Nope, because WinISD does not support those. You'll need some other (more complex) software.
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Sealed speakers VS ported
- Thread starter Mackie
- Start date
I tried to do a similar simulation, not specifically for that speaker driver but more generally for filters (that we apply to sealed cabinets)
Normally I apply a low-shelf filter to my sealed cabinets to elevate the lows - I was curious what impact that will have on all the curves, more from a simulation perspective
So this is what I did:
- I generated a Dirac impulse with REW
- in REW I simulated what happens if I add a min-phase low-shelf filter (80Hz, +10dB, Q=0.71) to the Dirac impulse
- then I exported the original Dirac impulse as a wav file and applied the same low-shelf filter on it using Jriver's PEQ
- imported the resulting file to REW to compare it with the REW simulation
- then I repeated the whole process but using a linear phase filter (CraveEQ VST plugin)
Here is what happened:
1. Frequency response
As you can see they are all the same (the sim in REW, the min phase filter from Jriver and the lin phase filter from CraveEQ)
2. Phase
There is a -45° rotation for the min phase filter and it remained linear with the lin phase filter - as expected
3. Group delay
There is a swing in case of the min phase filter but it remained linear using the lin phase filter
4. Step response
Here we can see the impact of the lin phase filter: pre 0ms we can see the pre-ringing or pre-echo
All the above clearly shows that we can indeed change the frequency response of a sealed cabinet without introducing changes to the GD and Phase curves but with introducing pre-ringing.
Now comes the question: which is more audible? A phase-GD deviation or some pre-ringing?
I will not get into that now...
(Just one remark: the amount of pre-ringing varies with different implementations of linear phase filters. I wanted to use thEQorange for this exercise instead of CraveEQ since it has much lower pre-ringing but unfortunately I could not make it work offline with Jriver)
I am also attaching the REW mdat file for those that are interested
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If anything, the "too slow" feel to the ported loudspeaker's response is simply due to its more extended bass response. The ported enclosure's extra output greatly affects a listener's perception in that regard. Of course, one area where the sealed enclosure excels is that it doesn't produce any noise from port turbulence at high sound pressure levels.
As this is somewhat anecdotal (and I agree this is up for debate), I've not found this 'speed' or 'overhang' perception has any correlation with how deep a system goes, personally. =]
Vergiliusma
Member
It depends on the drivers. Low-mid Q woofs will have a higher cut-off frequency without the port assist that may be deemed unsuitable by the designer. Also, ported speakers will generally require more enclosure volume for given compliance and damping.
Says you. My speakers are about 1.5cf internal volume, on no planet is that a "small" speaker... definitely ported, by the way.
Schollaudio
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I didn't get a chance to read all of the replies so forgive me if this is a duplicate. Bass guitar\PA\Prosound woofers tend to have higher FS and higher BR tunning in the 50hz +- range This puts the tunning at where there is more music\sound. The port operates more and is more directly heard. This also allows more box resonance to escape as can be seen on many measurements here on ASR. This can be a negative in both those ranges. From what I've found, choosing a woofer that works well in a box tuned below 30hz and crossing it over to a midrange below where those spurious internal resonant frequencies escape is a good compromise\improvement.
Is 1.5cf a typo?
I'd honestly put that on the small side of the scale for any speaker/sub handling the bottom end.
Maybe I've been away from a home audio focus for too long....?
Use EqualizerAPO software in a PC and stream from it. I have my CD collection burnt to JRiver and also use Spotify a lot. But any old sources like my CD player and BLURAY and Tuner in receiver aren’t getting EQ-ed as a result. A bit of a pain to have to use a PC and the display it requires. Changes the experience for sure from just using component audio.
I agree....with the cold hard facts at least.....can't say the same for the way they were expressed ...
Sealed subs with enough displacement to reach the lowest frequency, at highest desired SPL...without ANY bottom-end EQ boost......
...is the holy grail, .......given unlimited resources and a willing spouse.
Me? I've got the willing spouse, but alas.....resources only allow this man to have DIY ported subs.
I've compared the same drivers in the ported design below, put in a number of different sub designs, including sealed.
If I could, I'd have a ton of single sealed boxes, where no boost needed, and I end up with no low end roll-off at all, at max desired SPL.
Anything sort of that is a "poor man's" solution
So, back to being poor.
When I boost sealed to match ported low end, and then run both without high-pass filters and at SPL levels below excursion risk...
....well, the slight audible improvement couldn't justify sealed.
I consider low SPL the absolute apples to apples best case for sound quality comparison. Adding high-pass filters to raise safe SLP degrades both, ime about equally.
If all you ever do is listen at low SPL, I can see the case for sealed.
But if you like to crank sometimes, ported simply adds too much SPL and low extension per $ spent, imso.
Last edited:
Vergiliusma
Member
Out of curiosity, what drivers?
BMS 18N862
Last time I checked, not really. It's 2 feet tall and 18" deep. Certainly fairly large...
Okay, if your standard for "large" is this, then sure, it's not that big. But that's the size of a goddamn refrigerator.
@ posvibes, too funny !
to prove I had spousal approval for big speakers in the living room. His post kind set me off I guess.
But I think there was truth in his post that sealed is at least theoretically cleaner; and I do believe slightly audibly cleaner, than ported.
After getting sealed and ported transfer functions to fully match using the same driver, I've made a number of scoped microphone tone bursts / wavelet captures.
So far, the scope captures are only measurement I've found where they differ (after transfer functions are made to fully match).
Point here is, I'm probably overinvested in the sealed vs ported debate, and can take off half loaded lol.
Anyway, I kinda stupidly jumped in about physical size, because small, medium, or large speakers,.... that is clearly a personal judgement.
My apology for questioning your take.
Personally, I tend to put speakers into "size" bins, not so much according to physical size, but according to their measured low end acoustic output.
I think low end acoustic output/extension sets the foundation for the full speaker. And hence its apparent sonic size
No, that frig sized sub is not my standard for large. It is over the top huge, and i only posted it as push-back to @Bach,
to prove I had spousal approval for big speakers in the living room. His post kind set me off I guess.
But I think there was truth in his post that sealed is at least theoretically cleaner; and I do believe slightly audibly cleaner, than ported.
After getting sealed and ported transfer functions to fully match using the same driver, I've made a number of scoped microphone tone bursts / wavelet captures.
So far, the scope captures are only measurement I've found where they differ (after transfer functions are made to fully match).
Point here is, I'm probably overinvested in the sealed vs ported debate, and can take off half loaded lol.
Anyway, I kinda stupidly jumped in about physical size, because small, medium, or large speakers,.... that is clearly a personal judgement.
My apology for questioning your take.
Personally, I tend to put speakers into "size" bins, not so much according to physical size, but according to their measured low end acoustic output.
I think low end acoustic output/extension sets the foundation for the full speaker. And hence its apparent sonic size
Just remember size matters! Go big or go home.@ posvibes, too funny !
No, that frig sized sub is not my standard for large. It is over the top huge, and i only posted it as push-back to @Bach,
to prove I had spousal approval for big speakers in the living room. His post kind set me off I guess.
But I think there was truth in his post that sealed is at least theoretically cleaner; and I do believe slightly audibly cleaner, than ported.
After getting sealed and ported transfer functions to fully match using the same driver, I've made a number of scoped microphone tone bursts / wavelet captures.
So far, the scope captures are only measurement I've found where they differ (after transfer functions are made to fully match).
Point here is, I'm probably overinvested in the sealed vs ported debate, and can take off half loaded lol.
Anyway, I kinda stupidly jumped in about physical size, because small, medium, or large speakers,.... that is clearly a personal judgement.
My apology for questioning your take.
Personally, I tend to put speakers into "size" bins, not so much according to physical size, but according to their measured low end acoustic output.
I think low end acoustic output/extension sets the foundation for the full speaker. And hence its apparent sonic size
Vergiliusma
Member
"There are many paths to ascendancy, some more subtle than others." Steven Erikson
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