Hi all,
So I just got my Behringer mic for measuring and I wanted to share my findings that I can't quite understand!
I have built two sealed 15 liter cabs for the W6 subwoofer and mic'd it up according to a few tutorials that say as close as possible for indoor measurements. The only thing is that my measurements look NOTHING like my simulated response!
I also stuffed the cabs with 125g of polyfill and as you can see.... NO DIFFERENCE!
Does anyone have any thoughts on what I am seeing? AM I doing something wrong?
Cheers!
G.
PS. Green = no stuffing / Purple 125g of stuffing.
So I just got my Behringer mic for measuring and I wanted to share my findings that I can't quite understand!
I have built two sealed 15 liter cabs for the W6 subwoofer and mic'd it up according to a few tutorials that say as close as possible for indoor measurements. The only thing is that my measurements look NOTHING like my simulated response!
I also stuffed the cabs with 125g of polyfill and as you can see.... NO DIFFERENCE!
Does anyone have any thoughts on what I am seeing? AM I doing something wrong?
Cheers!
G.
PS. Green = no stuffing / Purple 125g of stuffing.
Attachments
You are looking at a 230 dB scale which would make everything look flat. Try changing it to something in the range of 40 dB.
Could you make an overlay of the two curves? That would make it easier to spot differences. It would also be helpful to make a measurement with the woofer turned off to see how much background noise you capture.
Polyfill does not do too much at very low frequencies, though its effect should be visible around the box resonance frequency.
Could you make an overlay of the two curves? That would make it easier to spot differences. It would also be helpful to make a measurement with the woofer turned off to see how much background noise you capture.
Polyfill does not do too much at very low frequencies, though its effect should be visible around the box resonance frequency.
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I have used the calibration before on my Creative Omni soundcard (the mic preamp I am using is from an Mbox 1 as I have no other preamp available atm). No mic calibration.
Here is an adjusted graph, thanks for the note on resolution!
I assumed the polyfill would at least have some effect on the upper scale?
Here is an adjusted graph, thanks for the note on resolution!
I assumed the polyfill would at least have some effect on the upper scale?
Attachments
Sealed Tang Band W6-1139SIF Bracing
This is the box in question. The reason I used polyfill is because due to the length of the cabinet there might be a standing wave at the wavelength of 53cm. Was I being too uptight about this as I would probably never hear it?
My bracing was a bit extreme but I wanted to get to understand it for other compact projects. There is no equal panel unbraced. All areas are divided up in to non-equals areas.
This is the box in question. The reason I used polyfill is because due to the length of the cabinet there might be a standing wave at the wavelength of 53cm. Was I being too uptight about this as I would probably never hear it?
My bracing was a bit extreme but I wanted to get to understand it for other compact projects. There is no equal panel unbraced. All areas are divided up in to non-equals areas.
Attachments
Thanks. Certainly proves there's something wrong my end.
Did you use smoothing?
Did you use smoothing?
Yeah, something is obviously wierd. Here is a measurement I did on a pair of closed box W6-1139SIF a couple of years ago (near field):
The internal volume was 5 liters and filled with polyfill. I was using the MiniDSP Umik-1.
Hope that helps.
/Anton
Yes, that would be my preference but my back yard is rather small. Maybe I can't get away from the rooms modes inside?
Nope, no smoothing.
Measured outdoor, at about 2 cm distance.
Are you sure that REW is using the correct mic? Maybe it's using the internal in the laptop?
/Anton
yes, outside even in tight quarters at least removes the room nodes, but might still have reflections and such. It will allow you to at least verify that things are 'right' or not from a process perspective. If nothing changes, then something is wrong! The Hypothesis is that the low end output will go down drastically when removed from all the room gain / nodes. Try it at a meter and see!
Those numbers hurt my mind! Should I use the circled ones in future? Thanks for sharing!
Hi graham^2,All
What T/S Parameters did you use?
I find the Advertised Driver TS being somewhat misleading...
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