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.

 

[geolemon]

That's good to know - I only have used that foil tape on ducts and damn it sticks. This foil backing on the ccf is... Eh. It's so thin and feels more like plastic.

I changed my mind on a strategy back there at any rate:
I was hoping to avoid mass-loaded vinyl back there just for the weight savings, but... hatchback.

It's shocking how much sound the compressed carpet of the factory hatch panels actually blocks - but I need more. MLV doesn't heat form well... and you can see the curves back there.

So I'm still rubbing my chin. On the "research alternatives" list.


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[BenevolentDictator]

Those look great. I ordered a pair for my rear doors this past week so I'm anxiously awaiting them. You're far ahead of me on everything so I'm curious to hear your impressions of them.

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]

Those look great. I ordered a pair for my rear doors this past week so I'm anxiously awaiting them. You're far ahead of me on everything so I'm curious to hear your impressions of them.

They are monsters - wait until you hold them - and be sure you prep those rear doors well!

I mentioned some unusual circumstances (including that annual Rust Kote spray) that are leading me to the more difficult challenge of "enclosures"...
Normally I'd take the route of sheet metal/self tappers (thin weatherstrip tape in the overlap), damping material and probably MLV... just seal the door cavity up.

With drivers with such low-end potential, it would be a shame to not do that, see all the excursion - and not get the bass. Not that it's not a shame with lesser drivers too [emoji38]

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[pocket5s]

Those anarchy's are decent drivers. more sub than mb though and I have one in a 25hz tapped horn (not in the car lol). They work "OK" in a door style IB setup but really want a small enclosure to perform.

Unfortunately the RF of new is not the RF of old. I'm sure those amps will do just fine in your application and class D amps these days are way ahead of class D amps from the 90's. If you can't find the Helix amp/dsp combo, Arc Audio has a similar setup, with built in PS8 Pro and JL has a line of amps with their built in DSP as well. All three are excellent choices.

I intend to do a similar mock up for my next project as well, and for pretty much the same reasons.

 

[geolemon]

Unfortunately the RF of new is not the RF of old. I'm sure those amps will do just fine in your application and class D amps these days are way ahead of class D amps from the 90's...

I'm 100%with you in some ways.
When I was managing an RF dealer in the '00s, they had just introduced the P1, P2, P3 subs - and had the audacity to bring cutaways to CES. It was an "emperor has no clothes" moment. All flash and money spent on the outside - no visible tech going on inside. This was back when XBL was pushing excursion and reducing distortion, and the JL W7 even affirmated the XBL approach by cross-drilling their pole piece.in the seems spot as the XBL groove for the same effect...
And here's RF I swear using them to vet out buyers who don't know what they are looking at.
I've been pretty actively disenfranchised (if that's a thing) ever since.

But...
They (to my knowledge) have always had some of the industry's top talent in amp engineers, who are still there today. I haven't seem their amp quality fall off. And if you see teardown videos of these, the engineers marks are printed into the PCBs - like design signatures. So - little clues that they still have the same amp engineers.

I also have a little comfort buffer in that the RF amps not only have more rated power headroom as a buffer (100w per channel vs 75w of the Helix), but they significantly under-rate them still.
So I'm speculating that if you normalized them both to 75w per channel via some conservative gain setting on the RF amps, I'd bet they'd be comparable in SQ also.

But I'm equally confident in the Helix, also compact - waiting for a vendor to get back to me. RF I can get locally... Helix I can't.

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[BenevolentDictator]

Yeah I have a journey ahead of me. I was definitely planning to firm all four doors up as best as I can and go from there. I am hoping they are done the justice they deserve so my mids hammer.

They are monsters - wait until you hold them - and be sure you prep those rear doors well!

I mentioned some unusual circumstances (including that annual Rust Kote spray) that are leading me to the more difficult challenge of "enclosures"...
Normally I'd take the route of sheet metal/self tappers (thin weatherstrip tape in the overlap), damping material and probably MLV... just seal the door cavity up.

With drivers with such low-end potential, it would be a shame to not do that, see all the excursion - and not get the bass. Not that it's not a shame with lesser drivers too [emoji38]

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[geolemon]

Minor update:

Took advantage of some Parts Express sales.

Previously had ordered a UMM-6 for the basement PC.
Can't pass that up for $69, and has its own calibration file, individual to this mic.

I got that set up with the calibration file input into REW...
...then realized I didn't have a headphone-to-RCA cable long enough to reach from my PC to the Yamaha tuner I'm using to power my setup for this testing.
So... One of those is headed my way now.

Today, this box of goods showed up - even added an extra hunk of braided sheithing to get me to the $100 free shipping mark.

Six passive filters in this box-
Two 500hz high pass
Two 500hz low pass

I'm hoping I'll be able to run lower points than this, but this was the only prebuilt option and it would cost more time and money to build filters... to what frequency? Would be a total guess, and this will be fine for my playing with image placement.

But for the hell of it, even though they don't sell corresponding low-pass, I picked up two 300hz high pass filters to see if I can extend that low.

In car, I'll have a DSP and infinite flexibility on filters, so these are just to get a reasonable mock-up for experimenting.


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[geolemon]

Couldn't help myself, so I mounted and wired things up before dinner.

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[geolemon]

Some construction progress. Two steps forward, one step back (and I don't mean with my fiancee who surely will have some questions for me on this beauty in our basement [emoji38]...

The good - success building side window frames to give the right angle and hold some plastic at a curve that simulates the curve and angle of car windows.

The bad - I tried to get off cheap with a florescent light panel, which is textured on one side and glassy smooth on the other. I need the smooth side for the inside - to be acoustically reflective. And it's not going to work out because I impulse bought at a Lowes run without thinking it through - and cutting and rotating leaves me with... two right windows. Doh.

So I now have a 24" x 48" polycarbonate panel headed my way. Easy fix.

On to making the dash top a decent acoustical equivalent.

 

[geolemon]

I had some scrap hardboard from adding a wall of whiteboard to my shop, some scraps of plywood...
Should be a good enough acoustical analog for my dashboard.

You can see spaces I left on the sides -
Those holes are there so I can experiment with speaker orientations - some of them are going to be in that corner dash top location. Easy to cover up for alignments that don't use them.

I can't mock up fake A-pillars until my polycarbonate shows up and I install windows again.

I have a ridiculously thick fake fur rug from Ikea right next to me as I type this... That will go under this rig eventually to mock the acoustic absorption of the car carpet. Another thing my fiancee will love...
Bad enough I've stuck this in the rec area of the basement, now I'm going to steal the rug. [emoji38]

Here's my actual dash for comparison.

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