ARCHIVED FORUM -- March 2012 to February 2022READ ONLY FORUM
This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
TLDR;
I designed replacement parts to bass-reflex-ify RL60s.
https://www.thingiverse.com/thing:3050203 to download the files.
They can be laser cut or mostly cut on a CNC router (there are tight corners that are fit critical that a CNC router won't be able to do. Hand work will be required to finish if cut on a router). If you want to use these yourself the plans are free. If you want to sell these, please talk to me.
The Story:
I got a set of RL60s with a beomaster 3000. They of course had trashed ABRs. at some point an owner had tried to repair them by mounting the ABR plates on speaker grille cloth. which didn't work. No low end at all.
So I came here, and saw the two designs to repair these and the subsequent 60.2 update that used a bass reflex port. I decided to go with the bass reflex design. I drew things up in freecad, which is... well, free. Dunno if any other software can read their format, but I posted a couple formats.
Anyway, the critical part that I haven't yet concluded is how long the reflex pipe should be. For the 1.5" pvc pipe I've got in there right now:
* 3.5" extending out of the 90deg elbow sounds like it's resonating way up at 100hz or higher, which is not good. It's overwhelming.
* 6.5" extension sounds like it's resonating maybe at 30hz? but it's not a huge boost.
These measurements are by ear with a sine sweep from 30hz to 300hz. It's also don in my listening room I could very well have been exciting room nodes, not hearing the speaker itself. I'll try to find a place to do some testing in a less resonant room. I know these are specifically designed to reinforce well in corners, but I don't want a giant lump to deal with.
Also one speaker seems to have some fading caps: the treble is muffled.
Granted, I need give the elbow a 1/4 roundover with a router, and spray paint it matte black on the visible side.