# Dual PSA S3600i vs. dual SVS PB13-Ultras – Finding bass nirvana and lessons learned



## zorax2 (Apr 7, 2014)

I’ve had the good fortune of having a pair of dual SVS PB13-Ultras (with the BASH amps) in my 1,700 (12’ x 16’ x 9’ H) cubic foot room. I’ve run them extensively in 15 Hz, 20 Hz and sealed modes seeking bass bliss. The PB13 Ultras sound great, no denying that – however, I never quite found what I was looking for in a room much, much smaller than most rooms that run with PB13-Ultras in a dual configuration. I’d read so many posts on the various forums describing how dual ultras shook the walls, produced incredible slam, knocked things off shelves in other rooms, completely pressurized the room, etc. Why wasn’t this happening for me?

PROBLEM SOLVED! – Dual Power Sound Audio PSA S3600i subs

WOW! I finally found what I was looking for and more. These subs truly rock my room. I finally felt the tactile impact I was looking for with great sound, full room pressurization and a shelf even fell off a cabinet in an adjoining room! 

I was very fortunate a couple of true “bassheads” to my home to demo the S3600is and compare them with my dual Ultras. These guys have had exposure to some of the best commercial and DIY subs available and have built some awesome subs of their own including the THT, Gjallahorn, Othorn 21”.

When they arrived, I had the room setup with dual PSA S3600is in a nearfield configuration next to my theater chairs and one of the PB13-Ultras in the front corner of the room running in sealed mode (not it’s optimum mode but I was trying to see if it would blend in as best as possible). With the master volume at -12 dB and the subwoofers with +10 dB gain (-2 dB from reference level bass), we put the “Edge of Tomorrow” Blu-Ray in and hit play. The opening sequence starts with its wave of 30 Hz, 20 Hz and 10 Hz tones with room and sub-wrecking bass to start. Within seconds, we hit the mute button as the PB13-Ultra had reached its limits and we knew it had no chance to hang with the dual S3600is.

We immediately disconnected the PB13-Ultra knowing that it would be the limiting factor to the whole system, and as part of the system, would never allow us to explore the potential of the S3600is. I asked the question “Why didn’t my dual PB13-Ultras give me the performance I wanted in this room when so many people suggested they would be overkill for such a small room?” Our discussion led us to believe that being on a concrete floor on a lower level took away much of the performance from the Ultras. One of the guys mentioned another person who loved the Ultras on his main floor as they really rocked the house. Later, this same person had to move the system to the lower level on a concrete floor, and was completely disappointed with their performance in the new space. One of the lessons I learned was that with a theater on a concrete floor rather than on a wood floor or riser setup, you will need much more subwoofer capability to give the impact and slam most people here on the forums desire. The other lesson I learned was that there is no substitute for raw displacement. There was simply no way a single 13.5” PB13-Ultra driver is going to keep up with the dual 18” drivers found in each S3600i sub. What was also interesting was that the form factor of the subs was nearly identical in terms of size and footprint which made it very easy to me for sub placement.

Now that the PB13-Ultra was “knocked out”, we decided to keep pushing to see how far the S3600s would go. We went back to Edge of Tomorrow and kept cranking it up a couple dB at a time. The S3600s weren’t even breaking a sweat when I think we were at Reference +4 dB “hot” on the bass and we tripped the circuit breaker. I found out that a 15-amp circuit does not support a single light bulb, a projector and two S3600s.

I found an extension cord and another circuit for one of the S3600s, put the projector and the other S3600l on another circuit and the rest of my audio gear on a third circuit and we got back to testing the 3600s. I don’t recall how far we pushed it with the other movies we tried but the sound and room pressurization were incredible for everything we played. At no time did it even seem we were close to the limits of these subs in my room. We put our hands next to the cones of the subwoofers and didn’t feel things heating up and found the amp starting to warm up but not overly hot. I think we had a long way to go in pushing them with plenty of headroom to play with if I so choose.

We then decided to dive into some music. We started off with the Eagle’s Farewell – Live From Melbourne on Blu-Ray with Hotel California. For this, we dialed the bass way, way back to a level suitable for music. The S3600s kept up very nicely with the music and sounded great. We then moved onto some solid bass demo music. Now it was time to seriously crank up the bass. It was absolutely crazy as the room began to shake, the pressurization further increased, the chest slam was coming hard and we began to laugh as the image from my projector started to bounce around and go in and out of focus – hilarious! While my friends had experienced this (and more) previously, I had never experienced such crazy bass. We kept pumping up the volume to master level 0 dB with the subs gain at +10 dB. The subs still weren’t breaking a sweat and my fellow bassheads kept coaxing me on with a thumbs up to turn up the volume. We kept going a to master level 0 dB, sub gain +10 dB and trims +4 dB when my Denon AVR-X4100 went into protective mode and shut down as I was probably driving my other 5 main, center and surround speakers too hard. After already tripping the breakers earlier, we started laughing as we still hadn’t found the limits of the S3600s. Unbelievable!

By this time, we had been at it nearly 3 hours and we had to finish. I think we all left feeling that PSA had put together a tremendous sub for the money, that sounded great and was a wonderful fit for my room. I wanted to make sure I wasn’t going to ever have further sub envy and we discussed a number of other competitive subs and agreed that short of a much larger commercial or DIY sub, the S3600 was an incredible value and tough to beat. The dual 3600s are about 20% less expensive than a set of new dual PB13-Ultras and simply left them in the dust performance wise. Tom Vodhanel from Power Sound Audio was wonderful in answering the many questions I had prior to purchasing the subs and even managed to ship the subs the same day I ordered them. Great customer service! Top this all off with a 30-day trial period and a 5-year warranty – that’s hard to beat.

My hunt for subs is now over – the dual S3600i subs are incredible and give me everything I could ask for. I am absolutely thrilled with them and highly recommend them!


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## theJman (Mar 3, 2012)

I'm glad your journey ended so well! I know you were after something the PB's weren't able to provide, but it sure sounds like you found it now. :hsd:


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## Cal68 (Jun 27, 2016)

I just replaced one of my SVS PB-13 Ultra subwoofers with a PSA V3600i. I'm still breaking in the PSA sub but the difference between the before and now seems to be huge. But my family is awestruck at the size of the PSA sub. The SVS was a biggie, but the PSA is "huge"! I do hope that I can get it to play well with the remaining PB-13 Ultra!

Cal68


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## craigsub (Sep 9, 2006)

Yes, it has been 6 months since anyone commented on this thread, but it actually brings home an excellent point on subwoofers.

A single PB-13 Ultra would deliver about 2-4 dB higher output at 20 Hz than would the S-3600i in a CEA-2010 burst test. 

A typical post would be, if one just looked at the CEA-2010 data, is that the Ultra is the "superior subwoofer, it is 2-4 dB better than the S-3600i ... "

In the mean time, in a real world listening session, the guy who already owned the Ultras said this: """The dual 3600s are about 20% less expensive than a set of new dual PB13-Ultras and simply left them in the dust performance wise."""

Listening to subwoofers is important. 

Relying on people to tell one that a subwoofer is superior based on 2-4 dB in output at 20 Hz is happening all too often, and people are missing out on some tremendous products because of this.


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## Tonto (Jun 30, 2007)

Hey, good to hear from you Craig! Last thing I remember is you were setting up some LaScalas in a room. How did they ever turn out. Those really are impressive speakers.


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## craigsub (Sep 9, 2006)

Tonto - Good to see you, too. The last year has been quite the adventure!

We have a big old farmhouse here, and now have 5 listening rooms. The LaScala II's are in the family room with a Hsu VTF-3 Mark V and are sounding fantastic!

The other rooms are anchored around 1. Legacy Signature SE's or Axiom LFR-1100 ... 2. Axiom M-100's ... 3. Martin Logan Electrostats and 4. Axiom M50's


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## theJman (Mar 3, 2012)

Tonto said:


> Hey, good to hear from you Craig!


Yes indeed! :T


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## craigsub (Sep 9, 2006)

theJman said:


> Yes indeed! :T


Jim - You are a moderator here? Now I will never get away with anything. 

This thread inspired me to order a new V3601. We have an Axiom EP800 here now, and it looks like 2017 will see maybe 4 different $2000-$2500 subwoofer or subwoofer packages tested here. 

The original 18's in Powersound subs was really close to the 18 we had in the old Chase Home Theater. I don't know if the new 18's are also Eminence drivers on a new platform (the old 18 was as powerful an 18 as Eminence had - about a 21mm X-Mech one way) or a driver from a new company. It appears PSA is expecting 2-3 dB more output from the new driver, so dual 18's with sufficient amp power should make for one potent package.

Based on your take on the Hsu ULS-15 Mark II, maybe a pair of those will be added to the mix later this year.


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