# Stereo Integrity BM Mk iV review



## pereze (Mar 26, 2011)

It has been a while since I have been checking out these forums, but I bought this subwoofer during the promo and wanted to FINALLY write a review. I will say, I haven't had a ton of listening time yet and I am still playing with a few things, but I will try to get to that in a second. 

You can find the website for this product here:
BM mk IV 12″ Subwoofer | Stereo Integrity


I bought this earlier in the year and then our house finally sold, right when we had 2 vacations planned (not complaining, just giving context) and we ended up moving 4 days before school started. It was and is crazy with everything going on. But enough of that, I finally was able to find some tools and pull this box together.

I think some of the other threads have covered how the subs are shipped. Over pack much. 


















There are boxes within boxes, within pads within boxes,etc. You finally get to the white box and then open it only to find another box with foam and more cardboard to protect the surround.

Here is the box. It is 13.5X13.5x8.75. I am very proud of the fact that I built this with a circular saw and it actually came together nicely (the cutout for the sub was a router).











As far as box volume, it is a little on the high side, but right about optimal at .55 internal volume when subtracting for woofer displacement. I am powering this with a Zapco DC500.1 with the sub wired to 8 ohm. I have the stock head unit feeding the dc500 and a dc 650. The DC650 is powering some Dayton RS180 woofers in the door and some Vifa XT25sc's on the dash. 

This is all mounted in my Nissan Leaf. That's right, I am not ashamed....:blush:










I am still breaking it in and don't feel like I can give much feedback right now. I have listened to a wide range of music including:
Sam Hunt
Blake Shelton
Brandie Carlile
Macklemore
One Republic
Katy Perry (What, how did that get int here? It's not mine, I swear)
Luke Bryan
NeedtoBreathe
and a few others.

I will provide more detail soon, but I also want to note that I have experienced some odd sounds from my previous subwoofer when the sub is in the rear hatch. It seems like cancellation. In order to not have that issue, this subwoofer is mounted in my passenger seat floor board. 

If anyone in Atlanta has an o-Scope and wants some lunch or beers, let me know. I would really like to make sure I have my gains set correctly and am feeding a clean signal. I am being overly cautious with my setup currently and want to let it loose a little but also don't want to fry this beautiful subwoofer. 

More soon.


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## SO20thCentury (Sep 18, 2014)

So howz Katie Perry sounding in the ol' leaf?
Have you got more time in w the sub? 
How do you like your Leaf? Is the hatch area good-sized? Wonder what was up with yr previous sub back there...?
I kinda like Leafs


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## sirbOOm (Jan 24, 2013)

I have a DD-1 if you want to use that to set gains.


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## pereze (Mar 26, 2011)

SO20thCentury said:


> So howz Katie Perry sounding in the ol' leaf?
> Have you got more time in w the sub?
> How do you like your Leaf? Is the hatch area good-sized? Wonder what was up with yr previous sub back there...?
> I kinda like Leafs


I have gotten a good bit more time. About 1.5 hours each day.  I don't know what Katy Perry sounds like since I don't listen to that... HA!

I like the Leaf. The hatch is a very good size. I have been able to fit almost everything I would want. I looked at the Focus electric but they take up half the hatch with the batteries where as the leaf has the batteries under the seats running along the floor board. 

My previous sub is/was an Infinity Kappa 10.1D. I have had it forever and its a good sub but I kept wondering about other subs. In my previous car I had switched to an IB setup with an AE IB15, which I loved. When I went to the leaf, an IB setup is difficult to work out (although I did consider it). I wanted to try the BM MkiV because if its shallow depth (taking up less room and potential for front seat mounting) and the XBL2 motor like in the AE IB15. 

I am really liking it so far. I ended up moving it back to the hatch because my wife needed to drive the car and I didn't want her accidentally damaging it. I could see her coming in the car and just throwing her purse down on it. 

I like the front seat, but it actually sounds pretty good in the back as well now that I have some tuning done. It is clean and fast. I am hoping to get my gains set in the next week or so with an o-scope and then really turn it up. I have been conservative with the volume to break it in and not burn it up.


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## pereze (Mar 26, 2011)

sirbOOm said:


> I have a DD-1 if you want to use that to set gains.


Thanks for the offer! I may take you up, but I picked up some resistors to try hooking into my computer and using some software. I have a mobile-pre that I use for my Behringer mic that I may try using since I think it will take a higher voltage.  Once I get the gains set, I will do some sweeps with my un-calibrated mic and see where I am at. 

One funny note, sound sensations installed my very first sub. It was a Kicker in the mid 90's powered by a Soundstream reference amp. I don't know if it nostalgia or that it was my first or what, but that thing sounded amazing to me. Sure the box took up the majority of my hatch, but it sounded great.


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