cvjoint

Caution, this thread contains lots and lots of 1mb pictures!


This build is a pure scientific application.

Problem: Maximize output while minimizing distortion such that the following constraints are met:

1. no component hinders the driving experience
2. trunk and cabin room remains unchanged
3. budget < $3,000
4. time from start to finish < 100 hours
5. weight gain <100lbs
6. current draw < oem alternator capacity (105amps)
7. car can be returned to OEM state
8. 80% removable in under 5 minutes for track use
9. stealth when parked for safety
10. sources: GPS, Bluetooth Audio, USB, MP3 CD, Radio, Aux
11. decent soundstage
12. reliable


The car is a pristine condition early model S2000. I got it in March 2010 with less than 20,000 miles. I like it for its raw nature, no floppy paddle gearbox, no traction control, no seat warmers, just lightweight, open air and free revving.

Stock pictures:
2010 @ Streets of Willow Raceway















Stock speaker system, in it's entirety:



Here is the list of all parts over $25:

Pioneer P99 Headunit $950 NEW
Pioneer Bluetooth adapter $150 NEW
Clarion XH7110 Monoblock amplifier $180 Slightly USED
Clarion XH5410 4 channel amplifier $160 Slightly USED x2
B&C 6ndl44 7" midbass $110 NEW x2
AE IB12A-8 Subwoofer $110 NEW x3
BH NEO8 $70 NEW x2
Vifa NE19VTS $25 NEW x2
Resin $30
Fiberglass $40
Birch Plywood $35
Leather wrapping job for pillar pods $150
Monster Cable RCA $45
Ensolite $50
Ramat $30
Carpet $25
Anderson Powerpole connectors $45
Modifry IR adaptor $80

Total $2870 + cheap items, constraint number 3 satisfied!


Completed project pictures:

Passenger side pillar pod with tweeter+suppertweeter



Passenger side midbass



Driver side pod



Driver side midbass:














That's it for now.

aphex4000

Wow! That is some serious home theater quality stuff there. It sure would be nice to hear it in person. Great work!

brooklyns2k

wow thats sick!!!!

cvjoint

Thanks! I can demo the car for anybody in so. cal. that goes to local meets. Otherwise, I'll post a decent amount of tests I've done, linear and nonlinear distortion, cabin gain tests, bass decay and reverb etc. Next up I'll post a how-to for the infinite baffle subwoofer install.

Ragnarok043

nice, ill be installing the P99RS in my S2000 as well, how are you liking it so far. i also noticed you went for the modifry IR adapter instead of the wired, any particular reason.

cvjoint

Oh, nice! What other gear will you be running?

I started out with a used Eclipse CD7200 MKII headunit. That one only worked IR with the Modifry. I kinda got stuck with the IR, but the Pioneer can do wired. Maybe one day I'll change it out, but I'm too lazy and I completely forget the sensor is there.

The P99 is the best single din choice bar none. The sound quality is supreme, mainly due to the quality of the components they installed in this one. The Eclipse used to pick up noise a lot and clip easily, even on tweeters. This thing is worlds away in performance.

There are however many many ways to improve the headunit:
*31band EQ. is weak. I had a 64 band parametric with my carputer.
*You can't EQ speakers separately, just left and right.
*Filters are Butterworth. This is weaksauce, give me Linkwitz Rilley
*no linear phase filters (distortionless EQ.)
*Bluetooth adaptor is adequate. Takes too long to connect and sometimes it just won't work for no reason.
*in a larger car you may want the MS8 for the simulated surround.
*radio reception is blah. I love NPR

cvjoint

The subwoofer/amp setup

The enclosure design is infinite baffle. The idea is stolen from home audio, where guys have been setting up their attics to act as an oversize subwoofer enclosure. The ideas behind this design are so illuminating it truly created a cult-like following: "Cult of the Infinitely Baffled"Hear The Bass, Not The Box The definitive online resource for Infinite Baffle subwoofer designEstablished 1999 - Home

In a car there really isn't enough room anywhere to truly get "infinite" airspace. Generally you need 10x VAS to get the real thing. My 5ft3 trunk barely provides adequate room for the three 12"s. The resulting Q is .7. What is the benefit then? The benefit is that I get to use the entire trunk space as a subwoofer box. It sounds ideal empty, and ok when filled with grocery bags. Without the infinite baffle arrangement I could never give three 12"s enough room to breathe.

A second benefit lies in the weight savings. Instead of fiberglassing a big 5ft3 box I only had to fiberglass about 1/3 of it. The rest of the box is the actual trunk sheet metal. On top of the box savings the subwoofers used in this arrangements are also lighter. Big box subwoofers do not need huge motors/magnets to push the cone against a small box's air. The IB12s I'm using weigh just 15lbs a piece. Here are all three subs weighed with the removable baffle:




This baffle screws into a fiberglass cage that together with the trunk walls provide an enclosure. Total weight is 60lbs or so total. The baffle you see in the picture is three 3/4 birch sheets screwed and glued together. I had to countersink one of the subs to make all three clear the trunk lid support arms.





The baffle mounts with 4 roof construction self tapping screws straight into the fiberglass cage. Here is what the cage looks like in the car:







The cage has two purposes. One is to hold the removable baffle. That means it has to be strong. It is at least 7 layers of fiberglass cloth and it is held with bolts against the chassis. Further support comes from the pressure fitment. The cage does not come out of the car easily as it has dampening layers over it and carpet. Lastly together with the aluminum butyl dampening sheets it seals the trunk from the interior of the car when the baffle is bolted in. Here is the final look without the baffle attached:



Behind the subs, where the spare used to go, I installed the amp rack. The amp rack is hooked up to the car wiring with quick disconnects. It is held in place by pressure fitment and one wing nut. It holds three full size Clarion amplifiers for a total of 1,500w continuous. It holds power splitters as well for a combined total weight of 35lbs:



Removed from the car:




Benefits of this design:
*Sub baffle and amplifier rack are removable in <3 minutes(good for track days)
*Sturdy design, no movement whatsoever even under high G forces (rattles minimized)
*Combined sub+amp arrangement is <100lbs
*Combined net weight after spare and toolbox removal <70lbs
*Net trunk space lost after spare and toolbox removal 0 ft3.
*All the weight is directly over the rear axle
*Weight location mimics spare and toolbox distribution
*Easy to service, and tweak
*Great low end extension with 5ft3 available, all the way down to 20hz
*Great output with 3 twelves, will handle 1200w or so continuous
*Waterproof (cones are treated, amps are hidden)
*Great cooling (amplifiers are in the cabin side)
*Back wave vents to the cabin through a 3ft x 1ft opening under the softop (little excursion noise, rattles, and output is amazing)

Drawbacks:
*Exposed cones can get dented (thinking of grille idea, ideas welcomed)
*Subwoofer back wave can be free-er if the amplifiers were located somewhere else (not sure it would be noticeable)
*Can't make quick amplifier adjustments (however, all filters are bypassed, gains are maxed out on the low setting, up front bass gain installed, the rest is done in the headunit which is very easily accessible)
*Can't forget top down on a rainy day or amplifiers get soaked
*I had to remove trunk springs, so the lid cannot hold itself open (I'm thinking of installing trunk shocks)

I have even more detailed build pictures that will be discussed at some point.


Thanks for viewing!

Ragnarok043

ill be running Focal KRX3 with a McIntosh MCC406M and a JL10W6V2 with a JL500/1, so far im almost done with the sub enclosure. heres my build thread.

https://www.s2ki.com/s2000/topic/863168-system-install/

vactor

in for more info and pics. just got my S2k and planning my system. thanks.

cvjoint

You got it!

First I'm going to finish off the driver choice ideas for the subwoofer and then I'll go into the door build for the midbass drivers.

Acoustic Elegance IB12-A8
These were the best choice that I could find for my car for several reasons. The goal here was to find three 12"s that have loads of output and low distortion while weighing as little as possible and use a basket and magnet assembly that fits between the chassis, soft top mechanism and allows the amplifiers to get mounted there as well.


We had Matt @ ID Klippel test these drivers here:
http://www.diymobileaudio.com/forum/...-ib12-8-a.html

The biggest design advantage of the AE speakers are of course the full copper sleve on the motor. This is a patented design as far as I know, and for good reasons. The benefit is low inductance, which in turn gives more useful bandwidth (good up to 1,000hz I would think), and low intermodular distortion. On this second point I must stop and elaborate on one myth, that subwoofer distortion is not that important. Say we generate a test tone of 50hz. If the subwoofer has lots of resonance and IMD harmonics will be generated that are well within our audible range. 2nd order distortion for this tone will occur at 100hz, 3rd at 150hz etc. The fourth harmonic will be very audible if loud enough. The thing is, in most cars subwoofers are set to play at much higher output than the rest of the speakers. That 4th order harmonic at 200hz will be loud and very noticeable. The lambda motor and low resonance parts used these AE subs are very low distortion.

Second the motor is superb. BL looks better the Peerless XXLS, a long time reference, and slightly better than the Dayton RS. I could probably count on my fingers the subwoofers out there that have a flatter BL than this, and most of them weigh 30lbs+ which is at least twice as much.

The B&C 6ndl44

The pictures at the supplier are much better than I can take:
B&C 6NDL44 6-1/2" Neodymium Woofer

This is an older version of the 6ndl38. The only difference that I could find on them is that my version has more output capability, lower sensitivity (.5db) but given 50w RMS more it more than makes up for it (1db louder). Net gain is .5db, and they were $30 cheaper to boot.

Based on my modeling and research this is the ultimate 7" 80hz-5,000hz. What I mean by that is that it has the most output and the lowest distortion over that range. There are however better choices for a 7" used 80hz and bellow, like the CSS SDX7, the EXODUS 7" and Peerless SLS 7". None of them fit in an S2000 and I don't see the point of crossing 7"s that low anyway, they have almost no usable output. In fact I use mine 100hz and up with a very steep slope.

It's 8" brother was Klippel tested as well:
http://www.diymobileaudio.com/forum/...l51-8-8-a.html

This is using the best engineering there is out there and makes all the right tradeoffs. I think the shorting ring in this one is a bit basic but an upgrade will produce a minor improvement I would think. On the Klippel, it's one of the few speakers in production that has a legitimate Xmax claim. The only 7" that comes close to this is the 18Sound 7". It seems hard to get in the U.S. and the xmax is not as good. Even the physical basket clearance is smaller, which means less xmech.



Fitment in the S2000
A bit of a pain, but manageable. My S2000 came with 6.25" full range drivers:



Here is the door panel:


The full documentation on what this car can fit, and naked pictures are here:
http://www.diymobileaudio.com/forum/...nk-2010-a.html

Fiberglass baffle
I simply fiberglassed over the stock door as it is, with the plastic spacer from factory. This means that my mold would be larger than the spacer, yet centered properly to clear the door panel. While I could have made a tiny one, I had a much larger "L" shaped mold design in mind. When held in place with metal screws, this large baffle has much more structural support than your average MDF spacer. Since it grips on a wide area over the sheet metal it rattles the door mechanisms a lot less. Initially I wanted to fiberglass the whole inner door skin but I came to the conclusion that it would provide very little extra support and may impede the panel from fitting back on.

1. Use the good quality glass painter's tape, always:



2. Fiberglass over a larger area then intended, you can always trim excess fiberglass later:


3. Remove mold. Trim excess fiberglass. Remove stock plastic spacer. Use fence cutting scissors to slice the door sheet metal. This last step is needed since the B&C speaker has a big basket. Additionally every good install allows for a lot of airflow behind a speaker, so don't be stingy and slice it. That inner metal is not the safety piece for the car. Bend the slices of metal in. To return to OEM years later just bend them back and mount the plastic spacer on it. Add dynamat before that if you want it to be as stiff or stiffer than oem. Use metal screws to bolt the mold to the car sheet metal. Add deadner over the mold, the sliced sheet metal and into the door. You want the back wave of the speaker to vent inside the door, not behind the door panel. Many things going on here and I only have one picture but this is a <100 hour project remember.



4. Add your deadner of choice to isolate the front wave from the back wave of the speaker. This means cover all the holes as long as it doesn't impede door operation. Isolating the two waves will give you less cancellation - more output. The deadner also strengthens the baffle, again giving you more output. Finally it reduces rattles and road noise, both very good things. I only add a layer, consequent layers do nothing other than reduce roadnoise if your fiberglass baffle is large enough.



5. The window stopper mounted on the glass did not require any trimming. Say thank you to B&C for investing lots of resources to design that small and brutish neo magnet. You do however have to trim the door panel on the inside. The trick is to remove only what is needed. Leave the rest of the plastic to maintain some door structural support. That way if you kick the door getting out it wont break in.



Note how much of the front wave is blocked by that screw right in the middle. Because of that, and other reasons I recommend you restrict the upper response of the speaker as much as possible. I use mine only up to 1,600hz. The pillar pods take over from there, those are completely urestricted. Another downside to putting a door panel over the speaker is that a lot of the front wave will bet stuck between the door and panel. There will be resonance. If you are hardcore fiberglass the panel itself and mount the speaker over it. That's what I did in my much higher budget and time expense Accord:
http://www.diymobileaudio.com/forum/329601-post167.html

6. Wrap the inside of the door panel in Ensolite. This will absorb the front wave that gets trapped in the door panel to some extent. It will also prevent the panel from rattling. I haven't done this yet, ran out of budgeted time, but I have no rattles.

Window rolls down no problem. I have no water damage to report. The suckers pound. I have used them up to 5khz, they sounded ok.