Trying to disconnect HK subwoofer w/o success: what am I doing wrong?

[scottmoyer]

Question for you guys doing this. I'm not an audiophile and don't understand all of the tech associated with quality audio. When having the sub connected, are all the low frequencies directed to the sub, and disconnecting the sub will allow the low frequencies to be directed to each speaker? Are the HK speakers 3 way? My concern with disconnecting the sub is that the mids and highs will be played and there won't be much low based on speaker design.

What are you guys noticing?

 

[Tydog96]

I might try it, after some other "retired" goals ease off However, I had just dropped it very low in the EQ and have been very happy with the SQ. I did replace the two front corners with the Infinity tweets. I listen primary to mixture of Iphone, and SiriusXM. (70-80s Rock and Country). You don't have to pull the backseat to disconnect do you?

 

[HAL9001]

As an alternative to disconnecting the subwoofer altogether, stuff the enclosure with poly-fil. Then, stuff more poly-fill in front of the subwoofer wedged between the back seat. This mutes the subwoofer dramatically yet still allows the deeper notes to play through it. For those who like bass, this gives better bass performance than just using the door speakers, yet it effectively mutes the subwoofer so it's no longer boomy, more in line with what it should have been.

After doing this, I now thoroughly enjoy my HK system, it sounds incredible.

 

[Swicago]

You say the sub booms on every not you believe it shouldn't. Maybe pull the sub and check if it has a proper low pass filter or swap one in that is lower. Most likely the sub is reacting to all notes lower than say 400hz, maybe swap in a low pass that does 100hz or lower. Then it will only react to really low notes and not all low notes.
Someone mentioned wanting to limit volume. If the sub gets non digital audio signal from headunit, then a simple knob style resister can work to reduce volume before it gets to the subs amp(think like a gain). If the signal is digital, then you would need one of those old school speaker volume control, that can handle the wattage on the output side of the amp. Both wouldn't require much work.

 

[HAL9001]

You say the sub booms on every not you believe it shouldn't. Maybe pull the sub and check if it has a proper low pass filter or swap one in that is lower. Most likely the sub is reacting to all notes lower than say 400hz, maybe swap in a low pass that does 100hz or lower. Then it will only react to really low notes and not all low notes.
Someone mentioned wanting to limit volume. If the sub gets non digital audio signal from headunit, then a simple knob style resister can work to reduce volume before it gets to the subs amp(think like a gain). If the signal is digital, then you would need one of those old school speaker volume control, that can handle the wattage on the output side of the amp. Both wouldn't require much work.

My guess is that the low pass filtering is being done by the amplifier, not discretely. I was going to add an L-Pad attenuator as you suggest but I thought I'd first try simply attenuating it via poly-fil which did the job to my satisfaction. I didn't want to just disconnect it as others do because I appreciate very deep bass that only a subwoofer can provide.

 

[Swicago]

My guess is that the low pass filtering is being done by the amplifier, not discretely. I was going to add an L-Pad attenuator as you suggest but I thought I'd first try simply attenuating it via poly-fil which did the job to my satisfaction. I didn't want to just disconnect it as others do because I appreciate very deep bass that only a subwoofer can provide.

Even if the amp is filtering, you can add another even lower pass old school style filter directly to the speaker. Just have to open it up.

 

[dsmonline]

I disconnected the sub after my drive home from the dealer (all of 5 miles), no way I was going to put up with that terrible bass. Took about 15 to 20 minutes start to finish, not at all difficult to do. Hardest part was finding the seat back release cord to pull so I could lean the seat forward. I have never thought I might want to hook it back up.

 

[Buz]

And because it's not a safety issue, FCA is not going to spend $1 on fixing it and getting out an update.
The Alpine system is the best system in this current model lineup.

 

[beanz690]

Great thread going on here thanks to all for sharing. I have been thinking about doing something to resolve the annoying boomy subwoofer but I really enjoy deep bass and don't want to be without the ANC since I have a loud exhaust and have heard people complaining about the lack of ANC.

I had an idea but not sure if this could work. Would it be possible to disconnect only the audio signal from the radio to the subwoofer but allow the ANC mic signal to continue as normal? This way I can just add an aftermarket subwoofer down the line but have the ANC functioning 100%.

 

[thedream829]

I unplugged the subwoofer and I don't miss it at all. I now turn the bass to +5 and it's A LOT better.

 

[thedream829]

Great thread going on here thanks to all for sharing. I have been thinking about doing something to resolve the annoying boomy subwoofer but I really enjoy deep bass and don't want to be without the ANC since I have a loud exhaust and have heard people complaining about the lack of ANC.

I had an idea but not sure if this could work. Would it be possible to disconnect only the audio signal from the radio to the subwoofer but allow the ANC mic signal to continue as normal? This way I can just add an aftermarket subwoofer down the line but have the ANC functioning 100%.

I didn't know the Active Noise Control was deactivated if you unplug the subwoofer. I didn't notice a difference.

 

[Nsm42]

I unplugged mine about 2 weeks ago and I’m actually missing the extra bass! Contemplating going back but I do appreciate the clearer miss and highs.

 

[thedream829]

I unplugged mine about 2 weeks ago and I’m actually missing the extra bass! Contemplating going back but I do appreciate the clearer miss and highs.

Did you turn the bass up in the settings menu after? It still booms pretty hard.

 

[Nsm42]

Did you turn the bass up in the settings menu after? It still booms pretty hard.

I did. I adjusted the 3 band to 8-3-2 which sounds great but I’m just missing that extra low end from the back. Maybe because I’m so used to using surround mode. I’ve been testing with it off, maybe I’ll give it longer.

 

[beanz690]

I didn't know the Active Noise Control was deactivated if you unplug the subwoofer. I didn't notice a difference.

I guess I will give it a try as well. I really want to upgrade to an aftermarket subwoofer but I didn't want to be without ANC since I have an aftermarket exhaust and don't want unnecessary noise in the cabin when cruising.

 

[dsmonline]

I am confused, if you disconnect the sub‘s connector at the sub, that will disable the ANC? The wiring diagram does not show that.

 

[thedream829]

I did. I adjusted the 3 band to 8-3-2 which sounds great but I’m just missing that extra low end from the back. Maybe because I’m so used to using surround mode. I’ve been testing with it off, maybe I’ll give it longer.

Change it so that the sound goes to the back more.

 

[beanz690]

I am confused, if you disconnect the sub‘s connector at the sub, that will disable the ANC? The wiring diagram does not show that.

No ir does not deactivate the ANC, however you lose the sub which also helps to cancel out low end noise. Other members of this forum reported hearing more engine and exhaust noise after unplugging the factory sub. That’s why I was hoping there was a way to disconnect only the audio (music/radio) signal to the factory sub to leave the ANC fully functional.

 

[dsmonline]

That makes sense, thank you for the clarification.

 

[Johnny_H]

Hey just wanted to share a few thoughts on this. I unplugged the sub this morning on my 21 Iimited. Even at bass at -5 was giving me a headache…especially since my 3yo is now into Rhianna.

I tested a few different things and at the end of the day I just left it unplugged. It’s now lacking a bit of mid range bass but it does indeed sound far better with the bass setting maxed. I think the culprit is very weak 6x9s and I’m likely going to bite the bullet and replace those. It now sounds much closer to the “base” HK system in our X5. I think the 3.5s do most of the heavy lifting in these systems, did Ram just put a sub in to compensate for crappy 6x9s?

I also plugged the sub back in and removed it from the enclosure and noticed all the boom was gone. It actually sounded real good plugged in and just lying on the back floor - as soon as you stuff it in the box it booms. I think the problem overall with this system is a shi tty plastic sub box. Unfortunately there’s no room to just “leave it hanging” without rattling or screwing up the back panel. I tried stuffing the box with towels and also tried leaving it loose but the boom remained. I honestly think a good custom wood box under the seat like the gen 4 would help a lot. I’m terrible with car audio so I’m probably just going to leave it unplugged and hope to get better mid bass from upgraded 6x9s

Finally, here’s some tips for guys wanting to do a simple unplug with a couple pics as I encountered a few differences from the experiences above.

For the 21 it’s pretty easy. Find the seat back string and pull (come at it from the middle seat with the back pulled down) and remove one single grommet. Also sliding the seat forward (recline position) gives you a few extra inches to work.

Pull hard on the back lining from the C pillar as mentioned by the OP. The wire is now contained within the white harness and you need to unsnap it. Everything goes back easy. Of note see the air pressure flaps that cause some peoples trucks to boom at certain speeds.

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