Burp box...

[LosIsATool 5,000+ posts]

I got a warning. Don't do it. Once you get on that path it leads to disappointment unless you are ready to drop a lot of cash.

 

[shredder1 10+ year member]

I got a warning. Don't do it. Once you get on that path it leads to disappointment unless you are ready to drop a lot of cash.

What's the difference?... I dropped $$$ into SQ before with only local results... I was OK with that... LOL... It's going to cost me some sweat and anguish I'm sure... but all the equipment and materials are here... and PAID for... It's just an experiment... and I'm walking in with my eyes wide open... not looking to set records... there is some guy in AZ that does 164+ with 2 DD 15's in a CRX... I'm NOT setting my goals THAT high

 

[LosIsATool 5,000+ posts]

What's the difference?... I dropped $$$ into SQ before with only local results... I was OK with that... LOL... It's going to cost me some sweat and anguish I'm sure... but all the equipment and materials are here... and PAID for... It's just an experiment... and I'm walking in with my eyes wide open... not looking to set records... there is some guy in AZ that does 164+ with 2 DD 15's in a CRX... I'm NOT setting my goals THAT high

If you are serious about it then pick a realistic class and don't build out of it. Do everything that is allowed in it. If it has a frequency cap and you can match it do it. Don't worry about people making fun of the fart box, a win is a win.

 

[shredder1 10+ year member]

If you are serious about it then pick a realistic class and don't build out of it. Do everything that is allowed in it. If it has a frequency cap and you can match it do it. Don't worry about people making fun of the fart box, a win is a win.

I agree with that... I'm not planning to compete as far as I can predict... Just personally want to see where I can get it to... I'm fortunate to be in PHX where a SSA or Termlab meter is there for all to use TWICE a week... Maybe I'll buy something after all... Gorilla tape...LOL!

 

[LosIsATool 5,000+ posts]

I agree with that... I'm not planning to compete as far as I can predict... Just personally want to see where I can get it to... I'm fortunate to be in PHX where a SSA or Termlab meter is there for all to use TWICE a week... Maybe I'll buy something after all... Gorilla tape...LOL!

Imo no point in doing it unless you put it on the feild.

 

[Jeffdachef 5,000+ posts]

Imo no point in doing it unless you put it on the feild.

by your logic that means there is no point in me grinding hard at the gym lifting if I have no plans on entering a competition? Thats pretty dumb. there's always a point in self improvement and beating personal records in anything you find fullfilling.

 

[shredder1 10+ year member]

by your logic that means there is no point in me grinding hard at the gym lifting if I have no plans on entering a competition? Thats pretty dumb. there's always a point in self improvement and beating personal records in anything you find fullfilling.

Was it you or Kr15 that I described that SQ car I demoed in 1998 with the tube amps that started me on the SQ road back then?.. well I found it and let me tell you this thing was magical...

http://milbert.com/autos/earl

 

[shredder1 10+ year member]

Imo no point in doing it unless you put it on the feild.

It is a form of rehab for me... my motor skills are still questionable... and the "Field" as you put it will be local bassmeets... IDK how Pensacola is... All I ever did there was chase tail when I was stationed at Ft. Benning and had some short leave or couldn't stray too far from the base due to readiness status... but out here there is a solid enthusiast community that meets twice a week... Anyways do you think that the box design will be all right if I enlarge the port significantly and keep the tune at 50 or so?.. more efficient?

 

[LosIsATool 5,000+ posts]

It is a form of rehab for me... my motor skills are still questionable... and the "Field" as you put it will be local bassmeets... IDK how Pensacola is... All I ever did there was chase tail when I was stationed at Ft. Benning and had some short leave or couldn't stray too far from the base due to readiness status... but out here there is a solid enthusiast community that meets twice a week... Anyways do you think that the box design will be all right if I enlarge the port significantly and keep the tune at 50 or so?.. more efficient?

Pensacola is a **** hole. I hear it was good at one time.

As for the box. Like you said, trial and error.

 

[LosIsATool 5,000+ posts]

by your logic that means there is no point in me grinding hard at the gym lifting if I have no plans on entering a competition? Thats pretty dumb. there's always a point in self improvement and beating personal records in anything you find fullfilling.

I was the same way when I was lifting. Lol. I'm excessive compulsive. But I'm working on calming that down. I don't really have a choice in the matter

But there is only one reason to build a burp box. It's not something you can use daily.

 

[TRaGiK 10+ year member]

Do yourself a favor and go ahead and buy a meter. I used to get together with a buddy/shop owner that has a meter, but doing it on his time quickly became a hassle (for both of us), as I'm constantly testing new things to see if it makes a difference.

Be prepared to be irritated often by chasing numbers. You'll love it one minute, and be ready to burn the car to the ground the next. //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

It's gonna get expensive. You'll upgrade equipment because you need just one more tenth. Goals will change frequently.

Originally I just wanted a 140. In a matter of days that went to 150. Now I'm at 50, and I'm thinking about 55's...with a wall.

 

[YukonXL04]

Yea get ready for a lot of trial and error. I remember my blazer, different boxes, amps, alts, batts, deadener lol... I remember spending like 300 on deadener and lost 1.5db lol boy I was pissed!

Your current stage is a prime example of why I haven't metered my DD yet, I'm pretty sure it's under a 150 right now. If I end up metering it, I know I will end up messing with it a lot to try to get a higher score and right now I just don't feel like doing that. But more power to you! Hope you get your 150 or higher!

 

[hispls 5,000+ posts]

Was it you or Kr15 that I described that SQ car I demoed in 1998 with the tube amps that started me on the SQ road back then?.. well I found it and let me tell you this thing was magical...Milbert Vacuum Tube Car Amplifiers

400 pounds of deadener, EQ, time alignment, and those speaker locations.... it's not the amps that made that one sound good.

Originally I just wanted a 140. In a matter of days that went to 150. Now I'm at 50, and I'm thinking about 55's...with a wall.

Guess what comes next? Spoiler alert... it don't come cheap!

Agreed though you won't get loud without a meter, there's simply too many variables to test. If you don't have set times where just you take a notebook and test and meter for an hour or two just metering a few times at a friendly meetup won't get you anywhere fast.

I thought about this all day today and I've decided to go all out chasing numbers for a bit... I have taken a lot of great advice... the recurring theme is test and test again... after all the info I've learned I've decided to really start testing a few theories of mine... the suspension on these EVL's is pretty firm and I'm thinking I could increase the port area drastically to make it more efficient at a narrow frequency... I will watch my SSF settings as the last thing I want is to bottom these subs out at high volume... but the box is no longer going to be used musically and I will focus on the 50 hz to 55 hz region... I've already come up with a way to increase port area without changing the box width and still be able to decrease the port area as testing continues quickly and easily...the box width cannot change as it DOES fill the area between the wheel wells almost perfectly... I'll start with a larger area and use inserts to decrease it with time... I can start as high as 100 in2 realistically but have not decided a starting point (it may be less... 86 in2)... If i can model the velocities with up to 3500 watts as the input signal and keep the port velocity at or under 30 m/s... I'll try to use a port area in that neighborhood... Those CAB's at 1/2 ohm can put down some power... I just don't know how much realistically I can expect on my electrical... I am hoping this major port area increase will really let me use the power available at a narrow frequency... the car is dead and sealed pretty good so now I think efficiency is going to be the biggest factor... Here in Phx... I am fortunate to have twice a week meets with a meter usually available so testing is really NOT a problem... Anyone have any tips or thoughts before I do this box surgery?.. I cannot build another without hitting up Lowe's but I do have sufficient scraps just waiting to be put to use... and any input,warnings or thoughts will be welcomed...

You should not be reaching mechanical limits on those subs at 1500W at 50hz. Ignore everything on your modelling software except for where the peak frequency is. Logic won't help you too much if you're chasing 10ths. Read up on what others have done and test everything. Once you hit a point where you stop getting free gains (moving things around) Gorilla tape is 10$ a roll and should gain you somewhere, from there you'll pay for gains, and often you'll pay and loose. Good luck.

 

[shredder1 10+ year member]

Do yourself a favor and go ahead and buy a meter. I used to get together with a buddy/shop owner that has a meter, but doing it on his time quickly became a hassle (for both of us), as I'm constantly testing new things to see if it makes a difference.
Be prepared to be irritated often by chasing numbers. You'll love it one minute, and be ready to burn the car to the ground the next. //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

It's gonna get expensive. You'll upgrade equipment because you need just one more tenth. Goals will change frequently.

Originally I just wanted a 140. In a matter of days that went to 150. Now I'm at 50, and I'm thinking about 55's...with a wall.

Yeah... I followed your thread and it WAS quite epic and probably not over...LOL!... but I'm going to (or already have) give it a try... although as of this year I am DONE spending (except for X-Mas)... LOL!.. maybe some glue or tape... that's it!.. I'll try port area first then maybe start taping panels inside but NO EQUIPMENT... if I buy something and post about it... never let me hear the end of it... will Ya'... LOL!.. I'm just tryin' to see what I can get out of a $398 set of 12's and a $398 set of amps... this is therapeutic motor skill stroke rehab... audio style... I guess I've got too much time to kill... LOL!

 

[LosIsATool 5,000+ posts]

400 pounds of deadener, EQ, time alignment, and those speaker locations.... it's not the amps that made that one sound good.


Guess what comes next? Spoiler alert... it don't come cheap!

Agreed though you won't get loud without a meter, there's simply too many variables to test. If you don't have set times where just you take a notebook and test and meter for an hour or two just metering a few times at a friendly meetup won't get you anywhere fast.

You should not be reaching mechanical limits on those subs at 1500W at 50hz. Ignore everything on your modelling software except for where the peak frequency is. Logic won't help you too much if you're chasing 10ths. Read up on what others have done and test everything. Once you hit a point where you stop getting free gains (moving things around) Gorilla tape is 10$ a roll and should gain you somewhere, from there you'll pay for gains, and often you'll pay and loose. Good luck.

Don't forget the $7,000 interconnects.