Auralex GRAMMA ? Anyone got one?

[dobyblue]

Originally Posted by DavePS3

Boy, would I love to meet you in the flesh! You don't know it all.

Perhaps we can see if we can arrange a demonstration at the anechoic chamber at Paradigm's Mississauga location to show you how foolish you are.

You continue to ignore what people who are educated in this matter are telling you, with absolutely ridiculous anecdotal evidence.

It would be like me telling you the sun is actually only 30,000 miles away and refusing to believe all the scientific evidence that shows it's 93 million miles away. That is how mundane this conversation has become.

You have a huge opportunity to learn here, but you think you are right and that's all that matters to you. That is what a mule is like.

[Riff Magnum]

Originally Posted by DavePS3

Boy, would I love to meet you in the flesh! You don't know it all.

You really need to give up the fight there fella. It's now embarrassing to be you. Terrence makes a living working with sound. Do you? These audio principles are not really debatable. These are not theories or hypothesis; they're laws.

[Sir Terrence]

Originally Posted by mattym

i would recommend the Gramma also, if you dont fancy one of those and want to make something a little different you can buy the foam from auralex for the base, and then add a nice marble top..

Sir Terrance..I hold a Post Grad Diploma in acoustics in the UK, I agree with you completely on all points except 1, Cedia trained installers..a few of them who have done the acoustic courses still insist on coating rooms in 25mm fiberglass with no real bass control or consideration for other frequencues, is this the way that they are trained or are they just saving money but not engaging an Acoustician?? In the UK we hae even given this service for free to some installers. Some of the designers are doing their customers a disservice!

They are trying to save money plain and simple. You are right though, I have had to go to many an over damped room to correct what some idiot who was not qualified to handle acoustical issues has done. Quite a few where CEDIA trained, but not certified in acoustics though.

[Sir Terrence]

Originally Posted by mattym

zippo dont bother with foam bass traps, get some rigid fiber panels and place them across the corners, the thicker the better, the foam traps from ANY company are just foam parts to match the foam panels they sell, they dont do anything meaningful with bass frequencies below 125hz

Good advice!

[DavePS3]

Originally Posted by dobyblue

You don't understand frequencies...and speaker phase is 100% irrelevant to this discussion, let's not use misdirection here.

Not one person has stated you cannot hear bass below 80Hz!!

Your opinion is 100% incorrect and you are either lying here, have extremely crappy crossovers or just don't have a clue how to set up equipment.

Period.

It's all about what a person can hear or detect. He stated a person cannot hear frequencies below 80hz. I disagreed. He stated that a subwoofer sounds the same no matter where it is in a room and the shape, acoustics of a room make no difference nor does how the sub is facing. I totally disagree. My point about speakers out of phase is that some people can hear it, some can't. Some people have a hard time with low bass - it hurts their ears. Most sub manufacturers suggest best positioning for their sub's. Right in the owners manuals, plus suggest reasons for optional phase selection and crossover. Why do you think they do that?

If you take aa hardwood floor, in a hard room and place the sub in the middle, the characteristics are totally different if you cover the floor in broadloom and hide it in a corner. If you as well as he, believe that bass is totally non-directional... you are dead wrong. It is MORE non-directional than mids or highs but unless you're down to 20 or 18hz... most people I know agree that it is not totally non-directional despite what a course tells you.

[DavePS3]

Originally Posted by Riff Magnum

You really need to give up the fight there fella. It's now embarrassing to be you. Terrence makes a living working with sound. Do you? These audio principles are not really debatable. These are not theories or hypothesis; they're laws.

Yes I do... I have since 1980.

[DavePS3]

Originally Posted by mattym

Daveps3 have you ever been in an anachoic chamber? or a 200cu/m reverberation chamber and done any testing on low frequency units? Do you understand how Modal frequencies interact with a room? Do you understand diffraction? how many rooms do you go into and analyse every week? What test gear do you use? you THINK you know that the sound is coming from point X with a sub, but if you went into a room blindfold, with the audio gear correctly set up, you WOULD NOT be able to tell where the bass was coming from. You really wouldnt.

I'm not talking about chambers... I'm talking about customers rooms. I'm not saying I can tell everytime where the sub is, but I've been able to do it 75% of the time. When I can definately hear frequencies below 80hz... whan I can usually pick out where a sub is in a persons room, that suggests to me that the facts - scientifically speaking, are not always correct in every situation. No one I know, has an anechoic chamber in their house. Therefore, what works in a chamber... where conditions are perfect... where they write the laws of physics... does not always translate to to real world environment. To me, it's like a car that states MPG. In perfect conditions, yes but they always include 'your mileage may vary'. Same idea in audio I believe.

[DavePS3]

Anyway... we could go on forever about this so I'll step aside and say you guys are correct in many points. We're all like Bulls going at each other and it just aint worth it so... sorry to all you guys, more power to ya, and best of luck in your related fields.

[ZIPPO]

$279 for 8 LENRDs from sweetwater.com

[JJ]

Great read, this thread - haven't seen something this messy since that time in '73 back in Burma when I saw a pack of 5 leopards hunt a small deer.

[dobyblue]

Again you have completely misunderstood or misconstrued everything that has been said here.

Originally Posted by DavePS3

It's all about what a person can hear or detect. He stated a person cannot hear frequencies below 80hz.

No he did not. This is what he said:

Originally Posted by Sir Terrence

No, your ears cannot pin point bass below 80hz, and that has been proven over and over again. You may be able to FEEL the pressure wave, but you will not be able to pin point which direction that bass is coming from with your ears. Our ears get less and less sensitive to direction and amplitude as the frequency drops. So your claims that you can detect direction flies in the very face of proven science, which makes your claims not so believeable.

You are confusing directionality with hearing Dave.

Originally Posted by DavePS3

]He stated that a subwoofer sounds the same no matter where it is in a room and the shape, acoustics of a room make no difference

Wrong again - that wasn't said at all. Placement makes a different, driver orientation does not.

Most sub manufacturers suggest best positioning for their sub's. Right in the owners manuals, plus suggest reasons for optional phase selection and crossover. Why do you think they do that?

Because subs carry information from under 20Hz to over 150Hz, that's why.
They don't want you to put your sub behind a wall anymore than your speaker. If you just want to cross it over at 30Hz, different story. They're writing manuals for joe schmoe who doesn't have a clue, not av-philes.

If you take aa hardwood floor, in a hard room and place the sub in the middle, the characteristics are totally different if you cover the floor in broadloom and hide it in a corner.

Which is just what was said:

Originally Posted by Sir Terrance

Subwoofer position within the room may be king, but not the position of the driver

In your case the position of the subwoofer is changing, but you make no mention of the driver position. Hence whether it's a side-firing, down-firing or forward firing is not important, only the location is, which no-one is arguing.

If you as well as he, believe that bass is totally non-directional... you are dead wrong. It is MORE non-directional than mids or highs but unless you're down to 20 or 18hz... most people I know agree that it is not totally non-directional despite what a course tells you.

Way to clearly undefine bass. 200Hz is bass and yes it's directional.
60Hz is bass and no it is not directional.

Originally Posted by DavePS3

I'm not talking about chambers... I'm talking about customers rooms. I'm not saying I can tell everytime where the sub is, but I've been able to do it 75% of the time. When I can definately hear frequencies below 80hz... whan I can usually pick out where a sub is in a persons room, that suggests to me that the facts - scientifically speaking, are not always correct in every situation. No one I know, has an anechoic chamber in their house. Therefore, what works in a chamber... where conditions are perfect... where they write the laws of physics... does not always translate to to real world environment. To me, it's like a car that states MPG. In perfect conditions, yes but they always include 'your mileage may vary'. Same idea in audio I believe.

Again, no-one is saying you can't hear frequencies below 80Hz, geez.
As for the anechoic chamber, what it does is shows you that the reasons why you "hear" these low frequencies you think you do with directionality has nothing to do with the actual sound, but everything else...because when you're in an anechoic chamber with no reflection points the subsonic bass cannot be placed.

[Sir Terrence]

Originally Posted by dobyblue

Again you have completely misunderstood or misconstrued everything that has been said here.


No he did not. This is what he said:



You are confusing directionality with hearing Dave.



Wrong again - that wasn't said at all. Placement makes a different, driver orientation does not.



Because subs carry information from under 20Hz to over 150Hz, that's why.
They don't want you to put your sub behind a wall anymore than your speaker. If you just want to cross it over at 30Hz, different story. They're writing manuals for joe schmoe who doesn't have a clue, not av-philes.



Which is just what was said:



In your case the position of the subwoofer is changing, but you make no mention of the driver position. Hence whether it's a side-firing, down-firing or forward firing is not important, only the location is, which no-one is arguing.



Way to clearly undefine bass. 200Hz is bass and yes it's directional.
60Hz is bass and no it is not directional.




Again, no-one is saying you can't hear frequencies below 80Hz, geez.
As for the anechoic chamber, what it does is shows you that the reasons why you "hear" these low frequencies you think you do with directionality has nothing to do with the actual sound, but everything else...because when you're in an anechoic chamber with no reflection points the subsonic bass cannot be placed.

Thanks Doby. Based on what he has posted, I am sure the folks who give him his information got it right, but he is interpreting it completely wrong just like he has done here.

[Intamin]

Originally Posted by DavePS3

It's all about what a person can hear or detect. He stated a person cannot hear frequencies below 80hz. I disagreed. He stated that a subwoofer sounds the same no matter where it is in a room and the shape, acoustics of a room make no difference nor does how the sub is facing. I totally disagree. My point about speakers out of phase is that some people can hear it, some can't. Some people have a hard time with low bass - it hurts their ears. Most sub manufacturers suggest best positioning for their sub's. Right in the owners manuals, plus suggest reasons for optional phase selection and crossover. Why do you think they do that?

He didn't state you can't hear frequencies below 80hz, he said frequency from 80hz down are non-directional. And since you brought up owner's manuals suggesting placement, the owner's manual from a def-tech sub also states "Your Definitive Technology subwoofer has been designed to operate at frequencies generally below 150 Hz. Because low-frequency information in this range essentially is non-directional, your subwoofer can be located anywhere in your listening room that is most convenient." They say "essentially" because as Sir Terrance stated, it's 80hz and down that is non-directional, and since this sub is meant to operate at 150hz and down, part of the frequency range will be directional.

[Big Daddy]

Distortion, suspension noise, port noise, and cabinet resonances occur at HIGHER frequencies than 80 Hz, increasing the mind's ability to locate where a subwoofer is located. That is one reason why we have downfiring subwoofers, so that a sub can fire down onto a carpet/throw rug and any rare noises from the driver can be absorbed by the carpet, and the non-directional characteristics of low frequency bass can be strengthened.

[tilallr1]

Sorry to bring up this old thread.

Curious if anyone has tried these on carpet/pad covered concrete floors. I am not so worried about improving the sub's sound as I am about my walls/room shaking. Especially at lower frequencies. Which I get a lot of in my current setup. Could the GRAMMA reduce this or eliminate it?

I thought a concrete floor in combination with a think pad and carpet would be dense enough as hell to prevent any vibration issues. But I am learning as I read that concrete in some cases can be worse than hard wood floors.

So I guess I want peoples opinion of whether or not it made a difference for them in a similar setup as mine.

Let me know, thanks guys.

[Erman_94]

Hey guys, I really want to buy this but I'm worried it won't be big enough for my sub.

Can anyone confirm using this riser with the ed A2-300?

It seems borderline that it may or may not fit...

[Tufelhundin]

I have Great grammas for my PBU's Size: 27” D x 20.5 " W x 22" H (w/o grill) , with the grill you can add couple more inches and they still fit perfectly on the pads.

As for the question above concerning th grammas on on carpet....I had mine on it for a short period, it did quell some fo the vibrations through out the house, but REW confirmed what I was feeling....the bass frequency was weaker....not sure if I have the graphs saved or not but there was a difference no doubt in my system. here in Italy I have both of my PBUS on grammas on tile floors....havent hooked them up yet....