My new amplifier upgrade

[GreyM340i]

Just wanted to update this post with my next upgrade while searching for better sound in my M3. Just got my new 6.5” Morel Virtus Nano Carbon 62 speakers. Super unique with the unbelievably thin woofers. Will be installing this weekend so I hope it’s a good upgrade over my 5-1/4” Bavsound door speakers.

[maw1124]

LMK how that install goes. I may use a pair for these fronts, but more likely for another car.

Cheers,

maw

[I M Legend]

Just wanted to update this post with my next upgrade while searching for better sound in my M3. Just got my new 6.5” Morel Virtus Nano Carbon 62 speakers. Super unique with the unbelievably thin woofers. Will be installing this weekend so I hope it’s a good upgrade over my 5-1/4” Bavsound door speakers.

Any update? How do the new speakers sound?

[GreyM340i]

Any update? How do the new speakers sound?

It’s been great so far however I need a little more DSP tuning. I might take it to a local place to have a pro tune it with a microphone. I also purchased the matching mid driver so it will be a true 3 way setup like the stock system.

[ugaexploder]

I was looking into this Audiotec Fischer Match UP 7 BMW amp and noticed that it can be installed on many different BMW platforms such as F30, E90, G01, etc...since I guess most N/A cars are equipped with Hi-Fi stereo as standard. I was wondering, has anyone considered trying an amplifier from some of the later model cars to see if it's better than the Hi-Fi amp in the E46?

[Markbo925]

Hi All, I’m going to try and revive this thread as it’s now 2026; and my HK amp has died on the passenger channels. It started as a cracking popping sound like an aux cord being adjusted. To now the passenger speakers no longer are receiving voltage. I have also confirmed there is no break in the wires.

My question has anyone tried amps from other newer chassis codes. Or on eBay do I have to replace with exact part number amp from an E46 convertible?

[Shonky]

Hi All, I’m going to try and revive this thread as it’s now 2026; and my HK amp has died on the passenger channels. It started as a cracking popping sound like an aux cord being adjusted. To now the passenger speakers no longer are receiving voltage. I have also confirmed there is no break in the wires.

My question has anyone tried amps from other newer chassis codes. Or on eBay do I have to replace with exact part number amp from an E46 convertible?

Are you sure it's the HK amp? The BM54 is still in the chain and the hybrid amp modules in them are known to fail. Can check the inputs to the HK amp if you want but I'll bet it's your BM54.

[WestBankM4]

Hi All, I’m going to try and revive this thread as it’s now 2026; and my HK amp has died on the passenger channels. It started as a cracking popping sound like an aux cord being adjusted. To now the passenger speakers no longer are receiving voltage. I have also confirmed there is no break in the wires.

My question has anyone tried amps from other newer chassis codes. Or on eBay do I have to replace with exact part number amp from an E46 convertible?

If half your speakers are working and the other half are not, it's your BM54 my friend. I had the exact same symptoms, the good news is, if you want to replace it, you can buy a used one from eBay from a Land Rover L322, they're all made by Becker. There's also a guy in the UK that can do the repair for you as well as "upgrade" the amp units inside of the BM54 giving better sound quality than factory. https://carphonics.co.uk/

[Shonky]

Better quality is arguable IMO.

I actually am currently running half and half. My right side died and I replaced with a similar unit using a quality amplifier part. But I only wired in the two right hand channels as an experiment.

Aside from a minor level difference (new amp is a bit louder so need to adjust balance) I don't hear a significant difference. Of course audio quality is very subjective.

Either way it's the simplest fix and definitely DIYable if you can solder.

[WestBankM4]

I wanted to bump this thread since I just purchased a new amplifier from the Netherworld. It's the original BSW Amp for the convertibles, that came with a ski pass sub. maw1124 I have some questions,

1. Are you aware which BSW sub kit this amp came from on convertibles?
2. What was the OEM enclosure and sub? Was it just a sub from BSW that mounted in the ski pass box or did BSW give a whole new box you'd install in the OEM location on convertibles?
3. If I was to buy an aftermarket sub and just build my own box for my coupe, what impedance should I be looking at for the sub?

I can tell from the amp itself that its a 2-channel w/ a bridged 4Ω output.

[maw1124]

WestBankM4

Looks just like the one that came with the original BSW Kit.

(1) I'm only aware of only 1 subwoofer kit they made, which is the one I have. That's the amp that came with it.

(2) BSW gave you a whole mounting hardware kit to mount the sub. See the instructions attached. Nothing that can't be fabricated. But it went in place of the ski pass. Installed, it looks like the pic. The black surround is some sort of thick plastic / fiberglass. It was originally a free air subwoofer, although my guys built a box around mine. (Sorry, don't have pics and that car is in another state). I've been thinking of changing the subwoofer to an AudioMobile unit I use in another car, which would also make use of a small box. In mine, the box, the amp and the cabin amp are all mounted behind the rear seat, and then a carpet matched removable panel (installer constructed, so I can adjust the amp settings) separate that equipment from the rest of the trunk, allowing the convertible enclosure to move as the factory designed. Hopefully that makes sense.

(3) I'm pretty sure it's all 8 ohms, although I can't guarantee that. It was designed to work with their Stage 1 cabin speaker set, which it does. I went with Dynavin + aftermarket amplification everywhere and don't recall fussing around with impedances. But come to think about it I didn't do the install or even select the cabin amp (Hertz 4x85) so I wouldn't know.

With my first Dynavin (D99) I had horrible engine whine and other noise issues that I recall my guys futzing around with an impedance meter to try to sort out. Unfortunately I don't recall (and didn't document) what values they were coming up with. But other than that it was PnP.

I will say it sounded the best with the factory head unit for which it was designed. But that didn't have a separate subwoofer level control so it was hit and miss crossover wise. Going to Dynavin + Hertz for the cabin yielded much better results but cost more time, money and grey matter. The D99, then the N7Pro + a Hertz cabin amp.

I've attached what I have on this from my files. Hopefully it helps. I bought the stuff used off eBay for a great price and just took it to my installer and said "put this in, it should all be PnP -- check the website for any questions" essentially.

maw

EDIT... Unfortunately back then (2012) they were marketing this as "proprietary" so they were scarce on all of the car audio specs we are used to seeing. And they went through some sort of ownership change since then so I don't know if they even have any of these historical records or will give them to you if you ask. I have a RENNtech MB car, same thing -- they even remember the car but I have more paperwork on their work than they do for the car. Rumor back then was this was all Rockford Fosgate stuff, the amp and the free air sub, if that helps. Skip the free air sub though.

[maw1124]

I have to tell you WestBankM4 I'm not sure I'd use that for a coupe unless you can find some 4 Ohm speakers that fit the Coupe. I seem to recall the Coupe uses 6x9 speakers in the rear deck, and I'm sure in the last 15 years you can find some 4 Ohm 6x9" subwoofers. I feel like I had some 20 years ago that I planned to use in a Honda Accord that I never got around to installing before I sold the car. Depending upon the bolt pattern you might even get away with dual 8" subs mounted under the rear deck -- nothing says the cutouts have to match.

That amp may or may not work unbridged (and the BSW sub may have indeed been 4 Ohms), but it's certainly not the best. I used it because I got it with the kit for $400 used. And that was mainly for the easy PnP, packaged, engineered, "kit" fitment, to support an American company trying to support the E46M community, all that fun stuff. If I was to redo it today I'd go a completely different direction, which is where I'll end up if I replace the sub -- only the mounting hardware from the original kit will have survived.

A good head unit, amplified front stage cabin and deck sub is all you need to make it sound good. The cabin is tiny. Mine is overkill -- I was shooting for good sound with the top down at highway speeds.

maw