Car 2way crossover design

                                                                                            by  Russell Storey

" Peerless Vifa & Swan Combo " 

Car cabin acoustics
The car cabin interior is probably one of the most challenging and variable  acoustic environments to  model and design a good  speaker system. Apart from the interior shape size and seating position and several other factors listed below we have engine and road noise that  reduce the over all dynamic range of the car speaker system .The best way to  hear how dynamic and detailed a car speaker system is  can be  when the vehicle  is stationary with the engine turned off and located in a quite car park or garage. Also you will notice as you  gradually increase the speed of the vehicle then you  increase the noise induced into the cabin from the tyres engine and car body wind turbulence and one usually starts  increasing the master volume level to compensate for the masking effect of the external noise until you suddenly  reach the   amplifier and speaker( dynamic) limits. That is the car sound  system ( distortion + noise )  begins to irritate your ears at a certain (volume level+ car speed) so  usually you  either reduce the volume level  and or reduce the speed and volume level to make the sound less distorted and more coherent .
Car crossover design process
Aim : T
o design a Stones custom Car sound system based on say a  peerless -Vifa logic (tweeter module) and a pair of Hi-Vi (swan speaker) 6.5 woofer with a 3 full range woofers for the rear parcel shelf.  We ask the client what they require from  their car system  and  how much dollars they intend to spend  so this then enables us to make  educated  recommendations on the equipment  and component  options  to ensure  the best sound from the car sound system  .
During your custom Car Crossover   design Stones take into account  the speaker size ,T/S  parameters , frequency response and the effect the car has on these ,Also driver location , baffle shape , size ,type of driver mount,  vertical mount ( ceiling firing) , side mounted ( side firing )  , dash tweeter ( 45,0 deg firing) , door mounted , dash and window shape , cabin volume  & shape dependent on vehicle type ( sedan , station wagon, sports , 4wd ), rear location , distance from listener  to front and rear speakers ,speaker panel type, raised enclosure  thickness rear subwoofer volume and  panel damping compounds .

What does this all mean
The Car speaker crossover design works as a  closed loop system  in conjunction with all of the above parameters to determine the car cabin  sound quality when the vehicle is  stationary or at speed .

Car Audio Amplifier type, Subwoofer , Bass Mid & tweeter
We also  need to know the Car System amplifier type ,number of channels ,power rating ,does it have Individual  ch level matching controls, Subwoofer type , ch level matching control ,size ,location and lp filter frequency  used on sub, sub phase sw control,  so we can recommend the optimum  integration of the subwoofer sound to match  to the rears and  front speakers to achieve not  just good but excellent  fast dynamic detailed sound over the whole bandwidth

To be continued>>>>>>>>>..........


            CAR                 HIGH END          SPEAKER SYSTEM


Car :BMW 
Control unit :Pioneer P9
Control processor :Pioneer DEQ9 32 channel digital crossover  with fiber optical link from P9
Power Amplifier Front 3 way Speakers:   Celestra VA210 x 2        hand made in Italy 100khz bandwidth

Power Amplifier Twin rear Subwoofers:   Celestra  VA210 x 2          '''    ''     ''      ''    ''   ''     ''     '''    '
Speakers Drivers 
Tweeter               x2             1''  Scan Speak D2904-700000  revelator-ring radiator
Midrange             x2          2.5''  Scan Speak 12M4631G00     revelator-slit cone
Bass Midrange   x2          6.5''
  Scan Speak 18W8531G00     revelator-slit cone
Subwoofer          x2           10''  Peerless XLS 830514             Xtra Long stroke

           Nathans BMW

SCAN Speak 6.6''
Scan Speak 18W8531G00 mounted in passenger door with metal cone protector
SCAN Speak 1''
Scan Speak D2904-700000 Revelator Tweeter 
SCAN Speak 2.5''
Scan Speak 18W8531G00  Midrange  mounted in custom enclosure on door post

PEERLESS  10''  XLS 830514   twin Subwoofers mounted in custom enclosure in the boot
Celestra  VA210 x 2   Amplifiers for the twin subwoofers
 Celestra  VA210 x 2   Amplifiers for the front stereo 3 way 6channels fed by Pioneer 32 ch digital  processor and control unit