# Subsonic subs for real?



## Cherrylime (Jun 17, 2012)

I just saw a pair of one-off Goldmund subs (I believe they are the Logos 3A infra-subwoofer) that have a claimed bandwidth of 10hz to 20hz. Enclosures are all aluminum, weigh about 700 lbs, 5ft. high, about 22 inches width and 17 inches deep. the only opening is a single 5 inch port in the chamber the driver fires into. The front and rear chamber seem to be of equal size. One driver per cabinet, a 15 inch JBL 2226H 8 ohm. I have yet to hear these monsters. I was told I would feel them more than hear them.
I find it hard to believe these JBLs will perform so low. I am no scientist so I was wondering if anyone had any thoughts on how these things might work and how they might be integrated into a home theater setup.

Jim


----------



## tonyvdb (Sep 5, 2007)

10Hz is achievable, There are many subs that go that deep out there. The SVS PB13U will hit 10Hz The PSA T-18 will hit 9Hz and there are a number of others that also will.


----------



## Talley (Dec 8, 2010)

I love how it's a -10db rating.

Seriously... there is no replacement for displacement. displacement = driver size and excursion capability.

now someone will come along and tell me I'm wrong.

Dual 24s > *


----------



## Chromejob (Feb 19, 2015)

My Hsu VTF -2 seems to go down to 18 or 16 in my home. Does anyone NEED 10Hz?


----------



## tonyvdb (Sep 5, 2007)

"need 10Hz" no but there are movies that have information that goes that low. In the real word there are plenty of sounds that dig that deep.


----------



## vidiot33 (Dec 12, 2013)

Even those that can go that low are likely to be be down significantly and there's also the matter of very little content, as has been mentioned, and price. I remember years ago reading a review of "Apocalypse Now" where the reviewer mentioned that you would not want to hear the real world depth and volume that was produced by the weapons in the movie, as it would likely cause hearing damage. I don't believe any of us wants that!


----------



## Lumen (May 17, 2014)

tonyvdb said:


> 10Hz is achievable, There are many subs that go that deep out there. The SVS PB13U will hit 10Hz The PSA T-18 will hit 9Hz and there are a number of others that also will.


I take it they're not a solution looking for a problem. Top-notch encoding formats must have content that low for these subs to be worthwhile, right? I mean, they don't use subharmonic synthesis of source material to work, right? I realize that not every film will have suitable LFE content, but how low does the industry spec generally go for True HD or HD Master quality?


----------



## willis7469 (Jan 31, 2014)

I believe the spec for the LFE channel is 3-120hz


----------



## Mike0206 (Jul 14, 2013)

My subs can dig down to 5hz pretty easy but your in danger of over excursion at that point as I found out. They will do 100db at 5hz in my big room but that's with REW frequency sweeps. My subs are 2 FTW-21's in ~8 cu ft boxes and in a very large room of 7500cu ft and they still over power it. However only a couple of movies can even give the subs a work out and there is a scene in the first Hulk movie that has some low frequencies in it. Someone did a RTA of the scene and they measured down to 5 hz for a significant amount of time but I don't know many other movies aside from maybe WOTW that has content that low.

EDIT: Just for emphasis sake when I run the sweeps through REW my house shakes, windows rattle and literally make the glass look like it's warping before you hear anything from the subs. They are moving a lot but no audible noise just a whoosh from the driver pushing so much air. It's not until it hits around 17-20hz that you start to hear the actual frequency noise. It honestly feels like an earthquake is about to hit cause everything in the house is shaking and moving and you can't hear anything. By the way I'm in California and have a fairly new house on a concrete foundation and it feels like the walls are gonna cave in. It's Awesome!!!!


----------



## willis7469 (Jan 31, 2014)

I think data-bass.com has a bunch of spectrographs. Good stuff!


----------



## Talley (Dec 8, 2010)

How to train a dragon has a scene thats some 4hz commanding 117db or something like that.

My single 15" HSU can handle down to 12hz at -3db. Although I think the cannon scene in "9" destroyed the sub...


----------



## tonyvdb (Sep 5, 2007)

The Hulk "sonic cannons" scene has LFE down to below 10Hz


----------



## Cherrylime (Jun 17, 2012)

Thanks for the feedback. I guess my question is how do they get a driver that performs down to 30hz to operate in the 10 to 20hz range. Also, how would I integrate such a thing into my system? What would be needed amp-wise to function at those low frequencies and how would you crossover? The lowest crossover point on my processor is 50 hz. My full range speakers perform well down to the 20 - 25hz range.

Jim


----------



## tonyvdb (Sep 5, 2007)

It has a lot to do with the box size, the bigger the deeper it "can" go if the driver is able to move enough air.

Crossover settings is a setting where your mains start getting LFE and where the sub stops ( these are not a birck wall but rather a slope.
How deep a sub will go will also depend on the high pass filter. This is much more a brick wall in the sense that anything below the set HPF will not go to the sub (for example anything below 10hz) if the driver gets anything below this setting and it's not designed for it you will literally tear it apart if driven hard.

What speakers do you use for your mains. There are very few speakers that can go down to 25hz at any real usable levels.


----------



## willis7469 (Jan 31, 2014)

Cherrylime said:


> Thanks for the feedback. I guess my question is how do they get a driver that performs down to 30hz to operate in the 10 to 20hz range. Jim


 I wonder this too.


----------



## Talley (Dec 8, 2010)

tonyvdb said:


> What speakers do you use for your mains. There are very few speakers that can go down to 25hz at any real usable levels.


SVS Ultras hit down to 25 in my room. I have to tame these bad boys back... still trying to get them tamed.


----------



## tonyvdb (Sep 5, 2007)

I can promiss you that they are working hard to hit those frequencies. My EVs are already working hard at those frequencies and are flat to 30hz


----------



## jb5200 (Aug 20, 2010)

I have 2x TC Sounds LMS Ultra's and always wondered how low they go, for a lot of the music they are just too deep (sound seems artificial and boomy) but for movies I can't imagine anything more than that!


----------



## atledreier (Mar 2, 2007)

My IB sub can also hit 10Hz with gusto. My foundations hate it every time, though. 

Do I need it? Not really. Is it cool that it CAN? Sure! :hsd:


----------



## Talley (Dec 8, 2010)

tonyvdb said:


> I can promiss you that they are working hard to hit those frequencies. My EVs are already working hard at those frequencies and are flat to 30hz


I don't see how or why. They are rated to 28hz factory. I'm assuming I have some room gain to support to 25.


----------



## tonyvdb (Sep 5, 2007)

Just because the specifications say it can go down to 28Hz does not mean that it can at any real usable levels. When you start to go below 30Hz it takes alot more cone movement to produce those frequencies and this movement not only takes alot of power but it also causes heat buildup in the motor. This is why most of us use subs and set a crossover at around 80Hz.
I can assure you that if you try to run content with 25Hz through those speakers it will be far lower output than any decent sub will do. You will be lucky if its at 65db at 25Hz


----------



## Cherrylime (Jun 17, 2012)

I have a pair of AvanteGarde Trioo with a pair of Basshorns


----------



## tonyvdb (Sep 5, 2007)

Cherrylime said:


> I have a pair of AvanteGarde Trioo with a pair of Basshorns


Nice!
:TT :TT


----------



## Cherrylime (Jun 17, 2012)

I posted too quick. Avantgarde Trios and Basshorns as my mains. Center channel is an Avantgarde Solo with an Avantgarde 230 bass cabinet. Surrounds are Avantgarde Solos, each with an Avantgarde 225 Bass cabinet


----------



## Talley (Dec 8, 2010)

tonyvdb said:


> Just because the specifications say it can go down to 28Hz does not mean that it can at any real usable levels. When you start to go below 30Hz it takes alot more cone movement to produce those frequencies and this movement not only takes alot of power but it also causes heat buildup in the motor. This is why most of us use subs and set a crossover at around 80Hz.
> I can assure you that if you try to run content with 25Hz through those speakers it will be far lower output than any decent sub will do. You will be lucky if its at 65db at 25Hz


Maybe it's the krell then? :rofl:

I'll test it out again tonight... I've played some music and have not had any issues with the speakers in direct mode yet. They have handled some low playing music. Norah Jones - Sunrise is a song with content down into the low 20s and to be honest it sounds better without the sub.... just hard to tame these speakers back as they are a tad bass heavy.

My uncle says that it's because I'm running 10awg speaker cable thats 7' long to my mains. Says the larger the cable the more emphasis on the bass it will have and less on the highs. Says I need to test some 12awg and even some 14awg considering the speakers play low decent.


----------



## tonyvdb (Sep 5, 2007)

Cherrylime said:


> I posted too quick. Avantgarde Trios and Basshorns as my mains. Center channel is an Avantgarde Solo with an Avantgarde 230 bass cabinet. Surrounds are Avantgarde Solos, each with an Avantgarde 225 Bass cabinet


For music listening those speakers are just fine and your not likely missing anything in the subsonic range but with movies then a good sub would be really advantages for you. You would wonder why you did not get one sooner.


----------



## Talley (Dec 8, 2010)

tonyvdb said:


> For music listening those speakers are just fine and your not likely missing anything in the subsonic range but with movies then a good sub would be really advantages for you. You would wonder why you did not get one sooner.


Exactly. Movies = as many subs you can afford, as large as possible, as much power as possible lol


----------



## Chromejob (Feb 19, 2015)

Talley said:


> How to train a dragon has a scene thats some 4hz commanding 117db or something like that....


OOH, I have that. D'ya know what scene? 



Cherrylime said:


> Thanks for the feedback. I guess my question is how do they get a driver that performs down to 30hz to operate in the 10 to 20hz range. Also, how would I integrate such a thing into my system? What would be needed amp-wise to function at those low frequencies and how would you crossover? The lowest crossover point on my processor is 50 hz. My full range speakers perform well down to the 20 - 25hz range.
> 
> Jim


Before buying, I bought an online subscription to Widescreen Review so I could download Richard Hardesty's series on Subwoofer Fundamentals. Worth the $. Learned a lot. He mentioned that room acoustics and positioning makes a HUGE difference in performance of a sub. He also goes into music theory and frequencies to identify what, if any, music will go that low. Pipe organs can. In fact, my Hsu test CD has an excerpt from Saint-Saen's Organ Symphony recorded in a hall in NH, the pipe goes down to 16hz, and the recording engineer confirmed that the track has some of the cleanest naturally occurring 16Hz he's heard. Sure enough ... my VTF-2 works that, somewhat. 

He recommends a crossover at 80Hz in the AVR, I guess that's a THX standard, but you CAN deviate. I have mine higher due to the bass response of my Bose 401s. They go down to 40Hz-ish, but not consistently. In fact, there's a little dip around 130Hz, too. 

My Yamaha RX-V775 allows a sub cross over in bass management from 40Hz to 200Hz. It can also direct the bass to the mains as well as the sub, I don't do that. Hardesty does recommend having mains that can handle the lower freqs, and as an option letting them go down below the cross over. E.g. if I had SVS Ultra Towers, I might do that. 



jb5200 said:


> I have 2x TC Sounds LMS Ultra's and always wondered how low they go, for a lot of the music they are just too deep (sound seems artificial and boomy) but for movies I can't imagine anything more than that!


If the subs are doing anything in music where there just isn't that low a frequency, something's wrong. Artificial and boomy during music is a big tip-off for me. 

You can download sound files from audiocheck.net to determine just how low they can play. Put 'em on an iPod or CD, and there you go. I used their sweeps (as well as Hsu's test CD) to find the weakness around 130Hz in my mains, and set the AVR cross over point.



Talley said:


> Maybe it's the krell then? :rofl:


Haha, that reminds me to go get my *Forbidden Planet* BD, I wonder if there's some good LFE in there, perhaps in the climax. 



Talley said:


> ... I'll test it out again tonight... I've played some music and have not had any issues with the speakers in direct mode yet. They have handled some low playing music. Norah Jones - Sunrise is a song with content down into the low 20s and to be honest it sounds better without the sub.... just hard to tame these speakers back as they are a tad bass heavy.
> 
> My uncle says that it's because I'm running 10awg speaker cable thats 7' long to my mains. Says the larger the cable the more emphasis on the bass it will have and less on the highs. Says I need to test some 12awg and even some 14awg considering the speakers play low decent.


I'm skeptical, but ... well maybe. I wonder how that effects line level coax cables to a power sub...? I didn't get a fancy one, but I did notice a slight difference from a lower end 6' Belkin cable to a 15' MediaBridge cable. Might upgrade to a Blue Jeans or Monoprice cable now that I know where my sub will homestead. 



Talley said:


> Exactly. Movies = as many subs you can afford, as large as possible, as much power as possible lol


LOL I'm not that fond of thundering lows, but watching *Earth to Echo* last night, I was pleased at some mild, fleeting LFE during a couple of scenes. I think some film sound editors throw in some LFE "just because" without really thinking it through. The silent propulsion in *Hunt For Red October*? Hellyeah. A car engine rolling by in a street scene? Maybe. A tonal flourish when we see the bank vault door (not doing nuthin') in *The Dark Knight*'s opening heist? Puh-leaze, no. (Actually it might be the music score that's doing that. But still, it was a bit much. "Okay, I see the bank vault. I don't need a big, thudding 'ta-da!' to emphasize it....")


----------



## atledreier (Mar 2, 2007)

Some stereo music recordings can get alot better with a well integrated subwoofer. The sense of space in a large recording venue can often only be reproduced by a really good sub. When I installed my IB a lot of recordings got a "second life".


----------



## Talley (Dec 8, 2010)

tonyvdb said:


> Just because the specifications say it can go down to 28Hz does not mean that it can at any real usable levels. When you start to go below 30Hz it takes alot more cone movement to produce those frequencies and this movement not only takes alot of power but it also causes heat buildup in the motor. This is why most of us use subs and set a crossover at around 80Hz.
> I can assure you that if you try to run content with 25Hz through those speakers it will be far lower output than any decent sub will do. You will be lucky if its at 65db at 25Hz



went through all my notes and here was some back to back testing I did back to back on the 9th. What I did was ran audyssey with the sub removed... I was trying to see what it could do with just the mains and this was my results:

now... I have no idea how much boosting is going on down low but they sound much better after audyssey is ran and removing the ports I really should of reran the audyssey to see if it would tame it back down but I don't plan on running ported on the Ultras so I didn't bother with it. I'm pretty sure I ran the test with the volume setup with the pink noise on my SPL meter was reading 80db.

I need to retest this in direct mode sealed and direct mode ported. I'm pretty sure the Ultra is rated 28hz in ported mode.


----------



## rhsmith42 (Jan 3, 2014)

Ultra low end is awesome if done right.. but aside from a small amount of the total movie sources available having content below 25Hz, the stuff that does can wreck your house if you have the right hardware.. I have a 2100 cu.ft. theater room with well managed acoustics with a Yamaha RX-V863 driving 2 Accuphase P-300's (modified - [email protected] without limiters and bandpass modules) into DIY Morel/Dynaudio for the L/R/C channels and the Yamaha is directly driving some Polk surround/rears and 6 NHT 1259 (in 2.5 cu.ft.sealed boxes) DIY subs and I am driving them with 3 (again modified no limiters) Hafler D500 power amps from 80Hz on down. I have measured SPL of 115db at 15Hz and there was more to go but things started falling off walls all around the house and I had to stop testing.. My wife was not a very happy camper as I did not warn her I was going to do some testing and she thought something horrible was happening to the world around her. Transient performance and crushing bottom end from movies like WOTW and Transformers 2/3 are scary impressive with that kind of power in the room.. WAY better than any Imax theater..


----------



## willis7469 (Jan 31, 2014)

Had to say, 1) awesome. 2) I am laughing hysterically at the idea of your wife running around trying to figure out what was happening to her house.


----------



## Chromejob (Feb 19, 2015)

"Honey, I need to move the house about 3" to the right to make room in the rose garden. You'll feel a little shuddering.... L'tell you when I'm done!" 

(Like when Howl reconfigures the castle in *Howl's Moving Castle*.)



atledreier said:


> Some stereo music recordings can get alot better with a well integrated subwoofer. The sense of space in a large recording venue can often only be reproduced by a really good sub. When I installed my IB a lot of recordings got a "second life".


Indeed. I'm playing Diana Krall's "Between the Devil And the Deep Blue Sea" (_Stepping out_), and the drum set sounds just a wee bit better with a powerful sub taking the bottom 120 hertzes.


----------



## Talley (Dec 8, 2010)

tonyvdb said:


> Just because the specifications say it can go down to 28Hz does not mean that it can at any real usable levels. When you start to go below 30Hz it takes alot more cone movement to produce those frequencies and this movement not only takes alot of power but it also causes heat buildup in the motor. This is why most of us use subs and set a crossover at around 80Hz.
> I can assure you that if you try to run content with 25Hz through those speakers it will be far lower output than any decent sub will do. You will be lucky if its at 65db at 25Hz


OK I went through and reran audyssey and this is the results with 2 channel only. The SVS ultra towers.

Seems like 25hz is a pretty good measurement with the Ultra Towers only. I ran the test 20-20k.

My uncle told me for music there is no need for a sub with my setup or for 98% of the music out there.


----------



## Chromejob (Feb 19, 2015)

Talley said:


> OK I went through and reran audyssey and this is the results with 2 channel only. The SVS ultra towers.
> 
> Seems like 25hz is a pretty good measurement with the Ultra Towers only. I ran the test 20-20k.
> 
> My uncle told me for music there is no need for a sub with my setup or for 98% of the music out there.


Wowzers. I'm definitely keeping the SVS Ultra Towers on my Christmas wish list.... BUT. If the test is playing singular tones at a specific time, the graph you got could be very different if the speakers are loaded up with a variety of frequencies at one time. 

Some reading I did on the impedance switches in AVRs mentioned that some speakers have lower impedance at lower freqs, so amps may do more "heavy lifting" (greater power, greater heat) to drive them at the lower freqs. So even with speakers that CAN go that low, might not be doing your AVR a favor to ask it to drive that low. 

On. The. Other. Hand. ... Some engineers (I've been reading Richard Hardesty's guides at Widescreen Revier) recommend using a sub even with speakers that can down low, with some overlap; the sub doesn't have to be so loud. My Yamaha amp can optionally send the bass below the base mgmt cross over point to the mains _anyway_ for those that can. Called Extra Bass Tried it with my Bose 401s, wasn't very satisfying (no surprise). 

As for music, I concur with your uncle, but lately have been listening to some stuff that indeed does benefit from a sub. Saint-Saens' Symphony #3 (organ symph), second movement, *of course* (the organ will play notes with potential subharmonics down to 16Hz). Holly Cole "Train Song" (_Temptation_), Chris Isaak "Dancin'" (_Baja Sessions_), Viva Voce "Good as Gold" (_Rose City_), Alison Krauss/Robert Plant "Rich Woman" (_Raising Sand_), Ladysmith Black Mambazo "Wawusho Kubani?" (_Shaka Zulu_), James Newton Howard "Matobo" (_The Interpreter OST_; REALLY good!), Diana Krall "Between the Devil and the Deep Blue Sea" (_Stepping Out_, the drummer gets a lot of up front time on the entire album), Linkin Park "Frgt/10" (_Reanimation (DMD Album for all MSPs)_).[1] A composer friend of mine told me years ago that he has 30Hz, 35Hz tone in the close of his album _Stalker_ (Robert Rich/B. Lustmord, "A Point of No Return"). 

I have my cross over set high in the AVR due to the mains having a dip at about 130Hz, and relatively haphazard bass < 90Hz. Different genres of music definitely benefit from a really capable (i.e. imperceptible due to strength and stability) sub. 

[1] I got some of these suggestions from audiophile reviewers' lists of "speaker test tracks" at various places. Some are from my own library.


----------



## tonyvdb (Sep 5, 2007)

Talley, what mic are you using for those measurements?


----------



## willis7469 (Jan 31, 2014)

I have to agree with chromejob. Over the years I've used "direct" off/on and I always end up back with stereo/PLII music. My mains are rated to 35hz, so they're plenty solid. For me, the problem is despite being "accurate", direct is just too stale. Go down to even some local dive ****** tonk, (bar) and you'll notice palpable bass, from even the most meager bass rig. As mentioned, venues themselves contribute to sub harmonics that just translate better through subs. I guess what I mean is, having been involved with, and around live music, direct mode just ain't right. IMO. I do listen to classical guitar, and this is one place I like direct mode. I tried my dubstep station (pandora) in direct. Rofl...


----------



## Chromejob (Feb 19, 2015)

Well, my mains have tuned ports at the rear for the lower register (from a chamber fed by the dual woofers I think). SVS Primes have two rear-firing ports. The SVS Ultras have a single rear-firing port in addition to side-firing woofers (from what I can see in their pics). 

So some speakers use the back or side wall to reinforce bass just as subwoofers do. It can still come down to _speaker efficiency_ (power, fidelity) and AVR capability. Maybe that's something that bi-amp configuration helps with.


----------



## willis7469 (Jan 31, 2014)

Well, biamping is mostly considered useless. As far as the ports facing the wall, the only thing that does is enforce the extension that the drivers/cab can produce. Stuffing a speaker in the corner that rolls off at 60hz for example, won't make it play 40.


----------



## Talley (Dec 8, 2010)

tonyvdb said:


> Talley, what mic are you using for those measurements?


Calibrated Umik-1 from cross spectrum using HDMI and asio from my laptop



Chromejob said:


> Well, my mains have tuned ports at the rear for the lower register (from a chamber fed by the dual woofers I think). SVS Primes have two rear-firing ports. The SVS Ultras have a single rear-firing port in addition to side-firing woofers (from what I can see in their pics).


Yes my Ultras have a single port in the back... but I run it sealed. The foam is inserted and the results in the graph I posted above are SEALED. If you would like I can run the tests again ported.



willis7469 said:


> Well, biamping is mostly considered useless. As far as the ports facing the wall, the only thing that does is enforce the extension that the drivers/cab can produce. Stuffing a speaker in the corner that rolls off at 60hz for example, won't make it play 40.


Right. Also my test is after I moved the speakers away from the wall about 2' from the back wall and 5' from the side wall, remember I'm setup backward in my room (screen and LP along the long walls)


----------



## Talley (Dec 8, 2010)

Chromejob said:


> Some reading I did on the impedance switches in AVRs mentioned that some speakers have lower impedance at lower freqs, so amps may do more "heavy lifting" (greater power, greater heat) to drive them at the lower freqs. So even with speakers that CAN go that low, might not be doing your AVR a favor to ask it to drive that low.


Good point. I'm not using an AVR though I'm using the AVR as a pre/pro only and my Krell is handling the load. I still want to test something with more grunt behind it like a Emotiva 400w/channel amp and see if I see any improvements.


----------

