loudspeakers and your room
I feel that the role of the loudspeaker in any given room is largely underestimated. Many users aren't getting anywhere near the most from their loudspeakers due to bad placement or insufficient amplification - both of these issues can be addressed somewhat by choosing the 'right tool for the job'. Whilst all loudspeakers produce music, they do so in different ways, and some of these alternative approaches work better in certain rooms than others.
Most loudspeakers are designed to sound their best in free space, hence the need for them to be clear of room boundaries. Experimentation will cost you nothing but a bit of time. In reality, most people can't or won't give a loudspeaker the sort of floor space in their living environment they really need unless they're lucky enough to have a dedicated listening room. Fully understandable. In this case, choosing a loudspeaker that works better against a wall than others will give you a better sounding system.
sealed cabinets and passive radiators
Most loudspeakers use a reflex port to boost bass and improve efficiency. A port augments bass output where the speaker's bass starts to naturally roll off, making the speaker sound a little stronger in that region than it actually is. The downside to this is a much sharper bass roll off underneath the frequency the port has been tuned to. Loudspeakers using sealed cabinets like some of the Amphion and KEF models don't suffer from this issue, and have a more natural bass response that rolls off slowly, and because of this, actually reach deeper than a ported loudspeaker. The usual downside of a sealed cabinet is a lower efficiency, which isn't really an issue nowadays with the higher powered amplifiers that are readily available.
Some sealed cabinets use passive radiators, something that more and more subwoofers tend to use nowadays. These are extra bass cones placed in the cabinet which are "dummies" - they're not connected to the crossover, so aren't driven by the amplifier, and react to the changing air pressure within the cabinet. While these passive radiators can also tuned to a particular frequency, they respond to a wider frequency range than ports, helping the bass response to sound more natural. KEF use these in their Q Series floorstanders, and Amphion use them in their top three Argon models, just as they do their pro-monitors for studio use. KEF place theirs on the front of the cabinet, whereas Amphion place them on the rear of the cabinet directly behind the working bass drivers, presumably to make the most of the rearward energy from them. This approach avoids the negative issues with ports, some of which are the reason why ports are usually at the rear of the speaker, like escaping midrange and port noise.
In the case of the Amphion Argon 3S, 3LS, and 7LS, the rear mounted passive radiators give a great example of benefits of the passive radiator approach. Firstly, you'll normally find that the nearer ported speakers are placed to a wall, the more the bass starts to become a bit boomy, and quite uneven around the room. Using these Amphion models, the in-room bass response is much more even, which is particularly noticeable when walking around the room, which results in a more natural sounding loudspeaker. This can reduce the need for digital room EQ, and means there's less adjustment by room EQ systems because the in-room response was already better behaved.
digital room correction
Digital room correction will mainly benefit home theatre systems, although it is slowly finding its way onto two-channel hi-fi products. That's not too bad if you have a predominantly digital system, but the analogue-to-digital and digital-to-analogue converting needed for this process isn't necessarily something a music lover might want to introduce into an all analogue system. The other issue is that loudspeaker manufacturers have spent a lot of time and money to produce a product that is as faithful as possible to the original signal. To then use digital room correction to boost or subdue certain frequency issues in the room is fundamentally changing what is supposed to be an unadulterated output from the loudspeaker. This digital correction is intended for a specific listening point too, unless multiple point measurements are taken, which then means the corrected result is then an average of these multiple positions, and is no longer a "perfect" correction.
Would you invite a violinist into your home to play a few tunes, but stop them half way through their first song in order to "correct" the in-room response of their instrument?
using room boundaries
Some tout room correction as a "fix all" solution allowing you to place your loudspeakers against a wall and let the EQ sort out the end result. By doing this, the digital EQ is doing even more work in order to maintain a flat in-room response, and changing the speaker's output even more.
One pretty unique approach is from Swedish loudspeaker manufacturer Larsen. Their research began as Sonab in the 1960s. Their designs aren't developed in an anechoic chamber - after all, who has one of those at home?! Their designs are developed to work with the room's boundaries and walls to produce a very natural sounding loudspeaker that works well against the wall in any room, without needing the space most other speakers need. Due to their room-friendly design, the currently little known Larsen speakers are massively overlooked by those who actually need one of their products!
I have to say, it sounds odd to place a speaker up against a wall and not hear bass boom...
By carefully choosing your system components and minimising room issues, you may only need a bit of physical room treatment, if any at all. HiFi systems were enjoyed by all for decades before room correction came along, and most of those systems had very little thought to positioning paid to them.
Thanks for reading and making it to the end! Feel free to browse the website, email email@example.com or call 0121 638 0721 or 0753 888 1969 for help or to arrange an audition or a consultation. We are a 1 mile walk from New Street Station, or 5 minutes on the Metro system that runs between Broad Street and Wolverhampton.
davidf @ the little audio company