Finally found a SPL meter, is it okay?

[Lightning Steve]

I've been looking all over for a SPL meter and no one ever had any, or even knew what I was talking about. Finally our Radio Shack or what ever they are now had some, so this is what I got as it was all they had.
http://scosche.com/products/productID/582
(The one on the page says 60-135, but mine says 30-135)
I don't know if this is good enough but it seemed to do the job. The Yamaha doesn't have auto speaker set up so I was kind of surprised at some of my readings. Nothing major, but my seat is slightly right of center and I always perceived the right main speaker to be louder than it actually was. I also had my rear surrounds quite abit lower than they should have been. One of the other things was the reading when the sub played the test tone. Even though there wasn't much noticeable sound the meter would read about 10db higher than the 75db I set everything to (at 0 volume level). Should I set the sub up so it also is at 75db? It all sounded real good when I was watching The Dark Knight, had the meter running when I was watching and hit a high of 100db with the receiver volume at -19.

 

[sptrout]

I have never seen any one mention that specific SPL meter before so I cannot comment on it. Most people use either of these two Radio Shack SPL Meters: http://www.radioshack.com/family/index.jsp?categoryId=2032222

Most seem to prefer the analog version, some the digital model. I have owned/used both, but have the digital model now.

Your level setting look fine to me. Setting the subwoofer level can be very difficult because just moving the meter a very short distance (in inches) can really change the reading (a factor of low frequencies not the meter). Large swings in subwoofer measurements are very typical. I have found that I prefer that the subwoofer level be set a little higher than the other channels, but it really becomes a trail & error method at the end to find the subwoofer level that you like.

Now, I have an Onkyo 805, which does have auto-setup & EQ so life is good

 

[Alex2507]

I don't know if this is good enough but it seemed to do the job. The Yamaha doesn't have auto speaker set up so I was kind of surprised at some of my readings. Nothing major, but my seat is slightly right of center and I always perceived the right main speaker to be louder than it actually was. I also had my rear surrounds quite abit lower than they should have been. One of the other things was the reading when the sub played the test tone. Even though there wasn't much noticeable sound the meter would read about 10db higher than the 75db I set everything to (at 0 volume level). Should I set the sub up so it also is at 75db? It all sounded real good when I was watching The Dark Knight, had the meter running when I was watching and hit a high of 100db with the receiver volume at -19.

I think the meter will serve to set the channel gains just fine. Just get it as close to where you head would be as possible and point it up so that the different channels affect it in a similar way. A tripod is ideal or propped up somehow. In order to bring the sub back in line with everything else you could turn the sub volume down a little on the sub itself. The general consensus is that the sub volume should start out turned up about 1/2 way.

The 75dB number is what each individual channel puts out when isolated with a test tone. During a movie that number will go all over the place depending on what is being played. 100dB sounds pretty loud to me but understandable as a peak with your sub running 10dB hot during a bass heavy scene.

Is your rec'r generating the test tones? I had calibrated a friends system using his receiver's test tones. Recently I calibrated it using the test tones on an Avia II disc and found a discrepancy. I opted to put my faith in the tones on the disc rather than the ones generated by the rec'r.

At (at 0 volume level), what are your channel gains set at to produce the 75dB? I think you have to reign that sub in. Having excessive bass tends to wash out everything else, making dialog difficult to understand. Lots of guys run their subs 3dB hot because humans don't hear LF very well. Personally I run everything even. If I find dialog in a movie difficult to hear at my relatively low listening levels I turn up the center channel by 3dB.

The audio in Dark Night is being discussed here:

http://forums.audioholics.com/forums/showthread.php?t=50466

I bet you're lovin' it.

 

[j_garcia]

I believe you can still order one from SVS> http://www.svsound.com/questions-faqs.cfm#meter

 

[Lightning Steve]

Is your rec'r generating the test tones? I had calibrated a friends system using his receiver's test tones. Recently I calibrated it using the test tones on an Avia II disc and found a discrepancy. I opted to put my faith in the tones on the disc rather than the ones generated by the rec'r.

At (at 0 volume level), what are your channel gains set at to produce the 75dB? I think you have to reign that sub in. Having excessive bass tends to wash out everything else, making dialog difficult to understand. Lots of guys run their subs 3dB hot because humans don't hear LF very well. Personally I run everything even. If I find dialog in a movie difficult to hear at my relatively low listening levels I turn up the center channel by 3dB.

I bet you're lovin' it.

Yes using the receivers test tones, I'll have to see if I can find something like the Avia II disk. Have been wanting to get something like that for a while. Had the meter right infront of my face, eyes gettin old eh! and pointed straight up.
The channel gains are all pretty close to "0", LR-0, RR-1, FL-0, FR-1, C-0.
Center channel comes through very sharp and clear. The sub (subs accually as I have both hooked up on either side of the room) might be a bit loud. They are set volume wise a bit over half way. I've just got the two hooked up to try it and see how it sounds, which so far seems okay. The 100db was durring TDK and I assume from the LFE, receiver volume was at -19, which is a bit more than I would normally have it at, usually -21. I'll do some more experimenting with the sub volume, man now I'll have to watch more movies, does the work never end,LOL.

 

[Alex2507]

Have you seen this?:

http://www.audioholics.com/tweaks/get-good-bass/subwoofer-connection-guide

It was written just for you.

I read somewhere that holding the SPL meter too close allows your body isn't the way to go. I think having it at arms length was the ticket to prevent the readings from being affected by reflections from you. It might be splitting hairs and I'm hazy on the details. I picked up a little tripod at a dollar store for a dollar. For me that was the real deal.

There's enough well written info on the main page in tips and tricks. Going through that above link will really help with the dual subs. The big thing that I see right now is matching one to the other to begin with.

j_garcia's post linking the other meter could help you be the coolest A/V nut in London. Two SPL meters.

 

[Lightning Steve]

I believe you can still order one from SVS> http://www.svsound.com/questions-faqs.cfm#meter

Just tried to order and they don't do Canada???
They have a listing for Ontario but not the country.
Every other country in the world but us???
There is a Canadian partner but they only show the Avia (not Avia II, what's the differance?) plus it about $40 differance!

 

[Alex2507]

So maybe you're not gonna get to be the coolest guy in London.

I'm not sure how much snooping you do around here but this thread:

http://forums.audioholics.com/forums/showthread.php?t=50359

is full of info regarding SPL meters. C Weighting and Slow Response settings are of some importance and it's a good read. I'm know you've made some huge improvements in the last week or so. I'm just offering the link because I think the info is cool and it features some of AH's best and brightest.

I think Davemcc, PENG and Sheep might know the ins and outs of Canadians getting their hands on stuff up there. You can't have it all you know, great weather and easy access to electronics.

 

[Lightning Steve]

So maybe you're not gonna get to be the coolest guy in London.

I'm not sure how much snooping you do around here but this thread:

http://forums.audioholics.com/forums/showthread.php?t=50359

is full of info regarding SPL meters. C Weighting and Slow Response settings are of some importance and it's a good read. I'm know you've made some huge improvements in the last week or so. I'm just offering the link because I think the info is cool and it features some of AH's best and brightest.

I think Davemcc, PENG and Sheep might know the ins and outs of Canadians getting their hands on stuff up there. You can't have it all you know, great weather and easy access to electronics.

I had read that post (that day), that's what prompted me to go looking again for the SPL, and found the one I got at Radio Shack. The main page info on subs is good reading, I've read over it acouple of times now, several more times and I might even understand half,LOL.
You can never have good info pointed out to much.
Thanks Alex

Great weather?? RI must be further south than I thought,LOL. Did you get hit with that ice storm at all?

 

[ThA tRiXtA]

Hi Lightning Steve,

Here is a store from Canada that sells SVS products, which includes stocking the SPL meters and calibration material.

Good luck to you.

Edit: actually, the store is in Markham, near Toronto... up for a road trip?

 

[Alex2507]

I've read over it acouple of times now, several more times and I might even understand

Great weather?

I'm the same way. I need to read stuff again and again to really get it. Even then I forget the details. That's why I like to post links to articles. With you I just wasn't sure about how much of the site you had explored. We seem to be on relatively equal ground on that score then.

The weather thing was a joke about Canadians having great weather and being able to get all the deals. Bad joke. I'll do better next time.

 

[Cpt.America]

I think measuring and setting the output of your sub(s) is a bit pointless... at least it is in my system. I can put in a DVD-A of one particular band, and the low-end output of that disk might by REALLY low, causing me to turn it up to lets say 2/3rds the way up to get any real thump out of it. Then I can toss in Transformers lets say on blu-ray, and will have to turn the sub DOWN to less than 1/3rd because there is SO much bass on the disk. It really varries that much from source to source.

 

[Alex2507]

I think measuring and setting the output of your sub(s) is a bit pointless... at least it is in my system.

I could not disagree more ... for any system. I just didn't want the above statement to be the last word on calibration in this thread. Frankly I'm surprised it has gone unchallenged this long. I understood that controlling the low frequency out put was of the utmost importance.

I'm not trying to be argumentative. Obviously you can and should do whatever makes you happy. I'm just pointing out that proper calibration in my personal view is the path to better sound quality.

Having said that I'm glad to hear that you use and enjoy your system. That's the real objective for all of us.

 

[Nemo128]

Thread jack, sorry.

Should I use the SPL meter if I have auto-setup on my NR906?

 

[Midcow2]

+1

I could not disagree more ... for any system. I just didn't want the above statement to be the last word on calibration in this thread. Frankly I'm surprised it has gone unchallenged this long. I understood that controlling the low frequency out put was of the utmost importance.

I'm not trying to be argumentative. Obviously you can and should do whatever makes you happy. I'm just pointing out that proper calibration in my personal view is the path to better sound quality.

Having said that I'm glad to hear that you use and enjoy your system. That's the real objective for all of us.

+1 I agree with you Alex. I will admit iIwas skeptical at first that it could beat the Audessy automatic settings with my own tweaking added, but then I calibrated with SPL meter and it sounds so much better. And yes I did set the sub about 10 dB higher.

Nemo0128 = YES

Take care,

MidCow2

 

[Nemo128]

I'll pick one up before the weekend, my local RadioShmuck has the analogs in stock.

 

[ErinH]

IMO, c-weighting isn’t very useful. Factor in the loudness curve (representative of how we hear) and c-weighting is still a bit off. I’ve found when setting things up, a-weighting is the best way to tune.

Also, for the radio shack SPL meters, you might be interested to know that there are a lot of calibration plots/info out there, discussing how ‘off’ the readings are on those meters.
http://www.avsforum.com/avs-vb/showthread.php?t=505236



*** break****


Now… what about a true RTA setup, rather than the SPL mic? Then you can get readings like this instead of using a meter and copying down all your settings, then having excel plot things for you.

If you have a laptop, or a computer in your audio room, pay about $150 to set your current laptop for RTA purposes, rather than buying the SPL meters. RTA software is out there... good stuff for free if you know where to look. The best part is that you can even get down to 1/24dB resolution on the lappy version, whereas most SPL meters I’ve seen only do 1/3rd Octave.
This is the hardware I use:

M-Audio Mobile Pre
http://www.zzounds.com/item--MDOMOBILEPRE

Behringer ecm8000 Mic:
http://www.zzounds.com/item--BEHECM8000

Connected via a standard xlr cable:
http://www.zzounds.com/item--SHUC25J


I bought the mobilepre on e-bay for $80 shipped. The mic was $50 and the cable was $10. In total, I paid about $150 shipped.
I personally like the mobile pre as the ‘soundcard’. It has many connections, and to me, it just seemed ‘safer’ than using the laptop soundcard. Plus, it provides phantom power for the mic.


I have TrueRTA, SmaartLive, and ARTA. ARTA is completely free. TrueRTA is free for the 1 octave resolution, but costs a bit for each step (1/3, 1/6, 1/12, 1/24dB). I think the 1/3dB is about $30-40, iirc. I ‘obtained’ smaartlive, and honestly just prefer using this program is it’s easy to use. All plug and play and it has a-weighting. TrueRTA is c-weighted out of the box, but with a little studying of the above linked sites, you can make it a-weighted yourself.

If you want to do time response measurements with this to dial in time arrival, you can. But, you’ll have to have to make a feedback cable. Luckily, someone on another forum made me one of these about a year ago. If nothing else, it’s good for just generating pink noise/sweeps, etc, and playing it through my system via the AUX input.

I’ve compared my setup against a $1000 Audiocontrol piece that’s used for acoustical purposes in construction, audio setups, etc. and I had the same results… and mine also does higher resolution.

All in all, having the laptop RTA is easily THE BEST money I’ve ever spent in audio. Without a doubt. It’s absolutely wonderful to play a track, and when you hear something that’s not quite right, look over to the RTA and see what frequencies it is. I don’t have golden ears, so it’s a huge help to have this.

Anyway, just throwing it out there. It’s great, VERY easy to use, and above all, is a great learning tool.

 

[Alex2507]

Thread jack, sorry.

Should I use the SPL meter if I have auto-setup on my NR906?

I don't know anything about the NR906. There's an article around here about what the shortcomings are of most auto set ups. IIRC the RS SPL meter is a much better tool for level matching than any of the auto setups around at the time the article was written and it's only $50. For me it was a 'good enough' approach seeing as I don't have a lap top etc.

 

[Nemo128]

IMO, c-weighting isn’t very useful. Factor in the loudness curve (representative of how we hear) and c-weighting is still a bit off. I’ve found when setting things up, a-weighting is the best way to tune.

Also, for the radio shack SPL meters, you might be interested to know that there are a lot of calibration plots/info out there, discussing how ‘off’ the readings are on those meters.
http://www.avsforum.com/avs-vb/showthread.php?t=505236



*** break****


Now… what about a true RTA setup, rather than the SPL mic? Then you can get readings like this instead of using a meter and copying down all your settings, then having excel plot things for you.

If you have a laptop, or a computer in your audio room, pay about $150 to set your current laptop for RTA purposes, rather than buying the SPL meters. RTA software is out there... good stuff for free if you know where to look. The best part is that you can even get down to 1/24dB resolution on the lappy version, whereas most SPL meters I’ve seen only do 1/3rd Octave.
This is the hardware I use:

M-Audio Mobile Pre
http://www.zzounds.com/item--MDOMOBILEPRE

Behringer ecm8000 Mic:
http://www.zzounds.com/item--BEHECM8000

Connected via a standard xlr cable:
http://www.zzounds.com/item--SHUC25J


I bought the mobilepre on e-bay for $80 shipped. The mic was $50 and the cable was $10. In total, I paid about $150 shipped.
I personally like the mobile pre as the ‘soundcard’. It has many connections, and to me, it just seemed ‘safer’ than using the laptop soundcard. Plus, it provides phantom power for the mic.


I have TrueRTA, SmaartLive, and ARTA. ARTA is completely free. TrueRTA is free for the 1 octave resolution, but costs a bit for each step (1/3, 1/6, 1/12, 1/24dB). I think the 1/3dB is about $30-40, iirc. I ‘obtained’ smaartlive, and honestly just prefer using this program is it’s easy to use. All plug and play and it has a-weighting. TrueRTA is c-weighted out of the box, but with a little studying of the above linked sites, you can make it a-weighted yourself.

If you want to do time response measurements with this to dial in time arrival, you can. But, you’ll have to have to make a feedback cable. Luckily, someone on another forum made me one of these about a year ago. If nothing else, it’s good for just generating pink noise/sweeps, etc, and playing it through my system via the AUX input.

I’ve compared my setup against a $1000 Audiocontrol piece that’s used for acoustical purposes in construction, audio setups, etc. and I had the same results… and mine also does higher resolution.

All in all, having the laptop RTA is easily THE BEST money I’ve ever spent in audio. Without a doubt. It’s absolutely wonderful to play a track, and when you hear something that’s not quite right, look over to the RTA and see what frequencies it is. I don’t have golden ears, so it’s a huge help to have this.

Anyway, just throwing it out there. It’s great, VERY easy to use, and above all, is a great learning tool.

Seems... excessive. I need to post a CAD model of my listening environment. You guys will probably think I am nuts for having what I have in it.

 

[ErinH]

Seems... excessive. I need to post a CAD model of my listening environment. You guys will probably think I am nuts for having what I have in it.

Excessive? Hardly.
No offense, really, but for an audioholics forum, I'm very surprised that more people don't do these types of measurements, or at the least haven't heard of them and show more interest than simply passing it off. You took the time to do a CAD model and you're saying a Real Time Analysis capture is excessive?....

How is it excessive to see how your speakers FR really is? Your environment shapes how your achieve your sound. Why would you not want to know how the geometry of your room, placement of your speakers, the speakers' build, the driver's network configurations, etc impact what you hear? Quite frankly, I think it's a bit crazy to spend thousands on audio gear and thousands on room treatments and not have some sort of calibration device. Truthfully.

On top of that, this is a thread about SPL measurements. What it would take 30 minutes to do with an SPL meter, you can literally do in 30 seconds. Push 'play', hit 'record' on the computer and you're done. That's it. I've had the SPL meter and the extra $100 I put into making an RTA is well worth it for more reasons than just level matching.



My $.02