Robert Archer, Senior Editor, CE Pro Bob is an audio enthusiast who has written
about consumer electronics for various publications within Massachusetts before
joining the staff of CE Pro in 2000. Bob is THX Level I certified, and he's also
taken classes from the Imaging Science Foundation (ISF) and Home Acoustics
Alliance (HAA). In addition, he's studied guitar and music theory at Sarrin
Music Studios in Wakefield, Mass.
PS-88 Review by Jim Wilson AVS Forum.
Click Here for Full Review
The subject of this review is the Outdoor Speaker Depot (OSD) PS-88. The PS-88 is an acoustic suspension subwoofer that measures just 10.5"Hx11.5"Wx10"D and weighs a mere 17 pounds. In other words, it's tiny.
The PS-88 has an 8" side-firing driver with an 8" passive radiator (PR), which is also side-firing. The amp is rated at 180 watts RMS with no peak wattage listed. The quoted frequency response is 25Hz-160Hz. There is a 2 year warranty.
OSD is an Internet Direct company, so as their name implies they sell directly to the public. The review unit was supplied to me by the manufacturer, so I didn't utilize the standard distribution channel. You can technically purchase them from other places, like Amazon, but the order is fulfilled directly by OSD themselves.
The review unit came double boxed. The inner box -- the one that contained the sub -- was placed inside a regular shipping box, not one that was custom sized for the PS-88. The shipping box was packed with air filled plastic bladders on all sides, so the inner box was well protected. The PS-88's box had soft foam blocks that encompassed the entire top and bottom of the sub, which was wrapped inside a cloth bag. The packing was more then adequate.
There was no manual included with the review unit because it was still being revised. OSD did email me a PDF version within a day or two of when I received the sub. Beyond the power cord there were no other accessories included.
I found the documentation was pretty good for a budget subwoofer. The grammar and punctuation could perhaps use a little touch-up, but it rates above average for content and completeness.
The cabinet is solid and well made - the ubiquitous "knuckle rap test" returns very little echo. I was especially impressed with the paint job. It's piano (high gloss) black lacquer, with a smooth and even finish. One of the few complaints I had with the OSD PS-10 subwoofer I reviewed a few months ago was that it looked far too bland and generic. That's certainly not the case with the PS-88; OSD has obviously spent a considerable amount of time trying to make their new subwoofer look better. And they succeeded; this unit does not look plain in any sense of the word.
The only feet supplied are rubber, and measure approximately 1 inch. The cabinet is constructed from .7" MDF. Just about all the amp screws needed a .25" turn to tighten them. There are no visible screws for the driver or passive radiator - OSD has covered them with an outer plastic ring. This lends itself to a nice finished look, almost inviting you to remove the grills. The grill frames are made from a plastic material that's about .5" thick, and they're quite sturdy. They attach very securely to the cabinet using large plastic pins. OSD uses a nice cloth material that is adhered perfectly to the grill frame. There's obvious attention to detail everywhere, and the grill is no exception.
Lining the front, top and bottom walls inside the cabinet are sheets of 1.5" damping material. The driver is a very impressive looking thing for it's size. It has a massive foam surround, equaling roughly 50% of it's diameter. The cone is paper based, but the dust cap seems to be made of some type of rigid plastic. It has a 42 ounce magnet, which is pretty large for such a small driver. There's a bump out on the back of the magnet to allow additional voice coil travel, but even with that I did get it to bottom out on occasion. The driver is constructed using what appears to be a stamped steel basket with some type of rubberized coated. The PR is equally impressive; it too has a huge foam surround, although not quite the size of the primary drivers. The cone on the PR is flat and very stiff.
The amplifier appears to be a quality piece. The silkscreening is very clear and legible. The dials move with a nice smooth action, and the switches have a positive solid feel to them. The LED turns red when the sub is in standby mode and switches to green when it's on. The auto-on function worked perfectly. There are dials to adjust the gain (volume), crossover and phase. Adjustable phase is rare on such a small, budget oriented subwoofer. The crossover dial is worthy of particular mention; it shows, in very clear detail, exactly what you have it set for. Far too many manufacturers think you should guess what this setting is, but the PS-88 leaves nothing to the imagination.
The amp itself seems very well designed. The PCB looks properly engineered and nicely constructed. There was nothing about it's appearance -- inside or out -- that said "budget" subwoofer.
There's both left and right low level and high (speaker) level inputs, but only high level outputs. The high level inputs are the less than high end push style, not the more substantial binding posts. The left and right low level inputs don't have the "summing" functionality, meaning there's no 3dB boost if you use them both at the same time. Because of that when using the PS-88 for home theater you connect it using only the left input.
There's a unique switch on the amp labeled SUB-LFE. In essence, this gives you the ability to disable the subwoofers crossover and use your AVR instead. That means you can use the PS-88 for HT or music, and still have full control over the crossover frequency. I found this feature to be of dubious benefit though. When set for LFE the output dropped noticeably compared to the SUB setting, which the PS-88 can ill afford. Because of that I left it in SUB and set the crossover dial to it's maximum and used my AVR to make the appropriate adjustments.
My living room is 13x17x8 (1768 CF), so it's not terribly large. The main seating position is approximately 11 feet from the subwoofer. All testing was done after the unit had been broken in for at least 15 hours.
One of the first things I noticed is how "hot" I had to run the PS-88; the gain knob needed to be set at the 3:00 o'clock position in order to achieve an appropriate output level. Additionally, I had to boost the subwoofer output in my AVR by 3dB from what I normally do, while lowering the other channels 1dB. One of the unfortunate side effects of doing that is you generally run out of head room (ability to play the subwoofer loud) because the amp has very little in reserve. However, I didn't find that to be the case; while the PS-88 did bottom out when played loud on very deep bass passages it took a lot more volume then I had anticipated. Frankly I found the PS-88 was able to play at a higher volume then it's size, amp wattage and driver size would infer.
Overall I'd say the quality of sound was very good. The PS-88 had surprising clarity given it's budget-oriented heritage, but it won't vibrate any of your pictures from the wall. There was a pleasing mid-bass punch, but not a tremendous amount of outright depth. Given it's physical size and 8" driver that's not a terribly shocking outcome though. When it was brand new the sound was somewhat thin and weak, but it did break in rather quickly. By 15 hours or so the sound had changed dramatically.
Because of it's size and driver compliment the PS-88 is a bit more sensitive to placement then perhaps other subs would be. I had the most success with 2 different orientations;
diagonal corner placement, where each side was within a foot of it's respective wall
the driver facing out towards the listening position with the passive radiator about a foot from the rear wall
I run each test scene twice; once while seated in my normal listening position, and then a second time while sitting on the floor a few feet from the subwoofer. This allows me to hear it as I normally would, yet still affords me the opportunity to determine if it's straining even the slightest bit. Both tests are run at the same volume level.
Like most people I have specific DVD's and particular scenes I use when testing subwoofers. A few of my favorites are Lord of the Rings: Fellowship of the Ring, Collateral, Avatar and the quintessential ULF (ultra low frequency) torture test; War of the Worlds. I've also included another rather difficult test scene from the movie 10,000 BC. Each individual test is listed in the format of Movie: Scene.
Lord of the Rings: Bridge of Khazad Doom - There is an ultra low frequency rumble in portions of this scene, as well as significant amounts of impact generated by numerous structures crumbling. For a subwoofer to handle all of that properly it needs to be precise and capable of reaching very deep, otherwise a lot of it comes across as nothing more than annoying resonance. Except for the deepest notes the PS-88 did well.
The individual low frequency effects were clearly defined and each maintained their unique characteristics, but the total was not quite the sum of the parts. It wasn't how everything blended -- because that part was fine -- it was because a bit of depth was missing. I wasn't necessarily underwhelmed by what I heard, just not overwhelmed.
My favorite part of this scene to play around with is the Balrog's roar. There's an instance when you see it for the first time that I just love to crank way up. He jumps out of a cavern and lands right behind the Fellowship with a thud, and then lets out a fire-breathing roar. I enjoy seeing how loud I can play that part, because when the volume goes up it just sounds cool. The PS-88 did very well handling the volume. The huge impact created when the Balrog's feet hit the ground as he chases after the Fellowship lacked the chest thump I'm more accustomed to, but it was still pretty good considering.
Collateral: Club Fever - This disc has the option of using DTS or DD for audio, but I only test with DTS now. In general I've found DTS encoding has a bit of additional low bass and an overall greater depth to the soundtrack, so I've decided to use that exclusively for testing.
Although this scene doesn't contain a tremendous amount of LFE information it does have a driving musical soundtrack and over-emphasized gun sounds. The music portion I've found can cause trouble for a subwoofer because it does tend to drown out the voice track in certain spots, especially if it lacks clarity and speed. Because of that articulation is crucial. The PS-88 pretty much aced this one.
The club music never came close to drowning out the voices. The balance between the various elements was pretty much spot on. The gunfire came across a bit muted though, with less of an emphasis then I've heard in the past.
Avatar: Assault on Home Tree - For those familiar with the movie this scene has low frequencies, ultra low frequencies, explosions, gunfire, voices and enough other things going on to provide a good test of virtually every component in your system. The PS-88 comported itself well for the most part.
As the gunships approach Home Tree you can almost feel the underlying intensity. The roar of their engines, the sound of the rockets being launched, the impact of each explosion, the crackling of the massive roots as the tree begins to list, and all the way to the point where it's toppled and crashes into the ground the low frequency was satisfactory.
This scene has a good range of frequencies, and I often use it to determine how deep a sub can go. Because there is a notable amount of non-LFE material during this part I can always tell how strong a sub is because of the contrasting sounds. All the nuances and detail was plainly evident, but the sense of impact wasn't fully rendered.
War of the Worlds: The Machine Emerges - The archetype... perhaps the most recognized subwoofer test scene of all time comes from a movie that's about 7 years old. The depth and volume of bass that occurs during a several minute span is simply amazing. If you want to see what your sub is capable of this scene can certainly be used as a barometer. With subterranean vibrations, exploding pavement and collapsing buildings you have ultra low, low and mid-bass frequencies pouring out of your subwoofer. One of the most punishing combinations there is, and an excellent way to really push something to the brink. As in the case of Collateral, the DTS audio track is used for this scene. The PS-88 did better here then I thought it would.
This scene -- along with Lightning Strikes and At The Window -- are a chore for any subwoofer, let alone such a diminutive one as the PS-88. I hesitated to even include this scene because I was reluctant to risk damaging the review unit. I figured since I already had it I might as well run it through the gamut, and I'm glad I did too because the PS-88 fared better then I assumed it would.
No, it wasn't able to create a true sensation of the earth moving below my feet. Since there isn't anyone who is going to buy a tiny sub like this with the idea that it can, I don't view that as a problem. But it did surprisingly well, even if I did hear it bottom out a few times. This was one of the few instances where the PS-88's ability to play loud worked against it, because you could over power the driver.
10,000 BC: Mammoth Hunt - During this scene there's either ultra low bass or mid-bass, with very little in between it seems. However, I've found this to be a good way of determining how a sub performs with nuances while being pushed hard. If it's struggling to hit the very low notes then the mid-bass suffers, and will come across as a jumbled mess (lacking in detail). If it can hit the low notes, but isn't articulate, then it tends to sound "thick" or "heavy", losing most of it's distinction. The PS-88's performance on this scene was similar to War of the Worlds; clear, but not quite deep enough to provide the full effect.
In the prelude leading up to the stampede the mammoths are simply milling about, but each earth-rattling thud from their massive feet is supposed to be felt as much as heard. When the stampede begins you then have dozens of rampaging mammoths running to escape. In order for this scene to work properly your subwoofer must be able to produce a tangible sensation of the ground shaking all around you. This was the sole instance during my time with the PS-88 that I felt something was actually lacking. If I cranked the volume up to the point where the driver bottomed out and then backed it off just slightly the sensation was better, but even then it still wasn't quite engaging. I heard the thuds, but didn't feel them.
After all the testing was finished I checked the amp for heat output and found it was nothing more then barely warm. It seemed no matter how hard I pushed the PS-88 the amp was simply not fazed a bit.
I use a combination of lossy and lossless material -- MP3's and CD's -- to see how musical a subwoofer is, and in both instances the PS-88 did well.
I wouldn't go quite as far as saying this is a musical sub, but there was a noteworthy amount of detail. The individual instruments, like kick drums and the bass guitar, were distinguished and properly balanced. On some CD's the PS-88 displayed less articulation and clarity then on others, which means it requires good source material. About the only true negative I found with music was there wasn't quite enough deep bass to project the true essence of certain songs.
In the past OSD's support has been very good, and it's still that way now. I get the sense it's more of a family atmosphere then a corporate one. There's not a lot of the rigid structure you often encounter. With OSD it's more congenial instead. These people are a pleasure to work with.
OSD has an uncommon little subwoofer on their hands, and I do mean little (alright, tiny). It's not physically able to produce deep bass, but it certainly fights above it's weight class (OSD sells the PS-12 if you want deeper bass, so they have you covered either way). The beautiful paint job and minuscule proportions give the PS-88 perhaps the highest WAF -- Wife Acceptance Factor -- of any subwoofer made. I could actually envision someone buying two of these for the extra output and simply hiding them in the corners, daring people to find where the bass is coming from.
In some respects it is a niche product, but one that really has few equals. It's size, price and abilities form a unique combination. If you're in the market for a very small subwoofer that looks really nice, yet doesn't act small, the OSD PS-88 should be one of the first units you consider.