[Tronner]

So I bought the Match Up 7BMW amp to improve the Hifi 676 stereo. That upgrade has been great. Imaging is much better and it gets the most out of the underseat "subs". But being a bit of a basshead, I felt like I still needed more oomph, so I decided to add an aftermarket amp and sub. I've tried two different subs at two different price points and think I can offer a few solid recommendations depending on budget.

The amp is a Rockford Fosgate Punch P300x1 running at 2 ohms. Data sheet says it's putting out 450 watts (rated at 300). Both of the subs I've tried are dual 4-ohm voice coil shallow mount subs. I tend to like 10" subs the best. I think they sound great with most music, the boxes are a bit smaller to leave a tiny bit of storage space under the floor, and good ones can have ALMOST as much bass as I want if I really want to bump something.

Option 1: Rockford Fosgate Punch P3S Shallow Mount ($189 - shipping was FAST direct from RF). I used an ATREND 10SME B-Box from Amazon ($50ish shipped). You can see it here: https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

The box description says it's .51 cu ft internal which is a perfect match for the RF sub, and it fits absolutely perfectly in the storage area. It's a tiny bit wider front to back, so it won't slide forward or backward in the well even if not bolted down (which I would definitely do regardless). The box is great except for their packaging, which doesn't have any padding so the thing showed up with a dinged corner and a bent metal logo piece that I removed, which left a bit of a bare spot in the carpet that I just wrote off since it was going to be unseen most of the time. It also showed up black instead of gray like the pictures on Amazon, which was a pleasant surprise. I caulked the inside of the box and the terminal to make sure it was sealed up nicely.

Option 2: JL Audio CS110LGTW3 ($438 from Crutchfield with quick shipping as well). This is the pre-loaded shallow mount option with a .48 cu ft box and a grille, wired at 2-ohms. It also fits really well in the storage area, but the ATREND fits slightly better IMO. The JL packaging was superb, and the fit / finish is definitely a notch above the ATREND box.

Sound: honestly I think the Punch 10 sounds very slightly better and more controlled at most volumes, and most frequencies. The JL has an xmax of 15+ mm of excursion vs only 8.8 for the Punch, so it puts out a bit more bass, but it's not quite as controlled. The JL plays low bass (like 30hz) a little better at fairly extreme volumes, and the xmax allows it to play a few db louder before it starts to distort. Both subs really impress me though for shallow mount subs which always give up something to subs that have beefier magnets and big excursion.

Ultimately I chose to keep the JL because I do like to really push it once in a while and it just has a bit more head room and can play at a considerable volume before distorting. The RF sounds great, and can play PLENTY loud for most people I'm sure. If you're looking for a very easy, almost plug-n-play solution and don't mind almost double the price just get the JL and be done. If you'd like to have a really nice sounding sub without spending too much money and you don't care to really bump some rap and bass music once in a while then the RF with the ATREND box is a great option and probably fits the storage space the best. One other option would be to buy just the JL TW3 10" and get the Atrend box. Just beware it might show up dinged up, and I might not put a grille on it because it will be really close to hitting the underside of the floor panel. And if anyone wants a freshly broken in RF Punch 10" (like maybe 3 hours of total playing time) I have one for sale :-)

Pics of each installed:

[RedJon]

Excellent, any pics of how you wired in the amp and connected the sub?

[Alias1431]

Thank you! I've been weighing my options for a subwoofer for months now. This helps a lot. I'd like to echo RedJon, how do you hook up the amp? Also, your amp seems discontinued, how much was it? Do you have a current recommendation? And this might be a dumb question, but why put the sub under the floor? Won't that muffle the sound like 80%?

[Tronner]

That is interesting on the amp - I ordered it on June 10th - can't believe they're out of stock most places now. Maybe they're making a new version of it soon. It was on sale direct through the RF site for $150 but it seems they've gone up now. To be honest I would love to find one that is a little bit smaller in physical size. Any mono amp that's stable to 2 ohms and puts out around 300 watts or more would work fine. It fits in the cubby to the left of the storage area, where the stock amp is, but just barely. Mounting it was a bit of a pain and I'm still not fully in love with how it's in there. I'll take pictures here in a bit, but there are a couple from pierreye in the MatchUp7 thread. Powerful amp though.

As for wiring, the MatchUp7 amp has a remote out and a line out for a separate amp so it couldn't be easier. It's mounted about 4" from the RF amp, so you literally just run one small remote wire and about a 1' RCA over to the new amp. Power and ground are right there because the battery is in the rear. I actually just used the battery ground since I'm using 8ga wire and the run was only like two feet. I'll get pics of all of it up shortly.

[Tronner]

Originally Posted by Alias1431

And this might be a dumb question, but why put the sub under the floor? Won't that muffle the sound like 80%?

Forgot to answer this one - but not at all! Same as having them in the trunk, or under a seat, etc. Subwoofer bass can be felt and heard from many locations, and it hits hard under the floor no problem. Plus I didn't want to take up any hatch space or have the sub where I throw sports gear, my dog is roaming around, etc. The only thing is I do need to address a few little rattles that I hear from the floor panel itself. I think some cheap sound deadener will help quite a bit. When I was comparing the two subs back and forth I did a lot of it with the floor panel up to avoid any rattles and the bass was nearly the same as with the panel down.

[Tronner]

Here are a few pics of the install. I could easily drill one little hole in the storage well floor and run the speaker wire through there to hide it, but I like not drilling holes in things and I don't mind that little bit of wire showing. Might cover it with some tape. Power and ground wire run under the plastic at the very back of the car. Really easy access to the cubby on the left. Just mounting the amp is a little challenging. I was reading up on the SKAR SK-M5001D which could be a nice option that's a little smaller, but I did read a few reviews that say it runs hot.

[mattldm]

Does the floor clear the mesh grill on that JL or does it sit right on it when closed. It looks close from the pics above, otherwise that’s a perfect fit

Did you run a remote bass control for the sub?

[foglem]

Tronner, if you’re still around I have to ask... Does your cover over that area still close with your amp installed there? I placed the same amp in mine and for the life of me can’t understand how you managed to get it to fit and close...

[Kid Red]

Curious if the floor rattles/vibrates or flutters at all when the bass hits?

[foglem]

My downfiring 12” certainly rattled the floor if I turn it upright. But down firing seems to be quiet.

[foglem]

Originally Posted by foglem

Tronner, if you’re still around I have to ask... Does your cover over that area still close with your amp installed there? I placed the same amp in mine and for the life of me can’t understand how you managed to get it to fit and close...

I did get a reply here and wanted to update for those like me that might be searching for answers... At least one person who made this fit had to bend the metal framing in the compartment to make the amp sit further in and the cover close. That said, my plan is to buy a spare of the trim panel and modify it to fit without mangling my car's parts. Once I get it and start the slicing and dicing I'll update here since it's most relevant to this issue.

[lo_cheng]

Thank you for sharing.
I already have Up7BMW Amp for over a year now and researching options to add another sub as well, your post helps a lot.

Some question:
1). Looking at the ATREND box, seem like the 10" vs 12", only differ in size is the 12" box is almost 4 inch longer. I see in your picture there are space on both side. Do you think the 12" will fit??

ATREND 10 inch box
Height: 15.25”, Width: 20.125”, Depth: 5.125”

ATREND 12 inch box
Height: 15.25”, Width: 24”, Depth: 5.125"


2). For the amp. How many hole and how difficult it is to drill hole to mount it? Can you still close the panel after amp installation?

3). If you put something on top of the area where the sub are, does it create rattle noise?

Thanks

[foglem]

lo_cheng,

I went with a Kicker 48CVTDF122 for a 12" that fits. BARELY fits@ 21.375"W x 6.375"H x 14.6125"D.

That Atrend looks like it would fit even tighter, you've got 25x15x6.375 roughly. The edges bevel so the 15.25 fits barely, but started to ride up the sides.

I didn't drill holes to mount my amp; choosing to instead use industrial zipties to hold it to the existing frame metal. But I don't want to bend it to make it fit like most appearently are behind the stock cover.

Finally rattle/noise. So far I don't seem to be hearing any except when I tried to aim my subwoofer up. It's designed to be downfiring on the kicker so luckily aimed down it doesn't seem to rattle. Someone else would have to comment on the Atrend. What sub would you put in it?

[lo_cheng]

I have a shop Recommend this JL Active sub to me:

https://www.jlaudio.com/collections/...-systems-93334

about 18.5" x 12" x 5"

But I find it odd for 0.25ohm

Where you able to close the panel after the amp installed?

[lo_cheng]

Wow.... the kicker look nice, and good price point too.

How does it sound? Do you have picture how the kicker fit in the space??

I currently have UP7BMW installed, everything etc are stock, but really lack of some base.

I watched video that replace under seat sub and doesn't like need to use hammer to crack it open. It really worry me. So I looking for additional sub option.

[plagm]

Originally Posted by lo_cheng

I have a shop Recommend this JL Active sub to me:

https://www.jlaudio.com/collections/...-systems-93334

about 18.5" x 12" x 5"

But I find it odd for 0.25ohm

Where you able to close the panel after the amp installed?

But I find it odd for 0.25ohm,

this is because JL are using a new type of amplifier that has a very low impedance for these subs ( the amp is built into this item). I would trust what they say they are very good at it.

[MrAndrewArnold]

Where did you tie the line out converter for the RCAs at?

[foglem]

Originally Posted by MrAndrewArnold

Where did you tie the line out converter for the RCAs at?

If you use a Match UP 7BMW there is no line out converter as it gives you a RCA output for a subwoofer channel. See other threads (Sor's steath subwoofer install for instance) for more detail on the lines you'd need to tap. I know there is also a semi-expensive wiring harness you can use to get those signals.

I'll take a pic of that Kicker box in the space later today when I get out. I haven't gotten the cover to close yet. As I mentioned I bought a second cover and am going to modify it to fit. At least that's the plan right now.

[Alias1431]

Originally Posted by plagm

But I find it odd for 0.25ohm,

this is because JL are using a new type of amplifier that has a very low impedance for these subs ( the amp is built into this item). I would trust what they say they are very good at it.

If you had to pick a line/brand of all-in-one subs, who would you go with? RF is popular, but I hear good things about JL. I know there's a few brands out there.

[foglem]

Here is the picture of that Kicker box.

[lo_cheng]

Originally Posted by foglem

Here is the picture of that Kicker box.

oh, it fit very nicely. so tempting.

I think most difficult part would be mount the amp and still able to close the panel.

[BMWZ4]

I'm thinking I want to pick up a 10" JLAudio sub, but no a powered version. So dumb question, what do the RCA connectors on the sub connect to on the OEM amp?