Hi malcolmfrary
Yes the bottom ends are closed , and the speakers are on separate channels . Does any body know if there is some padding that can be put in the tubes ?
Thanks Paul
Papier mache egg box pieces and fibreglass loft insulation spring to mind. I've also used dense foam carpet underlay for the same job. Either will cut internal reflections in the small cabinets that have been made. For deep, throbbing bass without using the modern HiFi techniques of pre-distorting the signal to make a small speaker sound like a big 'un, a big box is needed, much like Stavros has arranged.
Whenever cabinet padding is used, efficiency suffers. With domestic HiFi, this is relatively unimportant since its easier to reduce the efficiency of the rest of the system to match, then use a bigger amplifier to get the required volume because the thing is powered from the mains. With battery power on a boat, this is not usually an option.
A full set of connections does exist between source and amplifier input? Just a thought, since a disconnection or wrong value of capacitor in between the source and amplifier input can act as a high pass filter, remove the bass and give a tinny effect. Again, if the same sound if being presented through each speaker, watch out for phasing.