# SVS vs HSU Question (yea, I know.... another one)



## Vader (Jul 8, 2006)

Hi all,

A friend of mine is currently researching a future upgrade to his current sub (I don't remember which), and was commenting how awesome my dual SVS cylinders sound. The other day he asked me a question to which I have no answer, and I was hoping that some of the more knowledgeable bass-heads here could help out. He directed me to a thread on AVS that claims the Hsu VTF-3 HO w/ Turbocharger is rated for 6000+ ft^3 rooms. If I am reading the specs correctly, it is a single 12" woofer, correct? And the primary function o fthe turbo is to increase the port space, thus increasing SPL at low frequencies? When I started with a single cylinder in a 3200 ft^3 room, I was able to get it to cry uncle several times between "War of the Worlds" and "The Incredibles" (at about -10dB below RL), and Ron and I agreed that duals would be my best bet. My friend asked me why use dual 12" drivers, when a single 12" (with this turbo thingy) is aready capable of filling a room twice my size (and for $800 cheaper, he was quick to point out). Thanx!

Edit: My friend's current sub is a Boston Accoustics PV400


----------



## drdoan (Aug 30, 2006)

Derek, sorry, but, I haven's heard the HSU's. But, as you probably know, it is a matter of moving air-the more air you can move, the more bass will be heard and felt. Although larger port size and cabinet volume does lower the response, I don't see how it can increase air flow as much as compared to more drivers moving more air. I would look at the published specs for each and then find as much independent tests that back up the specs. Let's face it, a 2" inch $.75 speaker can produce 20hz, but, the amount of air it can move is so small that it wouldn't disturb a mouse. I am not disagreeing with HSU, just pointing out that air must be moved. I have read quite a few good comments about HSU. I personally own the SVSound PB12-Plus/2 with the new woofers. In my smalish room, it is a visceral experience! Another point is the WAF. The twin cylinders will probably pass more than the large box's. Dennis


----------



## Vader (Jul 8, 2006)

Thanks, Dennis!

I do not doubt the HSU specs, and I too have never heard one (but based on the reviews I've read the SQ is also awesome). Being a sub noob with a strong physics background (me), that claim of being able to presurrize a 6000 ft^3 room with only a single 12" driver confused me somewhat (in light of the fact that I could make a single 20-39 cylinder sweat profusely in a room half that size). Is the HSO driver that much more robust than the 12.3? I mean, is it even physically possible for a single 12" driver to do that without massive distortion?


----------



## drdoan (Aug 30, 2006)

I suppose HSU's driver could be better, but, based on my dealings with SVSound, I would tend to think that the 12.3 is going to be pretty hard to beat. Dennis


----------



## Blaser (Aug 28, 2006)

Vader said:


> Hi all,
> 
> A friend of mine is currently researching a future upgrade to his current sub (I don't remember which), and was commenting how awesome my dual SVS cylinders sound. The other day he asked me a question to which I have no answer, and I was hoping that some of the more knowledgeable bass-heads here could help out. He directed me to a thread on AVS that claims the Hsu VTF-3 HO w/ Turbocharger is rated for 6000+ ft^3 rooms. If I am reading the specs correctly, it is a single 12" woofer, correct? And the primary function o fthe turbo is to increase the port space, thus increasing SPL at low frequencies? When I started with a single cylinder in a 3200 ft^3 room, I was able to get it to cry uncle several times between "War of the Worlds" and "The Incredibles" (at about -10dB below RL), and Ron and I agreed that duals would be my best bet. My friend asked me why use dual 12" drivers, when a single 12" (with this turbo thingy) is aready capable of filling a room twice my size (and for $800 cheaper, he was quick to point out). Thanx!



Hi Vader,

I do not own either the HSU nor the SVS yet. But based on laws of physics, forums, reviews.... Let's make a small analysis comparing between HSU HO with SVS PB 12 + (but this is only "expectations"):

- SVS has more enclosure volume,
- SVS has 25 watts more than the HSU
- HSU has 18.5% more port area when all units are ports open, and 77% more port are in 16 Hz mode assuming turbocharger for the HSU.

While port area is important, there is a size limit for what ports can add (according to my readings). While the Plus has less port area in the 16 Hz mode, I don't think 2 * 3" ports is not enough for a 12" driver, and I did not read anyone has experienced Pb 12+ ports shuffing in the 16 Hz tune or whatsoever, nevertheless one can expect higher SPL (maybe 2 or 3 db) for the HSU around 16 Hz. 

But from the other side, SVS has a larger enclosure which is also a good thing for the lowest frequencies.

From the above, I expect both units to have quite similar SPL capabilities (in the native tune), and similar SPL capabilites at 16 hz tune at all frequencies except from 14 to18 Hz where the HSU would have a 2-3 db edge.

While HSU specifies the HO for Hudge rooms, there is no mention of the reacheable SPL (ex DD reference level).... or whatsoever And if the HO could fill a 6000 cu ft room, I think so would the plus be able to do:bigsmile:.

Pls check this thread where there is a rough comparaison between HSU HO, Ultra and Pb 12 + based on Ed Mullen review. FYI, there is a post where it is said the 12.3 driver is stronger than the HO driver (would provide 2 db above tuning), but some report the HO provides better SQ.

http://forums.audioholics.com/forums/showthread.php?t=20925

Last word: I am no expert.... I have never measured anything and I do not have any of these subs. My tools are only readings...

Hope this helps! 

Blaser


----------



## Vader (Jul 8, 2006)

Thanx, blaser!

After skimming that thread, I have a somewhat better understanding of what makes up the differences between what makes a sub sound great for music vs. movie use. And Craig does specify that multiple units (either SVS or HSU) would be required to reach RL, which was my original question. Bottom line: I would say that my use is 98% movies anyway, and as for the remaining 2% music, it still sounds awesome!


----------



## Blaser (Aug 28, 2006)

Vader said:


> Thanx, blaser!
> 
> After skimming that thread, I have a somewhat better understanding of what makes up the differences between what makes a sub sound great for music vs. movie use. And Craig does specify that multiple units (either SVS or HSU) would be required to reach RL, which was my original question. Bottom line: I would say that my use is 98% movies anyway, and as for the remaining 2% music, it still sounds awesome!


Of course, the HSU is a great sub, but the SVS also is, and in native tune.....I think would be very close!! Moreover, Ed review was with the old driver:T you know the remaining...

Blaser


----------



## Blaser (Aug 28, 2006)

Vader said:


> Thanx, blaser!
> 
> After skimming that thread, I have a somewhat better understanding of what makes up the differences between what makes a sub sound great for music vs. movie use. And Craig does specify that multiple units (either SVS or HSU) would be required to reach RL, which was my original question. Bottom line: I would say that my use is 98% movies anyway, and as for the remaining 2% music, it still sounds awesome!


Hey Vader!

How do you place your subs? Do you have 6 db reinforcement?

Did you try placement in opposite corner of the same wall? how much dbs does the second sub add in this configuration?

Did you try placement at each side of the center channel and between mains? 

Thanks!


----------



## Vader (Jul 8, 2006)

blaser,

The cylinders are co-located, and "kinda-sorta-use your imagination" corner loaded (they are about 7' from the nearest corner, about 12' from the listening position), and de-coupled from the floor. I do get the full 6dB boost in this config, which is good since I am somewhat limited as to where I can put them (for now, at least). The room FR (via REW) is not terrible, but I do need to get a BFD. My friend's room is smaller than mine (about 2200 ft^3), so he is looking at duals in opposite corners to try and smooth out the FR a little.


----------



## cyberbri (Apr 27, 2006)

_Edited by moderator since thread moved._


----------



## Vader (Jul 8, 2006)

Cyberbri,

_Edit by mod: some unecessary stuff removed._

Personally, I am not interested in all of the "xxx is better than yyy" nonsense, and love my SVS's to no end. But, at the same time, when a friend asks me a technical question which is honestly beyond me, I am not gonna default to the "In the beginning, God made SVS (or any other sub)..." position (or make something up) just because I swear by mine: I'm going to ask those who _do_ know. If I came across as if I have an agenda other than that, I sincerely apologize, my friend.

Thanx, all for the replys!


----------



## drdoan (Aug 30, 2006)

I am here because of the same reasons you state. I lingered here for a while to see if it was a forum I could be comfortable with. Not only is the advise given here great and as accurate as possible, but, the atmosphere is very refreshing. Dennis


----------



## cyberbri (Apr 27, 2006)

Vader,

_Edit by mod: (unnecessary comments removed)._

How about a professional review where a VTF-3 MK3, not even the VTF-3 HO, out SPLs an Ultra? The VTF-3 MK3 hit 109dB at 20Hz (at 17 feet in a large room), without the turbo - the Ultra did 106dB. Adding the turbo he got 112dB at 20Hz, more than any sub he's tested. The sub, w/o turbo, _cleanly_ reached 114dB at 31.5Hz. The HO keeps the same enclosure and has an upgraded driver.

This is like going to a Chevy forum and asking how a Ford XXX can possibly beat a Chevy YYY. And yet you don't want to hear "XXX is better than YYY." What kind of answer are you expecting? 


And how many people on this thread have actually heard the HO? onder: I guess you don't really want an answer, you just want to hear that there's no way a single-driver sub can outdo 2 subs. Would you believe it if the HO was more expensive than your 2 subs?


----------



## Vader (Jul 8, 2006)

Cyberbri,

I was asking on a physics basis what the differences are, not "which is better". Neither am I trying to prove that a single driver can never outgun dual drivers. You provided data on comparisons between the HO and the Ultra. Fine, I do not contest those. What a professional review does not do is provide the PHYSICS behind the difference. And given the general prose and immaturity of the majority of posters on many other foums, I would get only name calling and further SVS-bashing responses. 



> And how many people on this thread have actually heard the HO?


I'm sure you know that sound is a very subjective thing. What sounds good to me might sound like trash to you, or just sound bad in your enviroment. The reverse is also true. However, the laws of physics are not, and that's what I was inquiring about.



> Would you believe it if the HO was more expensive than your 2 subs?


Sure. Why not?



> What kind of answer are you expecting?


Pretty much what Blaser provided above in post#2.


----------



## cyberbri (Apr 27, 2006)

Vader said:


> Cyberbri,
> 
> I was asking on a physics basis what the differences are, not "which is better". Neither am I trying to prove that a single driver can never outgun dual drivers. You provided data on comparisons between the HO and the Ultra. Fine, I do not contest those. What a professional review does not do is provide the PHYSICS behind the difference. And given the general prose and immaturity of the majority of posters on many other foums, I would get only name calling and further SVS-bashing responses.


Actually it was the VTF-3 Mk3, not even the HO itself, that beat the Ultra in _clean_ SPL at 20Hz (and matched it at 31.5Hz). 

Anyway, if you want to ask about the physics of the HO, I again say why not ask Hsu themselves what makes the design of the HO so special it can produce so much output? 



> Pretty much what Blaser provided above in post#2.


That compared watts, enclosure size and port area, not enclosure design, port length (internally), driver design or driver efficiency. No offense to blaser, but he has not seen or heard a HO, and knows little about its design compared to the makers of the subwoofer itself, and yet says "I expect both units to have quite similar SPL capabilities (in the native tune), and similar SPL capabilites at 16 hz tune at all frequencies except from 14 to18 Hz where the HSU would have a 2-3 db edge." Then he links to an SVS employee's review of it. :scratchhead:

Yes, that is just a prediction, and possibly somewhat accurate. But again, why ask people who have never heard the HO, in a "SVS only forum," instead of asking "how does the HO do it?" in the forums of the makers of the sub in question itself? You don't even have to mention SVS. Just ask "how does the HO have the output of 2 12" subs? What makes it so special?" That's my only point... :scratchhead:


----------



## bobgpsr (Apr 20, 2006)

cyberbri said:


> (at 17 feet in a large room)


Way too many things going on in any room to carefully evaluate a subwoofer low frequency end maximum output. I would only give credence to outdoor 2 pi groundplane type tests. The Sensible Sound tests do not do a proper job of measuring this IMHO.


----------



## cyberbri (Apr 27, 2006)

bobgpsr said:


> Way too many things going on in any room to carefully evaluate a subwoofer low frequency end maximum output. I would only give credence to outdoor 2 pi groundplane type tests. The Sensible Sound tests do not do a proper job of measuring this IMHO.


You do have a point.
But this is a single pro reviewer who has reviewed multiple subs in his single room. He knows his room, and has seen what subs can do what in his particular room. It is anecdotal, yes, but that doesn't mean it's meaningless.


----------



## Vader (Jul 8, 2006)

My apologies to Sonnie, the Shack mods, and all of those who come here to escape the petty bickering and baseless accusations so common on most of (if not all) the other HT forums. I will take my leave before this thread degenerates further. Cyberbri, I am sorry you mis-interpreted my comments, and no offense was intended. Take care.


----------



## Josuah (Apr 26, 2006)

I didn't follow everything in this thread, but the Turbocharger is designed to decrease the tuning frequency of the Hsu sub, not increase its output (except for the frequencies that are now above the new tuning frequency). Correction: this should read except for the frequencies below the new tuning frequency.

Craigsub has done some subjective tests and frequency response measurements of many subwoofers and puts the Hsu slightly ahead of the SVS subs. I think you can find his thread on Audioholics.

And how much subwoofer you need depends not only on the room size but placement and listening distance. If you're sitting on top of the sub, you don't need as much sub.  Large rooms start to have room gain at a lower frequency, but that tends not to couple as well with a ported design, since the roll off is steep.


----------



## cyberbri (Apr 27, 2006)

Josuah said:


> I didn't follow everything in this thread, but the Turbocharger is designed to decrease the tuning frequency of the Hsu sub, not increase its output (except for the frequencies that are now above the new tuning frequency).


The Turbocharger is designed to allow more port area in Max Extension mode. Without the Turbocharger, you plug one port on the unit and flip a switch to re-tune the box. By adding the Turbocharger, you get the lower tuning point with more port area. This lets more air (equals SPL) through, meaning higher SPL if you look at the "clean" before distortion SPL - plays louder with less distortion at the tuning point.


----------



## drdoan (Aug 30, 2006)

This thread may be getting a little testy. Probably we should all stick to the original question and helpful answers to it. One owns SVS the other owns HSU. Both are tremendous values. Dennis


----------



## cyberbri (Apr 27, 2006)

Vader said:


> My apologies to Sonnie, the Shack mods, and all of those who come here to escape the petty bickering and baseless accusations so common on most of (if not all) the other HT forums. I will take my leave before this thread degenerates further. Cyberbri, I am sorry you mis-interpreted my comments, and no offense was intended. Take care.



:scratchhead: My point was that I was asking why you chose a SVS forum to ask about the design of a HSU sub. You say you don't like the "SVS bashing" on the HSU forums (as if pro-SVS forums, current forum notwithstanding) aren't anti-HSU. 

If you really just wanted to know how the HO could have so much output, you could easily ask that question on the HSU forums without bringing up SVS at all, if your intention really was just to ask "how the HO does it." 

By HSU's own description:


> The lowest bass comes from the port. You need large ports to move lots of low bass without port noise or compression. With the HO, we went to dual 4" ports, which nearly doubles the port size compared to the VTF-3 Mk 2.


(I own a VTF-3 Mk2). But more ports equals more air moved, equals more output.

If you think me saying you should ask about a HSU sub in a non-SVS forum are "petty bickering and baseless accusations," well then :dizzy: :duh: :huh: :scratchhead: :surrender:


----------



## bobgpsr (Apr 20, 2006)

I think the physics boils down to mid-bass (45 Hz) versus low bass (<20 Hz). Dual drivers, more amp power, larger enclosures, all really help make the biggest difference in the mid bass region. For ported subs at low <20 Hz tunes, larger port area lets you get more very low frequency(<20 Hz) SPL out of the sub without "chuffing" and other port sounds. Extending the port length to get such a low tune without plugging ports should, per physics, let you get more sound at the very low freqs (<20 Hz). Look at the LLT 18" driver sub with 8" dia port, water heater implementation by Steve Callas for max performance (without building a horn sub). :holycow:


----------



## cyberbri (Apr 27, 2006)

I'm just quoting HSU's description of the HO from its own product page. Take from it what you will, but this is their description of the HO's unique design, which seems to be what the OP is asking about.



> The lowest bass comes from the port. You need large ports to move lots of low bass without port noise or compression. With the HO, we went to dual 4" ports, which nearly doubles the port size compared to the VTF-3 Mk 2.
> 
> The patented linear motor used in the HO has an extremely low distortion over its full operating range. This complements the low distortion, high output low bass afforded by the patent pending bent port and turbo technologies.
> Read More
> ...


And for the HO with Turbocharger



> Adding the patent pending turbo doubles the port area for extended bass mode, allowing the VTF-3 HO to move as much air as four VTF-3 MK2 models in extended bass mode with the same level of port noise.
> 
> ...
> 
> Adding the patent pending turbo dramatically increases the low distortion low bass. With our previous VTF technology where the bass extension of the subwoofer is achieved by tuning the subwoofer 1/3 octave lower by cutting the port area in half, we achieved lower extension at the expense of maximum output with low port noise and compression. In the extended bass mode, the air now has to be squeezed through half the port area, doubling the air velocity. Port turbulence occurs at a much lower level. The turbo technology eliminates this deficiency by allowing both ports to remain open for the extended bass mode. Hence with the turbo, the HO can move the same amount of low turbulence air as two HOs without turbo. This represent a dramatic cost and space saving.



I believe the ports within the enclosure are extremely long, hence putting the driver on the side of the enclosure to allow for this (and hence the reason they are patenting the design).


I hope that at least makes the design goals and actual design of the HO and the turbo clear. (note that the VTF-3 Mk3 is the same as the HO, except with the VTF-3 Mk2 driver (which now appears in the VTF-2 Mk3 -- the HO driver is a better driver than the VTF-3 driver).


Also, if you want to pursue it more, here is a Secrets review of the initial HO:
http://www.hometheaterhifi.com/volume_13_1/hsu-vtf-3-ho-subwoofer-3-2006-part-1.html
Note that the driver used in this reviewed version is not the final driver in the released subwoofer, as they retooled the driver for better performance. The bench test results (again, with the old driver - I wish they would update the review with the new version) are there to check out.


----------



## cyberbri (Apr 27, 2006)

Perhaps this thread could be moved to the general Home Audio Subwoofers forum here, rather than where it currently resides...


----------



## bobgpsr (Apr 20, 2006)

cyberbri said:


> Perhaps this thread could be moved to the general Home Audio Subwoofers forum here, rather than where it currently resides...


Yes, this is not an SVS unique question. Thread moved to here -- Home Audio Subwoofers.


----------



## cyberbri (Apr 27, 2006)

Thanks!  Problem solved!


----------



## Sonnie (Apr 11, 2006)

Did I miss something :scratch:


----------



## cyberbri (Apr 27, 2006)

Sonnie,

This was a question about the Hsu HO, but it was originally posted in the SVSound forum here.


----------



## Blaser (Aug 28, 2006)

Cyberbri, Vader,

I have quickly read your comments, and will post some clarifications to my points when I will be stopping to work 18 Hrs a day:crying: 

Best Wishes!!


----------



## Blaser (Aug 28, 2006)

cyberbri said:


> Vader,
> 
> _Edit by mod: (unnecessary comments removed)._
> 
> ...


20 Hz does only tell a small part of the story. Moreover, this was in Festler's room, pls check this thread where there is no such thing as 6 db difference between the HO and the Ultra according to Craigsub. http://forums.audioholics.com/forums...ad.php?t=20925

i am expecting a honest answer!! Do you mean that peoples are not honest because this was an SVS forum:nono: This is not nice!! What is the problem? I can confirm to you that the HO is stronger than a Pb 12 NSD in an SVS forum, but can also have my first reply above in the HSU forum.... Forums location have nothing to do with it! 

And did you hear dual Pb12+onder: Indeed, not that nobody wants to hear anything like "no way a single-driver sub can outdo 2 subs", but simply if you read my points in my first post, you will understand why it is unlikely that the HO will have more SPL than dual SVS 

If the HO was twice or even ten times the dual SVS price, I would still not believe it.... Are you serious???:duh: Dual SVS with stronger drivers than the HO (not my comment, but Craigsub's), more than double the enclosure volume, more than twice the power, even more port area:huh: if you still think the HO is stronger, you are either joking, doing marketting for HSU or simply know nothing about subs !!

Pls let your comments be objective without thinking that the SVS forum is bad intentioned!


----------



## Blaser (Aug 28, 2006)

cyberbri said:


> Actually it was the VTF-3 Mk3, not even the HO itself, that beat the Ultra in _clean_ SPL at 20Hz (and matched it at 31.5Hz).
> 
> *You forgot to mention that according to HSU it has less mid-bass punch... Check HSU forum.*
> 
> ...


*Which 2 12" are you talking about is very important.... Cyberbri, Again, there is no such thing as magics a subwoofer will do, but there are things called driver parameter, enclosure dimentions, material size, port area.... that's it!:T * :[/QUOTE].


----------



## Blaser (Aug 28, 2006)

bobgpsr said:


> Way too many things going on in any room to carefully evaluate a subwoofer low frequency end maximum output. I would only give credence to outdoor 2 pi groundplane type tests. The Sensible Sound tests do not do a proper job of measuring this IMHO.


Correct!! This is what Craigsub managed to do (quite approximately), and showed the HO is not far stronger (if stronger) than the Ultra.... Hence my expectation that dual PC12+ will be definitely stronger than the, the Pb12+/2 (below 25 Hz), the Ultra 2 (below 25 Hz), the Ultra and also the HO.... Sorry Cyberbri!


----------



## Blaser (Aug 28, 2006)

cyberbri said:


> The Turbocharger is designed to allow more port area in Max Extension mode. Without the Turbocharger, you plug one port on the unit and flip a switch to re-tune the box. By adding the Turbocharger, you get the lower tuning point with more port area. This lets more air (equals SPL) through, meaning higher SPL if you look at the "clean" before distortion SPL - plays louder with less distortion at the tuning point.


Correct, but at the expense of some frequencies SPL capabilities (typically 22-32 Hz for a 16 Hz tune), whatsoever big the ports are! TRADEOFFS!


----------



## Blaser (Aug 28, 2006)

cyberbri said:


> I'm just quoting HSU's description of the HO from its own product page. Take from it what you will, but this is their description of the HO's unique design, which seems to be what the OP is asking about.
> 
> 
> 
> ...


Now this is pure marketting for HSU in this forum!! I think this post should be deleted!! Cyberbri, before you ask the expected question.... Here is the answer: should it have been an SVS products, I would have also asked for this post to be deleted!!

By the way, I am not surprized to learn that you have an HSU product, and of course you are wishing everybody to say that this is the best product in the world 

FYI, I had made my mind on dual HOs in my 2000 cuft room, as of course this is a great sub, I like the linear BL curve its driver has... But unfortunately ....:hissyfit:


----------



## Blaser (Aug 28, 2006)

cyberbri said:


> Perhaps this thread could be moved to the general Home Audio Subwoofers forum here, rather than where it currently resides...


I really wonder what the problem is?? Did you see any single post from SVS moderators? Did anybody offend HSU in the SVS forum??? Are you just fighting for fighting?? I think part of the question is related to SVS.... Is it forbidden to ask about a sub in the SVS forum? 

Instead of fighting for moving this thread, let us know your scientific input and advise, concentrate on the original question, comment with an objective approach instead of constantly asking to move this thread, contact HSU ....

Cyberbri, I really have nothing against you, and sorry if I am too direct, but I wish you could technically justify the idea that the HO could be stronger than dual PC 12+.


----------



## cyberbri (Apr 27, 2006)

blaser said:


> 20 Hz does only tell a small part of the story. Moreover, this was in Festler's room, pls check this thread where there is no such thing as 6 db difference between the HO and the Ultra according to Craigsub. http://forums.audioholics.com/forums...ad.php?t=20925


Link is broken.  



> i am expecting a honest answer!! Do you mean that peoples are not honest because this was an SVS forum:nono: This is not nice!! What is the problem? I can confirm to you that the HO is stronger than a Pb 12 NSD in an SVS forum, but can also have my first reply above in the HSU forum.... Forums location have nothing to do with it!


There's "honest," "un/biased," "right/correct," "wrong," "partially right/wrong." I never said that people aren't being "honest." I said you don't go to Ford to ask what's good/bad about Chevy. And vice versa. You may get the "truth," but only part of the "truth." You have to take everything with a grain of salt. As I said over and over, I don't think a SVS forum is the place to ask about Hsu subs, and I don't think a Hsu forum is the place to ask about SVS subs. Going to the manufacturer, or a "neutral" forum, is IMO a much better choice than going to the place where the direct competition is exclusively discussed. That was my point - move the question/thread out of the forum with the description _The Sound Authority! SVSound offers the most popular subwoofers. Discuss the awesome SVS subwoofers here._ And it was moved. Problem solved.




> And did you hear dual Pb12+onder: Indeed, not that nobody wants to hear anything like "no way a single-driver sub can outdo 2 subs", but simply if you read my points in my first post, you will understand why it is unlikely that the HO will have more SPL than dual SVS


It's unlikely? Based on an comparison of _part_ of the data...
I never said it was one way or the other. Just that you only looked at part of the picture.

As an example, take 2 subs with identical enclosure sizes, ports, and watts. One driver has a sensitivity of 90dB, and the other 93dB. Without looking at the efficiency it looks like they would be even in output. But one is actually capable of 3dB more output than the other. 




> If the HO was twice or even ten times the dual SVS price, I would still not believe it.... Are you serious???:duh: Dual SVS with stronger drivers than the HO (not my comment, but Craigsub's), more than double the enclosure volume, more than twice the power, even more port area:huh: if you still think the HO is stronger, you are either joking, doing marketting for HSU or simply know nothing about subs !!


So more drivers/space _always_ wins? 

And to repeat, I never said one was better than the other. I was providing counter-data to your claims. 




> Pls let your comments be objective without thinking that the SVS forum is bad intentioned!


Again, I never said it was bad-intentioned. I just stated that asking in a Hsu forum would be a better option to ask about the design of the Hsu, and asking in a "neutral" forum would be more suitable for asking about a comparison.


----------



## cyberbri (Apr 27, 2006)

blaser said:


> You forgot to mention that according to HSU it has less mid-bass punch... Check HSU forum.


How is that "forgetting"? I was talking about output at 20Hz.




> What do you mean by enclosure design if Watts, enclosure size and port area are not important????


As I said in a previous post, there is more to it than that. Enclosure design is very important, as is driver efficiency and build. Which you yourself talk about below.



> > port length (internally),
> 
> 
> This is not important as we know the tuning frequency for the subs


I contend it is, because enclosure size is also compared. They are inter-related. Better ports means you can do more with smaller enclosure size, does it not?



> > driver design or driver efficiency. No offense to blaser, but he has not seen or heard a HO,
> 
> 
> So what, will laws of physics change if I had??


"So what?" you say. I said this in my previous reply. But if you take 2 subs with the same enclosure size, design, and amp wattage, but one has a better, more efficient driver, it will put out more SPL. You can't compare stats and predict SPL without factoring in the build and efficiency of the drivers themselves. 



> What do you mean by an SVS employee??? Are you putting the credibility of Ed Mullen in question Again, not nice from you!!! Moreover this review is much before his new position at SVS, so pls no need for such comments


I am not questioning his credibility. But he is an SVS employee, so you have to take what he says with a grain of salt. 2 companies may have experts in their fields, but what happens when they both say their product is better? Who do you believe then? :dizzy: 

I did not know the comparison was before he started at SVS. I think the link you provided was broken, so I couldn't view it anyway. 



> Which 2 12" are you talking about is very important.... Cyberbri, Again, there is no such thing as magics a subwoofer will do, but there are things called driver parameter, enclosure dimentions, material size, port area.... that's it!


Yes, exactly. A single SVS/HSU could smoke 2 12" $150 Daytons.

But your comparison didn't take into consideration the drivers themselves, just watts, enclosure size, and ports. Do you know the sensitivity ratings on the drivers?


----------



## cyberbri (Apr 27, 2006)

blaser said:


> Now this is pure marketting for HSU in this forum!! I think this post should be deleted!! Cyberbri, before you ask the expected question.... Here is the answer: should it have been an SVS products, I would have also asked for this post to be deleted!!


The OP was asking about the design of the HO and what made it "special." Conjectures were made based solely on enclosure size/volume, ports, and watts, without taking into consideration the design traits themselves... So I posted information about the design traits and goals of the designers, and labeled them as such. I don't see what the problem is. If this was about speakers, and a certain speaker had a special chamber design or special driver construction, would it be wrong to copy/post that description to convey that information?




> By the way, I am not surprized to learn that you have an HSU product, and of course you are wishing everybody to say that this is the best product in the world


If the forum doesn't matter one single bit, why should the "products owned" matter at all, by your own logic.

I never said or claimed one was better. I stated that I thought questions about "what makes the design of the HO so special" be asked of Hsu folks, and/or a product-neutral forum, not a direct competitor's forum labeled "direct competitor has the most popular subs around - talk about these awesome subs here." Just like I would question someone asking about Ford in a Chevy forum, or the PS3 in an Xbox forum. How hard is that to understand?



> FYI, I had made my mind on dual HOs in my 2000 cuft room, as of course this is a great sub, I like the linear BL curve its driver has... But unfortunately ....:hissyfit:


Unfortunately what? :scratchhead:


----------



## cyberbri (Apr 27, 2006)

blaser said:


> I really wonder what the problem is?? Did you see any single post from SVS moderators? Did anybody offend HSU in the SVS forum??? Are you just fighting for fighting?? I think part of the question is related to SVS.... Is it forbidden to ask about a sub in the SVS forum?


No, the SVS owners have not commented here. I just raised counter-points to your arguments and asked the thread be moved into a neutral forum. That's all... 




> Instead of fighting for moving this thread, let us know your scientific input and advise, concentrate on the original question, comment with an objective approach instead of constantly asking to move this thread, contact HSU ....


:duh: It's already been moved...




> Cyberbri, I really have nothing against you, and sorry if I am too direct, but I wish you could technically justify the idea that the HO could be stronger than dual PC 12+.


I never said "never."
You arbitrarily selected the PC 12+ to compare the HO to. The OP mentioned the 20-39 in a subsequent post, but never explicitly said "my +." It was just "how can a single 12" outdo 2x 12"s?"

Here is the OP's question:


> A friend of mine is currently researching a future upgrade to his current sub (I don't remember which), and was commenting how awesome my *dual SVS cylinders* sound. The other day he asked me a question to which I have no answer, and I was hoping that some of the more knowledgeable bass-heads here could help out. He directed me to a thread on AVS that claims the Hsu VTF-3 HO w/ Turbocharger is rated for 6000+ ft^3 rooms. If I am reading the specs correctly, it is a single 12" woofer, correct? And the primary function of the turbo is to increase the port space, thus increasing SPL at low frequencies? When I started with a *single cylinder* in a 3200 ft^3 room, I was able to get it to cry uncle several times between "War of the Worlds" and "The Incredibles" (at about -10dB below RL), and Ron and I agreed that duals would be my best bet. My friend asked me *why use dual 12" drivers, when a single 12" (with this turbo thingy) is aready capable* of filling a room twice my size (and for $800 cheaper, he was quick to point out). Thanx!



The OP continued with this in a subsequent post:



> Is the HSO driver that much more robust than the 12.3? I mean, *is it even physically possible for a single 12" driver to do that without massive distortion?*


Therefore I took the question to be about the design of the HO enclosure and the driver, the enclosure, its efficiency, and its ability to produce SPL despite its "single driver design." If it is say 3dB more efficient than a different driver, then it can produce 3 more dB with all else (enclosure, watts, ports) equal. If due to enclosure and port design it can get 3 more dB before X% of THD, then that combines to get 6 more dB, equivalent of having 2 subs that are 3dB less sensitive. All hypothetically speaking, of course. 

That says nothing of the design of the enclosure or the build/efficiency of the driver. And without knowing all that, a simple watts-ports-volume comparison isn't valid, IMO. :surrender:


----------



## Sonnie (Apr 11, 2006)

Okay... I think the OP has his answer and we are now mostly fussing. Both of you guys have had your say on the issue. Let's just end it here and close the thread.

Although I know you guys have your differences and/or own opinions, please try to be friends. 

Thanks!


----------

