News

Mathlete needed

Discussion in 'Technical Q&A' started by SoftwareDrone, May 12, 2020.

  1. SoftwareDrone

    SoftwareDrone F1 Veteran
    Rossa Subscribed Owner

    Jan 19, 2004
    6,279
    San Jose, California
    Full Name:
    Mike
    I have a right triangle with lengths 33" and 54.2". I need to know the larger of the two inner angles.
    I have another right triangle with lengths 43.8" and 8". I need to know the larger of the two inner angles.
    What does this have to do with Ferrari?
    The attached two drawings will show that if the tweeter in a 360 or a 430 were tilted at these two angles, the stereo imaging for the tweeters would be greatly improved. The way it is set up from the factory, the tweeters simply fire into each other. This information would be in this forum and available to anyone who could benefit from it.
    Thanks guys.
    Image Unavailable, Please Login Image Unavailable, Please Login
     
  2. ylshih

    ylshih Global Moderator
    Global Moderator Owner Advising Moderator Honorary

    Mar 21, 2004
    15,336
    Northern CA
    Full Name:
    Yin
    #1 = 52.5 degrees (arccos 33/54.2)

    #2 = 79.5 degrees (arctan 43/8)
     
    hessank and tomc like this.
  3. SoftwareDrone

    SoftwareDrone F1 Veteran
    Rossa Subscribed Owner

    Jan 19, 2004
    6,279
    San Jose, California
    Full Name:
    Mike
    Yin, you are AWESOME!!! :)
    Thank you my friend.
     
  4. SoftwareDrone

    SoftwareDrone F1 Veteran
    Rossa Subscribed Owner

    Jan 19, 2004
    6,279
    San Jose, California
    Full Name:
    Mike
    So, for a sanity check:
    The tweeter needs to be tilted back toward the rear of the car (90 - 52.5) = 37.5 degrees.
    Also, the tweeter needs to be pointed up (90 - 79.5) = 10.5 degrees.
    Does this sound right?
     
  5. ylshih

    ylshih Global Moderator
    Global Moderator Owner Advising Moderator Honorary

    Mar 21, 2004
    15,336
    Northern CA
    Full Name:
    Yin
    Given a starting orientation of 90 degree side pointing with 0 degree tilt, that sounds right.
     
  6. SoftwareDrone

    SoftwareDrone F1 Veteran
    Rossa Subscribed Owner

    Jan 19, 2004
    6,279
    San Jose, California
    Full Name:
    Mike
    Man I am glad you explicitly stated that assumption. I went out and checked again, and, although the angle of the tweeter along the length of the car is 90, the tweeter is not actually firing right into the other tweeter. It is firing downward. I need to figure out what that angle is and add to the 10.5 degrees.
     
  7. SoftwareDrone

    SoftwareDrone F1 Veteran
    Rossa Subscribed Owner

    Jan 19, 2004
    6,279
    San Jose, California
    Full Name:
    Mike
    The tweeter fires so far downward that by the time it gets to the listeners' ear, the sound is only 6 inches from the floor!!
    So whatever angle #3 is, I need to add that to 10.5 degrees, and we'll have the perfect listening angle to go along with the horizontal angle.

    Image Unavailable, Please Login
     
  8. SoftwareDrone

    SoftwareDrone F1 Veteran
    Rossa Subscribed Owner

    Jan 19, 2004
    6,279
    San Jose, California
    Full Name:
    Mike
    #8 SoftwareDrone, May 12, 2020
    Last edited: May 12, 2020
    I found a trig right angle calculator online and it looks like angle 3 is 32.12 degrees. This sounds right.

    So, the tweeter needs to be tilted back toward the rear of the car (90 - 52.5) = 37.5 degrees.
    Also, the tweeter needs to be pointed up (32.12 + 10.5) = 42.62 degrees.

    At these angles, the music will hit the occupant on the other side of the car right square in the face at ear level.
     
  9. ago car nut

    ago car nut F1 Rookie
    Silver Subscribed

    Aug 29, 2008
    4,928
    Madison Ohio
    Full Name:
    David A.
    That's great! But who listens to the radio in a Ferrari that makes glorious engine music?
     
  10. SoftwareDrone

    SoftwareDrone F1 Veteran
    Rossa Subscribed Owner

    Jan 19, 2004
    6,279
    San Jose, California
    Full Name:
    Mike
    ditpixs likes this.
  11. Skidkid

    Skidkid F1 Veteran
    Rossa Subscribed Owner

    Aug 25, 2005
    6,119
    Campbell, CA
    Full Name:
    John Zornes
  12. SoftwareDrone

    SoftwareDrone F1 Veteran
    Rossa Subscribed Owner

    Jan 19, 2004
    6,279
    San Jose, California
    Full Name:
    Mike
    I found one that would give me one angle, but the link to yours is much better! Thanks John. :)
     
  13. Skidkid

    Skidkid F1 Veteran
    Rossa Subscribed Owner

    Aug 25, 2005
    6,119
    Campbell, CA
    Full Name:
    John Zornes
    And they told you you would never use that high school trig class. ;)
     
  14. BillyD

    BillyD Formula 3
    Silver Subscribed

    Feb 28, 2004
    1,598
    Pacific Northwest
    Full Name:
    Bill
    As long as there are math wizards here, may I ask a question. I’m doing my front suspension and will be setting the toe-in soon. The manual calls for 2-3mm toe-in, that’s with the metric 390 wheels which I think are close enough to 15inches for this.
    So what would the toe-in be for 18inch rims?
    Thanks
    Ps I looked at the links, still too complicated for my foggy mind.
     
  15. greg328

    greg328 F1 Rookie

    Nov 17, 2003
    4,120
    Austin, TX USA
    Full Name:
    Greg
    Can you just get some tiltable tweeters and then sit in each seat and look at the tweeter and and angle it toward you? And don’t worry so much about the math part?


    Sent from my iPhone using FerrariChat.com mobile app
     
    Hocakes and BOKE like this.
  16. SoftwareDrone

    SoftwareDrone F1 Veteran
    Rossa Subscribed Owner

    Jan 19, 2004
    6,279
    San Jose, California
    Full Name:
    Mike
    So the 458/488 pod is mounted at a better angle. Actually, both angles are better. If a tweeter were attached, it would only need to be angled up 21 degrees and angled back 32.8 degrees.
     
  17. SoftwareDrone

    SoftwareDrone F1 Veteran
    Rossa Subscribed Owner

    Jan 19, 2004
    6,279
    San Jose, California
    Full Name:
    Mike
    If I am going to post information for use in the public domain, I had better make sure it is correct.
    While calculating the 458/488 angles, I realized I had made a mistake with the up angle on the 360/430. I took the difference between the distance from the floor of the car to the OEM tweeter sound destination from the distance from the ground to the occupant. It should have been the distance between the floor of the car of the OEM tweeter sound and the distance from the floor of the car to the occupant. So this statement:
    Also, the tweeter needs to be pointed up (32.12 + 10.5) = 42.62 degrees.
    Needs to be:
    Also, the tweeter needs to be pointed up (23.2 + 10.5) = 33.7 degrees.
     
    Qavion likes this.
  18. Tegethoff

    Tegethoff Rookie
    Silver Subscribed

    Jul 19, 2014
    31
    Los Feliz
    Full Name:
    Adam
    Wheel diameter has an effect on the way toe functionally affects the chassis and tire flex but not in a 18-15=3 kind of way.

    Toe is usually set at the circumference of the tire, if your tire is the exact same diameter, it would be the same. Wheel diameter doesn't specifically factor in actual measurement of toe.

    I would guess that your 18's have a different profile in the contact patch and possibly not the same width, you may have to make some adjustment to the spec if you are searching for the exact right setup for YOUR car with a different tire profile and construction.
     
    BillyD likes this.

Share This Page