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# Seaton Sound SubMersive1 - Page 259

Yes, I understand what an octave is. That's why I specify in my above, the range of frequency (<120Hz) and two specific graphed examples (43Hz and 72Hz) as I ask; when a specific frequency is referenced, is that considered the beginning, middle or end of an octave?

I did some quick math for the above examples. If each of the referenced frequencies were in the middle of their respective octave, they would represent roughly 10% and 15% of each of their octaves. So I'd have a 3.4dB drop at 10% of the width of the first octave and a 7.3dB drop at 15% of the width of the second mentioned octave.

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Edited by BeeMan458 - 1/28/13 at 5:29pm

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Quote:
Originally Posted by BeeMan458

I understand what an octave is. That's why I specify in my above, the range of frequency (<120Hz) and two specific graphed examples (43Hz and 72Hz) as I ask; when a specific frequency is referenced, is that considered the beginning, middle or end of an octave?

without spending my night trying to scale everything out, if a dip were an octabe wide, it could be centered at 73 Hz, which is what your are looking at, which would have it running roughly from 50 to 100 Hz. the narrow dips you identify would be described as a fraction of an octave, like a sixth of an octave or something based on where the dip begins and ends . . .
Quote:
Originally Posted by JHAz

without spending my night trying to scale everything out, if a dip were an octabe wide, it could be centered at 73 Hz, which is what your are looking at, which would have it running roughly from 50 to 100 Hz. the narrow dips you identify would be described as a fraction of an octave, like a sixth of an octave or something based on where the dip begins and ends . . .

Thanks.

I did some quick math and the first example is 10% the width of the centered 43Hz octave and the second example is 15% of the width of the centered 73Hz octave. Is either sufficient to degrade the overall sound quality or are they so small that they don't degrade the sound quality; much in the same fashion that in the <120Hz range, THD distortion can hit 10% before it becomes noticeable? That sort of thing?

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Edited by BeeMan458 - 1/28/13 at 5:41pm
Quote:
Originally Posted by BeeMan458

When one learns how to think three dimensionally or spatially, they can see what's going on in a room as plain as one's hand in front of their face. Example, as long as one knows the rules and what the variables are, complex math equations are easy. That sort of thing.

The first trick is to know it can be done. Until then it seems impossible.

I have few talents but one of my talents is the ability to see and think three dimensionally and it gets old people telling me I can't do what I can do, all day long.-
Quote:
Originally Posted by BeeMan458

How well can we hear a dip that's 5Hz wide and 3dB deep?.

How well can we hear a dip that's 8Hz wide and 7dB deep?

Based on your above, the reason I ask is to find out how sensitive our hearing is to these types of expected fluctuations one might find in a standard REW frequency graph.

I'm trying to make sense of the two above quotes from you. Given your self-proclaimed ability to 3-dimensionally visualize a room's transfer function, it's surprising that you would need to ask about the audibility of different magnitude peaks or dips. Can't you just "visualize" them 3 dimensionally in your head and thereby *know* their impact?

Craig
I'm surprised that all of this is in the Submersive thread. Didn't someone ask for this topic to be moved to it's own thread in one of the many other subwoofer threads it's derailed the last few days?
Derailing is an objective of some posters.
Quote:
Originally Posted by RMK!

I would hope the the +or-3db filters would lead to measurable differences but it is the audible part that I find unreliable.
Quote:
Originally Posted by Mark Seaton

+/-3dB or more can be hard to hear when they are narrow peaks or dips. When you start expanding out to an octave or more in bandwidth adjustments, +/-0.5dB can be easily audible from a starting reference point. This is nothing new and matches well understood matters of audibility, hearing sensitivity and realities with real program material.

While yearns for a simple, single measurement plot to which then can bulldoze flat, the reality is that audible equivalence or similarity varies every time the decay vs frequency changes in the room, which is complicated further in being a 4D problem most often visualized in 2D or 3D.

(I"m not singling out Mark or RMK! in my below, I'm just pointing out the context of my question.)

Allow me to remind several repeat antagonists that it was RMK! and Mark Seaton who first broached this subject. If one has claims of thread hijacking, they should direct their complaints to Mark and RMK!

As to my abilities, they don't include the ability to mentally visualize naturally occurring standing waves, accompanying corresponding harmonics or to presuppose small sonic niggles. Nor do I know to what level humans are sensitive to small sonic niggles such as the ones I described. If you don't have an answer, please stop being unnecessarily disruptive to the thread. The question is a legitimate follow on question to a comment made by another forum poster and addressed by Mark himself.

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Edited by BeeMan458 - 1/29/13 at 4:36am
point of order

move on please, and limit posts to technical issues

if you see a problematic post, please report it to mods to handle: do not quote it or respond to it

TIA
To add to Mark's comments. It might be better if you have questions about room measurements etc, that a separate thread is started to address this discussion vs derailing this thread dedicated to a specific subwoofer company.
Quote:
Originally Posted by BeeMan458

Thanks.

I did some quick math and the first example is 10% the width of the centered 43Hz octave and the second example is 15% of the width of the centered 73Hz octave. Is either sufficient to degrade the overall sound quality or are they so small that they don't degrade the sound quality; much in the same fashion that in the <120Hz range, THD distortion can hit 10% before it becomes noticeable? That sort of thing?

-

Whether a particular frequency deviation is audible depends on a lot of factors, including what it is you're listening to. IIRC, it's easier to hear narrower, shallower deviations with broadband noise than with real program material. Both dips are quite narrow (2 semitones is the widest) and both are pretty shallow. I frankly would not expect to be bothered by it. I wouldn't necessarily expect to achieve superior performance in home-sized rooms. Once you get all your room dimensions over 40 or 50 feet, then you stop being controlled by the room and you have an easier time of getting flat deep into the bass.
I've said it before and I'll say it again, I just LOVE my 2 SubMersives. Same old same old yeah I know, bad luck, they are awesome! Coming up 3 yrs since I got them and never once have they ever failed to put a smile on my face. And as always still looking forward to getting the HP versions once available in 240v. Anyway that is all, just thought it a good time to jump in and sing the praises once again of one of the truly great products in this vast HT world.
Quote:
Originally Posted by JHAz

Whether a particular frequency deviation is audible depends on a lot of factors, including what it is you're listening to. IIRC, it's easier to hear narrower, shallower deviations with broadband noise than with real program material. Both dips are quite narrow (2 semitones is the widest) and both are pretty shallow. I frankly would not expect to be bothered by it. I wouldn't necessarily expect to achieve superior performance in home-sized rooms. Once you get all your room dimensions over 40 or 50 feet, then you stop being controlled by the room and you have an easier time of getting flat deep into the bass.
I think it's important to differentiate between peaks and dips. Peaks are fairly easy to hear and identify. Dips are far harder. Peaks are excessive energy at a specific frequency range. This peak would be very easy to hear as a boomy, one-note sound:

The fact that it hangs around in the room for a very long time would make it even easier to notice and identify:

OTOH, dips are diminished energy at a specific frequency range. It's much easier to notice and identify something that is too much than to notice and identify something that is *missing*. Still, if the missing energy spans a broad enough frequency range, it is clearly noticeable.

Here is a graph that shows an easily noticeable deficit of the frequency response, as well as a correction of that response:

The difference in the sound between these two graphs was night and day. The graph with the huge, 20 dB dip from 63 to 125 Hz sounded lifeless, weak and thin. The trace where the dip is corrected sounded full, and solid and powerful. (The only adjustment made between these two graphs was an adjustment of the subwoofer Distance setting in the pre/pro.)

Here is another graph that shows the results of the same type of adjustment in another system:

Again, the only change made between the two graphs was a change to the subwoofer Distance setting in the receiver. In this case the difference in sound between the two graphs was more subtle, but still easily noticeable. The corrected graph sounded more powerful.

What would be much harder to discern is a steep, deep null over a very narrow frequency band width. Something like this:

That narrow, steep null at about 260 Hz would only be seen on a high resolution, unsmoothed measurement. It would only be heard, (technically, the better definition is that it would "not be heard") on content at exactly that frequency range. It would be impossible to identify such a null with your ears only. High resolution, unsmoothed measurements would be required to identify this null. In fact, in measurements at other locations in the room, it would show up as a peak in the response.

Correcting such an acoustic problem would best be accomplished with bass traps. EQ would be tough at a 260 Hz frequency. More importantly, it is impossible to EQ out a null. Adding energy, (boost) to a true null just increases the energy cancellation at the null location. Adding boost to try to eliminate the null will also add energy at room locations were the null is a peak, making those locations WORSE. The only effective treatment for this problem is to absorb the offending waves, so you have no reflections, and no corresponding peaks and nulls.

To get back "on-topic, I will agree with crazy4daisy and say that I too LOVE my Submersives.

Craig
Quote:
Originally Posted by craig john

<Snip>
To get back "on-topic, I will agree with crazy4daisy and say that I too LOVE my Submersives.

Craig

I an not exactly sure what the "on-topic" subject here is, as it has changed over the years.

I am a Seaton owner and got started by purchasing the two SubM's from the fellow that started this thread.
I still own them, (Waiting for the day that I can say that I have the HPi upgrade installed in them)
plus I now own three Cat 12Cs for my LCRs. (I also LOVE all of them)

I really enjoy nice tech talks, (Even if they are "off-topic") as I learn from them.

I like my HP too .
Quote:
Originally Posted by craig john

I think it's important to differentiate between peaks and dips. Peaks are fairly easy to hear and identify. Dips are far harder. Peaks are excessive energy at a specific frequency range. This peak would be very easy to hear as a boomy, one-note sound:

The fact that it hangs around in the room for a very long time would make it even easier to notice and identify:

OTOH, dips are diminished energy at a specific frequency range. It's much easier to notice and identify something that is too much than to notice and identify something that is *missing*. Still, if the missing energy spans a broad enough frequency range, it is clearly noticeable.

Here is a graph that shows an easily noticeable deficit of the frequency response, as well as a correction of that response:

The difference in the sound between these two graphs was night and day. The graph with the huge, 20 dB dip from 63 to 125 Hz sounded lifeless, weak and thin. The trace where the dip is corrected sounded full, and solid and powerful. (The only adjustment made between these two graphs was an adjustment of the subwoofer Distance setting in the pre/pro.)

Here is another graph that shows the results of the same type of adjustment in another system:

Again, the only change made between the two graphs was a change to the subwoofer Distance setting in the receiver. In this case the difference in sound between the two graphs was more subtle, but still easily noticeable. The corrected graph sounded more powerful.

What would be much harder to discern is a steep, deep null over a very narrow frequency band width. Something like this:

That narrow, steep null at about 260 Hz would only be seen on a high resolution, unsmoothed measurement. It would only be heard, (technically, the better definition is that it would "not be heard") on content at exactly that frequency range. It would be impossible to identify such a null with your ears only. High resolution, unsmoothed measurements would be required to identify this null. In fact, in measurements at other locations in the room, it would show up as a peak in the response.

Correcting such an acoustic problem would best be accomplished with bass traps. EQ would be tough at a 260 Hz frequency. More importantly, it is impossible to EQ out a null. Adding energy, (boost) to a true null just increases the energy cancellation at the null location. Adding boost to try to eliminate the null will also add energy at room locations were the null is a peak, making those locations WORSE. The only effective treatment for this problem is to absorb the offending waves, so you have no reflections, and no corresponding peaks and nulls.

To get back "on-topic, I will agree with crazy4daisy and say that I too LOVE my Submersives.

Craig

Thanks. I was so focused on Bee's issues (2 dips) that I forgot to contextualize/limit my coments to dips. I know in my room I found I had to reduce the sub level because a post-EQ peak made instruments sound wrong . . . All better now, though
Quote:
Originally Posted by MIkeDuke

I like my HP too .

Mike, you were the 4th poster in this thread in 2006.

Quote:
Originally Posted by MIkeDuke

I like my HP too .

I like all you guys' Submersives, too! (I don't have one yet, so i live vicariously though ya'll)
Quote:
Originally Posted by hydrotex

Quote:
Originally Posted by MIkeDuke

I like my HP too .

I like all you guys' Submersives, too! (I don't have one yet, so i live vicariously though ya'll)

Despite my love for my SubM, it is up for sale in the classifieds section if anyone is close to NY and looking for a deal on one. If I had the funds and space, I would keep it along with the 18s I have.
Quote:
Originally Posted by hydrotex

Quote:
Originally Posted by MIkeDuke

I like my HP too .

I like all you guys' Submersives, too! (I don't have one yet, so i live vicariously though ya'll)

:)  You will love vicariously enjoying my dual Submersive F2s then :)

Quote:
Originally Posted by calentz

Mike, you were the 4th poster in this thread in 2006.
Well, what can I say. Sometimes I am ground floor kind of guy . Just like I was the second post in the Focal\JM Lab thread . But I do like my HP.
Quote:
Originally Posted by hydrotex

I like all you guys' Submersives, too! (I don't have one yet, so i live vicariously though ya'll)

The key word there is: "yet." Soon you shall....soon you shall....
Hydrotex:

Just give into the "force" of Seatonianism and then you too will be able to introduce yourself as follows: "Hi. My name is Hydrotex and I'm a subaholic".

For optimal setup in this room...

I was thinking of placing the SubMersives in the spots my other subs are located (black boxes at 45 degrees in each corner)

*Leaving the SubMersive amp gain at default on both... Use Program 2 designed for larger rooms and lower htz +/-3db... And just run Audyssey MultEQ XT32...*

Anything else I'm missing or should do first?

I know to check Audyssey after and make sure it's not -15db on the sub, I will play with the volume controls on the HP after temp calibration and try to get the receiver to 0db after calibration..
Edited by SOWK - 2/9/13 at 6:34pm
Quote:
Originally Posted by SOWK

For optimal setup in this room...

I was thinking of placing the SubMersives in the spots my other subs are located (black boxes at 45 degrees in each corner)

*Leaving the SubMersive amp gain at default on both... Use Program 2 designed for larger rooms and lower htz +/-3db... And just run Audyssey MultEQ XT32...*

Anything else I'm missing or should do first?

I know to check Audyssey after and make sure it's not -15db on the sub, I will play with the volume controls on the HP after temp calibration and try to get the receiver to 0db after calibration..

first off, wow thats a really nice room you have there. its making me drool. as far as placement i would add to try one up front and one in the rear. try it both ways and see which way sounds best and feels best.
Quote:
Originally Posted by SOWK

For optimal setup in this room...

I was thinking of placing the SubMersives in the spots my other subs are located (black boxes at 45 degrees in each corner)

*Leaving the SubMersive amp gain at default on both... Use Program 2 designed for larger rooms and lower htz +/-3db... And just run Audyssey MultEQ XT32...*

Anything else I'm missing or should do first?

I know to check Audyssey after and make sure it's not -15db on the sub, I will play with the volume controls on the HP after temp calibration and try to get the receiver to 0db after calibration..
Well, you could probably just do what you're suggesting and it will "work", but it's not likely to be the most "optimal" setup for your room.

Mark is only about 90 miles from you. Can you get him to come help you with setup. I know he used to do this for a modest fee. Maybe he still does if it fits his schedule. If you can get him, I'm positive he could tweak a lot more performance out of the subs.

Craig
Quote:
Originally Posted by batt50

try one up front and one in the rear. try it both ways and see which way sounds best and feels best.

You will get more spl with them in the front corners.
Quote:
Originally Posted by Crabalocker

lol!!!!!!! get your mind out of the gutter.
Not sure i'm going to try it in the rear... lol. Sicko's

I was more asking about setup procedures, then location of the subs.

I just want to make sure my steps seem like the correct ones to take and if there was anything else missing left to do?

Steps again:

*Leaving the SubMersive amp gain at default on both... Use Program 2 designed for larger rooms and lower htz +/-3db... And just run Audyssey MultEQ XT32...*

Anything else I'm missing or should do first?

I know to check Audyssey after and make sure it's not -15db on the sub, I will play with the volume controls on the HP after temp calibration and try to get the receiver to 0db after calibration..*

Out of curiosity Craig John... what leads you to beleive the front corners would not be the best location?

It very well might not be. Have you seen a setup similar or heard one like this and was it drastically different?

***Now jumping into positioning a little... Would the HP's work just as good at the same 45 degree angle like in the pics or should I just face them straight out?

As you guys/gals can see I have lots of room behind my screen to move the subs around...

I got one vote for the corners from bsoko2.

Is placing the sub in the main seat and walking around your room for most output still a good way of checking? I haven't done it as I would need a super long cable for the sub...
Edited by SOWK - 2/9/13 at 11:53pm
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