Which Sub to Get? HSU or SVS? Which Model?

[Peter Marcks]

Hello Rob! Nice to see you here, and great job moderating! This is a fantastic website, co-founded by Gene DeLaSalla who used to be one of the regulars at Audioreview.com many years ago, alias GDS. I remember Gene really went out of his way to help many people at AR.com, and that trend continues today at Audioholics.com!

A while ago, Dr. Hsu had been working on a new TN-X cylindrical subwoofer that would offer variable tuning in addition to some other nice features. The status of this project is really unclear at this time. Since most people seem to prefer the box subwoofers, Dr. Hsu has tried to concentrate on the new VTF HO box lineup. When the HO lineup is ready, then Dr. Hsu will have more time to think about a new cylindrical solution, and I will let you know more as soon as possible.

Sincerely,

 

[Peter Marcks]

Hello Tom

This model has been out for years...I guess we were ahead of our time. Some of the more astute DIYers have been posting "turbo built in" on these models now

The TN1220HO is actually a model that could be considered in a sense to have turbo built-in, as it has an extremely long port and native tuning below 18Hz. This model has been available since the mid-to-late 1990's, and was certainly not Dr. Hsu's first cylindrical design to use extremely long ports.

That said, the term "turbo built-in" is really a misnomer. The idea behind our turbocharger technology is twofold: 1) the ability to lower the tune without adding to actual box length or floorspace occupied; 2) the ability to lower the tune without decreasing available port flow area. #1 is a huge improvement on the practical side, and #2 is a huge leap forward in variable tuning technology that Dr. Hsu helped pioneer many years ago in affordable box subwoofers with the VTF-2.

The inclusion of such technology in the popular box subwoofer is one reason why we have put development of the new TN-X cylinder on hold. The VTF-3HO has the potential to perform as well as DUAL TN1220HO's in the low bass. Even a single VTF-2HO has the potential to perform at or near the level of a TN1220HO in the low bass, which is impressive to say the least given the already very high performance of the TN1220HO.

Cheers

 

[shokhead]

No, Tom.... Not SVS specifically. There is more than one manufacturer making cylindrical enclosures for subs. Again, I feel that in the designs that I have seen, I just can't imagine how the "tube" enclosure, which in the cases I have seen are basically SOME FORM of paper composit (yes, that's rather simplistic.... but true all the same) covered in grill cloth.... or even "high tech" material of some kind..... can possibly be as expensive to produce as a heavilly braced, then finished MDF cabinet.

Of course, I don't build subs, so my thoughts and opinions are just that.... thoughts and opinions.

I didn't mean to dissrespect you or SVS in any way. I just remember how "STRONGLY" you folks seemed to be commited to cylinders in the beginning (when I first discovered SVS about three years ago) to now, where it seems that there is a new "box" design being introduced everytime you visit the site. Quite a departure from the original programming so to speak.

Of course, as Rob quite correctly pointed out, it may be SVS just catering to the demand for "box" style subs to meet market demand and retain share. That's just good business.

Maybe I was a bit over the top in my original comments, so for that I apologize.

I didnt know SVS should act any different then any other electronics maker{or any product} What ever they are putting out is IT,until the next IT. What should they say,well its not the best design but we are doing it anyway. No,it is the best design and thats why we are doing it. Why boxes, cant stay put or you'll fall behind and since there box subs gets just as good of reviews as the cyclinder, they must know what they are doing. Hell listen to me,i dont even have one. Cant rag on someone thats pushing there product,thats what makes the world go round. I would like to know how two equal subs,one box and one cyclinder would differ in sound? Eyes closed,could you tell?

 

[Fb111794]

I would like to know how two equal subs,one box and one cyclinder would differ in sound? Eyes closed,could you tell?

My first guess would be yes because it would be next to IMPOSSIBLE to get two that were exactly the same. Even if they were CLOSE and you discounted the differences, I think it would come down to which one then "looked" better.

Even then.... you would have most likely a 50/50 split or whatever the most current SVS/HSU mix is between their box and cylinder designs. As folks will differ on this as much as their preference for a particular sound.

Just my $.02, YMMV, FWIW, IMHO and all that....

 

[bray]

1 more ? Peter

Peter
Thanks for all the great info on the HSU upgrade!
One last question though.
Will this new upgrade to HO be easy for an average joe like myself to install?
Thanks

 

[Tom Vodhanel]

>>>That said, the term "turbo built-in" is really a misnomer. The idea behind our turbocharger technology is twofold: 1) the ability to lower the tune without adding to actual box length or floorspace occupied; 2)<<<

The DIYers have been guessing your are just going to offer a port extension...some sort of box that sits on the subwoofer box. So for example...on the VTF-3, you double the port length and instead of a single 3" port open in 20hz mode you have dual 3" ports open. So when you say "without adding to the box length"...you'll have another big box(or raw tubing) extending out and up a good deal...just put a big *U* on it and have all the extra piping extend over the top of the original unit? So if a current VTF-3 owner adds the extra piping...they will have dual 3" ports open in 20hz mode...which will work about the same as a single 4" port(when you consider the flaring on each).


>>>the ability to lower the tune without decreasing available port flow area. #1 is a huge improvement on the practical side, and #2 is a huge leap forward in variable tuning technology that Dr. Hsu helped pioneer many years ago in affordable box subwoofers with the VTF-2.<<<

The ability to lower the tune has been going on for about 60 years though...just lengthen the port..

Anyway...my original text about "turbo built in" was in reference to this comment you made...

"""So the VTF-3HO will have use of DUAL huge 4" ports in 18Hz tune with the turbo. We will also be offering a relatively low-cost upgrade option on current VTF-3 MKII, STF-3, and VTF-2 MKII subwoofers that should significantly improve performance, based on new technology that we are working on."""

Your comment about having "dual HUGE 4" ports with 18hz extension with the turbo...and this being something "new". My comment was...the SVS PB12-plus/2 has been in production for years...with this very feature. Which only proves our agreement on this matter...port area IS very important. Here is the quasi-anechoic data on the PB12-plus/2...

http://www.svsubwoofers.com/images/performancecharts/pb2plus.jpg

Dual 4" ports open(1 plugged) = +/-1.5dB from 18-150hz. In room...extension will be even deeper of course.

SVS has taken some heat in the past for designing enclosures with so MUCH port flow area...we have various designs that include three and even FOUR widely flared 4" ports. So it is great to see other manufacturers finally putting port flow capabilities in the forefront too..

Tom V.
SVS

 

[Tom Vodhanel]

>>>Two questions I have for either of you or anybody else that wants to chime in are:

1. What's the useful life of a subwoofer? I have a Mirage PS-12-90 that's almost 12 years old. I recently had it in the shop to repair a loose connection in the amp that was causing a hum. This has gotten me to think about upgrading my Mirage and I have been looking at both SVS and HSU.<<<

Hi Duff,

Most modern subwoofers should last for 5-10 years with no/little problems if you don't abuse them. Some folks like to open a new subwoofer and immediately run a 20hz sine wave thru it...for minutes at a time...ouch..


>>>2. How has the technology changed in sub design in the past twelve years. Besides having more power than my current sub what else should I be listening for?<<<

The primary changes have happened on three fronts.

1)the addition of the "tiny" subwoofer lines. Advancements in both driver excursion and amp power(from a given amp size) made it possible to produce bass from very small enclosures. Hoffman's Iron Law still holds true though..

2)the advancements in driver technology and amp technology(referenced above). Drivers now have much longer excursion capabilities and amplifiers can produce much more power for a given amplifier size.

3)The amount of LOUD, DEEP bass on common source material.

The introduction of the LFE channel on DVDs led to this to some degree. For example...10 years ago, before DVD...the "bassheads' were smiling when the VHS version of Jurassic Park included a nice 27hz T-Rex footstep.. Now, if an action oriented DVD doesn't include strong bass effects UNDER 20hz (and sometimes under 12-15hz!)...everyone seems to feel cheated.

And remember, many folks watch DVDs at/near reference level in their HTs. This can require extension down to the 12-15hz range...AND clean output capabilities in the 125dB range.(From the subwoofer, with all speakers set to small). Fortunately, these two extremes don't occur simultaneously..

Tom V.
SVS

 

[Duffinator]

Tom and Peter

Thank you both for your thorough answers to my questions. Looks like it's time to upgrade, now if I can decide on SVS or HSU I'll be set.

 

[Peter Marcks]

Hello again Tom

The DIYers have been guessing your are just going to offer a port extension...some sort of box that sits on the subwoofer box.

Just? This type of technology is certainly not trivial in advancing subwoofer practicality and performance, especially per given box size or per given floor space. Also, this is only one part of the patent-pending technology that will be featured on the VTF HO series.

The turbocharger box actually looks very clean and nice, and only moves up about half the length of the enclosure while being no more than 10 inches high. In my opinion, this is certainly much more preferrable than extending the entire box length by X number of inches in order to achieve the added port length. Those who have actually seen it in person have agreed. Also, this turbo unit is entirely optional. If a consumer is satisfied with performance and aesthetics without it, they will not need to use it.

So if a current VTF-3 owner adds the extra piping...they will have dual 3" ports open in 20hz mode...which will work about the same as a single 4" port(when you consider the flaring on each).

If I were you, I would not bother speculating yet on how much performance increase will be had on a VTF-3 MKII with the upgrade options. I suspect that many users will be quite pleased, but we have not finished working on the new technology yet for these existing VTF-2 MKII and up subwoofers.

The bottom line is that any type of performance-enhancing upgrade option that is available for a relatively low price is always a good thing. Period.

The ability to lower the tune has been going on for about 60 years though...just lengthen the port..

These traditional solutions required the designer to actually significantly increase the box or cylinder length. More recent variable tuning solutions since the mid-90's (with the inception of the VTF-2) allow one to lower the tune without increasing box length, but the fundamental drawback is that port flow area needs to be reduced each time the tune is lowered. The new variable tuning technology that we are working on is a huge advancement in this arena.

Your comment about having "dual HUGE 4" ports with 18hz extension with the turbo...and this being something "new". My comment was...the SVS PB12-plus/2 has been in production for years...with this very feature.

I do not follow this line of logic. Quite obviously, having dual "HUGE" 4" ports in 18Hz tune is not a novel thing, and I never mentioned as such. The TN1220HO in pairs will have dual 4" ports in 18Hz tune, and has been around since the mid-to-late 1990's.

Which only proves our agreement on this matter...port area IS very important.

We do believe that port flow area is important, but at the same time, we also believe in maximizing bass per given box size and per given floor space. The turbocharger is a great way to do this, without question.

Cheers

 

[furrycute]

I have a question for both the Hsu and the SVS reps. BTW, thank you both for your helpful contributions!

Why doesn't Hsu or SVS build sealed subs? I am mainly interested in music playback, and I have read that sealed designs offer quicker and cleaner bass response compared to ported designs.

This is the reason why I have been thinking about the Velodynes and Rels, both of which are sealed designs.

 

[Rock&Roll Ninja]

Does anyone have any pictures (or links to pictures) of the "Turbo" units?

 

[Peter Marcks]

Dear furrycute,

The VTF HO models will have the ability to be run either as ported or sealed subwoofer systems. Still, they are not ready yet, with availability estimated towards closer to summer.

Sincerely,

 

[Tom Vodhanel]

>>>The turbocharger box actually looks very clean and nice, and only moves up about half the length of the enclosure while being no more than 10 inches high. In my opinion, this is certainly much more preferrable than extending the entire box length by X number of inches in order to achieve the added port length.<<<


Well, as you always say...tradeoffs. When you make the enclosure larger...not only can you fit the proper porting in the enclosure to begin with...but you gain system efficiency and sensitivity. That is Hoffman's Iron Law...no way around that. Each manufacturer will have to determine how much performance they are willing to sacrifice regarding ultimate box size. If you make the enclosure larger to begin with(so it has the proper porting for the application)...not only do you benefit from the increased port flow...you also gain system sensitivity because of the Iron Law I referred to earlier. But the enclosure will be slightly larger...and thus the WAF may drop...tradeoffs..




Quote:
So if a current VTF-3 owner adds the extra piping...they will have dual 3" ports open in 20hz mode...which will work about the same as a single 4" port(when you consider the flaring on each).



>>>If I were you, I would not bother speculating yet on how much performance increase will be had on a VTF-3 MKII with the upgrade options. I suspect that many users will be quite pleased, but we have not finished working on the new technology yet for these existing VTF-2 MKII and up subwoofers.<<<


I wasn't speculating on performance, I was referring to the area increase of the porting. Going from a single 3" port to duals will definitely add to the clean output of your unit. But as I'm sure you know, the porting really only factors in around the tuning point of the enclosure. For example, with an 18hz tuning point...adding port area won't be of any benefit over the vast majority of the operating range of a subwoofer(if we consider that say...18-150hz in this example). You'll gain a bit <22-24hz...but >24-25hz...port area won't be much of a factor(because there will be no/very little air flow thru the port(s) to begin with).







Quote:
The ability to lower the tune has been going on for about 60 years though...just lengthen the port..



>>>These traditional solutions required the designer to actually significantly increase the box or cylinder length. More recent variable tuning solutions since the mid-90's (with the inception of the VTF-2) allow one to lower the tune without increasing box length, but the fundamental drawback is that port flow area needs to be reduced each time the tune is lowered. The new variable tuning technology that we are working on is a huge advancement in this arena.<<<


Well, I guess it all comes down to semantics to some degree. You say the "old" way required a larger enclosure...but the "new" way will increase the overall size of the subwoofer to approzimately the same degree wouldn't it? And the old way also had benefits due to the Iron Law I referenced above.


Quote:
Your comment about having "dual HUGE 4" ports with 18hz extension with the turbo...and this being something "new". My comment was...the SVS PB12-plus/2 has been in production for years...with this very feature.



>>>I do not follow this line of logic. Quite obviously, having dual "HUGE" 4" ports in 18Hz tune is not a novel thing, and I never mentioned as such. The TN1220HO in pairs will have dual 4" ports in 18Hz tune, and has been around since the mid-to-late 1990's.<<<


I was referring to variable extension box enclosures. Our 25-31cs in "quads" will have FOUR 4" flared ports...but that really isn't what I meant..


Tom V.
SVS

 

[Tom Vodhanel]

>>>Why doesn't Hsu or SVS build sealed subs? I am mainly interested in music playback, and I have read that sealed designs offer quicker and cleaner bass response compared to ported designs.<<<

Hi furrycat,

We've been building sealed proto types for over 5 years now. In our tests, the sealed designs give up to much deep bass performance to meet our cost/performance goals. Many commerical sealed units actually rolloff a good deal in the 30-35hz range. This isn't always a bad thing, as some folks prefer that. Remember, the deeper the bass, the longer the sound wave. The longer the sound wave, the more time it will take to decay in a room. So a subwoofer that attenuates the deepest bass will often sound "quicker" to some listeners. In smaller rooms, an attenuation <35hz or so can work out okay...as "room gain" will tend to add back to that...and give you relatively flat output. We've had quite a few SVS owners in very small rooms plug all the ports on our subwoofers with good results. But unless you are in a very small room(with no large openings to other areas of the home)...we really don't recomment that.

Tom V.
SVS

 

[Rob Babcock]

No need for this to become a fight, guys. Hsu & SVS both make good subs and either would be an excellent choice. Please confine your comments to the merits of your own products as opposed to the "failings" you perceive in the other guys.

 

[Peter Marcks]

Again, Tom?

If you make the enclosure larger to begin with(so it has the proper porting for the application)...not only do you benefit from the increased port flow...you also gain system sensitivity because of the Iron Law I referred to earlier. But the enclosure will be slightly larger...and thus the WAF may drop...tradeoffs.

There is no such thing as "proper porting" for an application. Rather, historically, box length has limited a designer in how long a port that can be used in a ported subwoofer design. The new technology we are working on helps to break these barriers.

If one wanted to create a box subwoofer to house the port in the TN1220HO, the box would need to be in excess of 30 (!) inches long. The VTF HO ports with turbo extension will obviously be even longer than that in total. Sure, someone could design a box subwoofer to house super long ports and gain some efficiency with the larger box, but this is just not practical for the vast majority of consumers. In realistic terms, a commercial designer can only go so far with respect to box length.

I wasn't speculating on performance, I was referring to the area increase of the porting. Going from a single 3" port to duals will definitely add to the clean output of your unit. But as I'm sure you know, the porting really only factors in around the tuning point of the enclosure.

The ultra low bass is the most important area where the VTF-3 MKII could use a performance enhancing option. Clean output in the most common bass frequencies greater than 22Hz is naturally much higher in comparison to the lower frequency output.

Well, I guess it all comes down to semantics to some degree. You say the "old" way required a larger enclosure...but the "new" way will increase the overall size of the subwoofer to approzimately the same degree wouldn't it?

I do not follow this mathematics. If a turbocharging unit adds X inches of port length, while only taking up half the length of the enclosure and having no more than 10 inches of height, how does that give equal box size vs extending the length of the entire box by X inches? Especially when you are talking about large box subwoofers with at least 22-28 inches of height, extending the length of the box results in a MUCH bigger overall box size vs simply adding a turbo unit. Floorspace is also obviously compromised in a major way too. And with respect to efficiency from larger box size, as I mentioned before, it is just not practical for most commercial designers to use such a large box.

I was referring to variable extension box enclosures.

I am not aware of any commercial box subwoofer with less than or equal to two drivers that is tuned below 18Hz with use of dual 4" ports. It hardly matters though, as novelty of dual 4" ports is a moot point.

 

[Peter Marcks]

Dear Rob,

Thank you for helping to control things here. I think it should be clear to most that Dr. Hsu is genuinely trying to advance ported subwoofer technology in a good way with ideas such as a turbocharger option that boosts low bass performance without compromising floorspace and without reducing port flow area. The last thing anyone should be doing is attempting to trivialize this feat.

Sincerely,

 

[shokhead]

I find all of this interesting but abit over my head so i hope i dont trivialize it but turbo charger option that boosts low bass seems like something from Mattel.

 

[Tdekany]

I realize that this is my first post on this forum - so I will try to be as politically correct as I can be:

Seeing Tom Vodhanel responses to Peter's is one of the most unprofessional behavior I have ever seen from a manufacturer.

 

[MDS]

Seeing Tom Vodhanel responses to Peter's is one of the most unprofessional behavior I have ever seen from a manufacturer.

Really? I think they were both very civil and I learned a few things from the discussion. If it had disintegrated into the kinds of flames you usually see when discussing unproven tweaks and bogus pseudo-scientific claims, I would agree with you - but they weren't discussing those things. They were discussing the slightly different design philosophies of their respective companies, it was informative, and it didn't degrade to a flame fest.