Our showroom - speaker choice

Most home cinema sound systems in this country won't even reach 'Level 1 - conveys artistic intent' in the upcoming CEDIA/CTA RP22 design guidelines, which Owen is on the working group for.

Most often, it's because they used hi-fi speakers, designed for music and wrong for cinema. They just don't have the dynamics or sensitivity to reach the levels of a real cinema, unless you have several hundred watts of amplifier power - and you probably can't, because there's not enough budget.

In practice that means the system doesn't go loud enough - so you turn it down during loud passages, because it's distorting and sounds harsh. That means you can't hear the words clearly during quiet bits, so you either turn it back up again, which spoils the illusion, or you give up and do something else.

Even worse, buyers then assume they 'don't like loud' - loud isn't the problem, the problem is that you were mis-sold a mismatched system by a so-called expert.

Most systems sold in the UK are specified pretty randomly - 'is it in budget?' and 'do I make good margin on it?' being the key considerations for many install firms. It's a mix of historical ties to a few companies, laziness, and profiteering.

We didn't want that for our showroom so we''ve used Klipsch speakers throughout - 3x THX-504L at front, 6x THX-502L at front wide, surround, and surround back, with 2x Pro-1200SW subwoofers and 4x Pro-16RC overhead in a 9.2.4 Dolby Atmos configuration

What is THX?

THX Ltd was started by George Lucas and Tomlinson Holman in 1983, when 'Return of the Jedi' was released - they were frustrated at the poor sound quality available in cinemas and even on film sets.

THX logo

THX evolved to become a set of exacting quality standards for commercial and domestic cinemas alike, as well as the mixing rooms that ultimately became Skywalker Sound (now owned by Disney) - one of the very best audio production facilities in the world.

Not all speakers that are right for the job will be THX certified - but every THX certified speaker definitely is

The tests for THX certification ensure that speakers achieve reference level without distortion (hence why room size is critical), that off-axis response is smooth, which helps everyone in the off-centre seats, and that the frequency response is level and accurate, so that the playback is just as intended by the director.

If a speaker is being sold for home cinema use, and hasn't passed the THX tests, why not? Can your provider give you accurate SPL calculations for the space? Does the speaker suffer from comb filtering? What about off-axis response? We do all these checks as standard when we design your system.

Klipsch THX-504L loudspeaker

The Klipsch THX series speakers - or any other THX certified speakers -  don't have this problem - it's been independently assessed that they go loud enough, have the right frequency response and the right dispersion to give true cinema performance in rooms of the right size. The higher 92dB/W/m sensitivity of the 504-L and 502-L speakers also means they go louder without distorting, even when used with real-world amplifiers.

I was also reassured by Klipsch's pedigree across a mix of hi-fi, commercial cinema and home cinema systems.

The recommended level for all cinemas - domestic or commercial - is 85dB of SPL plus 20dB of headroom. We exceed that spec comfortably, with power in reserve. Just like a high-powered car - whether petrol or electric - having plenty of power in reserve gives you a real 'effortless' feeling.

It's also important not to go too far the other way - too much loudspeaker sensitivity often means you can hear amplifier hiss or other noise during the quiet sections.

After narrowing down to just a few makes that would work for our room, we went with Klipsch THX, as they have the effortless performance we wanted, and offer excellent value for money.

Typical but wrong placement

Thanks THX Ltd for this explainer image.

The THX Performance Classes

A common misconception is that there's a quality difference between the THX classes for home cinema - Compact, Select, Ultra and Dominus.

In fact, these different tiers are only about room size and viewing distance (we explore these differences in What does a Home Cinema Cost?)

The experience will be the same provided the correct level is used, for example it's not advisable to use Select speakers in a Dominus sized room, or vice versa.

Compact - for small rooms ~28m3 and viewing distances ~2.4m

Select - for room volumes approx 57m3 and viewing distance 3m (such as our demo room)

Ultra - for rooms around 85m3 and viewing distance 3.6m

Dominus is the newest THX certification, for very large domestic rooms - volume 184m3 and viewing distance 6m.

We can build you a better home cinema - with the best speaker choice for the space and your needs. Let's talk about it.