OK- It's Been 4 Weeks- PSB Subsonic 6i vs SVS 25-31 PC Plus (1 Viewer)

I wanted to wait and see if my initial impressions held up before writing this...

4 weeks ago I purchased a PSB Subsonic 6i sub to use in my HT system, planning to move the SVS up to my stereo system to augment my Stratus Golds. I made the move, and noticed that I was liking the bass much better from the PSB sub.
It seemed to be more articulate, and 'faster', if that word can be used to describe bass. At the time, I was happy with the extra weight in my stereo system that the SVS provided.

I'll bet that the SVS measures better as far as max SPL's go, though that is not an issue in my smallish(12x13x8)
HT room. And I'm sure that it is also capable of going a few Hz lower overall. But it just doesn't sound as good as the PSB. I wish I could better state what exactly it is that I like about the PSB's sound, but I can't. 'Cleaner' certainly comes to mind, and not the least bit boomy. At the same time, it seems to have more impact.

I guess there is more to a sub than the way it measures- that is certainly true of loudspeakers in general. The PSB has raised my enjoyment level a notch or two, that's for sure.

I was quite surprised at this result; I was able to purchase the PSB at a ridiculously low price, and was planning on selling it when I bought my next SVS. Now I'm keeping the PSB, and plan on trying it out in my 2 channel system next. I'll let you know how it fares.

The PSB Subsonic 6i is a worthy contender in the sub arena. Some of you might want to give it a listen. Perhaps there are some test results out there that bear out my impressions.

PS- Both subs were calibrated to similar levels, and placed in the same area.

Description of Subsonic 6i from PSB's website:

"Extended low-frequency coverage, made possible in part by an oversize rubber surround that permits very long cone excursions—for response within 3dB down to 29Hz and useful output down to 26Hz."

Down 3dB at 29hz??

It seems to me that the lack of truly deep bass sometimes makes music sound tighter?

Here's some graphs:

http://soundandvisionmag.com/assets/...micsubslab.pdf

The PSB did pretty good compared to the others in this group. 94dB at 20hz 10% THD is pretty good.


It's strange that PSB specs the 6i as -10dB at 26hz, yet it seems to perform much better according to TN in that Sound & Vision review.

While bass is bass how subs reproduce bass sound isn't. This is why people should listen to subs before buying them. Subs do have a sonic signature just like speakers. Find the one that sounds pleasing to you.

PBP measures 30-118Hz +-2.5dB. As here have been stated before, if subwoofer is lacking sub 30Hz material, it will sound faster and tighter. That little boom that you heard from your SVS, comes from those lower frequencies, which naturally sound slower and boomier. If you want your SVS to sound similar, you can use BFD to cut sub 30Hz away. With music it can sound better and "faster".

That would be a good experiment! Not that i don't believe you, i probably do. I'm slowly moving toward the "its all about the frequency response" camp, thanks to my own use of the great BFD.

For those that care to look, S&V and the PSB Subsonic 6i...
pdf-included

http://www.soundandvisionmag.com/art...&page_number=9

Ilkka R has a good point; high passing a sub at 30-35 Hz often has the effect of "tightening up" the sound, since low frequencies take longer to decay in the room.

But it could be more than just the differences in extension. If the bass notes are easier to follow on the PSB, it would not surprise me if the PSB/mains exhibit a bit more emphasis in the 60-90 Hz region than does the PC+/mains.

An emphasis (even a mild one) at 60-90 Hz, coupled with a comparative lack of deep extension, can certainly affect the impressions of how "musical" the sub sounds, because it will tend to make the mid/upper harmonics of the bass instruments easier to follow. So the more accurate FR is not always the one preferred by the listener.

Both units are vented and the PSB likely has a higher tune point (just based on the cabinet size, the likely vent length, and the rated extension) so it will almost certainly exhibit larger group delay numbers higher up in the pass band. So you can probably eliminate GD as a factor.

If James ran an accurate FR sweep of both systems (sub/mains) at the listening position, I'd bet we could determine why/where they sound different, and likely explain a listener preference for one sub (or the other) on different source material.

Yup. It's not really about the numbers and graphics. It's all about musically. IMO.

Yup, to hell with accuracy.

Ron

With due respect, accuracy seems not to be a problem here.

With 98% bandwidth uniformity (according to Mr. Nousaine's measurement results) in the music bandwidth, I doubt that more accuracy would help or hurt what the listener is reporting.

Chris, in all honesty, I was on the 'most output wins' side of the fence regarding subs until now.

The PSB just seems to have more 'texture' in my system. I've heard muddy sounding loudspeakers that don't go much below 55Hz, and I've heard others that were tight as a drum an octave lower.

Isn't it possible that PSB simply made a great sub? I mean, really, to impugn its accuracy because it's not the great, all-powerful SVS when Nousaine--a stickler for accurate measurements--pronounced it highly accurate in the S&V review is a bit much. I have no stake in this issue (I don't own a PSB sub, nor have I listened to either the one in question or any SVS subs), but I find the cheerleading for SVS a bit overwhelming at times. I've read reviews and they are considered wonderful by almost all, if not all, the reviewers I've read. That's fine. But they are not the only good sub manufacturer on the planet. I'm not going to get into the "accurate" vs "musical" debate, as others are more qualified to discuss that issue, but I don't think it's beyond the realm of possibility that an SVS sub might not be preferred over another brand, and that the preference for another brand is not based on someone's lack of appreciation for accurate bass.

I don't want to pick just on SVS. A number of other manufacturers of various types of gear, on various forums, have their own cheering section too. And I'm a big fan of my own gear too. But (and this is not SVS--the company--'s fault), unlike most of the cheering I see for other products, the SVS cheerleading section has a bit of a condescending attitude towards other sub manufacturers, IMO.

As an aside, it's interesting to note - almost to a sub - they all exhibit a noticeable drop in THD limited output at 40 Hz. This is more than likely a room resonance occuring at 80 Hz or 120 Hz, acting like a distortion harmonic.

Anyway, I'm glad James likes the PSB; I'm just interested in determining why he might prefer its sound. Listener preference should be explainable with measureable differences between two models.

If (at first) we can't explain a listener preference with objective measurements, then we are measuring the wrong things. I honestly believe there is no mystery or "magic" about loudspeakers or subwoofers. If we can hear a difference, it can be explained with measurements.

Here's a recent quote from a Test & Measurement World article about Harman International and Floyd Toole:


Musical tastes differ, but tests show that listeners respond with the consistency of spectrum analyzers to loudspeaker performance.

*snicker*

That's from a guy peddling woofer in a paper tube...

Andrus,

None of our subwoofers is made of "paper", please get your facts right.

Also, they do not have pedals, they all have motors. No need to pedal them.

Maybe we should worry about all the subwoofers made from sawdust and glue (including SVS's) also known as "MDF"?

By the way, the word you are searching for above is "musicality".

Back to your snickering, by all means.

Ron

*Notes ignorance*

Paper, cardboard, MDF, all a form of wood is it not?

*Notes typical subwoofer discussion pettiness*

*Sighs*

To clarify:

Please understand that slighting SVSubs is the last thing I would do in this case. They make excellent, clean, low freq machinery by any standards.

I would like to throw out a thought FWIW.

I think that subjective impressions of any sub are dependent on a combination of many things. Some of those things we are all familiar with such as, placement, time alignment and calibration.

One thing I've discovered that is contrary to popular belief is that digital recordings DO contain subsonic artifacts.

Having run a system of discrete redirected bass subs and a discrete LFE sub for years, I can say with a high degree of certainty that if a sub is able to play flat, anechoically, to the subsonic region, it will not only reproduce those artifacts, it will work with the room to grossly distort them.

In fact, I just read a post with a graph of a sub from the LP that had been EQ'd to a 'house curve' that steadily rose to 12 dB higher at 20 Hz than at 100 Hz.

It's a big eye opener to see a driver waffle wildly during playback of even a Hi-Rez MC disc, even during dead spots. When I first encountered it, knowing that there was no subsonic content on this particular disc, I flipped on a 20 Hz HP filter and the driver instantly settled down.

What sort of intermod, cross mod, etc., distortion would this scenario create? What would that mean to subjective impression? Are there other non-linear distortions that are readily audible through one sub vs another?

If on the other hand a sub drops off well before 20 Hz, it naturally filters these artifacts, etc., but retains playback of the music content.

It would be interesting if someone devised a test for this sort of thing.

Again, not a chance I would slight an SVSub...but there's no way I think James Edward (and a lot of other folks) are tone deaf, either.

Just a thought that may go to putting a measurement methodology with subjective descriptions.

Thats why you buy it, and that bias should be obvious once you know the person owns the gear. I learned the hard way on this forum not to compare any subwoofer to an Svs as whatever you said was for any other brand was taken as a negative against Svs, even if your only expressing a personal preference.

PC