Once upon a time on usenet Jim Lesurf wrote:
The term "bookshelf" in this context has come to tend to be used to
mean "small enough to be placed on a bookshelf".

I have a pair of speakers that were sold as Bookshelf speakers by the
manufacturer - Goodmans Mezzo SLs. They're ... 530 x 320 x 250 deep (but do
have their small port on the front baffle). Even back in the 1970s when they
were made "bookshelf" was a very loose term that had very little to do with
an actual bookshelf.

From a review in the March 1975 issue of Gramaphone:
"The Mezzo SL is described as a bookshelf speaker, but is moderately large
for such a description, measuring 21 x 12i x 10 inches."

Putting a boxed speaker close to a wall generally boosts the bass
output. Using an open port into free air also generally boosts the
bass output. Thus a designer might design the speaker to use one
effect *or* the other, depending on if the user chooses to place it
against a wall or not.

That same review says this of the Mezzo SL:
"Connections are made via, a recessed box which helpfully carries both a
standard 2-pin polarised DIN male socket and a pair of 4mm (banana plug)
sockets. The recess allows the speakers to be placed flat against a wall,
and such positioning is likely to give just the level of natural bass lift
which bookshelf-size speakers appreciate."

Cheers,
--
Shaun.

"Humans will have advanced a long, long way when religious belief has a cozy
little classification in the DSM*."
David Melville (in r.a.s.f1)
(*Diagnostic and Statistical Manual of Mental Disorders)

So it may be that they had more "tech knowledge" than you think. OTOH
it may have been a clueless / fashion choice on the part of the maker.

Jim

In article , Brian Gaff
wrote:
I bought some fairly cheap bookshelf two unit speakers, and they
sound fine as long as they are at least a couple of foot away from a
wall as they have a port in the back of the cabinet. However they
are described as bookshelf design, and of cours as most bookshelves
are on walls this somewhat makes the port at the rear a silly
design. Not only that but they have the keyhole screw head retainers
and recessed terminals so you can hang them on the wall. Do this and
they sound like portable radios.

This is what happens when those in charge of selling stuff has no
tech knowledge of speaker design! Now if they had made the port in
the side or the bottom.... or the front for that matter! Brian