[xnick101]

Has anyone added more bass to the Harmon Kardon system? By that, I do not mean adding actual subwoofers in the trunk. I mean changing out the speakers or the under-seat subs. The bass is pretty underwhelming, to say the least. I expected more from it. If anyone has added any speakers to really bring out the bass please comment below.

[nearwater4me]

For a moderate increase in bass, you could use the Technic PNP harness to power a set of aftermarket USWs.

[latexyankee]

How can I incorporate this harness to add a small trunk sub? I have a low profile 10' shallow enclosure sub just laying around and Id like to install it in the trunk, im not great with car audio although Ive wired up a sub years and years ago.

The HK amp has 10 channels but only 9 are used? IS there a guide anywhere when adding an aftermarket sub to the HK system? The sub states 500w RMS but Id be happy with even half of that, can buy a cheapo amp if needed, battery is already in trunk, just dont know how to incorporate the harness.

[Technic]

Originally Posted by xnick101

Has anyone added more bass to the Harmon Kardon system? By that, I do not mean adding actual subwoofers in the trunk. I mean changing out the speakers or the under-seat subs. The bass is pretty underwhelming, to say the least. I expected more from it. If anyone has added any speakers to really bring out the bass please comment below.

We suggest powering the OEM woofers with a Soundstream Reserve RS2.1200 2-ch amp ($150 at Crutchfield), with a Wavtech Link2 LOC ($70 at Crutchfield) for a low cost bass upgrade for a HK system. The Bass Boost feature of this amp can get a deeper and louder bass from the OEM woofers without the need of replacing them.

If you are not satisfied with the extra bass of this aftermarket amp setup then replace the OEM woofers with SWS-8Xi and the Soundstream amp.

[viciousmo]

Originally Posted by Technic

We suggest powering the OEM woofers with a Soundstream Reserve RS2.1200 2-ch amp ($150 at Crutchfield), with a Wavtech Link2 LOC ($70 at Crutchfield) for a low cost bass upgrade for a HK system. The Bass Boost feature of this amp can get a deeper and louder bass from the OEM woofers without the need of replacing them.

If you are not satisfied with the extra bass of this aftermarket amp setup then replace the OEM woofers with SWS-8Xi and the Soundstream amp.

This will work for H/K setups? I have the BavSound ghost subs and I am wanting more bass without adding an external sub in the trunk.

[Technic]

Originally Posted by viciousmo

This will work for H/K setups? I have the BavSound ghost subs and I am wanting more bass without adding an external sub in the trunk.

This thread is about the HK system.

[Jason99GSX]

Originally Posted by Technic

This thread is about the HK system.

Do you guys have a harness to be able to add and aftermarket subwoofer in the trunk?

[Soul_Glo]

Originally Posted by Technic

We suggest powering the OEM woofers with a Soundstream Reserve RS2.1200 2-ch amp ($150 at Crutchfield), with a Wavtech Link2 LOC ($70 at Crutchfield) for a low cost bass upgrade for a HK system. The Bass Boost feature of this amp can get a deeper and louder bass from the OEM woofers without the need of replacing them.

If you are not satisfied with the extra bass of this aftermarket amp setup then replace the OEM woofers with SWS-8Xi and the Soundstream amp.

Welcome back Elias.
The man, the myth, the legend..

[Soul_Glo]

Originally Posted by Jason99GSX

Do you guys have a harness to be able to add and aftermarket subwoofer in the trunk?

The Technic PnP harness does it all bud.
You can amplify the under seats, add a trunk woofer.. different harnesses out there if you don't have HK.

[Jason99GSX]

Originally Posted by Soul_Glo

The Technic PnP harness does it all bud.
You can amplify the under seats, add a trunk woofer.. different harnesses out there if you don't have HK.

Awesome! Do you use it currently? I want to throw my sub in the trunk but wasn’t sure what harness to go with, the ones listed on their website don’t mention the HK system so I wasn’t sure!

[Soul_Glo]

Originally Posted by Jason99GSX

Awesome! Do you use it currently? I want to throw my sub in the trunk but wasn't sure what harness to go with, the ones listed on their website don't mention the HK system so I wasn't sure!

Yes I do. I replaced the under seat woofers and amplified them using his harness. Needed the trunk space so no trunk woofer. I have HK.


HK is also referred to as Top Hi-Fi (Option 688). So that would be the one to go for.

[Jason99GSX]

Originally Posted by Soul_Glo

Yes I do. I replaced the under seat woofers and amplified them using his harness. Needed the trunk space so no trunk woofer. I have HK.


HK is also referred to as Top Hi-Fi (Option 688). So that would be the one to go for.

Thankyou I appreciate the help!

[Soul_Glo]

Billfitz has dropped many a knowledge bomb on here so I have much respect for him educating us all. Whatever your upgrade it would be worth your time reading up his posts on Hoffman's Iron Law.

Looking forward to photos of your build.

[rmedina]

Hey guys, I appreciate everyone's input. I have a 2023 coming in hopefully this week. Like you I gotta have more bass. I did a custom job on my vette. Made my own fiberglass box and whole works.

My only concern with the HK upgrade. The crossover? Example my vette has a pioneer hu and I have the capability of changing the crossover levels from the hu. How would I go about this issue. I'm always changing the levels depending what music I'm listening to.

[psaav]

Originally Posted by Soul_Glo

Yes I do. I replaced the under seat woofers and amplified them using his harness. Needed the trunk space so no trunk woofer. I have HK.


HK is also referred to as Top Hi-Fi (Option 688). So that would be the one to go for.

Do you happen to have a step by step on installation and plug-in of that harness for the underseat woofers?

[Soul_Glo]

Originally Posted by psaav

Do you happen to have a step by step on installation and plug-in of that harness for the underseat woofers?

I am afraid not. I lost all my photos with an iCloud error. When I purchased the harness he sent me a PDF on wiring options. For example, how to connect an aftermarket amp. The rest is simple trim removal and wiring. There are plenty of guides on here of installs on other series. The under seat guides are pretty much all the same. Loads of videos too on how to loosen the seats and remove speakers etc.

[Soul_Glo]

Originally Posted by rmedina

Hey guys, I appreciate everyone's input. I have a 2023 coming in hopefully this week. Like you I gotta have more bass. I did a custom job on my vette. Made my own fiberglass box and whole works.

My only concern with the HK upgrade. The crossover? Example my vette has a pioneer hu and I have the capability of changing the crossover levels from the hu. How would I go about this issue. I'm always changing the levels depending what music I'm listening to.

The HK has an EQ on the iDrive which is a start. An aftermarket amp is probably best for setting up cross overs for certain speakers. Better yet a DSP for full control but there are not many you can adjust on the fly. I think with the Audison you can. There is a plug in remote to select different profiles.

[kapa1122]

Hey, been following this post and I ended up swapping the woofers with sws-8xi. Two things popped up after the install.

1.The mids and tweeters now sound muffled. Doea anyone know why this would happen after unhooking the underseat woofers?

2. When I get out of the car and shut the engine off, there is a loud increasing bass Humm that seems to happen through the new woofers. Like a 40hz tone that starts at a low volume then eventually turns up louder. Happens for about 20-30 seconds until the amp finally turns off.

I'm using the LOC with audio sensing for the remote on wire to the amp. Do you think I should use another signal for the switched 12v?

2023 m340 with HK and using a wavtech 2ch LOC and technic pnp harness.

[Technic]

1. Mid/tweeters are powered by a separate amp from the woofers in the HK system -RAM power mids/tweeters, Booster power woofers. Wherever the muffled sound is coming from is not from the woofers.

2. WavTech Link2 turns on/off with the OEM Booster - Booster on/Link2 on, Booster off/Link2 off. Booster will turn off 2-8 minutes after engine off/all doors and trunk closed. Whatever noise is coming from the Booster when car is off is amplified by the gain on the aftermarket amp. Either reduce gain, or set Link2 to turn on/off with engine - 12V switched line is required.

Originally Posted by kapa1122

Hey, been following this post and I ended up swapping the woofers with sws-8xi. Two things popped up after the install.

1.The mids and tweeters now sound muffled. Doea anyone know why this would happen after unhooking the underseat woofers?

2. When I get out of the car and shut the engine off, there is a loud increasing bass Humm that seems to happen through the new woofers. Like a 40hz tone that starts at a low volume then eventually turns up louder. Happens for about 20-30 seconds until the amp finally turns off.

I'm using the LOC with audio sensing for the remote on wire to the amp. Do you think I should use another signal for the switched 12v?

2023 m340 with HK and using a wavtech 2ch LOC and technic pnp harness.

[Steadyhand]

Question regarding the 8-ohm HK under seat subs...if I use the Technic harness (add a sub) and choose to run an external amp for the two under seat subs, how do I power those subs with 8-ohms? (assuming most, if not all amps run between 1-4 ohm)

[Technic]

Originally Posted by Steadyhand

Question regarding the 8-ohm HK under seat subs...if I use the Technic harness (add a sub) and choose to run an external amp for the two under seat subs, how do I power those subs with 8-ohms? (assuming most, if not all amps run between 1-4 ohm)

8ohms means less max power than what the aftermarket amp outputs are rated, i.e. if the output is 150W max at 4ohms then technically it should be 75w max at 8ohms. However, most aftermarket amps may output more than half its max power at 8ohms as its circuitry may adapt to changing resistance.

[Marc R]

How does one add a custom sub in the trunk togehter with Match 10 DSP?