Harman Kardon too much bass

[Hackmunch]

you could allways disconnect the sub at the amp under the driverseat or at the sub enclosure. the speaker wires are on the outside of the sub box near the bottom.

 

[ExcursionDiesel]

I am with you guys. The bass is muddy and overpowering. The EQ leaves little room for adjustment. Given there is no way to change it we all have to live with it I guess.

In pro-audio, we tune the room before we tune the system when possible. In this case, we can't tune the system adequately because the EQ lacks the boost/cut range and number of bands needed. Tuning the room usually envolves moving speakers and adding sound absorbing materials. We can't move the sub and the cab is small so there is no better or worse location. All we have is sound absorbing materials.

That being said, using a "bass trap" helps tame the low frequencies some. My first attempt was with a heavy shipping blanket folded into an 8" x 72" size and placed low behind the back seat. It does attenuate the bass some and tightens the response a little. I have some studio acoustic foam I may place behind and under the back seat as my next attempt.

I will fill the sub with polyfill when I get a chance and will see if it is more effective at tightening the bass response and help the muddy bass sound.

 

[ExcursionDiesel]

you could allways disconnect the sub at the amp under the driverseat or at the sub enclosure. the speaker wires are on the outside of the sub box near the bottom.

Good idea.

Another idea is to connect a large capacitor in series with the amps output. This creates a high-pass filter. A properly sized cap would roll off the bass at 3db per octave. If the -3db point is set to 150hz by proper cap selection then the bass at 75hz would be -6db and 37hz would be down -6db. A cap half that size would double the attenuation .

The downside is that the Active Noise Cancellation would be effected to some degree.

 

[Rototerrier]

Well, I have the truck in service now....they were receptive to my complaint and took in all my info. I can at least say I've tried. I'll let everyone know what happens. Maybe they'll find something wrong. I'll stay positive

 

[Rototerrier]

I have a little good news. They said they are aware of this issue thru STAR and that an update is due to be released soon to address it. I'll dig a little deeper once I get back with the SA to get as much detail as possible. But, nothing getting fixed for now, but at least they are aware and a fix is in the works.

 

[Rototerrier]

Didn't get any more info. Just the Invoice....final result: "Chrysler has an update coming out, no repairs at this time"

Guess I'll hold off on stuffing the sub or anything else and hopefully the wait for the update won't be too long. Will just continue to let my ears bleed in the meantime.

 

[Hackmunch]

Good idea.

Another idea is to connect a large capacitor in series with the amps output. This creates a high-pass filter. A properly sized cap would roll off the bass at 3db per octave. If the -3db point is set to 150hz by proper cap selection then the bass at 75hz would be -6db and 37hz would be down -6db. A cap half that size would double the attenuation .

The downside is that the Active Noise Cancellation would be effected to some degree.

a capacitor of at least 50vac would be fine. max i scoped out of the alpine amp was 18vac on output for the sub channel

 

[MJP]

Didn't get any more info. Just the Invoice....final result: "Chrysler has an update coming out, no repairs at this time"

Guess I'll hold off on stuffing the sub or anything else and hopefully the wait for the update won't be too long. Will just continue to let my ears bleed in the meantime.

Thanks for the info. Keep us posted.

 

[greatone99]

I use the app Spotify to listen to music ,and they have an equalizer in the app ,mine sounds best adjusted to rock and tweaking from there bass is plus 4 ,mid set to 0 ,treble set to 5 , mine is a 2019 rebel withe the harmon Kardon ,I'm pretty sure its updated ,its loud

 

[Goatmann]

I have mine set at bass -6 mid +2 treble or highs +2. I think it's perfect

I also have bass, and mid the same, but treble set to +6. I have upgraded to the JBL 302’s in the dash.

 

[vinnie45acp]

After changing out the 3.5 JBLs I had to the much higher sensitivity of the Hertz 3.5’s, I was able to raise my bass and mid back up. Seems after the amp update, the fronts couldn’t keep up with bass.

After more messing around I’m at -1 bass, flat on mid and +2 on the treble. The JBLs would get real harsh beyond -2 mid and anything above flat on the treble to my ears. I had to keep the bass around -6 to -7.

To me the sound is fuller now. With the bass cranked down it didn’t sound right. Missing the Low end to male voices.

I have read most of your entries, what exactly did you replace in your HK system, cause I have looked the Hertz as well but want to change out everything and want to get as much info as possible and everyones take on what they have done and how well it changed things.

 

[jdanek]

In pro-audio, we tune the room before we tune the system when possible. In this case, we can't tune the system adequately because the EQ lacks the boost/cut range and number of bands needed. Tuning the room usually envolves moving speakers and adding sound absorbing materials. We can't move the sub and the cab is small so there is no better or worse location. All we have is sound absorbing materials.

That being said, using a "bass trap" helps tame the low frequencies some. My first attempt was with a heavy shipping blanket folded into an 8" x 72" size and placed low behind the back seat. It does attenuate the bass some and tightens the response a little. I have some studio acoustic foam I may place behind and under the back seat as my next attempt.

I will fill the sub with polyfill when I get a chance and will see if it is more effective at tightening the bass response and help the muddy bass sound.

Agree, the HK sub is way too boomy. If I lower the bass setting then there's no punch from the other woofers. Having a separate sub-woofer control on the equalization panel would have been helpful.

So I wedged a large shipping blanket between the rear seat back and sub along with a towel behind the cardboard panel. It worked surprisingly well! I now have the bass set to +2. It sounds tight and delivers a punch you can feel.

I was going to try the inline capacitor mod but don't think it's necessary now. I suspect the blanket not only reduces the sub's volume but somehow tightens it up in the process.

Ideally Ram will fix this with a s/w update. Until then I think the blanket fix may be acceptable.

Thanks,
jdanek

 

[392DCGC]

The current amplifier update has been live for awhile... I'd have expected it to be fixed by now, so it may never get fixed unless enough people complain directly to FCA/RAM. I frankly don't know how it got signed off in the first place. Whatever idiot audio engineer for FCA created this mess needs fired. The HK amplifier is boosting bass in a bell curve around 90 Hz. The only way to defeat it is by disconnecting the sub from the factory amp... turning down the bass on the EQ won't fix it, and kills your 6x9 bass as well as male vocals in the other speakers. You either go without a sub, or you find a solution, which there are a few.

1. PAC AmpPRO behind the screen to send RCA outputs to a powered subwoofer or custom box/sub & amp.
2. Same situation as above, except you send the signal to an aftermarket amp... then cut the factory subwoofer wiring and hook it up to the aftermarket amp (this is what I'm currently doing as I didn't like losing space under the rear seats to an aftermarket sub setup).
3. (Haven't tried this myself) Same as options 1 & 2, except use a line-out converter from the 6x9 in the door to give a signal to an amp/powered sub... though you may lose some extreme low end - I haven't cared to test just how low the 6x9 signals go, but they go pretty damn low... maybe all the way to 20 Hz. With this option though you lose the ability to have non-fading subwoofer output & independent EQ of your 6x9s.

 

[odhinnhrafn]

So, possibly stupid question (I don't have the HK system). Did you turn loudness off? It amplifies bass at lower volumes.

 

[Hackmunch]

rockford dsr1 and swap factory amp. problem solved.

 

[Brewman]

I too was suffering from the overly boomy bass (have the HK system). I like more rock style music with and the bass was just giving me a headache. I finally have it somewhat under control:

1. Packed some heavy moving blankets over the sub behind the rear passenger seat
2. Set EQ to mids +5, treble +3, and bass -3.
3. Shifted fade to right +1

The padding behind the seat did help, but it was the EQ changes that really made the difference. EQ adjustment is really more about fooling the DSP than actually controlling frequency levels. Set bass too low and you lose too many low-mid frequencies. By bumping mids and highs it actually seemed to cut low frequencies.

 

[Gman]

By bumping mids and highs it actually seemed to cut low frequencies.

You're not so much de-emphasizing the bass, your emphasizing the mid and treble.

 

[392DCGC]

I too was suffering from the overly boomy bass (have the HK system). I like more rock style music with and the bass was just giving me a headache. I finally have it somewhat under control:

1. Packed some heavy moving blankets over the sub behind the rear passenger seat
2. Set EQ to mids +5, treble +3, and bass -3.
3. Shifted fade to right +1

The padding behind the seat did help, but it was the EQ changes that really made the difference. EQ adjustment is really more about fooling the DSP than actually controlling frequency levels. Set bass too low and you lose too many low-mid frequencies. By bumping mids and highs it actually seemed to cut low frequencies.

Or, fix it properly, and disconnect the factory sub from the factory amp. You can power the factory sub with your own amp and feed it an unmolested signal for proper bass response. Or, use a different sub altogether, but I haven't seen anything that wouldn't compromise on storage space other than just using the factory sub.

 

[Brewman]

[QUOTE="Gman, post: 235821, member: 344
You're not so much de-emphasizing the bass, your emphasizing the mid and treble.
[/QUOTE]
I disagree. If it were an analog system you'd be 100% correct, but as I said you're really manipulating the DSP. With mids and treble at 0 reducing bass to -9 had virtually no effect, but by raising the mid and upper frequency it seemed to cause the DSP to reduce the bass relative. Don't have any evidence other than my ears. but definitely worked to get closer to where I want it to be without the cost and unknowns of trying to go with after-market components.

 

[Brewman]

So, possibly stupid question (I don't have the HK system). Did you turn loudness off? It amplifies bass at lower volumes.

AFAIK HK sytetm doesn't have a loudness setting