Fiinally..almost Done: Full System Upgrade Keeping Navi Head Unit

[elerner61]

So this has been a nice, long project. My goal was to do an extensive upgrade of the Top Hifi with Navigation system in my roadster and play with some new car audio technology while still keeping the stock Head Unit and Navi. The new technology in this case is a Digital Signal Processor from JBL called the MS-8.

I used the MS-8 for a couple of reasons. To get around the limitations of the stock Top Hifi amp, it's idea of equalization for the car and restrictions on what speakers (impedance wise) can be used I would need some sort of line output converter to get a clean signal for my "clean sheet" system. My bare minimum requirements were a clean signal and the ability to use the volume control on the OEM head unit. From my research, only JBL, Audison and Alpine units would fill these needs. In the end I went with the MS-8 because it doesn't seem to require extensive (or even much) audio tuning experience. I didn't want to have to start using a real time analyzer to finish the tune (actually that would have been cool, I just no where near have the time). These units do much more than just line output conversion. To briefly summarize, they provide full control of active crossovers for your drivers and amps and tune/equalize/time align your system to your car using an in-car microphone. There's a 270+ page forum thread on the MS-8 that's followed it from development to now (5 yrs).

The project was done in 3 phases:
1. Insert the MS-8 into the bone stock system, running the stock drivers off the amps in the MS-8. No subs; no way those funky oem drivers can run off a non-oem amp. No behind seat mid drivers; those are just silly
2. Swap out the oem drivers for something better, yet still run off the amps in the MS-8 (20 watts/channel)
3. Add an external amp
4. Add subs

One unknown with this project is that my stock subs emitted relatively little sound . Either the stock amp section for the subs is blown (likely and common) or that's how they really sound. I was able to isolate the subs during the phase 1 when they were the only OEM drivers I still had connected to the OEM amp. Strangely, when I faded the HU to the rear there was very little output from the subs. When I faded to the fronts, the subs did play but mostly when the HU volume was medium and higher. Anyway, the "unknown" is that since I thought my sub amp was blown how would I get sub frequencies into the MS-8 as part of my clean signal. I took a gamble that the signal to the front mid-bass (woofers) was not hi-passed and actually had all the low end frequencies I needed. That ended up to be true. I'm only running with signals from the tweets, mids and mid-bass' as my inputs to the MS-8

So...how did it sound?

Phase I: MS-8 Insertion
Wow! A totally new system. The MS-8 tune/time alignment takes a little getting used to in that it creates a front and center sound stage in the middle of the dash board for the vocals. Plenty of volume though and the stock drivers don't sound half bad. Yeah the tweets do still sound kind of harsh, but the mid-bass' have a pretty good bottom end and their 2 ohm resistance doesn't seem to bother the MS-8 amps. They are sometimes boomy, but overall not bad

Phase II: Swap out new drivers- CDT HD 3-way drivers
Unfortunately the limited depth (around 2") of the stock mid's in the doors kept me from installing 4" replacements. I had a 2-way CDT HD set and I picked up a set of ES-3 mid's to use in the doors. Of the three drivers, the mid-bass in the kick panels were drop-ins with only new holes needing to be drilled. To hold the 3" mids in place I fashioned a particle board mount that holds them from behind and the DRT-25 tweets were a tight fit but some plastic nipping here and there did the trick. And the sound....now we're talking! Much smoother across the entire range. No more metallic sounding high end. The bottom end doesn't hit as hard as the OEM drivers, but it's not boomy at all.

Phase 3: Add external amp
I picked up a Class D, 5 channel ARC XDI 805 for a steal of a price. Can't believe how compact it is. And the sound... HOLY CRAP! I forgot how much good amplification does to the bottom end of a system. Can't believe how solid those mid-bass' hit now. I've been using "Aja" from Steely Dan as my initial test cut during the upgrade and now it has really come alive!

Phase 4: Add Subs
Yes folks, the JL 6W6V3 6.5" subs will fit into the stock locations. There is suitable depth for them, no need for a ring behind the drivers to lift them. One tricky part is drilling new mounting holes for the JL drivers. The front of the sub enclosure is closely contoured to the OEM sub driver mounting holes. And the stock grill will fit just fine if you trim two sides of the inside "grill/guide" (a Dremel makes quick work of this). I pulled the stock cushioning and installed sound deadening (RAAMmat). How does it sound? Almost great! I'm still tuning this. It's my first foray working with subs and figuring out where to cross the mid-bass in the fronts with the subs is my current challenge. I started with 80hz and a 24db/oct slope, but that took out the mid-bass in the fronts too much. I'm now crossing at 60hz with a 12db/oct slope and it sounds much better. The ARC amp. has an external sub volume control that I've mounted behind the passenger seat that's really great for on-the-fly adjustment. I'm going to add some fiberfill to the sub enclosures (I think they sound a little harsh still at times, I can sometimes hear them as well as feel them, could be they're still breaking in). But it's amazing to be able to hear and feel the picking of a standup bass on certain songs.

Here are some pictures of the instal (they're a little large, but actually show detail nicely). It's been a real interesting project and I've still got some cable dressing and tuning to finish up!

[gferil]

Very nice, I've been waiting to hear your review of this. Can't wait to hear the updates once you're 100% and have time to tune everything.

I'm probably going to add those same subs to my system, so thanks for confirming the fit and good sound!

[elerner61]

From my experience so far, if you listen to a wide variety of music! an in car, easy to reach level control for the subs is a must. I'll play some R&B or my son will get in the car and play some hip-hop and its produced with so much more emphasis on the bottom end than the rock, jazz or blues that I mostly listen to that I have to tone down the subs. Now, I may have some peaks and other things to tune out of the subs and sub/mid cross config. But I can see why so many amps have a remote sub gain control as an option or come supplied with one .

[Bayonet]

nicely done...i have the same amp....arc's size and performance go perfect in our vehicles

[ZStig]

cool stuff!

[Beedub]

that is very cool !! love that you did this keeping the stock head unit......

[RancidFerret]

I was wondering... how difficult do you think it would be to fit the 8w3v3 in there? Its mounting depth is only .38" more than the 6w3v3. Was there any room left behind the woofers when you installed them?

The 8w3v3 is also 1.69" greater in diameter and based on your pictures it looks like the ring with the mounting holes would have to be cut to make it fit...

Anyway, I just wanted to see what your thoughts on this would be. Thanks and great job on the install!

[elerner61]

Sorry, was on vacation and unplugged!

I don't think the 8's will fit. There is a lip on the front face of the enclosure that will restrict the larger diameter of the driver. I had my first driver all mounted on the front panel, and when I tried to secure the front panel to the enclosure the lip was hitting the back of one of my mounting screws. I had to re-drill new holes in the front panel keeping in mind the restriction of the face of the enclosure.

[Denton]

Thanks for the thread but my bank account is feeling a bit of pressure now!

[tmoody]

let us know how the setup sounds.....i was planning a trip to the local A/V to talk about a Dynaudio setup

[elerner61]

Originally Posted by tmoody

let us know how the setup sounds.....i was planning a trip to the local A/V to talk about a Dynaudio setup

To be honest, when the program content is very dynamic with lots of detail the JBL-MS8 experience is amazing. When the content is not (such as badly engineered '70's content) it's a bit of a letdown because it sounds so great otherwise. The subs seem to have broken in over the past month or so and don't hit as harsh on some content as they used to. I still have some fiberfill to add to see if it can calm down some peaks I've got (the very beginnning of Pink Floyd's Wish You Were Here, with that rhythmic very low frequency tone drives them a little crazy if they're turned up).

What are your thoughts/plans? Do you have Navi?

[tmoody]

i do have the NAV unit in the car. I'm looking at what Dynaudio speakers I will need, first, then will work backwards to what will be needed to upgrading the amp(s).

[nadaclue]

Are you using at least one of the passive x-overs on the 3-way set up front? Otherwise how are you doing a 3-way active x-over off the arc amp? Are you feeding the internal MS-8 amp to the tweets?

At one point I had tried putting 8" subs behind the seats, the problem I had was the size of the basket hitting on the top and bottom of the cutout. I had made 3/4" MDF boards to replace the steel ones that the original 6.5" subs are mounted on. I'm sure there are some 8" subs out there with smaller baskets, I just didn't pursue it any further.

The downfall to the 8" on the 3/4" board is that the stock speaker covers will not fit. I had also dynamat and silicone sealed the factory locations, it really cut down on some annoying ringing.

I'm honestly still tempted to rip it all out and just port some 10"s from the trunk into the cabin area through the factory speaker locations behind the seat. I just haven't gathered up the stones to cut holes in the sheet metal to feed the ports through.

[losingmylycosa]

Would the Coupe's need porting (if putting a 10" in the back) since they are open space back there?

Any updates, Elerner61, things you might do differently?

[Kream]

Do you hear any buzzing/charge noise from the battery with the aftermarket amp?

I heard it with my setup when I'm idle but once the car starts moving its gone. Thinking its amp draining the battery.

[elerner61]

So a little update on my MS-8 based system. After having the MS-8 control all 4 driver sets for a year and a half now, I've noticed more and more that (as a number of MS-8 users have) that I'm missing too much mid-bass. This is mostly noticed at comfortable listening levels when your ear is looking for some bass riffs, such as in some Blues tunes that you know are there. This has to do with how the MS-8 does it's equalization for the sub/mid-bass crossover. One way to fix this is to calibrate the MS-8 in 3-way mode without the subs and then after calibration split the mid-bass out of the MS-8 (as in with RCA-"Y" adapter) add the subs and then control the mid-bass/sub crosssover on the external amplifier. I've done this and I've got my mid-bass back (big hurray!). I've been on some comfortable topdown cruises lately and feeling the bottom end without having to crank up the volume is fantastic.

One problem is that this is a fine edge. Some content is produced with more of a heavy hand on the bottom end than others. Since I can't use the tone controls on the head-end to easily trim some of this (a plus in the "replace the head-unit" column when thinking about updating a system) and reaching for a different EQ preset on the MS-8 while driving is difficult since it's tucked away in the center console, this presents a challenge. I've recently learned more about how the remote sub-level control on my amp actually works (Arc Audio XDI-805). Instead of adjusting the level across ALL sub frequencies it actually adjusts the level at a controllable "bass boost" frequency. I'll be playing around with this over the weekend as well as maybe closing off the sub port. Fun, fun, fun...

Oh, and to the earlier poster who asked but never got an answer; I'm running the tweets off of the MS-8's internal amp, the mids and mid-bass and subs are off of the XDI-805. The internal amp on the tweets has never run out of legs and limited the output of the system.

[funkle]

Thanks for the update. Cant wait to get my audio system sounding good.

[elerner61]

Ok, this could be "the wrap up" post. I've just about got my MS-8 based system tuned up.

To kill the subsonic issues I was having with the JL subs I installed a 30hz Harrison Labs inline filter and that worked very well. I then set about tuning with the subs disconnected first, and then connected the subs and disconnected the midbass. With only the subs playing, I was still underwhelmed with their sound (still popping and very little output). I was about to close off the vents in the enclosures but was still concerned mostly about the lack of output. I had the low pass x-over on my amp (Arc Audio 805) set to approx 70 hz and started to adjust the bass boost frequency and level settings on the amp. That had very little effect. As a last ditch effort I decided to see what raising the low pass x-over would do. That was it! What ever the reason (my lack of knowledge, amp issue...) once I raised the low pass the subs started playing real nicely. From there I dialed it in and then worked on the JBL-MS8 equalizer bands.

In the end I came to the conclusion that of the three sound sources I use in my system (head-end radio tuner, iPod, iPhone-Spotify) the tuner and iPhone-Spotify have boosted bottom ends compared with the iPod. I saved three equalizer setting favorites on the MS-8 to switch between for the different sources. I'm real pleased with how it sounds. Very cool to really hear and feel ALL of the music now, even (especially) when running top down.

I'm still on the fence about not closing off the sub vents. For R&B and similar music they play pretty low and sound very nice! but for Rock, Jazz and Funk/Soul they're a little muddy. I'll probably close them off one Saturday when looking for a project and see how they sound.

Damn, what am I going to work on now?

[DaveJB]

I hate to dredge this up but you make no mention of how/what/which wires to use for inputs. I am currently looking for a DSP and am wondering how many speaker level (and WHICH ones) inputs I'll need for a full range signal. Thanks!

[elerner61]

I used the front speakers (tweets, mids, lows) and the subs.

[DaveJB]

Thanks for the quick reply, but... can you elaborate? I don't have the car apart yet so I don't know what it looks like back there. Are you saying you took the output after the amp, to the speakers? And it sound like you're saying I'll need a processor that has 4 stereo channels of input? So, 8 total?

I was wondering/hoping if there was a simple stereo input going into the amp.

[elerner61]

The system installed in my car is referred to as the Top Hifi configuration with Nav. From my research I discovered that the head unit sends a digital signal to the amplifier to control the volume. There is a analog signal from the head unit to the amplifier, but if I had used that I would not have any volume control. Since I wanted (had to really, because of the Nav) keep the head unit, I had to use the speaker level outputs from the stock amplifier. The Top Hifi system amplifier has four different drivers to cover the frequency spectrum.

You need to confirm which stereo configuration you have in your car and then determine where you can get a full frequency spectrum signal. Search the web for info on the different Z4 stereo configurations. I'll try and dig up some reference links I may have.