I need some input from the experienced people here. I previously had a JL Audio Bandpass box with 2 x 12"s (CB212-W3) and a 923 Kenwood amp (200 Watts RMS and almost 10 years old) running in my Durango with the stock stereo. It sounded great! Fast forward to today...

I upgraded the amp to a JL Audio 500/1 (500 watts RMS) and a Pioneer DEH-P9400MP head unit (with all the appropriate adapters to work with the Bose system). I was all excited to crank it up as I just finished the install and it sounded awful. The bass was muddy and the back deck was rattling like a snake.

I played around with the settings on the amp and the stereo and got it to sound marginally better, but nothing like the smack in the back of the head bass I used to have in the old car.

Specifically, here are some questions:

1) Could it be the Bose sub making all the rattling? Can I just unplug it?
2) Does the trunk in the '03 Maxima trap that much sound? Would it help to remove the Bose sub and use the vent to get bass from my kicker to the passenger compartment?
3) My headlights were also dimming, is a cap really necessary for one amp?

Any input would be greatly appreciated. I can't imagine that with better equipment it would sound worse!

 

how are the 2 12" subs wired? how did u wire them up to the amp?
did u switch polarities on the speaker wire? they can sound muffled if you did.

 

The subs are wired mono to the amp via one input on the box. The polarity is correct.

 

Yeah, if you are not using it you should definately take out the stock Bose sub.

If your headlights are dimming with just that one amp something isn't wired up right.

 

A cap will help with the headlights dimming. It may not cure the problem though. A JL 500/1 will draw over 50 amps of current when pushed hard, so it will put a strain on a cars electrical system. When we use more than 1 JL amp, we almost always use a 1 farad cap.

The problem with the "lack of bass" is kinda hard to explain. In your Durango, you had alot more room for for the bass to travel...I mean a low bass(30hz or so) "wave" is very long, and the limited trunk area is hurting you. Try 2 things. First, make sure your box is facing towards the BACK of the car, not into the seats. Second, remove the Bose sub to allow the sub in the trunk to vent into the passenger compartment.

As far as the amp settings go, swith on the sub sonic filter. You want it set to around 25hz. You can also play with the phasing of the subs. The amp should have a phase swith, try reversing it. Good luck.

RichK

 

RichK thanks for the response! I agree in general with the box facing the back of the car, but since this is a bandpass the port is on the side (and the woofers are sealed with 1" thick plexiglass). If I flip it around the port will just be on the left rather than the right.

I'm going to rip out the bose sub tonight. Since I'm doing that, is there any reason to have the line level converter piece that is wired in to work with the Bose stereo? I read on the board that the door speakers are bose and will get fried by the power of an after market head unit. Is this true? Ideally I would like to just have the stereo connected directly to the speakers, but let me know if I would have to upgrade the speakers to be able to do this.

It sounds like I can have good sound in my Max Thanks for your help!

 

anything with ports need something to bounce off

my L7 box need 4-6 inches of space so the air bounces off the trunk

bandpass produce a lot of air...have u tried folding down your seats?

 

check your ground!!!

 

Let's start from the beginning. If you use the factory Bose head unit, and you want to replace the speakers, I would definitely buy an amp for the 4 speakers. The Bose amp is crap. You will also need to keep in the adapter to use the Bose head unit with the aftermarket amp. Bose head units have a special output in which DC offset is used.

Since you allready replaced the head unit, I would definitely do a speaker upgrade. They are definitely the "weak point". Then you can remove the Bose adapters, which, in even the best case, degrade sound quality.

I have used MB Quart speakers in Maximas with great results. The 5th gens take 6 1/2s all the way around. You could go with any 6 1/2s, though I would reccomend separates for the fronts. A great amp for the 4 speakers would be a JL 300/4. It has plenty of juice to drive any speaker you put in there. JL components aren't a bad choice either. I can only go into so much detail in what you could do. This could turn into a small book. Take it step by step. I will try to help in any way possible.

RichK

 

Rich, you kick butt!

I removed the Bose sub (if you could call it that )out of the deck tonight and like 90% of the problems were resolved - including the headlight dimming ! Apparently, all the distortion was coming from that. Also, I now have a nice vent for the bass to come in from the trunk. It was like night and day! There is still some rattle on the rear deck, but I guess I can get in there with some dynomat to resolve that.

Now that I was able to crank it up, I noticed that the factory speakers (well, bose speakers) sound like crap. I'm also thinking about upgrading to MB Quarts or JL Audio separates (most people say MBs are superior). However, money is a concern so I do have a question:

- How will these speakers sound amplified off of the head unit (22watts x 4 rms) until I can get the scratch for the JL 300/4?

I've also been reading a lot of posts and people seemed mixed on using the factory wiring...what's your opinion? I dread having to run cable to all the doors.

 

A single 500 watt amp of any classification should not strain the alt in the maxima (120 amps). Your lights should not be dimming. Check your power and ground wireing gauge and connections. Removing the bose sub would not solve this problem. It sounds like a loose wire because of the temporary nature.

There are plenty of good sounding speakers. Don't go with an expensive brand because of a recommendation. Choose one that sounds good to you. Then expect it to sound totally different in the car based on the quality of the install. Any speaker will sound better with 75 clean watts than with 22 distorted watts. I wouldn't bother upgrading the speakers untill you have the time and money to upgrade the amp. That's just me because I would blow great speakers with a cheap head unit. I expect the best sound possible, no less. There are also a lot of other 75 X 4 amps that will sound just as good as the JL for a lot less money.

 

If/when you upgrade your speakers, an amp isn't "needed". I mentioned one because of the amount of power you are using on your sub. I didn't say you "needed" a JL amp either. Use any good 4 channel amp you can afford. Alpine and Kenwood also make good sounding amps. If you use the head unit to power the new speakers, new wiring isn't that necessary. I have done it both ways with an amp. Without rerunning wires into the doors, and replacing the wiring. The difference is negligable. So I leave that decision to you.

I recomended the speakers I did from experience. Before becoming a Realtor, I was a shop manager at a VERY reputable shop on the main line in PA outside of Philly. I still do manage that shop, just fewer hours. I have only been dealing with car audio for 20 years though, so I am no expert. I have installed/sold countless brands of equipment, so I can speak from personal experience. There are less expensive brands out there, but I like to deal with reliable equipment. What good is it spending 100 bux less on an amp that may stop working in a year.

My last Maxima, an 89 SE 5spd, had our store demo system in it. There was over 18,000 bux in gear in that car. It sounded great. Don't get me wrong, I was able to closly replicate the sound of that system in other cars without spending that much. However, I wanted "bulletproof" equipment. Stuff that didn't need to be replaced every 4 years. I owned that car for 13 1/2 years and NEVER had a problem or blew a speaker.

One more thing, the JL amp will dim the lights. If you do simple additon on what kind of amperage you car needs to run. Headlights, parking lights, fan/AC, can draw over 40 amps. Now you have an amp that is pumping out bass and shaking houses that is drawing another 40-50 amps. When the car is at speed, no problem. But with the car IDLING, the alternator isn't producing anywhere near the 140 amps it is rated at. It is closer to 70. I have babbled enough. In any case, take my advice for what it is. Advice. As always, do what YOU feel is right. Everyone has different ears so all people don't like the same thing. My advice is to listen to every possible speaker choice BEFORE buying them. Good luck.

RichK

 

Trust me, I'm not the type to take everything as gospel but I do appriciate your advice. I've had some experiance with stereo systems before...just not the Maxima. If I get an amp it will definately be the JL Audio. I've had their subs for years and am very happy with my new amp. I agree as well that it pays in the long run to spend a couple extra bucks up front and get the quality.

Having said that, with the JLs and the MBs speakers..can they be run without an amp and still sound good? Or, am I better off getting an ok set of speakers (better than the bose) that are optimized for the low power head unit until I take the plunge and get the amp and speakers?

I have no problem spending the money, but my priorities have changed from when I was younger. I just have to make sure all the bills are paid first. My mortgage company doesn't like to wait

 

Perhaps it was a combo with me playing with the gain on the amp? Oh well, it seems to have stopped the dimming.

I agree with your feeling about not going with expensive speakers because they were recommended, but as you can see from my above post I was already thinking along those lines. However, I would love to hear any suggestions you have for low price - low power speakers that I could use in the mean time just to get things sounding better.

I am a lot more lax with the sound of my car system...I save the perfection for my home theater!

 

Well, I live in a townhouse so my good system is in the car. Don't get me wrong, I probably have a few grand in my old fashioned home system. I also agree it is better to get quality equipment if you will be keeping it more than a few years. Most young kids only keep equipment and cars for at most 2 years.

I've also used amps with 70 amps or more current draw in a little VW with no light dimming. Not enough can be said for good wiring. By good I mean choosing a sufficient gauge and getting good connections. The Maxima alt puts out more current at idle than an old VW at highway speed.

I think if you currently have the bose system and you upgrade the speakers then you will need to run new speaker wires. But I have never owned a car with bose stereo. Nor do I plan to own one.

I won't recommend a speaker because they all sound different. And your impression of what sounds good is different from every other person on the planet. And buying a low price speaker now would sacrifice that much money that you could otherwise use in a month to get better speakers. A speaker can sound good with the amp built into the headunit. But you already indicated that you crank it enough to cause the lights to dim. At that point the headunit amp is most likely well into clipping and signigicant distortion. That is where you will be likely to damage speakers. It may be difficult to tell the amp distortion from speaker distortion and easier to push them beyond their mechanical limits.

I won't recomend an amp because they all sound the same. Although the JL 4 channel does have less potential SQ at low volume because of the seperate power supplies. I don't think most people would be able to hear when it switches between low power and high power. It makes the amp more efficient.

 

Amp or no amp, get the best speakers you can afford. They will sound fine without the amp, and much better with it. No sense in wasting money on speakers you will take out after you get the amp. Plus, I hate taking cars apart over and over. You are just asking for rattles.

RichK

 

Good point. I'm gonna check out the JLs and MBs this weekend!

 

Just remember, if you think they will sound good it will take a really bad set-up to make them sound bad.