Below is one of the Seas test boxes used by Seas (image provided by Bjorn Idland from Seas with various data measurements). It is an 18L so may not be appropriate for your situation. Notice the replaceable sectional baffle.
This (Courtesy of Bjorn) is the description of the Seas test box:
Box
The box outside dimensions:
Front baffle: 20cm wide and 49.6cm high
Box depth: 29.6cm
Edges are trimmed with a roundover-bit r=12mm.
Driver placement:
Both drivers are centered on the vertical axis.
The distance between the drivers centers are 158.5mm
The distance from the top of the baffle to the tweeter centre: 65mm
The distance from the top of the baffle to the woofer centre: 223.5mm
The box has a removable tweeter baffle. This way we can measure all drivers flush mounted in the same box.
The box is approximately 18 liters and the port tuning is approximately 40Hz. All woofers are measured like this, regardless of what the T/S calculations suggest.
Cheers,
David.
This (Courtesy of Bjorn) is the description of the Seas test box:
Box
The box outside dimensions:
Front baffle: 20cm wide and 49.6cm high
Box depth: 29.6cm
Edges are trimmed with a roundover-bit r=12mm.
Driver placement:
Both drivers are centered on the vertical axis.
The distance between the drivers centers are 158.5mm
The distance from the top of the baffle to the tweeter centre: 65mm
The distance from the top of the baffle to the woofer centre: 223.5mm
The box has a removable tweeter baffle. This way we can measure all drivers flush mounted in the same box.
The box is approximately 18 liters and the port tuning is approximately 40Hz. All woofers are measured like this, regardless of what the T/S calculations suggest.
Cheers,
David.
Attachments
Hi there,
Bjorn is a pretty helpful guy. You might be able to PM him for an answer / to clarify my post:
http://www.diyaudio.com/forums/member.php?s=&action=getinfo&userid=12635
Cheers,
David.
Bjorn is a pretty helpful guy. You might be able to PM him for an answer / to clarify my post:
http://www.diyaudio.com/forums/member.php?s=&action=getinfo&userid=12635
Cheers,
David.
Hi,
We have posted some info about our test boxes on our web page.
See the link on the second line here:
http://www.seas.no/index.php?option=com_content&task=view&id=180&Itemid=175
The box in the picture above was used for a series of measurements we did to aquire data for crossover simulation. This is not a box we use for measurements that go in the datasheets.
Bjørn
Seas
We have posted some info about our test boxes on our web page.
See the link on the second line here:
http://www.seas.no/index.php?option=com_content&task=view&id=180&Itemid=175
The box in the picture above was used for a series of measurements we did to aquire data for crossover simulation. This is not a box we use for measurements that go in the datasheets.
Bjørn
Seas
Hi folks,
just for information purposes, there's (at least in Germany) a so called DIN baffle - which is an open baffle for amplitude-frequency response measurements - with the following characteristics:
size:
width 135cm (approx. 53.15")
height 165cm (approx. 64.96")
the chassis is mounted off-center by the following offsets:
horizontal 15cm (approx. 5.91") (either left or right, doesn't really matter)
vertical +22.5cm (approx. 8.86") (direction to the top)
The influence of the baffle will be +1.0/-1.5 dB above 250 Hz and with up to +/- 2.5 dB deviation measurements down to 40 Hz are possible. The microphone has to be mounted - of course - at a distance of 1 meter (= 100 cm or approx. 39.37") at 0° horizontally/vertically to the driver - which lead to the SPL diagram in dB/W/m.
My plans/drawings are already made with a modular setup for different chassis diameter and a flat baffle mount. Therefore only the smallest possible baffle cut-outs for various chassis' needs to be made once and can be interchanged for all the measurements.
It might be the case that for instance Seas does not rely on that DIN baffle but other manufacturer (besides the german once) do rely on measurements done with this DIN baffle for comparison purposes.
I would wish that only all measurements were taken in the same manner for better comparison - and it must not be necessarily the DIN baffle.
just for information purposes, there's (at least in Germany) a so called DIN baffle - which is an open baffle for amplitude-frequency response measurements - with the following characteristics:
size:
width 135cm (approx. 53.15")
height 165cm (approx. 64.96")
the chassis is mounted off-center by the following offsets:
horizontal 15cm (approx. 5.91") (either left or right, doesn't really matter)
vertical +22.5cm (approx. 8.86") (direction to the top)
The influence of the baffle will be +1.0/-1.5 dB above 250 Hz and with up to +/- 2.5 dB deviation measurements down to 40 Hz are possible. The microphone has to be mounted - of course - at a distance of 1 meter (= 100 cm or approx. 39.37") at 0° horizontally/vertically to the driver - which lead to the SPL diagram in dB/W/m.
My plans/drawings are already made with a modular setup for different chassis diameter and a flat baffle mount. Therefore only the smallest possible baffle cut-outs for various chassis' needs to be made once and can be interchanged for all the measurements.
It might be the case that for instance Seas does not rely on that DIN baffle but other manufacturer (besides the german once) do rely on measurements done with this DIN baffle for comparison purposes.
I would wish that only all measurements were taken in the same manner for better comparison - and it must not be necessarily the DIN baffle.
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