Burp box...

[shredder1 10+ year member]

Finally settled on a configuration that should work, sound pretty good and be able to get fairly loud... This looks crazy but will be 3 ft3 net /w/ 74 in2 ported tuned to 40 hz...

It took me awhile to digest all the advice I've gotten and once it sank in I saw what everyone was talking about while modeling the enclosure... this should do well at the cabin frequency...

Man that port IS big and LONG... I'd have never thought to do it this way without the advice from certain members... Thanks again... this might end up as a pretty good daily box as well...

I'll post what happens Wednesday... unless the Cops are going to cause problems at the Bassmeet like last week... LOL!

 

[shredder1 10+ year member]

All pre-drilled and marked... anyone see any obvious problems?.. tomorrow I'll fight through the assembly and probably just spray paint it black...

I'm glad I've got grown kids to help me with the manual labor involved... LOL!

Do the 45's look to be in the correct corners?.. I only added them where the box was small or opposite the port.

I'll paint it tomorrow and take my time... I've got till Wednesday evening... I will post impressions/results later this week...

 

[shredder1 10+ year member]

Installed and first impressions are good... it increased for sure... sounds good too... tuned to 41 hz and peaks at 51 hz which is right at cabin frequency... The local bassmeet tonight is minus the host as he looks to secure a new location... the cops rousted everyone right after I left last week... so I'll wait till Sunday to meter it... but it definitely has gained and has a better range of frequencies... it's a Daily/SPL box and everyone who has demoed today has noticed a BIG increase... no predictions tho... I'm not going there, that meter is tough... LOL!

 

[Boomin_tahoe 5,000+ posts]

ookin' good boss.....btw, that's an awefully small kitchen.

 

[kr15 5,000+ posts]

Looks good. Curious to see how it does

 

[Boomin_tahoe 5,000+ posts]

Wait a sec....I just noticed his rear window mdf piece holding it up lol. I'm guessing the actuators are worn out. Can get those at the store...like 10-20 bucks each.

 

[Boomin_tahoe 5,000+ posts]

My blazer I used to have...



The audio..

 

[shredder1 10+ year member]

The wait is killin' me... I suppose I COULD meter it tonight but I'm not that keen to have a conversation with Mesa PD over unauthorized usage of the mall property... it's a dying mall with about 10 or less stores still open... I believe it's under new ownership and the lights go out after mall closing so that parking garage is DARK and the cops do not like a gathering under those conditions... I was metering up to 149.2 outlaw before... now it gets substantially louder and keeps increasing at an nice smooth rate.... I can bring the sub gain up quite a bit at full volume now without voltage drop... before I had some voltage drop above 147-8, and I rarely touched the sub level.... now it seems to use the voltage available much better and does not drop voltage till I'm way past the previous 148-9... I think tuning at 47-50 was too narrow and the excursion was way past cabin frequency... tuning lower was the answer... the response peak AND excursion is now peaking close to the cabin frequency, before the excursion was about a third of where it models at cabin frequency now.... It's using that power MUCH better... Changing that port location will help I'm sure... I'm hoping for at least a 150, but at this point anything over 149.2 is a gain... so I'll be happy, I'm sure...

 

[shredder1 10+ year member]

Wait a sec....I just noticed his rear window mdf piece holding it up lol. I'm guessing the actuators are worn out. Can get those at the store...like 10-20 bucks each.

Yeah... they lost all their charge and were rattling like crazy since they were just sitting there not pushing at all... I removed them

 

[kr15 5,000+ posts]

Excursion is least at enclosure tuning.

Rise is highest at tuning

 

[shredder1 10+ year member]

Excursion is least at enclosure tuning.
Rise is highest at tuning

Yes... I see the difference... I could have tuned it to 39 hz and both response and excursion would have been dead on cabin peak, but it is really close now... I've got it tuned at 41.44 hz now and the difference is unreal to me... now I need an APM-2 to chase down any more gains... maybe eventually I'll afford one... next year maybe?

 

[hispls 5,000+ posts]

Rise is highest at tuning

False. In ported box that is the lowest point.

I'm hoping for at least a 150, but at this point anything over 149.2 is a gain... so I'll be happy, I'm sure...

Outlaw doesn't count.

http://jahonen.kapsi.fi/Audio/Papers/AES_PortPaper.pdf

Worth a read if you want information from actual engineers and experts on the subject who have testing and math to back up what they say.

 

[shredder1 10+ year member]

False. In ported box that is the lowest point.

Outlaw doesn't count.

http://jahonen.kapsi.fi/Audio/Papers/AES_PortPaper.pdf

Worth a read if you want information from actual engineers and experts on the subject who have testing and math to back up what they say.

It got louder overall... at least I did not lose output... anyways, it looks like you are correct...

 

[shredder1 10+ year member]

"Outlaw?"... it is something totally new to be anyways... in IASCA when I competed in the 90's the ONLY way to meter was sealed on the dash... I'm still getting used to the concept of "Outlaw"... I hear ya' man, same thinking as mine, I'd love to do a 150 sealed up but I'll take what I can get... heck, it's only 2 12's and a $798 sub/amp combo...

 

[hispls 5,000+ posts]

"Outlaw?"... it is something totally new to be anyways... in IASCA when I competed in the 90's the ONLY way to meter was sealed on the dash... I'm still getting used to the concept of "Outlaw"... I hear ya' man, same thinking as mine, I'd love to do a 150 sealed up but I'll take what I can get... heck, it's only 2 12's and a $798 sub/amp combo...

Not sure where the name came in, but outlaw measuring has been around for a while, the "big" org that meters door/window open at the kick is USACi.

Buy yourself Dayton DATS and see how close your predicted impedance plot matches reality. Alternately, you're welcome to borrow mine if you pay shipping both ways.