Is my old RS SPL meter dead?

[Chrisbee]

Hi

And the prize for this years most stupid post goes to: Moi?

I just can't get a signal out of my (old analogue) RS SPL meter from the output jack socket.

I am assuming the RS meter has a mono output socket. So if I stick a stereo jack in there I should still get a signal on a stereo cable. Right?

I have tried every combination of cables and jack adaptors from my collection in every possible way I can think of but every jack and adaptor I have is stereo.

I put my voltmeter across the other end of a stereo jack to phono cable and got nothing on my multimeter even @ 200mV (at any dial setting) from the RS meter.

A continuity check on the cable proved the jack ring was connected to the phono pin and the jack base to the phono shield.

Should I make haste to the nearest pro gear shop and buy a long mini jack to mini jack mono cable? Or just buy another RS meter?

Is life meant to be this complicated?

Any ideas for a conclusive check for output from the RS meter socket using stereo cables or adaptors greatly appreciated.

BTW: The 9 Volt battery in the RS meter is fine.

[brucek]

So if I stick a stereo jack in there I should still get a signal on a stereo cable. Right?

Don't know why you would assume this?

I've never seen a stereo RCA jack. Could you show us a picture. Below is a picture of three mono rca plugs.



brucek

[Chrisbee]

Thanks brucek

To me, a jack plug (or just jack) looks like the stereo example on the left.
(Formerly used for manual telephone exchanges and now mostly used for microphones and connecting pro-gear)

The pair on the right are phono (or RCA) plugs in the UK and commonly used for stereo audio interconnects.



Does this help?

[brucek]

OK, the pair of red and white male RCA connectors (on the right in your post) are the type that connect to the line output of the RS meter.
The pair you show are two mono RCA cables glued together for convenience.

See an example cable below:




In fact, you could connect the other end of that mono RCA connector cable (in my picture) into the left or right of the AUX or CD input of your receiver and the RS meter will act like a microphone. Use the dial on the RS meter and your receivers volume control as the adjusters for the volume and speak into the mic - does it work?

Then you can connect that mono RCA connector cable into one input of a stereo 1/8" phono to RCA adapter as shown below and connect that to the line in of your sound card.



brucek

[Chrisbee]

It grieves me to admit that for 15 years I have assumed (in error) that the output socket on my RS meter was a jack socket rather than an RCA (phono) socket.

I just discovered my error after dismantling the RS meter to discover a mini jack doesn't connect to any of the important bits of the socket.

So, finally, here is my first REW response curve for my 4 x 15" IB with the (40Hz) main speakers running as well. Crossover is at ~80Hz (24dB/octave). HT Shack correction figures applied.

BFD with just 4 filters set from manually recorded sinewaves. I can work on the BFD properly now I have REW working with my RS meter.

Never was I more pleased to see a wobbly line.

I have no idea what that massive dip is at ~150Hz.

Thanks to you all for your infinite patience.

[brucek]

So, finally, here is my first REW response curve

Good stuff. Now we have something to work with.....

You should turn off your mains and do a sub only sweep with all BFD filters off as a starting point (and save that mdat file). Set your target to 80dB rather than 75dB also.

brucek

[Chrisbee]

Okay. What is this going to tell us?

[Chrisbee]

BFD switched to 3. (no filters set)

Microphone input Soundblaster Live! External.

Speakers muted.

80dB target.

80dB on RS meter Calibration on pink noise.

REW is not able to control input level. So input level manually set to around 0.25(?) to achieve a close match between REW auto sub curve and my response curve.

I must have missed the lecture on mdat files.

[brucek]

Microphone input

Nope, has to be the line input to the soundcard.

Measure from 15Hz to 200hz....

brucek

[Chrisbee]

If only it were possible.

On Line-in I can only just get the first bar lit on the input level menu if I literally rap the microphone hard with my knuckles!

On the Microphone input I am totally swamped with signal level.

There seems to be no way to select/deselect between these two inputs on the SB Live!

I have input volume set at maximum.

I have discovered that plugging into the Microphone socket on the front seems to mute Line-in on the back of the box.

I'll keep digging in the SB L! Help files unless you have any good ideas to get Line-in working properly.

Thanks