Also whats the difference between a 'sealed' and 'vented' enclosure. I know the cosmetic differences. Whats the different sounds?

Which do you recommend for the G-coupe?

'04 G coupe TB Graph 5A (all options except NAV).
No Mods.....yet

"Hello Everybody...My name is Black and I am a G-oholic."

 

BB,
You won't have to do any cutting but you will probably have to drill new holes for teh speaker brackets. It's not that big a deal though.

I'm going to go with either a JL 10w6v2 or their 10w7. I haven't decided which. the w6v2 will run very well off of 250 watts RMS. The w7 would do OK on 250 watts but would do really well on 500.

Sealed v. ported: Sealed boxes usually have much better response and sound quality. The boxes are usually smaller so it will weigh less and take up less space. Ported boxes are usually a lot bigger, and will generally have a higher output with the same amount of power. They usually don't sound as accurate as a sealed box though. I would suggest a sealed box due to the size, weight, and better sound quality.

 

al503,

Seems as if many are benefiting from your experience and insight and keeping you busy, do you work for/own an audio shop? Just curious, you have been helpful.

I have a few new concerns (will they ever end?) about my crossover setup. I put the front MBQuarts at about 100, the rear BAPro around 60 (I think I want to raise this to 80-90 range and the subs to about 70-75) and the T420 has both a LP and a HP crossover, so I put the HP to the BAPro at around 500 thinking I would then only get midbass to the rears for fill. Does that seem true about the midbass?

The other issue is how different it sounds from song to song. I can tune it and it will sound great for some ludacris or jay-z (more low hitting music) and the next rap/hip hop song with the same characteristics will sound flat?!?!? Or I tune to Eiffel 65 or Def Leppard and it sounds awesome, but then next Def Lappard song or Sonique or Darude sounds poor?!?!? So I finnaly tune to the radio, a hip hop station and it sounds good for the song but then later songs go flat. It is odd that it will sound good for some songs and with no changes sound bad for the next ones. It was not like that before this weekend where it sounded really good for almost all music with really no adjustments - which are limited to the bass/treble and fade of the stock deck - needed only a +/- to the bass or treble when switching from rab to 80's music for example (the only change this weekend was adding the T420 to drive the rear BAPros which were previously driven off the stock amp).

So, to summarize and tie up this novelette, does my crossover idea seem valid or should I go full range on the rears and not from 80 to 400-500 and is my setup at fault for the vast differences in qualtiy from song to song, both within the same genre and crossing genres?

Thanks for your help, it has been a valuable resource yet again. Makes me think I should hire someone professional to come an tune my setup for good. Either that or just put me out of my misery and go back to stock .

Pics so far http://www.imagestation.com/album/?id=4290936425

 

I don't work/own an audio shop although I think it would be fun and the $ they get for installs are outrageous.

On to your questions:
I think 100 to your comps is fine. You'll get great response and they won't have to reproduce the frequencies better suited for a sub. I think that you should also set your BA's there or slightly lower (80-90 hz). By setting your BA's to 500, you will lose a lot of SPL in an important frequency range. Finish off with your subs around 5 to 10 hz lower than the lowest setting you have for the Quarts or the BA's.

Just like a car with very stiff springs would work well on a track v. mushy springs, you are going to have to find the best compromise for your listening needs. I think if you do something similar to what I listed above, you'll be able to get close to what your are looking for. Good luck and don't go back to stock for the love of all that is right and good :-).

 

Al, thanks to you and some others on this forum, I am now looking at upgrading the stock system (I don't think my wife wants to thank you, though). I was just visiting my local car audio shop, which has actually received some good press from national pubs. They told me that there was no way to add an amp to the stock system.

How are you connecting the subs?

'03.5 6MT, Brilliant Silver Sedan
clear corners, aluminum pedals, debadged, and soon to be <font color=green>GroundingGear™ Equipped</font color=green>

 

It's called a peripheral ven4. It's what a lot of G owners are using to connect the the factory headunit to the amps. If you do a seach for ven or ven4, here and on Freshalloy, you will find a ton of information. Sounds to me like some of that recognition may not be warranted.

 

al503,

I finished my tuning yesterday, it still needs some more with someone more knowledgeable and with a better ear, but it is way better than before. I started at your suggested levels and from there went to about 110 on the MB with the 300/2 gain at about 70% of max, the BAs I put around 90 and the subs at 80. Something I am just wondering is why have a 5-10Hz gap between the subs and the mids and highs? Would that not take out or eliminate those frequencies? I had thought a crossover where 10-15Hz was covered by both was good for good sound misture, but I do not know and I am just curious about that.

Pics so far http://www.imagestation.com/album/?id=4290936425

 

Good question. When you overlap crossovers points, the consensus is that you might get some cancellation between the speakers that are trying to reproduce the same frequencies. I don't think that it matters too much between the speakers inside your car but there might be a bigger effect between a sub and other speakers.

Depending on your crossover slope, 12, 18, or 24 db, you will still get those missing frequencies to some extent so in actuality, the sub will still produce frequencies higher than 80 hz (in your example) and your BA's will produce frequencies below 90. They just won't be nearly as loud because of the filter. Hope I've made sense.

 

What is a Ven 4? Do I need one for my project? How much this thing cost and where do I get it? I did a search and didnt come up with anything...

'04 G coupe TB Graph 5A (all options except NAV).
No Mods.....yet

"Hello Everybody...My name is Black and I am a G-oholic."

 

The ven4 is the Peripheral Ven 4. It is a line out converter that takes the headunit output and converts it to RCA or patchcord signals. I got mine at autosoundgear.com. It's about $50 shipped. You can use other LOC's such as PACs which I hear are good.

 

Al,

Did you get your G yet? I'm still curious about where the stock amp is located.

 

Yup. Got it yesterday morning. I've put in the clear corners, aluminum pedals and gave it a nice wash. Found a couple of bad scratches though. I've gotta put in the z-tube and upgrade some wiring tomorrow. I'll check for the location of the amp. From what I've read, it's somewhere on the drivers side of the trunk. I'll let you know.

 

Doc,
OK, put some new clearance and fog lights, upgraded some of the wiring and ... the bose amp is under a big plastic cover under the trunk mat on the drivers side. Before you try to pull the cover up, make sure that you unscrew a 10 mm screw on the right side first. You'll need a 6" extension to reach it past the spare.

 

Al,
First off, congrats on finally gettin your G. Second, thanks for the info. I'll check it out tomorrow. Are you planning on using that space for your amps?

 

There is a lot of room down there. I don't think I would be able to fit the 450/4 but the 500/1 will fit in there nicely. The only thing I worry about is that the JL's create a lot of heat. I would feel much more comfortable if I had the heatsink pointed up but we'll see. I also plan on getting xm or sirius so the tuner might take up some of the space there. I'll let you know.