I know I have some messages to return to forum members - the combo of a sick kid last week, the short week this week, and the job below all have kept me away from my computer. I will catch up this weekend - promise!
A forum member from NorCal called, was spending the holiday in Seattle, wanted to drop off the 335d for an upgrade and take the train up north.
Car has iDrive, harman/kardon, rear PDC, Bluetooth, no folding rear seat, no skipass.
- Add JBL MS-8 (no permanent installation of the display)
- Retain harman/kardon 2-ohm midrange and tweeter speakers
- Try the moving-a-tweeter-to-the-center-channel mod that kaigoss speaks so highly of
- upgrade the underseat woofers
- add our trunk subwoofer system
- add amplification to power the underseats and the trunk sub
- plan the system with an eye to future upgrades of the front stage
So, we used, in addition to the MS-8:
- A Technic Logic 7 sub harness (we modified it, more on this later)
- An Arc KS125.4 mini Class H amp (75wpc RMS, 125wpc of actual dynamic headroom into a constant load, Class AB with two internal power supply voltage-rail modes, fan-cooled, very small)
- our trunk sub with a Musicar 10" sub (aluminum cone, cast frame, 600W RMS of electrical power capability if needed)
- The EU driver-side trunk quarter panel for CD changer-equipped cars, to give us somewhere to put the MS-8 and the amplifier.
- EQ SWS-8 woofers in our steel adapter rings
Why use a speaker that isn't ranked as a great midbass driver, for midbass? The thinking is as follows - the MS-8 can optimize the speaker response after measuring the actual acoustic performance in the car. The SWS-8 fits, it's pretty durable, and it's in production and warranteed (if a discontinued woofer fails, we can't get a replacement - but we can't tell the client to screw off, either). If the midbass was poor, we would have solved that problem, but as it turned out, it was pretty good. More on this later...
We made a bracket for the tweeter, took it out of its semi-horn mount carefully, and stuck it to our bracket and plugged it into the midrange.
We made a rack for the MS-8 and the 125.4 above the factory amp, and we modified the Technic Top HiFi harness by grafting the MS-8 input and output harnesses onto it as needed.
We got all done and realized that the car had Park Distance Control to the rear! Since we had only used the front and sub outputs of the Top HiFi amp, we weren't getting any tone from the rear to speak of.
So we rewired to dedicate the OEM amp rear door outputs for the rear door mids, and racked the fader forward 100%. This was effective at killing any sound coming from the rear door speakers, EXCEPT for the PDC chime.
It also slightly - but noticeably - reduced the bass from the OEM amp. So we recalibrated after making the change. That got the bass back where we wanted it.
After calibration and listening, as we've done before, we reduced the center-channel output level to almost minimum - without cutting the center level, the center overpowers the fronts and it sounds like mono.
We set the MS-8 output level to maximum. This kept us out of trouble with the inputs clipping, since it got louder than we ever needed it to get, so we never heard the Top HiFi sub channels clip the MS-8 inputs.
We set the trunk sub to 50 and down, the midbass from 250 down to the trunk sub, and the center and rear from 350 and up.
We also added some EQ boost between 80 and 200, and brought up the sub level a couple of clicks on the MS-8 (this boosts both the sub output and the bottom end of the midbass speaker).
I've spent some time listening to various songs today in the car. I don't listen to hip-hop much. I listen to jazz, singer-songwriters, female singers, some rock, and Lyle Lovett.
Clark Terry, Live at the Village Gate, sounded great - clear positioning of the voices in the club, good room noise.
Jennifer Warnes, The Hunter, sounded great - Way Down Deep has some notes that ONLY exercised the sub.
Corinne Bailey Rae's Choux Pastry Heart has bass notes that are audible as a heartbeat only on systems with really clear, tight bass. Check.
Icky Thump by The White Stripes has a good tight thump to it, without overhang or boominess. This song does show the limitations of using a 75x2/250x1 amp on the bass - you could get more.
Focus on Sight by Thievery Corporation is similar - tight bass, not boomy, extends much deeper than stock, but if you want to really lean on it, you could use more power than we had (and that would outrun the MS-8's internal deck-power amp ICs pretty readily, I suspect).
The HK speakers sound a little thin at times, and the tweeters get a little bright (I cut a bit at 2k on the EQ and that helped). The customer wants to upgrade the front speakers in future and add an amp, so I am recommending getting a mono subwoofer amp, and using that half of the current 4-channel amp on the front components.
We coiled up the display cable and the display and put them under the pop-out plastic tray on the quarter panel. We also velcroed the remote to the inside of the CD-changer door. This allows the customer to open the door, grab the remote, reach under the tray through the door and pop the tray out, pull out the display and cord, and tweak the system.
It's certainly not a perfect system, but it's got real bottom-octave extension compared to stock, it's louder than stock and clearer, the imaging is very good, and it is 100% reversible!
Thanks to Technic for the harness and to the customer for the chance to do the install.