Digital Signal Processing (aka Equalizer)
DSP seems to be a catch-word. Back when I was younger - all sorts of equalization was done with resistors, capacitors and chokes (discrete electronics) and the occasional transistor or vacuum tube (the good stuff..) Now it's done digitally. I'm not saying it's a bad thing, but it does seem to add a lot of complexity to what might otherwise be a simple thing to do...
The default DSP screen - is accessible from several audio apps (and as a stand-alone app). This is the opening screen for it:
What do I see - BUTTONS with LABELS! YEA! This entire app must have been written by someone other than the label-less default apps. If it had options for some different colors it would be really attractive.
This screen is kind of curious - you can move sections of the display by clicking and dragging them around. I didn't really hear much difference in the audio when doing this, so it's not clear to me what it does. The FC scale at the bottom appears to represent frequency, the scale above that says "Q" - but all the values are 4.0, and don't seem to change with movement of the curve above them. So - I'm puzzled.
The left-most-top button opens predefined patterns like "User, Rock, Jazz, Classical, etc..) none of which I found particularly appealing. "LOUD" is a loudness setting, and default sets the curve flat.
Happily, my confusion was cleared up when I pressed the "Switch" button:
HEY - look at that - an "Equalizer" screen (makes sense - button selected is "EQ". That's pretty understandable. Still has the puzzling Q scale (and no explanation of what it indicates), but it's pretty easy to shape the frequency response using this. I sorted that out to what I liked, and then pressed the "Field" button:
OK, that's pretty simple. It adjusts the sound "Field" - ie - volume of each quarter of the car. You can adjust it by draggng the center dot around, or using the << and >> arrows. I left it pretty much centered. And moves on to "surround":
Well - here we have a time-delay feature, that I imagine is supposed to correct for the time error if a note was played in all 4 channels at once - to the user/driver's head. Somehow I think this is unnecessary in our cars, and they could likely all be turned off. I've gotta do that sometime - the settings showing are the default settings.
It's an interesting idea, and I guess a swell thing to do if you can do it, and if you were in a large van with speakers in all 4 corners it might actually be useful.
I pressed onwards to "Stereo Sound Enhancement":
No clue. I'm totally unclear on what these are supposed to do. If anyone has any ideas please let me know. I think the setting here are after I played with it (and heard no discernable difference in the sound) - I think "Default" was pretty much all of them at the same low level. Well - since that left me baffled - I moved on to "Bass Enhancement":
OK - this one I sort of understand almost. It allows you to change the volume of either the front or rear set of speakers at a certain frequency. So if you had honking big woofers with an amp as the rear speaker set you could jack this up and rattle cars next to you, without overdriving the front speakers. I guess it has a function. I think I left it at "Default"..
Sound Filter - sets upper and lower limits for the amplifier. Handy for systems where too low frequencies cause issues.. and it can be used to make the front and rear speakers have different frequencies fed to them. Think of them as high-pass (HP) and low-pass (LP) filters.
On a scale of 1-5, I'd rate the DSP as a 4. It has BUTTONS with TEXT. The options it offers have more capabilities than I think I'll need (I'm an old-fashioned tube audiophile, who usually ran my bass/treble controls at zero. Once in a while I'd turn on "Loudness" though.) but for the guy who likes to tinker with the sound, it seems to offer a lot of possibilities.