SUB measurements SIM3/SMAART7   Leave a comment

So during the measurements done in the post before this 1 i also was asked to do measurements on a few SUBS . The problem you run in to has to do with the analyzers preference in synchronizing (i.e. finding the delay to synchronize the reference signal to the mic signal) .

All FFT analyzers like to synchronize in the MID-high area . Synchronizing on SUBS is a bit more difficult for a SMAART/SIM/whatever system you like best . I tried it with smaart but i didn’t succeed (maybe some one at rational can tell me how to do this with SMAART. I’m sure there is a way that i just don’t know it yet).

SIM3 can do this it only takes a bit more time . This has to do with changing settings in the delay finder . So first you have to set the Analysis Time settings to 560ms .Settings sim sub measurement  Then set the AVS (avarager settings) to 16 .SIM sub measurement settings 

The reason why it’s a bit difficult to measure subs has to do with the frequency range with regards to wave-length / period . It’s a “bit” time stretched . (so 50Hz has a period of 20 ms 100Hz 10ms which are quit long in analyzer world) . The stretching gets worse when High-pass and Low-pass filters are applied to subs (and after that you get to deal with room acoustics which will bluer your measurement even more) so i use this kind of measurements only to verify polarity on subs and to see if there are no problems going from 1 sub to the next .

So you have to take the following data in the screenshots not to serious but do not take it for granted either (nice can’t trust the data but can’t throw it away either).

I recently purchased a set of 8 used Meyer Sound USW1p subs . I did take SIM3 with me so here are the measurements i did to verify them .

The reference USW1p .

001 USW1 reference

The 2nd USW1p compared to the first .

002 USW1p 2

The 1st to 4rt USW1p’s compared .

003 USW1p 1 to 4

The 5ft to 8th USW1p’s compared .

004 USW1p 5 to 8

So most of the time you do not have to deal with this . Usually you measure any kind of top (what ever suits you best) and than the subs get aligned @ the x-over . This means you synchronize at a full-range signal and thus a different time compared to were the subs are .

Somebody had a problem with me linking to a screenshot online so this is gone now .

How ever it gave me an idea for a future post (en kappen met dat gedoe aub is te warm voor dit soort geleuter:-) .

Let’s move on .

So the following data and the comparing screenshots between SIM3 and SMAART7 where done by synchronizing SIM3 on the subs and than using the time found by SIM3 within SMAART7 .

First rabbit to bite the dust is a 15” horn loaded sub from VA .

005 SUB horn loaded 15 inch

Second rabbit is 2 15” horn loaded subs from VA (SIM3). So 1 sub vs 2 subs with x-over filters applied to them . 

005 SUB horn loaded 15 inch x 2 vs 1

Second rabbit is 2 15” horn loaded subs from VA (SMAART7). So 1 sub vs 2 subs with x-over filters applied to them .

006 SUB VA Filtered single vs double SMAART

So 1 sub vs 2 subs (with x-over filters applied to them) vs the same sub with no x-over filters applied to them (the level on the highest 1 in the magnitude screen might be 2 subs without x-overs applied or me f*cking up again and changing the gain to get a better measurement do not know sorry).

005 SUB hornloaded 15 1 1 2 and same sub nof

So 2 subs (with x-over filters applied to them) vs the same sub with no x-over filters applied to them .

006 SUB 15 hornloaded 2 x filtered vs nof SMAART

Third rabbit is a 18” horn loaded subs from needing some more work (SIM3) . With x-over filters applied to it .

18 sub filtered

Third rabbit is a 18” horn loaded subs from needing some more work (SMAART7) . With x-over filters applied to it .

007 SUB UT 18 filtered needs some more work SMAART

Third rabbit is a 18” horn loaded subs from needing some more work (SIM3) . With x-over filters applied to it vs no filters.

18 sub filtered vs nof

Third rabbit is a 18” horn loaded subs from needing some more work (SMAART7) . With x-over filters applied to it vs no filters .

SUB UT 18 hornloaded filtered vs nof needs some more work SMAART

So now the last screenshots of smaart’s live impulse responses on these subs . Really nice about these is you can see the difference in time as x-over filters are applied to the sub .

15”horn loaded sub no x-over filters .

Sub no filters ir

15”horn loaded sub with x-over filters .

Sub 15 filtered ir

18”horn loaded sub no x-over filters .

SUB 18 no filters IR

18”horn loaded sub with x-over filters .

SUB 18 filtered ir

The dip in the frequency response @63Hz in the screenshots after the USW1p SIM3 screenshots are always there if i measure in that particular room so that’s acoustics for you (can’t beat that just accept it as a fact of live if you do not have the money for a anoic chamber which i don’t).

SO AGAIN I LIKE TO WORK WITH BOTH PROGRAMS AND I’M NOT BIASED TO EITHER ONE !!!!! 

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