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Designing/Planning a proper Car Audio System. (6.5" or 7" midbass and tweeter combo)

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  • Designing/Planning a proper Car Audio System. (6.5" or 7" midbass and tweeter combo)

    Hi All,

    It's been about 20 years since I've posted here on the PE TT. I was an avid speaker builder and audiophile while in grad school (and quite active on the TT forum and live speaker building events), but I had to step away from it all in lieu of my growing family and career.

    I recently bought a 1st gen Toyota Sequoia, and decided it was time to invest in a proper system... so i took it upon myself to build it out (in the great chip shortage of 2021 no less). My components are:
    1. Two headrest monitors and an overhead monitor... you know, for the kids.
    2. Two SAS Bazooka 8" DVC @ 4 ohms per coil. I have them wired in series/parallel creating a 4 ohm load. (These have sat in a box unused for 20+ they're basically NOS and were the impetus for this whole build. Since I have them, why not use them?)
    3. JVC KW-1000z floating head unit. (5 volt output with built in DSP. I honestly wanted a more humble head unit, but it's the chip shortage--so it was this or a Boss unit. And if I'm dropping this much $ on a head unit, I would have preferred the Kenwood XR version... but there's a global chip shortage, so you get what's available.)
    4. Kenwood 802-5 amplifier. (Wasn't planned--but if you're dropping some coin on the floating head unit you didn't want, why not get the amp as well? Gain all the way down---this isn't for SPL but for sound quality. And I've got two bazooka tubes, right? They deserve the dignity of getting some use.)

    5. So while talking to my "advisor" from a major online car audio vendor, I settled on the Focal Auditor series... the RSE-165 components for the front and the RCX-165 coax for the rear. It's hard picking speakers without hearing them first, but the name and my advisor saying that it was a "silk aluminum" tweeter drove the choice. In hind sight, I should have gone Morel.

    After a while, I just found these speakers hard to live with. So I waited for them to break-in. And it helped...a little. The tweeters were just... at first, bright and clear. But once your ear locks in on them, they're easily distorted/compressed. Almost like they're mylar. So I go to the Focal website, and sure enough... Mylar. Really pissed me off. So I called the company that rhymes with 'muchfield', and informed them of their error. They've now corrected their error, but haven't really made any real effort to make it right. Add up all that I've spent in the past few months... pretty bold and shocking move for a company that 100% mislead consumers. But I digress.

    I could probably fight with them and return them...but then what? I used their online audition feature w/ my sennheiser HD600, and really found nothing in that price range that was decent (sans the Audio Frog, which creates some installation headaches.). Then it hits me... I remember back in the 2000s, I realized that car audio components are over-priced and under-quality.

    So I've been lurking at PE, seeing what's better. And since I've got an active DSP headunit, I can use it as an active XO for the fronts... (And I'm assuming I can use the built-in headunit amp to run the rears full-range?). So assuming this is the case--what can I fit in an 06 Sequoia. It's not a bad platform, as it's big... and that space affords a number of options...

    Just to let you know...
    (1) I'm an electrostatic guy. I have a set of Acoustat 2+2 electrostatics in my house, and another set in my research lab.
    (2) Don't really care about SPL; I'm more of an SQ guy.
    (3) I like dipolar...obviously not a thing in car audio, but I prefer the big open soundstage when possible.
    (4) Perhaps due to my electrostats, I have an affinity for ribbon or planar tweeters. Silk if i have to go dome.

    Here's what I'm thinking...
    Woofer Choices.
    RS180P-4 7".
    RS180-4 7". (This one seems like it's got real potential. A little concerned about a paper cone, but not overly so.)

    Tweeters: (Too many great choices!)
    RST28F-4 1-1/8" Reference Series Fabric Dome. (Can you imagine XO-ing this at 1.6khz at 24db/oct LR? If I can make this fit in a fabricated sail panel, this may be a winner.)
    PT2C-8 Planar Tweeter. Call me stupid, but if I can fit a 6 in planar tweeter in a custom fabricated sail panel, I'm really interested...
    DC28F-8 1-1/8" Silk Dome Tweeter. (If the RST28F doesn't work out, I've got a great smaller option)
    nd25fw-4 1" soft dome. (I built with a similar Vifa a bit back 20 years ago. Great to XO at 2.2khz)
    ND28F-6 1-1/8" Neodymium Dome Tweeter. (Even smaller faceplate... great option for XO at 2.2khz)
    XT25SC40-04. (Another awesome option; XO as low as 1.6khz @ 24db/oct)

    So in essence, I want to DIY this... simply out of spite. The original online vender seems to be "OK" with deceptive advertising (at full price no less), and the quality for the price is crap. We will do better.

    The collective brilliance of this board is incredible. And I'm sure that others have figured all this out. Any thoughts, comments, or opinions are welcome... It seems to me that:
    RS180-4 7" wooer + RST28F-4 tweeter would be ideal (if I can custom fabricate well enough to make a sail panel for the tweeter). Perhaps XO as low as 1.6khz at 24db/oct?
    ...and if I can't make the oversized tweeter work...
    RS180-4 7" woofer + XT25SC40-04 tweeter. Perhaps XO at 2.2khz at 24db/oct.

    And high-pass the woofers at 80 hz; subs at 80hz 24db/oct.


  • #2
    How / where are you mounting these drivers in the car?
    Isn't it about time we started answering rhetorical questions?

    Paul Carmody's DIY Audio Projects
    Twitter: @undefinition1


    • #3
      It was a 3-way 'premium' jbl system. I replaced it all. The 7" midbass are in the lower/front door. The tweeter is in the "sail panel" in the front door (directly on the other side of the side-view mirrors).

      But I'm open to anything. Easiest to just use a 7" driver for a near drop-in-replacement for the factory location. The tweeter... that's another issue. The sail panel is big enough to hold a 1" tweeter (w/o a large faceplate). And you can buy a set for $50 bucks or so to play with. I also have 3D printing available on campus, which may be another cool option.

      here's a pic of the door:

      A crappy pic of the door plus the sail panel:


      • #4
        The XT25SC40/90 is only good to 2.6kHz, and does not have great off axis response due to ring radiation. Not a great car tweeter unless it is aimed at you.

        My thought? Use a 2" wide range driver and xover low to get the blending between them easier. Around 500Hz-1kHz would be good. I really like the TB W2-803SM.

        "Wolf, you shall now be known as "King of the Zip ties." -Pete00t
        "Wolf and speakers equivalent to Picasso and 'Blue'" -dantheman
        "He is a true ambassador for this forum and speaker DIY in general." -Ed Froste
        "We're all in this together, so keep your stick on the ice!" - Red Green aka Steve Smith

        *InDIYana event website*

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