Ported enclosure sounds "funny"

[Dred 10+ year member]

I build a new enclosure of 2.5 cu (a.d.) tuned to +/- 28 hz.

Slot ported vent, 2*15 inch and 29 inch long.

So far everything looks okay but ...

When playing my favorite tunes the sub sounds like its in an "undamped" enclosure.

Experimenting with the foam to damp the enclosure didn't got me anywhere.

it's missing low-end like my old sealed delivered.

Am i looking for something that just isn't there?

Or did something went wrong ... ? //content.invisioncic.com/y282845/emoticons/uhoh.gif.c07307dd22ee7e63e22fc8e9c614d1fd.gif

thanks for the reply in advance

Dred

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[stones 10+ year member]

You forgot to mention what kind of sub.

 

[Dred 10+ year member]

Sorry ...

Its a 15" brandless sub since there's no name on it.

Specs:

Z-Nominal Impedance in Ohms : 4

Fs=Free Air Resonance Frequency in Hz : 28.6

Qts=Total Q Factor of Driver : 0.52

Vas=Equivalent Acoustic Volume in Cubic Feet : 5.8

Xmax=Peak Linear Displacement on Cone in Inches : 0.15

Ref=Driver's SPL 1W at 1m in dB : 90.3

Dred

 

[SPL140.2 5,000+ posts]

maybe port noise?? air leaks??

 

[audiolife 5,000+ posts]

when you say its missing do you mean notes run together or like the music is below tuning freq?

 

[squeak9798 5,000+ posts]

Sorry ...Its a 15" brandless sub since there's no name on it.

Specs:

Z-Nominal Impedance in Ohms : 4

Fs=Free Air Resonance Frequency in Hz : 28.6

Qts=Total Q Factor of Driver : 0.52

Vas=Equivalent Acoustic Volume in Cubic Feet : 5.8

Xmax=Peak Linear Displacement on Cone in Inches : 0.15

Ref=Driver's SPL 1W at 1m in dB : 90.3

Dred

Looks like a sealed box woofer to me....which would explain why you are having such problems with it ported. High Q, low Fs and EBP likely in the 50-60 range (though you didn't list Qes). That's textbook sealed enclosure right there. Only thing going against it (sealed box wise) is the anemic Xmax figure.

 

[Sachmo12345 10+ year member]

maybe your sub just sucks

 

[Dred 10+ year member]

I'm sure it isn't port noise/airleaks.

Some songs are missing notes but only real low ones

it plays "real instrument music" really nice though.

I know its not the ideal sub, but the Xmax figure made me deside to try it ...

have to try my first ported enclosure with something

Dred

 

[Dred 10+ year member]

Tommorow i'm gonna try it isobaric,

maybe the enclosure is to small like Jmac says.

thnx for the reply's.

Keep you posted.

grtz.

Dred

 

[60ndown 10+ year member]

infinite baffle?

 

[JimJ 5,000+ posts]

Tommorow i'm gonna try it isobaric,

I'm not really sure what an isobaric configuration is going to give you, other than higher power handling and more linear travel/less distortion...also, why aren't you using the second sub already? //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

Do you mean inverting, not isobaric?

 

[Dred 10+ year member]

Just thinking out loud something like this:

 

[JimJ 5,000+ posts]

Well, you're correct...that's a classic clamshell isobaric setup.

Still not sure how you'd think it would solve your problems...you'd still be looking at two drivers that won't do well in a ported enclosure. Only now it could take twice the power and have less distortion due to cone excursion.

 

[SSS 18734 5,000+ posts]

maybe your sub just sucks

that was uncalled for. The box matters more than the sub you n00b

 

[Dred 10+ year member]

well i was thinking of it like this:

a classic clamshell isobaric works well in half the size enclosure of 1 sub.

its all an experiment, i was very happy with the sealed setup but wanted to try something different, something new.

Dred