oz audio ported enclosure

Home / the12volt's Install Bay / Car Audio / oz audio ported enclosure (

Topic Closed)

Welcome Guest :)

Members

Next Page > < Prev Topic Next Topic >

flyonwall9

Member - Posts: 5

Joined: December 14, 2009

Location: Alabama, United States

Posted: December 23, 2009 at 10:45 PM / IP Logged

Good day....

I need help with the design of a ported enclosure. I recently purchased a pair of OZ Audio OZ-250L's to complete the last product in my oldschool build. I'll describe what I would like the enclosure to look like. I would like to have the drivers mounted so that the magnets are external firing into the ported enclosure. What I'm in need of is the total volume of the enclosure, port length, and diameter. I listen to mostly rock, jazz, R&B and seldom listen to RAP. I will have a 8,4,tweeter front stage so I would like the enclosure to be tuned pretty low. I don't have or know how to use any of the enclosure design software, so if someone could model me an enclosure that would be great. If it looks like a sealed enclosure is my best bet then I'll have to figure out how to make that change.

THANKS everyone for your help

OZ-250L 10" Low "Q" Subwoofer
Fs=	23.39 Hz	Re=	3.1 Ohms
Qm=	1.748	Le=	0.39 mH
Qe=	0.656	Xmax=	10.0 mm
Qt=	0.477	Pmx=	180 W
Vas=	3.42 Ft< size=-1>3	SPL=	91.59 dB

haemphyst

Platinum - Posts: 5,054

This member has been recognized as an authority in Electrical Theory. Click here for more info.

This member has been recognized as an authority in Mobile Audio and Video. Click here for more info.

Joined: January 19, 2003

Location: Michigan, Bouvet Island

Posted: December 24, 2009 at 5:39 PM / IP Logged

<sniff>Dave wipes a tear from his eye</sniff>

Ah, I loved those old Oz drivers... Back then, I think those were some of the first SQ woofers I had ever heard.

JBLSpeakershop tells me 3.9 cubes, heavily stuffed, with a 4x17 vent will give you an f3 of 19Hz. Is that tuned low enough? ;) A bit ridiculous in the car, but it will be oh, so musical...

Let me know how much space you have to spare, and I'll plug the numbers in that volume. This was an optimum box for the T/S parameters provided...

:::::::EDIT:::::::

OOH! Was thinking on it while I was watching a movie, and I thought why not ISO load those woofers in 2 cubes, with one 4X34 port, and get the same results! MUCH smaller enclosure, same response! You could squeeze the port to 3X22, but you might get chuffy noises.

It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

flyonwall9

Member - Posts: 5

Joined: December 14, 2009

Location: Alabama, United States

Posted: December 24, 2009 at 7:43 PM / IP Logged

WOW, that is a large enclosure for such a small car.

Then again, I don't think that I said it was a 1987 Porsche 911targa.

I may have to get down to brass tax and take measurements then see

what we come up with. As much as I hate to, I may have to end up with

a sealed enclosure..... BLA!

THANKS EVER SO MUCH, for checking into it for me. I'll post again after

the Holidays and we'll give it another go. Merry Christmas and I hope you

have a safe one!

CHeers,

Scott

haemphyst

Platinum - Posts: 5,054

Joined: January 19, 2003

Location: Michigan, Bouvet Island

Posted: December 24, 2009 at 8:00 PM / IP Logged

And to you and yours, as well!

Be sure you read again my edits... I hit the submit button as you were typing I guess...

They don't like sealed boxes... Best case response in a sealed enclosure of 1.3 cubes each, nets an F3 of 41Hz... Blech! Even bumping the volume to a 2.2 cube hardly changes the response at all. FANTASTIC group delay (<9mS across the board) and phase (within 90ᵒ across the board), they would sound awesome, and probably be "kick-you-square-in-the-throat" snappy, but would not be a true "subwoofer", in any respect.

It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

flyonwall9

Member - Posts: 5

Joined: December 14, 2009

Location: Alabama, United States

Posted: December 24, 2009 at 8:16 PM / IP Logged

You know, I do recall not seeing too many people use these in a sealed

enclosure. That does play into my hands, I didn't want one to start with!

The location I have in mind for these is the area where the rear seats

are. Like who on earth is ever going to sit in the back of a 911? lol......

I should also say, that I only have 200-250w max to send to these from

half of a Blade SE8.4. I do have a fall back plan IF the enclosure for these

10's are just too large. That would be a new in the box pair of the 8s I think

model number is OZ-200L. Again, this would be a last ditch effort only.

OZ-200L 8" Low "Q" Subwoofer
Fs=	29.50 Hz	Re=	3.1 Ohms
Qm=	1.252	Le=	0.47 mH
Qe=	0.462	Xmax=	8.0 mm
Qt=	0.338	Pmx=	150 W
Vas=	1.54 Ft< size=-1>3	SPL=	90.66 dB

stevdart

Platinum - Posts: 5,816

This member has made a donation to the12volt.com. Click here for more info.

This member consistently provides reliable information

Joined: January 24, 2004

Location: Pennsylvania, United States

Posted: December 24, 2009 at 8:25 PM / IP Logged

Those drivers are made for a sealed enclosure (35.7 EBP) but still need better than 1 cube for each woofer. Start with a 2 cf sealed box and add as much as you can to that. Each little bit of space you can add will get it closer to a .8 Qtc. Anywhere you can do it from min. 2 cf to 3 cubes.

Edited to add: use the dialog box on this site to type your response. Your copy-and-paste isn't appearing correctly.

And, don't go to smaller drivers, as you have 8's in the front stage. If anything, go to a single 12" , is the way I would approach this.

Oooops, just read haemphyst's last retort. He knows these woofers, I'll bet, and if he doesn't like the response in sealed alignment then he's probably right. Me, I'll betcha I'd like the sound, sealed, in a Porsche.

Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.

haemphyst

Platinum - Posts: 5,054

Joined: January 19, 2003

Location: Michigan, Bouvet Island

Posted: December 24, 2009 at 9:09 PM / IP Logged

Seriously... The 10's, ISO-loaded, 2 cubes, with the 3X22 vent. That 250 watts you have would be perfect! Deep and VERY musical, I think you'd be happy, still be able to get the (small enough to be easily removable) box in the car, and keep one rear seat!! :P

Are you thinking the output might not be enough? You won't notice the difference between one 10" and two 10" drivers, with an acoustic output difference of less than 3dB.

A 1.3 cube sealed is a Q of .707 (F3 @ 40.3) for those drivers. Max transient response, with minimum group delay, and best output across the band. Best compromise between extension and power handling. 2.2 cubes drops the Q to .621 (F3 @ 40.2), heading towards thinner sound, you might like the sound of a sealed enclosure. For a max-flat Q of .5 (F3 @ 42.3) they want a MONSTER 7.5 cubic foot enclosure! (Out of the question, certainly, but maximum extension, with lowest mechanical power handling.) A nice "whumpy", or "sloppy" Q of 1.1 gets you the best power handling, with the highest F3 of them all - at 53Hz - but only .3 cubes per side with heavy stuffing. (That'd be about 5 to 6 ounces of Dacron pillow stuffing per enclosure.)

All of those sealed alignments, as you can see, drop your F3 between 40 and 55Hz... Woofer territory for sure, NOT subwoofer. A territory that should already be addressed by your 8's in the doors. I'd seriously consider the 10" ISO loaded vent.

:::::::EDIT:::::::

TL, BABY!!! Not worried about space? Check it! :) I know I love mine!

It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

flyonwall9

Member - Posts: 5

Joined: December 14, 2009

Location: Alabama, United States

Posted: December 24, 2009 at 9:35 PM / IP Logged

Quite honestly I could get very creative with an ISO set up.

How about a vented/ported isobaric (planar loaded) type

enclosure?

I do very much agree, I do want the subs to be tuned as

low as possible. The first model you did tuned at 19hz,

well, that is right up my alley! As you said my 8s in the

doors will be crossed over as low as I can get them on

my ES crossover. I really don't know what that is off the

top of my head. BUT, and this may be an issue; the low

xover point of those 8s will also be the high crossover

point of the subs. Its how the XES-X1 works.

haemphyst,

I gotta say, this is the most and best info I have been given on

my system to date! It really is like a Christmas to me! Now I will

admit some of the nomenclature is beyond my understanding.

But, hey, thats ok, you type it and I'll figure it out.... :)

THANKS MUCH!

haemphyst

Platinum - Posts: 5,054

Joined: January 19, 2003

Location: Michigan, Bouvet Island

Posted: December 25, 2009 at 1:45 AM / IP Logged

flyonwall9 wrote:

Quite honestly I could get very creative with an ISO set up. How about a vented/ported isobaric (planar loaded) type enclosure?

Huh? Do you mean both drivers visible on one mounting surface, one magnet in, and the other magnet out? That's not isobarik... Isobarik mounting means one woofer will be buried, and only the cone of one of the drivers will be exciting the air in the listening environment. Vented, though... Even with iso loading, those drivers simply won't go deep in a sealed setup.

flyonwall9 wrote:

I do very much agree, I do want the subs to be tuned as low as possible. The first model you did tuned at 19hz, well, that is right up my alley! As you said my 8s in the doors will be crossed over as low as I can get them on my ES crossover. I really don't know what that is off the top of my head. BUT, and this may be an issue; the low xover point of those 8s will also be the high crossover point of the subs. Its how the XES-X1 works.

Ahhh... A man after my own heart! LOL I don't care WHERE a subwoofer is to be installed, I like to try to model for deepest (theoretical, anyway) response. The TL that I linked to you is the sub in my 2001 Civic, and it ended up with an Fs of 25Hz, and an F3 of 19Hz. People thought I was nuts... A little...

As far as the crossover settings, nearly ALL analog domain crossovers (I can't come up with even on that had independent sub-low-pass and midbass-high-pass settings, they are all automatically ganged. My suggestion would be this: Decide on the system design you like. Install it. Tweak the crossover point until you're happy. That's about all there is to the process. "As low as the crossover goes" is not necessarily the answer, either. That might be too low for your doors. Play with it, and somewhere in the range, you'll hear a magical "blending", where the sub seems to be coming from the footwells. That is what I look for when tuning my high-end systems.

flyonwall9 wrote:

haemphyst, I gotta say, this is the most and best info I have been given on my system to date! It really is like a Christmas to me! Now I will admit some of the nomenclature is beyond my understanding. But, hey, thats ok, you type it and I'll figure it out.... :)

It's what I do... :P If I sometimes get a little phraseology happy, (I've been accused of teaching how to make a clock when asked the time!) please ask what I mean... I'll happily explain. I am glad I can get you excited about this little project! I like the idea of it, myself!

flyonwall9 wrote:

THANKS MUCH!

Merry Christmas!

It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

flyonwall9

Member - Posts: 5

Joined: December 14, 2009

Location: Alabama, United States

Posted: December 25, 2009 at 2:30 AM / IP Logged

OK, I have no idea how to do the quotes thing you did to get my

statements above your reply. Not really worried about it now. BUT

I looked at one of my owners manuals for my ES system to see

what my crossover points are for the sub/midbass. It says in

4way mode the lowest sub filter I can do is 78hz with a 70db/oct

slope. So, it will play up to 78 hit a wall then my 8s come in.

"(I can't come up with even on that had independent sub-low-pass and midbass-high-pass settings, they are all automatically ganged."

The equipment I use and have had it for nearly 15 years is the OLD

Sony Mobile ES system. This was the original digital preamp eq /

crossover with time alignment that came out in the late 80s. Then

Pioneer's ODR came along. Which didn't have a crossover near as

good as the Sony. I honestly didn't believe the crossover slope was

as deep as advertised until I saw it for myself with an RTA. It does

have sub/midbass/mid/high in 4 way mode which I've only ever

used. I have all the time correction and eq I'll ever need and have

had no problems blending any of my other subs in with my front

stage. Heck the thing is so powerful once I put a mid/tweet mounted

in a little pod on the floor under your knees and made them sound

as if they were mounted on the pass side mirror. Its really cool doodie.

I think I have figured out a way to get as much volume as possible and

it will be a run of the mill iso loaded box like what your suggesting. I

just have to get out and do some measuring. I'll get all that figured up

and post it up as soon as I can. I hope to really start hammerin on the

install after all the Christmas fun is over.

Next Page >

Printable version

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot delete your posts in this forum
You cannot edit your posts in this forum
You cannot create polls in this forum
You cannot vote in polls in this forum

Search the12volt.com

Follow the12volt.com

Disclaimer: *All information on this site ( the12volt.com ) is provided "as is" without any warranty of any kind, either expressed or implied, including but not limited to fitness for a particular use. Any user assumes the entire risk as to the accuracy and use of this information. Please verify all wire colors and diagrams before applying any information.