Ported Subs to Sealed Subs...

AVForums

Help Support AVForums:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Jason Willemse

AVForums Super Veteran
*
Joined
Oct 16, 2016
Messages
1,272
Reaction score
564
Location
Johannesburg
Yesterday I received the two SVS SB12-NSD subs from Drifter down in the fair Cape. They arrived in the pristine condition they were promised to be, so doing business with Drifter I can certainly recommend.

The development that led to this purchase is interesting in that the seller was moving from using two sealed subs to two ported ones, whilst mine was going in the opposite direction from two ported units to four sealed. We got into some good discussion between the differences, pros and cons of either application, with us generally in agreement.

Now, having received the two, the time came to put it to the test.

The room is around 7x6m with viewing wall being the longer of the two. The room had a number of different systems and configurations over the years, so I?m quite familiar with its reflection characteristics and best suited positions for speakers and subs. The arrangement is in a 7.1.4 ATMOS config.

Now the four subs are arranged in two stacks, two subs on each outer side of the FL and FR speakers, like so:

39f46c0d2eaaab8fa5d2cca870161130.jpg


Each stack is fed by the two independent sub channels of the AVR, split at the subs into the two separate LFE inputs. Phase is set to zero on both,  with the crossovers set at their highest allowing the AVR to do the math. The gain settings of each of the four subwoofers was done independently using the AVR?s own sub level matching tool upon set up. Each was matched so that the combined efforts of each stack was closely matched to the other and within the limits of Audyssey?s recommended dB?s for calibration.

Audyssey calibration run, some manual tweaks from Large to Small speakers and the associated crossover points, and we were ready.

The first test was done with music, using my collection of reference tracks that I am most familiar with. I had previously disabled the two ported subwoofers completely for 2-channel audio due to simply not liking the sound. The bass would be really nice and low, but somewhere up around the higher sub-bass frequencies it didn?t tickle the way I wanted it to. There was always a sense of there being subwoofer presence in the room that wasn?t seamlessly integrated with the mains. Could be room, could be many things, but I had tried all I could and gave it up.

Testing with music continued and I was very impressed. Completely seamless, tight room filling bass without overpowering the stage and dynamics of the two PL300?s. The bass was also well balanced throughout the room with no noticeable hotspots. I played a little with the crossover settings on the AVR a little more, and settled on a a 90hz crossover to the sub, and 60hz for the mains. So for music, tick the box ?great improvement?!

Next up, I lined up some of my favorite movie and series scenes in ATMOS, and settled in for some further testing. First up, the all familiar Dolby ATMOS test disc track one ?Amaze?. ?DU-dum, DU-dum?... the heartbeat opening audio sequence of the disc hit deep and clear, and rather differently to what I was previously accustomed to. The lower end (bum-bass) of the sub-bass spectrum was similar to before, giving the couch cushions and armrests the deep vibrations I was used to. It was the impact of the bass that felt much more different. It was a hard and fast attack, startling in a way. I adjusted the mains to 80hz from 60, allowing some extra juice to flow from the subs and sounded even better.

Now I must note that a was previously using two PB1000?s, not the bigger pair of 2000?s that Drifter has now installed. If you saw these next to each other, you would note a significant size difference.

When using the PB1000?s I would notice a turbulence at reference level in this same opening sequence - a sort of flutter in the middle of each heartbeat as the first part of of each double beat lead into the next. The grip was perhaps not as firm, maybe stretching the subs a little too far for the room.

Into the sequence of clouds rolling overhead and the rumble of thunder rolls across the plains, the four SB12?s remained composed, delivering bass deeper than what my expectations were for that particular scene.

My son and his friend joined in for some opinions for their games:

87b19f57f1f37cbb924467ca3e86098c.jpg


Phase alignment between the two subwoofers of each stack is still bothering me. I?m going to need some help in this regard using REW and the umik-1, as the AVR has no possible way of doing this other than sorting things out between the two stacks. The only way to do this properly is to optimize each stack separately, then optimize the combination of the two.

I?m looking forward to the weekend to do some more fiddling and trying to get to better grips with REW... volunteers welcome!!!! [emoji51]

Thrilled with the results so far though. Impressed with SVS once again.

cc5011b13e79fefad4b211bfa02bbc42.jpg











Sent from my iPhone using Tapatalk
 

Latest posts

Top