SPL Help Please

[duaplex]

Hi Guys







So decided to buy myself a sound meter from Maplins and have
a few questions please. The link for the meter is below.

http://www.maplin.co.uk/mini-sound-level-meter-226470?c=froogle&u=226470&t=module



I have been told increase the volume of all speakers to 75db
and increase the sub volume to 82db.
Here is where the problem starts and my dilemma



1.
The room has a natural reading of around 40 - 50db
(fluctuates). Should I account for this and add it on to the final reading? So
increase the volume until my meter reads 115db or should I not worry about it
and still hit 75db.



2.
I have settings on the meter called Max and Min.
Should I use these or just continue without them on the standard setting?



3.
Start volume on the AV, or does this not matter
before going into settings?



4.
Should I buy a better meter and any suggestions?


Thanks as always guys

 

[duaplex]

Sorry about opening post, dont know what occured there?? :?

 

[fayeanddavid]

Duaplex

Just had a look at this on the link.

So, the unit is C weighted which is what you need, and a slow reponse would have been good but no worries as it will do

What you are measuring is the output SPL of each speaker, not background noise, so;

Use the amp for your valume control of each of yor speakers, set your sun about mid way on it's gain(volume) button, set all speakers to Smal (regardsless)

What you are looking for is a consistend 75dB on the SPL at your litening poition with the sound meater pointed upwards. st ear height, and not towards the speakers

Then adjust each and all of your speakers to the same value (viz 75dB) including the sub.

Then play a movie, have alisten, trim as you need (sides may be too loud, centre needs a biit more, sub too loud etc)

7dB is used as a Ref Level for listening, it is not cast in stone though, once set via SPL liten at normal levels, don't adjust Front Left and Right, but adjust the others as need be

In my set up my Center is +1dB, sides -1dB and my sub is -3dB with respect to the L&R speaker levels

It's all a matter of set up, ears and what you personally like.

good luck

 

[Oldboy]

Hi,

Select slow response on the meter, C weighting and don't use the min or max settings on the meter just keep the rest as standard. As for the volume setting i always set my amp at 75db before calibration as i find it's more accurate but some people say it's not necessary, i find it gives far better results however, but you don't need to take into account any ambient level of your room before you start...you are just looking for 75db from each speaker from the test tone under normal conditions.

Leave the sub at the levels from your auto/manual calibration results and use the volume level on the sub to adjust the sub levels, you will find it tricky to get an exact reading due to the nature of bass sound so just aim for an average of 75db and then play some bassy music afterwards to adjust further as you may well want to tone it down or turn it up after calibration.

Providing the meter has C weighting and (preferably) slow response settings there is no need to buy another meter as these are the two setting that are most important when using a spl to set your speakers. One word of caution regarding the centre speaker...after calibration you may find it drowned by the rest of your speakers so turn it up or down to taste and don't get too hung up about it not being accurate, typically a centre speaker needs to be turned up to stop the dialogue getting lost to the rest of your system.

For example after my calibration i had to turn the centre up a good 6-7 notches to get it right but it sounds lovely now, after calibration all dialogue was lost to the rest of my speakers and very hard to hear.

Hope that helps

 

[Sliced Bread]

I'd recommend doing the sub by ear. SPL meters are terrible for measuring bass, especially when subs need minute adjustment to sound their best.

 

[DJEPSON]

I am having problems with my set up and using my sound meter

1) Do I set the volume to my normal listening level on the amp, then run the tone test and adjust to 75 dbl within the test tone menu on the amp or do i set the volume on the amp to 75 dbl then run the test ?

2) I have a PV1 sub and per the instructions set the volume at the 12 o'clock position when I run the tone test I am only getting about 50 dbl reading, but if i adjust the volume on the sub to get 75 dbl, it is ridiculously loud and overpowering and during movies is very boomy and you can feel the floor vibrate at times and also annoys the neighbours !

Thanks in advance

 

[michael hoy]

Set the amp at 0db (reference level), use the test tone built in to the amp, this is a constant sound level no matter what the volume level is set to on the amp but I start at this level.

Set the 5,6 or 7 speakers you have to 75db (C weighting and slow response)

Leave the sub set as per manufacturers instructions and after any auto calibration adjust the sound level on the amp to slowly reach the 75db, it is possible but a little tricky with the sub.

 

[duaplex]

Ok, fantastic stuff! I have just set my AV to the recommended settings and its close, very close! So guys how important is this slow response on the meter?

 

[DJEPSON]

I am still slightly confused, I use the volume control on the amp and adjust the volume to 0 db, then I run the tone test and within the tone test menu I then adjust the volume of each speaker within the amp to get 75 db and save those setting ? But when I adjust the volume to my normal listening levels, usually around 25 db what happens ?

 

[Oldboy]

Ok, fantastic stuff! I have just set my AV to the recommended settings and its close, very close! So guys how important is this slow response on the meter?

Slow response is a setting that get's closer to the range of sound heard by the human ear, it's by no means a deal breaker with the meter but is definately the best setting to use if your meter has the setting on it. You should still get an accurate reading without it so don't worry about it too much.

 

[Oldboy]

I am still slightly confused, I use the volume control on the amp and adjust the volume to 0 db, then I run the tone test and within the tone test menu I then adjust the volume of each speaker within the amp to get 75 db and save those setting ? But when I adjust the volume to my normal listening levels, usually around 25 db what happens ?

Exactly. Depending on how your display shows the sound level you set the amp to either reference level (85 on my Onkyo), 75db or 0 then run the test tones and adjust until you get a 75db reading on the spl, after calibration you may find that the sound levels are slightly higher or lower than before at normal listening volumes depending on if you had alot of adjustment up or down from the original settings.

Btw most amps have an option to change how the sound levels are shown (normally named absolute or relative) and relative will show the sound in db rather than a 1-100 form which may be useful. It sounds like your amp is already displaying in relative so set it to 0db before you begin, hope that clears up any confusion.

 

[DJEPSON]

I have another question, the volume on my amp when it turns on comes on at 25 db and this is our usual listening level give or take, is this correct ? or should this be set to 75 db prior to running the level set up ?

 

[Oldboy]

I have another question, the volume on my amp when it turns on comes on at 25 db and this is our usual listening level give or take, is this correct ? or should this be set to 75 db prior to running the level set up ?

It shouldn't really matter where you set it prior to calibration as what you are adjusting when calibrating is the 75db or reference level of the amp but i found it helped me get more accurate results if i turned the amp up before calibration. If your normal listening volume is 25db, which sounds about right as mine is about 20db give or take then just give it a some extra volume prior to calibration.

What i done was switch the volume setting from relative to absolute and set the volume at 75 prior to calibration and it gave me excellent results but you don't have to do this just turn the amp up a little prior to calibration, preferably to the 0 mark and you should be fine from there.