Trouble playing higher bass notes - 60-80hz

[clsnwbrdr616]

Hi, I've been having a problem with my setup and any information would be appreciated.

I have a basic setup, aftermarket head unit, amp and sub in my '02 Grand Am SE. I like to listen to dubstep and trance music mainly. The dubstep sounds great with the heavy low notes, but with dubstep and trance with some higher bass notes (more in the 80hz range) the volume from the sub just plummits. Its really jarring when a song plays a range of bass and when the bass is down in the 40-50hz range it hits really hard and then when the bass goes a little higher to 70-80hz the volume just plummits. I'm more of an SQ guy than a SPL guy so this continues to bug me.

And this is not a crossover issue as I have thoroughly checked those. HU is set at 100hz and amp is set at max 250hz (since the head unit is at 100).

Setup:

HU:Sony CDX-GT65UIW

Amp:Kicker DX1000 - 1000w Mono, 500rms at 4ohms

Sub:Rockford Fosgate Punch P3 10" 1000w (500rms) wired at 4 ohms in a sealed box

I've used a climbing test tone scale (from 40hz to 200hz, at 10hz increments) to confirm the volume drop as hz go up and the volume drops slightly at 60hz and drops really fast after that until 80hz where the volume from the sub is only slightly less then my car speakers until 100hz (the crossover) and then it starts to drop from there (like it should).

I originally had a 4 channel lanzar amp 2000w, but tried the kicker amp thinking it was the amp causing this phenomenon. It did not fix the problem, but the kicker amp sounded WAY better and ran cooler than the cheap lanzar one so I kept it. I even tried hooking up my brothers kenwood HU thinking it was the HU, but still the same phenomenon. Lastly the box I had was .85 cu ft volume and the sub recommend .5-.7 so I got a .7 box thinking that might fix it, but no I still have the same problem. The only thing left that I haven't replaced/swapped is the sub. I figured since it was a rockford sub it would be high quality and that it wouldn't have been the problem (not saying you can't get a lemon every once in a while). The only thing is I used to have a cheap 500w sony sub in my car a long time ago (before the rockford one) and I seem to recall this same phenomenon back then. It just wasn't as jarring because it wasn't as loud as my 1000w RF sub. The RF sub sounds great below 60hz and hits really hard otherwise. I even tried wiring it at 2 ohms just to test and it had no effect. So I've technically tried selectively replacing/swapping out every component in my system to find the culprit and the problem still persists regardless. Everything else about my audio system works fine, I've had absolutely no other issues.

Can car subs just not play 60-80 hz (seems unlikely)? Is it my car? I've heard things about cabin gain in small cars. Is it just that car is small and it makes the lower hz sound LOUDER than the 80hz and thats what I'm noticing or is there something else that I'm missing here. I'm just picky about sound quality and don't like the volume difference when I know the songs don't sound like that when listen to them at home on nice headphones or my home theater system. Any help/input would be appreciated, thanks.

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[IonRL205 10+ year member]

It's a box issue

I always had trouble playing higher bass with every sealed setup I had.

 

[clsnwbrdr616]

So would a ported box even it out? I was under the impression that a ported box boosts the lower frequencies even more and sealed gives a more flat response.

 

[Jroo 10+ year member]

It sounds like a box issue to me, but dont Ive never been a ported guy so cant say that will help. I have always had sealed boxes and the size of the sealed always changed the range. On some systems, if i went smaller on the box, I was able to pick up more higher bass heading up to midbass. Some of those boxes could pick up the 100 hz range real easy, but lost a lot on the low end. My bigger than sealed boxes always had better low end but you lost the high end in some cases. I would really look at getting a good design from someone.

 

[hispls 5,000+ posts]

First I would try crossing over the head unit even higher if you have the option. It still may be your crossovers attenuating.

Second, I'd do a lot of experimenting with box position, aiming, and location. This can make a dramatic difference!

Lastly try running the sub out of phase. Often times just where the sub blends in with your mids creates a null due to phase issues. Running things out of phase sometimes helps.

Small sealed box shouldn't attenuate high frequencies so you can probably find a solution elsewhere.

 

[wickedwitt 10+ year member]

Honestly, that should be roughly the area between your mid drivers and your subs crossovers. Between the two of them, they should cover that area. You may have your high pass set too high on your mids. The power typically put on subs means they get quite hot at frequencies this high, as they are unable to implement any of their cooling features due to the fact that they do not excurt.

If lowering your high pass to -12db slope @ 80hz does not solve this issue, you have cancellation between your box and the vehicle cabin.

 

[clsnwbrdr616]

First I would try crossing over the head unit even higher if you have the option. It still may be your crossovers attenuating.
Second, I'd do a lot of experimenting with box position, aiming, and location. This can make a dramatic difference!

Lastly try running the sub out of phase. Often times just where the sub blends in with your mids creates a null due to phase issues. Running things out of phase sometimes helps.

Small sealed box shouldn't attenuate high frequencies so you can probably find a solution elsewhere.

Thanks, I have actually tried all of those things in the past. Upped the CO, reversed the phase and moved the sub to different places in the trunk and faced it different directions. They didn't alleviate the issue.

Honestly, that should be roughly the area between your mid drivers and your subs crossovers. Between the two of them, they should cover that area. You may have your high pass set too high on your mids. The power typically put on subs means they get quite hot at frequencies this hot, as they are unable to implement any of their cooling features due to the fact that they do not excurt.

My high pass is actually set at 80 (some overlap). Raising it or lowering has had no effect.

If lowering your high pass to -12db slope @ 80hz does not solve this issue, you have cancellation between your box and the vehicle cabin.

I have suspected this or cabin gain, one of the two or both but wasn't sure. I should mention that if I'm in my car with windows closed and pop the trunk while playing music, the low frequencies (40-60hz) volume drops (as well as over all volume) and the frequencies seem to even out a bit more, but I obviously lose the strength of the lower tones as the pressure can escape out the back then. Also it seems that if I try to have my mids play even lower than 80hz I seem to notice the same effect with the volume but not as great of an effect as they are obviously not as powerful as my sub. Similar to my weaker Sony sub before the Rockford one. That really has me wondering if its just my car and gain/cancellation.

 

[clsnwbrdr616]

It sounds like a box issue to me, but dont Ive never been a ported guy so cant say that will help. I have always had sealed boxes and the size of the sealed always changed the range. On some systems, if i went smaller on the box, I was able to pick up more higher bass heading up to midbass. Some of those boxes could pick up the 100 hz range real easy, but lost a lot on the low end. My bigger than sealed boxes always had better low end but you lost the high end in some cases. I would really look at getting a good design from someone.

My rockford sub does recommend a volume of .59 which is smaller than the .7 I have now, so that may help if you are correct. I've thought about building one myself or getting a custom one built to spec. The sub comes with recommend dimensions. I may try that if its not cancellation or other issue.

 

[n8skow 10+ year member]

this...

Check into beefing up your mid-bass with a couple 8's or multiple 6.5s/5.25s

Honestly, that should be roughly the area between your mid drivers and your subs crossovers. Between the two of them, they should cover that area. You may have your high pass set too high on your mids. The power typically put on subs means they get quite hot at frequencies this hot, as they are unable to implement any of their cooling features due to the fact that they do not excurt.
If lowering your high pass to -12db slope @ 80hz does not solve this issue, you have cancellation between your box and the vehicle cabin.

 

[clsnwbrdr616]

^^^^

I actually have the my mids powered by the old lanzar amp. I have some 400w (120rms) kenwood 6x9s in the rear deck. They can actually put out a good amount of bass if I set the high pass low enough so I don't feel they are underpowered. I mentioned somewhere above that I feel like I get the same effect in volume changes even from them. Which makes me think its cabin gain or cancellation. Is there anyway to adjust for cabin gain/cancellation other than EQing it out.

 

[Jeffdachef 5,000+ posts]

i used to have this problem too. Tried several boxes both ported and sealed small and large, checked for cancellation, upped the power, nothing worked. Finally i switched out my subwoofers with an SQ sub with stiff spiders and the problem was solved. All subs are made to 30-50 hz bass but few can hit that 60-80 well and cleanly.

But before this, just try to get a good ported box thats designed for SQ music tuned a lil higher(NOT ALL OF US WANT TO PLAY DECAF 24/7) with a smooth frequency response chart.

 

[Jeffdachef 5,000+ posts]

i totally feel you when you say how annoying it is to have a sharp drop in that hz range, music sounds soo sh1tty and lifeless without it.

 

[Bass911 10+ year member]

I'm having the same problem with one sealed re srx12 in 1.25cu ft. The box is bigger than recommended. It picks up the lowest lows, but probably falls off around 55-60hz. I don't think a smaller box will fix it? I might try a different sub. I know for sure that the Pioneer, Sony, and Kenwood subs with pick up the higher bass notes, but I don't want any of those subs. I know it sounds like a bad suggestion, but the AUDIOBAHN AW1251M picks all the highs and lows in sealed.