E82 1-series coupe base Stereo upgrades

Stock system overview

The E82 coupe was introduced into the US starting in the 2008 model year. It will be replaced in 2012 by the F22 1-series.

In model year 2010 and the first part of 2011, BMW replaced the HiFi system in the US – long the entry-level US audio system – with the base Stereo system. While available in the rest of the world for years, the US market hadn’t seen this sort of low-end audio system since the early E30 3-series. Many BMW owners were unpleasantly surprised by the base Stereo system’s poor performance. It can be found in vehicles equipped with either the iDrive in-dash system or with the Professional CD head unit.

The 1-series base Stereo audio system has a number of shortcomings:

- missing tweeters (no grilles inboard of the side mirrors)

- missing 8″ woofers underseat (instead, there are 6″ speakers in 8″ frames)

- missing amplifier – the speakers are driven just by the 16 watts in the head unit

- poor-performing 4″ mids front and rear

- overprocessed signals to attempt to compensate for the above problems

When upgrading this system, the last item is the most important -the overprocessed signals. Below is a screenshot of an audio analyzer measuring the electrical output of the BMW head unit in a base Stereo configuration. We were playing a pink noise test CD track – pink noise has equal energy at every octave of sound, so we should have seen a flat line across the screen. Instead, we got this:

Base Stereo electrical frequency response

The most important thing is correcting this signal, or “normalizing” it. Sending this signal to good speakers will sound horrid – screechy and boomy. If we can optimize the signal for our new speakers and the cabin acoustics of the 1-series, that’s great, but we don’t have to – unfortunately, the “normalization” is required, or we are wasting our money on good speakers and amplification to drive them.

All of our systems for the 1-series with base Stereo correct this signal. Once we have a normal signal, we can get great results with the right speakers, and an amplifier to power them.

For ordering information and pricing on these systems, please email us with this information:

- vehicle model year
- model (128, 135)
- body style (i.e., coupe or sedan)
- which BMW audio system you have
- If your vehicle is pre-2010, please let us know if you have Sirius SAT radio (helps us with part location options)



Level One

This system gives us better dynamics, in that the system sounds good even during loud passages, and has more usable volume. We also get lower lows, clear vocals, and higher highs. We add an amplifier for the all-important front speakers and underseat woofers, and we upgrade all of those. (We don’t spend budget on upgrading the rears, because we get the most return on our investment by upgrading the fronts and underseats. This is due to how our ears hear sound from in front of us best of all, and how stereo recordings are engineered to work by most recording engineers.)

Our systems are designed to install without vehicle modification, and to be removable in future if you’d like to return the vehicle to stock. We provide tech support during the installation by appointment, and we also can help find a qualified local shop for the installation if you’d like to have it done, and are outside the Portland area.

The Level One system includes:

- A plug-in interface harness to bring signal to the new amplifier, and deliver signal to the speakers – all without any cutting of wires!

- A correcting processor to give us a normalized signal to our new amplifier, which fits under the trunk trim

- A micro-size amplifier with 300 watts which fits under the trunk trim

- Upgraded underseat 8″ woofers with bolt-in adapter rings and gaskets, and plug-in wire harnesses

- Upgraded front 4″ midrange drivers with bolt-in and plug-in adapters

- Upgraded 20mm silk-dome tweeters mounted in BMW trim pieces, with integrated crossovers and plug-in adapters

- All power wiring, speaker wiring, parts, and adapters needed to install this system

There are some “a la carte” upgrades available to this system – contact us for details or to place an order.



Level Two

With Level Two, we are using higher-performance midrange and tweeter speakers, as well as more powerful DSP signal tuning. The tweeters are 28mm units which are the largest-piston tweeter units that can fit into the BMW tweeter trim. The 4″ mids have the largest cone of any 4″ midrange, and their 2″ voice-coil motor winding allows the amplifier to have more precision control of the motion of the cone. The result is warmer midrange and more liquid sound from vocals and strings, at any respectable volume.

We are also using audiophile amplifiers with DSP processing built in. We use the DSP section to both “normalize” or counteract the stock signal, and optimize it for the speakers used. To fit the two stereo amplifiers, we use the European CD changer trim panel for the driver’s side of the trunk. This way, no external normalizing processor is needed – and we get the benefits of tuning the system for the cabin acoustics of the vehicle.

The Level Two package includes:

- A plug-in interface harness to bring signal to the new amplifiers, and deliver signal to the speakers – all without any cutting of wires!

- Two DSP-enabled, fan-cooled amplifiers

- Upgraded underseat 8″ woofers with bolt-in adapter rings and gaskets, and plug-in wire harnesses

- Upgraded audiophile-grade front 4″ midrange drivers with bolt-in and plug-in adapters

- Upgraded 28mm silk-dome tweeters mounted in BMW trim pieces, with plug-in adapters

- All power wiring, speaker wiring, parts, and adapters needed to install this system (except the trunk trim panel, see below)

(NOTE: Due to the cost of shipping the large trunk trim panel, we supply the BMW PN and recommend sourcing from your local dealer – who doesn’t have to charge you for shipping.)

There are some “a la carte” upgrades available to the system – contact us for details or to place an order.



Level Three

With Level Three, we use a standalone DSP processor to both “normalize” that signal and to “optimize” the signal for the cabin and the speakers used. We then feed that signal to audiophile-grade amplifiers, concealed under the Euro CD Changer cover trim. There are a few different configurations, with and without trunk sub-bass modules. Please contact us for details on Level Three.