Duct tape ans SPL

[T3mpest 10+ year member]

Physical damping of the box will reduce the impedance spikes. It will also reduce the peaks in the output of the box.. Its been done many times in home audio and in vented boxes I can't recall it EVER making anything louder. When measured usually you just see a flatter overall response with smoother roll off. Subjectively it cuts down on a lot of the higher order distortion as well, sounds cleaner. Can't see it having a purpose in a SPL design.

As you already mentioned the impedance peaks in a ported design are actually the more effecient parts of the enlcosure. Power drops to 1/4 or even less at those peaks, yet we all know from listening to ported boxes there isn't a huge SPL loss at those frequencies either.

For bass race and music classes it's actually benefitial to have these peaks.. Tapped horns for example have 3 impedance peaks, which really helps with power handling thermally

 

[adulbrich 5,000+ posts]

Physical damping of the box will reduce the impedance spikes. It will also reduce the peaks in the output of the box.. Its been done many times in home audio and in vented boxes I can't recall it EVER making anything louder. When measured usually you just see a flatter overall response with smoother roll off. Subjectively it cuts down on a lot of the higher order distortion as well, sounds cleaner. Can't see it having a purpose in a SPL design.
As you already mentioned the impedance peaks in a ported design are actually the more effecient parts of the enlcosure. Power drops to 1/4 or even less at those peaks, yet we all know from listening to ported boxes there isn't a huge SPL loss at those frequencies either.

For bass race and music classes it's actually benefitial to have these peaks.. Tapped horns for example have 3 impedance peaks, which really helps with power handling thermally

Thanks for the info!

What part of Illinois are you in?

 

[T3mpest 10+ year member]

Thanks for the info!
What part of Illinois are you in?

Clinton Il.. about 45 minutes east of Springfield. I'm in between Bloomington and Decatur.

 

[adulbrich 5,000+ posts]

Clinton Il.. about 45 minutes east of Springfield. I'm in between Bloomington and Decatur.

Awesome, if you're ever coming to Springfield, let me know!

 

[T3mpest 10+ year member]

Awesome, if you're ever coming to Springfield, let me know!

I'll probably be able to make a show in august you were talking about on MAF. I didn't make slam this year so I'm kinda bummed, gotta hit up something this summer still tho.

 

[adulbrich 5,000+ posts]

I'll probably be able to make a show in august you were talking about on MAF. I didn't make slam this year so I'm kinda bummed, gotta hit up something this summer still tho.

Alright, cool

 

[MrFoca]

I remember seeing a dude with 4 10 MA HK subs doing this. Did a 149.9 he tried so hard to hit that 150 mark. I'm not 100% if he gained anything cause they were taped up when he came to the show.

 

[adulbrich 5,000+ posts]

Dang, that would suck to be so close and not get a 150

 

[TaylorFade 10+ year member]

Physical damping of the box will reduce the impedance spikes. It will also reduce the peaks in the output of the box.. Its been done many times in home audio and in vented boxes I can't recall it EVER making anything louder. When measured usually you just see a flatter overall response with smoother roll off. Subjectively it cuts down on a lot of the higher order distortion as well, sounds cleaner. Can't see it having a purpose in a SPL design.
As you already mentioned the impedance peaks in a ported design are actually the more effecient parts of the enlcosure. Power drops to 1/4 or even less at those peaks, yet we all know from listening to ported boxes there isn't a huge SPL loss at those frequencies either.

For bass race and music classes it's actually benefitial to have these peaks.. Tapped horns for example have 3 impedance peaks, which really helps with power handling thermally

Not to be contrary... but I've tested damping in an SPL box.

 

[adulbrich 5,000+ posts]

Not to be contrary... but I've tested damping in an SPL box.

What were the results?

 

[TaylorFade 10+ year member]

What were the results?

It's still in there if that tells you anything.

 

[adulbrich 5,000+ posts]

It's still in there if that tells you anything.

Thanks! I won't be competing, just daily. Would it even matter?

Polyfill or polyurethane foam? If you don't want to say because it's a well kept secret for you competing, I understand. If you can share, please do

 

[TaylorFade 10+ year member]

Thanks! I won't be competing, just daily. Would it even matter?
Polyfill or polyurethane foam? If you don't want to say because it's a well kept secret for you competing, I understand. If you can share, please do

Honestly... any and all of these little SPL tricks and tips used will make zero audibility difference. +1dB is HUGE on the meter, but it's not even noticeable in a daily.

And without a TermLab... you would have no idea whether any of them was helping or hurting anyway. I suppose you could RTA to see of anything altered your response though.

 

[adulbrich 5,000+ posts]

Honestly... any and all of these little SPL tricks and tips used will make zero audibility difference. +1dB is HUGE on the meter, but it's not even noticeable in a daily.
And without a TermLab... you would have no idea whether any of them was helping or hurting anyway. I suppose you could RTA to see of anything altered your response though.

Ok, thanks

 

[TaylorFade 10+ year member]

Also, fwiw... most competitors use foil tape. Not duct tape.

Like so...