Found replacements for factory HK midrange speakers

[aleksey]

Hello Everyone, I just got a 1997 M3/4 Cosmos Black with 103k miles on the clock. As usual, the front HK midranges were blown. I was looking aroung and I found that it is not too easy to find 2.5" speakers online. Then I looked at the specs of KLIPSCH PROMEDIA ULTRA 2.0 COMPUTER SPEAKERS. I found that these speakers have a total of FOUR 2.5" Klipsch drivers. I bought two such used speakers on ebay for $63 and took them apart.

I used a rough file to get rid of the mounting "ears" on the Klipsch speakers to make them round and then put them in. They fit perfectly and sound great. I am actually quite picky about the sound (I have Mirage speakers for my HT) and I think these replacements are excellent.

The HK drivers used in the BMWs are 20Watts and 3ohms, the Klipsch ones are rated at 13 watts, but their average impedance is 6 ohms, thus the current going through the speaker is approxmately halved, so effectively, with this amplifier, they can withstand higher volumes than the stock speakers. In terms of sound volume output they are much more efficient than original HK's so they output same loudness using less current. I have been using these drivers for 2 weeks now and they are alive and well.

Total time for replacing both speakers: 1.5 hours.

[JPWheelr]

your find may be neat, but your math and usage of ohms law is anything but right. I mean, you're really really really wrong.

Your volume knob may be higher, but total volume (actual) is not. In fact, you'll have to have DOUBLE the power to get the same volume result.
Welcome to the board, sorry about your bubble.

[aleksey]

Ohms law has nothing to do with how loud the speakers sound. It only has to do with voltage, current and resistance and it is not really applicable here, because we are talking about alternating current and speakers are inductive load. The speaker's effective resistance depends on the frequency and the stated resistance is just an average. I only made a ballpark computation.

As I had mentioned, there is also such thing as efficiency of the speakers, that is what portion of the input power is output as sound. The Klipsch are more efficient than HK, that is they produce louder sound at the same input power. I observe that Klipsch sound as loud as the HK speakers (not blown) on my friend's 323CIC at the same overall volume level.