[lmf22]

I'm currently using iTunes with Foobar2000 pass-thru but my Entech 203.2's output is too loud when connected to LDM+ (stock gain) and there isn't much room to adjust the volume on it. It's barely past 9 o'clock position. Anything lower and the right channel cuts off. The hard -6db limiter plug-in works good, but still doesn't give much more room for volume adjustment. Does Foobar2000 have a hard -12db limiter?

 

[breez]

Can't you use the volume control in Foobar?

 

[lmf22]

Quote:

Originally Posted by breez /img/forum/go_quote.gif Can't you use the volume control in Foobar?

I wanted to get bit-perfect out. Adjusting the volume control makes it not bit-perfect.

I tested it with a DTS 16-bit 44kHz file: When I move the volume to anything other than 100% I hear only noise from my receiver. The hard -6db limiter doesn't affect the DTS file.

By the way: I have the Chaintech AV-710, so there's no ASIO driver.

 

[breez]

If the hard limiter was doing anything it would alter the data and make DTS CDs unplayable.

 

[thomaspf]

A hard limiter clips the signal range which is a conditional operation. If the DTS signal stays within the clipping range it will be unaffected.


However, why would you want a hard limiter to begin with since many modern music is mastered rather hot and will inevitably clip with this setup?

Cheers

Thomas

 

[lmf22]

I want to use a hard limiter to decrease the output volume so that I can get more range on my volume control of the LDM+. For example, without limiter turning the volume up just a tiny bit on the amp will make the volume increase a lot. With -6db limiter I can get a bit more range on the volume knob before it gets too loud.

Am I approaching this from the wrong direction? What other ways can I do this without using hard limiter?

 

[skitlets]

Attenuators, but I'd be more inclined to lower the volume via software than to add more components to the system.

 

[joe_cool]

I don't know what LDM+ is but I do know about analog and digital attenuation.

If you set your "bit-perfect" playback to 24-bit then digital attenuation (foobar volume control) won't affect your 16-bit unless you get way down past -40 db attenuation (24bits - 16 bits = 8 bits = 2^8 = 256; 20 * log 256 => 48 db.

Analog attenuation (resistive potentiometer) will basically raise the noise floor but in theory it will not otherwise alter the sound fidelity.

 

[thomaspf]

Quote:

Originally Posted by lmf22 I want to use a hard limiter to decrease the output volume so that I can get more range on my volume control of the LDM+. For example, without limiter turning the volume up just a tiny bit on the amp will make the volume increase a lot. With -6db limiter I can get a bit more range on the volume knob before it gets too loud. Am I approaching this from the wrong direction? What other ways can I do this without using hard limiter?

A hard limiter is the wrong way to go about this. It does not affect the volume in any way until you hit the treshold and then it just clips. So the end result is that your dynamic will get chopped up badly. You have full dynamic up to the treshold and then everything stays equally loud. I don't think that is what you want.

I would try to extend the signal to 24bits and then use digital attenuation. While this does not change the resolution mathematically since all bits are preserved you will likely take a hit on the noise floor. There are no DACs with 24 bit analog resolution. The very best models have a round 20 bits. The lower bits are drowned in noise and by using digital atentuation you are pushing the lower bits of the signal into the noise range.

However, to put this in perspective you need to look at your amp. The LDM is advertized with a THD+N value of 0.1%. This translates into -60db or roughly 10 bits of clean resolution, so the lower 6 bits out of the 16 bits from CD music are already being drowned in noise and distortion by your amp.

The 24 bit extension route will probably work well for you.

Cheers

Thomas

 

[lmf22]

Thanks for all your inputs. I think I have a better understanding of the situation now, and adjusted the following settings.

Foobar2000 volume: -11.40db
iTunes Multi-plugin Foobar2000 pass-thru "Maximum Volume" at 35%

Now I get much more range on the volume control of the LDM+.

Would it make any difference if I adjusted the volume of iTunes instead of Foobar200, or is it just the same? Right now the iTunes volume is at 100%.

 

[thomaspf]

I guess the answer depends on the way Itunes hands the music to foobar. If that happens as a 16bit stream then any attenuation lower than 100% will result in loss of resolution.

You will want to select 24bit output format in foobar and then rely on the digital attenuation after the format has been expanded.

To be safe I would leave itunes at 100%, the pass through level at 100% and do all the attenuation in foobar.

Cheers

Thomas