Quickie for dennis

Post by **elwesso** » Mon Jun 07, 2004 6:17 pm

Do you know of any unused hole in the firewall that has a rubber plug in it...

I have my subwoofer ready to go, but I need to find the best place to run it through the firewall...

Post by **Q45tech** » Mon Jun 07, 2004 6:17 pm

You mean the battery cable for the amps-----most run under car and tie wrap to channels.

Post by **Rex** » Mon Jun 07, 2004 6:17 pm

I may show my ignorance (usually do when Dennis is involved), but I've been dabbling (from professional/job to hobby/enthusiast) since the mid 80's and I've only heard of 1 guy ever that ran his power wires outside of the car. And he used some nasty 3" PVC as a conduit

.

It's not uncommon for there to be "exrta" holes in a firewall (but I've never looked on the Q) that weren't used and simply filled with a solid rubber plug. Or maybe an existing entry point to the cabin that isn't "packed". Maybe were some wires/cables for the active might have passed through?

Post by **rsiwicki** » Mon Jun 07, 2004 6:17 pm

from the previous owner of my Q who was a stereo nut and had the stock system totally removed and a very nice custom job installed, but took it out when I bought it....they drilled a whole through the firewall right behind the brake pedal to run the power wire. I still have the nice monster cable going to the trunk....stereo system is coming next after all these performance mods.

Post by **elwesso** » Mon Jun 07, 2004 6:17 pm

Id like to avoid drilling if I could, mainly because I dont have stuff to drill that big of a hole at my house...

Post by **rsiwicki** » Mon Jun 07, 2004 6:17 pm

Well when I get my car I will look and see, but it is from what I remember just the size of about a 1/4" drill bit and not thick at all to get through the fire wall.

Post by **Q45tech** » Mon Jun 07, 2004 6:17 pm

Q have nice wonderful brake and fuel channels on the rails, one can buy armored #4/0 to run for rear battery applications.

Don't know how big a subwoofer amp you are speaking of feeding. Most of the monster systems we see have rear batteries, massive capicitors,

http://www.poweriseverything.c....html

At 30 amps peak #4 COPPER can be run 15 feet with a 2% voltage drop.

Post by **Rex** » Mon Jun 07, 2004 6:17 pm

Okay, now that you add the "re-located battery" logic, in the rails makes sense. But how/where do you get into the rails and how do you get back into the trunk?

Post by **elwesso** » Mon Jun 07, 2004 6:17 pm

No worries.. I got it ran...

I ran it with the hood cable on the drivers side... I have pictures and it worked out very nicely... Runs right by the transmission unit.

The cable for the hood moves inside of the casing, so it wont move around and potentially get stuff inside the car...... I ran it with the rest of the ECU wires that go in front of the radiator, etc to the battery... Its a really nice setup.....

Post by **Q45tech** » Mon Jun 07, 2004 6:17 pm

Perfect so that at high current loads it induces an electromotive field that could couple noise spikes into tcu/ecu sensor wiring.

Still don't know how much current you will have at peak.

Have you viewed the trash some power switching supplies in Class D amps create?

Post by **maxnix** » Mon Jun 07, 2004 6:17 pm

Geez, Dennis, some young'uns just want to thump til they're deaf. :rolleyes

Just because we are too old to appreciate really unbalanced, distorted bass frequencies...:thinker

Post by **elwesso** » Mon Jun 07, 2004 6:17 pm

Its maximum power output is 240w at 4ohm... Not really powerful at all..... Ill run it away from the TCU so its not as close.....

Post by **Q45tech** » Mon Jun 07, 2004 6:17 pm

Depends on the way the 240 watts is rated at the worst case it could consume 240/12=20 [corrected for bad or peak efficienct] say 40 amperes.

Remember the alternator only puts out ~~ 33 amps at idle and the car needs 15 just to run.......no lights no AC no nothing extra.

Post by **squeefoo** » Mon Jun 07, 2004 6:17 pm

MAX:" too old to appreciate really unbalanced, distorted bass frequencies." reminds me of about 20 or so years ago- some people pulled up next to me with the entire dash covered with 2-3" speakers glued on it. Both our windows were open, it was the most horrible, distorted, mess I think I've heard. I remember the whole car-ful bopping their heads to it. Some things don't change for better or worse. :rockon

Post by **Rex** » Mon Jun 07, 2004 6:17 pm

Q45tech wrote:Depends on the way the 240 watts is rated at the worst case it could consume 240/12=20 [corrected for bad or peak efficienct] say 40 amperes.

Remember the alternator only puts out ~~ 33 amps at idle and the car needs 15 just to run.......no lights no AC no nothing extra.

Amp has a 25 ampere fuse, so my guess is under normal to heavy operation it draws in the teens with spikes in the upper teens. Not ideal, but of course additional stereo (or any eletrical) draw on the battery isn't good for the life of the alt. The draw should be in "short" bursts (not even full second), unless he's listening to some speed metal

.

Post by **psychic_mechanic** » Mon Jun 07, 2004 6:17 pm

Q45tech wrote:Perfect so that at high current loads it induces an electromotive field that could couple noise spikes into tcu/ecu sensor wiring.

He's not kidding about that, we put a Buick GN engine into a porsche 944 that would run great when hooked to a scan tool, but not when driven without it.

After days of searching the too-simple problem was found, one of the spark plug wires off of the coil pack ran parallel to the ECU harness for several inches and was making the voltage for most of the sensors fluctuate.

Post by **Rex** » Mon Jun 07, 2004 6:17 pm

psychic_mechanic wrote:He's not kidding about that, we put a Buick GN engine into a porsche 944 that would run great when hooked to a scan tool, but not when driven without it.

After days of searching the too-simple problem was found, one of the spark plug wires off of the coil pack ran parallel to the ECU harness for several inches and was making the voltage for most of the sensors fluctuate.

Not that he shouldn't re-route the wire away from the ECU wires, but isn't the "voltage" as well as amperage of that spike significantly higher than an amplifier's power wire?

Post by **elwesso** » Mon Jun 07, 2004 6:17 pm

when I was debating where to put it, i didnt want it by the ECU and thats why its by the TCU... Still important but not nearly like the ECU

Post by **Q45tech** » Mon Jun 07, 2004 6:17 pm

Oh it is one of those MUSIC RATED Music peak CLASS D 240 watt amps not a real linear sine wave RMS continuous duty 240 watt amp which would draw over 500 watts [40-50 amps].

These are really 60-75 watt amps [from an engineering point of view]and draw 10-11 amps average why the 25 amp fuse.

Automotive fuse are usually double to triple the average continuous drain.

Post by **szh** » Mon Jun 07, 2004 6:17 pm

maxnix wrote:Just because we are too old to appreciate really unbalanced, distorted bass frequencies...:thinker

Not me!

I do not consider my car(s) to have excellent audio. My home system provides me that.

Bass is handled by a Velodyne ULD-18. This is an 18" subwoofer, powered by its own 400Watt amp, and servo-controlled speaker. The speaker has an accelerometer attached on the 3" voice-coil that is tied into the feedback system of the amp. Gives me clean, undistorted bass down to 15-20 Hz without any problems!

Z

Post by **qship96** » Mon Jun 07, 2004 6:17 pm

szhosain wrote:Not me!

I do not consider my car(s) to have excellent audio. My home system provides me that.

Bass is handled by a Velodyne ULD-18. This is an 18" subwoofer, powered by its own 400Watt amp, and servo-controlled speaker. The speaker has an accelerometer attached on the 3" voice-coil that is tied into the feedback system of the amp. Gives me clean, undistorted bass down to 15-20 Hz without any problems!

Z

excellent sub! I have the uld-15 series 2,also with the servo controlled 400 watt amp,while vandersteen model 2`s handle all the mids and highs the adcom electronics feed them! i agree,car sound systems cant hold a candle to true high end home audio-why even bother upgrading,just to worry about aesthetic and theft problems!

Post by **szh** » Mon Jun 07, 2004 6:17 pm

The Vandersteen 2's are very, very nice, for sure!

I used to have electrostatics (Acoustat Model 2), but decided to sell them when my son was born (did not want 5kVolt screens hanging around an inquisitive toddler.) Now, for now, I have Kef Studio monitors driven by a dBx-2 amplifier (400W/chan).

Someday, I will get electrostatics again, but for now, the sound is just fine. Extended clean bass and clean mid/treble (the Kef's do not have "bass port" for artificially doubled heavy bass) cannot be beat!

Anyway, back to the topic after this digression that I started. Sorry about that!

Z

Post by **qship96** » Mon Jun 07, 2004 6:17 pm

i have always admired electrostatics! have a pair of stax"earspeakers" that i enjoy,but have always lusted after a pair of martin-logans or maggies!

Post by **maxnix** » Mon Jun 07, 2004 6:17 pm

Just old McIntosh stuff here, but my PC speakers are electrostatic Monsoons.

Post by **elwesso** » Mon Jun 07, 2004 6:17 pm

So dennis what your saying is its not that big of a deal (or not as maybe)...?

Its a very small setup but its still fine for me..

Post by **Rex** » Mon Jun 07, 2004 6:17 pm

Just 1 point I'd ike to make to all the "digression discussion", not all in car stereo is as bad as the masses "displays". You can achieve a good balanced audio system inside of a car, it just takes much more effort/design.

Car Audio is not an oxymoron, it's just most of what you "hear" from other cars is from morons

.

Quickie for dennis

Quickie for dennis

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