mpollan

I still need to do some tuning but I have no idea what does what. I baselined per a previous thread (volume ~ 75%, 80Hz, turn up gain until dstortion an back it off a bit). It sonds pretty good but I know it could be better if I knew what I was doing. Said/asked differently, what does each of the amp controls do to the sound. Also on the subject of sound, when I rip my CDs to the Phatbox they sound really flat compared to FM broadcast. I am burning at a 192 bit rate at 44k Hz using the Phatbox music manager. Suggestions on how to improve the quality?

Thanks in advance,

Mark

ohbw

Mark,

I believe I was the first guy to do this, and I've done it twice now, and I don't think any kind of rule of thumb can be laid down for settings because every amp and every sub of different power / size is going to meet up with every head unit not to mention every style of music differently -- Bob Marley and bluegrass aren't the same signal at all.

Fundamentally, you want to lower (quite low) the bass signal at the head unit, and you want to lower (to zero) every frequency but the bass frequencies at the sub amp. Those you'll turn up quite a ways. The point is to take a small bass signal through the system (so the other speakers are receiving almost none and can devote themselves to mids and highs), and then to enlarge that small signal via your dedicated sub amp.

It took me hours of experimentation to dial mine in. Once it was there, I had a huge range of control at the head unit, just dialing the bass output in the 1-5 range there. But finding that critical sweet spot took a while.

Then my sub amp burned up in one channel about a year later. Replaced it with a different amp, and had to do it all over again, and everything was a little different to make that one sound just right. Then Apple changed some EQ settings in iTunes software, and I had to alter the settings I used on my iPod in conjunction with my A8 stereo!

I can change the speaker wiring on my home stereo from Naim to Linn and make people think they're listening to a completely different stereo. The closer you get to great sound, the more a little tinkering here or there can swing you one way or the other.

192 is a pretty low bit rate, though I have some things burned at that rate (using VBR) that sound fine in my car. I wouldn't want to listen to them in my house. I burn at 256 to my iPod these days. Using VBR makes a surprisingly big difference in the quality you end up with.

mpollan

My biggest issue is getting the Phatbox to the relatively the same levels as the FM broadcast. If I tune the sub for the Phatty then FM is way overboosted and vice versa. Using the bass control on the head unit might get me there, or at least closer.

Thanks again Brian,

Mark

ohbw

I don't know what the Phatbox allows in the way of EQ control, if anything, never used one. If you have tunability there, that would probably be the simplest way to bring its signal and the FM signal into the same ballpark.

The ear is a sensitive instrument. <b><a href="http://video.google.com/videoplay?docid=4078791286347934514&q=%22tom+waits %22+daily+show&ei=c55BSN63D4uUrgOpmbWCCQ">Tom Waits</a></b> lives in Sonoma and he has, as you might imagine, a kajillion dollar studio on his property. But when he feels like a song is nearly ready, he burns it onto 8-track and goes out to play it in the Coupe deVille that sits in his yard (and doesn't run). If it sounds right in the Caddy, it's done. If it doesn't, it isn't.

This is Nick Uranta of Devotchka ("Little Miss Sunshine" soundtrack, Grammy nomination, and not like any other band in the world). He doesn't use that mic setup to look cool, he does it because it changes the whole sound of the band.

It's like Gabor and the valve body! You have to go way, way down the rabbit hole to find Just the Right Thing.



<img src="http://pictureposter.audiworld.com/84266/nicklight.jpg">

mkurak

This is serious question, I'm not trying to poo poo your efforts.

mpollan

So much so that a rear seat passenger (I think I only had one) inquired if the rear deck speakers were disconected. Once you go sub you'll never go back.

Mark

skiracer

Please ;-)

mpollan

not total parity with FM but tons closer. The file size doubled so I am on the prowl for a bigger DMS cartridge.

Gratefully yours,

Mark

mkurak

Yeah, I'm sure that Bose has equalized the system to be neutral; that is, to not artificially accentuate any given frequency. If you are an audio purist; by which I mean someone who wants their recording to sound as much like the performance as possible, then that is how you want the system. Of course, noone records in two channel stereo anymore, so go nuts.

ohbw

10" JL Audio sub, nothing special, $99 I think, in a custom box, $50 or $75 I think (because it's smaller than the off-the-shelf boxes):

<img src="http://pictureposter.audiworld.com/84266/111.jpg">

Kenwood 250W bridgeable amp ($149):

<img src="http://pictureposter.audiworld.com/84266/222.jpg">

I put plugs in the wires from amp to sub so I could remove it on the off chance I might ever need every square inch of trunk space, but I've never touched them. It's just Velcroed to the trunk floor, but it's heavy enough that it never moves.

It sounds better where it's sitting than it did on its side facing the ski passthrough (note the four handy holes in the deck above it). I don't even open the rear armrest anymore; between the deck and the cracks in the pass/armrest, there's plenty of room for air to move, and that's all that's necessary.

I resist the idea that anyone needs to spend a bunch of money on this or have a high-powered amp driving a colossal sub. Good sound is about balance. My friend and home audio dealer sells very high end gear and drives an SL500 with a big-bucks Nakamichi set up in it, and every time we go to lunch, he says, "Jeez, your car sounds way better than mine."