Here are only 10

 

It's the new math. They count the dual cone speakers as 2.

 

Low frequencies from a subwoofer are omnidirectional, so placement is not critical, even in the trunk. Rear door speakers don't matter much because most of the sound is absorbed in the back before a very minor amount reaches the front, and many cars no longer include rear door speakers. That is why changing the rear speakers are a waste of money... unless you care what the back seat occupants want to hear. Future tech cars will move more towards using a multi-speaker array (think sound bar for a home theatre) built into a simpler dash design with a sub elsewhere to fill in the lows. Saves a lot of money building the car and the sound quality is still good, improved with properly done digital signal processing. A few in China already use this design. Door speakers in general are problematic for they tend to create many sound cancellation nodes and problems especially with the center console hump that often leads to a very noticeable dip in the 400hz midrange. It's just new ideas are slow to adopt in the US.

 

haha i would never have guessed.i see now why sound is so treble.i looked RX forums and they do claim the same.

 

Yes, instead of base <sic>

YMMV

MidCow3

 

Whoosh

YMMV,
MidCow3

 

Can't delete messages, lol...

 

Thanks for all the great info here, it really helped with my research. My overkill notes below for the over researchers among us.

Just "finished" installing a sub in my '25 350H w/o Mark Levinson.

Main Parts
Sub - Hertz MPBX 250 S2
Amp - Wavtech link500.1mini

Factory Speaker Wire
Speaker Connector - Metra 72-8109
Speaker Wire - Wire Barn 18 AWG GXL
Speaker Wire Sleeve - JT&T Expandable Sleeving 1/8" ID (had this laying around from a project on my Tacoma)
Misc Heat Shrink - Adhesive Lined Kit
Heat Shrink Butt Connectors - Random kit from amazon that isn't there anymore, looks very similar to this one, 2x red 18-22AWG butt connectors

Subwoofer Wire
Subwoofer Wire - Karma SS Tinned Copper 12 AWG
Subwoofer Wire Pants - Knu Konceptz (totally not necessary, but I just wanted to try them out)

Battery Wires
Battery Terminals - Rockford Fosgate RFTS4
Battery Wire - Rockford Fosgate RFK4D (I had some 4 AWG from this kit laying around)
Battery Wire Sleeve - JT&T Expandable Sleeving 1/2" ID (Also something I had laying around, just wanted the ground cable to be black since all I had was red 4 AWG)
Heat shrink - Dual Wall Adhesive Lined 3:1 4 AWG
Fuse Holder - Rockford Fosgate RFK4D (also from that old RF kit I had laying around)
Fuse - Blue Sea 50A (this got shipping delayed, currently has a 100A in there)

Misc
Tesa Tape for wrapping the metra connector
Wire Ferrules
M5 Screws
Silicone Vacuum Hose had this laying around from some 3D printer stuff. I cut sections to make rubber standoffs to mount the amp to the sub.
NVX SDDK12 Sound Deadener open box discount and was certain I could find a couple spots to put some.
3M VHB Velcro for attaching the fuse holder to the floor and temporarily securing the sub enclosure until I secure it fully.
Some 3D printed Parts

Notes on parts selection:

• I wanted the biggest most powerful amp/sub I could fit... with some caveats.
• It had to fit under the cargo deck and the cargo deck had to be flush and still support anything I throw on top of it.
• I didn't want to cut or drill anything as the car is still very new to me. (I did end up cutting the battery terminal cover a little bit for positive cable clearance.)
• I didn't want to spend an egregious amount of money. Yea, it still wasn't cheap but not custom enclosure expensive.
• I knew I wanted to mount the amp to the sub and due to the height of the enclosure it limited my options to only a few amps.
• 4 AWG and 12 AWG are overkill for the length these need to be run, but it's what I had on hand.
• Speaker Wire Pants, Wire Ferrules, Tesa Tape, Sound deadener and Silicone vacuum hose are absolutely NOT required. I just tend to be extra when it comes to this kind of stuff.
• The M5 screws and 3D printed parts are for risers on the subwoofer legs. The cargo deck floor is not flat and I wanted to shim it out to be flatter.
• Silicone Vacuum hose is for rubber standoffs since I mounted the amp to the sub enclosure.
• I also have the bass ****, but I'm trying to tune it close enough that I don't have to use it. We shall see...

Shoutouts:
Audio Matrix in Torrance, CA for having the subwoofer in stock locally and letting me test fit a display model in the cargo area before I purchased it.
Creative Audio had an open box Wavtech amp for a great price, looked brand new and shipped fast. Nolan on their weekend customer support for answering all my questions about open box warranties and such.
All the folks in this thread that contributed to the discussion. Thank you.

More posts to follow with install and tuning notes.
Also I'll take some pictures tomorrow when my 50A fuse arrives.

Spoilers: It sounds really good.

 

Question: why didn't you use larger gauge wire for speaker wire? 18 gauge is pretty small

YMMV,

MidCow3

 

Great question.

I tried to use larger. But, it just didn't fit and ultimately I decided it didn't matter anyways.

• I couldn't fit my other 16 AWG speaker wire in the butt connector or into the speaker level input on the amp.
• The speaker level input on the amp needs a jumper to both channels to produce full power and I couldn't fit 16 AWG and a jumper into the same hole(picture below). I tried for way too long to fit a larger wire + jumper wire.
• The metra connector is 18 AWG and the factory speaker wire is a similar size.
• Even if I could attach a larger AWG wire the weak link would be the metra connector and maybe the factory wire. Everyone has been using the metra connectors without issue.
• There isn't all that much power running through the factory speaker wire and it's a short run of wire.

 

Ok added the 50A fuse and took a couple pictures.


Cargo deck sits nice and level right on top of the sub.


Sub enclosure fits with only removing the one cargo bin.


Here is the power wires run with the 50A fuse and holder.
The fuse holder is mounted using velcro backed with VHB. I've used this on previous installs in 4x4 vehicles and 1/0 AWG wire and it holds great and makes it easy to move when I need to. No Holes needed.


This is the cut I made to the battery terminal cover. to fit the wire out the side.


Here is the Amp mounted to the subwoofer enclosure.
You can also see the standoff I 3D printed in the lower left corner to extend the length of the leg.


The rubber standoffs I cut from silicone vacuum hose to mount the amp to the sub enclosure.


And the speaker harness for the speaker level input wire.

 

Some things I still need to do.

• Secure it properly. It's attached to the floor using the same VHB backed velcro for now. But that isn't a permanent solution.
• Secure the sub wire. It's kinda just hanging there not really secured to anything. I don't want it bouncing around long term.
• Maybe trim the speaker level input wire by a foot or so. It's just needlessly long and not secured to anything either.
• Add a couple more sheets of sound deadener to a couple easily accessible panels. Although these cars are reasonably deadened from the factory compared to most cars.
• Decide if or how I decide to close those gaps around the sub. Ideally I'd like to tie all the factory clips and tabs back into something and prevent anything from falling into those gaps.
• Tuning
  • It's currently set with a ~80hz low pass filter and ~30hz subsonic filter. Gonna let the sub break in a little and see if it changes the response over the next couple dozen hours or so. Then come back and tune it again.
  • Used a 40hz -5db test tone to set gain just below clipping at 50 volume on the head unit. It was a bit much so I brought the gain down a little from there.
  • Bass, mid and treble on the factory head unit are set to the middle for now.
  • RTA readings using pink noise without a calibrated mic were pretty decent, with bass frequencies just a little higher than flat. Which works well for the majority of music I listed to.
  • A little missing clarity up front is more pronounced now and I'm exploring all the options folks have mentioned in this thread so far to replace the dash speakers.
  • Maybe add the bass ****. Trying to not have to run one as I don't haven't seen any mounting options I really like yet. But, I use the one in my truck a lot and will likely end up running one at some point.

So far with the first pass I am really happy. It fills out those low frequencies that were almost completely absent with the factory sub.
It's not weak at all and it's not boomy either. You will feel it and it will rattle the mirror depending on the music.
Very impressed with both the ease of setup with the wavtech amp and the performance of the Hertz sub + enclosure for its size.

 

Super clean!!! I want to do the same in my gas model but with a sealed down firing Kicker 10" Solo Baric...

How does it sound being under the trunk liner and with items in the storage bins? Did you do something to hold down the trunk liner from rattling?

 

Super clean!!!

How does it sound being under the trunk liner and with items in the storage bins? Did you do something to hold down the trunk liner from rattling?


This is what I'd like to install in my non M/L Gas Model. Would appreciate some feedback from this forum.

I'm not sure if the AMP is too much, also not sure which line converter to go with, or if I need one.

I plan on letting a shop do the install due to my lack of knowledge on installing, and I have the gas mode, so I'd have to run wires to the front of the car

Sub: Kicker 10" Down Firing Sealed Solo-Baric
Amp: Kicker 51LX850.1
Wiring Kit: Kicker Amp Wiring Kit
Wire-to-RCA :Kicker Wire-to-RCA Adapter
Line Output Converter: AudioControl LC2i Line Output Converter, or Kicker 47KEYLOC Smart Line Output Converter, or the cheaper Kicker 46KiSLOC Line Output Converter

This was me just placing a 8" model in the area I'd like it to be installed, the shop didn't have a 10" at the time

 

So far it sounds great.
It's only been in for a couple days so I'm still running through a lot of my normal music listening for resonance issues. I haven't really found anything that is annoyingly rattling around yet.

I did lay some sound deadener directly under the sub but I didn't go crazy with it. I doubt it has much impact in this car with the factory deadener/sound absorbing material it already has. But I was already in there anyways and had some deadener material.


I'm running a pretty conversative gain setting on the amp. I originally set it just below clipping with a 40hz -5db signal at 50 volume on the head unit and it was too much for the rest of the system and was overwhelming everything else. And big boomy bass isn't really what I go for these days.
I thought I might try it up firing if I wasn't getting enough bass response down firing, but I don't think I'll be doing that anymore.
The trunk liner still has the hook on the right side holding it down. With the rear seats in the recline position those also hold it down pretty well. I have to put them up to the normal position to unclip it from the storage bin.


That amp looks like it should be fine for that sub.

Kicker 49L7TDF102
2-ohm total impedance
power handling: 500 watts RMS (1000 watts peak power)

Kicker 51LX850.1
500 watts RMS x 1 at 2 ohms

You don't technically need a LOC because the amp has high level inputs and signal sensing turn on. But some LOC's like the 47KEYLOC have additional features for more tuning options.