Wow this thread has really stirred up a hornets nest.
In the interest of your neighbours living in a flat or house.
10hz-20hz travels it travels through everything. I like to think of it as sub sonic noise pollution, wasted energy etc, if your listening room is not sound proof/ acoustically dead enough there will be problems, nothing is worse than listening to walls buzzing, glasses rattling etc.
it really kills the whole home cinema expearience.
i have been looking at this thread and agree that home cinema really rocks if you have a sub that goes down to 20-25hz.
10-25hz is questionable and how many decoders in the real world reproduce these frequencies?
Go with a couple of cheap 15' of a single 18' front loaded in a reflex enclosure. and if its -3db response falls around 25hz it is undoubtable the sub will go below20hz at -6db
This is the question i think needs to be asked does hi fi system/ home theatre system need a flat frequency response to 10/25hz
In the interest of your neighbours living in a flat or house.
10hz-20hz travels it travels through everything. I like to think of it as sub sonic noise pollution, wasted energy etc, if your listening room is not sound proof/ acoustically dead enough there will be problems, nothing is worse than listening to walls buzzing, glasses rattling etc.
it really kills the whole home cinema expearience.
i have been looking at this thread and agree that home cinema really rocks if you have a sub that goes down to 20-25hz.
10-25hz is questionable and how many decoders in the real world reproduce these frequencies?
Go with a couple of cheap 15' of a single 18' front loaded in a reflex enclosure. and if its -3db response falls around 25hz it is undoubtable the sub will go below20hz at -6db
This is the question i think needs to be asked does hi fi system/ home theatre system need a flat frequency response to 10/25hz
timothyldodd said:
It wasn't until I got my dual 12" Dayton's that I understood that I had a 35hz resonance problem with my television.
I've heard glass vibration problems in other houses.
I wonder how effectively you could create a notch filter with such a sharp Q that you could get rid of a few problem areas?
Flat frequency response of the driver or the room? I've EQ'd my room digitally and the results were mixed. On the one hand, it seemed like I could pick out details better. No single frequency overwhelmed the others. But it also sounded "processed".
Now a 24db/LR crossover has its own sound, but I find that the processing doesn't bother me as much as EQ'ing bass. Go figure!
I don't know if 10-25Hz is necessary, but I believe it is important. Even playing acoustic guitar music, you get added 'stuff' that you don't get without this area (esp. if you have someone who uses the guitar body as percussion). Ok, it's not as if it won't sound good without - just that it sounds better with. Probably doesn't need to be down to 10Hz... 
And flat is an interesting concept. You definitely don't need a system that plays flat to 10Hz anechoically. And you probably don't need one that even plays flat to 10Hz "in room" (that mysterious room again!). But there is information in DVDs and some CDs that can be felt in the seat of your pants (below 16-20Hz).
And, if you are loading your room up to be playing those low notes, you will need to fix your room up so that it doesn't rattle 'n' hum. I hear it all the time in cars - there's that one note bass and all you can hear is the boot ("trunk" for those in the Americas) rattling along. And I've have the same problem at home. But not at the moment, than goodness.
Daveis, I think you'd be looking at maybe 4 12" or 15" in sealed container, with lots of amplification. You could probably get a good set-up from Rythmik, which would include a Linkwitz transform. But you'd be up for close on $1000 if you do your own woodwork.
And flat is an interesting concept. You definitely don't need a system that plays flat to 10Hz anechoically. And you probably don't need one that even plays flat to 10Hz "in room" (that mysterious room again!). But there is information in DVDs and some CDs that can be felt in the seat of your pants (below 16-20Hz).
And, if you are loading your room up to be playing those low notes, you will need to fix your room up so that it doesn't rattle 'n' hum. I hear it all the time in cars - there's that one note bass and all you can hear is the boot ("trunk" for those in the Americas) rattling along. And I've have the same problem at home. But not at the moment, than goodness.
Daveis, I think you'd be looking at maybe 4 12" or 15" in sealed container, with lots of amplification. You could probably get a good set-up from Rythmik, which would include a Linkwitz transform. But you'd be up for close on $1000 if you do your own woodwork.
timothyldodd said:Wow this thread has really stirred up a hornets nest.
In the interest of your neighbours living in a flat or house.
10hz-20hz travels it travels through everything. I like to think of it as sub sonic noise pollution, wasted energy etc, if your listening room is not sound proof/ acoustically dead enough there will be problems, nothing is worse than listening to walls buzzing, glasses rattling etc.
it really kills the whole home cinema expearience.
i have been looking at this thread and agree that home cinema really rocks if you have a sub that goes down to 20-25hz.
10-25hz is questionable and how many decoders in the real world reproduce these frequencies?
Go with a couple of cheap 15' of a single 18' front loaded in a reflex enclosure. and if its -3db response falls around 25hz it is undoubtable the sub will go below20hz at -6db
This is the question i think needs to be asked does hi fi system/ home theatre system need a flat frequency response to 10/25hz
Simple fix would be to stop things in your house from rattling.
If you live in a flat (appartment), you shouldn't be playing your system that loud to begin with. Also, with bass that low, nobody would know where it's coming from anyway.
Most modern decoders/receivers can play down to about 7Hz, some to 10Hz. Same thing is true for most modern amps these days. BTW, these are all in the "real world".
Lastly, you don't use a couple of "cheap" 15" or 18" drivers unles you want CHEAP sound. If you are willing to use cheap drivers, you are also willing to use cheap amplification and everything else, which means you're most likely not very interested in quality sound. So in that case, I guess it doesn't matter what drivers you use.
Also, a system that is tuned "flat" in a room typically sounds lifeless, dry, probably very bass heavy and overall boring.
Speaking of "tricks". Sometimes we can't get our dog to come in the house as he would rather stand and bark at neighbors. But he is very much afraid of thunder. So I play this uncompressed recording of fireworks (that I got from this forum) and he heads straight for the door!
Doesn't even have to be very loud.
Doesn't even have to be very loud.
chops said:
Well, that depends. What if you have a very high quality response from 35-80Hz? That's obviously a crucial octave, and where most cone deflection takes place (averaged) with typical content.
So something like Dr. Edgar's Seizmik sub which is horn loaded, and doesn't go that low, has its place.
Though I don't know that I agree with calling anything without solid 25Hz response a sub. Just saying there's a lotta ways to skin a cat, and sometimes the really deep extension isn't necessary for great bass. FWIW, the edgar 'woofer' sounds superb.
Cloth Ears said:
...well there is a lot of signal in DVDs and CD below 20Hz. I am aware of that since I am running a system that is flat down to 12 Hz (..what you might call flat... frequency response is more looking like the skyline of the Himalaya.. ), and rolling off below that with 2nd order.
But I came to the conclusion that most of these subsonic signals are not information, but junk. Means there is a lot subsonic NOISE on loveless recorded CDs. I have added an adjustable 2nd order subsonic filter (Tschebbychef with 0.4db ripple, adjustable between 12Hz-63Hz) which I typically adjust to 17Hz.... Means system is flat down to 17Hz then rolls off with 2nd order and below 12Hz rolls off by 4th order.
...so far my trade off...
P.S:
Besides subsonic frequencies - one might have a look to very dramatic happenings in the audible bass frequencies... Room resonances!
Anybody ever measured rooms resonances? Do it!
...played around with notch filter EQ? Do it!
A very useful chart:
http://www.contrabass.com/pages/frequency.html
People always rush out with the "Pipe Organ = 16hz" flag, but it's worth pointing out that the lowest A on the piano is 27hz. A bass with a low C extension plays down to roughly 32hz and is not terribly uncommon in orchestral music. For me, a system should play well to 27hz as a minimum, with extension to the famous 16hz preferred.
Not that my current system does, but one must have goals...
http://www.contrabass.com/pages/frequency.html
People always rush out with the "Pipe Organ = 16hz" flag, but it's worth pointing out that the lowest A on the piano is 27hz. A bass with a low C extension plays down to roughly 32hz and is not terribly uncommon in orchestral music. For me, a system should play well to 27hz as a minimum, with extension to the famous 16hz preferred.
Not that my current system does, but one must have goals...
ChocoHolic said:
So your system is virtually flat to 12Hz, similar to mine. Then you should know of more material than just movies and pipe organ music that have usefull information well below 20Hz, even everyday pop/rock/top40/whatever music. It's there, you just need a system able to properly reproduce it.
As for this... "But I came to the conclusion that most of these subsonic signals are not information, but junk"... Simple solution to that is to avoid those lesser quality CDs.
jackinnj said:
Of course, nothing beats listening to the real deal. But darn it, I'll die trying to get my system as close as possible to the real thing.
It is quite amazing what the human mind is capable of when you have a loudspeaker system that can image and soundstage so well that it totally disappears (as well as the rooms walls) when you close your eyes and listen. Of course, excellent bass extension well below 20Hz needs to be there as well to make it that much more convincing.
geaugafletcher said:
Yes, you must have goals, but why set those goals so low. 27Hz is low, but not low enough and a lot of information will be lost.
If you have limited funds, limited "speaker building skills", or limited space in your room, but still want decent bass output down to at least 18Hz (maybe even 15Hz, depending on placement and room), buy an SVS PB10-NSD for a little over 400 bucks. It's quite a capable little sub that will give much larger, more expensive commercial subs a run for their money. I know, my brother has one.
Don't limit yourself to ONLY 27Hz.
chops said:
Easy to say, hard to do.
Since some years all large labels have discontinued the correct CD format and flood their discs with scrap, -called copy protection.
SONY, EMI, BMG... Some just sound poor, others do not work in many CD players at all or have interruptions. These interuptions make the lights in my room go down because the amp suddenly draws several kW in order to
throw DC-like signals of 100V to my innocent subs... And even if there are no interruptions in some CDs you simply see the cones flattering with some single Hz and high excursion, completely uncorelated to the music. I do not know if this is related to copy protection or not, but my newer CDs have more subsonic scrap than my old ones.
So what should I do? I am really wondering what these labels are doing. They are frustrating their last honest customers, while the copy guys are laughing, because it just needs one or two weeks until they can download the new appropriate ripping software for the newest CDs.
How/where do you buy high quality CDs? In the meantime I am already happy if my player does play a new CD at all ...
ChocoHolic said:
Off topic, but I agree completely. Joe Average buys one of these products and wonders why he's too dumb to get it working in his PC/DVD player/car sound system etc., when it's actually because he's been sold a poisoned product.
As you note, none of this stops the dedicated pirates, as they have the tools and skills to create rips, which they can then freely distribute.
The great irony of this is that I recall always being told by the industry that a pirated copy was inferior to an original. I would argue that a well ripped CD or DVD - with the relevant poisoning removed - is a better product, and, amusingly, is likely to be more compatible than the original.
The fact that I tend to do such rips on my own DVDs and CDs (though I try to avoid buying the poisioned CDs in the first place) probably means I'm breaking the law, despite the copies being for my own use only.
ChocoHolic said:
Easy to say, hard to do.
Since some years all large labels have discontinued the correct CD format and flood their discs with scrap, -called copy protection.
SONY, EMI, BMG... Some just sound poor, others do not work in many CD players at all or have interruptions. These interuptions make the lights in my room go down because the amp suddenly draws several kW in order to
throw DC-like signals of 100V to my innocent subs... And even if there are no interruptions in some CDs you simply see the cones flattering with some single Hz and high excursion, completely uncorelated to the music. I do not know if this is related to copy protection or not, but my newer CDs have more subsonic scrap than my old ones.
So what should I do? I am really wondering what these labels are doing. They are frustrating their last honest customers, while the copy guys are laughing, because it just needs one or two weeks until they can download the new appropriate ripping software for the newest CDs.
How/where do you buy high quality CDs? In the meantime I am already happy if my player does play a new CD at all ...
sploo said:
Off topic, but I agree completely. Joe Average buys one of these products and wonders why he's too dumb to get it working in his PC/DVD player/car sound system etc., when it's actually because he's been sold a poisoned product.
As you note, none of this stops the dedicated pirates, as they have the tools and skills to create rips, which they can then freely distribute.
The great irony of this is that I recall always being told by the industry that a pirated copy was inferior to an original. I would argue that a well ripped CD or DVD - with the relevant poisoning removed - is a better product, and, amusingly, is likely to be more compatible than the original.
The fact that I tend to do such rips on my own DVDs and CDs (though I try to avoid buying the poisioned CDs in the first place) probably means I'm breaking the law, despite the copies being for my own use only.
Hmm... Maybe it's something the recording labels are doing to CDs across the pond, but over here in the US, at least with the CDs that I've bought recently, I've never had a single one of those issues, nor have I had any of that "scrap" flopping my sub around and sucking all the power out of my amp.
At least, not yet...
I'm in the Uk and haven't found a cd that won't play on my system yet.... Haven't had any infrabass glitches either..
I've had a few dvd's that don't want to play thanks to sony though... In that case I have to rip them to work, which is frustrating as I own the original legal versions..
Rob.
Any examples of these infrabass power sucking cd's ? In case I have the same albums and can compare.
I've had a few dvd's that don't want to play thanks to sony though... In that case I have to rip them to work, which is frustrating as I own the original legal versions..
Rob.
Any examples of these infrabass power sucking cd's ? In case I have the same albums and can compare.
I've never had the infrabass problem that's been mentioned, but I've seen a few poisoned CDs around.
A friend asked me to sort out a "Kings of Leon" CD that looked like it had a corrupted TOC in a second session (most CD players will only see the first session, so will work. PCs, and may DVD players will read all sessions, and would get the corrupt TOC). I did see some 'boyband' album that had a similar system (we were testing it... not listening to it... honest!)
There's a Chili Peppers "best-of" that has one of the protection systems, but I don't know which one.
I've read news articles about a couple of systems (one was Sony backed IRC) that installed stuff on your PC, which could then be exploited by VX writers as the software hadn't been well written.
I've also found a few CDs recently that won't rip to MP3 with tools like Realplayer, but doing a lower level extraction with stuff like Nero works fine.
I'd also consider the region locking on DVDs (especially RCE) to be a form of poisoning. I understand there are marketing and logistical reasons why the industry wants you to buy a disk from your local area, but if you travel (legally) and buy a legal copy of a DVD, and put it in your (legally owned) DVD player, and it tells you to take a walk... well... I just don't think that's good!
A friend asked me to sort out a "Kings of Leon" CD that looked like it had a corrupted TOC in a second session (most CD players will only see the first session, so will work. PCs, and may DVD players will read all sessions, and would get the corrupt TOC). I did see some 'boyband' album that had a similar system (we were testing it... not listening to it... honest!)
There's a Chili Peppers "best-of" that has one of the protection systems, but I don't know which one.
I've read news articles about a couple of systems (one was Sony backed IRC) that installed stuff on your PC, which could then be exploited by VX writers as the software hadn't been well written.
I've also found a few CDs recently that won't rip to MP3 with tools like Realplayer, but doing a lower level extraction with stuff like Nero works fine.
I'd also consider the region locking on DVDs (especially RCE) to be a form of poisoning. I understand there are marketing and logistical reasons why the industry wants you to buy a disk from your local area, but if you travel (legally) and buy a legal copy of a DVD, and put it in your (legally owned) DVD player, and it tells you to take a walk... well... I just don't think that's good!
Moderators I would be happy if you shift the last few postings to a new thread. I think the infrabass noise is an interesting topic and discussion might go on...
CDs that make trouble with CD-player (NAD T 571):
Sony BMG, Bravo The HITS 2006: Interruptions
Warner Music, NENA, WILLST DU MIT MIR GEHN: Interruptions & Infra noise
Arista RCA BMG, Avril Lavigne, UNDER MY SKIN: 'Disc Error'
... and more. After going through it, I get the impression that SONY BMG and also EMI make most headache to me.
Trouble free:
Maverick Recording, Madonna, ray of light: A lot of infrasonic signals but clearly song corelated.
Universal Music, GUNS N' ROSES Greatest Hits: Not much infra content.
Atlantic Recording, Foreigner, 4: Fat bass in several tracks i.e. Juke Box Hero, but no issue.
In general I think it is not only a question of the disc, but also an interaction between disc and the player. Reading errors, error correction & filters all this together will probably strongly influence the resulting output signals.
CDs that make trouble with CD-player (NAD T 571):
Sony BMG, Bravo The HITS 2006: Interruptions
Warner Music, NENA, WILLST DU MIT MIR GEHN: Interruptions & Infra noise
Arista RCA BMG, Avril Lavigne, UNDER MY SKIN: 'Disc Error'
... and more. After going through it, I get the impression that SONY BMG and also EMI make most headache to me.
Trouble free:
Maverick Recording, Madonna, ray of light: A lot of infrasonic signals but clearly song corelated.
Universal Music, GUNS N' ROSES Greatest Hits: Not much infra content.
Atlantic Recording, Foreigner, 4: Fat bass in several tracks i.e. Juke Box Hero, but no issue.
In general I think it is not only a question of the disc, but also an interaction between disc and the player. Reading errors, error correction & filters all this together will probably strongly influence the resulting output signals.
ChocoHolic said:
Agreed - I did take it a bit off topic... sorry.
I am interesting in the infrabass issue you've mentioned. Would it be possible for you to post/host some short clips of sections that cause problems? I really can't see there being a legal issue for 2-3 second wav files being distributed.
EDIT: Thinking about your comment "Reading errors, error correction & filters all this together will probably strongly influence the resulting output signals.". What happens if you take a CD copy of the discs? I have found a few CDs whose physical surface is poor, but can be extracted with a good CD-ROM drive (albeit sometimes taking a long time and suffering lots of retries). The subsequently written CDR (on good quality media) is usually fine.
I purchased some TC Sounds 12" drivers for the project that caused me to create this thread.
My buddy is now saying "But you told me you could get me under 20hz. And why did you get little 12" drivers. Why not 15!?!".
He sounded kind of disappointed. Like I already messed up. Well, the TC-Sounds have an Fs=23hz. And while I like the I'm-trying-to-compensate-for-something 18" drivers idea. I do have to mate these with his other subs or at least his Klipsch speakers in a way that doesn't ruin his music all for the sake of movies.
Should I attempt
a) big, big vented box with tuning somewhat lowed than Fs?
b) small sealed box with Linwitz transform
c) big, big sealed box
My buddy is asking for under 20hz, but the problem is I don't think his current system produces much SPL under 30hz.
Hope I can get a decent result with these drivers.
They should be able to play loud down low. I'm not sure the sound quality is better than Dayton Reference subs. But then I haven't hooked them up yet.
I'm sort of in the camp that bass below 20hz doesn't do anything for music. Too many things in the room start to rattle at some of those low frequencies.
My buddy is now saying "But you told me you could get me under 20hz. And why did you get little 12" drivers. Why not 15!?!".
He sounded kind of disappointed. Like I already messed up. Well, the TC-Sounds have an Fs=23hz. And while I like the I'm-trying-to-compensate-for-something 18" drivers idea. I do have to mate these with his other subs or at least his Klipsch speakers in a way that doesn't ruin his music all for the sake of movies.
Should I attempt
a) big, big vented box with tuning somewhat lowed than Fs?
b) small sealed box with Linwitz transform
c) big, big sealed box
My buddy is asking for under 20hz, but the problem is I don't think his current system produces much SPL under 30hz.
Hope I can get a decent result with these drivers.
They should be able to play loud down low. I'm not sure the sound quality is better than Dayton Reference subs. But then I haven't hooked them up yet.
I'm sort of in the camp that bass below 20hz doesn't do anything for music. Too many things in the room start to rattle at some of those low frequencies.
Do you have the TC-1000, 2000 or 3000 series?
In any case they seem to be capable of quite some volume displacement.
Version 1: Big, big vented design.
Well it will be big, but as long as you can make sure that there is not to much signal below the tuning frequency this approach should work. Below the tuning frequency vented designs do flatter with the cone but do not generate much sound anymore.
Version 2: Small sealed with LT.
You need some electronic skills to get it running in a proper way. And your friend will need quite some powerful amp.
Version 3:
The simplest solution, but large and less sound pressure than version 1. Good point: Suitful and forgiving behavoir even for very low frequencies.
Version 4:
If you are a freak and want to get as much as possible from this driver, you could go for a sealed design with LT and horn loading. But the opening rate of a low frequency horn is very small, so would need a very long slowly opening huge horn....
My personal approach is version 2, if I need more power then I can start stacking multiple of such subs....
This is modular, flexible and gives the best ratio of output/size.
In any case they seem to be capable of quite some volume displacement.
Version 1: Big, big vented design.
Well it will be big, but as long as you can make sure that there is not to much signal below the tuning frequency this approach should work. Below the tuning frequency vented designs do flatter with the cone but do not generate much sound anymore.
Version 2: Small sealed with LT.
You need some electronic skills to get it running in a proper way. And your friend will need quite some powerful amp.
Version 3:
The simplest solution, but large and less sound pressure than version 1. Good point: Suitful and forgiving behavoir even for very low frequencies.
Version 4:
If you are a freak and want to get as much as possible from this driver, you could go for a sealed design with LT and horn loading. But the opening rate of a low frequency horn is very small, so would need a very long slowly opening huge horn....
My personal approach is version 2, if I need more power then I can start stacking multiple of such subs....
This is modular, flexible and gives the best ratio of output/size.