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[nwboater]

We are now running a 5.1 system without a receiver. The soundcard outputs from our HTPC are going straight to the power amps. How should I properly set the levels? Our speakers and amps are not all the same and thus far I have just been setting by ear. Most modern receivers have a calibration method using a microphone. I do have REW on a separate PC and a calibrated mic if there is some way that would help.

Does JRiver have any plans for integrating this ability in MC?

Thanks,
Rod

[JimH]

There is a fair chance it could happen.

[nwboater]

There is a fair chance it could happen.

That's encouraging! Thanks Jim.

Rod

[mojave]

You can use the test tones in room correction and use REW on the other computer as an SPL Meter (if it is on a laptop or computer in the same room). Then adjust the level settings in Room Correction until the channels are the same level. Some amplifiers have a gain setting to allow you to match amplifiers, too. You should set these first before using the settings in Room Correction.

The amplifier for my mains expects a balanced signal with higher voltage. I use a Matchbox HD to increase the gain slightly from the soundcard to the amplifier. Since my mains are 86 dB efficient and my center is 90.5 dB efficient, I can get them balanced without making any changes in Room Correction to their relative levels.

[nwboater]

You can use the test tones in room correction and use REW on the other computer as an SPL Meter (if it is on a laptop or computer in the same room). Then adjust the level settings in Room Correction until the channels are the same level. Some amplifiers have a gain setting to allow you to match amplifiers, too. You should set these first before using the settings in Room Correction.

The amplifier for my mains expects a balanced signal with higher voltage. I use a Matchbox HD to increase the gain slightly from the soundcard to the amplifier. Since my mains are 86 dB efficient and my center is 90.5 dB efficient, I can get them balanced without making any changes in Room Correction to their relative levels.

Thanks for the tips! I have a Radio Shack SPL meter also, but using REW with a laptop next to our HTPC and the mic at the listening position is probably the easiest. Also each of our amps has gain controls.

So if I balance each amps gain pot for equal volume using the test tones then MC using Direct Show, Dolby, JRSS etc should put out the proper volumes on LR, C, Surrounds and Sub outputs? Sounds almost easy!

It will be even better when MC makes the internal gain adjusts from a mic input automatic, but one should probably still do at least a crude balancing first with their amps gain adjusts.

I have to get one of our laptops back from the boat to try this out, so it may be a day or two. It should be interesting to see if the levels end up anywhere near where I have them now from just guessing.

Rod

[mojave]

So if I balance each amps gain pot for equal volume using the test tones then MC using Direct Show, Dolby, JRSS etc should put out the proper volumes on LR, C, Surrounds and Sub outputs? Sounds almost easy!

Yes, it is that easy! I would set the the gain pots to max and then decrease the gain for the channels that are too loud. Alternatively, you can set all the gains to max, and use Room Correction to attenuate the levels. Either way has advantages/disadvantages and I'm not sure which is best in your situation. I still have to dig out my calibrated microphone and setup using REW. For now, I just set the levels with a Radio Shack SPL meter. If you have your meter there, it shouldn't take too long.

[JimH]

For now, I just set the levels with a Radio Shack SPL meter. If you have your meter there, it shouldn't take too long.

Is this the meter?
http://www.radioshack.com/product/index.jsp?productId=2103667#

[nwboater]

Yes, it is that easy! I would set the the gain pots to max and then decrease the gain for the channels that are too loud. Alternatively, you can set all the gains to max, and use Room Correction to attenuate the levels. Either way has advantages/disadvantages and I'm not sure which is best in your situation. I still have to dig out my calibrated microphone and setup using REW. For now, I just set the levels with a Radio Shack SPL meter. If you have your meter there, it shouldn't take too long.

I'll do that later with my meter. I'll be at the PC and ask my wife to be at the LP taking readings.

Think I'll adjust the amp gains as that way nothing gets changed in MC. At least Room Correction will always show gains at 0. Seems like that should be fine here.

BTW Jim asked which meter you used. We have the older analog style the 33-2050. Think I read somewhere that it's supposed to be a little more accurate than the digital ones. But that could just be a bad rumor too!

Rod

[mojave]

Is this the meter?
http://www.radioshack.com/product/index.jsp?productId=2103667#

Yes