To all current enclosure designers: a proposal

[PV Audio 5,000+ posts]

I'm adding a poll since I think this thread might go for a few pages and entrants might get lost in the myriad of unrelated posts.

 

[Buck 5,000+ posts]

I do this when I'm at home with my testing equipment, but I don't have any of that up here at school. Plus, I don't think Purdue wants me barging into the lab demanding use of a spectrum analyzer, function generators and a $15,000 oscilloscope for an internet contest //content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

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Whose designs have been flawed?

 

[Upgrayedd 10+ year member]

What part of indy are you in? Is this mystery 3rd party one of the few designers/engineers that live/lived in the fishers/Indianapolis area?

 

[DonH 5,000+ posts]

im in! i think to make it the best you should pick a size of driver, make and model, since every box's design is for a certain driver. Also what kind of goals should the box achieve, what vehicle or what the vehicle peaks at, etc. make it to where the re-box calculator lovers have zero chance! do that then i will be in to prove.

-Don

 

[Pioneer~Saturn 5,000+ posts]

Im in..

 

[80INCHES 5,000+ posts]

im down

80

 

[PV Audio 5,000+ posts]

im in! i think to make it the best you should pick a size of driver, make and model, since every box's design is for a certain driver. Also what kind of goals should the box achieve, what vehicle or what the vehicle peaks at, etc. make it to where the re-box calculator lovers have zero chance! do that then i will be in to prove.
-Don

They don't have a chance anyway since the RE calc isn't accurate //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

And as I said, there will be no testing of any enclosures. This is merely to see if you have the fundamentals of enclosure design. That's why I said to assume that the enclosure is in free space. I've gotten a PM from a home audio designer who doesn't do any car audio, and if you can design in a home, you can design in a car, but not the other way around. It's when you need to design FOR a specific car or person's taste that his knowledge lacks, but that's irrelevant for this proposal. You send me a design of a simple ported box, no frills, nothing. Easy, frankly.

 

[PV Audio 5,000+ posts]

What part of indy are you in? Is this mystery 3rd party one of the few designers/engineers that live/lived in the fishers/Indianapolis area?

He is an engineer, he has lived in Indianapolis, but he doesn't do car audio at all. However, along with maybe 2-3 (one of which is no longer here) people on here, he's the only person I've ever paid for a design in my life.

 

[PV Audio 5,000+ posts]

POTENTIAL APPLICANTS: READ THE FOLLOWING!!!

Okay, we need 2/3 more people to sign up for my number of 8. Once we hit 8, I'll post the requirements. I have decided to make it a bit more difficult just to weed out some people using a stolen program who sell things with port lengths of 50" for 1 cube boxes:

1. As stated, the design is for a simple slot ported box. However, I have decided to change something. Your design will be rated out of 100 points. I will normalize everyone's scores to the highest score (if 1.87/2 cubic feet is the closest, then that's the highest score. Please be more accurate than that though //content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif) to guarantee a winner, as long as at least 3 peoplea re within 75% accuracy. This portion is as I've stated so far: build a simple slot ported enclosure to a given tuning and enclosure volume. This portion will be rated out of 75 points.

2. The second part is partially subjective and mostly objective. The enclosure will still be a simple slot ported box, but I want you to take into account a specific driver when you do your design. This way, if you're running an AudioPulse REVO in the same enclosure that can fit a Sony Xplod, you will be able to differentiate the enclosures. This is also done to showcase people taking bracing and other internal structures into account. More importantly, it proves to me that you have intuition about enclosure design and aren't just using an online calculator. You could get away with 8sq in of port on that Sony, but the REVO would compress that port into a pancake. I will post the driver when I post the enclosure specs. Assume that the driver is being given rated power and is again operating in free space. This will probably require you to at least glance at the T/S parameters of the speaker. This is rated out of 25 points.

NOTE: Parts 1 & 2 are for the SAME design. You take into account BOTH. I'm just grading your accuracy for 75% and your intuition for 25%.

Finally, I am adding another section to the test entirely that is 100% optional. This section is 100% subjective and is going to be based on a single speaker in any enclosure you want at any size you want at any tuning you want (if it needs to be ported). The idea here is to show that instead of just being able to work a simple formula, you understand how speakers work in enclosures. Assume for this portion, the system will be operating in a large room with damped floors and walls, so no reflections need to be taken into account. Baffle mechanics, however will be. That means you need to consider baffle step, lobing and diffraction among other things. Since I know many of you guys aren't even interested in things this complicated, that's why this is 100% optional and is worth $15 for first and $5 for second. No third place will be judged. I will list the speaker to use when I list all the other parameters. Assume that the driver has an ideal filter and you only need to optimize the enclosure to the speaker and not any internal circuitry. This will be for an obscure driver that many of you may have heard of, but that's only to ensure that there are no published ideal parameters. You'll have to do that yourself. I just have to ask that if you are uncomfortable with this portion, then don't bother doing it. Don't waste your time learning what takes years over the course of a week. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

Note that the first portion's driver being used for this is well known, but may NOT be necessarily car audio drivers. That way, no one has an inherent advantage such as if Incriminator enters and I choose DP12 or TeamPsi send in a design for a SX15.

So, that's basically it. If you want to enter both, please let me know. To make it fair to everyone who does car audio, you can only enter the optional portion if you're doing the slot ported design as well. That way we don't get any guys coming over from avsforum or diyaudio and stealing my 15 dollars. //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif

-Dave //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[Upgrayedd 10+ year member]

Thought you may have been referring to Deon but he does car audio now and I don't see him charging for an enclosure.

 

[46panel 10+ year member]

O good I wanted pioneer saturn to be in since he did two of mine!

 

[IDSkoT 5,000+ posts]

Haha... hilarious.

I always quadruple check my designs for accuracy. No one's ever complained... and every enclosure I've built sounds beautiful.

 

[Pioneer~Saturn 5,000+ posts]

O good I wanted pioneer saturn to be in since he did two of mine!

Lol //content.invisioncic.com/y282845/emoticons/banghead.gif.8606515f668c74f6de0281deb475b6fd.gif

 

[PV Audio 5,000+ posts]

Haha... hilarious.
I always quadruple check my designs for accuracy. No one's ever complained... and every enclosure I've built sounds beautiful.

You in? I'll be sending some PMs to people I know just in case they don't see this thread. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[Toxic Tuan 10+ year member]

Hi guys,

Please take no offense in post but let me state my opinion.

designs of pure enclosure and subwoofer TS parameters are very useless. 50% of the enclosure design revolves around the cabin/evirornment. 30% Revolves around application. 10% includes the personal preference of the listener and the last 10% is dependent upon theory. I've designed enclosures that was tuned to 70 hertz and the end result was an RTA-ed perfect linear flat response down to 25 hz due to the applications and environment. There are no current market available software that can calculate this. I use my own software that I've created to account for the factors involved. Pete from PWK Designs has an astonishing software that accounts for response in the time domain with particle collision theories that goes way beyond any software available.

In all honesty, I would assume that everybody can do basic designs using WINISD, BassBox Pro, Leap, etc. I would call it calculating. But I wouldn't call that designs. Designs require extensive knowledge of the entire system with the emphasis of it's application.

I'm expecting that every so called designer should get 100%, +/- 1% error round off, accuracy with this challenge. However, my proposal to a true challenge would be designing a subwoofer enclosure with one specific subwoofer that will would be measured in one vehicle. Then the design would be subject to the RTA for accuracy. This is a true design challenge.

Tuan