Ported subs, being used with sealed?

[generalGOTCHA 10+ year member]

Ok, I was walking the flea market, and this dude had a suburban, selling audio. Anyhow he had some 15's called ("Berlins") and what I noticed was he had two of them in larger boxes ported, and to of them in smaller boxes sealed, and was hitting them with some huge amps I could not identify. Needless to say, it was really loud!

I thought mixxing sealed\ported would be a mistake??? Please correct me.

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[revrider1 5,000+ posts]

Iv never seen that before...

I wouldnt do that though

 

[ThatChevyGuy 5,000+ posts]

sure they weren't MERLON?

Those are pretty common in texas.

 

[chaunb3400 10+ year member]

Loud does not equal sounding good

 

[cshaw 10+ year member]

what did you expect? you where at the flea market lol.

last time i went to a flea market, a guy tried to tell me ported boxes are only for suv's. and sealed is only for trunks..........

 

[ThatChevyGuy 5,000+ posts]

what did you expect? you where at the flea market lol.
last time i went to a flea market, a guy tried to tell me ported boxes are only for suv's. and sealed is only for trunks..........

SAME HERE.

 

[generalGOTCHA 10+ year member]

sure they weren't MERLON?
Those are pretty common in texas.

I never saw the name I could have sworn he told me Berlin, their rated 6000Watts each driver. I dunno I googled around for them, but did not find anything (tired today so...)

 

[revrider1 5,000+ posts]

what did you expect? you where at the flea market lol.
last time i went to a flea market, a guy tried to tell me ported boxes are only for suv's. and sealed is only for trunks..........

//content.invisioncic.com/y282845/emoticons/wow.gif.23d729408e9177caa2a0ed6a2ba6588e.gif//content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif

 

[generalGOTCHA 10+ year member]

what did you expect? you where at the flea market lol.
last time i went to a flea market, a guy tried to tell me ported boxes are only for suv's. and sealed is only for trunks..........

The only thing that made me stop at this guys station out of all the other audio sales people within this large flea market, was his box, and setup in his vehicle. He was Bass'ing out before I even saw the setup, and so I had to look //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

He was selling some cheapy subs, but his subs themselfs were bumpin hard !

Anyhow.. I never seen anyone mix subs, and you guys here on CA.com always said not too LOL..

Whats the reason why now that I am wondering about this; why you dont mix them? I guess I wonder about the audio signals being constructive, and the difference of the sealed being a tighter responce, how does this hurt the output ?

This is how I think of it, but dont yet understand it myself:

Is it because the sealed when changing directions faster than that of the ported driver cause phase cancellations?

E.g Ported driver going outwards while the sealed drivers also going outwards, then since the sealed gets there quicker it's already going inwards while the ported is still going outwards which would cause cancellation?

This is something I would like to understand.

 

[Immacomputer 10+ year member]

The speakers will not move faster in one enclosure or another. They will each play the input signal frequency at the rate of the frequency.

Having two different speakers in different enclosures or having two of the same speakers in different type enclosures will not always hurt output and it will not always help. Each speaker will have a different transfer function with a different phase response and how the two systems will interact will be frequency dependent.

While there might not be a loss in output, the system will not perform at the same level that it would if all the drivers matched and were in the same enclosure type with the same specs.

Sound quality will almost definitely take a hit as far as group delay, transient response, and tonality are concerned. Your average bass head will probably not be able to tell though.

 

[audioholic 5,000+ posts]

Is it because the sealed when changing directions faster than that of the ported driver cause phase cancellations? E.g Ported driver going outwards while the sealed drivers also going outwards, then since the sealed gets there quicker it's already going inwards while the ported is still going outwards which would cause cancellation?

This is something I would like to understand.

That is a common mistake. You need to remember, how a speaker produces a 60hz sound is by the cone making 60 cycles a second. An 80 hz note requires 80 cycles per second. So the 'speed' of each speaker's cone motion is the same, or they wouldn't be playing the same note anymore. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif
Generally the cancellation spoke of when saying not to mix ported and sealed is when you have two different systems playing the same frequency band, but each is displaying a different frequency response (ported will have a peak in output near tuning, sealed will roll off shallower than ported below tuning, etc). When 2 different systems with different responses try to play the same band, they dont reinforce each other properly. Normally 2 drivers playing the same frequencies, in the same enclosure types/sizes/alignments, will reinforce each other uniformly. But with the two unlike systems, at some points in the freq spectrum you will get reinforcement, and in some places you will get cancellation. This leads to erratic over all frequency response of both systems mated together. Erratic response is exactly what you dont want.

So yes, adding more subs, even when different types, sizes, or in different enclosures, will make it over all sound louder to your ear. But if you really sat down and listened critically, you would hear response problems (assuming your ears are trained to recognize the cues). This is also another common mistake or argument people use, that adding more subs obviiously makes it louder so that's beneficial. But few people think about what it does to actual frequency response.

Sorry, I actually tried to keep it short.

 

[na_rsx 10+ year member]

this guy again //content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

 

[helotaxi 5,000+ posts]

The other fun part is the gross difference in group delays between a ported and sealed setup. It may sound loud but it will also sound really muddy.

 

[99grandprixGT 5,000+ posts]

i was lucky enough to get to hear 4 audiobahn eternals 2 sealed and 2 ported. it got loud. but oh my it sounded like ****.

 

[I Like Waffle]

I had a guy come into the store today and buy a small rockford amp (p300.1 i think) like 300rms @ 2 ohms or something, but anyway i asked him what kind and quantity of subs he was gonna run on it, and he says "3 12s and 2 18s" so im like what kind of 12s and 18s are they? and he goes "i got one alpine, one kenwood, and one sony, and da 18s is dem hot blockslider uns" Dude got mad when i tried to tell him to use the 2 matching "blocksliders" instead of 5 mismatched subs or itd sound like ****. Told me his **** was gonna knock harder than anything around hurr //content.invisioncic.com/y282845/emoticons/rolleyes.gif.c1fef805e9d1464d377451cd5bc18bfb.gif