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(Misconceptions??)

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I have heard systems at competitions that were ungodly loud and shook the ground but didn't hit a high number get beaten by the smaller systems that didn't sound like much but took the higher score. This is where most of the complaints to the judges originate. It's a sore topic for many. The meter and the ear are quite different.

Exactly my point.. Thats how Iam. I play music in the 150's but to play a tone all sealed up with mic on the dash.. It wont be very impresive. You know what Im talkin about man.. Good job.. you get brownie points :D haha

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The meter tells how loud it is. Period.

People complain when they think they are louder than they (actually) are, that's all......

People also forget that the meter is often in a different place than your ear....

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look at that for once I had a interesting topic (haha)

Just funny how many misconceptions there are out there.

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I have heard systems at competitions that were ungodly loud and shook the ground but didn't hit a high number get beaten by the smaller systems that didn't sound like much but took the higher score. This is where most of the complaints to the judges originate. It's a sore topic for many. The meter and the ear are quite different.

A lot of that is the difference in peak frequency.

My suburban - (2) systems, both did 157.7. One at 45 Hz, one at 36 Hz. To the ear, the 36 Hz system KILLED the 45 Hz system.

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I have also noted lower notes sounding louder to the ears. I have seen alot of people dissapointed by the lower numbers the low frequencies will throw up...

I also like the idea of the reality score where the jig puts the mic right in front of the headrest... This best measures what the driver will really hear...

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Misconception, 15's 12's etc... will always be louder than 10's! HAHA

Everything boils down to the install, box, tuning, testing etc...

Yes, I use 5k daily and love every minute of it! LOL

I'm with MLStrass on this Show me a 200watt system doing 145+ sealed on the dash. Not outlaw, in the port or whatever!

Thumper, interested in building me a new box?

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I have heard systems at competitions that were ungodly loud and shook the ground but didn't hit a high number get beaten by the smaller systems that didn't sound like much but took the higher score. This is where most of the complaints to the judges originate. It's a sore topic for many. The meter and the ear are quite different.

Exactly my point.. Thats how Iam. I play music in the 150's but to play a tone all sealed up with mic on the dash.. It wont be very impresive. You know what Im talkin about man.. Good job.. you get brownie points :D haha

When you say you play music in the 150's but sealed you get poopoo how do you meter your setup?

With windows open I play music well into the low 50's, sealed 148+, in the kick 152+, in the port (6 inches inside a 29.5in port) 164.5.

Just wondering.

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Its wierd.. I can meter 154 on the dash with windows down but the minute I roll my windows up the subs start to cancel out and lose pressure building performance.. Its cuz I built my box around the geometry of my trucks acoustics with windows down. My box can play well into the 22hz range and have flat response throughout. Obviously, before the sound can arrive at the listening point, the transfer, resonance, and grouping of the sound waves originating from system is confined and subject to the acoustics of the container, whether that's your listening room or your vehicle cabin. Most speaker CAD programs (on an off-chance that one is actually used) tend to assume that the vehicle does not exist, that the box is aligned on-axis with the listening point., and that there's an open-air gap of precisely one meter in between the two... That's just not very realistic.In exploring this a bit further, we can establish that, unless you're willing to re-construct the room or alter the vehicle cabin, the geometry of container cabin is pretty much a constant. We can also establish that there's only so far that you can move about the perimeter of your listening area, especially in a vehicle, making the enclosure a constant as well. Our key variable becomes the hearing point - a speaker in an enclosure that will effectively couple the cumulative cone mass to it's respective listening environment cabin, at the target listening point the ear. I guess some will never understand true physics :(

Edited by Thumper

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Its wierd.. I can meter 154 on the dash with windows down but the minute I roll my windows up the subs start to cancel out and lose pressure building performance..

99% of the vehicle out there will meter higher with the windows down. . .

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I know the easiest way to blow a speaker is to under power it, so I ALWAYS keep my system at max volume. yo. . .

hehe

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Well lets see, with windows down I can do a 154. Windows up a 143. Thats more than 10db of loss. Hey Brian.. I take it you live in Texas right? Well I got a guy with my team that goes to Heat Wave every year.. Hes with 2loudcrew his names Joe Lobadoes. Next time you seem ask him about Thumpers system and what it sounds like with windows up. Im tellin you, with windows up the subs cancel eachother out and make a bottoming out sound. Now if I had designed my box alot differently it would have been able to do some good scores on a mic with windows up and on the dash. You need to see to believe what Im talkin about.

Edited by Thumper

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Well lets see, with windows down I can do a 154. Windows up a 143. Thats more than 10db of loss.

There was one car I couldn't sit in with the doors open. Once the doors were closed it wasn't impressive at all. So there is truth in your post :)

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Well lets see, with windows down I can do a 154. Windows up a 143. Thats more than 10db of loss. Hey Brian.. I take it you live in Texas right? Well I got a guy with my team that goes to Heat Wave every year.. Hes with 2loudcrew his names Joe Lobadoes. Next time you seem ask him about Thumpers system and what it sounds like with windows up. Im tellin you, with windows up the subs cancel eachother out and make a bottoming out sound. Now if I had designed my box alot differently it would have been able to do some good scores on a mic with windows up and on the dash. You need to see to believe what Im talkin about.

Same goes for my truck, when I want to listen to it loud the front two windows go down because its a huge increase in output especially in the low hz. Things really get shaking it seems like when the windows are down. Maybe this is why my 12" Q is often mistaken for way bigger setups, haha.

The Suburban on the other hand, is equally as loud if not louder to the ear when the windows are up as opposed to down. It's gotta be the drastic difference in cabin space/peak with my F150 vs the Suburban.

Boxes in the truck go sub forward port up, boxes in the Suburban go sub up, port rear.

EDIT:

Now I got to thinking, the Suburban being bigger and harder to pressurize has a higher peak I would assume. While the truck being smaller pressurizes faster/easier, therefore does it have a lower peak? It would explain why it's louder in the low range than the Suburban is, and vice-verse for higher notes which the Suburban is dominant on, right?

Edited by 5.4SPL

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Having windows rolled down reduces cancellation within the cabin, making the system louder. As BKOLFO4 said, 99% of vehicles will behave this way. It's usually only when most systems get above 155-160 db and into heavily modified vehicles does this change. There is a point in which a transition occurs between stopping cancellation with the windows down and losing extremely high pressure because the windows are down.

This phenomenon is well documented, just ask anybody who has competed in an outlaw competition. It has little to do with box design.

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Well lets see, with windows down I can do a 154. Windows up a 143. Thats more than 10db of loss.

There was one car I couldn't sit in with the doors open. Once the doors were closed it wasn't impressive at all. So there is truth in your post :)

Thank you sir. :D

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Its wierd.. I can meter 154 on the dash with windows down but the minute I roll my windows up the subs start to cancel out and lose pressure building performance.. Its cuz I built my box around the geometry of my trucks acoustics with windows down. My box can play well into the 22hz range and have flat response throughout. Obviously, before the sound can arrive at the listening point, the transfer, resonance, and grouping of the sound waves originating from system is confined and subject to the acoustics of the container, whether that's your listening room or your vehicle cabin. Most speaker CAD programs (on an off-chance that one is actually used) tend to assume that the vehicle does not exist, that the box is aligned on-axis with the listening point., and that there's an open-air gap of precisely one meter in between the two... That's just not very realistic.In exploring this a bit further, we can establish that, unless you're willing to re-construct the room or alter the vehicle cabin, the geometry of container cabin is pretty much a constant. We can also establish that there's only so far that you can move about the perimeter of your listening area, especially in a vehicle, making the enclosure a constant as well. Our key variable becomes the hearing point - a speaker in an enclosure that will effectively couple the cumulative cone mass to it's respective listening environment cabin, at the target listening point the ear. I guess some will never understand true physics :(

You realize you can (under certain circumstances) have more pressure in the cabin with the windows down, right?

The same way there is more pressure in a ported enclosure (at resonance) than a sealed one......

But, I guess you would have to understand physics... :)

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Completely understand that my friend. But this system is far different from any of my other ones.. So in a sense you would have needed to hear the differences between the 3 different systems in the same vehicle but the enclosures were all different. :D

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Will windows up or down change the peak frequency. I was at a comp and it peaked at 41 hz, with the windows up. and got a 144.1, later I did a run with the windows down and did 5 hz steps to see what it metered at. and at 25 hz it got 140.1 and i think it was a 142.somethin at 40~41 hz. I dont think it does a 140.1 at 25 hz with the windows up, but i havent tested it like that yet. Is it normal to gain db with windows down on low low notes (20-30ish), but gain db with windows up on higher low notes(40-55)?

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Anything's possible. As has been said, some of what having the windows down helps is cancellation. Cancellation can be frequency-specific.

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Cancellation is pretty much always frequency specific.

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