Just ordered a PSA (Power Sound Audio) 15S subwoofer (1 Viewer)

[Carlo_M]

In my room at my listening distance, and crossing over at 80hz, pretty much all subs are omnidirectional, regardless of driver orientation. Wavelength at 80hz=14.2 ft, 40hz=28.3 ft, and 25hz=44.8 ft. All of which are further than the sub will be positioned from the seating areas.

I have a front firing sub right now and I have never been able to close my eyes and locate where it is during normal movie/music playback.

 

[JohnRice]

In my opinion, location is the most I've been thinking over this discussion, and do have some of my personal observations to contribute, but I'm at work, so I'll do it later. There do seem to be some universal goals, though. 1) You don't put the sub equal distance from any two surfaces, and I've found it's best for there to be no two surfaces that are anywhere near equal. 2) You need to give anything that is moving air (driver and ports) plenty of room to breathe. EX: if the port(s) is in the back, you need to give some room behind the sub, or it will tend to have a hollow sound.

Anyway, I'll toss in my personal, general suggestions later, when I have time.

 

[Carlo_M]

Looking forward to it, John. In my current place I have very limited options, which is why I chose a sub with some flexibility in terms adjustments. The Hsu has a Q control knob, Rythmik has a knobs for bandwidth and frequency, and PSA has "room size". I'm going to have to use my Audyssey in my Denon 4400, as well as the PSA's controls, to try and optimize the sound in my seating area, because I don't have a lot of options in terms of placement.

 

[JohnRice]

Carlo, all that stuff is great, but I can't imagine how anything electronic can overcome physics. I could be wrong, but where subs are concerned, placement has to be first and foremost. The electronic adjustments, it seems to me, are for fine tuning once you have the best placement you can achieve.

 

[Carlo_M]

Sure John, there's the ideal and then there's real world. I'd love to get the ideal placement. But in my living room, there are real world constraints that prevent that. Given that, I'll have to resort to real world alternatives to mitigate [to whatever extent is possible] a suboptimal placement.

Maybe this wasn't clear: I do not have a dedicated HT room. It's a living room, which serves multiple functions. As such, I don't have flexibility to place things exactly where I want, or where measurements (or a subwoofer wall crawl) would indicate is optimal.

 

[Luke Cool]

Pretty much all subs are omnidirectional, regardless of driver orientation.

I have a SVS PB2000 in a 18 x 22' room. I can tell where it is, but only if I walk around. I also have a Velodyne front firing with a downward passive radiator in the same room, locating it is more difficult.

Even though bass its self is more so omnidirectional, the speaker that produces it is not. Walk to the side of any speaker, and sound levels are different than they are in front of it. With downward firing, you're at the side no matter where you sit, so sound levels are the same in any direction. Distance is another story. So to be more precise, the sound level is omnidirectional.

Carlo, all that stuff is great, but I can't imagine how anything electronic can overcome physics. I could be wrong, but where subs are concerned, placement has to be first and foremost. The electronic adjustments, it seems to me, are for fine tuning once you have the best placement you can achieve.

Excellent advice. One can fudge the other a little, but that's not the intent of their purpose. Your not wrong.

 

[JohnRice]

Carlo, the location of drivers and ports will always influence how a sub should be placed in a room. Most of the time they aren't really omnidirectional. Your new sub, however, has a downward firing driver and a sealed enclosure. To me, that does make it essentially omnidirectional, which I think makes placement more flexible.

 

[JohnRice]

BTW, when I was looking at Carlo's new sub, a chat from Tom V popped up. I've been looking at their subs for a couple years now, but when a chat popped up I never noticed it being Tom. Anyway, we had a short chat. He didn't ease my urge to upgrade to their S3000i over my SVS PB12 Plus/2, which Tom also designed. I'll have to "earn" that upgrade, if I'm going to justify it. Maybe I'll seek out some photography work this summer.

 

[Carlo_M]

The 18"s didn't tempt you?

(if size were not an issue I'd probably have been looking at 18" drivers)

 

[Mike Frezon]

You are obstinate to almost every poster. These people are trying to help you, but it seems you already have all the answers you want, and you have every thing already figured out. If you didn't want help, why'd you post this thread. It sounds like to me, with the space limitations you have to deal with, your new sub may sound better than the old one, but you will never hear it at its best.

"Obstinate to almost every poster?" I had to see if I was reading the same thread as you, Wes.

I'm not Carlo, but it seems pretty obvious to me that he wanted to post about his new toy and walk us through the process of the purchase and then of the set-up. Personally, I love these kinds of threads and don't presume to have all the answers about the best ways to buy or install.

It also seemed to me that Carlo took your opinion about the platform/carpet underneath seriously...seeing as how he had a conversation about it with Tom V. And I have seen nothing but polite, interested responses from Carlo throughout this thread. He explains that he's got limitations on placement and you interpret that as some kind of intentional pushback to your suggestions. Not all of us can have things in our HT as perfect as others might think we should.

So I'm not sure what your problem here is...but I'll tell you mine. We have rules about civility in posting here and name-calling is on the list of "don'ts." So, don't.

 

[JohnRice]

FWIW, I don't feel Carlo has been obstinate to anything I've said. We are working our way around some details, and that tends to lead to some misunderstandings of what's being expressed. What I find an awful lot of the time is not that what someone says is exactly wrong, but that it's incomplete. Such as in this very thread, the intricacies of bass and subs. Bass notes are somewhat non-directional, but not entirely, and subs are less directional than other speakers, but not entirely, in most cases. When I looked up this particular sub and saw it's basic design, then I realized it basically is omnidirectional. Why? Because a sub that either has the driver and port(s) in the bottom, or a down firing driver in a sealed cabinet is going to radiate in all horizontal directions equally. It seems that a lot of the time people ignore the placement of the ports when they consider where to locate the sub, but they're as important as the driver(s).

Anyway...

My main point to Carlo about placement is, get the placement as good as you can first, within your limitations, then do the electronic fine tuning.

 

[Carlo_M]

And that is definitely the plan, John. If only FEDEX would stop taking their sweet time and deliver it already...

 

[JohnRice]

Carlo, here are my gut feelings on where to start with the sub. I'd put it toward a front corner, close (2-4" to start) from one wall, probably the front wall, and 2-3' from the side wall, if you can. The other two walls will be far enough away not to be a factor and if the room is rectangular you should be in good shape. We'll call the side of the sub with the amp on it the "back", which I'd turn to the outside wall, only so you see finished sides of the sub in the room, and you can get to the amp without having to move it.

An alternative is in the corner, just a few inches away from the two walls. If the room is square, that might cause a problem, but with this particular sub, it's a viable option. Not ideal, but not horrible.

 

[Carlo_M]

What you describe re: placement near back wall is actually where my current sub is. Due to limitations though it's also bounded on one side by one of my floorstanding towers, but on the other side is my AV rack that is elevated by it's stands 1 foot off of the ground and there is nothing on the first foot of it, so the sub will essentially be unblocked on that side.

 

[JohnRice]

To nit pick, I wonder about vibrations with disc players being close to the sub, which is one reason I have my sub on the opposite side of the front wall from the electronics. Like I said, this particular room is especially ideal for an HT, a lot more than what most people have available, plus it's a dedicated room, so there is a lot more flexibility than most situations.

It sounds like a good situation, though. If the sub sounds "hollow", then experiment with moving it around a little. An inch or two can make a big difference. Get something you like, then run your Audyssey or whatever compensating software you have. I still haven't done Audyssey with the new Pre-pro.

 

[Carlo_M]

It's hard for me to explain the setup. It's a stand made of all steel, but the only part of it that touches the carpeting on the floor are on spikes. My disc player and amp are two levels up from the bottom, and the amp anchors the whole thing down. I've never had problems with vibration on it (I've even had a turntable on it which is very sensitive to vibration but had never skipped). I've moved the TT to another room though.

 

[JohnRice]

It sounds good to me. Holy smokes, you're gonna love that new sub.

 

[Carlo_M]

Got here right at 5PM. To quote C3PO..."typical".

 

[DaveF]

The simple recommendation is to put the sub where you can: most people only have one or two practical places for it. Set the cutoff to 80 Hz. And then run Audyssey. If you have time and enthusiasm, you can get more involved, including tuning the sub cutoff, possibly adjusting its porting (if that's a feature it has), and so on.


I've read over the years that you can place your sub in your seating location and then listen from prospective speaker locations. The one that sounds the best is the optimal location for the sub. Reversability of Rays and all that, from wave propagation physics (strictly speaking, I'm not sure it's truly correct due to diffraction, but I've never taken time to check the math )

Back when I was a penniless grad student, newly found HTF, and had my first $100 KLH sub, the recommendation was to stuff the box with insulation to dampen vibrations and to put the speaker on a heavy paving stone: a $10 upgrade to a cheap speaker. I did those and enjoyed them for some years.

Subsequently, I bought am SVS cylinder sub. At that time, I don't recall anyone talking about carpet being a problem. And in that time frame, my perception was that cylinders were far and away the preferred choice for enthusiasts over box subs. In any case these days, you can buy cylinder or box, ported or sealed, and get your desired tradeoff between size and power and cutoff frequency and price.

In any case, on house carpeting, I've had zero issues with a downward firing cylinder sub.

 

[JohnRice]

Dave, in a certain way, your first statement seems to support the belief I'm seeing more and more around here to not even try (or suggest to anyone else) to do anything better than what's the easiest. Read the first sentence of your post again before telling me I'm wrong. What's the point of this forum if the answer is just to "put the sub where you can"? If that's an answer to give, then why ask, and why have the forum in the first place?