I've seached through TL threads ad nauseum but excuse me if this has been covered before.
I'm currently designing a speaker with the Fostex FX120. Given the Q and Fs, this driver seems to go reasonably low in a standard BR enclosure.
However, given its relatively low sensitivity (for a Fostex) of 89 dB and low max output, I was hesitating to put a standard baffle step inductor on it.
My plan is to use these speakers with a sub crossed around 100hz. In a sealed box they roll off right around 100hz, but baffle step is still an issue.
Given that I don't need full extension, I was wondering if it would be possible to put these in a short (~ 100 hz) transmission line to give a few dB of rise to compensate the baffle step roll off.
I guess the theory here is that the driver output is nearly flat around 100 - 200 hz, where baffle step compensation is needed, so the added output from a short pipe would give a boost in this area.
Given that a TL can give a wide bandwidth increase in output, it seems this might be ideal if a high roll off can be tolerated.
I've modeled this briefly using Augspurger's software (modeled a 100hz pipe vs a 50hz pipe) and there does seem to be a few dB lift in the area where it's needed. It's hard to read his software, however, since it's innacurate for high frequencies (hard to establish a base line output).
In another month or two when I'm on holiday I'm going to cut some pipes and try it out, but I was wondering if anyone here had experimented with this in the past? Any reason it wouldn't work? Anything I should be aware of?
Thanks =)
I'm currently designing a speaker with the Fostex FX120. Given the Q and Fs, this driver seems to go reasonably low in a standard BR enclosure.
However, given its relatively low sensitivity (for a Fostex) of 89 dB and low max output, I was hesitating to put a standard baffle step inductor on it.
My plan is to use these speakers with a sub crossed around 100hz. In a sealed box they roll off right around 100hz, but baffle step is still an issue.
Given that I don't need full extension, I was wondering if it would be possible to put these in a short (~ 100 hz) transmission line to give a few dB of rise to compensate the baffle step roll off.
I guess the theory here is that the driver output is nearly flat around 100 - 200 hz, where baffle step compensation is needed, so the added output from a short pipe would give a boost in this area.
Given that a TL can give a wide bandwidth increase in output, it seems this might be ideal if a high roll off can be tolerated.
I've modeled this briefly using Augspurger's software (modeled a 100hz pipe vs a 50hz pipe) and there does seem to be a few dB lift in the area where it's needed. It's hard to read his software, however, since it's innacurate for high frequencies (hard to establish a base line output).
In another month or two when I'm on holiday I'm going to cut some pipes and try it out, but I was wondering if anyone here had experimented with this in the past? Any reason it wouldn't work? Anything I should be aware of?
Thanks =)