.

Choose a couple of tracks from different albums and different styles of music each with a good wide range of bass on them, low, mid and upper bass and listen through them initially with the subwoofer off. Start with the subwoofer set at its lowest crossover frequency, normally around 40Hz and with the volume as low as possible. The trick now is to slowly increase the volume until you only just hear the bass from the subwoofer at your listening position. A second person can be a great help during set-up. Next you want to increase the crossover frequency until you feel it meets smoothly with the main ‘speakers. Too high and there will some overlap causing a boost in level and an unevenness in the way bass scales are played. Be aware that with many subwoofers the crossover and volume controls will affect each other, typically increasing crossover frequency will increase volume also.

It may take several hours of listening and tweaking to get to a perfect result. What you should aim for is a system where you can’t hear the subwoofer at all, but only notice that it was working when you turn I off. This is where the subwoofer is perfectly integrated into the main ‘speakers. This is a valuable lesson in subwoofer set-up: if you want your system to perform in all situations with all types of material, then the subwoofer needs to be an integrated part of the system. The result will be extended hours of pleasure. A subwoofer that can be heard over the rest of the system is impressive at first, but will quickly become fatiguing.

5.1

Here we have a choice to make. We can run the main ‘speakers as ‘large’ and deactivate the subwoofer in stereo mode using the ‘LFE only’ (this means that your AV amplifier will only send a signal to the amplifier when a DVD is played) option of the amplifier for stereo music, or, set the main ‘speakers as small and use the ‘both’ setting so that the subwoofer is active during films and stereo music. This is not as simple a decision as it may at first seem, as a lot will depend on the facilities your AV amplifier has to offer and how well it has been designed (see separate section on ‘The history of the LFE channel’).

‘Small’

If you have followed my previous articles, you will hopefully be sitting in front 5 (or more) of the same bookshelf loudspeakers. In this case, we will select small and use the subwoofer for ‘both’ LFE and stereo music. If the amplifier is doing its job properly, it will be removing the bass from you ‘small’ loudspeakers below, for example, 80Hz and directing it to the subwoofer for both stereo and multi-channel music/film. Some amplifiers allow you to choose the frequency where this happens, some decide for you. If you have followed the previous article and have 5 or more quality bookshelf loudspeakers in you system, 80Hz is a good frequency to aim for. Here power handling will be significantly improved because of the reduction in bass that they are being fed. But 80Hz is still low enough to cover the whole vocal range and deliver directional punch.

Now when an LFE channel is detected, such as would be the case with a Dolby Digital or DTS soundtrack, the LFE information, typically 120Hz and downwards, will also be directed to the subwoofer. If you don’t want some of this information to be lost, it is important that you connect to either a dedicated, unfiltered LFE input on your subwoofer, or set the crossover frequency to 120Hz or higher. If you had set the crossover frequency on your subwoofer to 90Hz, the LFE information between 90Hz and 120Hz would be filtered out by the subwoofer and lost.

The volume level should be set first using stereo music by adjusting the volume on your subwoofer with the ‘sub level’ on your amplifier set to 0dB. We normally like a little more impact from the subwoofer when in film mode which is done by setting the LFE level on your amplifier to the desired setting. Some amplifiers will have a global setting, some will allow individual LFE level settings for Dolby Digital and DTS, it depends on the model and price range.

‘Large’

If you have selected ‘large’ because you have floorstanding loudspeakers as mains, you will need to select ‘LFE’ only on your amplifier. Your amplifier has no way of knowing how deep your loudspeakers can go, so to integrate the subwoofer perfectly with your floorstanders for stereo music you would have to use the crossover control on the subwoofer. Because they are floorstanders, you would likely end up with a crossover frequency of 50Hz or lower. The problem with this would be with a soundtrack containing LFE information; everything between 50Hz and the 120Hz upper limit of the LFE signal would be lost.

So, with ‘large’ and ‘LFE only’ selected you can go ahead and set the volume on the subwoofer with the sub level on your amplifier at 0dB.

5.2 v1

The next step up from a 5.1 system is to add a second subwoofer. You may notice that with one subwoofer that you have an inconsistent level of bass throughout your room, that is, the bass is louder in some places than others where it seems to almost disappear. A second subwoofer can usefully fill in these gaps for a more even and natural bass throughout the whole room. In addition, each of the two subwoofers will need less power than one single sub, so will be working in a more linear, lower distortion part of their range.

The ideal position would be in the middle of the sidewalls either side of your listening area. Here the subwoofers are close to you so less power will be required, but in addition the bass timing will be improved. Because of the boost often incorporated in the amplifier and driver, subwoofers tend to have quite a long signal delay compared to the main loudspeakers, typically relating to a distance of 5m/15ft or more. Your ear is not extremely susceptible to these delays, but a slight improvement can be had. A centre front wall and centre rear wall position would be the next best choice.

5.2 v2

With two subwoofers there is another system configuration that can be used to enable correct use of a subwoofer with ‘large’ main loudspeakers when playing stereo music as well as LFE content soundtracks. The first subwoofer is connected as in the description above ‘2.1’, so is fed from the stereo line-out sockets of your amplifier and set-up to integrate smoothly with your main loudspeakers. The second subwoofer is fed by the ‘LFE’ or ‘Subwoofer’ output of the amplifier that is configured as ‘LFE only’.

Now when you play stereo music, only the subwoofer that has been smoothly integrated works to assist your main loudspeakers to dig a little deeper into the lowest octaves. With a soundtrack containing a LFE signal, this subwoofer continues to assist you mains, but the second deals with the explosions. It’s an elegant solution for someone who wants the best out of both 2.1 music and 5.1 soundtrack worlds.

5.4

Considered to be the ultimate, 4 subwoofers give an even, powerful, low distortion, effortless bass performance. Here the subwoofers would be ideally positioned in the middle of each of your four walls, front, rear, and sides. It is what I am running in my system, however I must say that the gains over a twin subwoofer system are really quite small. Two subwoofers are maybe twice as good as one, but 4 are only a fraction better than 2 in my opinion. Unless you have a very large room, a dedicated theatre room or limitless budget, it’s probably not worthwhile considering.

Phase, not a blind art

I’m going to tackle the whole phase setting in subwoofers in a separate article and at a later date. For now, follow the recommendations of the manufacturer in the manual provided with your subwoofer. Setting phase accurately is critical to accurate and tuneful bass, but it’s such a complex affair, really requiring some measurement equipment, that it needs to be dealt with separately. I also need some time to track down a suitable and affordable system so that I can detail the technique clearly and in a way that has some real value.

We are most grateful too Dominic Baker for his professional insight. More will follow.

© Dominic Baker 2005

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