Bought the Civic Hatch lease out, so rebooting the install thread

[geolemon]

So lots of background and planning and experimenting in the old thread...

Covid hit, my lease turn in was delayed - finally I just wrote a check and mailed it in. I love this car, and the lease purchase price was cheap. Win/win.
Since it was a lease and I wasn't 100% that I was going to keep it, I really never did anything to it audio-wise previously, as that would have jeopardized the lease.

It's a 2017 Civic Sport hatchback, and I've been inspired to some degree by ErinH's Civic Sport hatchback, although I'm not directly snagging any of those ideas. The pictures have opened up the possibility of dash speakers, in a different way - possibly being the key word.

I've also had a lot of other things pop up - sided my house before the weather turned, been working from home - so I haven't been here for the past couple months. We'll see how things go from here out, going into the winter. I'm in Buffalo, NY so the weather is already in the 50's frequently, and we get into the 30's and even 20's with lots of snow. Winter progress will probably be slow, but on the other hand - owning the car and not having to commute daily opens up more possibilities for tear-apart than usual.

I also purchased a 3D printer this year, opening up some unique installation opportunities to explore over the winter.

The plan: (partly worked out from that original thread)

• I want to use my factory door locations for four midbass drivers, in an attempt to kill the usual midbass null. I'm hoping to build enclosures behind them - but I haven't had the doors apart yet.
• I want to add two small wideband speakers in pods to custom locations way back in the hatch - they'll be exclusively differential rear fill from a DSP processor, and will additionally be delayed. This is just to simulate live environments, so I may have a switch to enable/disable it.
• I've discovered a cavern of space behind my rear wheel. Going to make a space for one of my single 12's in there, and possibly something a little convertible for a couple different modes of use for different types of subs.
• The front stage is something to be tackled - I have two experimental ideas at this point.
  I'll have some pics later when appropriate, but I'm nearly complete on a basement "lab", with a windshield/dash/A-pillars/windows assembled for listening purposes, in a way to facilitate auditioning experimental setups. I want to prove them plausible or bad, before tearing my car apart.
• DSP - TBD. There's a few ways I can go.
• Channels - already looking like 11 channels.
• Amplifiers - I'm an audio geek. I like technology. I like progress and progression. And I don't have much space if I want to retain my spare tire and install my amps beneath the hatch floor. So as a middle age guy, I remember when class D amps came out in the 90's and really helped kill the high-end audio industry. So it's intriguing me massively to see higher-end class-D amps serving full-range capacity. I used to sell Rockford Fosgate, and one area I still respect them for is amplifiers. It's something to see their high-end Power amplifiers having a pretty impressively compact and powerful design that really could fit the bill. Considering them, but also considering other compact options. With lots of "dirty, old" class D amps still on (and even popular on) the market, I'm going to have to shop carefully. But I'm ready to start that.

[geolemon]

So I had an opportunity to start pulling my hatch apart, to explore what's behind and underneath those panels.

Because the Sport model has a center exhaust, the floor under the spare is higher, so the hatch floor is suspended higher up. See those foam blocks? Plenty of wasted space:


After I pulled everything out, I couldn't believe how much space there is in this rear quarter area (12W7 for size reference):



And I also can't believe how flat the surfaces are here - I thought I was going to be stuck fiberglassing this whole thing, but I was able to use birch ply to at least build the rear, bottom, and side walls, to get a structure going:

I'll still need to be doing some 'glassing for the side and baffle, to integrate it cleanly - but I want this hatch to be functional, so I want to fire the sub up as much as I can (so cargo doesn't risk striking the cone).
Likely, about like this:


Also, I won't be sanding sanding sanding for some painted finish - this one will be carpeted for as practical, use-able, and stealthy appearance as I can.

[geolemon]

This past weekend, I raided my storage unit to pull out a big roll of Second Skin Extreme that I still had that I'd been sitting on for probably 10 years.
I didn't trust the adhesive so much, so I used lots of heat and a special roller I have with a skateboard wheel on it.

...I burned out the "high" mode on that cheap heat gun doing this, and had to buy another heat gun. Bought a cheap Wagner, and fortunately all the accessories the cheap one came with fit it nicely. Even fits in the case- I'm a bit of a tool organization nut so that was important.

After doing enough damping material to kill the panel vibrations, I tackled adding closed-cell foam (10mm, adhesive, foil backed) to the hatch area. There's still a few spots around the actual hatch door that I'm leaving for now, and two spots on the top of each strut tower that I'll just be handling later when I have those panels off as well. I wanted to tackle this area primarily since I can get started on a lower panel that will be the basis for an amp rack, and a new upper trunk floor that will be more functional than the flimsy foam-lifted carpeted panelboard that came stock.

The blue masking tape line you keep seeing is where a plastic factory panel ends, one that holds the trunk light and privacy screen. I want to retain that, so keeping the sub box below that line.

I'm also going to tape all the seams on the CCF layer. The adhesive seemed great, but that will help with the integrity and even the sound barrier.

I haven't decided if I'm going to just use the uber-sticky and conformant PVC tape (I have a bunch left from installing Tyvek and foam board before siding my house), or the thicker and more rigid aluminum tape like you see on aluminum duct work.

I'm also going to need to figure out some forced induction flow for housing tiny amplifiers in a small enclosed space, so I'm going to need to track down some silent fans. My goal there isn't to impart a cooling force, just to gently circulate air - pulling cool air in on one side, and pushing warm air out on the other.
I may also try to add some sort of electronic thermal switch in here also in parallel to the remote turn on lead - which also will power a relay, and in turn the amp turn ons and the fans - doing that would keep these fans and the amps powered on, if the temperature is too high - until sufficiently cooled.

[Fernpatch]

for good quality fans that move lots of air without noise I would recommend looking at a brand called Noctua. I started using them in my computer builds and have been nothing short of majorly impressed with them.

[Ge0]

for good quality fans that move lots of air without noise I would recommend looking at a brand called Noctua. I started using them in my computer builds and have been nothing short of majorly impressed with them.

I'll second that. Just get the new black ones vs. the beige / tan puke colored ones

Ge0

[geolemon]

Perfect, thanks.

Not yet sure where I'm going to make the air entry/exit points from, but I do want to do a push/pull. I probably won't be able to get away with using fewer than 4 fans, since there's a circular spare tire in the middle and I'm going to also need to manage the air circulation around both sides of the tire, potentially. Shouldn't be too tough, because I also need to support the floor - so those supports will do dual-duty walls that guide air.

ALL these things I need to fit into that sub-floor space circling the spare tire - the portion the sub box isn't occupying already. There's really not too much space.

I am considering a plan B to ditch the spare tire and replace it with an OEM-style fix-a-flat/inflator kit, but as mentioned in that other thread - I am intrigued by new class D full-range amps [like the RF Power] that promise high-end-sound, and are small enough to enable 11 channels of amplification in a space this small. There's a risk there, that I buy them and am disappointed that they really haven't achieved "class-A/B-like-sound" yet, and due to space constraints - simply can't replace them with equivalent A/B amps. The progress-pushing geek in me is curious enough to find out, though. Can't learn by staying in the dark.
...Plan B does exist - if my front vs. rear door speaker pathlengths aren't too different, I could parallel those midbass and also eliminate my differential rear-fill (locations TBD), and get down to 6 channels plus sub...
But that would be less ideal from a tuning standpoint than plan A...
Also, the differential rear-fill is also something that's surprisingly difficult to answer "Can ____ DSP do that?", in narrowing down the DSP list.

That being said - I've been surprised to see the 8 channel Helix amp with built-in DSP is small enough to fit in here - so that is definitely going on the list of contenders. Unfortunately I don't have any Helix dealers within hundreds of miles - nowhere in the northeast apparently. Worst case, likely could find an anonymous dealer/member hook-up, I would imagine. That does add a different sort of risk, however... buying unauthorized/unsupported.

So - still lots of considerations. But I'll look into those fans... at least fans are cheap and swappable.

[geolemon]

Minor update...

I mentioned that I was going to spend the winter experimenting.

I wanted to make an easily-tweakable listening lab in the comfort of my basement man cave, to play with all winter (it's cold here, we get snow).

So I scored a [cracked] Honda Accord windshield from a friend who had hers replaced. She sweet talked him into leaving the old one. It's got a bunch of cracks now since he didn't remove it so gently, but for my needs here it should be perfect.

I mounted it in a frame, with a fake dashboard, and set the angle exactly to the angle of my Civic dashboard on the passenger side. In the car, the center rises slightly higher and the gauge cluster slightly higher still, so I'll eventually mock up something for that.
I'll also need to mock up something non-vertical for side window reflections and A pillars and a sail panel.



Why am I doing this?

Above-dash installs are tough to get right.
I am intending to do something entirely unconventional, also. So I want to mock it up, test it out. Make sure the very idea isn't a bust, before I cut and fabricate and find out things didn't work out like I hoped.

This will let me mock up different speaker alignments in a close enough approximation of "my car interior" to hear how they will affect the imaging.

By spring, when it's warm enough for some fun driveway installing again, hopefully I'll have a finalized alignment that works.

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[geolemon]

A little speaker porn strip tease...

First off, "four" seems like the right quantity to order these in. I received one full box, packed inside another box, nicely padded with Styrofoam chunks.


Carrying these in from my porch - my first impression is "damn these are heavy!" It's impressive, but I'm glad they'll be low in my door because I like the handling of my light, fun car.


You can see why - these are XBL^2 midbass drivers. The top plate needs to be thick, similar to an underhung driver, even - the only difference being there's a circumferencial deep groove circling the inside, changing the magnetic field... allowing BL to stay constant across huge excursion when paired with a voice coil of correct length.

They took all interesting approach - machining two half-top-plates and stacking them (one inverted), to keep costs down. Smart.


Going to set two up in little sealed test cabinets and park those on the floor roughly where my door speakers would be, for now.


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[geolemon]

I mounted two of the Exodus Anarchy in test cabinets and set them on the floor, and you can see I have two Pro Tech Time Lense tweeters sitting on the cross brace that will become the front edge of my dash.
They are just sitting there.

The tweeters are filtered off my old JL crossovers - you saw them screwed to the sides, above.

Was fun just giving an initial listen, simulating sitting offset like in a car.

As far as initial impressions, I'm pretty impressed with the tonality and detail of the Exodus. I really didn't push them hard and they aren't broken in, and I was listening totally on-axis - but I'm feeling relieved already.
I hate buying sight-unseen (ear-unheard?).

I need to add or build another Xover to filter the midbass and the future-widebands I built this to experiment with. For now I think I can guess at a xover frequency... For my experimenting, that should be fine.


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[Theslaking]

You mentioned foil duct tape. It doesn't stick well to anything other than clean metal. And ever after rolling it can still be pelled off. I used it in my truck when I insulated the floor of my work truck. It was ok but not great. Not bad enough to retape but I won't use it again in a car. If you want to go the foil route use some Pella foil backed butyl window tape.