01 325i business cd system

[Xaximus]

Recently purchased my bimmer and looking to replace the blown 5 1/4" front door speakers. I visited a car stereo dealer and he basically said I have to replace it with a factory speaker because the ohms are matched for the business cd factory amplified system. Replacement speakers wouldn't work. I need a little direction. I've got a 10 speaker setup but only 8 are active. The small ones on the front corner window frame don't work or aren't installed.

[DennisCooper]

Hi,

There are correctly impedance matched, direct fit drop in replacements available from BSW, Hertz, Rainbow, MB Quart, Gladen brands for the E46.

You'll need to get a set of these brands product options for your car. They're more expensive for sure but the only choices if you wish to retain the rest of the OEM audio setup.

Cheers, Dennis!

[MarcoZandrini]

Impedance matching is overrated, IMHO. We have to realize that the speaker's resistance, measured in ohms with an ohm meter, isn't a true representation of the speaker's impedance. Why? A speaker has a coil through which the "music flows." Music typically contains multiple frequencies. As a result, the coil's actual impedance changes with the changes in the audio input.

JMHO

[bobdavisnpf]

I think the 01 325i Business CD HU is also known as the CD43. My CD43 says "BMW BUSINESS CD" on its face plate - the "near-stock look" is a major factor in its popularity as an E30 upgrade.

I pulled the factory radio, amp, and 8 ohm speakers - replaced with CD43, new HU-to-speaker wiring, and JBL 3 ohm speakers all around. Works great.
I tested with 8 ohm fronts and 3 ohm rears on the old HU/amp and factory speaker wiring, that worked fine too.
I ran a month or so with 8 ohm fronts and 3 ohm rears on the CD43 and factory speaker wiring, that worked fine too.

So, yeah, what Marco said. Impedance matching is good - I'll always impedance-match R/L speaker pairs - but it's typically not a "blows up if mismatched" thing.

fwiw I contacted JBL's tech support and asked specifically about matching their 3 ohm speakers to the CD43 which typically uses 8 ohm speakers, providing very detailed plans prior to hookup. Their escalation engineers were careful not to say "this will always work" but said nothing to discourage me from trying it out. They market the 3 ohm speakers as factory-replacement systems, arguing that the undersized and over-long speaker wire routing in most cars suffers an impedance drop that their lower-impedance speakers can help make up for.

[MarcoZandrini]

OP, go to www.critchfield.com to see what fits. Develop a budget, and then start looking for the speakers. Be advised that you cargas an 8 or 10 channel amp in the trunk. Tre amp has built in crossovers.

- - - Updated - - -

Should be www.crutchfield.com.