# Finalizing my Subwoofer Decision (I think...)



## Philm63 (Jan 1, 2015)

Ok, so the AVR has been upgraded to the Denon 4520, I added an Oppo 103D, the front 3 have been upgraded to the Chane A5rx-c's (L&R) and an A2rx-c (Center), the surrounds are Def Tech PM-800's (on-wall), but I'm still living with those two older, inadequate and grossly mismatched subs, one of which is now making a rather uncomfortable noise - I fear the old Klipsch is giving up the ghost.

Remembering back from my older posts; my room is large and open (>5000 cu ft - tall ceilings, etc.) and the two co-located but mismatched 10's just aren't doing it for me. Seeing as one of my current subs is on its last legs, I've picked up the pace on my research into a replacement. I intend, for now, to run with just one new sub to replace the two old ones, and have narrowed the field to the following three based on comparisons including size, power, frequency, and price (delivered):


SVS PB-2000: 12 inch, 500 W, 17 Hz (expect 2-3 deeper extension in-room); $800
HSU VTF-3 MK5: 15 inch, 600 W, 18 Hz (Ported), 22 Hz (Ported or Sealed); $888
HSU VTF-15H MK2: 15 inch, 600 W, 16 Hz (Ported, 22 Hz (Ported or Sealed); $1008

Not a lot of spread between prices, so any one of these would fit the budget. The low-end is very respectable on all three. The size of each cabinet and its associated WAF are quite acceptable for all three. 

What I am not sure of is the concept of "in-room extension" below rated frequencies, such as that stated in SVS's ratings for the PB-2000. What I _think_ this means is this; tests are done in anechoic or semi-anechoic conditions, and in a "real" room with reflections and open space, the rated frequency _could_ extend a bit lower.

I've done a fair bit of research but I'm still unclear on the importance of tuning the sub to the space (ported vs. sealed, or one or more of the ports plugged - assuming multiple ports; Q; etc.) This is an important factor in my decision on which sub to buy - would I benefit from having Q? Do I need a 15 inch driver or would a 12 do just fine for a hundred or two less? In the HSU's; is there really that much of a difference between 18 Hz and 16 Hz, and is that difference worth another 100 bucks? (I don't need the XLR inputs, BTW, so the difference in Hz is the only useful difference to me, I think...)

Also, should I expect a difference in my large open space between a 500 W, 12 inch sub and a 600 W, 15 inch sub with respect to how much air is being moved? Can I expect this difference to be noticeable - will I feel or hear a significant enough difference to justify the difference in cost? (cost is no longer the issue as I've narrowed it down to three within my budget - just looking to confirm where the $$$ are going).


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## theJman (Mar 3, 2012)

The PB2000 is certainly a nice subwoofer, but unless you're going to use at least a pair your space is simply too large for it to operate effectively. If you want noticeable bass response you'll really need to go with 15" or 18" drivers instead.

"In room extension" is, for all intents and purposes, a nebulous specification. Every room is different, so there's really no way to accurately predict what a sub will do once installed in your unique space. Notice how wide of a variance those companies quote for that number? It's because they're speculating 'based upon an average room'. But what does that entail precisely? Is there such a thing as an average room? Personally, I don't believe that exists. You should take those numbers with a grain of salt.

Anechoic measurements are more common with speakers than subwoofers, mostly because the former lends itself better to that type of testing. Subs, on the other hand, are generally measured at 1 or 2 meters GP (Ground Plane). In essence what that means is the unit is placed outdoors - far from any physical boundary - and then the microphone is placed on the ground 1 or 2 meters away from the driver (hence the term 'ground plane', because the 'plane' of the microphone is directly in front of the driver and it's on the 'ground').

Air movement is dictated by driver size, not amp wattage. The larger your driver the more air it can displace. It's all down to physics.

One final note... along with the subwoofers you mentioned you ought to check out the PSA XV15 and V1500. Both are highly regarded subwoofers and within your price target.


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## tonyvdb (Sep 5, 2007)

Jim, quick question would the SVS not have the same output given that the driver excursion may be more than the other two?


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## willis7469 (Jan 31, 2014)

tonyvdb said:


> Jim, quick question would the SVS not have the same output given that the driver excursion may be more than the other two?


 I was going to ask this too.


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## Philm63 (Jan 1, 2015)

theJman said:


> ...If you want noticeable bass response you'll really need to go with 15" or 18" drivers instead. ...Air movement is dictated by driver size, not amp wattage. The larger your driver the more air it can displace. It's all down to physics.


So it is to say the size of the driver is the main contender when needing to push a lot of air (hence pressurizing a lot of space), not necessarily watts, no? I just stumbled upon Reaction Audio's Echo 15 - it is within budget, but I don't know much about this one yet. And then there's RA's Echo 18 - a bit over my budget, but wow!



theJman said:


> One final note... along with the subwoofers you mentioned you ought to check out the PSA XV15 and V1500. Both are highly regarded subwoofers and within your price target.


I'll certainly add these PSA's to my list, thanks!


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## Philm63 (Jan 1, 2015)

tonyvdb said:


> Jim, quick question would the SVS not have the same output given that the driver excursion may be more than the other two?





willis7469 said:


> I was going to ask this too.


So this brings a new variable into the mix; I hadn't been thinking about excursion, not knowing this was also a factor in moving that air...

I'm really starting to think about 15 inches as a minimum now, seeing as I am only going to go with one sub in this application (the HT basement build will get 4, I'm sure...)


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## tonyvdb (Sep 5, 2007)

My understanding is with SVS is thats how they get so much more out of a smaller driver is because the excursion of the drivers are more than normal.


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## chashint (Jan 12, 2011)

I wouldn't count on picking up any low frequency extension in a large open room from any subwoofer.

I do not know what your expectations from a sub is but I wouldn't necessairly rule out the 12" subs.

My room is about 4800^ft plus it's open to the rest of the house.
I have a single Outlaw LFM1+.
I feel the low frequencies but I do not get a kick in the chest.
In Finding Nemo when the girl taps on the aquarium I feel waves of bass.
In WOW pod scene the whole room shakes.
I sit ~14 ft from the sub.
My sub is +2dB hot compared to the mains so it's pretty well level matched. 

My wife doesn't really like to feel the bass and points it out when she does, I just give her my dumb grin every time we watch a sci-fi or action movie. 

When I read about some of the sub setups various people have I often wonder if I would like it or be overwhelmed by it.
I know my wife wouldn't like it at all.

I recommend sticking with well established and well reviewed brands.
The Hsu and SVS subs certainly fall into that category.
I have read great things about the PSA but don't know any of their history.


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## willis7469 (Jan 31, 2014)

Philm63, to your question about "tuning the sub". When you run all ports open, that's usually the stock configuration. When you plug ports, the frequency response lowers, and eventually you'll end up sealed (if the unit supports). What happens is, you trad output for extension. For example, if I plug 2 of my 3 ports, the tune goes from 20 down to 16hz. Extension is increased, but overall output in this lower range is reduced. Theoretically room gain should assist in restoring some of that, but in a large room(like mine/yours) if your running one sub, you should not tune it that low. The extra output will more than make up for a few hz. Now, if your talking about 4 sealed 18's....


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## Philm63 (Jan 1, 2015)

willis7469 said:


> ...The extra output will more than make up for a few hz.


Could this mean that looking for the lowest Hz rating in a sub is not the most important? I mean sure, it is important in some respects, but if Sub A was rated down to 18 Hz and Sub B 16 Hz, but Sub A had better numbers regarding output, would I be better off selecting Sub A for a large room, all else being equal? Just want to be sure I am looking at this correctly.

If one were to rank features for a sub (to be used in a large room) like extension, excursion, driver size, and amplifier type and power, how would that look?


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## theJman (Mar 3, 2012)

tonyvdb said:


> Jim, quick question would the SVS not have the same output given that the driver excursion may be more than the other two?


You're assuming the SVS driver has more travel, which may or may not be the case. Either way... there's a _lot_ to that equation but the short answer is no, the movement of air is not completely dictated by the amount of travel a driver has. Think in terms of a fan; one with a 12" blade span running at 3000RPM will not move as much air as a 15" unit running at 2500RPM. And definitely not if the latter is running at the same RPM. Why? Cubic volume of the source. Regardless of how much the smaller driver (fan) moves it still only has 12" of surface area to work with. Immutable laws of physics dictate how much can be derived from an originating source, no matter how it's tweaked or tuned. You can circumvent aspects of that - by using designs like an LLT for example - but ultimately the limits imposed by the source will come into play. You simply can't prevent it.




Philm63 said:


> So it is to say the size of the driver is the main contender when needing to push a lot of air (hence pressurizing a lot of space), not necessarily watts, no? I just stumbled upon Reaction Audio's Echo 15 - it is within budget, but I don't know much about this one yet. And then there's RA's Echo 18 - a bit over my budget, but wow!


Jeremy's initial offerings last year were a bit rough, but his Echo line is definitely a step in the right direction. That's a custom driver from none other than Pierce Audio (I know, because I introduced him to the company ). Paul Pierce does some incredible work, so Jeremy is starting in the right place. Reactions new amp appears to be a solid choice as well. Combined, that's probably a nice combo. Not quite SVS/HSU/PSA nice I imagine, but knowing Jeremy there will be a lot of value in those units.




tonyvdb said:


> My understanding is with SVS is thats how they get so much more out of a smaller driver is because the excursion of the drivers are more than normal.


That may be true - JL Audio subscribes to the same school of thought - but physics cannot be denied. At some point you have to pay the piper, so to speak.




Philm63 said:


> Could this mean that looking for the lowest Hz rating in a sub is not the most important? I mean sure, it is important in some respects, but if Sub A was rated down to 18 Hz and Sub B 16 Hz, but Sub A had better numbers regarding output, would I be better off selecting Sub A for a large room, all else being equal? Just want to be sure I am looking at this correctly.


Given your room size, and assuming just one subwoofer, then output is probably going to be more significant then a few extra Hz. The difference between an F3 of 16Hz and 18Hz will be subtle, but a subwoofer running out of steam will be less so. That tends to be more pronounced.


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## 480dad (Jan 22, 2015)

Each of the subs you're looking at are great and you'll hear a big difference between what you have now and which ever you choose. You do have a large room and you'll need to push more air to feel the slam but that doesn't mean you won't enjoy a nice low end upgrade. 

One reason I ended up with PSA is you can try their subs at no risk, no cost for 30 days. They cover shipping both ways if it just isn't what you are looking for. I have a 7,200 cu ft room and I ordered the xv15se to start with. A crazy, amazing difference over the two Polk ported subs (12" & 10") I had. When they introduced the new 15" ported sub (v1500) with the 750w ICE amp I decided to exchange the xv15se for it. I liked it so much I ended up with two. PSA's owners are former heads of R&D for SVS so the company may be semi-new but Tom Vodhanel and Jim Farina are not new to the sub business.

The hsu-15h mk2 is an awfully nice sub. As I said, you really can't go wrong.


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## 480dad (Jan 22, 2015)

This gives you some side by side comparison.


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## willis7469 (Jan 31, 2014)

To me, yes sub A would be the one. Wrestling with 2hz extra extension in that size room with a single sub is splitting hairs. Extension takes excursion, and that takes power. In your price range, I think in order to maximize output and extension, you'll be best served with a 15". 
12's are a good choice too, but in that big of a space you'll need the efficiency of the 15.


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## willis7469 (Jan 31, 2014)

But Jim, what if the blade pitch on the smaller fan were steeper? This would change the output of air. It takes more power to turn steeply pitched blades, so in my brain that equates to excursion.


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## chashint (Jan 12, 2011)

Even the worst one of the bunch you are looking at is a very good subwoofer.

if the difference in $$ and the size of the unit makes no difference to you I would vote to go with the bigger unit.

I would look for a reliable 3rd party review with ground plane measurements.
Some vendors are pretty creative with their frequency response specs.

Databass may have all the subs you're looking at on file.


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## 480dad (Jan 22, 2015)

Good advice Charlie. Always the straightshooter. I've come across a little headstrong for PSA and I didn't want it to go that way. :whistling:

Just bad news when you have to choose between a SVS, HSU, PSA, Rythmic, (insert other great sub here),...that's some tough sledding. :T


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## jamesfrazier (Jul 24, 2011)

I can't see a subwoofer thread without mentioning reaction audio. What they're doing for the money is pretty surprising. Check them out. 
With your budget look at the echo 15.
http://reaction-audio.myshopify.com


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## theJman (Mar 3, 2012)

willis7469 said:


> But Jim, what if the blade pitch on the smaller fan were steeper? This would change the output of air. It takes more power to turn steeply pitched blades, so in my brain that equates to excursion.


Your question is legit, and design variations like that are precisely why I threw in the caveat _"Immutable laws of physics dictate how much can be derived from an originating source, no matter how it's tweaked or tuned. You can circumvent aspects of that - by using designs like an LLT for example - but ultimately the limits imposed by the source will come into play. You simply can't prevent it"_. In essence you can forestall the inevitable, but in the end it is still inevitable.


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## willis7469 (Jan 31, 2014)

Hey Jim, I was half ribbing you, but thank you for answering straight up. I do agree with you. For that much room, a single sub, he needs the biggest driver he can get. As much as I'm a fan of SVS's plus, ultra and 2k series he would need at least two. Way over budget. I think if he could budget in the future for a 2nd would solve some issues too.


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## chashint (Jan 12, 2011)

Info on various subs.
http://www.data-bass.com/systems


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## Philm63 (Jan 1, 2015)

How does power play a role in subwoofer design? 

Does more power result in faster responses from the driver (more accurate – the ability to achieve “tighter” bass)? I think of this concept as having two basically identical cars, but one with 200 hp and the other with 400 hp. They might have identical top speeds (excursion), but the one with more power can accelerate much faster thus it will attain that top speed faster. Assuming this would be a good thing.

Or does more power merely allow higher excursion? I think of this concept as the power needed to move the coil from x-min to x-max. Seems to me it shouldn’t take that much power to move the coil a little bit (let’s say, 0.1”), but it might take significantly more power to move that same coil a lot (let’s say, 1.0”). I may be totally off on this – I realize there is likely much more to it – but I think I’m at least close to the mark here.

Or is it both?

Are there significant advantages of “direct servo” vs. “conventional” subwoofers? It is about efficiency? Accuracy? How come Direct Servo subwoofers have lower power and excursion ratings? Does output suffer?


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## theJman (Mar 3, 2012)

willis7469 said:


> Hey Jim, I was half ribbing you, but thank you for answering straight up.


I walked right into that. 

Ironically, the question really does have merit. The angle and even the shape of a fan blade changes it's dynamics, so it might not have been as far-fetched as you thought.


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## theJman (Mar 3, 2012)

I think you get the 2015 award for most questions asked in a thread... 

The amp does play a role in the overall performance of a subwoofer, but it's a holistic system where you get results from the _sum_. In other words, taking any one part in isolation gives you an incomplete picture. The wattage wars are a perfect example.

Too many people are under the illusion that they can derive some measure of performance by merely looking at the amps wattage rating, or can discern an advantage between two subwoofers because one of them has more wattage. Neither of those is true. You have to account for alignment type, driver efficiency, T/S parameters, cabinet volume, and on and on. Basically the system has to be taken as a whole, and even then speculating based solely upon numbers is a fools errand.

Take your car example. You see two different vehicles that have identical 0-60 times, but what does that tell you? It says they get to 60MPH in the same span of time, but what it can't tell you is _how _they get there. Is one faster off the line and then slows down? Is the other smooth and steady or difficult to control? What is the aural sensation? Do either have a deep rumble, or do they sound like a jet turbine?

By now you probably get my point; you can look at charts, graphs and numbers until your eyes cross, but that will only take you so far. You have to dive in and experience something in order to know what it can truly do. And what appeals to me might not do the same for, so that further complicates the equation. I'm not advocating you don't do the research - far from it, actually - but what I am saying is in the end the only thing that matters is what works for you. Data alone can't answer that question I'm afraid.


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## willis7469 (Jan 31, 2014)

Once again, have to agree with Jim here. The only thing I'll be able to add, is that better amplifiers provide better control over the driver. This is not a function of pure power, but it is part of the design overall. To comment on your question about servos.(as I understand) The "servo" is a feedback circuit that goes to the input from the output. When that senses distortion it alters the output signal to make it match the input signal. This is about control, and by limiting distortion, you can send more power to the driver. (Up to a point) that's my "nutshell" ,"as I understand". Not sure about the power ratings. As Jim said, it's all about being more than the sum of ones parts.


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## willis7469 (Jan 31, 2014)

theJman said:


> I walked right into that.  Ironically, the question really does have merit. The angle and even the shape of a fan blade changes it's dynamics, so it might not have been as far-fetched as you thought.


 Where I initially came from with that was boat propellers actually. But it's the same idea. Glad your a good sport!
Cheers!


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## chashint (Jan 12, 2011)

480dad said:


> I've come across a little headstrong for PSA and I didn't want it to go that way. :whistling:


I didn't read it as headstrong. 

When I started looking at subs was in the timeframe of when a couple (or three) ID sub manufacturers were beginning to implode. 
As I recall two of the vendors left customers without working subs or refunds and the other just stopped taking orders.
All three had very highly rated products and an army of fanbois defending everything right to the very bitter end.
If the implosions had not occurred when they did I would probably be stuck with a (MFW ? or Elemental Design) sub.
If it was working I guess that would be OK, but odds are it would be dead.
I am just cautious about investing with the new subwoofer kid.
Having said all that. 
PSA seems to be very legitimate.
There's been no negative forum traffic and if the owners are former SVS designers they should know how to vet the products before bringing them to market and the price you have to pay in reputation as a company if the products are not reliable. 
If I were in the market for a sub I would certainly be considering them.
One thing I really like besides the numbers it produces is the downfiring design.


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## theJman (Mar 3, 2012)

chashint said:


> There's been no negative forum traffic and if the owners are former SVS designers they should know how to vet the products before bringing them to market and the price you have to pay in reputation as a company if the products are not reliable.


One of the guys who started PSA is more than just a former SVS designer, he's the V in SVS; Tom Vodhanel. There's definite pedigree in that company.


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## 480dad (Jan 22, 2015)

Speaking of Tom V., here's a good primer on a few basics I thought were helpful.

http://www.soundandvision.com/content/tom-vodhanel-president-power-sound-audio


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## chashint (Jan 12, 2011)

theJman said:


> One of the guys who started PSA is more than just a former SVS designer, he's the V in SVS; Tom Vodhanel. There's definite pedigree in that company.





480dad said:


> Speaking of Tom V., here's a good primer on a few basics I thought were helpful.
> 
> http://www.soundandvision.com/content/tom-vodhanel-president-power-sound-audio


Sweet info.
Thanks.


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