Audio Build Log: The Gnome's 2017 Silverado

[ProjectTwin]

awesome work. it makes my best attempts at a clean wiring install look hack

Looking at your pod mounting - looks like the EZ-lock work for you and no reason to change, but curious if you ever looked at rivnuts for that use? may or may not be an easier or more secure installation, but i've never worked with the EZ-locks

I've used rivnuts on metal. Not plastic.

I used EZ-Loks because I needed threads in the pods - not the pillar.

 

[mobil1syn]

Spax screws were used to mount the subs.

SPAX screws are legit, too bad no one local sells them anymore.

 

[Snowbird13]

SPAX screws are legit, too bad no one local sells them anymore.

Don't they sell them at homo depot?

 

[Ted_Kaczynski]

Fuck rivnuts, I'd choose anything over those pieces of shit.

 

[Ted_Kaczynski]

I'd expect to pay more than $1,500 for that enclosure finished with hardware.

 

[Alpine4x4]

In addition to projecttwin’s reasoning, I think soldering wires that are in the box with the speakers would be one of those cases where the vibrations would lead to a failure. We’ve all heard not to solder automotive shit because vibrations will cause it to break and fail, and although I’ve never had that happen personally, I can definitely see it happening and I honk inside a subwoofer box would be the perfect place for it to occur

And wire nuts are better at resisting vibration? If you're worried about vibration then use butt connectors, fuck wire nuts altogether.

 

[Arps]

meh, kinda looks like he knows what he is doing to me

 

[bigun]

Why not just nix the wire nuts and solder the connection or use a butt connector? I personally hate wire nuts haha.
.

I was going to ask the same thing, then thought this cat is a professional at his trade like I am in mine, so he knows what works and what doesn't

 

[DWT]

And wire nuts are better at resisting vibration? If you're worried about vibration then use butt connectors, fuck wire nuts altogether.

Wire nutted and taped up. They aren't going anywhere.

 

[Alpine4x4]

I was going to ask the same thing, then thought this cat is a professional at his trade like I am in mine, so he knows what works and what doesn't

So is my side business partner who does this shit for a living as well, wire nuts are for solid core and not stranded wire, they dont belong in car audio.

Wire nutted and taped up. They aren't going anywhere.

I know that, just like soldered and taped up wouldnt either, so the vibration bullshit is out the window, it was a stupid point to even bring up.


Regardless, it works for him, whatever, back to the fabbing and build.

 

[ProjectTwin]

And wire nuts are better at resisting vibration? If you're worried about vibration then use butt connectors, fuck wire nuts altogether.

DD Audio sends them. SPL guys use them. Everyone in here bitching about using them.

You know who isn't bitching about them? People with cars I've built.

 

[ProjectTwin]

Tweeter pods got final sanding, primer, texture coat, and color. Bolted them in with EZ-Loks and machine screws.

These are shaped differently left to right because I aimed them at the driver rather than the center point of the car.

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Tuning gear consists of SysTune Pro, a Tascam 16x08, and six Behringer microphones.

The combination of six mics, the Tascam, and SysTune I can get real-time average at the listening position. If I were to measure with a single mic I'd get a response, but if I move that mic 2" in any direction, that measurement would change. The array of six mics gives me an average of all mics (if I chose all of them in the software), or I can get a measurement from a single mic if I chose to do so in the software.

 

[bigun]

WOW!

 

[bdkw1]

These are shaped differently left to right because I aimed them at the driver rather than the center point of the car.

Yeah, fuck the passengers LOL.

Looking good. To bad those 8's are so deep, I'm looking for some 8's for my Samurai, not enough space.....

 

[Hippie666]

I was going to ask the same thing, then thought this cat is a professional at his trade like I am in mine, so he knows what works and what doesn't

PT is not a professional, He is a fucking artist


edit for fat fingers

 

[Blugreenformula]

PT, you might have covered this already. On the pillar work, what do you do with the factory texture that pillars have? Do you prime and sand the whole thing to eliminate the texture?

 

[bigun]

PT is not a professional, He is a fucking artist


edit for fat fingers

I stand corrected

 

[Aisin]

PT, you might have covered this already. On the pillar work, what do you do with the factory texture that pillars have? Do you prime and sand the whole thing to eliminate the texture?

He probably uses SEM texture coating.

 

[TrikeKid]

Pure art! You inspired me to get back around to the a-pillars I was doing for my truck, been driving around all summer with my shit half finished.

 

[ProjectTwin]

Yeah, fuck the passengers LOL.

Looking good. To bad those 8's are so deep, I'm looking for some 8's for my Samurai, not enough space.....

That's funny.

Andy from Audiofrog was giving a class at KnowledgeFest. It was about tuning.

The entire class went through steps to tune for the driver's seat. The reason for this is that DSPs (Processors) will allow you to adjust crossover, output levels, EQ, and time delay for each channel. A graphic popped up that showed where a proper "stage" in the car is placed and where center stage should appear to be - out over the hood near the center.

There was also a graphic that showed improper placement that some folks think is right where center is directly in front of the driver. This results in a compressed left/left of center/center stage and a very wide center/right of center/right.

So Andy is going through the class and talking about how great the car should image for the driver.

Someone in the class asked "What about the passenger seat?"

Larry Fredrick (was with Electtromedia, Audison/Hertz at the time) said "Fuck the passengers! They didn't pay for it."

We laughed, but that's the reality for a LARGE portion of cars that have been built like this. They're optimized for one seat - the driver's seat.

It doesn't have to be "fuck the passengers", though. The processor that is in the truck, the Alpine H-800 (which has to have the RUX-C800 to function) will take a 2-channel stereo signal and upmix it to a 5.1 signal like Dolby PL II. With left, center, right, and rear speakers and proper up-mixing and processing, you can get a car to image fairly well for both driver and passenger.

A lot of the guys that compete say SQ (Sound Quality) is hard. They're referring to single seat judging.

SQ2 is two seat judging. It makes single seat look easy. Getting a car to properly stage and image from both seats (a judge in each front seat scoring at the same time) is infinitely more difficult.

The Camaro I built got 2nd at World finals in SQ2 and I pulled a championship win with the Chevellle in SQ2+, which is a separate class from SQ2 that allows stuff like horn-loaded compression drivers. That Camaro also competed in SQ, RTA, Install, and two SPL events.

What we didn't tell anyone is that we ran two processors in that car piggy-backed on one another.

The Alpine H-800 had two tunes loaded into it. Preset 1 was simply a stereo pass-through that sent signal from the head unit into the Helix DSP PRO MKII processor.

With the Alpine set to preset 1 we could run all of the single seat events (SQ, RTA, SPL) by selecting the tune for each event in the Helix.

When it was time to compete in 2-seat SQ we'd switch the Alpine to Preset 2. That preset gave use Dolby PL II up-mixing. At that point we were running 5.1 into the Helix. The Alpine was used for up-mixing to 5.1 and we did everything else (crossover, EQ, time alignment, phase adjustment) in the Helix.

This car was in MECA's 2nd lowest class of competition (Street) and punched way above it's class level.


Anyway, those tweeter pods that are aimed towards the driver instead of say...at the center between the headrests...don't really matter. Time delay and individual speaker output level matters more.

For the driver's seat you'll always have the left side driver's with reduced output levels when compared to the right. That's because with them at the same output level even if you've already entered time delay the fact that the driver's side speakers are closer and will appear to be louder than the more distant passenger side drivers. A mono pink noise signal should appear to be in the center of the car. Without reducing output levels for the driver's side that mono pink noise will be over the steering wheel. So you HAVE to reduce the driver's side drivers.

After doing that when you sit in the passenger seat you're in the "bad" seat. Time delay is optimized for the driver and the driver side has been reduced in output level. So...from the passenger seat what you hear is mainly the right side speakers.

At that point it doesn't matter how they're aimed. Output levels and time delay have already ruined that seat because, well...fuck the passengers.

 

[ProjectTwin]

PT, you might have covered this already. On the pillar work, what do you do with the factory texture that pillars have? Do you prime and sand the whole thing to eliminate the texture?

I did nothing to the A-pillars other than pop five holes in each of them to mount the tweeter pods and run speaker cable. The grab handle on the passenger side pillar kept me from modifying the entire pillar. It didn't make sense to re-work the entire pillar to add tweets. So...pods.

What I did for the pods was prime them (mostly to see them in one color and fill/sand/fill/sand to fix high/low spots. I use SEM's high build primer for that.

Then I shot the pods with texture coat. You can use sandpaper to knock down the texture and make it smoother. I typically do with a fine sandpaper. Just lightly go over it. Hell, a 3M pad works.

After texture is cured I shoot it with SEM color coat in whatever flavor it needs to be.

 

[ProjectTwin]

Pure art! You inspired me to get back around to the a-pillars I was doing for my truck, been driving around all summer with my shit half finished.

You could beat the shit out of someone with those tweeter pods.

They're blocks of reinforced fiberglass. I was walking outside with one, dropped the damned thing on the asphalt, and it shrugged it off.

 

[TrikeKid]

You could beat the shit out of someone with those tweeter pods.

They're blocks of reinforced fiberglass. I was walking outside with one, dropped the damned thing on the asphalt, and it shrugged it off.

Mine have been bare glass for 3-4 months. I fucked up the aiming on the first one but I was just happy to not have my speakers sitting in towels on my dash so I let it be. I also built them without any plan on how to finish them out since it's a Ford with the stupid fake leather grain in the plastic.