[ Home | Staff & Contacts | DIY & Tweaks | Listening tests | HiFi Playground | Music & Books ]

September 2009 Editorial

Bookshelf loudspeakers: most wanted ever???

Author: Lucio Cadeddu - TNT Italy

[Seated bookshelf] Once upon a time there were just loudspeakers. They used to be big, obtrusive, heavy and ugly as hell. They were so big it was impossible to place them on a different place than the floor, and nobody really cared whether the tweeter was exactly at the height of a seated listener's ear or not. Good old days, as nobody really cared about 3D imaging and virtual soundstage at all. Then AR (Acoustic Research) started to design and sell smaller boxes and, all of a sudden, the HiFi market changed radically. Audiophiles or, more precisely, music listeners, couldn't believe they were really going to place their speakers anywhere, possibly in a hidden place. WAF ruled even during the good 'ol days :-)
The bookshelf loudspeaker was born. It took almost a decade to realize that bookshelf loudspeakers sounded better if placed on speaker stands. Slowly, bookshelf loudspeakers became freestanding speakers, freestanders or standmounts.
The major benefit of bookshelf speakers vanished: audiophiles started to use speaker stands that costed more than the speakers themselves! The floor, once free from speakers, became the ideal place where to install bookshelf speakers. Funny as it may appear, the vast majority of bookshelf loudspeakers, nowadays, is placed on the floor (via expensive stands and, possibly, spikes). Am I alone feeling this is a pure nonsense? Once you have room enough for a speaker stand you have room enough for a small floorstanding loudspeaker!
What's worse is that nobody makes good bookshelf speakers anymore! They are called bookshelf speakers but they should be installed on stands for better performance.
[Human bookshelf]

So, let's get back to the problems a bookshelf loudspeaker causes when installed where it should be, right inside a bookshelf.
First of all, the bookshelf itself, depending on its structure, tends to sound, excited by the loudspeaker vibrations. The higher the listening level, the worse the effect. This adds colourations and distortion. Moreover, a speaker placed close to the rear wall (as it happens on most bookshelves) gets a boost in the bass and mid-bass region while the midband becomes harsh and confused because of early reflections comimg for near walls and shelves.
Of course, all of these things destroy soundstage and virtual imaging. Finally the reflex port, if of the rear-firing kind, might limit the possibility to place the speaker very close to the rear wall. Are these troubles really unavoidable?
Can we design speakers that are meant to be installed on a bookshelf and still sound decently? Of course we can.
The boost in the bass and mid-bass range can be calculated a priori (approximately, of course) and kept into consideration when designing the loudspeaker. Just make it a little bit bass shy in free air, so that it'll become linear when placed close to the rear wall. Linn and Naim speakers used to be designed this way.
Vibrations and resonancies. Something can be done by decoupling the speaker from the bookshelf, via soft rubber feet of more sophisticated devices (even a floating cabinet might be a solution). As for bass reflex troubles, let's place the port in the front baffle or directly in the bottom of the cabinet, so that the acoustic load remains pre-determined by the designer.
Oh, let's not forget soundstaging...well, we can happily live even without it, since it is a thing that rarely can be experienced in live concerts.

I believe loudspeakers designers should start building REAL bookshelf loudspeakers again, as the market strongly needs these. Especially here in Europe the average size of flats or houses - hence rooms - is becoming smaller and smaller so it is compulsory to place the speakers on a bookshelf or on some other piece of furniture. The floor is quickly becoming off-limits. We receive dozens of letters of audiophiles who ask for real, good quality bookshelf loudspeakers. I think it's time to give 'em an answer. Real world speakers for real world audiophiles. C'mon, it shouldn't be all that difficult.
Since true perfection has to be imperfect, perhaps we should start...little by little:

True perfection has to be imperfect
I know that that sounds foolish but it's true
The day has come
And now you'll have to accept
The life inside your head we give to you
You know I didn't mean
What I just said
But my God woke up
On the wrong side of his bed
And it just don't matter now
Cos little by little
We gave you everything
You ever dreamed of
Little by little
The wheels of your life
Have slowly fallen off
Little by little
You have to give it all in all your life
And all the time I just ask myself why
You're really here
[Oasis - Little by little]

© Copyright 2009 Lucio Cadeddu - www.tnt-audio.com

[ Home | Staff & Contacts | DIY & Tweaks | Listening tests | HiFi Playground | Music & Books ]