How can a BMW underseat subwoofer upgrade easily improve your sound system?

You are here:
Estimated reading time: 5 min

underseat subwoofers

There are several BMW speakers brands, it all comes down to how much you
want to pay.

The BMW HiFi sound system (S676A) and low-tier base stereo both feature OEM
speakers from BMW’s partners, but don’t carry any overt branding from a known
audio name. Those two stereo options are found in more than half of all BMWs,
but the situation changes as you move up through the stereo options.

Harman Kardon BMW speakers are available in many vehicles, with the BMW/HK
partnership already well-established at this point. Whether you’re looking
for a 3 Series or an X5, you shouldn’t have any problem finding a vehicle
with HK speakers. Just keep in mind that when it comes to the full Harman
Kardon Surround Sound System, BMW limits its availability to the higher-end

Those models may also be able to choose speakers from a more prestigious
audio house, like Bang & Olufsen or Bowers & Wilkins, and as can be
expected you’d be looking at dropping some serious coin to pick up one of
those systems.

Learn more in our BMW Harman Kardon sound system review.

When it comes to the subwoofers, each stereo system includes woofers with a
resistance (ranging from 2 Ohm to 8 Ohm) that will perform well with that
system’s factory amplifier. That means you won’t get ideal performance from
swapping out your subwoofers for those from another BMW OEM system unless
you’re changing the rest of your audio hardware, too.

What size speakers are in a BMW?
Don’t believe us? You could always try that swap out; almost all modern
BMWs use standardized speaker sizes, so the speakers from all stereo options
can fit neatly in the same cavity in the interior trim.

That means each speaker type is going to have the same diameter:
Subwoofers: 255mm
Midranges: 100mm
Tweeters: 25mm
Dedicated BMW replacement speakers, like those in the Alpha One BMW sound
system upgrade, will be made to the same size with the same mounting points,
so they easily bolt in in place of the factory speakers.

Where are the speakers in a BMW?
Where you’ll find your BMW’s speakers depends both on which model you have,
and which stereo system it’s kitted out with. That shouldn’t come as any
surprise the X5 has places to put a speaker that don’t even exist in a

A more premium sound system also comes with more speakers in more places,
for a more immersive sound experience.

The BMW G20 audio system is representative of a typical kit, where a full
set of speakers may consist of:

A tweeter and midrange in the dashboard.
A tweeter and midrange in the front doors.
A midrange in the rear doors/panels/shelf possibly with tweeters.
A BMW underseat subwoofer under each front seat.
A pair of tweeters and midranges in the real shelf.

Where are the speakers in a BMW?
Larger vehicles may have speakers in the D pillars, to make sure the whole
vehicle is filled with sound. The exact location can also be a little
different; some two-seaters fit the subwoofers behind the seats, rather than
under them.

This only applies to vehicles with a higher-end stereo system. In
lower-spec vehicles, the BMW door speakers are probably going to stay, but
you’ll likely have to do without any (or as many) speakers in the dashboard
and rear shelf / D pillar positions.

That said, when buying BMW replacement speakers or getting a BMW amplifier
upgrade, you may choose to add those missing speakers, particularly if your
vehicle’s interior trim has open mounting positions for the speakers in higher-spec

So why so many speaker types? Of course each speaker is dedicated to a
particular frequency. For the best sound experience, you’re going to want to
make sure your woofers, mids and tweeters are all performing at their

It’s the subwoofers that are responsible for the most visceral sound,
though, so for many, high-quality subwoofers are the most important thing.
Particularly if you listen to bass-heavy music, you’ll want to do everything
you can to get crisp, powerful bass.

What do BMW underseat subwoofers do to your sound?

With the factory woofers, the sound can start to break down at higher
volumes, giving either distortion or an overly compressed, muddy sound. BMW
underseat subwoofer issues like that definitely aren’t what you want, which
explains why the woofers are the most popular speakers to replace

With the right BMW underseat subwoofer upgrade, you’ll get great bass on
all styles of music.

You’ll want to make sure you’re choosing the right BMW underseat subwoofer
replacement, then. That’s where the Alpha One woofers stand out, with their
careful design, great performance and perfect match for your BMW. Crafted
from premium materials and with greater power handling than the stock BMW
speakers, they’re a marked step up from the factory HiFi and Harman/Kardon
systems, and can even replace the individual audio (S752A or S6F2A) woofers
in vehicles with BMW’s top stereo offerings.

Depending on your factory-original BMW sound system or aftermarket
amplifier retrofit, you’ll want speakers with the right specifications to
match the rest of your stereo. In some cases, the best speakers are
low-resistance 2 Ohm woofers, but with some setups you’ll get better
performance from a higher-resistance speaker.

What are the best speakers for BMW?

Autosvs makes it easy, with the Alpha One subwoofers available in 2, 4 or 7
Ohm versions to match your factory amplifier or the partner Alpha One BMW
amplifier upgrade. Just select your factory stereo or even easier, your VIN
and Autosvs will offer the perfect subwoofer for you. That way, you can be
sure you’re getting the best bass response from your setup.

Learn what to upgrade first BMW speakers or an amplifier?

As they are made specifically for BMWs and MINIs, and use the same
dimensions and mounting positions, switching out your factory BMW speakers is
simple. In most cases you only need to.

Gain access to the speaker (you might need to pry off a few interior trim
Unscrew the factory speaker.
Unplug the audio in/out cables (no cable-cutting required).
Plug your BMW replacement speakers into the same wires (the Alpha One
speakers come with matching plugs).
Screw your new speakers back in place, using the same holes the original
were mounted to.
That makes for an easy, DIY installation process, and it’s completely
reversible if you ever want to move your aftermarket speakers over to a new
vehicle. Just do the same in reverse, and your OEM speakers will be back like
nothing ever happened. Or if you know there’s no going back, your stock
speakers will come out in mint condition, so you can even sell them to help
fund your new and improved audio setup ūüėČ

How to disconnect underseat subwoofer BMW
When swapping out your BMW underseat subwoofers, there may be one extra
step compared to the standard process outlined above.

In some BMWs, the factory subwoofers are glued in place, rather than
screwed. In that case, after moving your front seats to get to the woofers,
you’ll need to pry them loose from the enclosures.

With that done, you can easily unplug them, slip the replacements into
place and screw them in. The Alpha One A90 subwoofers come with the required
mounting fixtures, so you’ll have everything you need to get your new woofers
set up.

If you aren’t sure whether your subs will need ungluing (for something like
the BMW F30 underseat subwoofer, it can depend on your vehicle
configuration), get in touch with our team for help.

Of course, the story doesn’t end with great BMW replacement speakers. You
might get better, clearer bass after a BMW underseat subwoofer upgrade, but
your sound is still likely to be limited by what your BMW’s amplifier is
capable of putting out, which is just one of the reasons why it’s worth
upgrading your BMW amplifier.

With the right amplifier, you can go further fine-tuning your audio, to
produce stronger bass along with better performance in the higher

The Alpha One amplifier by Autosvs is made to match either the stock BMW
speakers, or the Alpha One replacement speakers for BMW. With its 64-bit DSP
that comes custom tuned for your BMW model and musical preferences, you’re
guaranteed amazing sound out of the box. Like the Alpha One speakers, it’s
BMW specific, so installation is quick and easy. And with Autosvs’s expert
team ready to help, you know you’re going to get the sound you’ve been
dreaming about.

Was this article helpful?
Dislike 0
Views: 4
Previous: BMW’s Head-Up Display: A Genuine Safety Feature Or A Passing Fad?
Next: BMW Remote Start – Get Ready to Take Off