Sub is muddy - need crossover?

[UCbizerkeley 10+ year member]

Ok, so I am very uneducated about car audio, but have been doing my best to read and BECOME educated ASAP. I have spent the last two days wiring my car, and finally got to try things out, only to be a tad let down. So here is what I have going so far:

My car: 1990 735i BMW (has a stock amp, that feeds 30w to speakers. Will come back to this)

Sub: 1x Alpine Type R 12" (500 RMS, 2 ohm)

1 cubic foot sealed Kicker Box

JL Audio 500/1 Amp

Head unit - Panasonic cq-df583u

Ok, so I ran the preamps from my amp to the back of my aftermarket head unit, which has 4 RCA jacks (2 front, 2 rear). At first, I just plugged into the rear two jacks, then got an adapter to plug 2 RCA jacks into the 4. This made the sub louder, but not any less muddy. This wiring was direct - I have no crossover installed to my knowledge, unless there is one in my headunit (which I doubt).

I am wondering how I should be wiring this, because as I have it, the sub is distorted, muddy and basically lackluster - I have heard great things about the abilities of the Type R (even 1) and I believe my wiring has to change.

At current, when I adjust the bass settings on my head unit (raising or lowing bass dB and/or turning on/off bass booster) it affects both my sub AND my speakers. THis is not at all what I want, since I have read it is superior to let the sub handle the bass and the speakers the mids and highs. Can I achieve this with just the RCA jacks on my head unit?

Thanks for eveyrones help - I can't wait to get everything aligned

lastly - the head unit supplies 50x4 or 12.5 watts to each speaker. This would mean each speaker I have is receiving 42.5 watts I guess (since they are factory rated at 30) and become distorted quite easily as i raise volume. Solutions?

Click to read more...

 

[dleccord 5,000+ posts]

did you buy your equipment used?

 

[jinx8402 10+ year member]

Yes, Definitely use a crossover on your sub. Your amp should have one on it, so you won't even need to buy one. I'm not particularly familiar with that amp. But just look at the controls, and look to see for a knob that is labeled crossover. Make sure it is set for low pass, which it should be since it's a mono sub amp. Set the crossover point to anywhere between 50hz-100hz, depending on how it sounds to you. Also, make sure the gains are not set too high. That can cause the subs to clip, and potentially blow them. There is a nice gain setting tutorial on here that will show you how to set the gain properly.

Also, you hu is probably only putting out 12.5 watts to each speaker. The 50x4 is a marketing ploy basically. That is the max output of the internal amp...but it will probably never put that out

 

[DBfan187 5,000+ posts]

:fyi:subs don't clip and clipping doesn't hurt speakers.

 

[UCbizerkeley 10+ year member]

did you buy your equipment used?

Yes, please elaborate? The condition is like-new. Is there a way to test components, like a diagnostic?

 

[ItalynStylion 10+ year member]

Like Jinx was saying, set your crossover somewhere under 100. I like mine set at 80hz. My subs will play 100hz just fine but it pulls the sound stage back a little.

 

[UCbizerkeley 10+ year member]

Yes, Definitely use a crossover on your sub. Your amp should have one on it, so you won't even need to buy one. I'm not particularly familiar with that amp. But just look at the controls, and look to see for a knob that is labeled crossover. Make sure it is set for low pass, which it should be since it's a mono sub amp. Set the crossover point to anywhere between 50hz-100hz, depending on how it sounds to you. Also, make sure the gains are not set too high. That can cause the subs to clip, and potentially blow them. There is a nice gain setting tutorial on here that will show you how to set the gain properly.
Also, you hu is probably only putting out 12.5 watts to each speaker. The 50x4 is a marketing ploy basically. That is the max output of the internal amp...but it will probably never put that out

I will perform this to the best of my ability, although I do not recall a "Crossover" knob. However, I am probably mistaken! More updates to come after I get back from work.

Have a good day everyone

 

[2kchevy06civic 5,000+ posts]

:fyi:subs don't clip and clipping doesn't hurt speakers.

//content.invisioncic.com/y282845/emoticons/suave.gif.858fc102f7646e678ee8af7e1fbc41d1.gif :suave:

 

[DBfan187 5,000+ posts]

50Hz and down is where mine play. //content.invisioncic.com/y282845/emoticons/cool.gif.3bcaf8f141236c00f8044d07150e34f7.gif

 

[jinx8402 10+ year member]

//content.invisioncic.com/y282845/emoticons/suave.gif.858fc102f7646e678ee8af7e1fbc41d1.gif :suave:

//content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

Yeah, I worded it wrong...but you get the idea lol.

I meant to say so the amp doesn't send a clipped signal to the sub

 

[UCbizerkeley 10+ year member]

Sounds much better. I am saddened that my head unit does NOT have crossover, so i can't tell the front speakers to only play above 80Hz. Lame.

 

[ZeroSktr56 10+ year member]

Sounds much better. I am saddened that my head unit does NOT have crossover, so i can't tell the front speakers to only play above 80Hz. Lame.

The first hu i ever bought didn't have one either so I took it back and bought one that did. It made a great difference. Maybe you should do the same?