I haven't started building yet, working up to 12hrs per day so not much time for building really...
But I had a listen at a pair of Transmission Audio M3 speakers today. Bass-like I want to achieve something like them. They were powered by a Primare I32 amplifier.
We played the song Stimela (Coal Train) with Hugh Masekela at insane volume and they kept control throughout all the song and the bass was nice (although a little too much in that small room, about the same size as my room). The M3 had two 7" woofers per speaker and I think that might be enough, in a transmissionline that is...
But I had a listen at a pair of Transmission Audio M3 speakers today. Bass-like I want to achieve something like them. They were powered by a Primare I32 amplifier.
We played the song Stimela (Coal Train) with Hugh Masekela at insane volume and they kept control throughout all the song and the bass was nice (although a little too much in that small room, about the same size as my room). The M3 had two 7" woofers per speaker and I think that might be enough, in a transmissionline that is...
adjusting group delay and things...
Anyone model an aperiodic enclosure (i don't have the capabilities on my iMac...)? I suspect that the bass will get tighter and "quicker". This has become one of my faves. The thing is if one has a vented enclosure, things can be tightened up and in my mind improved, with but a few straws or an old pair of (clean) socks or make your own "Variovent" as per Scanspeak. Ever VB that I have tried that I don't like becomes quite palatable after this seemingly dumb fix.
A nice side-effect is that the impedance of the driver drops and the curve smooths out significantly at its resonant frequency. The overall load to the amplifier becomes less, so more current is available at lower frequencies (and therefore "headroom")
Not sure if this is directly related to the newest discussion here...sorry if I'm side-tracked.
Anyone model an aperiodic enclosure (i don't have the capabilities on my iMac...)? I suspect that the bass will get tighter and "quicker". This has become one of my faves. The thing is if one has a vented enclosure, things can be tightened up and in my mind improved, with but a few straws or an old pair of (clean) socks or make your own "Variovent" as per Scanspeak. Ever VB that I have tried that I don't like becomes quite palatable after this seemingly dumb fix.
A nice side-effect is that the impedance of the driver drops and the curve smooths out significantly at its resonant frequency. The overall load to the amplifier becomes less, so more current is available at lower frequencies (and therefore "headroom")
Not sure if this is directly related to the newest discussion here...sorry if I'm side-tracked.
I'd reduce the aspect ratio of that slot a little - you might end up with it not-acting-like-a-port-any-more at higher volumes when the wind starts (30mm isn't much). As a preliminary test, carry right on.
Along which axis will the port be bent?
(its really hard to get this into words) If it's bent so that the 290mmm bit ends up curved, it could end up problematic as there's a large length difference between the longest and smallest paths.
If the 30mm bit ends up curved, the different made will be so small that I wouldn't worry about it, just make sure everything's rounded nicely.
In short, could you post a quick sketch of the slot port?
Cheers
Chris
Along which axis will the port be bent?
(its really hard to get this into words) If it's bent so that the 290mmm bit ends up curved, it could end up problematic as there's a large length difference between the longest and smallest paths.
If the 30mm bit ends up curved, the different made will be so small that I wouldn't worry about it, just make sure everything's rounded nicely.
In short, could you post a quick sketch of the slot port?
Cheers
Chris
Which program is that?
IIRC xmax i 9mm. I know this because there was a guy on a Swedish forum who had a lot of these drivers and he opened one just to see xmax. I don't know about vc length and magnetic gap length...
I have one extra driver which is broken (doa, scrapes when cone is moving), maybe I can "open" it somehow and measure myself?
oops, my Bad.
Here's a calculation I did with an online calculator...I just used this:
Area of a vent:= π X r², and Area of a rectangle:= L X W
equating them becomes: π X r²= L X W
isolating for r------> r²= (L X W)÷π -----> r=√((L X W)÷π)
so using L=3, W=29 the result is as follows : r=5.2624cm
so the 3 cm X 29 cm rectangular vent is the same as a circular vent with a radius of 5.26 cm, or a diameter of 10.52 cm.
Here's a calculation I did with an online calculator...I just used this:
Area of a vent:= π X r², and Area of a rectangle:= L X W
equating them becomes: π X r²= L X W
isolating for r------> r²= (L X W)÷π -----> r=√((L X W)÷π)
so using L=3, W=29 the result is as follows : r=5.2624cm
so the 3 cm X 29 cm rectangular vent is the same as a circular vent with a radius of 5.26 cm, or a diameter of 10.52 cm.
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