DB loss from flex

[MrFoca]

How much loss can I expect from flex ? Roof is flexing pretty bad, rear of my escape has been matted. Hopefully the roof will be done this week coming up. Numbers seem pretty low for what I have, anyone know first hand what to expect once I mat the rest of the SUV ? . Last SUV was dynamat everywhere before the system so it's hard for me to gauge on what I'm losing from flex so far.

Click to read more...

 

[Massive spl]

Might gain or lose .5-1db.... It can go both ways. What deadening your roof should do it bring your peak down 1hz or 2

 

[hispls 5,000+ posts]

You lose a shitload from panels flexing. Email Will at makeitlouder.com and ask (I know he knows off the top of his head). You'd be shocked at how much DB loss even 1/8" of panel flex translates into.

"Deadening" may or may not help much. To make a meaningful difference you're talking about welding in thick sheet metal, filling doors with concrete, or other extreme solutions.

 

[adulbrich 5,000+ posts]

Yes, some people have actually lost on the meter from deadening/reinforcing.

 

[Jeffdachef 5,000+ posts]

Majority will gain from roof bracing. Dont be afraid to brace that sh*t.

 

[MrFoca]

My 21 did 145.6 I feel that's pretty low compared to other systems I've had in the past. Roof flexes very bad. Been calling a line x company up the street from me to see if that would help the outside from flex. I'll take some videos

 

[MrFoca]

You lose a shitload from panels flexing. Email Will at makeitlouder.com and ask (I know he knows off the top of his head). You'd be shocked at how much DB loss even 1/8" of panel flex translates into.
"Deadening" may or may not help much. To make a meaningful difference you're talking about welding in thick sheet metal, filling doors with concrete, or other extreme solutions.

Did triple layer on my old suv and it seemed to hold up very well. But I did all of this before installed everything, kinda wish I did it opposite so I could of seen a difference on the meter.

 

[Jeffdachef 5,000+ posts]

My 21 did 145.6 I feel that's pretty low compared to other systems I've had in the past. Roof flexes very bad. Been calling a line x company up the street from me to see if that would help the outside from flex. I'll take some videos

Might be a completely different issue instead, most you'd be losing is a db or two. That 21 should take you up well past the 148 range pre-deadened

 

[MrFoca]

Mechman 270A alt. big3, 1/0 welding lead. Currently running a stetsom 3K3. All gains set properly no guessing going on. 21 is 8.4 tuned 32 with 120sqin port. It's not overly tall of a box. Seem to be at a standstill for some reason. It did the 145.6 on music not a tone also.

 

[Massive spl]

Your box is to small... Build 14-15cubes with 160" of port tuned to 32hz... Then report back

 

[MrFoca]

Your box is to small... Build 14-15cubes with 160" of port tuned to 32hz... Then report back

See I'm getting conflicting stories about this. Some people are telling me to go smaller CRX style with big port area. And some say go even bigger. I'm down for trial & error but buying wood will get old soon lol.

 

[Massive spl]

Who's telling you to go smaller then 8cubes with a 21" woofer? Try my recommendation first and if u don't like it cut that box smaller.. But I'm 96% sure my suggestion will slam and get u 148+ Last box I help a guy on I found him 5db :0

 

[MrFoca]

Who's telling you to go smaller then 8cubes with a 21" woofer? Try my recommendation first and if u don't like it cut that box smaller.. But I'm 96% sure my suggestion will slam and get u 148+ Last box I help a guy on I found him 5db :0

I know you have a loud setup. Not doubting you, just others have loud systems who are telling me to go smaller. Saying smaller box will be more Eficent in a larger area compared to a big box blocking the meter.

 

[Massive spl]

I know you have a loud setup. Not doubting you, just others have loud systems who are telling me to go smaller. Saying smaller box will be more Eficent in a larger area compared to a big box blocking the meter.

A smaller box will not be more efficient.. As long as u have the space for a 15cubed box... If it was me I'd cpillar wall... What vehicle u have?

Here's a cpillar me n a buddy just built in his trailblazer

http://www.caraudioclassifieds.org/forum/build-logs/204825-kinda-budget-trailblazer-cpillar-wall.html

 

[MrFoca]

2008 Ford Escape. Trying to stay away from a wall right now, once I get another car possibly wall it then.