Under-Seat Subwoofer Issues

[D.J.]

I’m just betting it’s more a matter of input quality & settings vs. not enough power/volume.

You might be on to something there.

 

[Aarvix]

Is there a diagram somewhere of the sound system from the head unit to each speaker? Sorry to hijack. It'd be nice if we could upgrade the amp, for instance, with something plug and play. Pipe dream, I'm sure. But overall the sound system needs just a bit more power in my ears.

The head unit sends a flat signal and CANBUS commands over SPDIF to the amplifier. All processing as well as volume control is done by the OEM amp, so replacing it isn't so simple if you wish to retain factory controls.

With that said, I just picked up an iDatalink Maestro AR which (in theory) does just that. It needs a compatible amp, which I also bought.
Stay tuned, I'll be updating my build log, but it's gonna be a few weeks (too many competing projects)

 

[Kazz]

Hello Kazz, and long time no chat. But have to admit I don’t understand what you and some others on here mean by needing more power or loudness.

Not saying it will ever be comparable to an aftermarket system with 1000s of watts & powered 10”+ subs, but with the correct settings & input, anything over volume 13-15 shakes all the mirrors and is almost deafening loud.

HK’s 720w & 15 speakers is pretty substantial for a good high end stock system and it would cost thousands more to do marginally better. I’m just betting it’s more a matter of input quality & settings vs. not enough power/volume.

Yes! Long time no chat! You have a much different system than I do then. Pixel 7 via bluetooth is what I'm using. Tough to shake much until I'm well into the 20s.

 

[Volfy]

The head unit sends a flat signal and CANBUS commands over SPDIF to the amplifier. All processing as well as volume control is done by the OEM amp, so replacing it isn't so simple if you wish to retain factory controls.

With that said, I just picked up an iDatalink Maestro AR which (in theory) does just that. It needs a compatible amp, which I also bought.
Stay tuned, I'll be updating my build log, but it's gonna be a few weeks (too many competing projects)

Do let us know how it goes. I would've gotten one, but it is listed as compatible with Harman Kardon system only, and mine is not HK.

 

[LordKOTL]

^ this ... i think they are crossed over at around 40-ish Hz, which is very low. if you want to hear them, use a music app with an adjustable EQ (i use Poweramp), and boost the low freqs (31Hz, 62Hz) and you will hear/feel them.

with that being said, i listen to mostly thrash/metal that typically doesn't get that low, so the underseat subs rarely get any work for me. i do like my bass tight and accurate, so i added a powered sub in a sealed enclosure with a higher lowpass cutoff frequency, so i get the hit from a bass drum better.

I did this today in MusicOLet; my mp3 app on my phone, which has built-in eq settings for each bluetooth device. I set up my stinger on a similar EQ curve and the sound is much better.

Now if I could only find an EQ app that works with Pandora...

 

[StungBlueGT2]

Yes! Long time no chat! You have a much different system than I do then. Pixel 7 via bluetooth is what I'm using. Tough to shake much until I'm well into the 20s.

Well technically our systems are the same since both are GT2’s with HK. So the capability is the same, however one of your biggest limitations you mentioned is the BT. Wireless data transfer restrictions & compression cause noticeable sound quality & output degradation.

Have you ever tried lossless audio or similar from a USB?

Also, are you using “On Stage” mode, with clari-fi off and at least +8 bass on eq?

 

[Landshark]

I did this today in MusicOLet; my mp3 app on my phone, which has built-in eq settings for each bluetooth device. I set up my stinger on a similar EQ curve and the sound is much better.

Now if I could only find an EQ app that works with Pandora...

that is not my EQ setting, just a random photo from the internets - that would be a bit extreme for me, but you get the idea ...

a Google search returned this ...

 

[Kazz]

Well technically our systems are the same since both are GT2’s with HK. So the capability is the same, however one of your biggest limitations you mentioned is the BT. Wireless data transfer restrictions & compression cause noticeable sound quality & output degradation.

Have you ever tried lossless audio or similar from a USB?

Also, are you using “On Stage” mode, with clari-fi off and at least +8 bass on eq?

Not yet. But I don't really have a solution for that other than perhaps one of the 'wireless usb' solutions that include an android device. Hell, I'd buy an old iPod that had enough storage for 2,000+ songs downloaded from Spotify. And yes, I'm using Spotify so not that lossless. LOL

As far as +8 bass, I've used +7 but I've currently muddied a lot of settings trying to find a better mix. I was running +2/+4/+7(8?) for a long time.

 

[LordKOTL]

that is not my EQ setting, just a random photo from the internets - that would be a bit extreme for me, but you get the idea ...

a Google search returned this ...
View attachment 80233

Well, it did work...and mine's not as extreme, but it does work.

And thanks for the suggestion; I'll check it out.

 

[socalvn]

Interesting YouTube article

 

[Onno P]

Interesting YouTube article

Hope he will post a detailed DIY….

 

[Kazz]

Took the time to try to get my music straightened out in the car. I use Spotify and a Pixel 7. The best I can do in my '18 GT2 with stock HK sound is to NOT use Spotify's EQ. Every time I've tried to use it, regardless of setting or even the variable User setting the volume drops probably close to 10 points. Meaning I have to turn the volume up to 30 to be roughly equal to the volume at 20 without Spotify's EQ. So at least the volume's figured out.

That meant it was all up to Kia's head unit to do the rest. FWIW, I'm damn old and listen to 60's through 2000's music. Lots of classic rock with a bit of Motown, R&B, occasional bluegrass-y stuff, etc. The difference between songs is sometimes pretty awful. In order to hear more modern music the way I want means I have to tweak the settings a bit when older stuff hits. By settings I mean 'Tone' in the Sound Settings menu. I fiddle with Treble and Mid right around zero and Bass is +7-8. Sometimes +8 distorts on the old stuff and I have to dial it back. Same with Mid and Treble sometimes as tracks change.

I have over 2100 songs 'Like'd on Spotify and just use Shuffle. It's like an awesome oldies station. LOL

Hope this helps someone!

EDIT: Oh! And the subs hit HARD with the right kind of music. And I agree there's a low range that is not recreated by the HK setup. If you want more rumble you have to do an add-on sub. I actually have a small powered one I might try some day.

 

[Landshark]

Hope he will post a detailed DIY….

that's a lot of work to get those tiny subs working. its a lot easier just to add an extra sub.

EDIT: Oh! And the subs hit HARD with the right kind of music. And I agree there's a low range that is not recreated by the HK setup. If you want more rumble you have to do an add-on sub. I actually have a small powered one I might try some day.

i added a powered 10" sub in a sealed enclosure - i listen to mostly thrash, metal, and rock and don't want the "boomy" bass of hip hop, etc. ... i want it tight and accurate. the remote bass level control mounted down near my right knee is a bonus - don't have to menu-dive to make a quick adjustment.

 

[socalvn]

that's a lot of work to get those tiny subs working. its a lot easier just to add an extra sub.



i added a powered 10" sub in a sealed enclosure - i listen to mostly thrash, metal, and rock and don't want the "boomy" bass of hip hop, etc. ... i want it tight and accurate. the remote bass level control mounted down near my right knee is a bonus - don't have to menu-dive to make a quick adjustment.

You got to move the remote Base Knob mine is in the center council that little bucket right by your hand at the end of the armrest it's easy to adjust it, no reaching. 12-in duel voice coil non-ported box

 

[Landshark]

You got to move the remote Base Knob mine is in the center council that little bucket right by your hand at the end of the armrest it's easy to adjust it, no reaching. 12-in duel voice coil non-ported box

mine requires LESS reaching ... its closer to the steering wheel

 

[Baconator]

y not have them at all depending o

Anyone have access to a service manual? I’d like to know where the amp is and wiring schematics for the 15 speaker Harman Kardon setup!

If you have 22+ the manual is on the infotainment.

 

[D.J.]

If you have 22+ the manual is on the infotainment.

You quoted, some of the oldest posts on the forum!!!

Nothing really wrong with that, but it is kind of comical

 

[Baconator]

You quoted, some of the oldest posts on the forum!!!

Nothing really wrong with that, but it is kind of comical

Trying to farm updoots

 

[Ah GetFd]

Who's having issues with the subwoofers under the seats? You may not have them at all depending on which options you pick - but some people who DO have them are reporting they're not feeling or hearing any bass from these speakers. The more I see people talk about it, the more I realize this is becoming a fairly popular issue.

I'd like to discuss this and get to the bottom of it. Are the speakers faulty? The wiring? Did the wiring just become disconnected along the delivery process? Were they never connected in the first place? Let's get this figured out...

It should be working like this...

Update 02.02.2018 - Possible reason "some of the subs were not activated (turned on) on the amplifier".

This is a very old post but entirely relevant as cars change hands.

I bought my two Stingers new in 2023 and had the same issues. Took the first back to the dealer the day after I bought it. Sub Woofers don't work I said. They checked another new car in the showroom. Same. You would think after 5/6 years the dealers would have had an answer.

Then googling I found the solution was the dollar bill test. The sub woofers indeed do work but only on very low bass frequencies and they do not emit any "music"

A combination of those and the regular speakers create the Bass required it was explained.

So, a loose piece of paper sat neatly on each under seat sub woofer should produce a slight vibration of the paper.

You will probably get "nothing" from regular radio and Phone Apps and only experience the subs working from USB on particular deep bass tracks.

And by the way our one and two dollars are coins. Notes went out decades ago. So a lotto ticket is ideal.