Originally Posted by HDgaming42
I have an Onkyo 805 that does MultiEQ XT.
That's why your results weren't so bad after all. I've seen much worse before EQing in my own room. MultEQ XT is not as refined as XT32 of course but it did an okay job. What is awesome is that you get lots of room gain extending the response of the sub as low as 15 Hz.
just trying to get as flat a response as possible before introducing EQ.
It's already not so bad I'd say
Also your graphs only show one channel (left + sub), presumably at one measurement location. You have to realize that the measurements will be different for every channel and other locations. Typically those are averaged (e.g. by Audyssey) so that it does a pretty good job overall and not for a very limited situation.
I can't say I've really wrapped my head around port tuning TBH. Are you sure they are tuned the same? Their woofers are different sizes, their ports are different sizes, and their frequency responses are different. Both models are tuned to 20Hz? How would I verify this?
Yes, all ported SVS subs are natively tuned to 20 Hz. I'd thought I'd see this in the specs but it doesn't seem to be the case. Anyway, the tuning frequency is the resonant frequency of the column of air in the port, so it's exclusively dependent on its volume and overall dimensions. That's why, on the Plus and Ultra models, you can seal a port to change the tuning frequency.
The port acts a bit like the neck of a beer bottle when you blow in it and it makes a sound. Depending on the level of the beverage -- i.e. the volume inside the "port", you'll get a particular tone. It's the same with the sub port (except the tone is at a much lower frequency). There will be a peak added to the natural frequency response of the sub (which for typical enclosure volumes, starts to roll off below about 40 Hz). When well designed, the peak's width and height will match the roll-off almost perfectly and "square off" the response in the low-end. The caveat is that while a sealed sub has a relatively gentle 12 dB/octave roll-off in the low end, the peaked resonance from the port is twice as steep with a 24 dB/octave roll-off. Thus below the tuning, response falls like a rock, and other phenomena enter in action such that for practical purposes the sub becomes more or less useless.
In that regard, both the PB-1000 and PB-2000 have the same 24 dB/octave roll-off and their ports are sized to provide a 20 Hz resonance. Both subs have a roll-off that begins just above 20 Hz and present otherwise relatively flat response. Thus they have a very similar overall response save for the fact that the PB-2000 is more powerfull. In contrast the SB-2000 has a 12 dB/octave roll-off in the low end; and it already has some DSP boosting to flatten the response in the 20-40 Hz octave (all sealed subs have a native response whose roll-off begins around 40 Hz so when you see a sealed sub with a flat response, there is almost always DSP trickery underneath). DSP filtering will alter the phase characteristics of the sub too, so combined with the port resonance in a ported sub, the behavior will be even less predictable if played together.
edit: on the SVS website I'm reading about how ported subs in small rooms (mine is 16x10x7.5) exhibit strong room gain below 40Hz, and I'm definitely seeing this in my measurements. Am I to assume the sealed subs would measure smoother right out of the gate in a room that size versus the ported?
Yes, you seem to have plenty of room gain! But sealed subs do not offer inherently flatter responses. What it all means is that while a ported sub have a huge output advantage over an otherwise similar sealed subs around their tuning frequency, room gain can help lift the shallow roll-off of a sealed sub to provide similar performances in a room with lots of room gain. Your room sure would be a good fit for a sealed sub. But your PB-2000 already performs extraordinarily well so I don't see the need to replace it unless you'd much prefer a more compact sub.
I cringe thinking I bought the wrong sub, but from most of what I'm reading sealed would have been the way to go in such a small room...
Not at all. I too have a relatively small room -- not as small as yours at about 1680 cu ft but still quite small especially for my setup. I'm using dual PC12-Pluses in that room after upgrading from a single sealed SB12-NSD (pretty much like an SB-2000 but with about 3-4 dB less output). I wouldn't go back, especially since I use the Plus in 16 Hz tuning. The ported subs are able to provide so much more output around 20 Hz it's not even funny. And I don't see any drawback except for size -- sound quality is the same to my ears.
Sure, a sealed sub has its low-end picked up by room gain but so does the ported sub's low end, and it would still probably take me several sealed subs to approach the output of a single of my Plus around 16 Hz.
Originally Posted by HDgaming42
Thanks for providing this. I believe my volume is about 1200 cu feet so our situations are quite similar. Perhaps I'll call SVS and see if they can accommodate some kind of trade-in/up. The Canadian distributor's website does not have the wealth of knowledge offered on the US site--this ported/sealed in a small room has completely taken me by surprise (caveat emptor and all that)...
Nah, SonicBoomAudio didn't offer trade-ups. But since SVS began taking direct orders from Canadians this week, perhaps you can arrange something.
In any case, I'd keep the PB-2000!