ultimax 18 box modeling help needed.

[Jwhite]

I have been on a quest for satisfying bass for long enough. Chasing after the boxed offerings with not much reward has been exciting and bad for my wallet but most
importantly has left me still wanting more bass. I would like to build this to function as furniture and subwoofer. I have some outside dimensions I would like to work with but dont have the know how to design a proper box. W/d/h 57 5/8 x18 x20.I dont know what to do can you help?

[Chris Roemer]

Re: ultimax 18 box modeling help needed.

Build you box. Use a 6"id PVC pipe that's 24" long for your port. Feed 1000w w/NO boost (be sure to wire the voice coils in series). Be happy.

[RoryB@daytonaudio.com]

Re: ultimax 18 box modeling help needed.

Here are my thoughts on some good enclosure sizes for the Ultimax 18.

Possible enclosure alignments:

Car Audio - 3-4 Cubic Feet Sealed, anechoic F3 30/27 Hz

HT/Music - 4-6 Cubic Feet Sealed, anechoic F3 27/26 Hz, Qtc 0.9/0.8

Home Theater - 8 Cubic Feet Vented, 20 Hz tune, anechoic F3 = 18 Hz

Infrasonics - 14 cubic feet vented, 15 Hz tune, anechoic F3 = 14 Hz

Infinite baffle use - OK

The parameters of the UM18-22 make it usable in a variety of enclosure configurations - it's not restricted, for instance, to sealed enclosures. If necessary, you can squeeze one into a 6-cubic-foot vented box tuned around 20 Hz. Variety is the spice of life.

[Jwhite]

Re: ultimax 18 box modeling help needed.

Thank you for the responses. I am curious about the 14 cubic foot enclosure it is a bit larger than my measurements but I can make room for it. I have plans to use this sub for music and movies would this enclosure work for both? I know I can use it for both but will it sound good for both? Would a slot port work or should I use round ports?

[Jwhite]

Re: ultimax 18 box modeling help needed.

I came up with 60x21x23 for box dimensions which after sub displacement is about 13.9 cubic feet. I came up with 3" wide by 19.5" tall 44" long vent for about 15hertz the displacement for the vent is about .66cubic feet. I dont know how to come up with those graphs you guys use or even how to read most of them but I do understand that is an important part of this process. Can some one help me out in that aspect of this design? I want to be sure this will perform in both movies and music.

[RoryB@daytonaudio.com]

Re: ultimax 18 box modeling help needed.

Hello Jwhite,

You'll want to use a box simulation program to verify your calculations. A good free one that is easy to learn is WinISD.

Are you sure you need the largest recommended box? Would the 8-cubic-foot vented alignment be enough? No need to build an enormous box capable of subsonics if you aren't sure that you need it. The smaller box will play just a bit louder.

[Jwhite]

Re: ultimax 18 box modeling help needed.

I was just trying to fill a particular foot print in my tv room. I guess I will have to think about this a bit more. Thank you for your help thus far.

[Chris Roemer]

Re: ultimax 18 box modeling help needed.

WinISD is FREE at www.linearteam.org

[Jwhite]

Re: ultimax 18 box modeling help needed.

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[Jwhite]

Re: ultimax 18 box modeling help needed.

I am looking for an amp for this that I can also repurpose if need be. I have a pioneer elite vsx-30 for a receiver I hope to be able to one day power all of my speakers through seperate amplifiers. Maybe even build one more subwoofer to match this one. Any suggestions?

[Wolf]

Re: ultimax 18 box modeling help needed.

I am looking for an amp for this that I can also repurpose if need be. I have a pioneer elite vsx-30 for a receiver I hope to be able to one day power all of my speakers through seperate amplifiers. Maybe even build one more subwoofer to match this one. Any suggestions?

A Crown XLS1000 gives 550W x 2 @ 2 ohms, the 1500 is 775W x 2 @ 2 ohms. If you want headroom, get the 1500, but the 1000 is likely enough. I use the 1500 as a mains amp for my front L/R. You will also get more output running it 2 ohms per channel than 4 ohms as a series load. Same power in, different sensitivity out.

Later,
Wolf

[JRT]

Re: ultimax 18 box modeling help needed.

I have been on a quest for satisfying bass for long enough. Chasing after the boxed offerings with not much reward has been exciting and bad for my wallet but most
importantly has left me still wanting more bass. I would like to build this to function as furniture and subwoofer. I have some outside dimensions I would like to work with but dont have the know how to design a proper box. W/d/h 57 5/8 x18 x20.I dont know what to do can you help?

Jeremy, describe the room, length, width, ceiling height, construction/materials, open to the house or closed off, sealed up tight with A/C or windows open to the outdoors.

In-room response and anechoic (free from boundary reflections) are two different things, and the loudspeaker enclosure models use anechoic, because room applications can vary significantly, so are kept separate in the modeling tools. A smaller, tighter, more rigidly constructed room will provide boundary reinforcement at lower frequencies. A larger free breathing space doesn't provide that, and would need flatter anechoic response for flatter in room response.

So to get an idea of how to shape response for your application, we need to better understand your application, need to know more about the room.

[Jwhite]

Re: ultimax 18 box modeling help needed.

JRT my room is technically two rooms. My kitchen and family room are joined and they open up to my dinning room and living room and also a small halway leading to the laundry room and garage. The opening to the dinning room is standard doorway sized my ceilings are a mix of 9' and vaulted ceiling it is about 50/50. The space measures 20'x25' I hope this is understandable and what you wantedto know. Thank you for your help with this. I plan to purchase 4 sheets of 3/4 birch and some other lumber for this box in the next few days. I have a x4000 and some others parts on the way so its time to build.

I forgot to mention it is a wood frame house with tile floors. Windows are usually closed and central air running. I do have area ruggs and plans for some type of wall treatment.

[Jwhite]

Re: ultimax 18 box modeling help needed.

I picked up a few sheets of 3/4 birch today and all of the other small parts I thought I may need for the enclosure. How does room size effect box design? Do I need a larger box for a larger room or is this something that effects the tuning of the enclosure?

[Sounder]

Re: ultimax 18 box modeling help needed.

I picked up a few sheets of 3/4 birch today and all of the other small parts I thought I may need for the enclosure. How does room size effect box design? Do I need a larger box for a larger room or is this something that effects the tuning of the enclosure?

IMHO I think your asking way too many elementery questions to be designing your own cab. You should consider a flatpack, or get a set of very detailed plans, like Bill's Simplexx 18. He just added a sealed version for the Ultimax 18.

http://www.billfitzmaurice.com/Simplexx.html