1003 cubic feet 5Hz tuning gotta make history properly - AVS Forum
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post #1 of 127 Old 05-26-2011, 07:50 PM - Thread Starter
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After doing REW sweeps of before the port and after, I realized I was tuned much lower than I thought. Thinking 990 cubic feet realizing 1003 cubic feet (closet door closed, opened it's more like 1040 cubic feet and 4Hz tuning) and from 9Hz to 5Hz, I can't have a title that I can't correct. I have never heard of anyone tuning to 5Hz before, or venting a 1000 plus cubic foot room. So I will leave the build log, post some final pics and REW snapshots in here, and of course now I will do some 5Hz and 6Hz sine waves and distortion plots.... as WinISD shows a VERY narrow SPL increase at tuning, so my 7Hz and 8Hz were out of the port passband giant peak.

Thank you Thomas for pointing it out!

[quote author=admin board=projects thread=1720 post=23531 time=1306460680][quote author=kryptonitewhite board=projects thread=1720 post=23527 time=1306442715]Final tuning appears to be 6.5Hz[/quote]

Unless the laws of physics have changed the tuning is between 9Hz-10Hz. And even that's doubtful because a Radio Shack SPL meter is not accurate test device.[/quote]

Actually, Thomas, if the laws of physics have NOT changed, I am tuned to 5.26Hz. And upon further inspection of the before/after ported plots, it looks like that is correct, more like 5-6Hz, kind sir.

room is 9'5" x 12'5" x 8'7" for 1003 cubic feet
port is 21.5 x 8.5 22"long



Thanks


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post #2 of 127 Old 05-26-2011, 08:20 PM - Thread Starter
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BTW, the reason I started with an 8Hz-9Hz guestimate and made it clear we would see, was I initially plotted with the manifold stopping at the subs and simply cutting the door panels out for ports which would have been 2 x 18.25"x8.25" ports 1.5" thick door, .75" MDF, about 2.25" port length. I decided to run the manifold sides all the way down for more strength to support all that weight and to keep the rear wave from simply canceling out the front wave with no port blockage. That left me with the option of putting 2 divider ports for the two insode port walls, making for 2 x 8.25"x18.25" ports 22" long for about a 7Hz-8Hz tune.

I decided on the final option, 1 giant port, 5Hz tune.
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post #3 of 127 Old 05-26-2011, 09:11 PM
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There is someone on HTS that blocked off their IB to keep the bass from radiating throughout the ceiling and into the rest of the house. They then added a large port, tuned to around 5hz and their spawned the SLLT name for Structural LLT.

My first thought, why not turn two of those drivers around a'la push/pull?
My second thought, why not just remove the door and build an enclosure into the door way?

*Edit* So "kryptonitewhite" was banned at HTS and so you made "Andrew Mason"?

YID DIY
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post #4 of 127 Old 05-26-2011, 09:21 PM - Thread Starter
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THATS MORE LIKE IT! I did a 5.5Hz tone and the whole house wobbles, ceiling wobbles, fan, the paper in the port actually moves. 7Hz is way too high with this narrow of a peak. 95dB at 8%THD and 104dB @ 31% THD



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post #5 of 127 Old 05-26-2011, 09:40 PM - Thread Starter
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im tuned to 5Hz thats all

http://www.youtube.com/watch?v=A24HBlWTGAE

5Hz makes the HOUSE wobble! Now the port blows air!

http://www.youtube.com/watch?v=Ll-ek2wu2Uo
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post #6 of 127 Old 05-26-2011, 09:42 PM - Thread Starter
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Quote:
Originally Posted by Looneybomber View Post

There is someone on HTS that blocked off their IB to keep the bass from radiating throughout the ceiling and into the rest of the house. They then added a large port, tuned to around 5hz and their spawned the SLLT name for Structural LLT.

My first thought, why not turn two of those drivers around a'la push/pull?
My second thought, why not just remove the door and build an enclosure into the door way?

*Edit* So "kryptonitewhite" was banned at HTS and so you made "Andrew Mason"?

Rodney did block off his IB, but that brought his down to 35 cubic feet. Nothing to sneeze at, but still just a regular LLT to me unless it was a 5Hz tuning. I remember coments of F'ing Irene sceen being much better than when it was IB so sounds credible.

Scott's 2 towers are 25 cubic feet each tuned to 11Hz. LLT/EBS.
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post #7 of 127 Old 05-26-2011, 10:00 PM
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Quote:
Originally Posted by kryptonitewhite View Post

Rodney did block off his IB, but that brought his down to 35 cubic feet. Nothing to sneeze at, but still just a regular LLT to me unless it was a 5Hz tuning. I remember coments of F'ing Irene sceen being much better than when it was IB so sounds credible.

Scott's 2 towers are 25 cubic feet each tuned to 11Hz. LLT/EBS.

I've got old age setting in. I would have sworn it was a room sized cavity and not a measly 35ft.

YID DIY
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post #8 of 127 Old 05-26-2011, 10:23 PM
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Yep! saw the ceiling defo move mate. Great result. I wish I had a spare room now.
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post #9 of 127 Old 05-26-2011, 10:37 PM
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Maybe if you brace your ceiling you'll get more SPL down low
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post #10 of 127 Old 05-26-2011, 11:28 PM - Thread Starter
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Looney, 35 cubes isn't measily! My first IB3 18 was in 21.5 tuned to 15Hz when I felt those semis in the WOTWs intro... tomorrow I will see if the flutter scene in HULK is back.

Graham, I watched it, finally! You can see that damned ceiling go! I was thinking everyone was beginning to think I was just lyin back during the towers

notnyt: **** man, you were totally right about so many things. The towers flopped around. Buzzed, rattled, lost so much SPL from flex. Unloaded on 5Hz-9Hz, though I still say I felt it, it was weak, very weak, compared to now. WOTWs has twice as much content and all of it is as strong as the towers or stronger. Lots of it is stronger. I talked a lot of smack to you, but you kept pushing me, and your a big reason why I said "alright. Alright ****er. Ill cut them bitches down and port my damn room and tune to 5Hz. Let notnyt say I am unloading now!"

Thank you for pushing me. I am more than happy!
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post #11 of 127 Old 05-26-2011, 11:29 PM - Thread Starter
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oh, and YES, I need to stick these 2x4s to the ceiling and brace to the bed...floor to ceiling...and I do need to make the 2x4 frame all around the door with weather stripping. How the hell is 5Hz going to push air through door cracks... and rushingly so? Its so slow!
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post #12 of 127 Old 05-27-2011, 12:02 AM - Thread Starter
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A few things that Ive been thinking, 1st is IB localization: be careful. Mine are centered right behind me so its not an issue, but if I had these to one side, it would drive me insane. I can clearly hear the mid/highs directionality. As for ULF, it comes at you from everywhere especially up from under you...no worries there.

People complaining about ports. Group delay. Coloration. Artifacts. I have aquired the opposite misconception. I hate the sound that does not come from the port. As soon as I cut that hole, it came alive. Musically more than anything. When I plugged the towers, it was bad. Not as noticeable because I should have braced the snot out of them.

Group delay? If thats the best you got...ok you can have it. That Bethoven track with cannon shots? Tom Danleys Fireworks? Let me tell you something about a kick in the chest yet that deep low soft fluffy gooey shock wave thats 4 times stronger in my room than in person....at the same time. Hard kick/punch/bang/POW! Mixed with that 7Hz onslought of viscous air. You don't hear the little cubes play the "bang" from 80Hz on up with the subs playing that 20Hz on up, then a split second later the ULF from the port hits you. The lightening in WOTWs does not show a flash then one mississippi two mississippi three mississipppp.... shock wave, like in real life. That **** is THERE.


So whateve on the ports sound bad gig.

The new enclosure shows 500ms!! Towers showed 103ms! Gimme a BREAK!

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post #13 of 127 Old 05-27-2011, 12:27 AM - Thread Starter
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So I've been silently waiting for feedback on the EQ, now I will just ask. Looks like it goes down to 20Hz, so can I EQ Down everything, efectively boosting sub20Hz material? WinISD shows a huge spike in excursion at 15Hz, so hopefully EQing down at 20Hz, 25Hz, ETC will bring down 15Hz but not 10Hz as much, and not 5Hz at all, therefor acting like a boost at 5Hz?


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post #14 of 127 Old 05-27-2011, 10:21 AM
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Where exactly are your measurements taken from?

What do you actually want to achieve wrt EQ? what you're saying is creating a 20hz low pass,...correct? Then, via subsequent gain, you'll boost drive level back up to normalize, thereby essentially boosting 15hz and below?

IMO, bad idea. But try it if you want.

That notch at 41hz, you're not likely to help much there unless you move the LP (or measurement location) significantly. That peak just before the cross could be tamed somewhat, unless it suppresses a kick in the chest that you like. for me, that freq is a bit lower,...65 or so. Actually, your native response at the LP (right?) doesn't appear too bad. Before you get to crazy w/Eq, I'd knock down any resonant issues, buzzes etc, within the room.

btw, Thomas has a good tutorial on the BFD

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post #15 of 127 Old 05-27-2011, 10:57 AM - Thread Starter
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Quote:
Originally Posted by FOH View Post

Where exactly are your measurements taken from?

What do you actually want to achieve wrt EQ? what you're saying is creating a 20hz low pass,...correct? Then, via subsequent gain, you'll boost drive level back up to normalize, thereby essentially boosting 15hz and below?

IMO, bad idea. But try it if you want.

That notch at 41hz, you're not likely to help much there unless you move the LP (or measurement location) significantly. That peak just before the cross could be tamed somewhat, unless it suppresses a kick in the chest that you like. for me, that freq is a bit lower,...65 or so. Actually, your native response at the LP (right?) doesn't appear too bad. Before you get to crazy w/Eq, I'd knock down any resonant issues, buzzes etc, within the room.

btw, Thomas has a good tutorial on the BFD


I am using the same mic stand that I built so hte only thing that changed is th whole bed being moved after taking the towers down. Yes, a 20Hz LP but also a 55Hz HP as well, I want an exaggerated U shape...but that "sweet" dip from 27Hz-45Hz did it for me naturally, but I still want to boost below 15Hz (If I could boost 5Hz and 10Hz I'd be golden).I do like that peak, maybe I will EQ up 65Hz to extend it lower, or 55Hz as you say? Knock down some room issues? like this???




whoa baby! Braced that ceiling....

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post #16 of 127 Old 05-27-2011, 11:45 AM - Thread Starter
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THD tests 1 by 1



bass i love you ceiling fan bracing

http://www.youtube.com/watch?v=XpIfBpaBqus

Virtual Thunderstorm

http://www.youtube.com/watch?v=kgE7G2VMnyM
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post #17 of 127 Old 05-27-2011, 12:48 PM - Thread Starter
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3Hz-5Hz, pretty amazing
The lowest SPL with no distortion reading is 3Hz, the 79dB no read out is 3.5Hz
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post #18 of 127 Old 05-27-2011, 01:42 PM
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wow you actually braced your ceiling, and I was only joking.

Remember when I suggested just turning your room into a speaker enclosure? Looks like you finally did.
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post #19 of 127 Old 05-27-2011, 02:03 PM
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All you need to do now is stuff your room with pillows or should I dare say... pink insulation.
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post #20 of 127 Old 05-27-2011, 02:57 PM
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This extension would make me examine all signal path gear, wrt frequency responses. Just taking this to the next logical step. If every component was solidly flat to near DC, then what's the problem? Where is the rest of it? You're tight with the dudes at Fi, find out if they're the issue. Measure each segment prior to the drives, determine which component is the greatest offender.

The Behringer MIC2200 has a 10hz corner freq, and the two channels of it a daisy-chain-able. Don't you have a Denon AVR?

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post #21 of 127 Old 05-27-2011, 03:18 PM
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I don't mean to jack the thread, but...

I haven't gotten to REW V5 THD measurements specifics yet, but I have been noticing folks posting their results using this program and there's something consistent with all of them that maybe someone can help me with:



Why does the posted THD number never equal the sum of 2HD thru 9HD?

Thanks, and sorry for the diversion, KW,

Bosso
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post #22 of 127 Old 05-27-2011, 03:37 PM
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The harmonics don't add together in a simple linear manner. The same as when you add multiple sound sources together. When you add the harmonics together you would actually add up the total sound energy of the harmonics to be subtracted as a percentage of the strength of the fundamental spl. THD is the sum total percentage of the signal strength that is not comprised ofbthe fundamental. Hope I made some sense there...
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post #23 of 127 Old 05-27-2011, 03:38 PM
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This is a truly unique build

I really like the bracing
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post #24 of 127 Old 05-27-2011, 03:44 PM - Thread Starter
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Quote:
Originally Posted by notnyt View Post

wow you actually braced your ceiling, and I was only joking.

Remember when I suggested just turning your room into a speaker enclosure? Looks like you finally did.

From now on I'm just gonna do what you say and stop pissing around, aight?
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post #25 of 127 Old 05-27-2011, 03:45 PM - Thread Starter
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Quote:
Originally Posted by Mrkazador View Post

All you need to do now is stuff your room with pillows or should I dare say... pink insulation.

back when I 1st started the towers build I took a pic of the walmart $5 pillows and said "so 150 pillows per tower, 300 total, $1800 with tax" :-P

Quote:
Originally Posted by FOH View Post

This extension would make me examine all signal path gear, wrt frequency responses. Just taking this to the next logical step. If every component was solidly flat to near DC, then what's the problem? Where is the rest of it? You're tight with the dudes at Fi, find out if they're the issue. Measure each segment prior to the drives, determine which component is the greatest offender.

The Behringer MIC2200 has a 10hz corner freq, and the two channels of it a daisy-chain-able. Don't you have a Denon AVR?

FOH dude, off the top of my head: Every time you cut down 1 octave you have to move 4X the air. To move 4X the air, you need 4X the cone area or 4X the excursion or a balance of the two. More power. Morte compression. More illiniarity. More vibration loss.... the fact that it even measured distortion and dB at 4Hz amazes me. How is the wave in the air going to push the paper of the microphone diaphram? Im gonna call this good

IDK about Fi and I being tight, ever since the redid the line up Scott and I have been strained. I emailed him again a few days ago asking if I can just paypal him the $$$ for recones when I have it, how much will it be, no reply. Usually I get replies from him pretty quick. I think I hurt them a little with all the car audio kiddie phone calls
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post #26 of 127 Old 05-27-2011, 03:50 PM - Thread Starter
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Quote:
Originally Posted by bossobass View Post

I don't mean to jack the thread, but...

I haven't gotten to REW V5 THD measurements specifics yet, but I have been noticing folks posting their results using this program and there's something consistent with all of them that maybe someone can help me with:



Why does the posted THD number never equal the sum of 2HD thru 9HD?

Thanks, and sorry for the diversion, KW,

Bosso

Bosso, post away. I have huge respect for you so do what you've got to do.


Quote:
Originally Posted by Ricci View Post

The harmonics don't add together in a simple linear manner. The same as when you add multiple sound sources together. When you add the harmonics together you would actually add up the total sound energy of the harmonics to be subtracted as a percentage of the strength of the fundamental spl. THD is the sum total percentage of the signal strength that is not comprised ofbthe fundamental. Hope I made some sense there...

I have no idea what Josh just said, but I have huge respect for this guy too.
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post #27 of 127 Old 05-27-2011, 03:52 PM - Thread Starter
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Quote:
Originally Posted by tuxedocivic View Post

This is a truly unique build

I really like the bracing

thanks for posting tux! Are you more of a lurker, not a big poster? It's always the quiet ones...
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post #28 of 127 Old 05-27-2011, 03:58 PM
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Quote:
Originally Posted by kryptonitewhite View Post

thanks for posting tux! Are you more of a lurker, not a big poster? It's always the quiet ones...

Definetely more of a lurker than you

But I'm not really into the massive bass kind of thing. I'm into DIY speakers moreso than subs. And budget building, tight on funds. But your build is just stupidly insane. Anyone can tell you love bass when you convert realestate into a bass making machine
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post #29 of 127 Old 05-27-2011, 04:04 PM - Thread Starter
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Quote:
Originally Posted by tuxedocivic View Post

Definetely more of a lurker than you

But I'm not really into the massive bass kind of thing. I'm into DIY speakers moreso than subs. And budget building, tight on funds. But your build is just stupidly insane. Anyone can tell you love bass when you convert realestate into a bass making machine

What ya tryin to say, I am a post whore? What do you think of the van front stage? Better than my HT cubes at least :-P I myself am tight on funds as well...had a pile of money for a minute and did both builds (including realestate and van both purchased to litterally house the stereos)

[quote author=chrisbee board=projects thread=1734 post=23547 time=1306529569]The criticism that are using a distinctly inadequate "test microphone" has already been flagged. REW's cal file for the Shack SPL meter runs out of steam an octave or more above your target frequencies. The correction factor as you sink below 10Hz is huge! It might reasonably be suggested that you are testing with a micrometer dangling from the end of a piece of string. (US: length of cord?)

The guys who calibrate microphones for a living might also argue that your tests have no validity. Do you have any friends (left) who might lend you a professionally calibrated microphone and preamp just long enough to confirm your results?

[/quote]


As I gained a few more harsh critics recently such as yourself, I have gained a lot more fans. I am not saying Ricci, notnyt, or Bosso are fans by any means, but their posts alone make the coments of no longer having any friends roll off my back (unless maybe you meant my bass irritating neighbors? In which case I apologize)

At any rate youre not telling me anything I don't know. I know the mic rolls off. I know the results arent solid. You seem to not get that while you sit there and look over everything with a fine tooth comb, I dont care that much about specifics. It is all general to me.

This I know for fact: When I measured the towers then measured IB then measured current ported then measured windows sealed up then ceiling braced, I am NOT claiming the numbers themselves are accurate. I know for a fact that I gained below 10Hz going IB, then I gained below 10Hz by porting it, then I gained below 10Hz by boarding up the windows, then I gained below 10Hz by bracing the ceiling... how much exactly? IDK, but the invalid sub 10Hz testing is an indicator.

fine tooth comb away, knock yourself out!
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post #30 of 127 Old 05-27-2011, 04:27 PM
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Quote:
Originally Posted by Ricci View Post

The harmonics don't add together in a simple linear manner. The same as when you add multiple sound sources together. When you add the harmonics together you would actually add up the total sound energy of the harmonics to be subtracted as a percentage of the strength of the fundamental spl. THD is the sum total percentage of the signal strength that is not comprised ofbthe fundamental. Hope I made some sense there...

I see, but REW calculates them separately against the fundamental as though each harmonic were the only one?

Bosso:
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