Flashing tape inside a sub enclosure?

[fixinit]

What's up guys. Would there be any benefit to lining the inside of a ported box with a thin layer of butyl flashing tape? I've tried a poly-fil stuff and not stuffed and both are just too "boomy". My goal is to tighten up SQ. Any thoughts or science appreciated.

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[Slo_Ride 5,000+ posts]

I don't see how that would help. Without knowing your details you could add wood to decrease volume of your enclosure.

 

[fixinit]

I don't see how that would help. Without knowing your details you could add wood to decrease volume of your enclosure.

My bad. I'm running a 12" mofo in an undersized Belvia box tuned to manufacturer specs.

 

[Slo_Ride 5,000+ posts]

My bad. I'm running a 12" mofo in an undersized Belvia box tuned to manufacturer specs.

Many things can attribute to "boominess". EQ settings, box design and position, and lack of midbass all have any effect.

 

[fixinit]

Many things can attribute to "boominess". EQ settings, box design and position, and lack of midbass all have any effect.

Good points. I disconnected the sub for the day to figure out if my soundstage was on point and realized that my two front 6s and two rear 6x9s are collectively matched. The richness and clarity is almost perfect for my taste. But then when I accompanied my setup with the sub, mids get overwhelmingly muddy and the sub frequencies take over. It's hard for me to explain, but basically there's no sound continuity from 35hz-110hz (ballpark numbers).

I've installed this liner in a cheap 3-way home theater cabinet (10" sub), and it essentially muffled the lower frequencies which wasn't my intention. I just don't know how this kind of lining would react to something more powerful. I'm going to give it a go and see what happens...and I had one question before I start ripping the tape apart and forgot. Son of a

 

[Slo_Ride 5,000+ posts]

Good points. I disconnected the sub for the day to figure out if my soundstage was on point and realized that my two front 6s and two rear 6x9s are collectively matched. The richness and clarity is almost perfect for my taste. But then when I accompanied my setup with the sub, mids get overwhelmingly muddy and the sub frequencies take over. It's hard for me to explain, but basically there's no sound continuity from 35hz-110hz (ballpark numbers).
I've installed this liner in a cheap 3-way home theater cabinet (10" sub), and it essentially muffled the lower frequencies which wasn't my intention. I just don't know how this kind of lining would react to something more powerful. I'm going to give it a go and see what happens...and I had one question before I start ripping the tape apart and forgot. Son of a

The tape certainly won't hurt so...

 

[fixinit]

The tape certainly won't hurt so...

Thanks for the mind stimulation. Tight Dodge Charger btw.

 

[Boomin_tahoe 5,000+ posts]

What's the enclosure specs?

Oh wait...you said it was undersize. I say build another one with less boomness.

 

[fixinit]

What's the enclosure specs?
Oh wait...you said it was undersize. I say build another one with less boomness.

I'd love to and might in the future, but don't want to weigh my trunk down more than it already is. Combined, the weight of the sub and box is 53lbs. I even took out my spare tire to help my car out and that weighs in at 35lbs. I'm cutting corners and I know it but my system is run by a POS HU, so at the moment I'm attempting to find the best way to thump clean and still get the most out of what I have. Not sure how much longer this vehicle is running for. Hit 313k today.

 

[Boomin_tahoe 5,000+ posts]

Wow 313K miles?! I thought my s10 blazer was bad....had around 330k+++ miles. Lost track because I had to replace the instrument cluster, twice.

Are you or did you use MDF? You could try birch wood. more $$ but weighs a lot less than MDF.

Exactly what I did in my Tahoe. The subs by themselves are 50 lbs each. So that's 100 lbs except enclosure. So I'm guessing I got about 150-175 lbs in the back. Built the enclosure from birch ply to save weight.

 

[Slo_Ride 5,000+ posts]

Thanks for the mind stimulation. Tight Dodge Charger btw.

You're welcome

 

[trumpet 5,000+ posts]

Boomy bass is caused by a peak in the response in the upper bass/midbass region, in conjunction with not enough sub bass, all of which is compounded by an undersized enclosure. Without building a proper enclosure for the response you want, what could help is one band of parametric EQ. EQ the peak down.

The two things you will do by lining the inside with flashing tape are to seal off pores in the wood, if any, and to take away a minuscule amount of volume.

 

[fixinit]

Wow 313K miles?! I thought my s10 blazer was bad....had around 330k+++ miles. Lost track because I had to replace the instrument cluster, twice.
Are you or did you use MDF? You could try birch wood. more $$ but weighs a lot less than MDF.

Exactly what I did in my Tahoe. The subs by themselves are 50 lbs each. So that's 100 lbs except enclosure. So I'm guessing I got about 150-175 lbs in the back. Built the enclosure from birch ply to save weight.

330k miles+? Sick! Instrument cluster isn't a bad replacement compared to a front differential or transmission failure. My pre-fab is MDF but never thought of birchwood. I'll check that out if this lining doesn't jive with my buds.

Boomy bass is caused by a peak in the response in the upper bass/midbass region, in conjunction with not enough sub bass, all of which is compounded by an undersized enclosure. Without building a proper enclosure for the response you want, what could help is one band of parametric EQ. EQ the peak down.
The two things you will do by lining the inside with flashing tape are to seal off pores in the wood, if any, and to take away a minuscule amount of volume.

trumpet, thanks for the explanation! My HU has a built in parametric EQ, and to make things more complicated, the firmware associated with the deck doesn't support the "Sub"--only "Rear". So basically my line out to my sub is set on "rear" and EQ is set at 100Hz with wide or narrow range parametric settings influencing not only my 6x9s, but also the subwoofer. JVC didn't care to make things right with an update and now I'm pretty much forced to buy a new head unit if I ever want things to come together exactly as planned.

As for volume and lining. If by volume you mean making the enclosure smaller, the thickness of lining I put in is so thin, I can't imagine it having much of an impact on airspace or even tuning, but more sound dampening if it works. In theory it doesn't make sense. And I bet it won't help. But hoping it doesn't make it worse.

 

[trumpet 5,000+ posts]

As for volume and lining. If by volume you mean making the enclosure smaller, the thickness of lining I put in is so thin, I can't imagine it having much of an impact on airspace or even tuning, but more sound dampening if it works. In theory it doesn't make sense. And I bet it won't help. But hoping it doesn't make it worse.

No, there is not going to be any worthwhile damping happening from this stuff. I wouldn't do it. All it's going to do is add a little bit of mass.

 

[fixinit]

No, there is not going to be any worthwhile damping happening from this stuff. I wouldn't do it. All it's going to do is add a little bit of mass.

I'm going to stop halfway through and take your word for it. I did the bottom before the port, rightside and half of the closest wall in the pic. Just for the record which is going to be obvious. When I knock on bare MDF vs MDF with lining, the lining sounds less "boomy" with a higher pitch. I can't assume this is going to have any effect when things are in motion. Let me install and I'll get back with results.

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