nelson29

Here's a excellent breakdown on those who wants to upgrade the factory system. Halston@BSW lists all the pros and cons of the factory system. i got this from the m5board.

http://www.m5board.com/vbulletin/e60-m5-e6...an-sweep-3.html

Enhancing bass response in these cars is complex.

The factory subwoofers are high efficiency and very low weight drivers, which means they produce high output on the modest power and dampening capability of the factory amplifier.

While it is possible to swap in another subwoofer and utilize the factory enclosure and amplifier, most aftermarket subwoofers are heavier (less efficient) and require an amplifier with more power and dampening capability. As a result, there is not currently anything on the market that not only easily bolts in but also provides a worthwhile upgrade when used with the factory amplifier.

You may have seen people replacing the factory subwoofers with the Earthquake SWS-8. We were approached by Earthquake to test the sub and found performance atrocious when used with the factory amplifier. In our view, this is simply NOT an option.

Combined with an aftermarket amplifier, the SWS-8 does provide more output, but because it's not optimized for the environment in which it plays, sound quality suffers (think "muddy" bass). In addition, the factory subwoofers are responsible for a significant portion of midbass response (they play all the way up to 500Hz, but operate primarily in the 150Hz and below range), and much of this midbass is lost when they are replaced with aftermarket woofers not designed to perform above 100Hz. (Keep in mind that just because a subwoofer can "play" a certain frequency doesn't mean that it will sound good doing it -- most commonly, subwoofers sound bad playing midbass due to poor transient response).

These results will probably be the same with almost any subwoofer you can fit in the factory under-seat locations, as subwoofer performance is driven not just by the quality of the components but, and this is the crucial point, how well matched those components are to the enclosure in which they play.

So, for those that do not want to add subwoofers and instead use the factory subwoofer locations, our recommendation is simple: add an aftermarket amplifier to power the OEM subwoofers (in Logic7 vehicles -- in Standard cars, we suggest you upgrade to the L7 woofers, then amplify them).

This can provide a wonderful sounding upgrade to the system as it maintains the matched subwoofer to the enclosure, and with more power and dampening capability, can enhance output and sound quality. In our experience, RMS wattage should not exceed 100W per woofer to insure OEM subwoofer longevity.

If you'll be adding additional subwoofers, it's important to keep the OEM subwoofers as they do provide quite a bit of midbass so completely removing them in not the best option as you will miss out on a pretty wide frequency range (as mentioned earlier). You can then add on a properly setup aftermarket subwoofer system. The advantage here is that woofer and enclosure limitations are removed, but the disadvantage is that you're unable to effectively tune a portion of the vehicle's bass response, the OEM subwoofers.

Lastly, going 100% aftermarket would be another choice, i.e. a signal summing device, new component sets, amplifier and a full subwoofer system. This would have midbass drivers playing midbass, subwoofers playing sub bass and your midrange/tweeter playing the mids and highs. This would require the most end user work but if properly setup can provide quite the upgrade. If you're willing to do the work, it'll sound the best -- but it's a LOT of work.

Moving on...

It is NOT true that an amplifier upgrade should precede a speaker upgrade in these vehicles. There are certainly some general rules and concepts that are fairly consistent in the audio world, but every vehicle has its own unique set of challenges, so it's simply not useful to say "an amplifier upgrade should always precede a speaker upgrade" or "the amplifier is always the weak link." These are generalizations that simply do not hold true in a huge number of vehicles, especially in the most recent BMWs.

Why shouldn't you replace the amplifier first in Logic7 vehicles? Simply because it's not the problem. Let me explain.

The factory Logic7 speakers in the E60 vehicles are very well constructed. In other words, the quality of materials used and they way they were built is, for once, what you'd expect in a BMW: high quality rubber surrounds, aluminum cones, nicely sized magnets, etc. So in terms of durability, they're great.

Unfortunately, while they're well-made, the way they were DESIGNED yields terrible sound quality. Why? The midranges do not use a curvilinear cone, an important tool in speaker design in order to insure flat frequency response in the "breakup" frequency range (the upper limits of where a speaker can play), ESPECIALLY when the cone material used is aluminum, which is the case in L7 cars. This yields a "choppy" frequency response curve which, to the human ear, is perceived as harshness (i.e. some sounds are too quiet, and some are too loud, rather than of equal volume). And because the speaker is played with no crossover, this choppiness is heard right where flat frequency response is most important: the midrange, like vocals, guitar, etc.

What this means for the listener is that the system, while initially impressive because it sounds very "sharp," becomes extremely fatiguing over time, tiring your ears because they are quite literally being "beaten up" by the audio system.

The same, more less, holds true with the aluminum tweeters. It's like listening to the audio system through a Coke can or something. And, the factory tweeters miss out on a wide range of sound above 12,000Hz, so little subtleties are lost -- things like twinkles, the breath of the recording artist on his or her mic, etc.

But, surprisingly, these are almost the ONLY issues with the factory Logic7 audio system. The stock amplifier makes solid power, displays good sound quality, and is in most regards a reasonable peice of equipment. And there are simply no issues with signal quality (i.e. head unit, etc.) as in a car environment the noise floor makes this almost a moot point.

For the record, we're pretty confused at the design choices made as the system is SO CLOSE to being great and as best we can tell it wouldn't have cost any more to do it right (see below). We just don't get it -- maybe this kind of sound sells more on the dealer lot or something.

So how do you fix these problems?

Simple: use fiberglass, curvilinear midrange drivers that have a smooth rolloff and reasonably flat frequency response, and combine them with silk-dome tweeters (which sound much more natural) that play more midrange (to raise the soundstage) and have a higher frequence response range than factory. The end result is a much more neutral, balanced sound that doesn't fatigue the listener and provides much more realism and detail.

What about Standard audio vehicles? The issues are much the same, only with lower-quality construction paper-cone midrange drivers and cheap, harsh tweeters. In these vehicles, our upgrade has the same effect plus added durability, but an amplifier upgrade is a more viable option since amplification in Standard audio equipped vehicles is somewhat of an issue, too.

Ghostteck

wow really good post =)

Howitzer

Good thread