AVS Forum banner
Status
Not open for further replies.
1 - 6 of 6 Posts

·
Banned
Joined
·
6,051 Posts
Discussion Starter · #1 ·
What do you exactly do.


I took my soundmeter and set it to 60 as their is no level below that on the machine and placed to next to the projector. It was giving me a reading of somewhere between 60 -70. Is this correct? And if so, is their something wrong with my machine. I currently have the new Dwin DLP.


Additionally, how do people measure in the 30s when the analog soundmeter cannot register below 50. Again, am i looking at this wrong?
 

·
Registered
Joined
·
1,735 Posts
Hi Humey,

I have been thinking of purchasing this unit as it also has a "flat" setting that is supposed to measure the entire audible spectrum without need for adjustments in the lower 2 octaves. The link is here You would want to purchase the "L" version to measure low SPL levels. I believe both partsexpress and markertek sell Goldline products.


Don O


PS Hi Tom, nice review on the scalers.


------------------

STOP HDCP on DVI

Don O
 

·
Registered
Joined
·
1,270 Posts
RadioShack has two similar SPL meters, but these only go down to 60dB or so. One analog and the other digital. These are fine for setting up the relative speaker levels using the tone generator in your receiver, but may not be sensitive enough for taking absolute measurements of the projector.


Using one of the RadioShack meters, my computer at work puts out over 70dB right next to the case, but from my seated position, it drops off the measurable scale. This computer is way too loud for a home theater set up, so a meter with more dynamic range is really needed to make good measurements from the seated position.


One side note, the RadioShack meters due provide a calibrated output that could be feed into your sound card and recorded as a wav file. Using a tool like Cooledit you can take a look at the wave file and make fairly accurate measurements of the SPL once you calibrate the recorded data. I would think that a measurement within 6dB of the actual value should be possible with type of setup. But 6dB is quite a lot.


There may be some nonlinearity in the response of the microphone or the soundcard ADC, but this method would be a lot cheaper than spending $300 bucks on a professional level SPL meter. That is if you have the software needed to perform the WAV file calibration and measurement.


In reality, this is how older equipment is always set up. Use a known calibrated source and take a measurement. Then calibrate the instrument. Now you're ready to take real measurements.
 

·
Banned
Joined
·
6,051 Posts
Discussion Starter · #6 ·
I appreciate your answers, however, you didnt answer the most important question. When I put the soundmeter up to the Dwin DLP, i get reading of over 60. Should this projector be so loud.
 
1 - 6 of 6 Posts
Status
Not open for further replies.
Top