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      11-08-2012, 09:09 AM   #1
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Drives: 2015 320i
Join Date: Apr 2005
Location: Ft Lauderdale, Florida

iTrader: (18)

Notes on a 2011 335is with Stereo (6-speaker) system with a Zapco DC/RF P300 amps

Customer made extensive searches in these forums for the most "bang for the buck" upgrade for his 335is disgraceful Stereo system. Then he goes to eBay for a cheap shopping spree after finding out what he needed:

- Focal 100VRS component set (used, in pieces)
- SWS-8Xi (new)
- Zapco DC200.2 (used)
- RF P300-2 (new)

Then he shows up for the install...

Comparison (left to right) between the OEM, the 100VRS and the DLS R4 mids depth:

Front door mid install:

100VRS crossover install (frame removed so it can fit in the E92 door panel) and PnP harness:

OEM tweeter pods installed with VRS oversize tweeter:

Underseat OEM 6.5" woofers replacement:

Pre-mounted SWS-8Xi with OEM woofer connector/spacer (full PnP):

Stereo 2/4 PnP harness installed (no OEM HU removal required):

OEM carpet trimmed to avoid contact with the extended-excursion SWS-8Xi:

RF P300-2 (for the SWS-8Xi) and Navone LOC (low level conversion and remote turn on) installed:

Zapco DC200.2 installed under rear deck:

OEM distribution block double slot available:


- This was a very particular Stereo install, as in using a DSP (Zapco DC) only for the front speakers, a bass-boost EQ amp for the SWS-8Xi and OEM HU-powered rear speakers. Results: quite satisfying.

- DC200.2 amp/DSP was tuned to remove the slight OEM HU EQ-curve, to maximize volume while keeping the "gongs" as close to OEM levels as before the amp upgrade. Most of the Stereo amp installs make the gongs volume excessive, and the only way to keep it down to bearable levels is to set the amp gains as minumum as possible. But that kills the volume of the front speakers.

By using the AudioTools iPhone RTA app and the Autosound 2000 test CD white noise track, the OEM HU EQ-curve that tended to boost treble was reversed but with a midbass slight boost with the DC DSP controls. Then the DC electronic gain was set to level the gongs in specific. To finish this up, time alignment was done as well.

This gave an excellent front stage, volume range and clarity. No hiss, no whine. I really liked it.

- The P300-2 is a great, low cost amplifier for the SWS-8Xi (2ohms). No need to adjust gains, just the Punch EQ bass boost. Again, there is no substitute for the ultimate "boom, boom" without a sub than the SWS-8. Midbass is slightly lacking, no matter how much it was boosted at the 100VRS mids via the DC. However, between a high LP filter (200Hz) and Punch EQ relatively high level settings some midbass was artificially increased.

Overall, this was a very smart upgrade from a customer. No unnecessary devices, wiring or disassembly were performed. Just what was required for an effective sound upgrade. And it worked.

Last edited by Technic; 11-08-2012 at 10:23 AM.