IPB

Welcome Guest ( Log In | Register )

Applying Gain to 16-bit Recordings
Engelsstaub
post Jul 18 2012, 11:07
Post #1





Group: Members
Posts: 556
Joined: 16-February 10
Member No.: 78200



I have a few questions regarding some 16/44.1 recordings I have that could be a bit louder. I wanted to boost the gain to somewhere around the point where peaks will be around -1dB without clipping. (It seems that typically the peaks are around -3dB and the meat of the recording is around 6dB and often lower.)

The files will first be upsampled to 32-bit(float)/44.1 and edited in iZotope RX2 Advanced. (Editing consists of light declicking, some possible noise removal between tracks, etc. and then resampling/dithering back.) My questions are these:

1. Is there any reason why applying gain would effect the quality of the original recording in the resulting product? (Would it have just been better to get the level set closer in the first place tongue.gif ?) I know that reducing the volume is "losing bit depth," as I've read this from members in older threads while searching earlier. Is there a reduction in bit depth (or perceivable sound quality) when increasing the volume when using a quality program at the upsampled bit rate?

2. Should the gain be applied before or after the editing (or does it even matter) assuming that number one isn't a boneheaded way to approach this with respect to quality?

Basically I believe it would be ideal to make this...



...look about like this. (About 3dB louder.)



(Sorry if these questions are a bit noobish. I've been reading my ass off through the archives and still can't quite get a grasp.)


--------------------
The Loudness War is over. Now it's a hopeless occupation.
Go to the top of the page
+Quote Post
 
Start new topic
Replies
Engelsstaub
post Jul 19 2012, 09:39
Post #2





Group: Members
Posts: 556
Joined: 16-February 10
Member No.: 78200



Andy: Thanks. I guess I should have known that its best to normalize last. Especially when I need to declick and do other stuff to the files.

Porcus: I would have ideally liked to have recorded at 24 bits but my preamp's USB out is USB 1.1 protocol. (Pro-Ject Debut III USB) I plan to make necessary changes to my hardware in the near future but until I do I'm stuck with 16 bit...I wish I had known that before I purchased that TT. (I can use a RCA to headphone jack cable directly to my MacBook Pro's soundcard @ 24 bits but I have a feeling USB would be much "cleaner.")

Also I'm using iZotope RX 2 on OS X so Foobar's out for me. (I do have a Windows PC but it has issues that preclude me from wanting to use it for much.) If you're wondering about the album peak in the case of the album in my illustration, I scanned all of the tracks in iZotope RX and found it to be exactly -3dB. There was something closer to FS but upon inspection it turned out to be a "pop."


--------------------
The Loudness War is over. Now it's a hopeless occupation.
Go to the top of the page
+Quote Post
Porcus
post Jul 19 2012, 12:13
Post #3





Group: Members
Posts: 1842
Joined: 30-November 06
Member No.: 38207



QUOTE (Engelsstaub @ Jul 19 2012, 10:39) *
my preamp's USB out is USB 1.1 protocol. (Pro-Ject Debut III USB)


The turntable-with-preamp? It has a decent reputation at the price mark.

Your postings indicate that you have not done any volume adjustment at all, in which case the ProJect recorded your LPs with a peak at about -3 dB. That sounds to me like it has employed a reasonable volume for its ADC. No reason to change that, really.

I read that the ProJect's RIAA preamplification cannot be bypassed; that means that if you record by soundcard, it is only the (presumably) “easiest part” of the groove-to-digital processing that you replace. You cannot expect much improvement then. You might of course record through both and perform a listening test, but I would be (mildly) surprised if you get any “wow!” experience at equal volume. (Can the ProJect output to both RCA and USB simultaneously? Then you could timing-align them and ABX.)

The Ortofon OM5 is an entry-level pickup, so unless the sound clearly indicates that you should do the process over again, then I wouldn't re-record unless I had replaced the OM5 with something better. However ... the following is due to my lack of knowledge on the ProJect's internals, but I would be careful: as the ADC seems to process at a reasonable volume with the OM5, then how would it perform with a different pickup with a different output level? If it adjusts volume (... which I doubt, as I think it is a bad idea to implement), then nothing would change. But if it is simply set at the OM5's max out, then you don't want a pickup with higher output level (it could cause clipping). Your initial position was that 3 dB is wrong; actually, I'd guess that those 3 dB are really the ProJect's healthy margin of error.


I'd say ReplayGain it smile.gif

This post has been edited by Porcus: Jul 19 2012, 12:18


--------------------
One day in the Year of the Fox came a time remembered well
Go to the top of the page
+Quote Post

Posts in this topic


Reply to this topicStart new topic
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:

 



RSS Lo-Fi Version Time is now: 24th July 2014 - 05:32