As I mentioned, I'm new to the whole big speakers/big power amp thing, so I'm just being cautious with my system. I have a running library of my favorite clips from my movie collection that largely include big explosions and lots of LFE. I'm worried as I continue to watch them at higher and higher volumes that I'm going to push it too high and cause damage. So, I'm just trying to be aware of how much headroom I have. I'm a music lover, too, but haven't experimented with turning up my music as loud as my movies, yet.
At the same time, I'm trying to understand the relationship between JRiver internal volume, channel gain from room correction, preamp gain from the equalizer, etc. Basically, if I want my system to go louder, what's the best and safest way of doing it.
Good to know. I've been doing this wrong. I have to add 10-12db to my rears to get them at the same SPL as my fronts on the volume calibration test. Not to mention that I like having my center channel louder than all those for dialogue. So I'm worried I'm eating into my headroom quite a bit.
I don't use volume leveling. The peak levels in the audio analysis when watching a demo clip or THX intro or something turned up to about 75% volume reach only 40-45% at the highest. Am I really that far from saturating the signal? Would a lot of that be made up in the last 25% volume increase? Does this mean I have room to increase preamp gain for more volume if needed?
Thanks for all your replies, everyone!
I think you're blurring some categories here. As noted above, you can't actually add digital gain as almost all digital audio is mastered to peak at or near 0dB (you can see this looking at the peak levels from analyze audio). If the peak of a track is at or over 0dB that means that you can add zero gain without digital clipping, and may need to to actually reduce the volume from 100% to avoid clipping (if the peak is over 0dB).
JRiver tries to prevent clipping in several ways: for example if you add gain to a speaker in the Room Correction module specifically, JRiver actually just attenuates the other channels instead of boosting the one you're trying to boost. This only applies to the Room Correction module! Gain added in the equalizer or parametric EQ module can and will cause clipping (think of it as "expert mode" where the safety is off to some extent).
As an additional safeguard JRiver has a clip protection module that acts as a fast attack limiter that just turns down the volume rapidly when music would clip. That doesn't guarantee no sudden momentary clipping, but it prevents continuous clipping. This applies in general unless you explicitly turn it off, but if you've tried to add net gain in parametric EQ, you'll find clip protection keeps engaging and turning the volume down at loud parts which is not ideal, and you will on very sudden spikes in volume have the risk of real clipping (think gunshots).
To be clear, you should never configure DSP to add net gain in software, because 99% of all professionally mastered audio (stereo and film) peaks at or near 0dB. So you either need to convert desired gain into reductions other places (like with relative levels of channels), or reduce the total volume of all channels by enough to give you the headroom you need to add the gain (like with speaker correction).
All of that is about clipping in the digital domain. What happens once the signal is analog is entirely different and subject to an entirely different type of clipping (amplifiers also clip, but for different reasons). You mention a pre-amp; I'm not sure if you meant the "pre-amp" setting in JRiver's equalizer or a physical analog pre-amp separate from your computer. If you mean the JRiver equalizer, you can't add gain there either, the same rules apply as in the rest of the digital domain. If you mean a physical pre-amp, turning it up has nothing to do with the digital level; you have to do the math on your pre-amp, power amp, and speakers to determine if you can turn up the pre-amp without clipping. If you can describe your signal chain a little bit, we can help.
If your main concern is safety, first figure out how much power your speakers can handle (A), and how much power your amplifier can put out when fully driven by your soundcard/DAC (B). If (A) is less than (B), you should set your analog amp/pre-amp volume controls so 100% in JRiver is as loud as you'd ever want to listen to anything. If (B) is less than (A), you need to be careful, and do the math with your speaker's sensitivities and power handling to determine how loud you can safely drive them. Then set the analog volume controls appropriately. If you follow that method carefully, 100% volume will not pose an equipment safety hazard or an "ear" safety hazard. If you are only using digital volume controls, it's a little different (JRiver offers a max volume setting, and there are some tips to avoid system sounds), but the same kind of analysis applies.
Author
Topic: Analyze audio and clipping potential (Read 3389 times)