When I had the big transmission line speakers (see olderprojects) I never needed a sub woofer. However when I switched to the JM-labElectra 906 speakers, the need for a sub was evolving. The Electra's produceenough for stereo, but I missed the 25 hz rumble of explosions in DVD's.


This is what I had in mind:


Remo sells the excellent AC10-SW8 andpartnered with the DT-150 power amp, this shouldbe a fine combination.

These combinations were possible :

  Liter -3Db tuning Port diameter (cm) Port length (cm) amp bass boost
AC-10 SW8 40 28 30Hz 7 20.8 none
AC-10 SW8 35 28 30Hz 7 11.3 +3db/30hz

The idea is, that if I start with a passive subwoofer of 40 Liters, Iplace the 20cm tube.

If i decide to make it active, the power amp takes 4.5 liters, and itautomatically becomes 35 Liters. Simply replace the 20.8 cm tube with a 11.3 cmtube. The performance will be about the same.

So here it is, I tried to match the looks of the Electra line, so the designis a bit more complicated than normal. The design (as a word document) can befound here. The scan of the original drawing canbe found here.


Center speaker 2002

I have build a center speaker during summer 2002, to match the W cone basedElectra 906 I bought.


The "old" one

The new 5W3211B units are partnered by the TC90td5b

The new center on the test bench

I have made calculations by using ls-prof. This made a 19 Liter cabinet, witha 3.5 diameter port. The length of the port would be 3,85 cm.

The filter is still in test stage. The one on test right now is not verysatisfactory. so there is still work to be done. Here is an example of themeasurement of the tweeter.

het filter as test

In 2005 I changed my equipment rack to a quardaspire rack. I also had changed my Remo Rogers Monitor to Jmlab's Electra series. I descided to take the current speaker apart and build a new cabinet.

The new cabinet in its raw form on build

The cabinet is now painted, has its side panels on and the tweeter mounted

The final product on its new place

A more recent picture of the setup


Older projects

In the pas years, I have build a lot of speakers. I started with the homeconstructors from REMO

This was on of the first .The woofer(AD 80652) and tweeter (AD 11600/T8) were new units. The mid unit was a used one.I was amazing what you could do with the units. They were also used in Philips popular designs. But with proper tuning they sounded way better than the original Philips designs.


A bigger picture

I had some of the units recently, but they were falling apart because of age.This is a common problem with Philips speakers fron this age. The edges are made out of foam and they fall apart after about 15 years. So I threw them in the dustbin.

The last one was a design done by Remo. The advantage is that is was a kit,so only glue them together, and use some nice veneer wood to make the jobcomplete.

This is the Rogers monitor 5.0 Eventually replace by the JM-lab Electra 906. Isometimes miss the sound, but not the size :-)


Below Remo's midi line, build for a friend of mine.


here a larger version

Links :



JM-lab en focal




  Eelco van Vliet, 2008