Car Transfer Function Curves

[bladebarrier 10+ year member]

Are car transfer function curves available online from any of the large manufacturers these days, or do you all still calculate them yourselves?

I have a meter somewhere, but it's been a LONG time, and I'd need to borrow a sub to close mic it, and then measure transfer to sort it out before designing my enclosure.

I was hoping that maybe this kind of data is more commonly available now, for common vehicles?

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[galacticmonkey 5,000+ posts]

This sounds like the bullshat on Pete Kulickis forum. Go use big words there.

http://www.hexibase.com

 

[bladebarrier 10+ year member]

This sounds like the bullshat on Pete Kulickis forum. Go use big words there.
http://www.hexibase.com

Eh? I've been into car audio for about 16 years now, and have always designed my own boxes from scratch. It's part of the fun, for me.

I'm not sure what the hostility is about. Transfer function is just how the car effects the frequency gain applied to a speaker when placed inside it.

It's no different than the reason people often put a home audio sub in a corner of the room.

When I designed my boxes in the past, I tried to adjust the setup for my car, instead of say a full size van, which would make it sound a lot different.

The program I'm going to use to design my new one is Base Box 6, which allows you to put that info directly into it and see the response and output curves "in car". In fact every recommended woofer manufacturer tries to use these equations when producing their suggested box sizes and tuning specs. Are you implying that they're pompous and putting us all down when they suggest optimal box sizes and tuning frequencies?

Anyways, I'm just looking for some help on the subject, and not a flame war.

 

[Rashaddd 5,000+ posts]

lol...why the fvck would car manufacturers waste their time figuring that out?

 

[Rich B 5,000+ posts]

lol...why the fvck would car manufacturers waste their time figuring that out?

Because they use that info in designing their own audio systems to match the acoustics of every single model of car they sell?

Just a hunch.

 

[Rashaddd 5,000+ posts]

Because they use that info in designing their own audio systems to match the acoustics of every single model of car they sell?
Just a hunch.

The average person will not notice a difference, and I'm willing to bet they realize this. Maybe they do in more luxury cars, with high end audio systems, but as OP stated, "common" cars likely don't do much more than throw a couple speakers in there where convenient.

Not to mention most cars have almost no bass to speak of, despite the fact that it takes very little to get some decent low end, and having that low end rather than missing part of the musical spectrum instantly makes a sound system sound much better, instead of sounding like a pair of ipod headphones.

then again, i could be wrong...

 

[Rich B 5,000+ posts]

then again, i could be wrong...

No, you're likely right.

I was thinking higher end cars, the kind with Bose (yech!) or Infinity types of systems in them from the factory when I posted before.

Those vehicles would have the transfer functions measured out by the car company so the third party audio system could be designed to the lowest cost needed to reach a certain sound quality.

But you're right, economy cars probably wouldnt be measured.

 

[bladebarrier 10+ year member]

The average person will not notice a difference, and I'm willing to bet they realize this. Maybe they do in more luxury cars, with high end audio systems, but as OP stated, "common" cars likely don't do much more than throw a couple speakers in there where convenient.
Not to mention most cars have almost no bass to speak of, despite the fact that it takes very little to get some decent low end, and having that low end rather than missing part of the musical spectrum instantly makes a sound system sound much better, instead of sounding like a pair of ipod headphones.

then again, i could be wrong...

One example, would be a 92-94 maxima that was owned by a family member (I forget the exact year). It came standard with a Bose package in the SE model, that included a fixed equalizer tailored to the cabin. Free of extra charge, it was designed to adjust the speakers to the interior.

This would be a "common" car, and certainly nothing elite.

Acoustical engineers spend a lot more time measuring spl levels in cars than people might expect. Generally it's to combat road noise.

Materials similar to dynomat aren't uncommon in many cars, in certain locations. The noise level of a car is a common thing to mention in a review in even a magazine like consumer reports, that could care less about the audio quality from the sound system.

I just hoped that maybe that information would be passed along regularly by now to consumers, either by the car manufacturers or by companies that sell speakers designed to be put in cars as aftermarket products.

I can't imagine how much time people have spent adjusting their 1/3 octave crossovers for SQ competitions, that would have loved for a better base line curve to start from instead of flat "0" gain on all those bands.

People take days tweaking out crossovers, and surely they're not all doing it in Mercedes "S" class sedans.

EDIT: This is the kind of stuff I'm looking for http://www.diysubwoofers.org/projects/other/cartf/

 

[tc300 10+ year member]

Acoustical engineers spend a lot more time measuring spl levels in cars than people might expect. Generally it's to combat road noise.

Materials similar to dynomat aren't uncommon in many cars, in certain locations. The noise level of a car is a common thing to mention in a review in even a magazine like consumer reports, that could care less about the audio quality from the sound system.

you took the words right out my mouth!!! //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[Inferno333 10+ year member]

What's with the hostility on this forum? It was just a question/thought.

Calm down folks.