Axiom Home Page Forums General Discussion Home Theater LFE at low volume

Is it possible to get 20hz or lower at low volume?
How do you measure the level without a computer?
Does the size of the driver and or the enclosure help at lower volumes?

1) I would think so although you would have to elaborate what low volume means to you. To me low volume is below -25 db which my wife still thinks is loud'ish.

2) You need a SPL meter. Radio Shack carries an inexpensive one however I would recommend a unit like this one which is far more accurate. I have it and it's good.
http://www.long-mcquade.com/products/556...e_SPL_Meter.htm

Ultimately though, you (and your walls and picture frames) will feel 20hz in your body far more than hear it with your ears.

3) When you get to 20hz and lower you absolutely need a really good driver and enclosure. My EP500 works in this range (just barely though) where as my 10" Polk sub produces no output. You will need a 12" long throw/high output driver at minimum. Ultimately though this is EP600/800 territory. The large enclosure really helps.

Anyway, I am sure others will chime but these are my thoughts. However to be honest, my knowledge on these topics is quite dated and may not be totally accurate with today's speakers.

The above stated is right. Below 20Hz you won't hear anything because the sound waves are so large. You still need relatively a lot of power to push the subwoofer driver down that deep because it will be moving a good amount of air even if our ears can't hear it.

So I would think that being able to "feel" it under 20Hz at a low enough volume level that you aren't getting a good amount of "above 20Hz" LFE could prove to be a challenge. Also keep in mind that many times the LFE seems louder in a next door room than it does inside the room with the sub. This also happens in car audio where the bass may be moderate inside a car, but outside seem louder. I was told that it was due to how *long* the sound waves are and that they are (in laymen's terms) outside of the car at really low frequescies before being able to be heard.

Not sure if that is exactly true or not, but I can say this; My family will be watching a TV show in our living room where we have a fairly inexpensive Sony HTIB. They won't have it very loud at all, and I get still hear the subwoofer through the wall in the bedroom. The lower frequecies are just harder to trap inside a space. Ever go to a movie theater early enough that the previews haven't even started? Many times you can hear the LFE of the auditorium right next door despite their efforts in acoustical treatments and sound deadening in each theater.

To answer the other questions, use a SPL meter like mentioned above, and if sub-20Hz is wanted, then a large driver/enclosure will get you there easier than a smaller one. I've got a SVS sub that has almost a 4 CuFt ported enclosure with a 12" woofer and it touches 20Hz, but doesn't go below it. Some people have modded their's to do it, but really you would be more successful with a 15" woofer.

So, I guess after all of these ramblings I should ask the question: Why are your trying to get sub-audible LFE at low levels? I mean, that is the "feel it" zone and if you still want to "feel it" then you are going to need to leave the levels turned up a bit.

Or use tactile transducers (bass/butt shakers). You feel it then, even with the audible levels turned down. I had bass shakers in my first theater, and they are back for V4 and everyone loves them. Mine are set to be a little subtle and to augment the subwoofer itself, but they give the "feel" of sub-20Hz even if I turn the speakers and sub down since they are on their own power source and can be turned up/down independantly.

Although, my room is dedicated and fairly isolated - bedroom mentioned earlier where the TV in the room next door is heard even at low levels, and I can barely hear an action movie going in the theater right below - so I don't worry about turning it down much. Keeps the wife happy.

There's also the human hearing element: our ears are less sensitive to low frequencies (and high?) than to midrange frequencies. So for our hearing to perceive the low frequencies at low volumes, they have to be proportionally louder than the midrange frequencies. That was the idea behind the old "loudness" buttons and behind Audyssey's Dynamic EQ.

To answer the why...
Since purchasing my M80's we've done a 180. We now listen to way more music than movie watching. I still watch movies (when the stars align) but in general if I'm home (and awake) the stereos on.
I've found alot of good online radio stations but I find I can't get the right bass. I know theres more for alot of the songs.
I'm pretty sure there has to be a way to get true full range at breakfast volume(65db @ 4meters).

That's funny, I have M80s too and didn't listen to music much with my Denon 4311ci. Then I got the 3ch ADA1000 and nor listen to music a lot

However to you point, there is not much music content below 20hz. I suspect that what your missing is bass in the range of 60-120hz. That is the punch you feel with most modern music. I don't know that online radio stations provide high quality music content to extend well into the low and high ranges. Also, have you performed room equalization?

I have adjusted the SPL for each speaker but nothing more.
I couldn't get the subs SPL to match but they sound better than ever ( thanks to posts on this forum).
I have found quite a few online stations with good audio and good bass output.
I have really good bass and its not boomy at any volume. That said I'm pretty sure its my system holding up the lower frequencies.
My M80's almost cover the audible bass. They hold their own very well.
I'm sure I'm missing something.

2 EP 600's provide pretty good LFE at a lower volume... Much more "fill" if you will.. Plays loud enough that you get the effect, without shaking the house.. However, they can also do the latter if one so chooses....

EP600's are out of the question while were in our current home.
I'm curious to know if a 15" Axiom driver is in the works.
My subs are good, just looking for what would seem to be the missing piece of the sound puzzle.
I want to turn down the volume (and I will, ever so slightly) but turn up the lower frequencies heard.
Time to look into room treatments and or better subs.

First point, LFE is low frequency effects occasionally present in the .1 channel in movies. Music has no LFE. With the notable exception of pipe organ music there's almost no bass content below about 40Hz.

Bass frequencies require no more power for a given level than any other; e.g., 20Hz, 200Hz and 2000Hz at 80dB use the same power. What is different is that deep bass frequencies are less audible to humans than are higher frequencies at the same dB level. If you want to make them more audible(or at least equally audible)in relation to the rest of the music, the simplest move is to turn up the bass tone control. There are also built-in or separate parametric equalizers to try to do this a bit more precisely. This boosted audibility of the lowest bass isn't "natural", of course.

So no, your system isn't "holding up the lower frequencies" and you aren't "missing something" that you're supposed to hear.

No LFE. The missing piece of the puzzle.
I should have know that, I turn my subs off when using Pure Direct.
Anyway I figured it out. I turned my subs down on each subs back panel. Turns out they both sound better at a +/-33% setting. Theres more reverb/realism to the drums.

The lowest note on my 5-String Electric Bass is 'B0' - 30Hz or so.

The fat 'B' string is rarely played 'open' though so the vast majority of notes are higher than 30 Hz...

TAM

I think they were set +/- 5% too high and the sound/detail wasn't being heard over the volume/difference.
Cross over at 80, both subs volume at 33%, AVR @ 0.
I've tried different cross overs but not since changing the subs volume.
Clearly I don't know as much about the technical side of setting up my system as most here. I know more than most in my circle, that's enough.
I enjoy the tweaking and will live with it as is for a while.

Have you compared the M80s in pure direct to the M80s set to small with the subs?

2 things come to mind: your subs may not be optimally placed, your subs are not very capable in the 40-80 Hz region.

I know that with music, pipe organ excepted, I can't tell the difference between M80s alone vs M80s + ep350.

It could be everythings normal. I'd have no way of knowing.
The subs are in the front corners outside the M80's.
The Paradigm PS1200v4 is on the left half its width off the side wall half its depth of the rear wall.
Low Frequency Extension: 21Hz (DIN)
The Paradigm DSP3100 is on the right half its width off the side wall half its depth off the rear wall.
Low-Frequency Extension*24 Hz (DIN)
I do get some very nice lows from them but until I turned them down it wasn't quite right.
I'm tempted to turn the subs down to +/-25% on the back panels and adjust the AVR up a few db.

I'll take a shot and say you are used to the way these songs sound on your old speakers which might not have had a flat response and boosted the bass a little too much and as the others have stated you are not looking for extremely low bass, ie. 20 hz and lower unless you are listening to pipe organ music. Most music bass is 30 hz and up and for the most part as was previously stated , 60 hz and up to provide that punchy bass, is what most are looking for from music and your M80s are more than capable of producing these frequencies. 65 SPL is pretty low volume for a speaker to play bass frequencies with authority(noticeable) unless they have a boosted FR in this region or some other anomaly that gives perceived better bass.

You could always add some bass boost via the receiver to enhance the response for low level SPL listening.

I haven't seen it mentioned yet but, have you checked your phase position on the subs because improper setting in this category can also affect what your hearing especially when you have more than one sub from different manufacturers interacting with your Axiom mains. In music the vast majority of bass is not much below 60HZ and that is only when played at the lowest register which in most cases is not always done by the player on the recording. I also find bass response can vary widely in different recordings. There is rarely anything below 20HZ anyway even in movies and if it is present, you will feel it not hear it. The very deep bass in movies can generally only be heard at relatively high volumes, otherwise, if it was mixed at louder levels with moderate volume, when cranked up to movie levels, it would more than likely overdrive your speakers, even your subs.

The human ear(and even SPL meters)do not hear or measure bass accurately below 50HZ and like the highs, it gets worse the older you get so the controls should be adjusted accordingly. This is probably one of the main reasons why not everyone likes the results from "room correction" systems. Sometimes what the AVR measures as being accurate in your room does not always translate to what your ears are hearing(or like).

The older AVRs had a bass boost button which was specifically designed to be used primarily at lower volumes to compensate for that hearing loss in that range. At higher volumes, it was way too much. The 80HZ crossover which has always been the THX standard for movies just seems to be the most flexible for all types of listening, so set it to that number, make sure your sub phases are correct and adjust the sub volume to taste and you should be fine with the ultimate goal of hearing the music/movies the way they are suppose to sound.

Its all good.

" To me low volume is below -25 db which my wife still thinks is loud'ish."

@ -25 in 2 channel and 2 subs it does feel like theres an LFE signal. I can feel it in my chest and the spl meter on my phones only registering 78-80 as is right l this.
I love this hobby.

The hobby is fun, it does get costly. My challenge is sneaking in new stuff without the wife noticing... I am now thinking of replacing my VP150 with a VP180, I will need much smoke and mirrors to get this past her...

Also I am sure you already know this but 2ch music does not include a LFE channel, it's actually your receiver routing low frequencies to LFE and your subs.

"I will need much smoke and mirrors to get this past her..."

You'll need a custom speaker grill with an iron on VP150.
Best of luck.
The 180 would live up to the "Monster" description its been given.
Its over twice the length, over twice the height and 3 times as deep as my current center.
I want one.
Catch is none of my stuff will work with it. The stand my TV is on can't hold any more weight and even if it could my TV can't be wall mounted (there's no wall behind it).
Why is it we want the things we can't have until we have them and then a week or so later we move onto the next thing we can't have.
I feel guilty.I just had this talk with my kids.

I have this problem too. I think it's called greed.

If the present cabinet/stand is removed, can the TV sit on an M80?

Greed is not the right word. I'm not sure what is.
I'm thinking its a good time to spoil myself. Bills are paid, got a few bucks stashed away,..aside from the potential looming bankruptcy at work alls good.
The TV could sit above the M80 but obviously not on it. It was just a thought.
The V3 VP180 seems to be the one. There is no better match for the M80 yet. Its a shame this one upgrade is going to cost quite a bit.
I'm looking at a new enclosed lowboy unit, self supporting stand and the center.

UPGRADEITIS

Nope. I've had that before.
This is more like needing to replace an old dog except this center is only a year and a half old.

At only a year and half I would say it is still upgradeitis but a modified strain.

It's easier with the wifes approval.

Most definitely

Greed: a selfish desire to posess more of something than what's needed.

It fits.

Except that I'm neither greedy or selfish. Needy maybe.
Its obvious my systems pretty good until I use the center channel. I hate to use the word "want" but...
I was thinking QS8's or the new full range center would be a good birthday gift for myself.
Since my QS4's are doing a fine job set up at 85° the center is at the top of the list.

Not implying anybody is greedy or selfish (except myself). A good center will improve your listening enjoyment. I've used them all from VP160 down. For horizontal centers, I wouldn't want to go anything less than a VP160. My 2nd choice would be VP150. My vertical M22 mounted over the top of the TV, along with matching M22's left and right, makes an excellent sound field. There really isn't anything better than 3 matching speakers. The VP160 under the TV adds some fullness that wouldn't be there otherwise.

Lately been playing with Pioneers sound options because I downloaded the app for it on my iPad, which makes it simple to change. I like switching between THX Cinema and the Font Wide sound options. Wide makes the sound feel like it's coming from the whole width of the front wall with my speakers mounted near the middle. I don't know how this works. But I don't think I like it better than TXH Cinema, or Pure Direct. I'm not hearing much, if any, difference between THX Cinema and Pure Direct.

"Have you compared the M80s in pure direct to the M80s set to small with the subs"

Since adjusting the subs I hadn't.
I went back and forth listening for the difference today.
The M80s have a nice amount of bass on their own. With the subs now set at the roughly the same volume they seem to disapear with the M80's.
I couldn't locate them before but it didn't sound right.
I'll leave them at 33% for a while.

brwsaw, i feel you.. and know where your coming from... This is part of the reason i got 2 600's, with a 3rd "in the works". You could do like john said and turn up the subs volume.. Also, you could adjust your cross over points, my 600's are set to 80hz i think.....


The only real way you can get what your looking for is by having large drivers, like you mentioned. as well as multiple drivers...


Maybe a single EP800, if you can't get dual 600's?


What is your current sub? post a link so we can see where you're coming from.


If Ian made an 18" driver sub, i would buy one... Just saying... Incase Ian or andrew come across this thread......

http://overture-audio.com/product_lines/paradigm/html/ps1200.html

http://www.paradigm.com/products/products-by-category/subwoofer/paradigm/dsp-series/dsp-3100

I'm good now.
Its funny, I prefer the M80's bass in pure direct when I'm in the next room but for movies, tv, radio subs are on.