Bass trap placement - high or low? Does it matter? - Page 11 - Home Theater Forum and Systems - HomeTheaterShack.com

Reply
 
Thread Tools
post #101 of 110 Old 03-07-14, 04:27 PM
Senior Shackster
John
 
Join Date: Feb 2012
Location: Michigan
Posts: 324
My System
Send a message via Skype™ to phazewolf
What I am saying is with no sub all of it is sent to your mains and that may not be the best idea even a small sub can be helpful.

Not everyone want the low frequency information but they should also be shown what they are missing by giving up it too. I am still unsure if the lfe channel is redirected to the mains or not when there is no sub. Some say yes some no I would need to use a scope and take a look at what is going on I guess.
phazewolf is offline  
Sponsored Links
Advertisement
 
post #102 of 110 Old 03-07-14, 04:40 PM
Plain ole user
 
lcaillo's Avatar
Tech Guru
 
Join Date: May 2006
Location: Gainesville, FL, USA
Posts: 11,121
Send a message via AIM to lcaillo
Re: Bass trap placement - high or low? Does it matter?

I don't disagree. I am just saying that for many, if not most people it probably is meaningless. I have done thousands of demos and installed and calibrated hundreds of systems. Most people just don't care. Even among those that care a lot about sound quality, for many purposes they don't need a sub. With my Arx A5 I am just on the edge with music of needing more extension. I don't use them for HT at this time. In my HT I certainly do want a sub, but I don't need much below 30 Hz, certainly not below 20 Hz, to be satisfied.




Looking for me, just google my username. I have used the same one for most sites for many years.
lcaillo is offline  
post #103 of 110 Old 03-07-14, 05:22 PM
Senior Shackster
John
 
Join Date: Feb 2012
Location: Michigan
Posts: 324
My System
Send a message via Skype™ to phazewolf
When I setup my system I did not think it would hit to where it did. With the old setup before changing my mains I was flat to 17hz

Now I have no idea as I have not measured but the subs in there new location and with better mains it may drop lower I am not sure. It by sound and feel is dipping lower then before but who knows until I can check.

I am thinking about running the subs on the Legacy on the sub input off the avr and using that for one setup for one pair of subs and the twin 18 set on the other sub channel not sure how well that would work.
phazewolf is offline  
 
post #104 of 110 Old 03-07-14, 06:43 PM
Shackster
Babak
 
Join Date: Mar 2009
Location: Vienna
Posts: 59
Re: Bass trap placement - high or low? Does it matter?

Hi

Quote:
phazewolf wrote: View Post
Name a full range speaker that can do want sub can do in a room when placed where it will image and have good overall balance to the sound that can play down to 20hz or less when also placed on the nulls of a given room and cost under 10k

The best place for the speakers to image may not be on a room null and how often is the best most even location for bass in that spot?

And when I am talking full range I mean tested to be flat to 20hz or less without room gain being added in and not can play down to stuff that some company say but by time it is at 20hz it is down 25db
20 Hz or less, flat?
Where does the specification come from?

The frequency range of musical instruments very rarely reaches down to 20 Hz or even below.

You will know the frequency charts like this one from gearslutz.com:

They have left out the lowest tone of the pipe organ, the subcontra c at about 16 Hz (in German it's called the humbleness pipe).
Only some pieces use that pipe, for example Richard Strauss' "Also Sprach Zarathustra".

Also room responses of concert halls don't include frequencies that low.
The famous Golden Hall of the Vienna Musikverein (if you are watching the New Year's concert of the Vienna Philharmonic Orchestra, you will know it) has a well known mode at 21 Hz. But you don't hear that as strong as a room mode in a home theater.

------------

If you read the papers by Floyd Toole and Sean Olive on loudspeaker evaluation, you might know that they also determined how listeners rated the bass response of loudspeakers.

The found out that there was no real correlation between listener preference and the "flat" bass extension (the usual -3 dB limit).

But they found a correlation of listener preference with the -10 dB point. The lower that was, the better were the ratings.

That means tha speakers don't really need a deep flat bass responde (@ -3dB), but a flat roll-off in order to reach a deep -10 dB point.

------------
There are several speakers with those specifications, also at lower prices than 10k U$.

I'm using Shahinian Obelisk peakers, they reach 28 Hz @ -3dB and have bass roll-off of -6dB/octave.

------------

Regarding the placement.

If one is really serious about good sound reproduction, he won't make any coompromises.
So he would first place the speakers (e.g. onto the nulls) and build up his equilateral stereo-triangle from that.

But I'm aware that in most cases one needs to make compromises in regards of the placement.

------------

I think it is also important to note, that only looking at what frequencies can be resproduced at which levels is not really the correct way to estimate how well the result will be for the listener.

The human ear does not work that way.
It analyses the complete sound patterns, i.e. the enevlope curves consisting of a mixture of many frequencies.
One of the important elements of that envelope are onsets. Those consist of different frequencies rising at the same time.

If one places a subwoofer far away of a speaker, the low frequency onsets arrive at different times than the higher frequency onsets.
That diminishes the onset of the envelope cuve.

Even worse, if one uses one sub that is closer to one speaker and further away from the other.
This results in different envelopes from the left and right signal, making the bass "slow".
So, if using one sub, one should place it symmetrically between the two speakers.


Cheers
Babak
Babak is offline  
post #105 of 110 Old 03-07-14, 06:47 PM
Shackster
Babak
 
Join Date: Mar 2009
Location: Vienna
Posts: 59
Re: Bass trap placement - high or low? Does it matter?

By the way,

there is a system above U$ 10,000 that goes flat to 7 Hz @ 130 dB.

Listening to that is a really crazy experience ...
Babak is offline  
post #106 of 110 Old 03-07-14, 07:16 PM
Senior Shackster
John
 
Join Date: Feb 2012
Location: Michigan
Posts: 324
My System
Send a message via Skype™ to phazewolf
Yes I am aware that our ears can't hear all frequencies evenly and that to have the perspeced of flat the lower the bass freq the louder it needs to be to make one think that it's flat. Which is why a lot of people use a house curve to try and equalize such.

That is also why I like speakers that can play very low because if one ends up boosting the bass at the low octave to build a house curve if that is ones goal not everyone cares then you need to boost it less.

I like pipe organ music to a good low end is something that I want and look for in a speaker.

Also sense the audio spectrum we can hear is 20hz to 20khz that is what tend call full range. I would not call a car with a governor and a go-cart motor that can only 45mph a sports car and a speaker that rolls off at 40hz I would not call full range. Low frequency responds of a speaker a lot of times not all the time though tend to roll of very fast once you hit the point where they measure the -3db response.
phazewolf is offline  
post #107 of 110 Old 03-08-14, 07:02 AM
HTS Moderator
 
ajinfla's Avatar
AJ
 
Join Date: May 2009
Location: Tampa FL
Posts: 1,661
My System
Re: Bass trap placement - high or low? Does it matter?

Quote:
phazewolf wrote: View Post
Let me put it this way. The room is a audio nightmare, it sounded like a ecco chamber. You could clap your hand and hear the sound bounce around the room.

The floor is a slab of concrete and there is no carpet on it so it reflects everything more of less. The one wall is concrete with fake wood panel on it for show the kitchen wall is plaster and the other walls are wood studs which sit in front of brick outer wall and on the studs there is loosely tacked on 1/8 inch 1970's fake wood panel.
That seems atypical of most living rooms I've been in. Bare concrete floor?

Quote:
phazewolf wrote: View Post
The couch is leather so that does not soak up much and there is a nice door wall that messes up things as well.
Well, actually it does, though it will be slightly more reflective of HF. What about the loveseat, chairs, ottomans, rugs, drapes, media storage, wall art, etc, etc, etc??
Or is this a leather couch in bare concrete floor room?

Quote:
phazewolf wrote: View Post
As for the panels I have they were grabbed used off of Craig's list for $150 and I got 5 GIK 244 and 1 GIK 242 for that amount so not bad.
Not bad, but a $150 PE 3rd sub may have yielded as smooth (or smoother), over a wider area (if important), bass. With more output/headroom and lower distortion.
Of course it wouldn't function as an absorber.

Different strokes for different folks.
I did check out the GIK site and they are very reasonably priced. Must have been on sale when you bought though.

cheers

AJ

To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.
ajinfla is offline  
post #108 of 110 Old 03-08-14, 07:05 AM
HTS Moderator
 
ajinfla's Avatar
AJ
 
Join Date: May 2009
Location: Tampa FL
Posts: 1,661
My System
Re: Bass trap placement - high or low? Does it matter?

Quote:
Babak wrote: View Post
There are also other reasons why I would always prefer full range speakers on the right positions
Yes, I prefer 5 (with 40hz min capability) if you can.

cheers

AJ

To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.
ajinfla is offline  
post #109 of 110 Old 03-08-14, 11:23 AM
Shackster
Babak
 
Join Date: Mar 2009
Location: Vienna
Posts: 59
Re: Bass trap placement - high or low? Does it matter?

Hi

Quote:
phazewolf wrote: View Post
Yes I am aware that our ears can't hear all frequencies evenly and that to have the perspeced of flat the lower the bass freq the louder it needs to be to make one think that it's flat. Which is why a lot of people use a house curve to try and equalize such.
Obvisously you got me wrong.

I was not talking about the Fletcher-Munson curves or (more correctly) Robinson-Dadson curves which are the reason for people using EQs especially when playing at ow levels.

I was talking about a mecahnism of the human ear that is called "phase locking".

With subs in different locations than the speakers and with asymmetrical setup of one single sub you mess up the phase locking mechanism leading to a loss on precision.


Quote:
phazewolf wrote: View Post
I like pipe organ music to a good low end is something that I want and look for in a speaker.
Not many organs do have a subcontra c pipe with 16 Hz.
And not many pieces of music use that pipe.

And also those frequencies are not present with high intensities.

I'd really like to know how many recordings you have in your collection that use that pipe.

Quote:
phazewolf wrote: View Post
Also sense the audio spectrum we can hear is 20hz to 20khz that is what tend call full range. I would not call a car with a governor and a go-cart motor that can only 45mph a sports car and a speaker that rolls off at 40hz I would not call full range.
based on Floyd Toole's findings it's better to have a -6 dB per octave roll-of at 40 Hz than a -18 dB per octave roll-off at 20 Hz.


Again, the question is if one really needs it.

With driving speeds, the full range would go up to 200 mph or more. There are cars that can go that fast, and on many German Autobahns there are no speed limits, one could go with 300 mph as well if the car can go that fast.

So should people drive sports although they will not drive faster than 150 mph or more in 99,9% of their trips (even when living in Germany there are not too many opportunities to drive that fast due to the traffic)?

The same with music an low frequencies.
How many recordings does somebody listen to, that have frequencies of 20 Hz or less at high levels and where it would ruin the perceiption of the work if those frequencies are delivered at 3 or 6 dB less than it should be?

You can make some spectrum analysis from tracks to see how much there is at 20 Hz or belowm
You can also put a steep high pass filter at 20 Hz and listen to the track again to see, what the difference is.

Both can be shared in the forum.


Quote:
phazewolf wrote: View Post
Low frequency responds of a speaker a lot of times not all the time though tend to roll of very fast once you hit the point where they measure the -3db response.
That's one should look at the frequency response measurements of the speakers to see where the -10 dB point is.

And still there is the question:
How often is it neccessary to play frequencies below 30 Hz at high levels?

I think that's not very often.

Cheers
Babak
Babak is offline  
post #110 of 110 Old 03-08-14, 03:30 PM
Senior Shackster
John
 
Join Date: Feb 2012
Location: Michigan
Posts: 324
My System
Send a message via Skype™ to phazewolf
J am currently at work so I can't really get into everything but I use the system for both music and home theater which is why I like the ability to dig very deep.

As for a sub that would sound good and match well what I have for $150 that spent on trap I am not sure I could find one.

The traps I got were used but in good shape.

As.for phasing the subs the auto cal my Onkyo has sets the delay for each speaker and both subs independently and I can tweak it with the calibrated mic I have using REW.
phazewolf is offline  
Reply

Bookmarks

Tags
bass , high , low? , matter? , placement , trap

Quick Reply
Message:
Options

Register Now




PLEASE COMPLETE ALL REQUIRED FIELDS BELOW... THANKS!

REQUIRED FIELDS ON THIS PAGE
YOU MUST COMPLETE ALL OF THESE

Username
Password
Confirm Password
Email Address
Confirm Email Address
Random Question
Random Question #2




User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
PLEASE READ BELOW PRIOR TO ENTERING AN EMAIL ADDRESS!

ATTENTION!

YOU MUST ACTIVATE YOUR ACCOUNT!

Activation requires you reply to an email we will send you after you register... if you do not reply to this email, you will not be able to view certain areas of the forum or certain images... nor will you be able download software.

AN INVALID EMAIL ADDRESS WILL CAUSE YOUR ACCOUNT TO BE DELETED!

See our banned email list here: Banned Email List

We DO NOT respond to spamcop, boxtrapper and spamblocker emails... please add @hometheatershack DOT com to your whitelist prior to registering or you will get nowhere on your registration.


Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML is not allowed!
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 


For the best viewing experience please update your browser to Google Chrome