Audio Book mastering - comparitive analysis

Question

Hi all, i'm fairly new to Audio Book mastering. Ive just prepared a file for a title i'm working on through acx.com for audible.

I've mastered it according to their specs... what i then like to do is listen back through my laptop speakers to make sure it's clear and audible in a less-than-perfect setting.

It sounded to me like it was lacking in clarity and needed a level boost. So, out of interest i downloaded a sample from the audible website (actually i found it elsewhere since they don't allow downloading of samples) and did an analysis through Audition.

The first thing i noticed was that the peak level is -1.28 db. This is much higher than the acx specification of -3db. Experientially the sample is also much more compressed sounding than my file and hence louder overall. This makes me wonder if audible deliberately boost the peak level on their samples, i have yet to find out if this is true.

However, having boosted the peak level of my file for comparison, the other stats like total RMS and Loudness are very similiar to my file. And yet, as can bee seen from the waveform, my file is much lower on overall loudness, perceptively speaking at least.

In order to get my file sounding more like the sample file in overall loudness i added some compression and extra EQ to mine, but when i then analyse this new file, i find it exceeds the RMS values in the acx specification (-23db to -18db) by four or five db.

So my question is - how is it possible for the audible sample to be so much louder and clearer perceptively and yet maintain similar stats to my file?

Here is the analysis of the sample from audible:Bk Potr 000008 Sample by Ways Of Wonder | Free Listening on SoundCloud

Here is the analysis of a sample of my file: Ashik Kerib Sample by Ways Of Wonder | Free Listening on SoundCloud

ryclark · Answer

Having taken a quick listen to both of the above examples I can hear that there is a lot more lower mid frequencies in your recording. This will possibly add into the measured loudness as well as 'muddying' the sound especially when converted to .mp3 and listened to on smaller speakers. Also looking at the two waveforms is a little misleading since their example is almost 5 minutes long and yours is only 1.5 minutes. Thus theirs looks 'denser' than yours.

Here is what the comparison of the frequency analysis looks like with the red line being theirs and the green line yours. You can make yours better by rolling off some of the low frequencies below 200Hz and lifting the high frequencies by re-EQing your file. It should then sound brighter and a bit lees woolly on your laptop speakers.

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