Audio recommendations

[michael hurd]

Firstly, I knew the area under the rear seat was minimal at best, but I had no idea just how little room there actually was. Secondly, it turns out, I DO have power seats (full power adjustable driver, power lumbar for the passenger), which means the amp under the driver seat is not going to happen.

So, I've decided to build a center console with a sub enclosure and a spot underneath for the amps. Problem solved.

The only real question I have now is do I make the sub fire down, or fire towards the rear?

You could swap the full power base out for a manual base on the driver's seat.

As far as orientation, if the cone is heavy with a light suspension, you will get sag over time, limiting your outward excursion. There is a formula for this: Percentage of Sag = 24,849 / ( Xmax * Fs²)

If the percentage of sag is more than 5% of the xmax, then it is not recommended to mount in the vertical position.

Downfiring will introduce some low pass effects, in essence rolling off the top end of the response. It does tend to protect the cone from accidental damage.

When running your power wire for the amplifers, make sure you include a fuse holder as close as possible to the battery.

 

[RawbDidIt]

You could swap the full power base out for a manual base on the driver's seat.

If I was the only driver, that would probably be my move, but my girlfriend is really short (I'm 6'1", she's 5'1") so the power seats are a nice feature for her. Also, I'm not a huge fan of the center console anyway, and if I build a console, I can keep my amps more enclosed and prevent accidental damage from somebody in the backseat trying to get a more foot room. Don't worry, I plan on making sure there's plenty of airflow, I may even mount a couple of fans for the amp enclosures.

As far as orientation, if the cone is heavy with a light suspension, you will get sag over time, limiting your outward excursion. There is a formula for this: Percentage of Sag = 24,849 / ( Xmax * Fs²)

If the percentage of sag is more than 5% of the xmax, then it is not recommended to mount in the vertical position.

Downfiring will introduce some low pass effects, in essence rolling off the top end of the response. It does tend to protect the cone from accidental damage.

Never even thought about this, that pretty much makes my mind up for me. It's much closer to 15% of Xmax. I'll likely set it a couple inches inside the console, rear firing with a slight upward angle to it, and definitely put a grille over it.

When running your power wire for the amplifers, make sure you include a fuse holder as close as possible to the battery.

This one I knew I'll put the main fuse somewhere discreet, probably the wheel well, run that to a power distribution block (fused) in the console, then to the amps.

Since I'm doing all this work, I might rip out the carpet to make it easier to run the wires, and install some DynaMat while I'm at it, reinstalling the carpet once I'm done, of course. Does anybody happen to know if it makes a huge difference in the floor, or is the carpet enough to deaden the sound for normal use, or should I focus more on the rear wall and doors?

 

[michael hurd]

Without a carpet and seats, it is much easier to route and run wiring.

Yes, 15% of xmax is a considerable amount of lost excursion. Once the suspension sags, it is permanently deformed, and will not return to it's normal center position, even if mounted horizontal again.

The coil will not be centered in motor properly, and the suspension kms curve will reflect this as well.

Follow this link for more information:

https://www.klippel.de/fileadmin/klippel/Files/Know_How/Literature/Papers/Klippel_Nonlinearity_Poster.pdf

 

[michael hurd]

Does anybody happen to know if it makes a huge difference in the floor, or is the carpet enough to deaden the sound for normal use, or should I focus more on the rear wall and doors?

I would focus more on the doors and the rear cab wall, might want to replace the window run channel and window belt moldings if they are getting poor as well. Lube the regulator and latches when you are inside the door.

 

[RawbDidIt]

I would focus more on the doors and the rear cab wall, might want to replace the window run channel and window belt moldings if they are getting poor as well. Lube the regulator and latches when you are inside the door.

You sir, are very thorough. I'm going to have to print this out before I start so I can glean all of the knowledge you and df2x4 have put in this thread.

Window linings appear to be in good condition, no cracks, no scratches in the tint, and no screaching when the window rolls down. I'll have a better idea when I get the trim off, but I think I'm good there. I'll also have to check the rear windows as well, but from what I remember (the truck is still in Nevada, won't have it Texas until next month) they were in near-new condition. The truck is in surprisingly good shape considering it's 20 years old. That said, I'm still planning on running all new speaker wires, and I'll probably do a big 3 upgrade as well. I highly doubt the stock grounds are going to be enough to handle all the power I'll be pushing, and I know the new alternator will need some extra copper to do it's job. I'm having a second battery installed before it gets here, and possibly a HO alternator as well, so I'm thinking I have all of the large bases covered... for now at least.

 

[michael hurd]

No real need for a second battery. Larger alternator means more ripple current, and I doubt that you will be pulling more than about 20 amperes continuously with what you have. If you have a concern about the age of the alternator you can go ahead and change it out, but I would not spend a pile on one. A stock replacement 105 or the installation of the factory optional larger alternator ( needs a different belt length ) will be adequate.

The money you would allocate to a second battery and alternator would be better spent in other areas, such as sound abatement products.

Factory cab ground is on the passenger side near the heater box on a vortec truck. This needs a substantial upgrade if you plan on grounding the amps to the sheetmetal of the cab.

 

[RawbDidIt]

The battery and alternator are at a steep discount. I also plan on running auxiliary lights at some point. I would feel much better with the extra power available. Also, I'm pretty sure the alternator is bad in it anyway, so I'm not throwing away a working alternator. If you'd like to weigh in on the symptoms to see if there's something else we should check (besides the obvious voltage readings with car off, and again with it running), I'll list those below.

Voltage reads low on the dash (around 12)
Low power, and seems to lurch when the pedal is pushed too far.

I'm having the fuel filter replaced, but our running theory is that the truck is running exclusively off of the battery, and the fuel pump isn't getting the voltage it needs to push enough fuel to match the air reaching the engine at full throttle. Truck can still accelerate to highway speeds (over 75 MPH), but it takes longer than I expected.

Air filter was just cleaned, very thoroughly (K&N high flow air filter). It helped with low end power, still lurching when trying to push past a certain point on the throttle. Symptoms seemed to worsen after driving for a few hours.

On a completely different side note, I'm also having the rods and mains replaced, and checking to see if we need to have the crank turned. There's a slight rod knock on start that goes away after warm up. One of the many benefits of having a retired dad with a fully-functioning shop is that I have the ability to make sure everything is in order before I receive the truck. The caveat to which is that anything that happens after can't be blamed on the condition in which I received the vehicle...

 

[michael hurd]

The voltage gauge in the dash can be made to read any value in it's range, the needle comes off and can be installed in a different location. Without diagnosis, you are grasping at straws with respect to the alternator serviceability.

Low power can be a myriad of symptoms, but the K&N air filter would be one thing I would replace with a paper air filter. Oil from the filter can and will coat the fine wires in the mass air flow sensor, and give false information on the air flow to the computer.

Poor engine grounds can also cause issues with driveability. A friend thought the spider needed replacement in his truck, turns out the ground was very poor at the battery. Cutting off the factory crimped on and over-molded connection revealed the problem.

The truck would start right up in the morning, but subsequent re-starts were poor, requiring more cranking, and smelled of raw fuel, as though the poppets were leaking down. Fixing the grounds up cured the issues.

 

[RawbDidIt]

The air filter isn't the issue. We didn't just blow it out, we scrubbed it out with soap and water until the water ran clean. It was filthy, and it took a while, probably around 30 minutes of solid scrubbing, rinsing, and repeating, but it came clean eventually. Like I mentioned before, it's at a fully functioning shop, the alternator will be tested before replacing, but I'm fairly certain it's a combination of old fuel and tank crap plugging up the fuel filter and low voltage, mostly the former, compounded by the latter. I'll see if he can check the grounds while he's testing the alternator. Did your friend ever find out what caused the fuel smell? Not enough spark?

Oh, forgot to mention a symptom, the starter lugs when turning the engine over. Before he replaced the battery, he jumped it and it didn't lug while jumping... Leave it to me to leave out the most damning piece of evidence against the alternator.

 

[df2x4]

You mention you're running a K&N filter...

I'd go up to the parts store and buy a can of MAF sensor cleaner, and clean your MAF extremely well. Could definitely be part of your issues. I ran a K&N FIPK on my red truck (well, still do, I just replaced the filter with an Amsoil) for a long time, and it fouled my MAF a few different times. One of which during the period of time where the filter was BRAND NEW and had the factory dose of oil on it. Michael wasn't just blowing smoke, K&N air filters are awful. I would absolutely stick to ACDelco paper filters if you're still running the factory intake.