Muddy bass in sedan... can it be improved?

[CaptNKILL 10+ year member]

Hi guys. I put together my first system about 2 months ago, and I was extremely happy with it until I heard something better (isn't that how it goes?).

I have a 96 Buick Century (heh, yeah...) and here is the system I put together:

Kenwood Excelon KDC-X491 reciever

Infinity Reference 9613i 6"x9" 3-way speakers

Pioneer TS-G4641R 4"x6" 2-way speakers

Infinity Reference 1252w 12" dual voice coil woofer

QLogic 12" sealed woofer box

Infinity Reference 311a mono sub woofer amp (running at 2-Ohms for 312W)

Nothing too fancy. I went to that from the crappy stock system with a cassette tape adapter running an MP3 player. //content.invisioncic.com/y282845/emoticons/*******.gif.a649d21efc0d1fd4890a6428166586c1.gif

I listen pretty much strictly to metal and rock of various kinds (W.A.S.P., Korn, Behemoth, Nevermore...) and I love my bass drums more than anything.

My brother just recently put together a new system in his 2003 Chevy S10 ZR-2, and it is definitely a bit more high-end than mine (his Kenwood amp is running at 500W RMS at 2-Ohms, its capable of 900W at 1-Ohm and he has an Infinity Kappa Perfect 12 hooked up to it) but because the cab of the truck is so small and the sub is right behind the seats (facing up) it sounds incredibly clear and has a lot more punch than my system. We played Amon Amarth - Valhall Awaits me and the insane double bass felt like someone hammering on my chest with both fists. It sounded freaking amazing.

In my car, it sounds similar... in the trunk... In the front seat it sounds very muddy, like the sounds all blend together and it pretty much turns into one long bass sound, as opposed to a series of fast bass punches.

This might not be a problem listening to rap or hip hop or even bass test CDs, but I need my bass drum kick and it seems to be lost somewhere between the trunk and front seat.

I have my sub facing back. I tried it in various positions (facing up, facing forward, facing to the side...) and it seems to sound loudest farther back, facing back, but I still can't sharpen up the sound.

Is there anything I can do to remedy this situation, short of sticking the sub on my back seat? //content.invisioncic.com/y282845/emoticons/yumyum.gif.0556df42231b304b9c995aefd13928a8.gif

I've noticed that my car is extremely well sealed, especially the trunk (it IS a granny car after all), and there isn't much air movement near the rear deck. In fact, my rear 6x9s have to play through about a quarter inch of padding, which is definitely hurting the sound there too. I've heard of people porting their rear deck, but I don't know if this is something that'd help my situation or not. I know there is a ton of kick bouncing around in my trunk, but I'm not going to start chopping up the rear deck of my car just to see if that lets it flow better into the passenger area.

Any help you guys can give will be much appreciated!

EDIT: Oh, almost forgot. I have adjusted crossovers on all speakers (my head unit has separate front, rear and sub crossovers, and my amp has a crossover too) so that most likely isn't the problem.

Click to read more...

 

[frzninvt 10+ year member]

What is the crossover point and slope for the subwoofer (i.e. 80Hz/12db) 80Hz Low Pass is a good starting point.

Check the polarity + to + - to - from the amp to the woofer and make sure it's right. If it is a DVC are the coils wired in "series" or "parallel?" Series tends to sound muddy or boomy in some applications.

Make sure the amp has a solid clean grounding point.

Firstly, is the sub box the optimum size for the woofer (i.e. not too big, not too small) as it will serious affect its performance.

Make sure the sub box is completely sealed, no air leaks. Remove the woofer and put a generous bead of silicone on all the joints if it has not already been done. If the box is empty try putting a small amount of cotton batting or dacron polyfill in it to smooth it out some.

I have a sealed box and it hits hard and low if there is plenty of bass content in the music.

Nothing worse than a car coming down the road with bass that sounds like ten men beating on the side of a rubber raft. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

If you want sick "Impact" and "Punch" try getting a cheap 140W modified sine wave power inverter and run a DBX 3BX-III or 3BX-DS Dynamic Range Controller these units can increase dynamic range up to 50% and have up to 12db of Impact Restoration and can make the snap of a snare drum sound like a firecracker going off. I used one in my '94 Camaro IASCA competition vehicle and it made a tremendous difference you just have to find a place to put it since it is a home component. I had it mounted in an area below the amp rack.

 

[frzninvt 10+ year member]

The photo restrictions on this site are horrid. Here is the DBX 3BX-DS in the Camaro.

 

[CaptNKILL 10+ year member]

I have the crossover set around 80Hz on my Amp. Not sure about the slope though. How can I check that?

Polarity should be good, but I will double check it.

Amp is grounded well (with a short cable), but I'll check it again.

I know the box isn't top quality, but it seemed to be solid and well sealed. I'm pretty sure it had a bead of silicone around the inside as well.

We used this little diagram when we set it up for 2-Ohm.

http://www.infinitysystems.com/car/support/SubwooferWiring/sub_wiring_diagram.aspx?type=1-4-2

Is that series or parallel? Sorry for the noobie question.

Thanks for the help.

I'm still thinking its more related to the sound getting from the trunk to the front seats though. It sounds very punchy and clear in the trunk.

Is porting the rear deck something that really works?

 

[armitank]

wooo ****in behemoth.. wooo

 

[CaptNKILL 10+ year member]

wooo ****in behemoth.. wooo

Yep, they kick some major ***. Can't wait to see them at ozzfest this year. //content.invisioncic.com/y282845/emoticons/naughty.gif.94359f346c0f1259df8038d60b41863e.gif

Anyway, this sounds like exactly what I need:

http://www.teamrocs.com/technical/pages/trunk.htm

Has anyone done this before?

My car has a lot of "excess" steel just about everywhere around the trunk, so it has to be really limiting the clarity (and volume) of the bass in the listening area.

 

[CaptNKILL 10+ year member]

Anyone have any opinions on porting the rear deck in a situation like this? Do you think it'd help clear up the bass? Or is it just the distance thats killing me because my car is rather long?

 

[UndercoverPunk 5,000+ posts]

My subs always sounded great in my caprice.... and that's a big *** car....

Although I didn't have my rear speakers in and I did have a 12" hole in the rear deck from a previous install....

I bought a wagon for a reason. Try custom building a box. A lot of people on here have a hardon for the lower line Infinities, but my IKPs still left some to be desired. Good luck with that.

 

[CaptNKILL 10+ year member]

So it wouldn't be too far off to assume that the huge holes in your rear deck may have helped?

Or at least, that they didn't make it sound like crap, heh.

I wouldn't mind making my own box (my brother has made quite a few) but it seems like it'd require a lot of trial and error to fix my problem, and I really can't afford that.

My next system will probably have a custom box, but thats probably a long way off. $600 probably doesn't seem like much for a system compared to the kick *** stuff most people here have, but thats quite a bit for a wal-mart employee such as myself. I'm definitely going to squeeze as much out of this system as I can before I replace anything.

 

[UndercoverPunk 5,000+ posts]

Well does it sound horrible? Your box does line up perfectly with the reccomended sealed enclosure, so.... yeah.

Your car shouldn't be able to make it sound muddy all by itself.

 

[CaptNKILL 10+ year member]

Well does it sound horrible? Your box does line up perfectly with the reccomended sealed enclosure, so.... yeah.
Your car shouldn't be able to make it sound muddy all by itself.

Yeah, I made sure to get well matched components for this system. Overall it does sound pretty **** good, I just think I could greatly improve the clarity of the bass. My definition of muddy might be a bit off though.

Basically, when there is a sequence of fast, hard hitting bass drums, they tend to blend together into a loud BRRBRRBRRBRR rather than BAMBAMBAMBAM. They sound right in the trunk, but in the front seats they sound "blurred" together. Its hard to explain.

A guy on my regular forum recommended removing some sound dampening material between the sub and listening area. There is a ton of the stuff in my car (more than most I'd imagine since its a granny car). Behind the rear seats is a 3\4 inch thick pad of insulation with a plastic backing on it. The entire rear deck is covered in the stuff too.

Someone else recommended popping out the 6x9s to test the effects of "ports" in the rear deck. I just did this and it seemed to have a pretty positive effect. There is still a bunch of carpet and a weird particle-board "grill" where the speakers were (yeah, there is wood and carpet over my rear speakers... //content.invisioncic.com/y282845/emoticons/*******.gif.a649d21efc0d1fd4890a6428166586c1.gif ) so I'm sure a real port would probably help a lot more.

I also noticed that the surface of my rear deck flexes and moves a LOT with the bass, so it has to be holding in quite a bit of sound. There is steel under the deck, but for the most part its just a bunch of insulation and a bit of particle board with some carpet over it.

 

[CaptNKILL 10+ year member]

By the way, here is the discussion I'm having on my main forum:

http://www.nvnews.net/vbulletin/showthread.php?t=96733

 

[sucker4clarity]

We used this little diagram when we set it up for 2-Ohm.

Infinity - Car Audio

Is that series or parallel? Sorry for the noobie question.

Not sure if you were still wanting to know this but yes that diagram shows parallel wiring dude.

Cheers

 

[sucker4clarity]

Re: Muddy bass in sedan... can it be improved?

We used this little diagram when we set it up for 2-Ohm.

Infinity - Car Audio

Is that series or parallel? Sorry for the noobie question.

Not sure if you were still wanting to know this but yes that diagram shows parallel wiring dude.

Cheers

 

[chillin 10+ year member]

Try taking out the back speakers and see if that helps. If it does, you will know that porting the rear deck could help. Also, double kick has a lot of higher frequencies in it, it may help deadening your doors to get more midbass out of your front speakers