Pre-Out Voltage Q

[MentatGom]

Hey All,

I currently have a Kenwood headunit with 2 volt Pre-Amp Outputs.
This is run to a 300RMS amp (with gain almost all full) powering a 10" sub.
When I am running the headunit at high volume (~15) the sub sounds great and balanced with my Highs and Mids run off the headunit. But I don't want to go deaf listening that loud.
At normal listening levels (~5) the sub is barely if at all audible.

My Question is whether a headunit with higher voltage pre-amps will offer more output at lower listening levels? Otherwise I am going to return this amp and subwoofer. It is past my return date for the headunit, so I have to live with it for now.


Thanks!

[Monkeyman]

Higher voltage won't make your stereo louder, but it will make it play cleaner at higher volumes (on the head and the amps). Higher current (current = Amperage) will make it louder. As you turn up your head units volume the current increases, but the voltage usually stays about the same. You could kill two birds with one stone and buy an Audiocontrol EQL, EQS, or EQX, which will up your RCA signal's voltage to 5 volts (max of 13 volts), AND give you a graphic equalizer to improve your sound quality.

Here is a link to Audiocontrol's website for these 3 models:
http://www.mobileaudiocontrol.com/dept. ... 48&l1=5248

Hope this helps,
David

[blaK]

I know this is old but I know what your talking about, I changed 10" to a 12" and it's night and day.

[Monkeyman]

A 12" sub has a larger surface area and can therefore move more air.
This isn't the only possible reason for the improved sound though.
The new sub may have a shape which is closer to parabolic (focusing the waveform on the parabola's "focus" allows all -or most- of the air to join together resulting in "more punch"). There is a potential downside to a parabolic cone shape though, and that is the sound wave doesn't spread as well as it could. For a subwoofer this isn't so much of a problem because the human ear cannot detect the directionality of most low frequency sound.

The enclosure you had for the 10" may not have been the right size for the sub. This is detrimental to the sound quality. To small and the sub won't play the frequency sent to it, AND it will move too hard. To large an enclosure and the sub won't move properly (to little mechanical forward movement) and will sound boomy, muddled, and out of frequncy. Your new 12" may have a better enclosure.

Your new sub may have a higher efficiency, so more sound can be produced from the same amount of power.

There are numerous other reasons (cone stiffness, enclosure rigidity, voice coil material and resistance rating -8, 4 or 2 ohms on the nose whereas the old sub may not have been- and on and on....) which effect the differences in sound quality and SPL. This is one reason why I always tell everyone on the forums to listen to EVERY sub (and speaker, and amp, ect.) they can, and write down everything they like and dislike about each while they are listening to each (using the same piece of music every time). A spectral decay graph helps some too, although head units, wires, amps ect. can add "coloration" to the sound.

A well listened and researched ear will be a happy ear!

David