Please Help With Box Volume

[bruhthakuga]

Friends,

How do I select a box volume for a 6.5 inch driver that I do not know the T/S parameters for?

I know that with a shop full of expensive equipment and some know how that I can estrapolate the T/S but currently have niether.

Are there places that one could take a driver to get the T/S and if so about how much will that cost?

I have Alpine SPR-17S componet speakers in my car which come with no driver info.

Please Help.

[JustinG]

> Friends,

> How do I select a box volume for a 6.5 inch
> driver that I do not know the T/S parameters
> for?

> I know that with a shop full of expensive
> equipment and some know how that I can
> estrapolate the T/S but currently have
> niether.

> Are there places that one could take a
> driver to get the T/S and if so about how
> much will that cost?

> I have Alpine SPR-17S componet speakers in
> my car which come with no driver info.

> Please Help.

I would try to contact Alpine to get an approximation of the T/S parameters. If you are near someone here that has the equipment they might be willing to take measurements for you.

[bruhthakuga]

OH! I forgot to say that I tried that, the guy on the phone told me that they don't have T/S parameters, Go figure

Now if someone have a phone number or email address that will get me paste the mormal channels I may be able to get results?

[denton]

Car speakers like this are designed for infinite baffle ("free air") use. If your plan is to create enclosures for use in the car you may be in for a disappointment; the specs will likely lead to a large sealed box. (Good luck)

[bruhthakuga]

You may be right but where are these specs that may lead to a large sealed box? I want to see if it is viable, if I can bring the lows out some more.

[Chris Roemer]

> You may be right but where are these specs
> that may lead to a large sealed box? I want
> to see if it is viable, if I can bring the
> lows out some more.

Try a 1 cf sealed box (which means about 0.8 cf, sealed and STUFFED) for an F3 of maybe 80 Hz.
Try a 1.7 cf lined box with a 2"d x 1.5" port. Maybe this will reach 40 Hz.

[aarond]

I have experimented w/ enclosures for mid/high drivers designed for car use. It is always readily apparent that they are designed for IB use (as far as the lows are concerned).

How do you have these mounted currently?

I have a woofer tester and would be gald to test them for you if you cover shipping both ways. Send one or both and I will test whatever but please keep in mind this is only good for t/s type data not response plots (I don't have a setup to do that yet).

It really isn't that big of a deal but I am guessing that it is more effort than practical to find the results that I and others are predicting. Only one way to know for sure though.

Email me if interested, or look at the WT2 price and see if it is something you think you might be better off getting now. It is far from the price of "a shop full of expensive equipment".

Aaron D

> Friends,

> How do I select a box volume for a 6.5 inch
> driver that I do not know the T/S parameters
> for?

> I know that with a shop full of expensive
> equipment and some know how that I can
> estrapolate the T/S but currently have
> niether.

> Are there places that one could take a
> driver to get the T/S and if so about how
> much will that cost?

> I have Alpine SPR-17S componet speakers in
> my car which come with no driver info.

> Please Help.

[bruhthakuga]

I have two in the front door, However, for now they stick out a bit as the original where smaller and I like my window to roll all the way down. I have two in the back on the Mcpherson strut wells which by the way originally had four or five inch drivers in small enclosures.

They actuall sound great but I was thinking that if I could enrich the low portion, which is stated by Alpine as 65Hz I could get a little overlap with the sub woofer which would be better.

The brite side is that I don't have to make enclosures which would've been a female dog as I cannot use square boxes.

IB it is, thanx friends.

[bobblickle]

Provided Link: DIY Audio Car Audio Forum


> I have two in the front door, However, for
> now they stick out a bit as the original
> where smaller and I like my window to roll
> all the way down. I have two in the back on
> the Mcpherson strut wells which by the way
> originally had four or five inch drivers in
> small enclosures.

> They actuall sound great but I was thinking
> that if I could enrich the low portion,
> which is stated by Alpine as 65Hz I could
> get a little overlap with the sub woofer
> which would be better.

> The brite side is that I don't have to make
> enclosures which would've been a female dog
> as I cannot use square boxes.

> IB it is, thanx friends.

Just make sure you're getting a good positive mount and a solid seal where they are "sticking out"

If you did elect to make enclosures, an aperiodic vent might be another alternative that is more forgiving/tune-able. Never tried that but it might be viable.

On the one hand I can't disagree that typical car audio drivers are "designed" for infinite baffle however I would take issue with most of them being any good used that way. Personally I would rather have them in an enclosure that is maybe a little too high in Q but that I know I can safely drive them without constantly running out of stroke. Consider also high passing them if you haven't. That idea sounds counter-intuitive but clearly they will never do what your sub can so why make them bear the burden. Say you roll them off at 100, at least all the way to 100 you can actually drive them.

You might also check in at the car audio forum on diyaudio... as someone may have your T/S.

bb