How does it sound inside a loudspeaker?

Horror of horrors.


But first how does it sound outside of a loudspeaker box?


A Beyer M55 omnidirectional 500Ω moving coil microphone was used as a probe.


Signal path:


Interlude - Siouxie, Morrissey from YouTube - iPad mini headphones out - Pleiades Auratone type 5C speakers - handheld Beyer M55 mic as sound probe - Sony TC-D5 Pro as preamp- Sennheiser HD 580 headphones


The Pleiades Autatone 5C type speakers are made of 3mm carton box. Uncoventional as it may seem the sound is quite good to the outside world listened by ears with enough bass. It may be the case that with a thick wooden enclosure even more sound would be trapped inside. More investigation needed. Very thin wooden enclosure has not been tried yet. Porous absorbing material had been removed from existing setup as it felt it made the sound worse.


The Sony mic in attenuation pad switch was used to toggle between acoustic sound and sound through setup.


Mic in front of speaker.
Nice sound a lot of treble too.


Mic at other positions of front side.
Bad but not objectionable midrange only.


Mic towards sides:
Bad midrange.


Mic towards top side.
Some bass only?


Mic towards back side.
A lot of deep bass like a sub.


Mic towards base.
Does not apply as speaker is standing on table.


When the box back lid was opened mic was first inserted and the lid then closed again.
Only very deep bass.


Mic inside and back lid open.
Horror of horrors mid bass, midrange only.


It is felt that common porous materials may be unless at such bass, mid bass frequencies as their wavelengths are huge compared with the thickness of the materials.


Spaced from the sides membrane absorbers like those used inside recording spaces or studios in order to absorb or convert to heat low frequency content have not yet been tried except some described on an earlier post but membrane was relatively thick. The thin box sides may play the role of absorbing internal bass revebaration. Bass did not sound bad. Midrange was much more problematic. Would spaced from sides (so as to absorb the wave before it falls on sides) very thin membranes do the trick of absorbing it?



Neither bonded or glued thin membrane absorbers have been tried yet on the box sides.


Neither as mentioned a very thin wooden enclosure.