SPL meter acting weird

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MissileCrisis
Posts: 1128
Joined: Sat Dec 15, 2012 1:30 pm
Location: Walnut Creek, California

SPL meter acting weird

#1 Post by MissileCrisis »

I was just blasting some tunes and the SPL seems way off unless it is directed at the subwoofer. What is weird is it reads ~ 102 where I am sitting but I believe from the amount of physical bite it has that it must be more like 110. I am in a small room roughly 8 feet from the sub (in a bass "hotspot"). Could someone recommend a SPL meter that is at least decent in measuring bass (20-150 Hz
more important than full range, I just need one that will set my dayton mic).

Budget <100 if possible.

If this is the wrong place to ask please redirect me.

Further reinforced by the fact that I feel my neck close up when I play one of praktis's (forum member dj higgumz) songs gettin ziggy. At that moment when it feels insanely loud it measures 105-106, which just can't be right. Is the fact that the sub isn't pointing at it making it read low? I wouldn't think so since subs are omnidirectional down at 40 Hz. Any suggestions or explanations kindly accepted.
Built
2 x TLAH
1 Titan 39 (lab 12, 15 inch)
1 Tuba 60 (lab 12, 20 inch)
SLA Center
2 x Mini MLTP subwoofers
1 x 212 TH (custom)
2 x Mini-Karlsonators
Owned, but not built
2 x Jack 12 (2512, melded)

sine143
Posts: 3066
Joined: Sat Feb 06, 2010 3:27 pm
Location: Raleigh NC

Re: SPL meter acting weird

#2 Post by sine143 »

the question is, is your spl mic omnidirectional, cause it should be lol. I havnt had a chance to match my little apex up against anything thats known flat, but hopefully I'll be moving in that direction in the next couple months (NCSU has a big anechoic chamber, aka, I know they have good test mics that I can reference mine against when they get back in session).
Built:
2x Tuba 30s delta12lf loaded (gone)
4x Otop12 d2512 loaded
8x t48s (18, 18, 24, 24, 30, 30) 3015lf loaded
2x AT (1 mcm, 1 gto 804)
2x SLA Pro (dayton pa6, 6 goldwood piezo loaded)
1x bastard XF208

2x OT212 (delta pro 450a loaded, eminence psd)

MissileCrisis
Posts: 1128
Joined: Sat Dec 15, 2012 1:30 pm
Location: Walnut Creek, California

Re: SPL meter acting weird

#3 Post by MissileCrisis »

The SPL readings I got outside a few days ago still seem realistic considering I'm getting ~ 12 dB of corner gain (I'm probably peaking in the 120's with music with 40-60 hz content corner loaded)

those readings had the mic pointed at the mouth at ground level, it's the indoor ones that seem off.
Built
2 x TLAH
1 Titan 39 (lab 12, 15 inch)
1 Tuba 60 (lab 12, 20 inch)
SLA Center
2 x Mini MLTP subwoofers
1 x 212 TH (custom)
2 x Mini-Karlsonators
Owned, but not built
2 x Jack 12 (2512, melded)

sine143
Posts: 3066
Joined: Sat Feb 06, 2010 3:27 pm
Location: Raleigh NC

Re: SPL meter acting weird

#4 Post by sine143 »

again, you're gonna want a pair to fully realize the potential of the T60, or any horn design here on bfm. 30x20 is not a big mouth for a horn of that size, considering you want to hit 25 with authority.
Built:
2x Tuba 30s delta12lf loaded (gone)
4x Otop12 d2512 loaded
8x t48s (18, 18, 24, 24, 30, 30) 3015lf loaded
2x AT (1 mcm, 1 gto 804)
2x SLA Pro (dayton pa6, 6 goldwood piezo loaded)
1x bastard XF208

2x OT212 (delta pro 450a loaded, eminence psd)

MissileCrisis
Posts: 1128
Joined: Sat Dec 15, 2012 1:30 pm
Location: Walnut Creek, California

Re: SPL meter acting weird

#5 Post by MissileCrisis »

I know, but in order to know if I'm on the right track I need to know that my first one is operational, only then can I consider building/buying a 2nd.
Built
2 x TLAH
1 Titan 39 (lab 12, 15 inch)
1 Tuba 60 (lab 12, 20 inch)
SLA Center
2 x Mini MLTP subwoofers
1 x 212 TH (custom)
2 x Mini-Karlsonators
Owned, but not built
2 x Jack 12 (2512, melded)

sine143
Posts: 3066
Joined: Sat Feb 06, 2010 3:27 pm
Location: Raleigh NC

Re: SPL meter acting weird

#6 Post by sine143 »

oh I understand man... If I was in you're boat i'd be looking to measure someone elses gear with your measurment rig. have any friends with subs of any kind?

too bad your like 6 hours from Ian westwood. Looks like he's got quite the pile of t60s under his belt, and I'm sure he could probabably help you A/B yours.

where did you get yoru lab 12s for 146 btw?
Built:
2x Tuba 30s delta12lf loaded (gone)
4x Otop12 d2512 loaded
8x t48s (18, 18, 24, 24, 30, 30) 3015lf loaded
2x AT (1 mcm, 1 gto 804)
2x SLA Pro (dayton pa6, 6 goldwood piezo loaded)
1x bastard XF208

2x OT212 (delta pro 450a loaded, eminence psd)

MissileCrisis
Posts: 1128
Joined: Sat Dec 15, 2012 1:30 pm
Location: Walnut Creek, California

Re: SPL meter acting weird

#7 Post by MissileCrisis »

MUAHAHAHAHa. So I have amazon prime (free shipping). Amazon had a 5-10 % sale on a number of solid brands (random one day thing) which included eminence. Thus the 156.00 with free shipping became 140 something and I'm not sure if I was taxed but it ended up at 146 delivered. I'm about 7-8 hours from him although I'm planning a visit with him over PM if I don't get this settled in the next few weeks.
Built
2 x TLAH
1 Titan 39 (lab 12, 15 inch)
1 Tuba 60 (lab 12, 20 inch)
SLA Center
2 x Mini MLTP subwoofers
1 x 212 TH (custom)
2 x Mini-Karlsonators
Owned, but not built
2 x Jack 12 (2512, melded)

MissileCrisis
Posts: 1128
Joined: Sat Dec 15, 2012 1:30 pm
Location: Walnut Creek, California

Re: SPL meter acting weird

#8 Post by MissileCrisis »

I don't have friends in this area (meaning east san francisco bay area) that have subs. Heck I'm probably one of few that have any sort of subwoofer much less one with a frequency chart (at my age ~20).
Built
2 x TLAH
1 Titan 39 (lab 12, 15 inch)
1 Tuba 60 (lab 12, 20 inch)
SLA Center
2 x Mini MLTP subwoofers
1 x 212 TH (custom)
2 x Mini-Karlsonators
Owned, but not built
2 x Jack 12 (2512, melded)

sine143
Posts: 3066
Joined: Sat Feb 06, 2010 3:27 pm
Location: Raleigh NC

Re: SPL meter acting weird

#9 Post by sine143 »

aw cmon. san fran is big in the bass music scene. I'm sure you could make a connection with someone. I'm only 21 myself, and thank god for bill, as the t48s have been sustaining me and one significant other for over a year now (although we still havnt raised enough to buy a car due to some medical misfortunes).
Built:
2x Tuba 30s delta12lf loaded (gone)
4x Otop12 d2512 loaded
8x t48s (18, 18, 24, 24, 30, 30) 3015lf loaded
2x AT (1 mcm, 1 gto 804)
2x SLA Pro (dayton pa6, 6 goldwood piezo loaded)
1x bastard XF208

2x OT212 (delta pro 450a loaded, eminence psd)

MissileCrisis
Posts: 1128
Joined: Sat Dec 15, 2012 1:30 pm
Location: Walnut Creek, California

Re: SPL meter acting weird

#10 Post by MissileCrisis »

Being 20 rather than 21 makes it slightly more difficult :). But yeah it's mainly because this is where I grew up (I'm actually about an hour east of San Francisco) and no one is into music that has invested in proper subs. I could go to a club potentially but that would be strange taking meter readings in a crowd. Haha.
Built
2 x TLAH
1 Titan 39 (lab 12, 15 inch)
1 Tuba 60 (lab 12, 20 inch)
SLA Center
2 x Mini MLTP subwoofers
1 x 212 TH (custom)
2 x Mini-Karlsonators
Owned, but not built
2 x Jack 12 (2512, melded)

MissileCrisis
Posts: 1128
Joined: Sat Dec 15, 2012 1:30 pm
Location: Walnut Creek, California

Re: SPL meter acting weird

#11 Post by MissileCrisis »

Is this one good enough? It says it is type 2. What does that mean in terms of accuracy. It also has many more settings than my cheap spl meter. http://www.amazon.com/gp/aw/d/B000I4ZVH ... mdp_mobile
Built
2 x TLAH
1 Titan 39 (lab 12, 15 inch)
1 Tuba 60 (lab 12, 20 inch)
SLA Center
2 x Mini MLTP subwoofers
1 x 212 TH (custom)
2 x Mini-Karlsonators
Owned, but not built
2 x Jack 12 (2512, melded)

User avatar
Michael Ewald Hansen
Posts: 638
Joined: Tue Aug 16, 2011 10:43 am
Location: Denmark

Re: SPL meter acting weird

#12 Post by Michael Ewald Hansen »

MissileCrisis wrote:I was just blasting some tunes and the SPL seems way off unless it is directed at the subwoofer. What is weird is it reads ~ 102 where I am sitting but I believe from the amount of physical bite it has that it must be more like 110. I am in a small room roughly 8 feet from the sub (in a bass "hotspot"). Could someone recommend a SPL meter that is at least decent in measuring bass (20-150 Hz
more important than full range, I just need one that will set my dayton mic).

Budget <100 if possible.

If this is the wrong place to ask please redirect me.

Further reinforced by the fact that I feel my neck close up when I play one of praktis's (forum member dj higgumz) songs gettin ziggy. At that moment when it feels insanely loud it measures 105-106, which just can't be right. Is the fact that the sub isn't pointing at it making it read low? I wouldn't think so since subs are omnidirectional down at 40 Hz. Any suggestions or explanations kindly accepted.
Which weighting is your spl meter set for?

If its set for A weighting it will be down 20dB at 100hz..
Authorized Builder - Denmark
Check out the BFM Facebook page

User avatar
Charles Jenkinson
Posts: 1125
Joined: Sat Aug 06, 2011 3:25 pm
Location: Manchester, UK

Re: SPL meter acting weird

#13 Post by Charles Jenkinson »

MissileCrisis wrote:Is this one good enough? It says it is type 2. What does that mean in terms of accuracy. It also has many more settings than my cheap spl meter. http://www.amazon.com/gp/aw/d/B000I4ZVH ... mdp_mobile
That looks like the one I have. I think it's branded under a few different names. You may be paying over the odds for it there, try ebay.
2xJ12L (3012HO) switchable/melded
2xT30

Words&graphics - Audio&Acoustics - Hardware&DSP; 3 different paradigms.

MissileCrisis
Posts: 1128
Joined: Sat Dec 15, 2012 1:30 pm
Location: Walnut Creek, California

Re: SPL meter acting weird

#14 Post by MissileCrisis »

Its 70 us dollars over here. I'll look on ebay but my guess is it won't be much cheaper. My spl meter is c weighted. But it's not really accurate. That's why I'm replacing it.
Built
2 x TLAH
1 Titan 39 (lab 12, 15 inch)
1 Tuba 60 (lab 12, 20 inch)
SLA Center
2 x Mini MLTP subwoofers
1 x 212 TH (custom)
2 x Mini-Karlsonators
Owned, but not built
2 x Jack 12 (2512, melded)

Grant Bunter
Posts: 6915
Joined: Mon Nov 28, 2011 11:12 am
Location: Ilfracombe Queensland Australia
Contact:

Re: SPL meter acting weird

#15 Post by Grant Bunter »

MC
You can't measure subs with C weighting!
If you have the option, turn the weighting off totally...
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" KL3010LF , 2 x 28" 3012LF.
WH8: x 6 with melded array wired series/parallel.
Bunter's Audio and Lighting "like"s would be most appreciated...

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