As mentioned earlier, it's normal for people to want to boost the bass (and treble) when listening at low levels. Many receivers have a setting--usually called "Loudness"--that does exactly this. The iPod has an EQ preset that does the same thing. It won't boost the bass by 9 dB, like you're doing now. In fact, the Bass Boost preset gives you only 6 dB more bass, and on some older iPods, it can produce audible distortion from clipping.
What you really want is a customizable equalizer. If you had an iPad or a newer iPhone or iPod Touch you could just download an app. For very old iPods, you can get custom EQ by installing the Rockbox open source firmware. Unfortunately, the 5th generation iPod Nano isn't listed as one of the supported models.
The problem with buying the E7 blind is that it has only 3 fixed bass boost settings. How will you know for sure that one of them will work? I suppose you can look at their frequency response graphs and simulate them with your computer. You'll have a similar concern with any other portable amp, DIY or otherwise. You may be better off getting a cheapo player that has adjustable EQ. A refurb Sandisk Sansa Clip+ or Fuze can be had for $25-$30. Just drive over to the CompUSA on Hillsboro and Military in Deerfield Beach and pick one up. The Clip+ and Fuze have 5-band graphic equalizers, and if that's not flexible enough, you can install Rockbox or return them.
So argue like this:
- You want to protect your hearing, so you want to listen at low levels.
- At low levels, most people don't perceive as much bass and treble. Show him some equal-loudness contours at various listening levels. The original ones are called Fletcher-Munson curves.
- Because of #2, a suitable loudness EQ setting is needed. Tell him that most receivers have this feature.
- Unfortunately, the 5th generation iPod Nano's Bass Boost and Loudness EQ presets don't have a pre-cut so they result in distortion due to clipping, regardless of the volume level. You'll have to supply some online research to prove this. Otherwise, learn how to use RMAA and Audacity so you can create your own test tones and run some tests. Better yet, let him hear the distortion from the iPod.
- Therefore you need a player that has custom EQ.