Ported hitting deep versus Sealed hitting deep?

[efm80 10+ year member]

With a ported box being tuned at anywhere from 30-36hz lets say, why does it sound deeper than a sealed box??? If its tuned like at 32hz doesn't it not play frequncies good below 32hz?? But a sealed plays pretty flat and good along all the frequency levels like 20hz-30hz why does it not hit and sound as deep compared to ported boxes??

eddie

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[dipitydoo 10+ year member]

a ported enclosure will still have good usable output below its tuning frequency before a steep drop in output. With a tuning of 32hz, it still might have decent output somewhere into the 20's. Plus, it is already benefiting from higher output at those frequencies before the quickly diminishing output. Go significantly lower in frequencies and things will change. Most music doesn't go that often into the low 20's, so this is why a tuning frequency in the thirties is common.

 

[tcguy85 10+ year member]

perfect example, my sub in winisd has a -3db point of 28hz. in car it's flat out to 20hz then it starts to drop off pretty fast with a -3db point of about 16hz.

i guess i should mention that my box is tuned at 30hz.

 

[Rashaddd 5,000+ posts]

perfect example, my sub in winisd has a -3db point of 28hz. in car it's flat out to 20hz then it starts to drop off pretty fast with a -3db point of about 16hz.
i guess i should mention that my box is tuned at 30hz.

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thats a matter of specific car acoustics, your car is significantly boosting your low low end if thats really the case, or you're just getting less cabin gain in the middle of the sub range

it certainly isn't a rule that applies to ported boxes in general

 

[tcguy85 10+ year member]

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thats a matter of specific car acoustics, your car is significantly boosting your low low end if thats really the case, or you're just getting less cabin gain in the middle of the sub range

it certainly isn't a rule that applies to ported boxes in general

thats exactly my point. the car itself will do its own thing. sometimes good, sometimes bad.

the OP stated that he thought a ported box tuned at 32hz had zero output below 32hz. and i was disproving that.

 

[nauc 10+ year member]

for reference, heres the in-car prediction of the 12" RE SE in 1 cube sealed vs in 2 cubes tuned to 33hz using BBP

white = sealed

 

[cshaw 10+ year member]

yes, more is to be had or not so due to cabin gain. sealed vs. vented is always the case in "hitting hard" or sound good. you just have to learn the acoustics of your ride to gain what you really want.

 

[helotaxi 5,000+ posts]

It depends on what you consider "deep." Tuning in the mid 30's is going to make the subs really loud in the low 40s and mid to high 30s. That is the freq range that most consider "deep" but when you start getting into the really low stuff, that setup will basically just flutter with no real output. The cone will move. There will be sound. But it won't be anything like the input signal.

 

[kovemaster559 5,000+ posts]

id go sealed if looking for a flat reponce rate thats relatively fast

 

[efm80 10+ year member]

perfect example, my sub in winisd has a -3db point of 28hz. in car it's flat out to 20hz then it starts to drop off pretty fast with a -3db point of about 16hz.
i guess i should mention that my box is tuned at 30hz.

having a hard time understanding this reply?? -3db point?? and "in car it's flat out to 20hz then it starts to drop off pretty fast with a -3db point of about 16hz?

and what kind of car is it?? lastly do you have a sub/infra sonic filter on??

thanks

eddie

 

[tcguy85 10+ year member]

having a hard time understanding this reply?? -3db point?? and "in car it's flat out to 20hz then it starts to drop off pretty fast with a -3db point of about 16hz?
and what kind of car is it?? lastly do you have a sub/infra sonic filter on??

thanks

eddie

it all means the program i designed the box with plotted out a -3db point of 28hz. meaning when it starts to roll off it's -3db point is at 28hz. the program figures this out without taking cabin gain into affect, kinda like the response in an open field with no reflections to boost anything.

in my car using my RTA which plots out the actual response in the car, it's flat out to 20hz. then starts to roll off with the -3db point being at around 16hz. the cabin gain in my car boosts the bottom end very nicely and gives me a pretty nice response down low.

the car is a scion tc (a hatch), and i do not have my sub/infra sonic filter on. i see no reason to use it in my case.

hope that helped.

 

[efm80 10+ year member]

it all means the program i designed the box with plotted out a -3db point of 28hz. meaning when it starts to roll off it's -3db point is at 28hz. the program figures this out without taking cabin gain into affect, kinda like the response in an open field with no reflections to boost anything.
in my car using my RTA which plots out the actual response in the car, it's flat out to 20hz. then starts to roll off with the -3db point being at around 16hz. the cabin gain in my car boosts the bottom end very nicely and gives me a pretty nice response down low.

the car is a scion tc (a hatch), and i do not have my sub/infra sonic filter on. i see no reason to use it in my case.

hope that helped.

definitely helped...couple questions though:

1.) Why do you not have your infrasonic filter on and see no reason for it????

2.)I have a 2008 Honda Accord 4 door sedan. With my ported box tuned at 32hz what kind of results do you think i would see in RTA in my vehicle?? Similar to

yours?

3.) Do you think I need my infrasonic filter on? I have two JL HD750/1's each going to a 12W7. On the specs it says the 12W7 hits as low as 18hz. The infrasonic is set at 30hz on the amp and you cannot vary it! This had me wondering if I set it on would I lose alot of the 20-30hz range. With my setup could I leave it off too or would I not notice a difference with it on because music does not go below 30hz often? I don't want to hurt my subs, but I do not want to kill my 20-30hz range.

Might I add for 3 years in my old setup with 2 12" Infinity Perfects ported at 34hz I had a PPI PCX2200 2 channel amp bridged on them. The amp didn't even have an infrasonic filter and It never seemed to make a difference or hurt my subs without one. just a thought...

thanks!

eddie

 

[tcguy85 10+ year member]

definitely helped...couple questions though:1.) Why do you not have your infrasonic filter on and see no reason for it????

2.)I have a 2008 Honda Accord 4 door sedan. With my ported box tuned at 32hz what kind of results do you think i would see in RTA in my vehicle?? Similar to

yours?

3.) Do you think I need my infrasonic filter on? I have two JL HD750/1's each going to a 12W7. On the specs it says the 12W7 hits as low as 18hz. The infrasonic is set at 30hz on the amp and you cannot vary it! This had me wondering if I set it on would I lose alot of the 20-30hz range. With my setup could I leave it off too or would I not notice a difference with it on because music does not go below 30hz often? I don't want to hurt my subs, but I do not want to kill my 20-30hz range.

Might I add for 3 years in my old setup with 2 12" Infinity Perfects ported at 34hz I had a PPI PCX2200 2 channel amp bridged on them. The amp didn't even have an infrasonic filter and It never seemed to make a difference or hurt my subs without one. just a thought...

thanks!

eddie

you said it right there. there isn't much musical content below 30hz.

i listen to rock & metal, not rap. but even with rap there still isn't much below 30. i have watched my sub carefully and the thing barely moves so i am not worried one bit about it being damaged from low end bass. its a very efficient sub and its tuned low so output is great with little excursion.

as for your car having the same cabins gains, that i cannot say. my car is a hatch, and yours a sedan so i really don't know. if you know somebody or a shop with an rta you can easily find out.

 

[efm80 10+ year member]

right on bro, so to my question #3 should I use my infrasonic or not. I listen to rock, trance, and a little rap. want those low frequencies, but don't want to hurt my subs. Although with them being 12w7 and hitting low and having high excursion capabilities you think I can set it OFF??

also, with RTA's results with your car showing that even 10hz below your tuned frequncy of 30hz its stll playing flat!!!??? thats crazy. So a car's acoustics allows the ported box to defy its own physics and play flatter much lower than your supposed winisd showed??

lastly would anyone on here be able to chime in for my Question #2 about my car results in RTA or at least a similar 4 door sedan??

thanks

eddie

 

[tcguy85 10+ year member]

right on bro, so to my question #3 should I use my infrasonic or not. I listen to rock, trance, and a little rap. want those low frequencies, but don't want to hurt my subs. Although with them being 12w7 and hitting low and having high excursion capabilities you think I can set it OFF??
also, with RTA's results with your car showing that even 10hz below your tuned frequncy of 30hz its stll playing flat!!!??? thats crazy. So a car's acoustics allows the ported box to defy its own physics and play flatter much lower than your supposed winisd showed??

lastly would anyone on here be able to chime in for my Question #2 about my car results in RTA or at least a similar 4 door sedan??

thanks

eddie

you could try it with it turned off. you should be fine if you're tuned low enough and listen to real music, not straight up test tones.

yea it's nice that it can play flat down to 20hz. i wouldn't call it defying physics. its simply the reflections in the car exaggerating the low end, thats all.

same thing happens in a room in a house. the walls, ceiling and floor will all create spikes and possibly dips at certain points in the spectrum. in my HT i have a pretty big spike at 50hz but i could lessen that spike if i moved my front speakers out from my walls instead of having them right up again them. but right now i don't have a sub so i am leaving it alone.