HUGE box Build

[SeanDub 10+ year member]

I’m in the process of building a box for a DD9917 (and there is a build thread on here that will be updated this weekend). But consider this situation for me for a second:

So you just built a box for a sub and after installing the system it doesn't sound as great as it should. So based on how it sounds and thinking the problem is the box...

How do you know if the box is too big or too small for a sub?

How do you know if there is too much or too little port area for a sub?

What is port noise and what does it sound like?

I was hoping those of you who build a lot of boxes and have heard a lot of setups can answer these for me. People say they can hear what's wrong with the box from hearing the setup, and I was wondering what to listen for.

I haven't finished my box yet, but I want to know what to look for after my install to know if I need a better design and another box. Thanks guys

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[rpfuror 10+ year member]

Wel this is not easily described, you just kinda know by experience.

Port noise will be probably the most noticable.

Assuming the tuning of your box is correct:

At higher volumes within you tuning pass band (crossover point to the tuning point) you will litteraly hear a noise an octive higher then the note that is being played if your port volume is to low.

If it is to high your output will be slightly less the same gain and the pressure (air movement) will be lacking. (Like I said you just have to know)

If your net volume is to high you will get more of a "squashed" responce from the driver.. kinda like it is baffled, which will diminish by increasing the gain.

If your net volume is to low you will get more of a "poppy" responce from the driver, in which th edriver may seem like it is being pushed to hard.

Hope this helps.

 

[fwb_1234 10+ year member]

Are you doubting the box already?

 

[Immacomputer 10+ year member]

I would first ask what it is about your setup that you don't like. Is it not loud enough? If so, at what frequencies? What songs don't seem loud? How do you have the sub and port firing?

Is it the 9 cubes at 40hz enclosure?

 

[baseballer1100 5,000+ posts]

we wan pics!!!

 

[SeanDub 10+ year member]

Haha, no, I'm not doubting the box already. And no, I'm not dissatisfied with the setup, I'm sure it's gonna be loud as hell, just havent got the time or money to finish it up just yet.

The only thing I'm seriously doubting is the port area. After all displacements the box is going to be closer to 10 cubes net, but with only 110 inches squared of port.

Not doubting, just thinking that it might not have been the best design in the world to try for a first box.

*pics tomorrow*

 

[Relax 10+ year member]

Why do you think you need more port area?

 

[galacticmonkey 5,000+ posts]

how do you have a DD 9917 and now know how to design a simple box? //content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif

 

[Death By Bass 10+ year member]

only 110inches of port? thats over half the woofers cone area, if anything, I'd be saying its too big.

I reckon the box is too big, thats for sure.

edit: whats it tuned to?

 

[galacticmonkey 5,000+ posts]

Im just wondering why you bought a 9917 if you care how it sounds at all? These arent exactly known as musical woofers... Hell, ive only heard of 1-2 people actually ever play music on them.

 

[fwb_1234 10+ year member]

Here's a link to the build, we should start it up again about 4:00EST.

http://www.caraudio.com/forum/showthread.php?t=213985

 

[SeanDub 10+ year member]

how do you have a DD 9917 and now know how to design a simple box?

Because I knew they were unbelievable subs, and when i saw one being sold for cheap I picked it up. And I do know how to design a box you fu*ktard, I designed the one that's being built. However, I live in an area that's not inhabitated by many other kids with great setups and I was wondering how to tell if there are any problems with a box because if there are problems with my design, I would like a different one.

Im just wondering why you bought a 9917 if you care how it sounds at all? These arent exactly known as musical woofers... Hell, ive only heard of 1-2 people actually ever play music on them.

Ah well hell. You must know it all. Yeah, well I want you to wander over to http://www.realmofexcursion.com, click on the videos link the top right corner, scroll down to Digital Designs, watch the two videos of 9917s, one by Nick at Sick Audio and one by BlueLax, and tell me what they're playing. Is it test tones? Is it a bass cd? No, it's I'm Sprung chopped and screwed and some emo rock song.

Further, this is what the DD website says:

Versions of these woofers have been optimized for use in high-end home audio to ultra high power competition use. These drivers are equally at home pounding out bass lines on the street, setting spl records around the world or capping off the ultimate home theater system

So I dunno where you thought they were just loud subs or that I cant design a simple box, but please dont post dump. It's bad for your health.