Stereo System Upgrades

[toyotafreak]

Cal, just being nosey, but, GET A COVER ON THAT CAPACITOR!!! Drop one metallic or fleshy thing across them posts and you'll be picking copper shrapnel out of everything.

End of rant. I'm just jealous that you guys have time/money/weather to be playing!

[phenom_1819]

Never thought to do that.  But you're probably right.  Interesting because I paid a shop to do the install -- I wonder why they didn't do or mention anything to me. I couldn't get into that compartment because of a shoulder injury from a few years back, and had to pay somebody to do something that I've done way too many times myself.  Oh well...

[toyotafreak]

In my last job, we maintained a proton synchrotron (www.optivus.com). The packets of protons are steered by magents, and magnets are powered by DC current generated from AC supply.

Anyhoo, in the synchrotron area, the huge magents were powered by three or four power supplies that were ganged together. Memory fails, but they were like 3000 amps at 40 volts, or 120 kilowatts each, and would ramp from zero to max in like 2 seconds. The wires were actually 3" diameter copper pipe, with a 1" inside diameter through which chilled water was flowed to keep temperature under control.

Next anyhoo...each of these supplies needed clean output power, and caps are how you clean DC. Instead of some monster 50-pound capacitor, they just ganged like 20 of them caps you got on the X22. One of the supplies was unstable, and pushed its caps really hard.

Even though the walls in the facility were hardened to contain radiation, when that bank of capacitors blew, it felt like Bush had just dumped a JDAM down the chimney. BOOOOOOOOOOOOOOOOOOOOOM.

Final anyhoo....don't mess with caps. They're evil and must be treated with respect. They'll store up a buttload of energy and when shorted, can dump 63.5% of it faster than you can say "OJ did it".





That being said, I've never rigged up a car stereo cap, and maybe it's mounting makes it less dangerous.

[Chris A]

Hmm, makes me think of that time I got blown out of the hood of my lifted Chevy by my Super Coil(BIG CAP for the ignition system).  20,000 volts of FUN  The truck was on an 8" lift with BIG ol Mudders on it.  My friends say I flew a good 5ft out of the hood so it was quite an eventful 2 seconds of air time for me.  Anyways, after my heart restarted, my arm stopped twichN and my friends stopped laughing, I felt some Rum was in order, which made it all better    AH COLLEGE!

[cyclone]

I worked on a radar in the Nav with a 55kv DC supply for a travellling wave tube. It had banks of huge caps like that and they sound like a grenade going off when they pop!

[cyclone]

I made a new sub enclosure. It matches the slope of the panel kick panel. It slides right into the opening behind the panel. I'll post box plans if anybody want them. 

[cyclone]

Well, my 80 hour weeks paid off, I got a big award and a bonus from my company. So, I'm buying stereo equipment like a mall chick with daddie's visa.

First purchase, an Alpine CDA-9831 deck, plays MP3's and the XM interface is on the way.

My old Kenwood deck, Skippy, my 10 disk changer and Cal's old Kenwood deck are free for the taking, see the classifieds. Cal, your changer was toast, I destroyed it trying to get the cartridge out. That's what happens, hit one too many D'ups and the cartridge gets jammed, end of story.

[phenom_1819]

Well thanks for giving it a shot, Pete.  Sorry it took me so damn long to get you that harness. 

Oh, and I never posted a review of my new deck, the MB Quart NRA-450 marine deck. So here you go.

IT FRIGGIN' RULES.
30-second anti-skip buffer (works great)
adjustable/crossoverable inputs.
Adjustable-volume-level aux input (believe it or not)
5V in/outputs (I think)
It has a knob (#1 most important feature)
Display is farily easily readable in sunshine (better than most)

WHAT MORE TO SAY? I highly recommend it. I did a bit of searching and found it on ebay, refurb'd directly from RockfordFosgate (HighDesertAudio on ebay) for $200.  SWEET deal.  At $400, this deck would be a bargain.

Also, I rigged up some inputs/outputs like Shawn.  The inputs are on the lower lip of my dash, below the deck.  The outputs are mounted stealth up-high on my mid-ship speaker pods, where they are completly unnoticable, out of the way, and close proximity to the base of the tower (for running the RCA line up and over towers to another boat).  I got a 36' RCA patch cable from Radio Shack.  Will post pics soon.

(sorry for yelling, I got excited)

[cyclone]

No problem Cal, I woulda used the deck but I am flush all of a sudden, so a new one it is. I'll make sure that your deck goes to an Epic mariner out there somewhere, probably Lesman. He's definitely earned it!! Along with my changer, Skippy Jr.

I looked at the MB Quart, which is just like the Rockford Fosgate. Not sure who begat who, but I'm sure it's damn nice. I went with the Alpine because it plays MP3's and has some other features I really want, three outputs and a dedicated sub fader, and a frigging KNOB. And it will do XM, which I am addicted to. Now, I'll have to get rid of one of my three Sony standalone XM receivers. Hey, it's only money, make more next week, right?

I'm gonna do the IO thing too, gotta have it for when we're all rafted up together. As long as the guy providing the output is not a Kenny G. freak or something. Or a Young Country fanatic. Although, I am a Michael Bolton fan. I celebrate the guy's entire catalog....NOT

[cyclone]

Well, I got most everything done today, it was 77 deg all of a sudden and my boat was still torn apart. I shoulda been out there. ANYWAY, I got a buncha Polk Momo 6.5's, they fit in the stock locations on Epics, which have a 5" hole. The factory Kenwoods are 5.25's but have a footprint the size of a 6.5. Actually, the Kenwood grille is about 3mm bigger than the Polk 6.5's but the speaker is much wimpier. I now have 4 Polk Momo 5.25's that are going on Ebay (again!)

They sound great!

[cyclone]

I had to use a sanding drum to open the holes on the rear panels to get the speaker terminals through. The panels are sandwiches of five layers of starboard synthetic wood, pretty heavy duty. The holes line up more or less but in the front I had to epoxy and redrill to make the grilles straight.

I got some cheap molded foam baffles that fit the back side of the speakers, epoxied them in place to make an enclosure for each speaker. Ordered four, they sent me eight. Good thing, I screwed up a couple of them!

[toyotafreak]

Molded foam baffles...does that help keep the speaker from distorting, or does it just keep stuff off the magnet?

Have wondered for some time how much better little speakers like this sound (as far as bass repsonse and delaying onset of distortion) when they're placed in a small enclosure. With subs, one of the main things an airtight box will do is keep the speaker in a mechanical suspension, right? This keeps the woofer cone from over-travelling either in or out, and seems like it'd surely apply to smaller speakers.. I tried to get T/S parameters on 6.5's and 6x9's from Infinity and all they'd give me was like a rough guess (think it was like 0.2 cu.ft. for the rounds and 0.3 for the ovals, as opposed to 1.0 cu.ft. for a 12" sub).

Pete, your setup's coming along nice. Keep us posted :-)

[phenom_1819]

The foam baffles are mostly just to keep stuff off the magnets... an enclosure will help a lot for sound quality if you can make the enclosure big enough. Pete, I'm guessing you got the ones from Crutchfield?  I had those in an old VW hatchback of mine.   If I recall, I liked the sound a touch better without the baffles, but with a subwoofer, it really doesn't matter.  Most car speakers are designed to run as if they were free-air anyway.

[cyclone]

I got them from a wholesaler that I buy lots of stuff from, mcmelectronics.com I figure that it will make a little more sound come out the front, rather than cancelling out bouncing off the back. It's splitting hairs, really.

I might keep a set of the 5.25's for the dash.....

[shawn]

Next weekend will be the start to my new system.  Four 12's in the rear trunk, one under the dash, both with separate gain controls.  The four in the rear will be off while cruzing and then when it's time to shut everyone down, flip the switch for the dual linear actuators to lift the rear locker hatch straight up and turn on the subs.  Should be cool, as you can tell, i am never satisfied, always trying to do something original.