[akhter]

Ok finally ordered for my march 2010 production 325i with idrive and base stereo (6 speaker/no amp).

Equipment
DLS Reference R4 2-way component 4 inches
DLS Reference RA50 5 channel (4 x 70 W + 1 x 265 W class AB) The amp accepts high level input and has built in crossover. Channel 1/2 can be high and lo passed. channel 3/4 can be high passed and channel 5 can be low passed and has a subsonic filter.
Hifi rear shelf mid+tweeters (I had these from the speaker upgrade in my last car)
BMW OEM window sails

Setup
DLS tweeter tweeter in A pillar using OEM trim for a factory look.
DLS mids in front door
Factory underseats in parallel using 265w sub amp channel
Hifi mids+tweeter in rear shelf (because currently there are no tweeters in rear shelf on 2010 model)

The installer was recommend by the dealer. Paid deposit and ordered the components. Installation in 2 weeks because the OEM trim will have to be ordered from BMW.

According to the amp manual, the subwoofer output is 2 ohm stable. Two 4 ohm subwoofers can be connected in parallel so use the sub channel to power the underseats in parallel. This also allows me to upgrade to SWS or Morel underseats in the future.

Now I have 2 choices:

1) Active crossover the front 2-ways and use the factory head unit to power the rears. Not use the DLS crossover that comes with the fronts.

2) Use the DLS passive crossover and use channel 1/2 for fronts and 3/4 for rears.

Which should I go for? Any other considerations?

[VP Electricity]

Are you recoding the HU?

[808MGuy]

Originally Posted by VP Electricity

Are you recoding the HU?

Plus, aren't the OEM underseats 2 ohms? Wiring them in parallel would give you a 1 ohm load which your amp probably won't care for. Unless the base audio underseats are different from the hi-fi and come in 4 ohm, you might have to wire those in series to get a net 4 ohm load to the amp.

[akhter]

Originally Posted by VP Electricity

Are you recoding the HU?

I am trying to arrange that. If that fails (looks likely) then will have to get a cleansweep to flatten the signal.

[akhter]

Originally Posted by 808MGuy

Plus, aren't the OEM underseats 2 ohms? Wiring them in parallel would give you a 1 ohm load which your amp probably won't care for. Unless the base audio underseats are different from the hi-fi and come in 4 ohm, you might have to wire those in series to get a net 4 ohm load to the amp.

I thought the underseats were 4 ohms:

http://www.e90post.com/forums/showpo...2&postcount=11

Can some confirm this?

According to the manual the sub channel can handle 4 ohm or 2 ohms. Also according to the manual running 2 4ohm subs in parallel is ok.

how should i hook them up?

[kaigoss69]

Originally Posted by 808MGuy

Plus, aren't the OEM underseats 2 ohms? Wiring them in parallel would give you a 1 ohm load which your amp probably won't care for. Unless the base audio underseats are different from the hi-fi and come in 4 ohm, you might have to wire those in series to get a net 4 ohm load to the amp.

Actually, I believe the amp would be fine as long as it did not produce more power than what it is rated for. At 2 ohm, it is rated for 365W. At 1 ohm, it would probably produce a bit more. However, the OEM woofers would probably not even take a third of the rated power before getting destroyed, mechanically and thermally.

[akhter]

Originally Posted by kaigoss69

Actually, I believe the amp would be fine as long as it did not produce more power than what it is rated for. At 2 ohm, it is rated for 365W. At 1 ohm, it would probably produce a bit more. However, the OEM woofers would probably not even take a third of the rated power before getting destroyed, mechanically and thermally.

I won't be playing too loud. Which will be better? Series or parallel?

[kaigoss69]

Originally Posted by akhter

I won't be playing too loud. Which will be better? Series or parallel?

Run it in series. A lot of amps go into protection when the impedance is too low (I didn't of that before). Besides, you will have better range on the gain control in 4 ohm.

[kaishang]

How are you doing the cross-over on the new tweeters in the rear?

[VP Electricity]

I re-read this. Given that you're keeping the OEM 6" speaker (calling it a subwoofer is a terrible misnomer), it doesn't matter what you do. It will sound terrible.

While I like the RA series, I've never used the speaker level input feature. Don't know how it will sound, but I've developed a preference for true balanced inputs and switchable ranges over the years.

And since the underseats have to run to 200-ish, not liking running them in mono.

Why not get an RA40, leave the rears on the deck power, leave the underseats in stereo, and upgrade them?

[akhter]

Originally Posted by VP Electricity

I re-read this. Given that you're keeping the OEM 6" speaker (calling it a subwoofer is a terrible misnomer), it doesn't matter what you do. It will sound terrible.

While I like the RA series, I've never used the speaker level input feature. Don't know how it will sound, but I've developed a preference for true balanced inputs and switchable ranges over the years.

And since the underseats have to run to 200-ish, not liking running them in mono.

Why not get an RA40, leave the rears on the deck power, leave the underseats in stereo, and upgrade them?

Ok, slightly modified plan. By downgrading the amp to the DLS CA51, I was able to add the cleansweep and still keep things in my budget. I ordered technic's harness and was able to get a cleansweep for a reasonable price (initially every place here was asking ~500).

Technic harness -> cleansweep -> CA51 amp

The xover for the fronts will be mounted in the trunk. New wires from the amp to all speakers. This was I can experiment with active xover for the fronts since all the wires are in one place. The CA51 is a slightly less powered version of RA50 (4x50wpc+1x170). also the CA51 will be getting line level RCA output of the cleansweep.

I agree 170ch at 4 ohms while running the underseats in series (or parallel?) is pushing it. In future I plan on getting a sws-8 pair which is the reason for going with a 5ch amp now.

for the rears, I have both the Hifi mids and hifi tweaters with the original tweeter cable that plugs into the mids with the little thing inside the cable. I assume that is some sort of lame xover/filtering/hi-pass circuitry.