Any Car Audio Gurus Out There?

[rawfuls]

Just finished the wiring portion, sub is coming tomorrow, I'm pumped!

The hardest part IMO was crimping the ring terminals on, since I don't have a proper crimper, I had to use a combination of pliers, vice grips, a flathead and a hammer..
Since I can't find our blowtorch, I ended up opting for a BBQ lighter and some solder to finish the ends.. I'm not sure it was too effective, but it seems to have melted in somewhat.

I couldn't find the firewall grommet, but I did find a metal plate that was bolted onto the firewall that looked like a grommet was supposed to be there... so I drilled out the middle, filed it (somewhat), taped the inside with etape, and then found the KnuKonceptz grommet and ran the wire right through there.
I feel much safer than before.

I couldn't find the black tubing that was supposed to run along the firewall, so I ziptied it to a couple of mounts, and over a plastic-looking-thing.. hopefully it'll stay and stay cool.
This is where I opted to put the wire loom (in the engine bay) since it'd at least give me a smell if something starts melting.... also to prevent insulation from burning away and shorting something out.

Ran it under the sill plates, carpet, and then under the rear seats to come out like a snake directly into the cargo area, looks pretty good, but I need to trim the wires as the power line is a tad long. I plan on putting the fuse on top of the sub (I think it'd look the best), or on the back with sticky tape...
Ran the ground to the fuel pump mount under the passenger rear seats.

The head unit was sooo much easier than I expected, I actually only needed a screwdriver to press the springloaded tabs inward while I worked the head unit out..
Once out, I couldn't find the antenna, until I took out a trusty multimeter and tested the wires until I found the switched ground which I soldered directly into.
Ran the RCAs and Remote on the passenger side and into the back.

All the wires are ready for action tomorrow when the sub comes in, super pumped!

Thanks for all the help, I'll let you know how it goes!

[bdebde]

Best place for the fuse is at the battery... If the wire ever gets worn through or cut, the fuse will blow.

[rawfuls]

Yeah... I just remembered that, it's going to change first thing tomorrow morning!

[_paralyzed_]

awesome, I hope it all works out for you! I love car audio.

I'm gathering components for the next system in my van, I just need the front component speakers.

It will consist of an alpine cd player, 2 sets of mb quart component speakers in the front doors, 2 sets of infinity coaxials for rear fill, 4 jl audio 12w6 12" subs in 3 cubic foot ported enclosures (12 cubic feet of sub box!), a 1000 watt crossfire sub amp ran at .75 ohms for over 1200 watts, and a 4 channel crossfire amp for all the mids and highs.

I will be heard for miles! I have always built systems for sound quality, this last system in my van will be all about loud, a literal rolling boom box.

[rawfuls]

Got the sub in today, will be hooking it up in about an hour.

How do I finetune it?

Here's what you do- You set the HPF on your front speakers. Then, before the sub is hooked up, turn the radio up until the front speakers start to distort. Let's say you turned it up to "30" before you heard distortion. You now know the limit, 30 is too high, don't turn your stereo up past 28. The fronts won't sound the greatest with no bass playing, but be patient, the bass is on the way. Now play some music at 28 (your safe level) and start turning up the level on the subwoofer. Continue to turn up the sub until you hear distortion, then back off a little. Doing this should prevent anything bad from happening to your current components.

Once the sub is connected and tuned to level volume, should I turn HPF back on the front speakers?
Or can I leave them off and have the bass do all the work?
Which Hz rating would work the best"?

[rawfuls]

Set the HPF to 100Hz, and cranked level to about 30%, Phase midway (what does phase do..) and same with Frequency (and what does this do? :p)

Thing sounds awesome!
Much better than before, and now I may have gotten the car audio bug, because I'm thinking about front speakers!

Whenever a nice boomy song comes on, the sub definitely overdoes the speakers, so it's kind of hard to hear, I suspect just turning the level down will cure that..

Other than that, it's awesome!

During installation, though, need to clean the wiring up, bad!
Going to need to isolate each connection just for my peace of mind the way I drive.
Also ,when I was finishing the install and pushing everything in the back, I crushed my seat down onto the RCA connector, and snapped one of them right into the socket.
The center pin is now stuck in the sub, and the other channel is a little crooked, but works.

I'm guessing I'll need to find a way to pull the pin out, and put on new RCAs (definitely).
Going to see if I can find some 90degree ones..

[BrianG]

Subwoofer phase helps to align when the sounds reach your ear to compensate for mismatched speaker placement between the sub and main speakers and usually affects frequencies near the HPF and LPF point. Without a real-time analyzer, it can be difficult to set properly. I would just keep it at 0 unless you can hear the difference.

[_paralyzed_]

I'm glad you got it going and that you like the sound! I've been busy with my son so I haven't been online as much.

Be careful with the car audio bug, it can get expensive!

[rawfuls]

Oh no....

So whenever we turn up the volume a little over 40ish, the speakers start to distort pretty nasty, but the sub keeps up just fine (and rocks, btw!).

I'm now looking into grabbing some new speakers, but was curious what you recommended Harold?
I know you're quite the guru so far..
Looking for something priced well, maybe budgeting myself to about $50 for 4?

[BrianG]

The "speakers" distorting could be one of two things; the amp is clipping sending a distorted signal to the speakers or the main speakers are getting too much bass signal and are moving beyond their mechanical limits. Either turn down the gain a little and/or turn the crossover so they get less bass (120-140Hz @ 12db/oct or 100-120Hz @ 24db/oct should be good).

[rawfuls]

The higher the Hz @ HPF, the less bass the speakers get right?
What does LPF do?

[bdebde]

HPF (High Pass Filter): allows only frequencies above cut off point to pass through

LPF (Low Pass Filter): allows only frequencies below cut off point to pass through

[BrianG]

Yeah, and the Ndb/oct is the slope of the cutoff.

12db/oct in a HPF means that for every halving of the frequency, the output will drop by 12db.

12db/oct in a LPF means that for every doubling of the frequency, the output will drop by 12db.


So, even though you have a HPF set up, the speakers are still getting some low frequencies and could be overworked trying to produce bass frequencies. A steeper slope (like 24db/oct) helps. 6db/oct (which is what you get using a capacitor on a speaker) is unsuitable IMO - the slope is not very steep.

[rawfuls]

Originally Posted by BrianG

Yeah, and the Ndb/oct is the slope of the cutoff.

12db/oct in a HPF means that for every halving of the frequency, the output will drop by 12db.

12db/oct in a LPF means that for every doubling of the frequency, the output will drop by 12db.


So, even though you have a HPF set up, the speakers are still getting some low frequencies and could be overworked trying to produce bass frequencies. A steeper slope (like 24db/oct) helps. 6db/oct (which is what you get using a capacitor on a speaker) is unsuitable IMO - the slope is not very steep.

I believe my headunit maxes out at 180Hz (so 18db/oct)?
I'll put that up and test it out then.

[BrianG]

That will definitely help the main speakers from trying to reproduce any bass, but don't go too high because if there is too much of a gap between the main speakers and the sub, you'll notice a gap in midbass sound. And if you increase the LPF filter for the sub, the higher frequencies produced by the sub will pull the stereo imaging towards the sub (mids/highs are directional while bass frequencies are more omni-directional).

I would go around 140Hz on the main speakers and around 120Hz on the sub, even at 18db/oct.

EDIT: I just re-read your last post. Just because the HPF tops off at 180Hz doesn't necessarily mean it's 18db/oct. You should be able to find what the actual slope is for your device via a google search or the device's docs. Common values for "active" crossover slopes are 12db/oct (so-so), 18db/oct (good), and 24db/oct (best). Slopes higher than that are good too, but aren't common. "Active" crossovers are ones that use DSP or other active (powered) circuits to handle the crossover, and are done before the signal gets to the amp. "Passive" crossovers just use capacitors and inductors (and sometimes resistors too) between the amp and speakers, and do introduce insertion losses and can also reverse the phase, so are more difficult to build correctly.