Subwoofer Project FINISHED!!! (Enclosure Dimensions Included)

[HuskerX5]

I tried searching the almost 50k posts for one that might have mentioned what the Factory Subwoofer Enclosure volume is. I am looking at utilizing the factory enclosure and matching it with an appropriatly sized 10in. subwoofer. Has anyone seen this information? You have to remove the speakers, fill the enclosure up with water, for example, and measure how much went in to get an accurate measurement. Given that the OE enclusure has round corners, using standard methods, for square/rectrangle enclosures, is not accurate. Before I go to these measures, I wanted to see if someone had already done this.

Thanks in advance.

[carlgo]

Originally Posted by HuskerX5

I tried searching the almost 50k posts for one that might have mentioned what the Factory Subwoofer Enclosure volume is. I am looking at utilizing the factory enclosure and matching it with an appropriatly sized 10in. subwoofer. Has anyone seen this information? You have to remove the speakers, fill the enclosure up with water, for example, and measure how much went in to get an accurate measurement. Given that the OE enclusure has round corners, using standard methods, for square/rectrangle enclosures, is not accurate. Before I go to these measures, I wanted to see if someone had already done this.

Thanks in advance.

I admire your attention to detail and physics, but it would be interesting to know why you would bother being so exact. After all, it is just bass playing in what is not the world's quietest vehicle. In the end, no matter what the volume of the enclosure, you have the variables of all sorts of different brands and configurations of woofers. And you have to consider the other speakers, the amplification, the cross-over settings...

All this would have to be measured with scientific instruments in the X, while underway at speed.

In the end, I seriously doubt you would come up with something much better than what has already been done here.

And then it comes down to what is on what music you are playing.

[HuskerX5]

Carlgo,
Thanks for the response. In a nutshell, if I can't be precise and exercise due diligence in designing a sub-woofer system that has the best opportunity to produce quality sound, then I might as well stay with the sub-par stock unit. As an Avionic Installation Master Specialist, I install electronics in aircraft including, but not limited to, complete cockpit instrumentation, Navigation Systems, Flight Management Systems, Traffic Collision Avoidance systems, Emergency Locater Transmitters, GPS, Flight Phones, Weather Radar, FLIR, ADF, SatCom, SatNav, EFIS and yes.....even custom audio and home theater systems on-board corporate jets. As you can imagine, there is very limited room to mount such things as booming bass boxes, so utilizing multiple shallow depth sub-woofers throughout the cabin, often in the sidewall, is the only way to go. As you can imagine, the cabin of an aircraft is many times noisier than our X5's. In spite of this, we provide some pretty stellar results. As stated, subwoofers require a specific sized box to perform as designed. There is a formula you can utilize, when mounting a speaker in a smaller box than designed, whereby you make the speaker perform as if it is in a much larger box by porting. After figuring out the correct length and size of the port, you can add a specific length of tubing inside the box, say 6in. to 18in. depending, and achieve remarkable results. If you have ever looked inside a Bose Wave Radio, they are doing the same thing, but it is cast into the case of the radio. Is this the easiest way to accomplish things...no. Is it the cheapest...no. But since I have the skill set and experience with composite materials and access to them, I might as well give it a try with the stock BMW Sub Enclosure. Other than the Amp and Speaker, it is just my time that will be invested.
Looking at the OE Enclosure, it is a pretty nicely designed unit and with some modification will make a nice location for mounting a 10in. woofer.
Looking at perhaps a JL audio or, if possible, a Boston sub. I will rely on the input of the Audio Specialists at work for choosing Sub and Amplifier.
I guess being in aviation, I am used to working in an area where over designed, over built parameters are a norm. Just OK is never an option, only the best result as possible, within reason, is acceptable. I will post something when I am done.
That said, I have heard nothing but great things about Essam's box and would certainly go that direction if I didn't want to give this a try first and see how it comes out.
I guess I will go ahead and figure out the volume of the OE box and get started.

Thanks again!!!

[carlgo]

Originally Posted by HuskerX5

Carlgo,
Thanks for the response. In a nutshell, if I can't be precise and exercise due diligence in designing a sub-woofer system that has the best opportunity to produce quality sound, then I might as well stay with the sub-par stock unit. As an Avionic Installation Master Specialist, I install electronics in aircraft including, but not limited to, complete cockpit instrumentation, Navigation Systems, Flight Management Systems, Traffic Collision Avoidance systems, Emergency Locater Transmitters, GPS, Flight Phones, Weather Radar, FLIR, ADF, SatCom, SatNav, EFIS and yes.....even custom audio and home theater systems on-board corporate jets. As you can imagine, there is very limited room to mount such things as booming bass boxes, so utilizing multiple shallow depth sub-woofers throughout the cabin, often in the sidewall, is the only way to go. As you can imagine, the cabin of an aircraft is many times noisier than our X5's. In spite of this, we provide some pretty stellar results. As stated, subwoofers require a specific sized box to perform as designed. There is a formula you can utilize, when mounting a speaker in a smaller box than designed, whereby you make the speaker perform as if it is in a much larger box by porting. After figuring out the correct length and size of the port, you can add a specific length of tubing inside the box, say 6in. to 18in. depending, and achieve remarkable results. If you have ever looked inside a Bose Wave Radio, they are doing the same thing, but it is cast into the case of the radio. Is this the easiest way to accomplish things...no. Is it the cheapest...no. But since I have the skill set and experience with composite materials and access to them, I might as well give it a try with the stock BMW Sub Enclosure. Other than the Amp and Speaker, it is just my time that will be invested.
Looking at the OE Enclosure, it is a pretty nicely designed unit and with some modification will make a nice location for mounting a 10in. woofer.
Looking at perhaps a JL audio or, if possible, a Boston sub. I will rely on the input of the Audio Specialists at work for choosing Sub and Amplifier.
I guess being in aviation, I am used to working in an area where over designed, over built parameters are a norm. Just OK is never an option, only the best result as possible, within reason, is acceptable. I will post something when I am done.
That said, I have heard nothing but great things about Essam's box and would certainly go that direction if I didn't want to give this a try first and see how it comes out.
I guess I will go ahead and figure out the volume of the OE box and get started.

Thanks again!!!

You are going deeper into this than I thought when I responded to your post. That is impressive stuff and it is understandable why you would want to work with exactitude! I thought about making home speakers once, but all the calculations about volume and ports and waves and such hurt my head and I ended up buying them...

Porting the little box that would fit into that space is an interesting idea. It might squeeze a bit more out of it and might be efficient enough to not need a separate amp?

I built an Essam box and it is good, but obviously isn't going to thump anyone to death.

[HuskerX5]

Building home speakers is a whole other level....you are often times dealing with complete silence, other than the speakers you just built. That environment will quickly bring out any weaknesses in a persons design. As you eluded, it is just bass, and it is operating in a moving vehicle that is not the quietest, so I will have some room for error. I mostly just want see if I can do it using the OE enclosure. If it doesn't sound quite right, I will just get a sheet of plywood, program the dimensions into our CNC router and mill out some custom panels using Essams design. It sounds like his design is more than adequate, well tested, and anything is better than the OE unit.

I currently have an 8in. Self Powered (200w) Bazooka strapped in the rear for now. It sounds pretty good for what it is, but it is in the way and, like most here, I want a clean and hidden install. I have an Infinity Bass Link in my ///M5 and am very impressed with its depth and power delivery. A very easy unit to install, remote volume control, small package and quite attractive. You can check it out here. Infinity - Car Audio
If it fit in the side compartment, my search would be done.
Got to find some time to get this started before it starts getting warmer or the winter project take a back seat to the warm weather projects...
Don't think I am some techie geek, I am just programmed that way after 27 years in Aviation. You have a great weekend.

[carlgo]

The Essam design is nice. I built one and use it in conjunction with the BSW speakers. It all works together well. It is surprising that a maximum 10" shallow mount woofer in a small sealed box can produce satisfying bass. Again, not enough to scare anyone but good musically. For awhile I had a loose, dangerously loose, fairly big engineered (they said) box with a 12" woofer. It was a little deeper than the Essam unit, but not by much actually. I think the modern woofer designs are simply better than the old ones.

The road noise in my 05 X5 is pretty damn loud. And that is with the entry level Michelins. I would imagine that sport models with big aggressive tires would be even worse. I have to crank up the sound more than I like to actually hear everything.

If music was your passion, more than driving, it would be hard to beat the amazing quietude of Lexus. It really puts a load on their sound systems because you can hear every little nuance, ones that the Xs drown out totally.

I worked in a collision shop and we had to replace damaged speakers now and then. Lexus has huge amazingly complex housings for their drivers, even in the doors. The parts guys at the dealership and I always laughed that they had $10 speakers in these things. It was cheaper to pop out cheap plastic housings than to purchase beautiful exotic speakers like you see from every car stereo retailer. And it worked! The sound is really very nice as you cruise silently along...

[aimtimes100]

i just finished the install however there is a problem...i only get sound from the subwoofer. im getting absolutelty nothing from the other speakers. any idea what went wrong?

[m5james]

Start with the obvious and make sure all factory connections to the amp are fully seated.

[aimtimes100]

double checked everything and read over the manual a few times.at first i thought maybe it has something to do with the fact that i have a dynavin nav, but then i thought if that was the case then i shouldnt be getting sound at all. took another look and found that one ground connection came apart(guess its time to invest in a soldering gun).although i cant say that explains the whole sound from the sub only situation it's the best thing i got right now.taking the trunk apart again tomorrow morning

[aimtimes100]

got everything working today.i must say though Essam Khafagi's write up on how
to make the connections couldn't have been any clearer.very good post