BMW G6x / i5 audio options and base audio upgrade

17.3.2026

In this article we go through all the available factory audio options that you can get for G60 and G61 (also G90/G91 M5) and how to upgrade starting with base audio. Later blogs will be about Harman Kardon and Bowers & Wilkins upgrades. These instructions and examples includes all gasoline/diesel/hybrid and full electric i5 as chassis are same in all.

There are slight differences in B&W audio option regarding trunk subwoofer enclosure and it's location at least between ICE and EV touring models. Also looking at parts catalog some early G60 gasoline cars still have underseat subs at least on base audio option. But mostly G6x uses double 50x80mm door woofers.

Regarding 4" speakers and tweeters that are used in doors, center, rear shelf or roof there are no space (height) limitations when selecting aftermarket speakers like i4 has. Just make sure midrange chassis is right for example doors have mounting holes wider apart compared to center speaker and usually all aftermarket speakers have those two options.

Base Audio

Base audio comes when you don't choose any audio option and there is no code for audio in equipment list (VO). There is 7-channel RAM amplifier (Receiver Audio Module) in left side of trunk, but only 6 channels are used and no wiring for 7th meaning no center speaker. Front doors have 4" 8 ohm midrange speakers and same ones are in rear doors in touring and back shelf in sedan.

Biggest problem about sound clarity is lack of tweeters. There are places for them inside door panels, but no grilles just blank cover plates. Adding aftermarket component speakers new grilles are needed and seems that G6x doesn't have HiFi 676 option so need to buy 674 Harman Kardon grilles from dealer. There are several color options depending interior and part numbers can be found from Realoem.com part number 6.

About woofers it is a bit unclear which models regarding drivetrain have underseat or door woofers. At least i5 uses double 50x80mm door woofers that are in sealed box bolted to doors. That is simply because there is no room for underseat woofers cos' of HV battery. Impedance is most likely 4 ohm and currently there are no aftermarket options available.

Looking at parts catalog some gasoline cars still have underseat woofers similar to older models and there are plenty of aftermarket upgrade options. As RAM-amp is same as HiFi 676/674 2 ohm woofers will work and gets more power from amp.

Harman Kardon S674

This option is just HK branded Hifi 676 and most common as extra cost only about +600€ when opted. It has same 7ch 205W RAM-amp as base audio (different coding) with added center speaker and small 15mm tweeters all around. Speakers are low quality not Harman Kardon only smaller impedance to get more power from amp; mid+tweeters 4ohm and door woofers 2ohm. No subwoofer in trunk all bass is coming from double 50x80mm door woofers.

Only thing that remotely makes this option Harman Kardon is surround button iDrive sound menu that gives you more all around sound, but no equalizer for example that HK usually has in older/other models.

Double "balanced" 50x80mm door woofers

S674 Harman Kardon OE component speakers front & center

Bowers & Wilking S6F4

This system is a mix of Harman Kardon and B&W. It comes with more powerfull 7ch RAM-amp with Harman's Logic 7 software so you can adjust surround mode intensity as 674 HK just has on/off. Also there is 7-band equalizer to fine tune sound for your liking. In amplifier department there is added 4ch Booster amp for door woofers and subwoofer in trunk. Door woofer enclosures are more sturdier than base/HK and speakers have better power handling. Subwoofer is 8" in low quality plastic enclosure and has 2x8ohm voice coils. Door woofers are also 8ohm. Total amp power is 655W.

Note: G60 ICE cars probably have two 8" underseat subs without trunk sub, but at least G61 diesel has trunk sub that is bit different than i5.

4" component speakers are located in front/rear doors, center and rear shelf or trunk roof liner depending if touring or sedan. Tweeters are 25mm aluminium dome ones same that are used in older/other models in Harman Kardon. 4" mids are B&W "Continuum" cone that really feels like thin plastic but allows led light shine through rear speakers.

OE "Continuum" cone speakers and bulkier door woofer enclosure

G61 diesel B&W trunk sub

G61 i5 B&W trunk sub

Base Audio Upgrade

Base audio is rare as Harman Kardon is low cost option when buying new car so most people opt that. We had a chance to upgrade one i5 G60 that was imported used from Germany with base audio.

For component speaker set with separate tweeter first thing that we did was order HK tweeter grilles from local BMW dealer and in this case part numbers were 51415A51C5 and 51415A51C6 (Trim tweeter front schwartz).

This upgrade was done budged friendly regarding speakers as much parts are needed and set includes:

Front speakers: Match UP C42BMW-FRT.2
Rear speakers: Match UP X4BMW-FRT.2
Amp & Harness: Match UP 8DSP + PP-BMW 1.7RAM UP 8DSP harness + URC.1 remote
Subwoofer: Helix K 10SE.2 (2+2ohm coils for UP8 bass channels, discontinued but many good 2+2ohm subs in Helix IK series for example IK E10.1-DVC2 that would fit under trunks cover)

Front door speakers

Next step is to remove front door panel. There are just 2 screws then just pop out using pry tool starting from bottom. Plastic trim at the corner needs to be removed also and when panel is free from clips lifting it up releases it from door. First pic is fake tweeter cover without holes.

There are one electrical connector and door handle latch that needs to be unplugged.

Next we need to remove tweeter cover panel by drilling melted plastic rivets out and install new one using hot glue. Then install tweeter to it's place. In this part you need to be very careful not to break clips that hold the tweeter. If that happens hot glue is needed.

Midrange speaker is mostly plug and play, but depending speaker brand external crossover box needs to be secured like with these Match component speakers. Then just install door panel back in reverse order.

Rear door speakers

As base audio doesn't have rear tweeter places it's best just upgrade with coaxials that have integrated tweeters on top of midrange.

Remove four T20 screws, lift door panel upwards and out, remove electric connector and door latch, take door panel out and replace the speaker. Then put door panel back in reverse order.

Amplifier & sub

As base audio has 6 channels good option would be Match UP 6DSP with PP-BMW 1.7RAM UP 6/8DSP harness. That is if no subwoofer is installed or sub is active with integrated amp.

In this case we went for Match UP 8DSP so that 2x160W bass channels powers Helix K 10SE.2 passive sub with 2+2ohm voice coils and combined power handling of 300Wrms/600Wmax. That maches well for bass channels output. But as that sub is discontinued good option would be Helix IK E10.1 DVC that has same power handling and would fit in storage compartment under trunk cover. This sub was not yet available when install was done.

Like in all iDrive 7 and newer stock amp cannot be replaced in so new amp is connected parallel to stock amp using hi-level inputs. Match PP-BMW 1.7RAM UP 6/8DSP harness does just that and is plug&play, except it doesn't have power and ground. Also in this case some modification was needed to switch door woofer outputs to regular 65W channels as Match UP 8DSP's bass channels were used to power subwoofer.

12V can be taken behind trunks right side fuse box when main power cable comes from 12V battery under the hood. There are also 12V outlets that can be used also and much easier way just needs specific connector for that.

Rear fuse box removed and 12V connected.