[h3adbussa78]

Originally Posted by RCM78

Done, File is called "Morel TM8 Tune"

Thank you! You must have been posting this when I was replying to another message. Just popped up on refresh. I'll give your file a look and compare how I can improve or change mine to perform better. Hoping to learn from your configuration for future reference.

You're also welcome to the files in there although they are for the G30 and aren't configured for having the MEC installed. They are mostly the base tunes provided to me, except the ones with modified in the name.

[omalley72]

What under-seat subs are recommended to use along with the AlphaOne amp/dsp? Just installed the amp and working on tuning but I’m quickly learning the BMW HK subs just won’t do it. I’d rather not go with a box in the truck, just keep things located where they are. Any input is appreciated

[h3adbussa78]

Originally Posted by omalley72

What under-seat subs are recommended to use along with the AlphaOne amp/dsp? Just installed the amp and working on tuning but I’m quickly learning the BMW HK subs just won’t do it. I’d rather not go with a box in the truck, just keep things located where they are. Any input is appreciated

I went with these but it's really up to your own taste and how far you want to go with upgrading your system. Also...Your budget.

https://www.amazon.com/gp/product/B0...e?ie=UTF8&th=1

[I800C0LLECT]

Originally Posted by omalley72

What under-seat subs are recommended to use along with the AlphaOne amp/dsp? Just installed the amp and working on tuning but I’m quickly learning the BMW HK subs just won’t do it. I’d rather not go with a box in the truck, just keep things located where they are. Any input is appreciated

They aren't bad if you cut them off at 40Hz. Not a lot of songs go below that

[RCM78]

Originally Posted by I800C0LLECT

They aren't bad if you cut them off at 40Hz. Not a lot of songs go below that

I had them crossed at 60hz and still found them to have audible distortion at 85-90db listening volume.

[RCM78]

Originally Posted by omalley72

What under-seat subs are recommended to use along with the AlphaOne amp/dsp? Just installed the amp and working on tuning but I’m quickly learning the BMW HK subs just won’t do it. I’d rather not go with a box in the truck, just keep things located where they are. Any input is appreciated

I went with Stereo Integrity TM8's but they are not a direct fit.

These Helix shallow subs are direct replacements with the correct adapter. They will provide a huge improvement over the factory subs.
https://www.audiotec-fischer.de/en/h.../ci5-s200fm-s2

[I800C0LLECT]

Originally Posted by RCM78

I had them crossed at 60hz and still found them to have audible distortion at 85-90db listening volume.

I don't have any distortion plots but I can get them pretty crispy. I know the rear speakers get very distorted though. I have the system balance all the way forward. Mine are 50Hz to 200Hz with 24dB slopes

[m440i804]

Originally Posted by RCM78

I went with Stereo Integrity TM8's but they are not a direct fit.

These Helix shallow subs are direct replacements with the correct adapter. They will provide a huge improvement over the factory subs.
https://www.audiotec-fischer.de/en/helix/speakers/compose/i5/ci5-s200fm-s2

How hard to get the tm8’s under the seats? Any pics?

[RCM78]

Originally Posted by m440i804

How hard to get the tm8’s under the seats? Any pics?

The 4 series has less room under the seats than the 3.
I bought these adapters
https://www.ebay.com/itm/18608836934...mis&media=COPY
Installed them upside down and they worked. Problem is getting the factory grills back on. The TM8’s sit too high to clear the grill.

They sound fantastic though.

[phc77]

Originally Posted by RCM78

The 4 series has less room under the seats than the 3.
I bought these adapters
https://www.ebay.com/itm/18608836934...mis&media=COPY
Installed them upside down and they worked. Problem is getting the factory grills back on. The TM8’s sit too high to clear the grill.

They sound fantastic though.

I think it's worth doing without the protective grille, given the location, there's no risk.
The upside-down installation is a good idea. The woofer is out of the box.
Do these adapters fit the factory screw locations?
Is the assembly well sealed?

[RCM78]

Originally Posted by phc77

I think it's worth doing without the protective grille, given the location, there's no risk.
The upside-down installation is a good idea. The woofer is out of the box.
Do these adapters fit the factory screw locations?
Is the assembly well sealed?

Due to the space limitations, the under seat enclosure is open on the bottom and sealed to the car with a gasket material. I added soundskinz to the opening where the cars metal floor was exposed. It is vented into the left and right rocker area. I believe the 3 series enclosures are sealed on the bottom.

The adapter fits perfectly. Just drill pilot holes to avoid splitting the MDF. I also cut soundskinz to serve as gaskets below the adapter and under the speaker flange.

I have zero resonance from the under seat speakers.