Trunk 4th order build

[95Honda 486]

Pretty much a stab in the dark then, good luck...

[97maxima 9]

Pretty much a stab in the dark then, good luck...

Yes and no, you can model anything you want but once its in the vehicle things change. rather build and mod. Ive had some pretty successful builds that way.

[95Honda 486]

Yes, that is a common misconception in car audio.  The actual alignment doesn't change in the cabin, and the output can be predicted.  Lance Dickson did some pretty extensive testing with this a decade ago, comparing Qtc in and out of a confined environment.  Changes were less than 5%.  Everything can be modeled as far the actual alignment output...

 

But again, good luck.

[97maxima 9]

Yes, that is a common misconception in car audio.  The actual alignment doesn't change in the cabin, and the output can be predicted.  Lance Dickson did some pretty extensive testing with this a decade ago, comparing Qtc in and out of a confined environment.  Changes were less than 5%.  Everything can be modeled as far the actual alignment output...

 

But again, good luck.

And if we could model everything there would be no need to test. everything would be a one shot build. we would have 20 craig butlers. I rough design for volume and tuning on "paper" then built ,test, and mod. Ive had many successful loud daily and spl builds. All from testing. No luck needed. Luck is builds that hit certain numbers and never get louder.If your knowledge of building and testing out weighs mine please feel free to contribute. Otherwise if your certain computer modeling is the way to go you have expressed it thoroughly and you have no further need to post about it in my thread.

[antoinez28 62]

Great build I like it makes me want to try a build like this and hows your front stage

[97maxima 9]

Great build I like it makes me want to try a build like this and hows your front stage

Its been fun and aggravating at the same time building in the car. Im running Pioneer tsd1720c 6.75 comps on a ppi ion 520.4. Very happy with them

[swift 501]

Looks good

[95Honda 486]

 

Yes, that is a common misconception in car audio.  The actual alignment doesn't change in the cabin, and the output can be predicted.  Lance Dickson did some pretty extensive testing with this a decade ago, comparing Qtc in and out of a confined environment.  Changes were less than 5%.  Everything can be modeled as far the actual alignment output...

 

But again, good luck.

And if we could model everything there would be no need to test. everything would be a one shot build. we would have 20 craig butlers. I rough design for volume and tuning on "paper" then built ,test, and mod. Ive had many successful loud daily and spl builds. All from testing. No luck needed. Luck is builds that hit certain numbers and never get louder.If your knowledge of building and testing out weighs mine please feel free to contribute. Otherwise if your certain computer modeling is the way to go you have expressed it thoroughly and you have no further need to post about it in my thread.

 

 

Look, this forum is about learning.  Sometimes people will point things out that may help, don't get defensive.  Other people will be reading this thread and may learn something.  I asked a simple question because I was curious and looking for insight.  I made a comment about objective data.  No reason to get defensive.

 

Again, the build looks good and good luck with the outcome, this isn't a smart ass comment, it really means good luck.

[97maxima 9]

 

 

Yes, that is a common misconception in car audio.  The actual alignment doesn't change in the cabin, and the output can be predicted.  Lance Dickson did some pretty extensive testing with this a decade ago, comparing Qtc in and out of a confined environment.  Changes were less than 5%.  Everything can be modeled as far the actual alignment output...

 

But again, good luck.

And if we could model everything there would be no need to test. everything would be a one shot build. we would have 20 craig butlers. I rough design for volume and tuning on "paper" then built ,test, and mod. Ive had many successful loud daily and spl builds. All from testing. No luck needed. Luck is builds that hit certain numbers and never get louder.If your knowledge of building and testing out weighs mine please feel free to contribute. Otherwise if your certain computer modeling is the way to go you have expressed it thoroughly and you have no further need to post about it in my thread.

 

 

Look, this forum is about learning.  Sometimes people will point things out that may help, don't get defensive.  Other people will be reading this thread and may learn something.  I asked a simple question because I was curious and looking for insight.  I made a comment about objective data.  No reason to get defensive.

 

Again, the build looks good and good luck with the outcome, this isn't a smart ass comment, it really means good luck.

 

Sorry didnt notice you were trying to help. As you didnt ask anything about the build and its goals. Wasnt being defensive as i know im not wrong in my methods. I build, i test, i mod and test some more. As anyone thats ever built anything great does.

[95Honda 486]

Roger.  I may not have been trying to help you as much as other, more novice, builders.  You need to remember that many people are reading this thread, many with less knowledge than you.  So I would like them to understand that there are objective ways to begin a design, and they may find another route to go that will get them off on a solid footing.  The problem is, many will look at the fact that someone chose a band-pass ratio and ran with it without first checking how the drivers will behave.  You may be able to get away with this, many others will not.  It is important to remember, that while this is your thread, others are learning...

[///M5 2,833]

It doesn't help that you picked a trendy, mostly pointless alignment that nooblets often reach for to be different.

The information you have on modelling is completely false. Not only is it easy to do and accurate, but it is exactly how the car you built the box in was designed. The pretext of building X enclosures to try things out and see is absurd. I'd love to have you show us any shop that consistently puts out good installs that doesn't model their ported enclosures. I'll give you a hint, there isn't a single one anywhere in the world. Going from a standard 4th order ported to a BP ported doesn't really even complicate the math.

And please forget any "ratio". Anyone that recommends a ratio without knowing exactly what the driver is has no idea what they are doing and will fail miserably.

[edouble101 314]

You install looks good, much better than most. If you didn't achieve your goals with it, now you have a baseline!

[97maxima 9]

You install looks good, much better than most. If you didn't achieve your goals with it, now you have a baseline!

Thanks

It doesn't help that you picked a trendy, mostly pointless alignment that nooblets often reach for to be different.

The information you have on modelling is completely false. Not only is it easy to do and accurate, but it is exactly how the car you built the box in was designed. The pretext of building X enclosures to try things out and see is absurd. I'd love to have you show us any shop that consistently puts out good installs that doesn't model their ported enclosures. I'll give you a hint, there isn't a single one anywhere in the world. Going from a standard 4th order ported to a BP ported doesn't really even complicate the math.

And please forget any "ratio". Anyone that recommends a ratio without knowing exactly what the driver is has no idea what they are doing and will fail miserably.

There is not one size fits all single shot spl enclosure. What im doing and what a shop does when building someones daily beater is completely different. I never build numerous enclosures nor implied i was trashing this one. I build boxes that can be modded. Ports that can be modded. I built my enclosure as large as it possibly could be since its always easier to shrink than it is to make your enclosure larger. I think your way off base. Playing around with my 4th makes me a noob? Hardly 

Edited November 12, 2014 by 97maxima

[ssh 924]

 

You install looks good, much better than most. If you didn't achieve your goals with it, now you have a baseline!

Thanks

It doesn't help that you picked a trendy, mostly pointless alignment that nooblets often reach for to be different.

The information you have on modelling is completely false. Not only is it easy to do and accurate, but it is exactly how the car you built the box in was designed. The pretext of building X enclosures to try things out and see is absurd. I'd love to have you show us any shop that consistently puts out good installs that doesn't model their ported enclosures. I'll give you a hint, there isn't a single one anywhere in the world. Going from a standard 4th order ported to a BP ported doesn't really even complicate the math.

And please forget any "ratio". Anyone that recommends a ratio without knowing exactly what the driver is has no idea what they are doing and will fail miserably.

There is not one size fits all single shot spl enclosure. What im doing and what a shop does when building someones daily beater is completely different. I never build numerous enclosures nor implied i was trashing this one. I build boxes that can be modded. Ports that can be modded. I built my enclosure as large as it possibly could be since its always easier to shrink than it is to make your enclosure larger. I think your way off base. Playing around with my 4th makes me a noob? Hardly 

 

 

I'm a little confused as to why you don't think you can model the final response of the enclosure? Can't you model a sealed enclosure in free space then place it in the cabin and record the FR, the difference would be your cabin's effect on FR. Then model your 4th order bandpass ported enclosure in free space and apply the cabin effects to the FR to get the actual FR when it's in the cabin. I'm sure this isn't 100% accurate since there's a few variables at play, but surely it's got to be a better starting point than using arbitrary numbers?

Edited November 12, 2014 by ssh

[97maxima 9]

Never said you couldn't model . But personally i dont. Im not building a daily beater. I build for numbers, i run meca, which meters at the headrest with different combos of doors and windows open. Your peak will move around alot depending on this. Which is something you cant model. I build, test and modify. Example, my last single 15 build tuned to 36 hz, port firing into the cabin. Once i opened the trunk up,a few doors, and taped off the flare into the cabin the peak moved down the 31hz at the headrest. Your not going to be able to being modeling that. Not saying all of you are wrong. Its just not the way i do things, nor anyone i know that competes. Im here simply trying to show off a product. If any of you knew me you this would not even be coming into question. Not really sure why i build the way i do remotely matters enough to clutter my thread.

[95Honda 486]

I still don't think you understand what we are talking about, we aren't talking about the cabin gain, we are talking about your target alignment starting point.  This where you reliably predict system response and know what the actual output before cabin gain is.  It is loudspeaker 101.  It doesn't make sense to arbitrarily pick volumes as a starting point, we just want to make sure the novice readers understand this.   We aren't trying to clutter your thread, it is open for everyone.  We are trying to ensure more than just you learn from this.  Nobody is saying you can't design to your goals, we are just trying to let everyone understand that the approach isn't as objective as it could be...

[97maxima 9]

I still don't think you understand what we are talking about, we aren't talking about the cabin gain, we are talking about your target alignment starting point.  This where you reliably predict system response and know what the actual output before cabin gain is.  It is loudspeaker 101.  It doesn't make sense to arbitrarily pick volumes as a starting point, we just want to make sure the novice readers understand this.   We aren't trying to clutter your thread, it is open for everyone.  We are trying to ensure more than just you learn from this.  Nobody is saying you can't design to your goals, we are just trying to let everyone understand that the approach isn't as objective as it could be...

No i understand. Picking volumes does as its built in car. It can be shrunk on either chamber and loading walls and port inserts changed which is part of SPL building 101 where everything you build can be easily modified. Which is key to building anything loud. Its a fairly simple concept. This is very common in building and it may seem greek to you.Its called testing. We build, test, mod and test again. Yea you can model for a certain peak your looking to get near and thats fine and it will prob be close with the vehicle sealed. But once you start opening doors and windows and the peak starts moving around you can forget your modeling. No great spl builder sat down in front of his pc and crunched some numbers and instantly had a world record breaker. I really hope you guys learn from this because you seem pretty clueless.

[95Honda 486]

We aren't saying you design an alignment on a computer and go with it without change, we are simply trying to get people off on an abjective start.

 

When I was working with some of the MECA competitors in the early 2000's (about 200 or so complete builds ago) we would objectively start with a modeled design and then test/tweak from there.  We did not arbitrarily start with volumes on a guess, we would still see how the loudspeakers were going to act as a starting point.

 

Case in point, I completed a high efficieny build in 2003 using the first generation RE 8s.  I was limited in power to roughly 150 watts.  I modeled a multi-tune (pluggable ports, 6 in totall) 4th order vented enclosure and had 3 predicted peaks that went with my 3 tunings.  I knew the modeled peak at the highest point was near the vehicle resonance (1978 full size Bronco) of 56Hz.  When I modeled for the intended peak to coincide near vehicle resonance I was able to net over 143db, at the headrest, on the Termlab, using 153 watts of total input power to my 8 RE8s (19 watts per driver).  This was all possible with little tweaking of the actuall alignment due to carefull planning and simulation.  And I was able to hit my peak SPL at 56Hz, as predicted by both alignment peak and vehicle resonance.  But again, I was only able to do this as easily as I did because I was fully aware of the alignment response BEFORE any actual testing...

 

Again, we have no doubt that you can build great SPL systems, we are trying to stress to the readers of this thread that there are more objective ways to start. 

 

Just think of how many unknown alignment variables you can eliminate by modeling first...

 

I have been doing this for well over 20 years and I still learn new things everyday.

[97maxima 9]

We aren't saying you design an alignment on a computer and go with it without change, we are simply trying to get people off on an abjective start.

 

When I was working with some of the MECA competitors in the early 2000's (about 200 or so complete builds ago) we would objectively start with a modeled design and then test/tweak from there.  We did not arbitrarily start with volumes on a guess, we would still see how the loudspeakers were going to act as a starting point.

 

Case in point, I completed a high efficieny build in 2003 using the first generation RE 8s.  I was limited in power to roughly 150 watts.  I modeled a multi-tune (pluggable ports, 6 in totall) 4th order vented enclosure and had 3 predicted peaks that went with my 3 tunings.  I knew the modeled peak at the highest point was near the vehicle resonance (1978 full size Bronco) of 56Hz.  When I modeled for the intended peak to coincide near vehicle resonance I was able to net over 143db, at the headrest, on the Termlab, using 153 watts of total input power to my 8 RE8s (19 watts per driver).  This was all possible with little tweaking of the actuall alignment due to carefull planning and simulation.  And I was able to hit my peak SPL at 56Hz, as predicted by both alignment peak and vehicle resonance.  But again, I was only able to do this as easily as I did because I was fully aware of the alignment response BEFORE any actual testing...

 

Again, we have no doubt that you can build great SPL systems, we are trying to stress to the readers of this thread that there are more objective ways to start. 

 

Just think of how many unknown alignment variables you can eliminate by modeling first...

 

I have been doing this for well over 20 years and I still learn new things everyday.

Maybe you should start a thread someone educating people on the benefits of modeling. But you insist on mucking up MY build thread. Well ill inform you your living in the wayback machine then in pre 03. I can tell you right now any world champ in the recent isnt modeling but testing.And im familiar with the winners in nearly every class. Its great thats how you do things and your buds do the same, its awsome. But i seriously think your parading you ways in the wrong place. please go start your own thread elsewhere 

[95Honda 486]

Hey man, first off, nobody is trying to muck up your thread.  You don't have to take this to a personal level in your posts.  Nobody has disrespected you.

 

We wanted to inform the readers of different avenues of design, and we did that.  You question our knowlege and skills without conducting proper research.

 

Please don't take this as disrespect, because it isn't.  This is a public forum.  We will point these items out as they arise, it isn't a personal attack.

 

I think the readers get the point, there isn't any reason for me to post about it anymore, so I won't.

 

Good luck with your build!

 

-Mike

[nadcicle 77]

As someone just observing this thread I see value in both of your views.

 

Build is looking good too! 

[jcarter1885 995]

Meh....this thread went south real quick

Edited November 12, 2014 by jay-cee

[///M5 2,833]

Maybe you should start a thread someone educating people on the benefits of modeling. But you insist on mucking up MY build thread. Well ill inform you your living in the wayback machine then in pre 03. I can tell you right now any world champ in the recent isnt modeling but testing.And im familiar with the winners in nearly every class. Its great thats how you do things and your buds do the same, its awsome. But i seriously think your parading you ways in the wrong place. please go start your own thread elsewhere

It is dumbfounding to me that you even think there is a need for explanation. EVERY car is modelled first BEFORE it is built. Perhaps you should go inform all of the OEM manufacturers why they don't need to model. I can tell you the platform manager for the Impala you drive will laugh his ass off at you, if it helps I can introduce you.

Pretty funny that the world champs bluffed you out. If they don't do something as simple as modelling that is rather laughable.

[Fi 4 life 0]

Meh....this thread went south real quick

I agree, he was just showing people in this hobby what he is working on, he wasnt asking for recommendations or for someone's approval.

Personally I like to see what my response looks like, but I'm not going for numbers and I dont have a SPL meter so I rely on software and eq

Good luck with your build and in the next coming season!

[97maxima 9]

 

Maybe you should start a thread someone educating people on the benefits of modeling. But you insist on mucking up MY build thread. Well ill inform you your living in the wayback machine then in pre 03. I can tell you right now any world champ in the recent isnt modeling but testing.And im familiar with the winners in nearly every class. Its great thats how you do things and your buds do the same, its awsome. But i seriously think your parading you ways in the wrong place. please go start your own thread elsewhere

It is dumbfounding to me that you even think there is a need for explanation. EVERY car is modelled first BEFORE it is built. Perhaps you should go inform all of the OEM manufacturers why they don't need to model. I can tell you the platform manager for the Impala you drive will laugh his ass off at you, if it helps I can introduce you.

Pretty funny that the world champs bluffed you out. If they don't do something as simple as modelling that is rather laughable.

 

Lol  i think your high as a kite. I never asked for a explanation of anything nor your input or anyone else on modeling. Your taking this out into left field went from my 4th order to GM modeling a impala. As far as anyone bluffing me your foolish to think that. Anyone that knows anything about SPL its testing and building. Especially in the org i run. im done trying to reason. You guys are pretty hard headed. But ill keep you updated on how my non computer modeled build goes