I prefer to use a hi-fi or entertainment contrivance that already has proper external speakers and better bass/treble controls.

Bass and treble ? I have a design that will blow your mind. If your public email is good I'll send you the print. Once I find it.

We are talking +/- 20dB, bass turnover continuously variable from about 40 to 400 Hz, treble has the same +/- 20dB with the turnover continuously variable from about 3KHz to 7KHz.

The only thing I am working on now is to decrease the effect of the treble when the turnover is lowered, meaning it boosts more frequencies. The reason is that if you got it set to 7K that 20dB boost is not that much, it is just bringing to you that sweet timbre. Take it to 4KHz and we are talking blowing tweeters fast like. So when I am done it is only going to have +/- 20 when set to the highest turnover.

Actually I am pretty sure I can just put some cutable jumpers on the board to allow the full range at all settings for those who get their tweeters wholesale...

It is a different approach to tone controls and I think I saw it implemented in some unit somewhere, but not as advanced as mine. No variable turnover..

I used to have the circuit values figured out but I lost it dammit. Doesn't matter I can figure it out again fast enough.

Actually if I get it up and send it you'll see because of the topology the values are very easy to figure.

Worse comes to worse I got it on paper and I can just scan it, where it was anyway, there is no Spice file of it.