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Discussion Starter · #1 ·
Hey guys,

I'm having a few problems with my setup. I've been running it for the past year and a half and I've had enough. My problems only occur when I'm sitting in the driver or passenger seat, also. If I sit in the back of my car (2001 Jeep Cherokee), then the system sounds about as perfect as a system with bad speakers on HU power can sound.

Problems in the front seat:

1. The bass seems to be delayed or slowly fall behind.
2. Around 80Hz or so is non existent.

My system isn't the best. I've got a sealed 10" Type R at 900W (box is ~0.8ft^3 to save space, and it's filled with Polyfill), Hifonics BRZ1200.1D, JVC KDR730BT, and crappy pioneer speakers on HU power. I assumed that the midbass problem was due to the speakers, but since the midbass sounds balanced when sitting in the back seat, I don't think that's the problem. Could the midbass issues be the lack of deadening in the front doors? I'm not sure if the soundbar has deadening, but the speakers in it produce considerably louder midbass. Also, I've checked the phase of speakers, and they're all in phase.

Any ideas?
 

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Hey guys,

I'm having a few problems with my setup. I've been running it for the past year and a half and I've had enough. My problems only occur when I'm sitting in the driver or passenger seat, also. If I sit in the back of my car (2001 Jeep Cherokee), then the system sounds about as perfect as a system with bad speakers on HU power can sound.

Problems in the front seat:

1. The bass seems to be delayed or slowly fall behind.
2. Around 80Hz or so is non existent.

My system isn't the best. I've got a sealed 10" Type R at 900W (box is ~0.8ft^3 to save space, and it's filled with Polyfill), Hifonics BRZ1200.1D, JVC KDR730BT, and crappy pioneer speakers on HU power. I assumed that the midbass problem was due to the speakers, but since the midbass sounds balanced when sitting in the back seat, I don't think that's the problem. Could the midbass issues be the lack of deadening in the front doors? I'm not sure if the soundbar has deadening, but the speakers in it produce considerably louder midbass. Also, I've checked the phase of speakers, and they're all in phase.

Any ideas?
^^^this is your problem.

you have 900+ watts of power on a sub and 50 watts of HU power going to "crappy" midbass speakers.

replace the crappy midbasses with something that will play down to 70-80 hz with real authority and get an amplifier that puts out a REAL 100 watts per channel.

also where is the LPF for the sub set? try bumping it up to 80hz or so to fill in where the mids cant.
 

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Discussion Starter · #3 ·
^^^this is your problem.

you have 900+ watts of power on a sub and 50 watts of HU power going to "crappy" midbass speakers.

replace the crappy midbasses with something that will play down to 70-80 hz with real authority and get an amplifier that puts out a REAL 100 watts per channel.

also where is the LPF for the sub set? try bumping it up to 80hz or so to fill in where the mids cant.
I'm definitely going to replace the speakers over winter break when I have time, and I'm going to amp them. I've been wanting to do that for a while. The sub LPF is around 90Hz or so.

Would the HU power really be the issue, though? I get plenty of midbass when sitting in the back seat, but in the front, there's almost nothing.

Also, any ideas as to why the sub is so sloppy?
 

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I'm definitely going to replace the speakers over winter break when I have time, and I'm going to amp them. I've been wanting to do that for a while. The sub LPF is around 90Hz or so.

Would the HU power really be the issue, though? I get plenty of midbass when sitting in the back seat, but in the front, there's almost nothing.
yes, it really is an issue. most aftermarket HUs put out about 18watts per channel. stock ones, even less. get a good midbass upfront and enough power to drive it and then you will see alot of the problem go away. at the very least you will have something to work with. right now your system has no power, and self admitted "crappy" mids. not much to work with. ;)
Also, any ideas as to why the sub is so sloppy?
could very easily be that the mids dont mesh well with it because of the limited power and no midbass.

someone else will have to confirm this, but I think 0.8cuft is bit small for the Type R as well.
 

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Discussion Starter · #5 ·
yes, it really is an issue. most aftermarket HUs put out about 18watts per channel. stock ones, even less. get a good midbass upfront and enough power to drive it and then you will see alot of the problem go away. at the very least you will have something to work with. right now your system has no power, and self admitted "crappy" mids. not much to work with. ;)

could very easily be that the mids dont mesh well with it because of the limited power and no midbass.

someone else will have to confirm this, but I think 0.8cuft is bit small for the Type R as well.
Okay, that's what I was hoping. I'm not too knowledgeable about what speakers I should get. I was thinking Type Rs, but people I've talked to said Hertz is awesome and Alpine is just paying for the name, which wouldn't surprise me.

Alpine suggests .5 to 1.0 ft^3 for the Type R 10, so I'm not sure that's the problem.

Also, I was thinking of maybe getting a new sub for the box and a new sub amp. Maybe a Sundown? Not too sure. I don't wanna change the box, though, since it's a cubby box that doesn't take up much trunk space.
 

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It's also the jeep. The rear doors have a completely different response than the front doors.

Seal the front doors with some deadener and it will really help
 

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It could also be issues with time alignment.
 

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How do you know it's precisely 80 hz? An Alpine Type R 10 in a .9 sealed box has a specific peak right at 70 hz. So in an open top jeep 80hz ought to be right at the peak. Considering how little power the mains have I doubt they'd have enough power to cancel anything the subwoofer would be putting out. I suggest playing test tones to see where exactly the dead zones in frequency response are. Just trying to guess what frequencies a subwoofer is playing based on music is an exercise in futility if you're not thoroughly familiar with what the frequencies really sound like.

I'd check how the crossovers are set and if any processing is being done by the headunit, or any bass bosts are one. If all three of those are combined I would think the subwoofer would definitely not be reproducing higher bass with any authority.
 

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Just rereading. It's not an open top but it is a Jeep Cherokee. A car which I did use to own. That particular car with it's long length and short height and very straight walls that had your head very close to the windshield was just very strange in how it had a lot of standing waves.

Try leaning forwards and backwards and see just how much that can change how your bass sounds. It kinda sucks but the acoustics of the Cherokee positively sucked. I actually got my best bass response by running a low tuned ported sub in back, crossing it over low around 50hz and mounting an 8" sealed midbass right behind the center console. That helped smooth out the frequency response and since I never used the center of the rear seat to carry a passenger having a 4 passenger car wasn't too bad, and if I really needed to I can just tell the middle person to straddle the 8" subwoofer lol.
 

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Discussion Starter · #10 ·
It's also the jeep. The rear doors have a completely different response than the front doors.

Seal the front doors with some deadener and it will really help
There are no rear door speakers. Just the speakers in the roof (which I think are sealed), and the front door speakers.

It could also be issues with time alignment.
I thought about this, but I can't really test this since my HU has no time alignment options.

How do you know it's precisely 80 hz? An Alpine Type R 10 in a .9 sealed box has a specific peak right at 70 hz. So in an open top jeep 80hz ought to be right at the peak. Considering how little power the mains have I doubt they'd have enough power to cancel anything the subwoofer would be putting out. I suggest playing test tones to see where exactly the dead zones in frequency response are. Just trying to guess what frequencies a subwoofer is playing based on music is an exercise in futility if you're not thoroughly familiar with what the frequencies really sound like.

I'd check how the crossovers are set and if any processing is being done by the headunit, or any bass bosts are one. If all three of those are combined I would think the subwoofer would definitely not be reproducing higher bass with any authority.

-------------------------------------------------

Just rereading. It's not an open top but it is a Jeep Cherokee. A car which I did use to own. That particular car with it's long length and short height and very straight walls that had your head very close to the windshield was just very strange in how it had a lot of standing waves.

Try leaning forwards and backwards and see just how much that can change how your bass sounds. It kinda sucks but the acoustics of the Cherokee positively sucked. I actually got my best bass response by running a low tuned ported sub in back, crossing it over low around 50hz and mounting an 8" sealed midbass right behind the center console. That helped smooth out the frequency response and since I never used the center of the rear seat to carry a passenger having a 4 passenger car wasn't too bad, and if I really needed to I can just tell the middle person to straddle the 8" subwoofer lol.
I know it's precisely 80 Hz because I was using a tone generator app on my phone to see exactly where the sound is most dead. Around 80 Hz I basically couldn't hear anything in the driver's seat. No bass boosts are on, and the sub LPF is around 90-100 Hz and the speaker HPF is about 80 Hz.

I agree about the weird Cherokee acoustics. If I lean all the way over the steering wheel, the midbass comes back. If I open the driver door, the midbass comes back (though with the window open, it doesn't do anything). In the back seat, the midbass is fine. So I'm not too sure what's causing this unless the Cherokee just has weird acoustics. Even if my head is laying on the driver seat, I hear the midbass just fine. It's basically a box around my head where the midbass is gone.

I frequently take the doors off my Jeep, so I was thinking of maybe ditching the door speakers and doing a second soundbar right behind the front seats. Maybe that would alleviate the problem.
 

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Yup that midbass dip is in a very specific part right where your head is at. Kinda sucks. That's specifically why I ran a separate dedicated midbass right behind the center console.

Unfortunately even if you get your door speakers boosted in the midbass, unless you completely redo everything in the doors, they'll rattle like crazy, just a lot of loose hardware and the flat panels tend to really resonate and rattle.
 

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Mine was an 1988 Cherokee Limited. But the shape of the car has never really changed so the acoustics would be poor all around, the only difference, maybe the newer cars don't rattle as much.
 

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Discussion Starter · #14 · (Edited)
Yup that midbass dip is in a very specific part right where your head is at. Kinda sucks. That's specifically why I ran a separate dedicated midbass right behind the center console.

Unfortunately even if you get your door speakers boosted in the midbass, unless you completely redo everything in the doors, they'll rattle like crazy, just a lot of loose hardware and the flat panels tend to really resonate and rattle.

--------------------------

Mine was an 1988 Cherokee Limited. But the shape of the car has never really changed so the acoustics would be poor all around, the only difference, maybe the newer cars don't rattle as much.
Yeah, mine just about rattle now (especially if I EQ the 80 Hz area). I might just do a soundbar behind the front seats and be done with it. Kind of sucks that the XJs suck for sound, though.

I'm gonna try Dynamatting the front doors and seeing if that helps at all. I know the doors have no soundproofing and therefore the speakers aren't sealed at all. Maybe it would help.
 
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