Product Review

Paradigm Reference Seismic 12 Subwoofer

August, 2004

Brian Weatherhead




● Inputs: 1x RCA, 1x Balanced XLR
● Drivers: 1 x 12" Active, 2 x 10" Passive

● Amplifier: 1200 Watts RMS (20 Hz 150 Hz @ < 0.1%

● Dimensions: 14-1/4" H x 14-3/4" W x 14-1/4" D

● Weight: 67 Pounds
● MSRP: $1,700 USA

Paradigm Group



I must have a reputation for loving bass. Rightfully so!

For the past few years I have truly enjoyed my "Brand Y" Subwoofers. I have a pair of them. They are in my opinion one of the best subs on the market.

If you read my home theater remodel article, you know that I needed (wanted) a change. Let me say it now, these Seismic subs are a change, and a good one at that (they perform beautifully, but in a small space).

First Impressions

I thought honestly that they had shipped me some HGS-18s by mistake. The boxes for these things were huge. Then when I opened them, i saw this small sub. Yet, it weighs almost 70 pounds. At least it passed the heavier is better test with flying colors.

And did I say small? I could easily stack three of these and still be under the visual load of one "Brand Y". And that is why I wanted to try them out. My A/V room is not that big, and I longed for smaller sub footprints.

So, in went the pair of Seismics, and away we went. I ran some XLR cables from my AVM-20 processor and sat back for a thrill ride.


Did I mention they sent two? Yeah, I know. So, I spent some time hunting around with my SPL meter for a couple of sweet spots. Turns out that just set back from the screen, they sounded the best. Once I found the sweet spot I used a 45 Hz test signal and an SPL meter in my listening position to adjust the phase to coordinate with the "Brand Y" pair already in the room.

The Seismic back panel is well laid out, and simple to use. The auto-on feature works as promised, and I used it the entire time. This is something I really like. They also have a 12c trigger, great for automated environments. What really separated these subs is the use of XLR, offering much better noise rejection over longer distances than single ended RCA. Since subs tend to have runs over 15 feet, XLR can really make a difference.

Phase Alignment, Cutoff Frequency, and Bass Contour (boost at 60 Hz) are also included. I would add that it would be nice to bypass the crossover entirely, such as the case with THX configurations.

Fit & Finish

The look of the unit is svelte yet beefy. The flat sides and gloss top do well to hide the massive driver attached at the bottom. The two side passive radiators are also very prominent. Very much to my liking. The power indicator is a blue LED behind the Paradigm logo on the front.

How they managed to fit one 12" driver and two 10" drivers, along with a powerful amplifier, into this small 14"x14" box astounds me.

The Sound

I hate to throw around some crazy adjectives, but these puppies rock. There was a clear brute force difference between the Seismics and the "Brand Y"s. In fact I really felt like one Seismic was a little stronger than the "Brand Y" pair. If you remember the "Brand Y"s were louder and almost as deep as the venerable Velodyne HGS-18. So putting the Seismic in comparison, it will knock you socks off.

They have a very clean authoritative sound, they never once shut off during my torture test. Where my "Brand Y's bottomed out, the Seismics played through. I was skeptical, as I had heard a few "compact" and "loud" subs, and well they didn't sound very good. Paradigm has really hit the nail on the head, very compact, and yet sonically clean.

As you can see from the in-room response plot (measurement includes the effects of the room, compared to an MLS response that filters out the effects of the room), the Seismic 12 has a very flat response. It's not as flat as the "Brand Y", but the "Brand Y" is a lot bigger, and is designed differently, giving slightly less volume but the flatter response. (If all subwoofers performed the same way, there would be need for only one subwoofer manufacturer.) From 50 Hz to 20 Hz, the Seismic falls 25 dB, while the "Brand Y" falls 13 dB. In listening, the Seismic sounded very well behaved, and provided robust reproduction. When commanded to overdrive itself, the unit refused, instead just playing at its max (a limiter kicks in to prevent clipping, and the lack of a limiter on the "Brand Y" is why they can bottom out).

MAX SPL: 123 dB at 50 Hz , 108 dB at 30 Hz [One Unit]

Max SPL: 126 dB at 50 Hz , 112 dB at 30 Hz  [Two Units]

Addendum: Here are some additional data taken after this review was published, in response to comments on various forums. One "Brand Y" was compared to one Seismic. Phase settings were the same (00 on the Seismic, while the amp for the "Brand Y" does not have a phase setting). The subs were measured in the same position in the room.

  "Brand Y" Seismic
Max SPL at Combination of 20 Hz, 31.5 Hz, and 50 Hz 108 dB 120 dB
THD at 20 Hz and 100 dB 18.3% 100%
THD at 25 Hz and 100 dB 28.3% 52.3%
THD at 31.5 Hz and 100 dB 9.9% 11.9%
THD at 40 Hz and 100 dB 7.2% 8%
THD at 50 Hz and 100 dB 4.2% 3.9%
THD at 80 Hz and 100 dB 2.1% 1.4%

Obviously, the "Brand Y" has much lower distortion than the Seismic in the 20 Hz to 30 Hz range, but is about the same in the 30 Hz to 50 Hz range. The higher distortion produced with low frequency fundamentals in the Seismic will result in more audibility, since 50 Hz and 75 Hz (the second and third ordered harmonics of 25 Hz) are much more audible than 25 Hz. With bass, THD is not necessarily undesirable, since it results in more audible impact which some consumers prefer. With input signals in the 20 Hz to 30 Hz range, the "Brand Y" will be felt more, while the Seismic will be heard more. It is all a matter of preference.

Although the unit comes with a bass boost targeted at 60 Hz, I found that I liked it just fine without engaging this feature.

The subs integrate very well into the entire Studio line from Paradigm. They have the same smooth, yet accurate sound of the Studio Reference line. Did I mention that it has a real 1200 watt amp? Not a "maybe if struck by lightning" kind of amp, but a real work horse.


I have absolutely no complaints whatsoever about the Paradigm Seismic Subwoofer. This is one of the only subs that I have ever tested that didn't pop, hiss, overheat, or throw a tantrum during my testing. It has a nice clean sound that vies for King of the Hill. I bet my neighbors don't understand, but I'm sure you do.

- Brian Weatherhead -

Reference Equipment:

Processor: Anthem AVM-20

Amplifiers: Anthem MCA-20, Anthem MCA-50

DVD: Pioneer F-07

Satellite: Dish HD800

Video: Sony Wega XBR 36" , Runco DTV933

Video Processor: Runco Line tripler.

Main Speakers: Paradigm Studio 100's V3

Copyright 2004 Secrets of Home Theater & High Fidelity

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