twin_snails

iTrader: (2)

This is a post that I actually dread having to write because there's not a lot of clear information out there for car audio noobs. I know I may get suggestions to research this but it seems that the more I research it, the murkier it gets. I am only knowledgable on car audio to essentially replace like for like so I'm hoping to solicit some solid advice from the great community we have here. Unfortunately, this is just one area where my knowledge is pretty thin.

I've been doing some research and there seems to be a lot of different answers on what speaker sizes are in the rear doors of a G37 sedan with NAV and the Studio on Wheels.

I'm contemplating replacing my speakers in my car because I have the ability to buy Infinity and JBL speakers and amps at a huge discount.

1) I'm considering replacing the front tweeters, front 10" woofers with 6 1/2" 3-way components.

2) I'm not sure what speakers are in the rear doors so I don't know if 6 1/2" will fit there.

3) What type of amp would I need for the front setup? As in how much power and how many channels?

4) I will probably do two Infinity 10" Kappa subs with their own amp. I may do custom separate enclosures to mold into the sides of the trunk.

5) If anyone has any ideas for distilling the 11 speakers from the SOW down to a solid aftermarket setup of a reduced amount of speakers, I am all ears. I don't want to go ultra custom...I'm looking to retain the stock look but upgrading the speakers and subs.

6) The subs will probably 400 watts to each one and possibly a 940 watt (peak) x 4 channels (assuming that will power whatever I do with the fronts).

7) Will I need caps? The last system I had in a car was a long time ago and it had a 1 farad cap and my headlights dimmed if I turned it up any amount.

8) Will I need an upgraded alternator? I've found aftermarket ones of about 270 - 330 amps.

I should also note that I'm absolutely not qualified to install something like this and am nervous about taking my car to cartoys or something and have them botch the install.

If people are willing to chime in on this thread to report the various speaker sizes for the base stereo and the SOW, I will compile all the information together to put into a sticky so we can have a central repository for this information.

I want to thank anyone in advance that is willing to chime in on this thread because it's a real grind to me.

Black Betty

iTrader: (60)

I can help with a little info, but am far from an expert. My last audio install was some time ago. Planning it all out before buying and installing things is very important so you are heading in the right direction.

1) A great idea
2) I don't remember. But screw rear speakers, music should only come form in front of you (except low bass).
3) Amp depends on what components you use. I'd suggest a 4 channel amp and running a discrete channel to each driver. Power sufficient for whatever speakers you are using.
4) OK. But unless you're trying to be one of those jackasses who thinks the world should hear whatever horrible bass heavy garbage they are listening to (please don't be like my neighbor), an enclosure with a single sub and amp will be more than sufficient.
5) Components in the front soundstage. No rear speakers. Single trunk mounted sub. Simple.
6) 1 sub capable of handling 200-400 watts and a single quality mono sub amp will amaze you with its output if done correctly.
7) NO!
8) Doubtful. It depends entirely on how much amplifier wattage you have and how much you push them. For a normal sound system, no.

Another huge key is finding the right installer. Generally avoid the box electronics retailer installations unless you want a 20 year old kid who rode the short bus until he dropped out of the 10th grade last year cutting into your car's wires. Find a smaller volume place with an experienced expert and pay him a lot more than some speaker jockey. Lurk on audio forums and see who is highly recommended. Check out his former installs. Get references. Listen to the advice he gives you.

Absinthe

At the risk of echoing much of what BB has already stated, here goes.

1. Probably get the most sound quality bang for your buck here. The door speakers provide most of the soundstage on the G. I've heard some nice setups that employ added tweeters/mids to the A pillars but that involves making your own very custom enclosure and mating it to the existing pillar. One thing to consider if you go with a multiple speaker setup in your doors, either you do a multi-amp setup with frequency division between the drivers or you do a passive crossover setup in the doors. Each has its benefits and its problems. Figure that bit out before you dig in.

2. Can't help you much here since I have a coupe. However, much of what BB says rings true, you get almost no soundstage from the lower mounted rear speakers. I do get a nice bit from the speakers mounted in the rear package shelf but it takes some processing power to bring those out. Once you get through with the tuning and balancing nightmare, the sound is a bit fuller and more powerful than omitting them.

3. Again, this depends on how you want to set up the drivers. If you want a discrete channel for each speaker, you will obviously need a 4 channel amp and a processor with a graphic equalizer and electronic filtering to drive each amp with the proper frequency range. If you want to design and build your own passive crossover, you can do it with a single amp. As much as I like multi-amp setups, I went with the passive crossover because I like the challenge. Power requirements depend on what kind of volume your looking at. Most of your power will drive the 10" and your not going to get a whole lot of bump from an undamped driver in the door. I've got a single T400-2 RF amp running my front doors. It gives me a nice balance but the mids (on any song from Boston) could use a bit more punch. I'm not sure more power is the answer here but perhaps a better midrange driver.

4. Realistically for most people, one sub is good. If your going for sheer low distortion impact, you should plan on two subs; although I admit to keep the system balanced the gain on the subs will be turned down otherwise the bass would overpower the rest of the system. Definitely put them in custom fiberglass enclosures unless you like donating your trunk to speakers and little else

5. This is so dependent on what you like to listen to and how you like to listen to it that simply copying one guys setup will likely lead to dissatisfaction. You don't need to replace all the drivers. As stated previously, not all 11 speakers contribute significantly to the soundstage.

6. Peak power ratings mean little when it comes to sound quality or impact. RMS is the industry standard for rating amps and drivers. You have a small car with a relatively small trunk, pick subs that work well in the space you have (or are willing to dedicate to enclosures) and pick an amp that is reasonable for the setup. IMHO much over 400-500 watts for the subs is overkill unless you want to be heard in the next county. Remember, the harder you drive the subs, the more bracing your sub enclosures will need, the more sound deadener you will need in the car and the most time your going to spend chasing down rattles; not to mention how much weight your going to add to the vehicle.

7. Most likely not. If you size your power wire properly you should not starve the amps A simple test is to monitor the DC voltage at the power distribution block in the trunk while driving the system hard. I've found that most problems with headlights dimming or other issues are caused by running too small a power feed line from the battery or crappy grounding in the car

8. At first I was undecided on this bit. I've been running three RF amps (1,300 watts RMS total) off the stock alternator for almost two years with no issues; so at this point in time Id have to say the stock alternator is fine.

I'm with BB on the install details. Steer clear of Best Buy, Cartoys, Circuit City and the like. Seek out a local installer who will discuss your wants and budget. Ask for references and go listen to what he has done. Most good installers have good word of mouth references but bring your wallet. Good install labor isn't cheap.

twin_snails

iTrader: (2)

First, I just have to say that you guys are awesome. This is one of those areas that's very subjective to individual tastes and listening preferences and types of music.

I know that car audio is a lot different than it used to be and exponentially more complicated because of all the systems that are tied into the factory head unit (NAV, bluetooth).

As far as my listening preference, I don't listen to a lot of rap. Primarily rock, country, some top 40. I really like clear definition and separation of channels and instruments, very crisp sound imaging and staging. With that being said, I know enough to know that it will absolutely necessitate a DSP to get the sound I'm looking for.

On DSP's I'm looking at either the JBL MS-8 or the Audison Bit One. I would prefer to go with the JBL because I can get it for a steal. On the drivers, I'll probably go with Infinity and if I buy new amps, JBL.

There are times when I like to turn up the volume and feel a tsunami wall of big sound. A wall of guitar sound in my face and bass that you can feel in the center of the chest. But that's not all the time. I am definitely not one of those annoying neighbor types. I listen at a moderate volume and always turn music way down when I'm in my neighborhood. I'm of the opinion that you shouldn't be broadcasting that you have a nice audio setup.

On my old setup (which I still have), I ran it off of two PrecisionPower amps. The sub amp was sending 400W to each sub and I had an 80 x 4 driving everything else up front, including the rear 6x9's. I had 6x9 3-ways in the rear deck with 6 1/2's and 1" tweeters in the dash. I have no idea how it was wired. That setup sounded great but it was over 10 years ago that I had it. My ear has evolved considerably since then so I think my requirements would be even more demanding now. The box for the subs was heavy but they sounded pretty amazing.

I believe the coupes have 6x9's in the rear deck but I don't think that's the case for the sedan. I'd like to have two of those without having to cut the rear deck.

I talked to my brother last night and he's got a guy that he knows that's very good and works for a small shop.

I knew to stay clear of car toys and placed like that because my boss has taken two vehicles there and they buggered both installs.

I'm definitely going to talk to my brother's guy before I buy stuff and see what he recommends so I can get the right components. Hopefully he's done some G's before. I'll see what he recommends and I'll report back here with what I wind up with.

twin_snails

iTrader: (2)

Thanks for all your input Absinthe! I've learned a lot from the input you guys have given but also realize just how much I have to learn.

1) I definitely don't want to go with additional pods of speakers on my A-pillars. That's a bit more involved than I want to go. I believe there are tweeters in the dash though. Is there a 3 1/2" in the front doors in addition to the shallow-mount 10's?

2) Great to know about the rear door speakers not providing much in the way of sound staging. I don't know if the sedan will accommodate 6x9's without cutting up the parcel shelf.

3) I apologize for the completely noob question here but can you run more than 4 speakers on a 4-channel amplifier? Say if I wanted to run 6 or 8? Would it basically be 2 speakers per channel? I will probably run two amps. One mono for the sub and one 4-channel amp for the front speakers.

4) I may forego two 10" subs in favor of one 12". I remember how heavy my old sub box was. It sounded amazing but I don't necessarily want to take up all that space.

5) Good to know but I'm fortunately in a position to buy at an amazing discount so I could probably do some pretty amazing stuff that I wouldn't otherwise be able to.

6) When you reference 400-500 watts for the subs is that combined or per driver? I will definitely make use of dynamat or whatever competitor is comparable.

7) That's good to know. I think on the last install they ran 4 gauge from the battery back to the distribution block. I guess that wasn't sufficient. I've heard that caps are not necessary but provide a reserve capacity to supply power when the subs are hitting hard. I wasn't aware that it was a matter of current handling ability of the wire. People have always said if you're lights are dimming, you either need a higher capacity alternator or a second battery in the trunk, which I'd prefer not to do.

8) That's reassuring to know. I believe our amplifier supplies 130 amps of current. I could be wrong but it's good to know that you ran that much wattage without incident.

Thank you again for all of your advice Absinthe. It definitely gives me some direction.

sp408

iTrader: (1)

If you're looking for some good subs at a great price. There is a guy on the private listing pages that is selling two JL W6V2s for $200 each. With a custom made sub box that fits perfectly into our cars.
Also, if you use a 3/4 thick mdf speaker mount for the front, make sure the speaker is no deeper than 2.75 inches. You may also want to have your door dynamated and with some other CCF material also. SecondSkin is a brand I'm pretty happy with. I've replaced all the speakers myself in my Coupe. So I understand the ****ty time your buddy in the shop is going to have.
If you plan on cranking the volume in your doors, I would recommend making sure your guy wraps some of the door wires in a spongy material. Also the window motors. Put some material behind those. The CCF works pretty well. I had to keep taking off my door panels, because high volumes cause the cables to jumble around.
If you're looking into a Sound processor and have the budget, I would go with the Alpine unit. It's a $1000 when you buy the head unit too(which you have to buy)
In some reviews I skimmed through it outperformed the audison. Up to you though. It only took me about an hour to learn the software enough to be proficient.

Absinthe

I can't speak from experience on the sedan but on the coup there is a 1"soft dome tweeter in the door sail, a 3.5" paper cone mid in the upper door panel and the 10" pancake woofer. Id expect the sedan to be similar. IMHO its the 3.5" mid that is the true slacker. The cone breaks up long before you can get any volume out of it.

As far as running additional speakers off an amp, the answer is a definite maybe. If the amp is bridgeable, you can hook up the left and right channels as you normally would and then hook up a sub across the positive and negative terminals of both channels. You can also employ a passive crossover network to accommodate the frequency bands of each driver as well as the impedance dips. The key is to never let the amp see a prolonged impedance less than the rated minimum impedance of the amp. Most quality amps are good down to 2 Ohm; a few are stable down to 1 Ohm. The biggest problem with multiple speakers on a single amplifier is frequency control. Passive crossovers restrict power as they filter some of the amps output; they are also affected by the impedance fluctuations of the driver. A Zoebel network will minimize those effects, but unless the crossover is designed properly, there will be audio artifacts. The active crossover offers more control but at the expense of size, weight and cost. Your installer can help a lot with figuring out the best driver layout and amp configurations.

Going with a single 12" sub in favor of two 10" also has its pros and cons. In general a 12" driver will have a resonant frequency lower than a 10" sub. However, by using bass extension in the enclosure construction and in the crossover design, this can be minimized. A single 12" driver will theoretically move more air with less cone excursion; however this usually does not hold true in practical applications. A lot depends on the design and construction of the driver you've chosen. The best way to test out theory versus reality is to build 1 cu foot test boxes and put a 12" in one box and a 10" in a second box and give them an audition. That's really about the only way I know of to really evaluate the smoothness and sound quality a sub will have. Some installers will have this capability.

I'm running my two subs in series. There dual voice coil 2 ohm subs which net me 500W into a single channel. Everyone has their own favorite brand of sound deadening material; but for what its worth I've had extremely good results with the Second Skin line of products. They offer many products to help you achieve what you want. I highly recommend the luxury liner

You are correct, caps are installed near the amplifiers to assist with their transient response. When a sudden burst of bass hits, the instantaneous current draw can be enormous and can overpowers the battery's ability to supply current and the lead wires ability to carry it. The best defense against this is a good quality power lead wire. After doing a few dozen personal installs back in the 80's using 4 and 8 gauge leads, I gave in and just bumped up to 1/0. The wire is a little more challenging to work with but in the end it solved a lot of chronic problems I was having at the time. No more dimming headlights and it even helped with some noise problems I was having. Now I don't even question it. Where I do depart a little from the norm is in my selection of wire. I use welding cable instead of the more popular power wire retailers. The strand count and the current handling capacity is the same; but with a much lower price. The trade off is the welding cable is harder to work with and typically only comes in black, white, orange and red.

Good luck with your build, ask tons of questions before you embark and youll be happier with the results. Please share with the rest of us. Im always looking for a good idea I can shamlessly steal

Absinthe

+1 on the door notes. I took out the window mechanism so I could damplify the door skins more completely than just reaching through the woofer hole.

2012G37X93

Sorry to bump an old post but just wanted to let anyone know who is replacing 2012 G37 Sedan without Bose system that you have 6.5" Speakers in your front and rear doors with a tweeter in the front. That is it! 6 speakers and they are craaaap. Looked at one after taking off the door panel and they are cheap paper light as a feather junk.
Couldnt find any sizes anywhere online so just wanted to let people know!