Which of these alignments would produce more robust, clean, flat performance, mostly for HT. It will be a non-corner-loaded application. Sub will be located behind sofa. Up to 1000W available. Disregard port constraints. They are not an issue. Only ported suggestions, please.
volume,Fb
a.)140l, 22HZ
b.)160l, 20HZ
b.)180l, 20HZ
c.)220l, 18HZ
e.)"here's my suggestion"
Driver is an HE-15
Qts .326
VAS 3.768ft^3
Fs 29
Re 1.5 Ohm DVC
Le 3.7
xmax .9 inches, 23 mm
Z 2.0 Ohm
Qms 6.0
Qes .345
SPL 89.42
Pe 2000W
Bl 13.5
Dd 11.92
Sd 740cm^2, 111.6 in^2
Thank you to all who model it.
volume,Fb
a.)140l, 22HZ
b.)160l, 20HZ
b.)180l, 20HZ
c.)220l, 18HZ
e.)"here's my suggestion"
Driver is an HE-15
Qts .326
VAS 3.768ft^3
Fs 29
Re 1.5 Ohm DVC
Le 3.7
xmax .9 inches, 23 mm
Z 2.0 Ohm
Qms 6.0
Qes .345
SPL 89.42
Pe 2000W
Bl 13.5
Dd 11.92
Sd 740cm^2, 111.6 in^2
Thank you to all who model it.
I kind of like the blue curve in both cases. It seems to be a good compromise between BW extension and damping.
OK, I walked straight into that. Hold on! I mistated. 
I DO have port constraints, and they are going to require a volume of at least 140 l at these Fb's.
So nothing under 140l, and nothing tuned over 24HZ, sorry.
Again, will not be on a wall or corner, just direct radiating.
Thanks
I DO have port constraints, and they are going to require a volume of at least 140 l at these Fb's. So nothing under 140l, and nothing tuned over 24HZ, sorry.
Again, will not be on a wall or corner, just direct radiating.
Thanks
JMO but I'm into alignments that support room gain and are
tuned to interface with room modes. As room modes are 1/2
wavelenth = room length you can easily work them out.
v sound =1120ft/s, consider a room 20ft x 14ft x 9 ft.
1st modes are 28, 40, and 63 Hz, a nicely shaped room.
(Double them , they don't overlap then triple....)
In this case at slight dip around 28Hz and a peak below
28 Hz, at around 20Hz will work well with the room.
For smaller speakers a port tuning of around 33Hz would
work well with this room, the 28Hz mode defining the cutoff.
Port frequencies of around 28 Hz and 40Hz should be
avoided in this room.
I'd say your 180/19 would work best in this room.
🙂 sreten.
tuned to interface with room modes. As room modes are 1/2
wavelenth = room length you can easily work them out.
v sound =1120ft/s, consider a room 20ft x 14ft x 9 ft.
1st modes are 28, 40, and 63 Hz, a nicely shaped room.
(Double them , they don't overlap then triple....)
In this case at slight dip around 28Hz and a peak below
28 Hz, at around 20Hz will work well with the room.
For smaller speakers a port tuning of around 33Hz would
work well with this room, the 28Hz mode defining the cutoff.
Port frequencies of around 28 Hz and 40Hz should be
avoided in this room.
I'd say your 180/19 would work best in this room.
🙂 sreten.
Well, I believe you are already aware of Thomas W's project with the HE 15 or the Blueprint 1503, (the two were much the same).
Here is the link for a project very similar to this, except for the Powerport thing.
http://www.diyaudio.com/forums/showthread.php?threadid=999&highlight=
Judging from the measurments, I would estimate Thomas W's internal volume to be about 6 Ft³, or 179 liters.
Why not just copy his design as much as possible, except fo the Powerport thing? His is already built, and it works.
Here is the link for a project very similar to this, except for the Powerport thing.
http://www.diyaudio.com/forums/showthread.php?threadid=999&highlight=
Judging from the measurments, I would estimate Thomas W's internal volume to be about 6 Ft³, or 179 liters.
Why not just copy his design as much as possible, except fo the Powerport thing? His is already built, and it works.
ThomasW is helping me over on his forum. He has always been very candid and helpful.
WinISD gives me a port length that is 4 inches longer than the CarStereo port calculator or the Unibox derivation. Which of these programs is more accurate?
WinISD gives me a port length that is 4 inches longer than the CarStereo port calculator or the Unibox derivation. Which of these programs is more accurate?
Not sure which is more accurate.
One question. Have you tried shortening WinISD's length to the Unibox length and see how much Fb goes up? I suspect it won't be by much.
I would suggest installing the longer length then cutting back. You can always check tuning frequency by running an impedance test and taking the point of lowest impedance.
One question. Have you tried shortening WinISD's length to the Unibox length and see how much Fb goes up? I suspect it won't be by much.
I would suggest installing the longer length then cutting back. You can always check tuning frequency by running an impedance test and taking the point of lowest impedance.
I think WinISD does not correct for port termination, as the others seem to. Since powerport doesn't really afford the convenience or simplicity of cutting the port shorter, due to it's complexity, I will just make a guess that the shorter lengths are more accurate, though I am not sure that the powerport termination requires end corrections. Hmmm
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