David Clarke aviation headsets in a car

Discussion in 'Wireless & RF Design' started by laro, Dec 5, 2010.

  1. laro

    Thread Starter New Member

    Dec 5, 2010
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    Hi people,
    I own a 1978 land rover series III. I love the car but it has one major drawback... the noise! When driving along on the motorway its near impossible to talk to other passengers or listen to the radio.
    My idea is the following - buy 4 used david clarke aviation style headsets from ebay and link them up to each other allowing everyone in the car to communicate with each other whilst blocking out the car noise and possibly even hooking the system up to the radio/mobile phone.
    I'm quite a DIY'er but don't have much experience with electronics/radio stuff. So would like to tap into this knowledge base and ask your help/input/ideas on how to make such a system.
    thanks
    Paul
     
  2. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
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    You may want to look into yanking the intercom and audio system out of a crashed motorcycle such as a Gold Wing. All of the features you are looking for are there, and not much tinkering. The downside is they are designed for only two people.

    A 4 way intercom is quite a bit more complicated than a 2 way intercom, especially when it needs to cut off the music.

    If you haven't had any experience with reading schematics or electronic assembly, it would be best to find a commercial unit that performs close to what you'd like, then slightly modify it to be exactly what you want.
     
  3. kinarfi

    New Member

    Nov 26, 2010
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    Mix all the audios and send to every head set, it would be monaural though, but work, I did that with my Lynx head phones in my off road buggy. But all I did was feed my stereo into the aviation radio port.
    kinarfi
     
  4. Kermit2

    AAC Fanatic!

    Feb 5, 2010
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    The intercom we build for hush houses uses those exact headsets. The circuits that drive them are quite simple and use discrete components. updating them to opamps would improve them considerably. The circuit boards are purchased from David and Clarke as well.

    They are a 'PTT' system. Push to talk.

    http://www.davidclark.com/PDFfiles/3100Brochure.pdf

    Designed to fit in water tight electrical conduit type boxes and be covered with standard electrical outlet cover plate. Run along the walls in standard pvc or aluminum conduit. should do fine in a vehicle. Schems too.
     
  5. Rbeckett

    Member

    Sep 3, 2010
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    Word of warning. Headsets are illegal. You cannot block the outside noise to insure that you hear emergency vehicles approaching. Get caught with em on in Fla and the fine is 386.00 first offense. Suspension of privilidges second plus fune, and jail for the third. Check you location closely before you do that. Sorry
    Bob
     
  6. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
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    Are earbuds allowed? I use my stereo earbuds w/mic for hands free on my Droid all the time. When not on the phone, I listen to music or a book.

    Do they have a "no cell phone while driving" law there, or is it ok if you use a hands free phone?
     
  7. retched

    AAC Fanatic!

    Dec 5, 2009
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    Earbuds are a no-no also.

    Apparently hands free allow outside noise in. (Obviously, there is a mic on it) And they only use 1 ear.


    Your best bet is sound dampening undercarriage treatment.

    There are adhesive backed foam/tar sheets you can use, or thick spray types.

    Do you have carpet in the rover?

    If yes, yank it and get sound deadening padding for underneath the carpet.

    Undercarriage spray works REAL well. If you have room, deaden the firewall.

    The firewall and above the exhause are very helpful.

    A car is a metal can. A metal guitar body. It resonates and amplifies sound...quite well.

    Firewall, and carpet or underspray will quiet things up.

    Headliner keeps ground noise from bouncing off the roof and back at you.

    This should all cost less than a few of those headsets.
     
  8. laro

    Thread Starter New Member

    Dec 5, 2010
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    Some good tips there people. I'm sure its possible to buy David Clark electrics, but they ask aviation product prices - go check out their site.
    The legal issue is certainly something to consider, will have to look into that.
    My best bet now seems the goldwing style system and then maybe just settle for just two headsets. What's the deal with a ptt system? Seems a pain to first press a button before talking.
    The thing on soundproofing is that a series III land rover is hopeless. It's a utility/military vehicle. It leaks, its cold, its even windy inside ;)
    Thanks for the tips - keep them coming!
     
  9. Rbeckett

    Member

    Sep 3, 2010
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    Laro, I appologize for leaving the thread with no real help. Undercoating and a product called dumb-dumb will help measurably. The Dumb-dumb is a tar llike substance with a protective cover on one side and a very strong adhesive on the back that will conform to the contours of the chassis and deaden the noise considerably. You can get this at most auto A.C parts suppliers. also a look at all of the hangers and brackets are in order. Especially the exhaust and drive train mounts to insure there is no metal to metal connections without a rubber isolator between. Older vehicles deteriorate in this area and create a lot of moise in those two systems. But, please do not use headphones, for your safety and the safety of the emergency crews around you. Hope this helps, And I appologize for the seemingly negative reply and assure you that I am not pulling your leg on the sound deadener material.
    Bob.
     
  10. Rbeckett

    Member

    Sep 3, 2010
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    Technically any item in your ear will get you a ticket, but earbuds are difficult to detect. Best advice I can give from a safety standpoint is to not use anything. I used to drive energency vehicles and you would be amazed at how many drivers do not use there mirrors and cannot hear a 130 Db siren over there music. Sometimes the seconds saved mean a life or a limb.
    Bob
     
  11. aklosak

    New Member

    Nov 16, 2011
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    Paul
    I also have a 1978 Land Rover Series III 88 with 2.25 Diesel
    at 80km/h (50mph) noise level is at 90dB(A), which is about 10dB more than in other similar cars (about 2x more loud). It is very annoying to drive on the highway. At idle it generates about 70dB(A).

    So we did exactly the same what you said, and bought 2 David Clark stereo headsets and a smaller one for our daughter (I have 3 seats in row). we also got a Pilot USA intercom (4 place PA400-st). now we all can talk, listen to music or radio. Quality of DC headset if perfect and you can use them without being tired for a long journey.

    As my LR is a military version in green matt colour, DC headset colour is almost identical, so it looks like a standard equipment :)

    regarding safety issue, I can hear all the warning signals, klaksons, etc. But we do not have such a law here in poland, at least I hope we don't :)

    regarding noise levels in my LR it was obvious that noise was generated mainly by rattling noise from gearbox and engine. I am doing a engine overhaul now, and can see that piston rings were completely loose. When I finish this and also gearbox rebuild I am pretty sure noise levels should go down. So before you start damping noise with some rubber mats try to check the engine/gearbox.

    cheers
    andy
     
  12. radiohead

    Active Member

    May 28, 2009
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