How Do I Adjust A Subwoofer For Best Sound?

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RustyRatRod

RustyRatRod

I was born on a Monday. Not last Monday.
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In my truck, I have a Custom Autosound head unit with receiver, cd player, usb, aux, blootoof....all that stuff. It's a 4 channel unit. I have a 6 1/4" coaxial speaker in each door and a 200w powered Blaupunkt 8" subwoofer behind the seat. It's a two channel unit wired in with coax cables. It has "volume", "crossover" and "phase" knobs. I've never gotten it to sound what I would call "real good" the whole time I've owned it. It started acting up awhile back and I removed it and put 2 6x9 coaxial speakers in 6x9 speaker boxes its place, but they sounded like infected dog butt. I found the reason the sub was acting up. The RCA connectors had some green corrosion on them. I cleaned them all up this morning and put the sub back in. It's working "good as it ever did" now, but I know it could be better. Now, I know nothing about what I'm doing, so break it down for me in stupid talk so I'll understand. lol I do appreciate any help. Thank you drive through.
 
Does the sub have it's own amp built in?

Does it have inputs from the speakers and outputs back to the speakers...

...or does it work from 2 of the 4 channels from the head unit?
 
YY1 said:
Does the sub have it's own amp built in?

Does it have inputs from the speakers and outputs back to the speakers...

...or does it work from 2 of the 4 channels from the head unit?
Click to expand...
Yes. 200W

No. It has either high level (speaker wires) or low level (RCA cables) and I'm using the RCA cables.

Yes. I have it on the "rear" channels of the head unit.
 
What speakers do you have? How much power from the head unit per channel? I went down the slippery slope of car audio a few times. Bottom line....car interiors are terrible places for high quality audio. I ended up tuning the last stereo I installed with a DSP (I went a long way into the weeds) however it did make a big difference (I had separate sub/mid/tweeters). Some stereo shops will tune your stereo for you but the sound quality is obviously limited to what speakers you have. If I was going to spend $$$ on a stereo it would be on the door speakers however I think you are going to be limited on how much power you have from the head unit.
 
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It looks like your in Georgia so this will be easy peezy for you. Play your favorite song at the sound level you appreciate. Grab your neighbor's Blue Tic Hound and when he goes woof your set.
 
Get some new hearing aids Rob, that's the direction that I am heading!
 
So...

"Phase"

Flips the phase of the speaker.
That can compensate for that speaker being a lot farther away than the others.
Flip it and see if it helps.

Crossover is liakely the pass frequency of what goes to the sub.

Anything below "X" to the sub, anything above to the regular spealers.
 
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I'm assuming your not looking for overbearing bass, It's been a few years since I setup a stereo, I'd watch some YouTube videos 1st, from what I remember off the top of my head, turn down all the amps gains and turn the sub volume all the way down, turn deck up until it starts to distort then back it off a bit, that's max volume for that deck, now turn up the gains to the high and mids so you have good clean volume shouldn't be anywhere near maxed out, if you feel the need to max them out you don't have enough amplifier, then turn up the bass so you can hear it well adjust the gains for good clean volume with no distortion, then adjust the volume of the sub to where it sits in the mix where you like it. Again gains shouldn't be cranked, and if you find you need to crank the sub, there's a chance it not more bass your looking for but trying to make-up for lack of mids and highs. Shouldn't need too much gain to do any of this unless your deck has super low output.

This video might help.

 
As for the crossover;
Where you set it will depend on at what frequency your main speakers quit making base. You will need some material with deep base content; not kick-drums. I like blues so I'm always after hearing the stand-up base. Drums have a high attack speed and your brain will choke them right quick to protect your ears. Use a cello or a tuba, yeah those are great.
Do not use a max volume setting on the mains. Your ears will only be accurate over a small window, so set the volume to the level that you will normally be listening to. Leave the subs off. Get familiar with the material for a few hours.
After you know where the base disappears, now turn on your subs at low power. If the base from the subs is out of phase with that of the mains, the base will go quiet as your brain tries to figure it out. If you find yourself cranking the subs up, go back and reverse the phase and see what happens.
Adjust the crossover frequency higher until the base from the subs unites with the base from the mains, and begins to be excessive or annoying, then turn it to a lower frequency. As you turn it to a lower frequency, the base is bound to get quieter, so then turn the volume or gain, of the subs higher.
As you sort it out, and after you have it phased right, it will become a game of twiddling the gain and frequency to find a sweet spot. On the day that you find it, mark the knobs so you can get back to the sweetspot, if perchance you move them, then yur ready for other material.
When you switch between blues to classical to rock to chamber music, you may find yourself twiddling the knobs again, so those marks could come in handy.
 
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1MeanA said:
What speakers do you have? How much power from the head unit per channel? I went down the slippery slope of car audio a few times. Bottom line....car interiors are terrible places for high quality audio. I ended up tuning the last stereo I installed with a DSP (I went a long way into the weeds) however it did make a big difference (I had separate sub/mid/tweeters). Some stereo shops will tune your stereo for you but the sound quality is obviously limited to what speakers you have. If I was going to spend $$$ on a stereo it would be on the door speakers however I think you are going to be limited on how much power you have from the head unit.
Click to expand...
Head unit is 4 x 40w. It's this one:
www.vintagecarradio.com

Custom AutoSound USA-4 In Dash AM/FM/CD MP3 2 with Bluetooth

Custom AutoSound USA-4 in Dash AM/FM/CD MP3
www.vintagecarradio.com www.vintagecarradio.com

The door speakers are Kenwood 6.5" coaxials. I don't remember which exact ones. The sub as I said is a powered 8". This is the sub:
www.crutchfield.com

Blaupunkt THb 210A

Compact powered subwoofer 120-watt amp with an 8" sub
www.crutchfield.com www.crutchfield.com
 
273 said:
I'm assuming your not looking for overbearing bass, It's been a few years since I setup a stereo, I'd watch some YouTube videos 1st, from what I remember off the top of my head, turn down all the amps gains and turn the sub volume all the way down, turn deck up until it starts to distort then back it off a bit, that's max volume for that deck, now turn up the gains to the high and mids so you have good clean volume shouldn't be anywhere near maxed out, if you feel the need to max them out you don't have enough amplifier, then turn up the bass so you can hear it well adjust the gains for good clean volume with no distortion, then adjust the volume of the sub to where it sits in the mix where you like it. Again gains shouldn't be cranked, and if you find you need to crank the sub, there's a chance it not more bass your looking for but trying to make-up for lack of mids and highs. Shouldn't need too much gain to do any of this unless your deck has super low output.

This video might help.

Click to expand...

I went out and tuned it like you described and it made a nice difference. So that's gainin on it. lol
 
YY1 said:
So...

"Phase"

Flips the phase of the speaker.
That can compensate for that speaker being a lot farther away than the others.
Flip it and see if it helps.

Crossove is liakely the pass frequency of what goes to the sub.

Anything below "X" to the sub, anything above to the regular spealers.
Click to expand...
To "MY" ears, the crossover "seems" to cut the highs in and out. Turned all the way "up" I get more midrange and highs along with the bass and it has more overall volume, if that makes sense. Turned all the way "down" all I get is the deep bass and nothing else. I still ain't figured out WTF phase does. I can hear a difference when I adjust it, but I don't know a dang thing about what I'm doing, so I put the phase in the middle, or what they call "flat".
 
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RustyRatRod said:
To "MY" ears, the crossover "seems" to cut the highs in and out. Turned all the way "up" I get more midrange and highs along with the bass and it has move overall volume, if that makes sense. Turned all the way "down" all I get is the deep bass and nothing else. I still ain't figured out WTF phase does. I can hear a difference when I adjust it, but I don't know a dang thing about what I'm doing, so I put the phase in the middle, or what they call "flat".
Click to expand...
Phase is if the speakers are in sync with one another, say you got two subs and you wire the positive from the amp to the positive to each speaker same with negatives then both speakers will move in and out together at the same time so in phase but if you wire one sub backwards then it will be a 180* out of phase they move in opposite directions cancelling each other out getting zero sounds.

Now that's 100% in phase and a 100% out of phase and is a wiring issue but you can also be degrees of in between, If i remember right you play guitar that's what phase/flanger pedals do it slightly alters the sync and you get that Jimi Hendrix sound. So in a car if you have some sub frequency coming out of other speakers besides the sub they can arrive to you ears at different times given a out of phase sound so you can adjust the phase to try to get the best compromise if phase is being an issue.
 
Crossover is designed to only send select frequency to each speaker, the sub should be using a low pass filter set somewhere between 80-120 hz and if the others are full range speakers (woofer and tweeter in one speaker) then you can use a high pass filter on them set somewhere from 80-120 hz or no filter at all,
But no filter can cause phase issues now there also playing sub frequency and probably handle less volume cause there also playing sub frequencies. Sub really needs a low pass filter on full range it's optional.

Low pass filter only lets the frequencies pass under the set amount 80-120 hz and under, high pass does the opposite.
 
273 said:
Crossover is designed to only send select frequency to each speaker, the sub should be using a low pass filter set somewhere between 80-120 hz and if the others are full range speakers (woofer and tweeter in one speaker) then you can use a high pass filter on them set somewhere from 80-120 hz or no filter at all,
But no filter can cause phase issues now there also playing sub frequency and probably handle less volume cause there also playing sub frequencies. Sub really needs a low pass filter on full range it's optional.

Low pass filter only lets the frequencies pass under the set amount 80-120 hz and under, high pass does the opposite.
Click to expand...
Yeah that cleared it right on up.
 
RustyRatRod said:
To "MY" ears, the crossover "seems" to cut the highs in and out. Turned all the way "up" I get more midrange and highs along with the bass and it has more overall volume, if that makes sense. Turned all the way "down" all I get is the deep bass and nothing else.
Click to expand...
That's a low pass filter


Do you only have one amp powering both sub mids and high ?

If so you might have to wire in passive filters between amp and speakers.

1715737765362.png
 
273 said:
That's a low pass filter


Do you only have one amp powering both sub mids and high ?

If so you might have to wire in passive filters between amp and speakers.

View attachment 1716249928
Click to expand...
The sub only has one 8" speaker. It's an all in one unit. I posted a link to it up there ^^^^
 
RustyRatRod said:
The sub only has one 8" speaker. It's an all in one unit. I posted a link to it up there ^^^^
Click to expand...
Kool so yeah just set the filter where it sounds best to you then probably around 80-100 hz. There's probably no filter to the fronts so it is what it is for them.
 
273 said:
Kool so yeah just set the filter where it sounds best to you then probably around 80-100 hz. There's probably no filter to the fronts so it is what it is for them.
Click to expand...
I put a filter on the fronts to limit bass output since they are small and would distort easily.
 
RustyRatRod said:
Like I know what that is. LMAO
Click to expand...
Might take some experimenting then, play songs you know the bass really well and play with it until it sounds right. If some of the notes go missing or quieter then there might be a gap in the frequency and the crossover set too low.
 
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