mattkhan
Distinguished Member
I built a sub in Mini sub for computer system to go under a desk so now I need some speakers to go on the desk to complete a 2.1 setup. The constraints here are;
- they will be positioned fairly close to the wall
- must be narrow (maybe 10cm or so), can be fairly deep, are preferably quite tall with the driver nearer the top
- need to extend to ~100Hz or so to allow a clean handover to the sub
- don't need to go beyond 90dB at 1m at this is a desktop system
The width constraint places a hard limit on the size of the driver to probably 3" and so I've decided to try my hand at a full range speaker to avoid having to stuff a crossover into a tiny box & because a 2.5-3" driver is used in quite a few full range designs. These often seem to be transmission lines so I've decided to go down this route and build a mass loaded transmission line (MLTL) which is basically a TL with port.
The drivers are 2½" SB65WBAC25-4 :: SB Acoustics which look like this in real life, mug of tea for comparison. Tiny little things!
I'm using Transmission Line v3.6.3.5 | Leonard Audio for modelling purposes which is a really easy to use piece of software, shame it's not maintained anymore but it seems to do the job nicely.
My current design is a tapered folded MLTL which gives a response like
first attempt at folding
I need to revise this though as I hadn't really accounted for the path length along the bends and I think there might be a better way to maintain the line length and driver/port positions while fitting it into a box.
Here's the line itself with driver (D) and port (P) positioned marked
I'm not sure if a TL is really worth it over a port but I figured that modelling a quarter wave design & learning about folding is probably a good thing to learn about
- they will be positioned fairly close to the wall
- must be narrow (maybe 10cm or so), can be fairly deep, are preferably quite tall with the driver nearer the top
- need to extend to ~100Hz or so to allow a clean handover to the sub
- don't need to go beyond 90dB at 1m at this is a desktop system
The width constraint places a hard limit on the size of the driver to probably 3" and so I've decided to try my hand at a full range speaker to avoid having to stuff a crossover into a tiny box & because a 2.5-3" driver is used in quite a few full range designs. These often seem to be transmission lines so I've decided to go down this route and build a mass loaded transmission line (MLTL) which is basically a TL with port.
The drivers are 2½" SB65WBAC25-4 :: SB Acoustics which look like this in real life, mug of tea for comparison. Tiny little things!
I'm using Transmission Line v3.6.3.5 | Leonard Audio for modelling purposes which is a really easy to use piece of software, shame it's not maintained anymore but it seems to do the job nicely.
My current design is a tapered folded MLTL which gives a response like
first attempt at folding
I need to revise this though as I hadn't really accounted for the path length along the bends and I think there might be a better way to maintain the line length and driver/port positions while fitting it into a box.
Here's the line itself with driver (D) and port (P) positioned marked
I'm not sure if a TL is really worth it over a port but I figured that modelling a quarter wave design & learning about folding is probably a good thing to learn about