Three years to get around to my own install.

[geolemon]

OK - so I promised that we'd move the 3D printing stuff into it's own thread. I'll do that once I have my V.2 done... like I said I got a lot done, but I'm still learning.
Maybe once I do that I can even have some of these posts physically moved into that new thread? I'll ask Al or pull in a mod to see if that can be done. To keep this one more on track with the "build" aspect...

Although again, I do want this to be a "daily driver" build in my Civic hatchback that I love in part because of the hatch and cargo capacity, so one goal is to have the ability to remove the subwoofer and still safely operate the car (read: no dangling wires, much less wire strands touching and shorting my sub amp).

I thought I'd take THAT to the next level because I am trying to also build in some kick-ass midbass into this car, and that may even take the form of actual sealed enclosures in all four doors - so I could have an actual DSP preset for operating with no subwoofer - turning off the sub channel and allowing the midbass drivers to play all the way down, possibly.

And also, because I'm also playing around... passive radiators, different sub tech, dual-chamber tri-tuned, swapping subs in all the above - I want the ability to be able to quickly and easily swap out those sub boxes.

Point being - this will end up as a part of this build, to facilitate that flexibility.
...also, accordingly I'm planning on installing it backwards - with the terminal cup on my trunk wall, and my sub boxes having leads that magnetically connect to that cup. But that's just me, I think that shouldn't alter the design.

[BigAl205]

You could start your own thread, or feel free to jump in here https://www.caraudiojunkies.com/show...ighlight=prusa

[geolemon]

So an update on something related to sound quality.
Some of my build here has been in the works for between 10 or 20 years:

I think I mentioned here or elsewhere - back in my years in the car audio industry, I was fortunate to attend 10 CES shows in Las Vegas. And for many of those years, after learning about it, I made sure to spend at least a half day outside the main LVCC complex, at the high-end audio section... there's really no better way to develop a 'tuned ear'. These are entire hotel rooms that have been emptied out and vendors come into each room to hook up anywhere from tens of thousands to hundreds of thousands of dollars worth of the most exotic, high-end audio gear you have ever caught glimpses of in magazines. Vendors can prep the room for acoustics, set up furniture for their targeted listening position, use their choice of exotic turntable, pre-amp, solid silver interconnects, flagship speakers... whatever produces a demo that says "Look! We know how to make things sound perfect. Buy our products!" So, just walking from room to room, listening to vendor after vendor, exotic rig after exotic rig - you definitely develop a tuned ear.

And what that means is you not only can understand what's "good", but also the boundaries of what's possible - and since you can hear so many systems, you can learn what's possible tonally with one rig, and then another vendor you hear one that's more impressive with stage width but not as tonally good.. then another vendor you hear one that's just got shocking presence and range between absolute silence and the actual instrumentation such that you can actually hear the silence... etc, etc, etc.

It's also interesting to hear half-million dollar setups that are impressive... but maybe not "half million" impressive.
Then you walk into a room and hear a side-system that was basically thrown together to show a different application, that doesn't cost much, yet nearly blows your mind.

Such was the case with the Bolzano Villetri room that I heard in 2006. Their 'Roundstream' technology really isn't proprietary per se, there have been different takes on omnidirectional loudspeakers going back decades. But when you are walking around the high-end section, listening to demo after demo, from sofas carefully placed far away from rear walls, listening to speakers ideally positioned away from front walls - then you spot this system they set up on the side in a bedroom, with a sofa right against a wall, and the speakers nearly against the other wall - that catches your eye.
So you ask for a demo, and when the imaging is not only great, but maybe the best you've ever heard... that makes an impression.
And the impression? It's one of the only times in my life - certainly the pinnacle - where my brain was unable to reconcile the difference between what my ears were hearing (a broad, deep soundstage, with individual musicians, far wider and deeper than the speaker positioning) and my eyes were seeing (sofa-width-spaced speakers that were a foot in front of an untreated bedroom wall). The imaging was that convincing.

And the cost? $3700 for the two smaller speakers they used for that demo - not cheap for Best Buy shoppers maybe, but one of the "OMG" cheapest at the high-end section.
That stuck with me - that implies there's no million-dollar patent-backed proprietary magic going on - just regular speakers:

Basically, two identical vented cabinets for the midrange drivers, one firing up from below, one firing down from above. The pod in the middle holds two tweeters - also one firing up, one firing down.

So of course, that's impossible to do what BV did here, in a car.
But for years and years, I've been holding this as my imaging benchmark - something I strive to replicate in a car.
With all the hi-fi snobs scoffing at car audio, with all the reflective glass and offset seating positions - who wouldn't want to prove them wrong?

And might there be lessons we could take from this BV experience, that could at least be applied, even if their actual implementation couldn't be directly used?

14 years later... ...gotta be a way...

[geolemon]

So I think I may have found a way - let the experimentation ensue!

If you do some searching for existing omnidirectional loudspeaksers, you get exotic stuff like this:

(if interested in how that works - that mbl actually is an array with a tweeter in the middle, small mids above and below, and the big pods are midbass - they all have a voice-coil assembly above and below, which pull and squeeze vertically, flexing the panels in between, causing them to emit sound in a 360 degree radiation pattern. The cabinet next to it is traditional cone based subwoofers for bass.)

But you also get some simple implementations like this:

The idea here is that an up-firing speaker plays into a reflector, which helps radiate that sound into the horizontal listening plane that more naturally replicates a 360 degree radiation pattern that sound really takes.Aha! ...of course, we can't really implement this in a car either, because we have A-pillars and glass and a windshield - and we'd be launching that sound right into it.

So back to ...?

[geolemon]

So, as it turns out, there used to be a manufacturer of some omnidirectional speakers that were even designed to mount on a wall. They are discontinued now, but you can see two in this picture - mounted upside-down and against both the wall and ceiling (as the manufacturer recommended, for installation above ear level) - and you'll note these are small:


Here's a close-up of this speaker, and it's pretty interesting:


I've of course been researching them, and I even just purchased a used set off Ebay to listen for myself.
Reviewers (professional and otherwise) seem impressed by the imaging and staging just like I was with the Balzano Villetri, but this package is much more compact.
Again, these were expensive for Best Buy level customers, but not even half the price of the Balzano Villetri's that I fell in love with. And used - pretty cheap.

Here's what I'm observing of the design:

• It's small - one model used a 2.5" midrange and a .75" tweeter
• The midrange is on a small angle, to add a small amount of directional energy and eliminate the issue of the reflection from a wall mount application.
• The midrange fires into a 360 degree reflector, which is shifted back from center for a designed 30% direct / 70% reflected strategy.
• The tweeter is mounted in the mid's reflector pod, with it's own reflector - in this case a vertical angle.
• The magnetically attached grille is pretty slick - can't avoid the dome shaped result, but hides the UFO shapes.

So I'll play with the set that I purchased, when they show up.

I might even be able to play with the midrange and reflector and steal those dimensions directly. And that might be another good reason to actually make that 3D printer purchase.
One reason I decided to buy my own Mirages, even used, is because they were regarded as an industry leader (apparently the general omnidirectional category isn't large, since they are now defunct), so I believe I can use these for reference on the type of plastic they used as well.

I also wouldn't be opposed to doing the tweeter in this same design - we'll have to see if it's too bright, being close to the glass, or perhaps if that can also be mitigated with a larger diameter reflector if so...
...or maybe we just end up with the tweeter in a traditionally aimed sail panel pod.

Hoping this is a "Eureka!" ending to a long path. Can't wait to see!

[Ge0]

So I think I may have found a way - let the experimentation ensue!

If you do some searching for existing omnidirectional loudspeaksers, you get exotic stuff like this:

(if interested in how that works - that mbl actually is an array with a tweeter in the middle, small mids above and below, and the big pods are midbass - they all have a voice-coil assembly above and below, which pull and squeeze vertically, flexing the panels in between, causing them to emit sound in a 360 degree radiation pattern. The cabinet next to it is traditional cone based subwoofers for bass.)

I authored a senior year college paper on a design similar to this back in 1994. But, instead of exciting the upper and lower pod elements with voice coils they used natural gas ignitions to excite the elements. Bizarre yes. Effective, dunno. As a poor college student I didn't have $90K to buy one and evaluate.

Still. I think this might not be so practical for a car

Ge0

[Ge0]

So, as it turns out, there used to be a manufacturer of some omnidirectional speakers that were even designed to mount on a wall. They are discontinued now, but you can see two in this picture - mounted upside-down and against both the wall and ceiling (as the manufacturer recommended, for installation above ear level) - and you'll note these are small:


Here's a close-up of this speaker, and it's pretty interesting:


I've of course been researching them, and I even just purchased a used set off Ebay to listen for myself.
Reviewers (professional and otherwise) seem impressed by the imaging and staging just like I was with the Balzano Villetri, but this package is much more compact.
Again, these were expensive for Best Buy level customers, but not even half the price of the Balzano Villetri's that I fell in love with. And used - pretty cheap.

Here's what I'm observing of the design:

• It's small - one model used a 2.5" midrange and a .75" tweeter
• The midrange is on a small angle, to add a small amount of directional energy and eliminate the issue of the reflection from a wall mount application.
• The midrange fires into a 360 degree reflector, which is shifted back from center for a designed 30% direct / 70% reflected strategy.
• The tweeter is mounted in the mid's reflector pod, with it's own reflector - in this case a vertical angle.
• The magnetically attached grille is pretty slick - can't avoid the dome shaped result, but hides the UFO shapes.

So I'll play with the set that I purchased, when they show up.

I might even be able to play with the midrange and reflector and steal those dimensions directly. And that might be another good reason to actually make that 3D printer purchase.
One reason I decided to buy my own Mirages, even used, is because they were regarded as an industry leader (apparently the general omnidirectional category isn't large, since they are now defunct), so I believe I can use these for reference on the type of plastic they used as well.

I also wouldn't be opposed to doing the tweeter in this same design - we'll have to see if it's too bright, being close to the glass, or perhaps if that can also be mitigated with a larger diameter reflector if so...
...or maybe we just end up with the tweeter in a traditionally aimed sail panel pod.

Hoping this is a "Eureka!" ending to a long path. Can't wait to see!

I see custom a-pillars on your horizon...

Ge0

[Justin Zazzi]

Have you see the acoustic lens that Bang and Olufsen put in higher-end cars?

[geolemon]

I authored a senior year college paper on a design similar to this back in 1994. But, instead of exciting the upper and lower pod elements with voice coils they used natural gas ignitions to excite the elements. Bizarre yes. Effective, dunno. As a poor college student I didn't have $90K to buy one and evaluate.

Still. I think this might not be so practical for a car

Ge0

For sure not practical for a car... but using some crazy suck-squeeze-bang-blow cycle to drive a speaker sounds directly analogous to electric cars vs. gas cars. I can't see how you wouldn't want to make a prototype!
Sounds like an idea almost as extreme as the concept I proposed to have two scaled-down (read: hobby sized and legal) railguns firing a panel back and forth at each other, in a discussion on Xmax that went off the rails (no pun intended)

...I definitely can see not wanting to buy a $90K mbl, but that's just me. I'd pull apart a speaker and glue my own carbon fiber (or cereal box) panels to the voice coil and fire it up and proof-of-concept that baby!
And I honestly cant' think of a better potential thing to go with a plasma tweeter - Google that if you haven't before. Sound from a flame - definitely also not car-safe.

I see custom a-pillars on your horizon...

Ge0

Well - I'm actually wanting to integrate it into the dash, since
I'm hoping that I can pop off this "defroster garnish panel" as the Honda manuals call it - that's the very top of the dash extending across the windshield (sorry my wide-angle lens makes it look a little weird here):

Note this is the same panel/location that ErinH's installer managed to fit small enclosures with a bit of air duct re-routing:


He had pretty low-Q speakers that require an enclosure, I'm not settled on a specific mid yet. I'll keep the options open until I can get that panel off and do some testing.
Mine wouldn't be nearly as stealthy, I love how unbelievably factory and clean ErinH's look - but probably wouldn't look too odd.
I think I'd keep those Mirage removable grilles, and probably do black plastic - or maybe even use those very structures, painted black

Have you see the acoustic lens that Bang and Olufsen put in higher-end cars?

So this is a big help - thanks! And it's interesting in that it looks both similar and different than the Mirage pods...

The Mirage claim is their 70% reflected / 30% direct goal, between the offset reflector and the 15 degree angle, is about actual acoustics and trying to mimic actual sound reflections in natural environments - which - fine, cool.
However, I also think it lends itself to how they can have a speaker that people have had wall-mounted (and not by a rogue attempt - it comes with wall mounts) and been stunned that it acoustically makes the wall disappear.
But that's a wall, and a wall isn't a corner with an angled windshield hovering overhead. So as I do my listening to these Mirage's in their as-is state, I'm going to try to replicate that one way or another.

What your B&O pics show me, I believe, are more traditional tweeters with more or less waveguides to direct the sound energy forward, is that correct?
So what they are trying to achieve is avoiding windshield reflections - I think that's twofold in their case - they have that scoop around the tweeter diaphram to prevent sound from moving rearward, and then the UFO overhead is probably to block sound energy from traveling vertically at least to the angle where it clears the windshield overhead?

What's interesting is - do you see that old Civic that's in front of my daily Civic, in my dashboard pic above? That was the first new car I ever bought, in 1995... and I still own it.
One of the things I did over the years was fabricate these, out of clear plexiglas:

I was trying to get factory locations to "work", and at least with the tweeters I succeeded (those mids on the other hand... as you can see by the non-stock grilles, I can't tell you how many things I have tried and failed, to work around the midbass acoustic null that this car is definitely plagued with, using those locations... but that's for a whole different thread).
In my case, I was intentionally directing the sound toward the windshield, and blocking only the near-side tweeter from having a direct path. Meaning, if you sit in either seat and look at the tweeters- if you look at the closest one, you can only see it through the glass. If you look at the far side, it's hardly blocked at all by the shield. The idea was to equalize pathlengths... the far-side-to-ear being pretty similar to the near-side-to-windshield-to-ear distance. It actually worked out... so I can confirm, tweeters can be blocked and guided like B&O is doing.

And that's actually exciting to see, because like I mentioned above - I was hoping that IF the tweeters were too bright with their tiny shields and the windshield right overhead (probably predictable, right?), that maybe I can simply make bigger overhead shields...
I think B&O is saying "Yes, yes you can!"

I hope this is one of those "the stars are aligning" projects...
...but I still haven't even heard these Mirage's yet.
Can't wait for them to show up.

[mikeyt]

Your tweeter's got a COVID shield...how thoughtful...lol