I’ve built several loudspeakers in the past including a rather large pair of pre-line chambered transmission-line loudspeakers and a sealed enclosure subwoofer. I was blown away by the sound from the TLs, especially the bass. However, they were just too big and ugly. That inspired me to build a subwoofer and perhaps use my Tannoy M2s as front speakers. You can see the sub I made on the White Noise Audio website actually. Unfortunately I was rather skint at the time so I just used a cheap 12” woofer, which didn’t come with any t/s parameters, so I had to guess the enclosure size. I put the amp made from White Noise Audio bits (MOS250 power amplifier, active crossover unit, capacitor input power supply, cascode power supply, 500VA, 2x50V ac transformer ,30VA, 2x25V ac transformer) on an aluminium plate on the back of the sub at the time basically because it was the cheap option.
Well now that I’m a rich PhD student (*cough*) I’ve decided to have another bash. This time I’ve made a case for the amplifier (using the same components as before) and added a White Noise Audio loudspeaker protection module. I’m sure it’s not quite up to dad’s standards and will no doubt have far less cable-ties but it works very well none the less. This also means if I decide to make another subwoofer I won’t have to worry about integrating an amp. I’ll post some pictures here.
As for the sub, this time I’ve made a 34.1L ported enclosure and used a top of the line Vifa PL22WR0908 8” bass driver, which has a cast magnesium chassis. Since I’m still living in a flat (with smallish rooms) and moving around a bit I’ve focused on trying to make a modestly sized sub with a good bass response. According to Brian Steele’s Ported.xls v1.7 and Kristian Ougaard’s UniBox v4.05 enclosure modelling (free) software, 34.1L is the optimum ported box size for this Driver, giving an Fb of 31.47Hz and an F3 of 33.56Hz – which sounds good to me. I’ve made the actual box (18mm MDF) now but am waiting to receive a double flared port (to reduce port turbulence) and some ash wood veneer etc to finish the box. I’ll probably have it finished this week so I’ll post some pictures soon and let you know how it sounds when I fire it up.
