2001 Accord EX Sedan - it's long

[keep_hope_alive]

trunk side (the factory panels will be replaced sometime in the near future
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I have my back seat again! And the view from inside is nice
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the first baffle to accept two OZ-300H 12" subs is shown here, but as i'm typing this, the first coat of resin is curing... all holes drilled, t-nuts added, etc. But this is the pattern:
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The subs will be mounted with the magnets on the cabin side - for two reasons. 1. i love the look of the cones in the trunk - it's just classic. 2. it saves more space that way, and i also like the look of the magnets - but only when i fold the seat down. I love it when a project comes together.

baffle coated in resin, ready to carpet.:
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10-24 t-nuts for the dub mounting
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closed cell foam around the opening for the IB wall
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the 1/4-20 mounting bolts, need the length for the multiple 3/4" MDF layers and foam and fiberglass, and filler, and deadener, and carpet...
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waffle grills are ugly - but functional. i need some nice grills
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[keep_hope_alive]

this turned out much better than expected (dispite being made from many pieces of carpet...
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making the sub speaker cables:

solder is your friend
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heat shrink is your friend
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split loom is also your friend
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secured to the subs
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[keep_hope_alive]

the trunk needed some final trim panel fabrication, but it's fully functional and sounds great. and you can tell i had a lot of carpet seams, and just pieces covering seams and wires. the final result will have a minimum number of seams and look much nicer than this. RTA analysis to follow:

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the false floor doesn't fit as i want anymore (too deep), i'll need to make a new one
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i also need to re-run the RCA's after I make custom ones. I may relocate the 3300c and H701 to the passenger side, allowing for a spare tire again. if that happens, i'll just fabricate both amp mounts from scratch so i have better access to the tail lights (a bit cramped now)
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made a new floor out of 1/2" MDF, then coated it in resin to help waterproof it
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and i painted the bolt heads black - using Testors Black paint
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[keep_hope_alive]

constant work in progress. at this point i am experimenting and learning a lot along the way.

some recent rear door deadening for road noise reduction (sealing door). each door took about 20 minutes. I used Raammat BXT on them.
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driver side
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split loom to let cables pass through
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5[/quote] [quote=keep_hope_alive]i finally rebuilt the flush covers around my side amps, this was a long time coming.

i haven't made any sub grills yet, still rockin' the 80's waffle grills. they protect the subs, that's the #1 goal. cosmetics will come over time.

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---------- Post added at 01:46 PM ---------- Previous post was at 01:45 PM ----------

i also tossed in some rear speakers, re-deadened the rear deck and resealed them. the speakers are in a small sealed cavity. nothing special, i'm trying to decide if i like them like this, or if i need to rebuild the entire rear deck (likely). they are ran off the center output on the H701, 3CH PCM, bandpassed, and delayed. they did help push the sound stage out more and increased some overall definition. if i get a config i like i'll upgrade the drivers.

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i also installed a new pin switch and two white LED strips for trunk lighting. they work well.

nothing is private with this build, it's a learning experiment.

crossover points varied (as did slopes) but were normally at 315Hz and usually 24dB/oct. I also ran it as high as 500Hz - but the 1/2 wavelength associated with the cone separation started to cause issues. Below 315Hz I could hear upper midrange break-up at higher volumes. With a 7" separation of voice coils, the 1/2 wavelength is 328Hz. I wanted a 5kHz mid/tweeter crossover point, but output was lacking above 3kHz from that mid off-axis. I understand that imaging cues are intensity based above 4kHz or so, but I still want representation in both ears.

the phasing issue, i think, is due to the difference in driver separation relative to each seat, and interaction between the pressure waves. I have back wave separation in this build, so that's not an issue. Lower crossover points seem to help, but my 4" reaches a low end limit.

my goal has been a two-seat car, without a center channel. some days i'm close, other days i'm far off. i'm constantly tweaking, saving presets, going back, etc. after the RTA sessions my adjustments are phase, TA, and crossover.

more importantly, the HF roll off of the 4" off axis was also an issue. I want to move the 4" where the 6.5" is, and move the 6.5" to sealed FG enclosures on the door (with driver as low and far as possible). redoing the carpet will coincide with that effort.

currently, i have the 4" off. I am running the Oz 6.5" in the floor as the mid. I have a 6.5" midbass in the door (Massive Audio from the late 90's i had laying around).

Current crossover settings varied between two approaches.

First was using steep slopes and T/A based on two different situations:
1. driver seat only
2. both seats
All crossover slopes are 30dB/oct. I get phasing issues when using different crossover slopes, mostly because of the inherent phase shift with crossover slopes. I've found that if slopes are different, driver phase is important to consider. I like everything in-phase, so consistent slopes help me with that. Crossover points are 56Hz - 180Hz for midbass, 200Hz - 4kHz for mid, 4kHz and up for the tweeters. My sound stage is too narrow with this, too much is centered.

The second approach is a new one - no T/A, 12dB/oct slopes all around. This is where the kick mid shines - the sound stage is much wider without T/A, but too close to me. The mono rear fill xover and T/A comes into play heavily for pushing the sound stage away from me. I will slowly work in some T/A, but probably just the door speakers. The higher crossover points coupled with careful level adjustments are getting me great stage width and height.

Rear fill has been very instrumental in developing the sound stage depth. Luckily, the H701 gives me instant access to level, T/A, phase, and xover - because all of this is tuning by ear (with the help of a recording engineer as co-pilot).

Scott did recommend a two-part epoxy for the floor. I am not against that method. I'm also looking at viscoelastic damping compounds (green glue) and cement board or another high-mass, water resistant product. i'm exciting the floor at 125Hz - i have several approaches to solving this. If I do, i may try the 4" in the side again and use the floor 6.5" as midbass again.
One solution is to increase mass of the floor to lower the resonance frequency. another solution is to introduce transmission loss between the cabin and floor. a third is to reduce excitement in the first place.

I want to increase transmission loss anyway, so a decoupled MLV is planned for the floor. To lower resonance frequency, i could throw 3 layers of BXT II on the floor, but will that really drop it from 125Hz to below 50Hz? Added mass may be the key, but how best to adhere the mass - and ideally, absorb some of the vibration. I'm thinking Green Glue may be a key component - in two places. 1. between the speaker baffle and the vehicle to reduce structure borne excitation. 2. between the added mass on the floor and the floor to absorb the structure borne vibration while increasing transmission loss.

Lastly, I did some testing with 12Hz tones by setting up measurement mics in the cabin and trunk. i measured some interesting data - such as more prominent 2nd and 3rd harmonic distortion in the trunk than in the cabin - by like 20dB difference. More concerning was that with windows up, i could hear the speakers in the car audibly moving as a method of pressure release. This got me thinking that at higher volumes (and higher SPL), you get break-up from the driver itself, but you also get distortion from the subs pressurizing the cabin and manipulating the drivers. A cracked window wasn't enough to reduce the cone movement, the window had to be 1/2way down, at least before it was inaudible. I've always recognized that rear deck speakers commonly suffered distortion from trunk subs. But i hadn't thought that pressurization of the cabin affects speakers in doors, kicks, etc. to that extent. The 12Hz tone was at 105dB when the cones moved audibly (by audibly, i'm referring to a flapping sound that seemed to be cone excursion related). I'll perform more testing regarding the difference in harmonic distortion (by lowering the rear seat and also reversing the driver orientation - since it's possible that the rear seat (with armrest down) provided some form of aperiodic filtering. I'll also more closely monitor cone movement, as while audible, the cones were not visible at the time.

[keep_hope_alive]

2011

So as a result of some recent "changes" that I will describe later, i've decided to run door midbass until I build the FG door pods. which, due to winter, won't be started until late spring 2012.

but first, I needed to actually seal up the door this time. before i just had some "thinmat" around the speaker that just simply pealed off (apparently roofing material doesn't stick in the cold).

I used Raammat BXT since i had about 50 sq. ft. of note, having used this and BXT II, there is a HUGE advantage to the BXT II. BXT II is better in every way.

today i'll make a new speaker baffle and move on to the next door.

cleaned and ready, i used a mild mix of oxy clean and some nitrile gloves to clean all metal surfaces.
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started with about 8 sq. ft. on the inside of the door cavity
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multiple layers in the middle of the door
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then i moved to the inner skin
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for the large opening i had a few options. option 1 is to make a fiberglass cover, option 2 is to make a sheet metal cover, option 3 is to make due with materials you have on hand. i chose option 3 since it was around midnight.

i used some thin board and made sure to have deadening on both sides. in this case, i ran a piece on the inside that overlapped the metal on each side of the opening, then used gorilla glue to hold the board to the deadening/metal around the opening, then covered with a few layers of deadener.
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i repeated the process
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mostly finished, i did some trimming along the outer edges
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[keep_hope_alive]

so, replacing front stock speakers in your accord... i wrote this as instructional so i can share my process. in all, about 7 hours on the front driver door, not including wiring.

factory comparison with a late 90's Massive Audio CD6 woofer
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some tools required - a jig saw and drill are essential.
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i find that the holes you cut in sub boxes can be reused for door speakers. here we have 3/4" MDF.

start by tracing the factory speaker mount, then superimpose the new speaker basket outline. determine the outer boundaries of the new mount - making sure you leave ample room for at least four bolts. then mark your driver cut-out in the center - i used the factory cardboard that held the driver for shipping as my template.

secure the wood so you can make your cuts
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drill a hole on the inside of the center cut out, and on the outside of any sharp corners
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always cut the center out first so you can easily secure the overall piece of wood
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test fit your driver
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finish cutting out the rest
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drill out your mounting holes (driver and baffle) and use t-nuts or hurricane nuts for driver mounting. MDF doesn't work well with standard wood screws.
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test fit your piece and use tape to help align the mount. mark your mounting holes so you have a clean cut you need to remove deadener BEFORE you drill - as it makes a mess. use brake-cleen or gasoline to remove deadener from the drill bit.

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test fit the piece - if it's good then secure with bolts. in this case, i am using 1-1/2" 8-32 bolts with a nut and washer inside the door. you tighten with a screw driver and socket driver.
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start by working a layer of deadener around the inside seam where the baffle meets the door
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once it is secure, you can deaden over this piece to ensure it is water proof.
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[keep_hope_alive]

and then wire and mount the driver
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lastly, open cell foam around the driver to facilitate a seal against the door panel (i tightened up the gap)
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5[/quote] [quote=keep_hope_alive]passenger side - pretty much the same thing. another ~20 sq. ft. of Raammat BXT.

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[keep_hope_alive]

updated system wiring diagram. I am looking for a diferent set of midbass drivers and a different set of rear fill speakers. i'm not opposed to going back to Oz or finding something different.

1[/quote] [quote=keep_hope_alive]some recent work to experiment with speaker locations and soundstage width.

i have my midbass in the door now so my 6.5" holes in the floor were empty... until now. I made a ring to mount some mids in that location. I recess mounted them so i had both protection and off-axis control
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both mids can be played, and since they are mostly in the same location, the soundstage differences should be based on speaker orientation.
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same for the driver's side
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yea, i still have the carpet over the drivers - this is how it looks after another winter.
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[keep_hope_alive]

decided to take advantage of 55 deg weather late 2011

new full size spare
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CCF the floor
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glad i save these cut outs
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CCF the cutout top and bottom
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secured the tools to the board. either i have a phillips screw driver on hand (tweaker in the console) or i just break the plastic clips
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next i disassembled the floor amp rack since i already had boards sized with t-nuts. worked great
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hot ****, it fits
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[keep_hope_alive]

now do i put the H701 under the amp or do i store the jack under it?
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new ground location - machine screw into tapped hole that is not exposed to the elements underneath
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what prompted my tweeter project was waiting for the resin to dry on these boards.
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these are going to be on each side of the trunk for securing the H701, power, ground, and all wiring. i wanted a wood surface to secure zip tie mounts that wasn't on vehicle metal. 1/2" MDF coated in resin for water proof-ness.

resin on 1/2" MDF in place
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carpet with Super 77
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my goal this time was to have nicer wire management in the trunk. this isn't done yet, i need to neatly secure the wires as they extend behind the amp rack.
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I am basically re-running every wire in the trunk

[keep_hope_alive]

we talk a lot about capacitors. i tell a lot of people not to use them. there are many reasons for this, and my goal is to maximize their investment. i have invested in my electrical system, now i am trying a cap done as correct as possible - by putting it as close to the leads as possible. these 4awg sections were soldered (Weller torch) to spade and ring terminals.
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amp cover stops at the same plane as the fan on the right, but it is cut out from the factory to clear wiring. the cap terminals are behind the amp terminals - no worries about shorts or anything.

did some progress this morning. too bad i have to go into work, otherwise i could finish today.

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you can see black zip ties on the carpeted board above the power wires, i drilled two holes and zip tied the power wire to the bottom of the board. that way i have strain relief for the distribution block inputs.

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i secured wires with zip tie mounts screwed to either the vehicle or wood. everything is secure.

left to do is the ground for the 3300c and redo the remote turn-on wiring. not much.

then i will have power and can redo all gain settings with a scope.

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I had to redo the remote wire
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quickly revised the floor and trimmed around the 3300c. not final but it was enough for a road trip
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[keep_hope_alive]

Two mics are shown - one in passenger seat and one in drivers seat. Mics are at teh headrest.

I noticed some distortion and some harshness that I couldn't tune out. Then i realized that stupid MX (Media eXpander) was turned on. Not shure when or why. So I flattened the EQ and reset the turning. I noticed that I didn't need much EQ - it is mostly flat - maybe 6 bands are adjusted for the mids and tweeters.

All crossovers are set, I tuned without the sub. I do have some sub adjustments left for a better blend.

Soundstage height is great, nice and wide... and it does two seats quite well.


This was after I flattened the EQ - in 1/3rd octave without sub
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This is same as above in 1/24th octave without sub
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This is everything running - 1/3rd octave with sub
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This is the end result after some tuning effort - without sub
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This is the same as above - current tuning in 1/24th octave without sub.
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New battery - Die Hard Platinum P-4 Group 34/78DT

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The 135 Min. Reserve Capacity and Warranty were the selling points. My RedTop was 7 years old and no longer resting at >12V.

Power Ratings:
Amp Hours at 20 Hour Rate: 68
Cold Cranking Amps (CCA at 0 deg.F): 880
Reserve Capacity (RC): 135 min.

It is made by Odyssey and is AGM

some stuff i've been doing:
finally carpeted my stupid trunk lid. i was also trying to watch my kids so i went quickly. i can go back and fix the cuts in a few places. better than it was.
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[keep_hope_alive]

redid some wiring
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was this


now this
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working on a custom radio mount. it will be painted to match and incorporate gauges. this was the first attempt using a sheet of ABS
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cleaned up wiring behind the head unit
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there's a lot going on there
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new sub grills (from Madisound)
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[keep_hope_alive]

also, some tweeter experiments
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I started making another set recently.

I buy solid wooden spheres ($1.50) - like knobs or post tops, at my local Hobby Lobby. i hollow out a cylinder, (using Forstner bits, hole saws, dremel, etc.), drill a hole for threaded rod, and then... i'm not sure where to go next for a nice finish.

tools i use
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i used double-sided foam tape to hold the sphere in the vice without making marks. works well.
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I had to dremel sand the opening a bit larger in order to fit. the Forstner bit was either too small or too large.
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rods screwed in
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wires soldered on tweeters
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going with hammered silver paint (to match my painted interior)
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painted and waiting (pic taken 2 hours ago)
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i haven't decided how best to finish off the mount. there is a gap around the tweeter face due to it's construction. the widest flange is in the middle. so i need something to create a smooth transition. and then the grill - the Vifa doesn't have one. i have one, but it's larger than necessary.

I used some rope caulk to temporarily hold the tweeters in place and also hold the grill on. i want to test before i make these permanant.

i'm also taking a different approach. instead of having the grill flush with the sphere, i have the actual tweeter cone flush and the grill protrudes - should be better, we'll see.