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Here's my estimates for the new RA line. I think these are in the ballpark, but let me know of any tweaking necessary.

 

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^^^Thanks Jeremy. :cool:

Congrats on the new subs...definitely look very promising!
Thank you!

I think you are pretty darn close - leaning towards the conservative side (We're mildly confident Ricci will clock the Echo 18 over 112 @ 20hz, 2m).

But conservative is good.
 
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I downloaded several VM apps and think I found one that'll work. Not knowing the first thing about vibration meters I assume XYZ axis does the trick. This one seems sensitive enough. If this does work out then we will have a VM solution for iPhone users. No more guessing when it comes to tactile response, if it works out.

Last few days I've testing a few things out regarding tactile improvement. I forgot to mentioned that I have rubber isolators that replaced my seating feet. I'm sure this amplifies the tactile response as well. It made a difference before with the seats mounted on concrete. With the sound intensity and PVL being primarily responsible for tactile feedback, I wonder if it's of any benefit having the sub mounted on the riser.

One thing that would be of huge benefit is if we had a database/thread for tactile like what this thread has accomplished. Where a person could go and get the info and product data needed to get the needed or wanted response. Comparisons of passive and active risers/platforms and seating. Explore and find that perfect balance of spl to tactile, for example, at [email protected] is should 5.2vm or whatever the optimal number is and to achieved you have to do this and this. To me tactile is as important as having a sub.
 

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I downloaded several VM apps and think I found one that'll work. Not knowing the first thing about vibration meters I assume XYZ axis does the trick. This one seems sensitive enough. If this does work out then we will have a VM solution for iPhone users. No more guessing when it comes to tactile response, if it works out.

Last few days I've testing a few things out regarding tactile improvement. I forgot to mentioned that I have rubber isolators that replaced my seating feet. I'm sure this amplifies the tactile response as well. It made a difference before with the seats mounted on concrete. With the sound intensity and PVL being primarily responsible for tactile feedback, I wonder if it's of any benefit having the sub mounted on the riser.

One thing that would be of huge benefit is if we had a database/thread for tactile like what this thread has accomplished. Where a person could go and get the info and product data needed to get the needed or wanted response. Comparisons of passive and active risers/platforms and seating. Explore and find that perfect balance of spl to tactile, for example, at [email protected] is should 5.2vm or whatever the optimal number is and to achieved you have to do this and this. To me tactile is as important as having a sub.
+1. I actually tried to start something like this a while back:

http://www.avsforum.com/forum/113-subwoofers-bass-transducers/1398473-measuring-tactile-feeling-your-sub-system.html

The only challenge to this is measuring in the vertical axis. In my room, when placed on my seats (horizontal axis), I get considerable shaking between 10 and 20hz, and not much after that. But what I can tell you is that I also get as much shaking above 20hz...but it's against my back (vertical axis) and not my seat cushions.

The other things that this cannot measure is that 'kick in the chest' feeling, which likely could only be measured via a Sound Intensity meter like the Microflown.

Were you ever able to test how much your riser shakes with your nearfield subs off?
 

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+1. I actually tried to start something like this a while back:

http://www.avsforum.com/forum/113-subwoofers-bass-transducers/1398473-measuring-tactile-feeling-your-sub-system.html

The only challenge to this is measuring in the vertical axis. In my room, when placed on my seats (horizontal axis), I get considerable shaking between 10 and 20hz, and not much after that. But what I can tell you is that I also get as much shaking above 20hz...but it's against my back (vertical axis) and not my seat cushions.

The other things that this cannot measure is that 'kick in the chest' feeling, which likely could only be measured via a Sound Intensity meter like the Microflown.

Were you ever able to test how much your riser shakes with your nearfield subs off?
Not yet but will try that tonight or tomorrow.
 

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Discussion Starter #3,068 (Edited)
V18.2 of the ULF Calculator now available


  • Added new PSA Subs (V1500, S1500, S3000i)
  • Added new RA Subs (Echo 15, Echo 18, Gamma 15, Gamma 18, Gamma 218)
  • New ULF Members @coolrda, @galonzo
  • Updated ULF Members @Ted Sheckler, @derrickdj1
  • Separated the Member ULF Score Data into its own spreadsheet on post 1 (ULF Calculator exceeded upload limits)

Member ULF Stars


Member ULF Scores


Member ULF SI Equivalents


Member Tactile Feedback FX
 

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I downloaded several vibration meter for IOS over the last few days and played around with them. The best of the bunch was one called VibSensor which seems to be a good match for tactile testing. I don't understand all the data yet but I can read a graph. For starters I made runs comparing front only rear only and all subs, taken from the MLP seat and riser floor. I kept levels low for now until I can become comfortable using it. For test material I looked through all my subwoofer test CD's and found a dvd I dl'd from SOHO54. Its a dolby digital test dvd with an LFE track. After spending an hour making test runs then several more reading about what the various data means I think this will be a big help. My sensor is a iPhone 6 plus. I removed the case for the test runs. The LFE tracks are at -20db and I ran the tests at -30db and -20db so the levels were pretty low. However even at the low levels the tests came out fine. Its extremely sensitive. Heres some pics.









 

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The VibSensor takes run from 0.3-50hz. You can take runs from 10 seconds to 5 minutes. It uses three sensors, front to back(Y), top to bottom(Z) and side to side(X) and displays all axis separately and combined. Heres some screen shots of a few runs. I used the 60hz-1hz 30 sec sweep primarily.







Here the blue is the Z axis, the red Y and the green X. Theres been a lot posted about the different characteristics of tactile response, the pulse, the wobble, etc. I experience this playing the first minute or so of the latest Transformers, the extinction scene. The initial pulse followed by the rumble. Its one advantage that a sub has over transducers. Theres never been a good explanation that I've read of whats happening and why they feel different. Playing the 60-1hz sweep notice what happens.

X axis.


Y axis.


Z axis and combined.


Where the Z axis, Blue or top to bottom starts to dominate is about 40hz. Above 40z though the Y axis, red or front to back movement dominates which could be why it feels like a pulse wave as intended. The different characteristics could be frequency dependent.

So those of you with iPhones or iPads, download this and give it a try. The more input and data the better. Looks like I have some homework the next couple weeks. PSD?:eek:
 

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Please give me your comments on weather sealed is better then ported when considering ULF? By going ported dose one miss on ULF? What is your thoughts on what is being missed by going ported? Does it make a difference for you?

How many action/adventure movies have content below 15 hz?

What is your suggestion for my room?

I currently have:
-Sealed and dedicated HT room
-17.5 feet long x 11 feet wide x 7.5 feet high - so about 1400 sq feet
-I sit about 9 feet from my sub
-Currently i have a single sealed Velodyne HGS 15 inch and I believe its db's at 2 m are
10 hz.......... -
12.5 hz....... -
16 hz.......... 89.1
20 hz.......... 94.5

-I like to listen at reference level
-My HT room is acoustically treated. 4" absorbers on side walls and ceilings at first reflection points. Bass absorbers in several of the corners. Floor has carpet on it. My center channel is just below the screen.
-I use my HT for 100% movies
-I do appreciate good bass and like action/adventure movies
 

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It's really a buyer's market when it comes to looking for a good sub. With all the commercial, Internet Direct and DIY options available the performance to cost ratio has never been higher. In the past the recommendation would have been sealed, sealed or sealed. But nowadays with tunable ported sub with on board dsp processing and mega wattage amps, its really a toss up. I think the consensus here is may be to go with two subs, one in each front corner. That will provide good coverage. Then add a third behind you in the nearfield in the future if your taste demand it. If your quest for subwoofage becomes insatiable, You can continue on from there. The current pinnacle of achievement in LF and ULF systems comes by way of the DIY sub systems and arrays that are listed here. The sky is the limit with these mega systems, plus they can be specifically adapted to the room.

You have plenty of data here to compare including size of rooms matching yours. Then establish your short term and long term budget and goals. Two subs should be the absolute minimum here. First goal should be to hit reference at 20hz. With your small room you should do well. Theres a ton of movies with ULF content however brief it may be. I think its a worthwhile pursuit as it adds a foundation, a heavy thick weighty presence to the presentation that once experienced is necessary.
 

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Discussion Starter #3,079
Great stuff, @coolrda. Have an understanding of this is incredibly meaningful IMO, but almost always overlooked. It's tough to have a precise measuring rig for this, but certainly exploring like you and others (@bassthathz) have done helps advancing our collective knowledge base. The trick (at least for me) is making it simple enough to interpret and use to make mainstream so that it's easy to build the overall database that we all can learn from (similar to what I hoped to achieve with the ULF calculator). :cool:

The VibSensor takes run from 0.3-50hz. You can take runs from 10 seconds to 5 minutes.
What do you mean "takes run from .3-50hz"? I can interpret sine waves in this range, but outside of this range it cannot?

If it's just measuring vibrations, why is there a tolerance from a certain frequency range? I guess that also leads to my question in your images below: I see the software references Hz...is that Hz generated by the motion of the phone, or is it somehow recognizing the sweeps your playing?

Just curious how you are interpreting that.

It uses three sensors, front to back(Y), top to bottom(Z) and side to side(X) and displays all axis separately and combined. Heres some screen shots of a few runs. I used the 60hz-1hz 30 sec sweep primarily.





My interpretation of this is that the most movement occurs on the Z axis (side to side). The fronts only recorded an rms value of .14 for Z. The rears recorded an rms value of .26 for Z. The combination recorded a value of .28 for Z for both.

So the combination of the fronts and the rears didn't significantly change the vibration of the rears?

Here the blue is the Z axis, the red Y and the green X. Theres been a lot posted about the different characteristics of tactile response, the pulse, the wobble, etc. I experience this playing the first minute or so of the latest Transformers, the extinction scene. The initial pulse followed by the rumble. Its one advantage that a sub has over transducers. Theres never been a good explanation that I've read of whats happening and why they feel different. Playing the 60-1hz sweep notice what happens.

X axis.


Y axis.


Z axis and combined.


Where the Z axis, Blue or top to bottom starts to dominate is about 40hz. Above 40z though the Y axis, red or front to back movement dominates which could be why it feels like a pulse wave as intended. The different characteristics could be frequency dependent.
I understand what you're trying to demonstrate here. Different frequencies shake the riser in different ways. But the 40hz frequency you referenced, is that in relation to the hz in your images, or is that just the frequency that was excited through your tones?
 

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Great stuff, @coolrda. Have an understanding of this is incredibly meaningful IMO, but almost always overlooked. It's tough to have a precise measuring rig for this, but certainly exploring like you and others (@bassthathz) have done helps advancing our collective knowledge base. The trick (at least for me) is making it simple enough to interpret and use to make mainstream so that it's easy to build the overall database that we all can learn from (similar to what I hoped to achieve with the ULF calculator). :cool:



What do you mean "takes run from .3-50hz"? I can interpret sine waves in this range, but outside of this range it cannot?

If it's just measuring vibrations, why is there a tolerance from a certain frequency range? I guess that also leads to my question in your images below: I see the software references Hz...is that Hz generated by the motion of the phone, or is it somehow recognizing the sweeps your playing?

Just curious how you are interpreting that.


My interpretation of this is that the most movement occurs on the Z axis (side to side). The fronts only recorded an rms value of .14 for Z. The rears recorded an rms value of .26 for Z. The combination recorded a value of .28 for Z for both.

So the combination of the fronts and the rears didn't significantly change the vibration of the rears?



I understand what you're trying to demonstrate here. Different frequencies shake the riser in different ways. But the 40hz frequency you referenced, is that in relation to the hz in your images, or is that just the frequency that was excited through your tones?
Since this was a simple swept tone from 60-1hz I was just guessing as to the frequencies where the Y axis vibration dominated. The Power Spectral Density actually breaks it down better. I'll include the logarithmic PSD too.



 
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