Getting the best from your custom installation speakers

Architectural speakers are a great alternative to traditional Hi-Fi speakers for modern living, and can sound every bit as good. However it's important to understand the differences between Hi-Fi and architectural speakers in order to maximise their performance. In this article we'll discuss the correct way to install your speakers, and setup your equipment to achieve the best possible sound quality.

Testing Speakers Before Installation

This is a classic mistake, and we'll go into the reasons why shortly. But please do not make a judgement on your speakers performance by connecting them to an amplifier and sitting them on your coffee table! Even the best in-ceiling and in-wall speakers will be significantly compromised by this sort of testing.

Open or Closed

A speaker drive unit is the component that actually compresses the air to create sound, but in reality it's only part of what makes a speaker's sound signature. Hi-Fi speaker cabinets may look like boring boxes simply there to hold the speaker drivers, but that's a long way from the truth. A significant amount of development goes into speaker cabinet design. This is because a speaker driver produces sound in two directions, from the front of the cone, but also from the back. As a speaker moves in and out it increases and decreases the air pressure in both directions. Speaker cabinets are specifically designed to utilise their air volume and the changing pressure to boost performance. This is done in various ways, and we aren't going to discuss the mechanics of speaker cabinet design here, but the most important thing to understand is that the air volume surrounding the back of any speaker is critical to its final performance.

The majority of in-ceiling and in-wall speakers are open-backed, meaning that the main driver is exposed at the rear and the speaker has no built-in enclosure. This is primarily due to the fact that a speaker with a 'cabinet' attached would be impossible to install into a ceiling or wall void in the majority of cases. A few models do have compact rear enclosures, but these can only be installed where void depth allows. Most integrated speakers are open-backed to aid installation in a range of constructions.

The Goldilocks Zone

As discussed, speaker drivers perform at their best when enclosed by a specific volume of air. When installing a typical open-backed in-ceiling or in-wall speaker into a construction void, this void will act as an acoustic enclosure, and actually become the 'cabinet'.

Construction voids are usually either very open (such as pitched roof spaces, open floor voids, or suspended ceilings), or the exact opposite and crammed full of insulation. Open-backed speakers do not like either. An installation void which has too much air volume, or one which has too little, will both restrict a speaker's performance. In both cases the effect on the speaker is similar, and results in a reduction in bass performance, making the speaker sound light and thin.

To make the speaker perform as it was intended, the air volume needs to be 'just right', and this can be achieved by enclosing the back of the speaker in a couple of ways.

Fire Hoods & Sound Enclosures

To provide the speaker with the right air volume for maximum performance, it is typically necessary to install some form of enclosure behind the speaker.

Solid sound enclosures made of steel, concrete or MDF can be used to create a physical solid cabinet within the ceiling void. While these provide the ideal volume of air, they can only be installed pre-construction, and must be fitted to roof timbers prior to the installation of a plasterboard ceiling.

For 95% of installations, either new build or retrofit, the best solution is to use fire & acoustic speaker hoods. Fire hoods are fabric bags which fit over the back of the speaker. They contain intumescent material designed to expand and seal a speaker hole in the event of a fire to stop its spread. Fire hoods are a building regulations requirement for any speakers fitted below habitable spaces or in areas of escape. But fire hoods also have other benefits. Acoustic models help to reduce sound transfer to adjacent rooms. They prevent debris falling onto the back of the speaker driver which can affect performance. And importantly, they create a semi-sealed volume of air around the speaker, which will help improve sound quality, especially in large open voids like roof spaces and lofts. Even if fire hoods are not required for building regulations, we highly recommend them for the majority of installations, purely for their acoustic benefits.

Speaker Locations

When it comes to locating your speakers, every installation is different and there's no specific right or wrong. However there are some guidelines you should follow. I'm going to concentrate on stereo music systems here. AV and surround sound systems have more specific requirements, and as such require a more detailed discussion. If you need any assistance with speaker layouts for such a system then please get in touch or take a look at the Dolby website for further information.

Firstly, it may sound simple, but place the speakers evenly in the space to be covered. If you have two in-ceiling speakers in a typical square room for example, then place them a sensible distance apart in the centre to create a good stereo soundstage. If you have a large kitchen/dining area and 4 speakers to cover a space this size, then install them as left/right pairs above each area. Ideally you want to be listening in between a stereo pair, so think more about how you use the space than being regimental with their layout.

Finally, don't worry if you can't install the speakers exactly in the perfect position. Floor and roof timbers, structural steels, skylights, downlights and extraction vents will all restrict potential locations. Fortunately, in-ceiling speakers have a wide dispersion, so they will be effective almost anywhere in the room. Just position them as best as possible to create good coverage.

The only area that it is recommended to avoid is a corner or wall. Like any speakers, architectural models are subject to the 'boundary effect' which can make them sound a little boomy if placed close to a large flat surface. Where possible install speakers at least 50cm from a side wall.

Top tip: If you have a Sonos Amp and your speaker positioning doesn't create the ideal environment for stereo left/right listening (ie. you have an open plan space with multiple speakers covering a large area that you move around in), then you may benefit from setting the Sonos Amp to Dual Mono Mode. This will sum the left and right channels and send the mono output to all speakers, thereby removing any stereo effects and evening out the sound across the space.

Equipment Installation

Most modern amplifiers, such as the Sonos Amp, are thankfully very easy to install and setup, but there are some important things to consider when installing your system which can have a huge impact on performance.

Firstly, let's consider the wiring. Connecting speakers to an amplifier is pretty straightforward.  Typically either 1 or 2 speakers are wired to each amplifier channel (left and right) via 2-core speaker cable. The important thing to be aware of here is polarity. Just like a battery, speakers (and amplifiers) have positive and negative terminals, usually indicated by red for positive and black or white for negative. Cables are usually colour coded in a similar way. The critical thing is to ensure that the positive speaker terminal is connected to amplifier positive terminal, and likewise for negative.

The worst possible scenario for performance is accidentally wiring the left and right amplifier channels out of phase, ie. one channel is positive>positive & negative>negative, but the other channel is positive>negative & negative>positive. This might sound obvious, but it's an easy mistake to make. The result of out of phase channels is that one speaker works against the other. When one speaker driver is pushing out, the other is pulling in. The effect can be devastating on sound quality as the frequencies emitted from the speakers cancel each other out. This often results in a rather hollow sound, a bit like the sensation of noise cancelling headphones which work on the same principal.

Amplifier Settings

Most amplifiers offer some sort of EQ (equaliser) or tone controls. For the purposes of this article we'll talk about the hugely popular Sonos Amp, but other amps may have similar settings.

Architectural speakers can provide fantastic sound quality if installed correctly, but smaller models and installation restrictions could mean your speakers need a bit of help when it comes to bass. Also, it's fair to say that modern music, as well as portable speaker and headphone design has favoured a bass heavy sound in recent years which is somewhat exaggerated from reference studio recordings. As a result, 'proper' speakers which accurately reproduce the frequency range may require some bass enhancement for those who like over-exaggerated bass. So if you do feel that your speakers need some help in this area then EQ could be the answer.

The Sonos Amp provides Bass, Treble and Loudness EQ controls. Bass and treble are self-explanatory, and adjust the level of the high and low frequencies up and down as required. Loudness on the other hand is an EQ preset which increases both the low and high frequencies to exaggerate them. The purpose of this setting is to improve performance at low volume levels. At low volume the human ear is less sensitive to extreme high and low frequencies, so Loudness compensates for this by boosting them to maintain a perceived flat frequency response. While this EQ trick is designed for low volumes, it can help speakers sound more punchy, so it's definitely a setting that's worth a try.  However for better control, consider turning off loudness and boosting the high and low frequencies manually to get the perfect balance for your ears, environment and listening levels.

Speaking of environment, it should also be noted that all speakers will sound slightly different depending on their location. For example, speakers installed in a kitchen which has lots of hard surfaces (worktops, hard floors etc.) will tend to sound brighter than a speaker installed in a lounge or bedroom which has carpets, soft furnishings and curtains. This is is due to soundwave reflections. Hard surfaces reflect soundwaves, whereas soft surfaces absorb them. Reflected soundwaves produce reverberations which fill the room and increase high frequency energy, which has the effect of making treble more pronounced. Therefore, in a kitchen it maybe necessary to reduce the treble slightly.

Sonos also has another trick up it's sleave, but it's not available to all. Trueplay™ tuning is available to those with a Sonos Amp plus Sonos in-ceiling or in-wall speakers, and an Apple iOS device. Trueplay provides room correction which automatically adjusts the EQ for best performance by playing test tones from the speakers to your Apple iPhone or tablet. If you qualify for Trueplay tuning then it's worth making use of it.

Please note: Boosting bass and treble will drive your speakers harder for the same volume setting. Don't expect nightclub levels of bass, and don't be tempted to push them too hard or use extreme frequency boosting. You'll only end up driving them into distortion which causes poor sound quality and risks damaging the speakers. If you really want to 'feel' the bass from your system, then consider adding a subwoofer (see below).

Speaker Settings

In addition to amplifier settings, you may have some EQ controls actually on the speakers themselves. Many speakers feature a high frequency boost/cut switch. Typically this provides +/- 3dB of treble boost/cut, and is designed to help tune the speakers to their environment. So as discussed above, a kitchen might benefit from a treble cut, and a bedroom might benefit from a treble boost. Just remember to select the same settings for every speaker in the room.

Of course all of this is down to personal preference and the unique properties of your room and installation, but before fitting the speaker grilles and resorting to amplifier EQ, it's worth taking the time to tune the speakers themselves with any built-in settings first. Remember, there are no right or wrong answers here. Simply adjust the settings to your personal preference.

Add a Subwoofer

Adding a subwoofer to your system will make a huge difference if you're looking for a very bass heavy sound or enjoy electronic music. Not only does adding a subwoofer significantly boost bass performance, but it will also allow your main speakers to perform at their best. By adding a subwoofer, your speakers will not be sent the very low frequencies which they find more difficult to produce. This frees them up to perform better in the midrange, and will typically go louder for less distortion as a result.

Most amplifiers will allow the connection of a subwoofer in one way or another. If you require any assistance with this then please get in touch. If you have a Sonos Amp then you can very easily add one of their wireless subwoofers to your existing system. The subwoofer can sit in the corner of a room and doesn't require a physical connection to the Amp.

If you like a bit of bass, or feel like your existing speakers sound to light, then adding a subwoofer is a great upgrade.

Don't Drive Them Hard

Your car might have a top speed of say 120mph, but you wouldn't drive it around all day at that speed would you? Even if it was legal! Prolonged high speed would inevitably cause components to fail. The same applies to any speaker system.

Amplifiers are not designed to be run at maximum volume. Just because a volume control has a scale from say 0-100, does not mean that 100 should ever be used. Let's take the Sonos Amp as an example. This has a power output of 125W per channel. This is very high for a typical stereo amplifier. Most Hi-Fi amps would not be more than 50-80W. Different speakers can handle different power levels, so don't assume that your speakers can take 125W, and many won't. Even if your speakers do have a power handling of 125W or more, most amplifiers will run into significant levels of distortion at their upper limit. Distortion is very high energy, and as a result it is incredibly bad for speakers and can easily damage a speaker drive unit or electronic crossover.

Speakers with built-in amplifiers such as portable Bluetooth speakers are designed with volume caps to avoid overpowering, so 100% is deliberately safe. When it comes to separate amplifiers and speakers there are no such caps, so it's important to be mindful that overpowering an amplifier like the Sonos Amp could easily blow your speakers.

Where possible we highly recommend setting a volume limit on your amplifier if one is available. This will prevent any deliberate or accidental attempts to drive the speakers too hard. The Sonos Amp has a volume limiter in the sound settings menu. Set this to an appropriate level for the maximum volume required. Once set, this level will become the new 100%, ensuring that your speakers are protected from damage.

Use a Good Quality Source

Any speaker system, especially a high performance one, is only as good as the quality of the source. If you put rubbish in you'll get rubbish out!

Most music streaming services now offer CD quality or above, but more basic services and content like free internet radio stations still use fairly low bitrate formats. High performance audio systems tend to highlight the poor quality of low bitrate audio more so that cheaper systems, so it's important to use high quality streaming services or high bitrate music files to really maximise the performance of your system.

Give Your Speakers Time to Run In

As odd as it may sound, all speakers need a period of running in to reach maximum performance. Just like a new pair of shoes, the flexible components that allow a speaker driver to move will be somewhat stiff straight out of the box. In the same way that it takes time for new shoes to soften up and feel comfortable, new speakers also need a bit of time to loosen up. When the components are brand new and stiff it can make the speaker sound a little harsh. Running in typically takes 20-30 hours of listening, and it is recommend not to drive them too hard during this period.

In Summary

Follow the advice in this article and you'll maximise the performance of your audio system for many years of listening pleasure. The shift to digital music and hidden speaker systems was historically more about convenience than quality. But we believe that this doesn't have to be the case. And with a bit of knowhow you can have great quality invisible audio throughout you home thanks to the growing range of superb architectural speakers.