Some older boomboxes from the mid 80s and before have a "brighter" sound which I like.Others have what I call a "darker" sound like my Prosonic PQR-9962.If these boxes have only bass and treble controls,this sound characteristic cannot be modified.However if a box has a multi-band equalizer,I've found that tweaking some of the middle sliders does modify this effect.For this reason,lately I've been playing with putting a home graphic equalizer in between a portable CD player and some of my "darker" sounding boxes line-inputs.This works nicely to give me that effect on the sound.

Experimenting with the equalizer causes me to wonder what might be different about similarly sized boxes with only bass and treble tone controls.It occurred to me that the capacitors which filters out the bass frequencies before they reach the tweeters could play a big part in determining the presence of the middle frequencies.Different caps with different ratings should affect which set of drivers handles the mids and how prominently they are reproduced.Now I am wondering if replacing the 9962s caps with the ones from my very bright sounding KTO (Kasuga made) box might make my 9962 sound similarly bright also.Can a mod like this really have an effect on the sound?Was this the main reason for this difference in sound I hear from some boxes with close to the same sized drivers and power ratings?Someone please edumacate me

jovie i had the same thinking especially the sharp gf-9696 series,nice looking box loud but lacking deep bass responce,,i would have liked it to sound like the bass of the gf-777 i have been temted to mod mine...

Cap values will go some ways towards modeling the sound but changing caps especially cap brands really only begin to show their benefits in higher end audio and higher voltage applications such as guitar amplifiers. Basically when you're running more voltage it becomes much more apparent and I'm not sure if it would really make much sense to change cap brands just to mold your sound.

However changing values will determine what is the cut off point for the frequency that will pass to the tweeters. Naturally for most applications there is no upper limit but you certainly want a lower limit as you don't want your tweeter trying to reproduce bass frequencies. This won't really make much effect on the brightness of the box.

If there are any capacitors near the tone control then this is where changes can be made. Some audio designs have "bright caps" which are used to bring more treble back at lower volumes as the human ear is less sensitive at lower volumes to certain frequencies(Google "Fletcher-Munson Curve")and so this cap tries to rectify this. Some people complain this causes for an "icepick" sound to occur at lower volumes and either change the cap value or remove it completely.

However do realize that MANY other factors play a factor in tone characteristics of an audio circuit. The op amps used in amplifying the signal have their own tone signature as do the speakers that reproduce that signal. Additionally even such things as the gauge of the wire can change the tone of a circuit. In the case of boxes the placement and tweeter type play a large role as does the porting of the box in reference to the woofer.

Changing just one component generally won't change much in a lower voltage and wattage application such as a boombox. Generally multiple changes(cap value change,speaker/tweeter change)are required before results are heard.