[mistermaker*]

Hi all,

About 2 months ago I decided to do a base audio upgrade from my original system to a vine powerbox 65.4m + Focal 100L midrange + tweeters (front doors only for now). This is on my F36.

Today I believe to have blown the driver side door mid range as I noticed a burning smell followed by a lot of crackling/popping sounds. I’d like some advice on what could’ve caused this, i’m a newbie and did this install myself (probably should’ve gone to a professional but I love to DIY).

This is how I had it set up:
Amp full on front, HPF on rear, gain on both set to about half way (before crackling starts on full volume).
HU coded to HIFI and bass increased by +3 (found it to sound better over the base coding).

I usually play volume on 100%.

On some Amp set up guides I see they mention to turn the volume to 75% when setting the gain, but I find that to limit my max volume to 75% before I hear distortion, and I want 100% volume.

Did I set up the amp wrong? Pushing too much bass into the speakers?

Would be good to hear your thoughts and advice. Always trying to improve my skills.

[Billfitz]

What is preventing the low frequencies from going to the door midranges? If it's just an the inline capacitor of the stock base system that doesn't give enough protection. The Hi-Fi and H-K systems separately amplify the underseat woofers and electronically high pass the mid/tweeter channels to give enough protection with the higher power of their amps.

[mistermaker*]

Currently there isn’t anything preventing those low frequencies. I’ve just gone through with the ‘plug&play’ route and added just the amplifier and front door speakers. Haven’t added anything else. Are you suggesting I separate the underseat woofers from the door speakers and power them separately?

[Billfitz]

It's an absolute necessity. You've already found out the penalty for not doing so. You also need to ditch the 6.5 inch woofers in favor of 8 inch, and don't spend the kind of money you did on the Focals, there's no point. I'd find some used OEM Hi-Fi woofers. Then high pass the front doors.

[mistermaker*]

Thanks for the info so far. Definitely have faced the consequences. Focal doesn’t offer the midrange on its own so i’d have to buy the whole set again. Indeed a quick search shows the 8” HI-FI woofer is good enough. How would I go about separating the subs from the door? My amp has 4 channels with 4ohm impedance, but the HIFI woofers are 2ohm. I’m not looking to upgrade the rear door speakers so if those are powered by the HU then that isn’t a problem. Some advice/links would be awesome.
Thanks again!

[quakerroatmeal]

Most likely it's because you played it at 100% volume causing audio distortion / clipping and it finally gave out on you. If you want it louder you need to upgrade accordingly. I'm not sure of any plug and play amp that would satisfy your need though. Most plug and play amps I've seen are all around 65w x 4.

[Billfitz]

Clipping had nothing to do with it. The stock base setup uses a simple capacitor to reduce the low frequencies going to the front door midranges. It's sufficient when all that's powering them is the 15 watts or so that the HU will put out. It's not sufficient with more power than that.

[shiftdnb]

Billfitz is right. The speakers can only handle certain frequencies. You basically have to put in crossovers or run a DSP. I have Morel 402 Hybrids in the doors and replaced the Hi-Fi amp with a Helix P-SixMkII that is an amp and a DSP purchased through MusicarNW. They built a wiring harness and a platform that made the installation pretty much plug and play for me. I just had to run a larger gauge wire and proper fuse to the Helix as the vehicle power is not enough. I then run RCA from that to a CT Sounds 500.1 amp to a sub box I built for the space under the cargo floor.

[NealfromNZ]

Next time around put some passive crossovers in. You could either make Bills ones or get something like the focal es100k crossover which has both low pass and high pass ( high pass filter is switchable cross over board ) on the mid bass so it runs roughly from 110hz to 3500 hz and then the tweeter runs up from 3500 hz. It protects the speaker from running lower bass ranges that takes it beyond is mechanical limits.

https://www.woofersetc.com/focal-xo-...ystem-set.html

[Billfitz]

My passive crossover goes between the midrange and tweeter. That Focal has a high pass for the midrange as well, but it's still no substitute for separately amplifying the woofers and mids/tweets with an active crossover.

[NealfromNZ]

Sure Bill, was thinking it would allow OP to keep 4 x 65 rms channel amp and current setup. Crossover would just need inserting into door speaker wiring.

[Billfitz]

For the price of that crossover you can buy a sub amp.

[mistermaker*]

I am trying to take a low budget approach as my aim is to gain clarity and volume, although i do understand a low budget does come with limitations. Would I need a DSP if I was to separate the woofers from the mids or can I purchase just a sub amp to power the woofers? If I was to go with the latter, how would the connection to both amps be made as the mids are directly connected to the woofers, is there a wiring harness I could buy? On other forums I’ve seen some users bridge both woofers to amplify them but not sure how the doors would still get their feed.

Edit: Would the Technic 2/4 wiring harness provide a better solution?

[Billfitz]

Just an amp would work. You'd use a 'Y' connection to give it the same input signal as your other amp. Disconnect the existing speaker cables at the woofers, using electrical tape to insulate them, running new speaker cables from the sub amp to the woofers.

[mistermaker*]

Forgive me if i sound confused. I am currently using the connects2 harness to wire up the amp (vibe 65.4m). Sticking to the vibe theme.. could I use the 400.1 micro amp for this or do you suggest a different amp?
So new cabling will send feed from sub amp to the sub. The door speakers are connected in line, will these wires remain as is? I am unsure how i would connect the door speakers directly to the 65.4 amp.

[Billfitz]

The brand of amp doesn't matter. The door speakers are already connected to the 65.4 amp. All you need to do is disconnect the woofers.

[NealfromNZ]

I wouldn’t go down the path of running a mono sub amp at that power rating into the base audio underset woofers. It’s too powerful for those speakers and you’ll get more smoke.

But if you were to do a separate amp for underseat the technic harness would spilt out the doors from the underseats.

The door wires need a bridge connection which the underseat woofer terminal which the technic harness does. Within the door run connect pins 2&3 connect to 1&4 respectivelyz.

So you could go new amp ( $100 ? ) ( go stereo not mono ) for underseat pair + Techinc harness ( $85 ).

Or do what I suggested and run three passive crossover ($100 ) with high and low pass filters on the door with the cross over located In the door ( $30 worth of BMW speaker connect adapters) and some 18 gauge speaker wire and stay with your current amp setup.

But you also need to understand amp gains and volume control on idrive . No point in overdriving speakers for the sake of getting to 100 % on the idrive

[mistermaker*]

I would be upgrading the base woofers, Billfitz suggested the HIFI ones should be enough, or one that can take even more power. I personally like the technic harness set-up with sub amp. If possible i’d still like to utilise the vibe 400.1 amp as it’s an easy install and takes the rca cables from the 65.4 amp.

The technic 2/4 harness - based on pictures - has 6 wiring looms, how would these connect up to the car exactly? Im familiar with bridging the pins for the connector going into the sub, but unsure how the technic harness would come into play.

Couple questions:
Will there be a need for splicing into the wires coming out of the 65.4 amp?
The 400.1 sub amp only has an output for a single sub, how would i connect both subs?

[NealfromNZ]

The Techinc harness does

1 , A new cable run for running woofers directly off an amplifier in stereo

2 Provides bridge connections so door speakers runs can operate independently from amplifier

3 Provided pigtail for after market underseat woofers.

I’m not sure why lots of people call ( probably BMW ) the underseat woofers subs. They are not subs . Subs typically don’t run into the direction frequency range that the BMW underseat woofers do.

So running the pair in mono will have tradeoffs. But if you want to run a new pair off a single channel amp you’d go run new wiring to the woofers. At the amp end you’d either run the wires in so the woofers are in parallel if you get HK or 8 ohms woofers or series in you get the 2 ohm hifi woofers.


On the door speakers you also want to set a HPF filter on the amp around 150hz for a 12 db slope to protect it from deeper bass notes.

First pic is a sub 😀
Second pic is not a sub

[NealfromNZ]

Also hit up Focal head office or Focal USA , there are a lot of us Focal speaker owners and I’d expect spare parts and drivers to be available. If Focal run a PNP range for BMW they should have spares !

It’s not on that you would have to replace an entire set for only one speaker that has become damaged for whatever reason.

[Billfitz]

Originally Posted by NealfromNZ

I’m not sure why lots of people call ( probably BMW ) the underseat woofers subs. They are not subs . Subs typically don’t run into the direction frequency range that the BMW underseat woofers do.

BMW is hardly alone in calling what are technically woofers subs. The original definition of woofers were drivers that went to 40Hz, while subwoofers were drivers that went below...therefore sub...where woofers did. But that was forty years ago. Woofers that went from 40Hz to 500Hz and midranges that didn't go below 500Hz have nearly disappeared, replaced by what are now called subs that go to anywhere from 80 to 125Hz, and midbasses that take over from there. As for the BMW woofers, they only run to 125Hz, which isn't in the directional frequencies. That's roughly 250Hz and higher. One can hear directional output from woofers crossed over at 125Hz, but what's being heard is harmonics. When placed under the seat those harmonics are acoustically filtered, making them very difficult to hear, as they're also masked by the much higher output of the door speakers.

[mistermaker*]

That makes sense. I've gone ahead and ordered the 2/4 harness and sub amp. Just waiting on Focal to get back to me on spare parts/replacement.

I'll attempt the install and update the thread with how it goes or questions if I have any.

Thanks all for the help! Much appreciated