Hi Everybody! I'm new, check out my build

[The Cthulhu 10+ year member]

Well, I'm not really new, I've been lurking around for some time.

I just purchased a BMW 135i about a month ago and think the sound system is so-so. I had a sound system installed in my parents 95 Saturn back in high school, and I've pieced together a sound system for an ex, but my current project goes above and beyond anything I've done with car audio in the past.

I've built a few home audio systems, and my dad, an electrical engineer, has always had a passion for home audio (carver amps and infinity speakers). I've always had great luck when it comes to building a system by the numbers, and I've always preferred SQ over SPL. I'm aware that actually listening to a sound system is what matters, but I'm computer modeling type of guy.

So based on the numbers, reviews, and a lot of lurking around, I've put together the following system for my 135i:

Focal polyglass 130 VR 5.25" (2 speakers) + 2 tweeters (paid $380 w/ tax and shipping from 6th ave electronics)

1 RD Elite 12" 1000 W RMS subwoofer ($350)

1 RD 3250.1 class D mono woofer amp ($425 - with the 2 1.5 ohm VCs in series on the Elite, I should be able to trim the gain so I get 1000 W RMS at volume-knob-max with very low THD)

I've already purchased the above. The 135i has a 6 channel, 10 speaker system. 2 of those speakers are 8" underseat subs that take up 2 channels. Screw them in the forseeable future. That leaves me with the rear speakers, and an interior amp to deal with... I'm thinking:

Interior amp - Focal Solid 4 - 75W RMS/ channel ($400 from crutchfield)

Rear - 6.5" woofer + tweeter ($380, 6th ave elec)

I figure that I can also tack on about $100 more for a 0 gauge sub amp wire and block kit from RD Audio, which puts me up to ~$1200 for now, and ~2100 if I do everything else (xmas time maybe).

If I did the underseat subs, I'd get a low output SQ 2 chan amp and 2 low output 8" low profile subs, I figure it would cost me another $600. But I'm not planning on doing this.

Comments, suggestions, things I'm not accounting for that I will need? A guy I talked to at a sound place wasn't too sure about BMWs, but seemed to think I would need to merge the outputs from my headunit and refilter them. I don't want to speculate too much about this, so maybe someone can fill me in and tell me what I need if I want my above setup to work.

Thanks!

Oh, and please don't flame me for putting a 1000 W RMS subwoofer in this build. I really like precise and loud bass. I listen to everything. That's what a gain knob or variable resistor is for.

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[tRiGgEr 5,000+ posts]

Sounds good, except for the rear fill.

 

[The Cthulhu 10+ year member]

Rear fill meaning those 6.5" Focals I'm contemplating? Any suggestions?

 

[LaserRed38 10+ year member]

Are you installing? Did you listen to the Polyglass speakers? The mid is decent, but I think the tweeter sucks balls. Why'd you get 5.25s for the front stage? You should save up and get some 6.5 K2Ps (incredible speakers but pricey) for the front, throw the 5.25s in back and you'll be good. Anything is possible, you just need to make a baffle. That's if the 135 doors are anything like the 3-Series doors...

 

[davidt487 10+ year member]

Save your self the money and buy the 1750 wire to .75 and you are going to need electical upgrades

 

[LaserRed38 10+ year member]

Does your car have iDrive? If not I would add in a new HU to the mix. The Kenwood 6140/9140s look very nice in the BMW dashes and are very easy to use.

If you have iDrive, I would get an Audison bit one too. It would make integrating and tuning SO much easier for you..

 

[The Cthulhu 10+ year member]

I've got iDrive. Can you give a little more info on the Audison bit one? Is it an equalizer? How much does it cost? I'm still not sure what I'll be doing with the OEM HU signals.

I don't think that 6.5"s will fit in the front, but I have to take the doors off to unscrew the OEM speakers. I'd like to get the 5.25"s in the front and the sub and amp working, and then go up from there.

There's plenty of time to spend more money later. And it's easier to rationalize a few months from now. I only have 2 5.25"s and 2 tweeters + the sub and amp right now. I'm installing everything myself, so I can take measurements. If a 6.5" will fit, maybe I'll get them around xmas and put the old 5.25"s in the rear and set up a 4 channel amp.

 

[LaserRed38 10+ year member]

You can fit 6.5s. Trust me. Anything is possible if you either take the time to do it or pay the bucks for it. But having at least 6.5s up front will give you a lot better midbass. And with that sub you're going to need it.

The Audison bit one is a processor/integration unit. It's uses are pretty much endless. It has aux inputs, iPod inputs, you name it. Every channel has a 31-band EQ so you can tweak everything hooked up to it. It's retail $800 which I consider a bargain for what it does. And all you need is a full range signal from the factory to tap into and you're good to go. Everything is tuned by a laptop, then you can make presets for your different settings and a separate controller can switch them and make minor adjustments.

If you're going to stay passive, I would have just got an Audison LRx5.1k to run your whole system. It's a 5ch amp. 60x2, 160x2 @4ohm + 750x1 @4ohm. The sub channel is also rated 1050 @2ohm, so at 3ohm it would push out enough for your RD sub. But I agree the amp you have now is more than you'll ever use/need for one sub.

 

[DBfan187 5,000+ posts]

where da pics at?

 

[LaserRed38 10+ year member]

Btw coupe or vert? If it's a coupe don't bother with the rear speakers. Buy better fronts and give them more power. Remove the rears to allow the bass to come in from the trunk. I'd return your Polyglass speakers and get the 6.5 K2Ps and run them active up front. Sell your RD amp or return it. Pick up the bit one and LRx5.1k and run the components up front and sub fully active. If you work with computers and have built home audio systems, I trust you'll be able to spend the time tuning the car. Remove the under seat subs too. That would give you a really nice simple system.

 

[tRiGgEr 5,000+ posts]

I hope it's the vert. The coupe looks like a cheap piece of shit

 

[The Cthulhu 10+ year member]

Black Metallic Coupe, red leather interior. Looks better in black than white. White makes the car look like a pregnant cat or something. My last car was an '07 Lotus Exige, so I stopped caring about looks the instant I decided to buy the 135i for its engine... . I'm just happy to be able to hear my sound system over the road and engine, lol.

Anything is possible, but it would be ugly. I have 4" front and rear woofers right now. To accomodate 5.25" I need to go all the way down to by the window switch. I can't go forward much more, because the speaker would be partially blocked when the door closes, and I can't go up, because there's a wood trim hand grip that I don't want to rip off. 5.25" can work, but 6.5" is just a huge stretch. Maybe I could throw decent bandpass midbass speakers under the seats in lieu of the factory subwoofers.

I'm disappointed to hear that people don't think highly of the Focal 5.25" polyglass drivers. They look to be very efficient at 94 db/w, so I'm thinking their output will be more than enough with the factory HU for now. I think that they will also drown out the other speakers because they will have a higher output at the same wattage on the head unit.

 

[The Cthulhu 10+ year member]

I should probably mention that I'm going with a 1.6 cu.ft sealed MDF box for the woofer, hence the higher output. I'm planning on setting the crossover pretty high on the woofer.

I guess the SPL on the Focal polyglass drivers I chose is a little low. I cancelled my order on those until I figure out what I'm going to do. Looking at 5.25" K2Ps right now.

 

[Enellz 10+ year member]

We need pix right now! lol

 

[The Cthulhu 10+ year member]

Nothing is in yet, paid for the amp and woofer, but I'm waiting on RD Audio.

As far as the cars go:

And these are some threads about my Lotus, she is no more //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif :

http://www.lotustalk.com/forums/f157/new-2007-exige-s-70552/

http://www.lotustalk.com/forums/f231/07-exige-s-storm-ti-total-loss-72502/