Official JTR Speakers Subwoofer Thread - Page 108 - AVS Forum | Home Theater Discussions And Reviews
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post #3211 of 13213 Old 05-01-2017, 07:27 PM
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Originally Posted by cannga View Post
Please also check the first 3 posts of this thread - lots of info about JTR. IMHO it's also helpful to read about CEA-2010 testing in third post to understand JTR subwoofers. The 2400 is a recent JTR release, the middle brother of the series of 3 similar-in-concept JTR subwoofers that use among the most powerful 18 inch driver currently in use: JTR 1400, JTR 2400 ULF, and JTR 4000 ULF. The 3 have different tuning frequencies: 1400 Fb is 17 Hz, 2400 is 14 Hz, and 4000 is 10 Hz. The ULF stands for ultra low frequency, reflecting extremely high performance in sub 20 Hz freq.

The 3 shares 3 parameters that are critical to subwoofer performance: big cabinet, big amp, big driver. Performance + size + price increase as you move up: the 1400 is traditionally shaped, the 2400 is 20x20x40 deep, and 4000 is 20 wide 40 deep 40 high (very big).

That 40" depth dimension has brought concerns regarding difficulty in placement by potential customers (although it's actually best to turn this subwoofer sideways - think of this subwoofer as a 20 inch deep, 40 wide subwoofer) so @Jeff Permanian is contemplating a tall but shallow version of the 2400 ULF: 20x20 footprint, 40 inch high. In either form, it promises to have among the highest performance metrics ever measured for 18 inch ported subwoofer from ID companies, hence all the excitement. Mike Thomas and I are among the many in love .
Thanks for sharing, will do some more reading. I have almost 35 years of experience with pro gear and the move to subs about 20 years ago but just getting my head around the changes in HT application; big differences in how the theory is applied in a couple of short throw tuned cabinets vs array support I am used to.

One question I do have that I haven't seen on here relates to coupling; in a typical concert setup we use coupling (subs centered in clusters to pickup 6 db), has anyone experimented with this concept in HT? It seems most setups I see have the subs separated aligned more in a "stereo" arrangement with the towers....why not couple and get the gain? It does cause timing issues but even in a very big venue we are typically only running about a 13 ms delay to correct for frequency response...any comments or experience with this in HT? I am debating about moving one of my DBX Pros [EDIT: should be clearer as not everyone knows them by this name...DBX PA+] from the studio to the HT to work on the delay and add the benefit of the active x-over and band passes etc. Given the relatively small size of HT and the height proximity of towers vs subs I can't see introducing any comb filtering to have to deal with taking this approach...thoughts?

EDIT 2: I reread this; I should have been clearer that 50% of the coupling effect pickup is because of setting them up on the floor vs the stage at height which we already do in a HT setup...so the potential pickup of moving them together is 3 db not 6....sorry for any confusion (or maybe false excitement for fellow BH is a better way to put it )
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Last edited by Vette_Killer; 05-02-2017 at 05:34 AM. Reason: Added clarity on DBX unit & clarity on coupling
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post #3212 of 13213 Old 05-01-2017, 07:52 PM - Thread Starter
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Originally Posted by Last Mile View Post
Can't wait to test these out and see how they sound.
Nice! My DTS 2016 is coming, DTS 2017 from our friend in Thailand is pending. I hear great things about these DTS demo Blu-rays.
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post #3213 of 13213 Old 05-01-2017, 07:57 PM
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Originally Posted by Marc Alexander View Post
What MV do you normally listen? I think the 1400 will be just fine at [email protected] levels.
Don't forget the 2017 Cap 1400 has a enlarged slot port and improved driver...so more then likely will reduce potential chuffing.
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post #3214 of 13213 Old 05-01-2017, 07:59 PM
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Originally Posted by cannga View Post
BTW outside of the guys having extreme fun pushing wind which I have no criticism of, feeling very noticeable wind in the port might be good for tactile response but is not necessarily a good idea, and a sign that you should add a second subwoofer. Excess wind means you are pushing the subwoofer to its own limit and are that much closer to turbulent, instead of laminar flow (any ex Chem E or ME majors here? :-)) in the port. Turbulent flow leads to port compression, causing output of port to be out of phase with driver, and chuffing. Neither is good for sound.

This is why people with two PB16's are much less likely to hear chuffing than single PB16 (less port wind). A good subwoofer system should always be "loafing" :-) without excessive port wind, implying dynamic headroom.
So if you feel anything coming from the ports it is time for another sub?
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post #3215 of 13213 Old 05-01-2017, 07:59 PM - Thread Starter
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Originally Posted by Adamg (Ret-Navy) View Post
Hi Can,

Sounds like a great line up! Not familiar with the Golden Compass, unless that is a some type of back alley porn?

Dredd! Damn I forgot about that movie. I enjoyed it actually. Entertaining. Was that the very FIRST DTS:X Movie ever? If memory serves, I believe it was. Might be the Movie that started my latest AVR upgrade, that led to a TV upgrade, that led to a BluRay UHD Player upgrade, that led to Roku Ultra upgrade, that led to a Sub-woofer upgrade, that might lead to LRC speaker upgrades.....I digress....

Star Wars Rouge One. Went to see this in the Movie Theatres with the Wife. At about the 1/2 way mark we looked at each-other and in our nonverbal comms system we have developed over the decades, agreed were out of here. So we got up and left. Then one day I'm reading a review of Rouge One. The Author was stressing that the movie is full of stuff, character development, secrets, and really takes place before "A New Hope"! Well that was a revelation. I had no clue. He said this is a Movie you need to watch several times to get it. I bought the Bluray, watched it again, in totality! Like it now. Some awesome Bass as well. It is really a fine movie and a big improvement from the first one.

I hope you enjoy these Movies as much as I did.

Me, I am watching the David Gilmor "Remember That Night" Bluray in glorious Dolby TrueHD Surround. I cut me teeth as a young lad listening to Pink Floyd, Led Zep, Rolling Stones. Late 60's, early to late 70's! While David is getting a little Older looking, his performance and musical talents remain as sharp and vibrant as in his Hay day! If you are a Pink loyd fan, this is a MUST have 2 disc set. 5 Stars for Audio and Video.

After this I may crack open Hacksaw Ridge. Not certain. Enjoy your day Can.


I had to look this up: AFAIK it was the first DTS: *Neo* X, not DTS:X. There is indeed a new 4k release, but the 3D codec is Dolby Atmos, not DTS:X. http://www.blu-ray.com/movies/Dredd-4K-Blu-ray/176582/

Had a great movie weekend, make Monday evern worse , but Golden Compass was an absolute dud - surprised that it got 4.75 star for bass. Dredd on the other hand - I love it. And lastly Rogue One: I still can't get over original Star Wars.
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JTR Subwoofer Thread I don't always listen to subwoofers, but when I do, it's JTR :-).

Last edited by cannga; 05-01-2017 at 08:04 PM.
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post #3216 of 13213 Old 05-01-2017, 10:48 PM
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Originally Posted by cannga View Post
Not about Chucky system but could you give me a quick primer on Audyssey: am I reading it right that post Audyssey you *must* run the sub +6 dB hot or thereabout? When you run Audyssey, and then add 6 dB: if you then check with 5.1 test tone, does the subwoofer then read equal SPL (say 75 dB) to LCR, or does it read 81 dB?

In my Casablanca, the sound would be totally out of whack (way too much bass) if I run subwoofer 6 dB hot, let alone 10 dB hot. The best sound (with quite powerful bass) is to run 75 dB all around.
It's all about personal preference. By default Audyssey XT32 w/SubEQ wants to turn on Dynamic EQ and Dynamic Volume by default. I don't use these in my primary room. IME, most prefer adding +3-6dB [minimum] of boost to subs post Audyssey. I don't use YPAO on my Yamahas but I still set a common 0dB reference point and subs +9-10dB. Some movies require me to dial back to +5-6dB or so.

I just received a Denon X4000 to replace my den Yamaha and I am planning to experiment a bit more with dynamic EQ to add some kick to my son's Disney/Nick Jr. shows. He wants as much tactile feel as he can get! Sitting on the sub is favorite seat.
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post #3217 of 13213 Old 05-02-2017, 05:28 AM
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Yes, it's reference level, much louder than my posted SVS PB-16 clip, but I can certainly hear the JTR Captivator 1400 chuffing away on the 15 Hz and 10 Hz EoT tones here…

(Yes, I know you can make any ported sub chuff…)


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post #3218 of 13213 Old 05-02-2017, 07:29 AM
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Originally Posted by gwsat View Post
I apologize for quoting myself but I wanted to follow up my last post by reporting that, even after playing on my FV18s, at -10dB, the demanding LFE in Leon the Professional, Master and Commander, and, most recently, War of the Worlds the subs have handled it all with the greatest of ease. I am pleased and relieved to report that, at least in my experience, EoT is an outlier with frequencies so low, they set off sympathetic vibrations in a multipurpose room.
gwsat,

I really would look at the Fireplace issues. The Fireplace and Flu will begin to operate like a bass pipe organ at 30Hz and down. It could be the problem you are hearing. Try blocking the fireplace off somehow. Get a hunk of Sheetrock or plywood. Block off the Fireplace, then go back to the scenes where you heard problems and see if they have gone away or gotten better. If so, then consider Fireplace doors that can be closed and sealed when watching Movies and such.

I did post some really good links and videos about Fireplaces and Bass resonance problems. Rememebr, all this tweaking and learnig is part of the fun and enjoyment of incorporation those new beasts into you HT. Enjoy the Ride, un,,,er,,,Slide down the Rabbit Hole!

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post #3219 of 13213 Old 05-02-2017, 07:32 AM
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Originally Posted by cannga View Post
Dredd on the other hand - I love it. And lastly Rogue One: I still can't get over original Star Wars.
I have preordered the Dredd UHD HDR Atmos disk. It's scheduled to be released on 6 June. Really looking forward to seeing and hearing it in its new glory. I am boycotting the Rogue One disk for the moment, though, because of Disney's stubborn refusal to release its films in UHD HDR. Arrrrg!

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Originally Posted by kucharsk View Post
Yes, it's reference level, much louder than my posted SVS PB-16 clip, but I can certainly hear the JTR Captivator 1400 chuffing away on the 15 Hz and 10 Hz EoT tones here…

(Yes, I know you can make any ported sub chuff…)
Yep, that's why I posted to one of the bass-head-centric threads that my experience over the past week with my Rythmik FV18s has led me to conclude that the notorious opening scene in EoT is an outlier. Even if it doesn't make your sub(s) chuff, it will make everything in your HT room that isn't nailed down shake, rattle, and roll. Would be interested to learn how a 4000ULF handles it.

HT setup: Sony 75XBR X940D UHD HDR TV; Kaleidescape Strato Movie Server 6 TB and Terra Server 24 TB; Yamaha RX-A3060 AV receiver; Sonamp 2-1 2channel 100W power amp; Crestron Control System; 2 Rythmik FV18 subwoofers, 6 Hsu HB-1 Bookshelf speakers, 1 Hsu HC-1 Center speaker, 4 Focal ICW8 in-ceiling Atmos speakers; Oppo UDP-203 4K HDR BD player. TiVO Bolt 1TB DVR; TiVo Premiere Elite 2 TB DVR; Roku Premiere+; Apple TV 4K
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post #3220 of 13213 Old 05-02-2017, 07:37 AM
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Originally Posted by kucharsk View Post
Yes, it's reference level, much louder than my posted SVS PB-16 clip, but I can certainly hear the JTR Captivator 1400 chuffing away on the 15 Hz and 10 Hz EoT tones here…

(Yes, I know you can make any ported sub chuff…)

JTR Captivator 1400 Chuffing on EoT tones
Holy Overdrive BassMan! Trying to make Chucky jealous are you?

I suspect a touch too much gain in the chain! If it were me, I would take another look at my gain structure. DEQ as well. It looked to me like the Driver was trying its damned best to beak out of Jail (the enclosure). Sooner or later at those levels it will succeed.

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post #3221 of 13213 Old 05-02-2017, 07:39 AM
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Every port will make air noise at some point. For the same tuning frequency, the larger the port than the longer it needs to be and the lower in frequency the port resonances. Right now the Captivator 1400 port has a resonance at 180hz which is about an octave above where it is normally crossed over. If cost and size were no object than there are things that could be done to further reduce port noise.
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post #3222 of 13213 Old 05-02-2017, 07:41 AM
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Originally Posted by gwsat View Post
I have preordered the Dredd UHD HDR Atmos disk. It's scheduled to be released on 6 June. Really looking forward to seeing and hearing it in its new glory. I am boycotting the Rogue One disk for the moment, though, because of Disney's stubborn refusal to release its films in UHD HDR. Arrrrg!



Yep, that's why I posted to one of the bass-head-centric threads that my experience over the past week with my Rythmik FV18s has led me to conclude that the notorious opening scene in EoT is an outlier. Even if it doesn't make your sub(s) chuff, it will make everything in your HT room that isn't nailed down shake, rattle, and roll. Would be interested to learn how a 4000ULF handles it.
You asked. My 2400's coast through that scene. The Bass is incredible and room compressing. But not one iota of port noise. Nor any unwanted noise for that matter. Disclosure: I have measured usable amounts of output down to about 7Hz and ref level stuff at 10hz.

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post #3223 of 13213 Old 05-02-2017, 08:09 AM
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@gwsat ,

Here is the link about room acoustics and Fireplace resonance issues.

https://www.avsforum.com/forum/113-su...l#post51955041

Watch this: No Fireplaces at 3 min mark.


All of theses Acoustic Fields Videos are worth watching. Specially the Dennis Folley Vids. Awesome source of knowledge and room acoustic information.

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post #3224 of 13213 Old 05-02-2017, 08:19 AM
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Originally Posted by cannga View Post
Not about Chucky system but could you give me a quick primer on Audyssey: am I reading it right that post Audyssey you *must* run the sub +6 dB hot or thereabout? When you run Audyssey, and then add 6 dB: if you then check with 5.1 test tone, does the subwoofer then read equal SPL (say 75 dB) to LCR, or does it read 81 dB?

In my Casablanca, the sound would be totally out of whack (way too much bass) if I run subwoofer 6 dB hot, let alone 10 dB hot. The best sound (with quite powerful bass) is to run 75 dB all around.
Can,

If you would please read the guide in my signature you will understand why most people need to increase the bass for below Reference volumes in 5.1 movies after a manual or automated audio system calibration. And, it really has less to do with Audyssey and more to do with listening to 5.1 movies with bass frequencies in equilibrium with those in our normal hearing range from about 400Hz to 4000Hz. That part is entirely a function of the Equal Loudness Contours.

Most people do choose to boost their bass post-Audyssey. And, that is indeed in part because Audyssey has removed bass peaks which exist in virtually every room. When those peaks are removed, all of the bass frequencies can potentially be heard in better equilibrium, but the overall bass may sound comparatively softer as a result. Then, factor in the Equal Loudness Contours, at below Reference listening levels, and the issue of personal preference that Marc alluded to, and we will all probably listen at different volumes with different amounts of bass boost.

One factor that I think doesn't receive enough attention is the sheer variability in human hearing, and in the way that our brains interpret what we hear, both with respect to overall volume and with respect to individual frequencies. It's not just about age-related hearing loss in high frequencies, it is about native differences in hearing throughout the frequency spectrum. Even the Equal Loudness contours are just based on averages. The actual range of human hearing, and the emphasis that we may place on particular frequencies, probably follows the same bell curve that our other senses and attributes do.

All of those factors can influence our listening levels and the amount of bass we choose to hear. Since this issue has come up several times in discussion, I would take it as a personal favor if people would peruse the guide. That was a considerable time investment, and the principles embodied in it apply to any process of automated or manual calibration of an HT system.

Regards,
Mike

GUIDE TO SUBWOOFER CALIBRATION AND BASS PREFERENCES

* The Guide linked above is a comprehensive guide to Audio & HT systems, including:
Speaker placements & Room treatments; HT calibration & Room EQ; Room gain; Bass
Preferences; Subwoofer Buyer's Guide: Sealed/ported; ID subs; Subwoofer placement.
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post #3225 of 13213 Old 05-02-2017, 08:23 AM
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Originally Posted by Adamg (Ret-Navy) View Post
@gwsat ,

Here is the link about room acoustics and Fireplace resonance issues.

https://www.avsforum.com/forum/113-su...l#post51955041

Watch this: No Fireplaces at 3 min mark.

https://youtu.be/6-dOSD1KoNU

All of theses Acoustic Fields Videos are worth watching. Specially the Dennis Folley Vids. Awesome source of knowledge and room acoustic information.
Geez, i failed pretty much everything. Glass/ fireplace/ no equal distance on my mains. Some how it still sounds pretty good. Guess i wouldn't know what i'm missing until i heard the difference.
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post #3226 of 13213 Old 05-02-2017, 08:26 AM
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You asked. My 2400's coast through that scene. The Bass is incredible and room compressing. But not one iota of port noise.
It's important to note that just because a sub doesn't exhibit port noise or bottoming out during that scene, it doesn't mean it is recreating the content accurately. Most ported subs are designed to steeply roll off the response below tune. That being the case, a sub that is designed to ensure the safety of the driver may not exhibit these bad noises...but also isn't accurately replicating the playback material.

The distinction I'm trying to make is that folks should not be confused with "no bad noises during EOT scene" equals "accurate playback".

Sames goes for WOTW, HTTYD, and other clips with high ULF; when folks state "my sub sailed through those scenes with no problem", it doesn't mean that it recreated the content accurately...(e.g. ported subs where single digit output is required).

While I'm responding to adamg's comment, it's more of a general response and not specific to his example.
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post #3227 of 13213 Old 05-02-2017, 08:29 AM
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Originally Posted by dominguez1 View Post
It's important to note that just because a sub doesn't exhibit port noise or bottoming out during that scene, it doesn't mean it is recreating the content accurately. Most ported subs are designed to steeply roll off the response below tune. That being the case, a sub that is designed to ensure the safety of the driver may not exhibit these bad noises...but also isn't accurately replicating the playback material.

The distinction I'm trying to make is that folks should not be confused with "no bad noises during EOT scene" equals "accurate playback".

Sames goes for WOTW, HTTYD, and other clips with high ULF; when folks state "my sub sailed through those scenes with no problem", it doesn't mean that it recreated the content accurately...(e.g. ported subs where single digit output is required).

While I'm responding to adamg's comment, it's more of a general response and not specific to his example.
Hi Dom,

Thanks for picking my post to make that point! What did I ever do to you

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post #3228 of 13213 Old 05-02-2017, 08:30 AM
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Originally Posted by Vette_Killer View Post
Thanks for sharing, will do some more reading. I have almost 35 years of experience with pro gear and the move to subs about 20 years ago but just getting my head around the changes in HT application; big differences in how the theory is applied in a couple of short throw tuned cabinets vs array support I am used to.

One question I do have that I haven't seen on here relates to coupling; in a typical concert setup we use coupling (subs centered in clusters to pickup 6 db), has anyone experimented with this concept in HT? It seems most setups I see have the subs separated aligned more in a "stereo" arrangement with the towers....why not couple and get the gain? It does cause timing issues but even in a very big venue we are typically only running about a 13 ms delay to correct for frequency response...any comments or experience with this in HT? I am debating about moving one of my DBX Pros [EDIT: should be clearer as not everyone knows them by this name...DBX PA+] from the studio to the HT to work on the delay and add the benefit of the active x-over and band passes etc. Given the relatively small size of HT and the height proximity of towers vs subs I can't see introducing any comb filtering to have to deal with taking this approach...thoughts?

EDIT 2: I reread this; I should have been clearer that 50% of the coupling effect pickup is because of setting them up on the floor vs the stage at height which we already do in a HT setup...so the potential pickup of moving them together is 3 db not 6....sorry for any confusion (or maybe false excitement for fellow BH is a better way to put it )
Hi,

A lot of sealed sub setups, especially for owners who frequent the ULF scorecard thread, do just as you suggest with stacks of sealed subwoofers. Seaton Sound, for instance, offers master/slave combos that are specifically designed to be stacked. Mark's avatar shows him standing between two giant stacks of subs.

I think that in a typical HT room, as opposed to a concert venue, a lot of mutual coupling will occur below about 30Hz, irrespective of some sub separation. I also believe that most people with powerful ported subs find more benefit in distributing the subs for the improvement in frequency response, and overall bass envelopment, that generally occurs.

Regards,
Mike
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GUIDE TO SUBWOOFER CALIBRATION AND BASS PREFERENCES

* The Guide linked above is a comprehensive guide to Audio & HT systems, including:
Speaker placements & Room treatments; HT calibration & Room EQ; Room gain; Bass
Preferences; Subwoofer Buyer's Guide: Sealed/ported; ID subs; Subwoofer placement.
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post #3229 of 13213 Old 05-02-2017, 08:38 AM
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Hi Dom,

Thanks for picking my post to make that point! What did I ever do to you

Sorry...wasn't trying to call you out as I mentioned. It just triggered a point that I thought was relevant since the EOT clip is of hot topic lately.

I know @kucharsk 's has been concerned with chuffing, and is weighing a decision on what sub to purchase next...so wanted to get that out there.

Although, I did call out ported subs...the same thing is relevant for sealed subs. Yes, you won't get chuffing, but MFGs typically put in limiters on sealed subs as well. The thing with sealed subs though, you can just keep adding more until it meets your output requirements for accurate playback.
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post #3230 of 13213 Old 05-02-2017, 08:40 AM
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Geez, i failed pretty much everything. Glass/ fireplace/ no equal distance on my mains. Some how it still sounds pretty good. Guess i wouldn't know what i'm missing until i heard the difference.
So did I so your not alone. But knowing is half the battle. Not knowing what you don't know is, well, head sand posture. Learning all this, I was able to address some of my room issues and the improvements were very noticeable. Simple stuff really. Keeping the Curtains closed on my wall of glass. Putting up a small room divider decorative folding wall stand thing. Helped with a small alcove/hallway that was resonating like mad. It still resonates and is a major bass trap, but at about half the previous energy.

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post #3231 of 13213 Old 05-02-2017, 08:42 AM
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So if you feel anything coming from the ports it is time for another sub?
Not necessarily! Air coming from the port at close range is more a function of the listening volume and/or sub boost, than it is a specific indication of sub distress. Jeff and Mark S. made a video at an GTG where a pair of Cap 4000's scooted a baseball cap across the floor. Indications of physical distress from a sub would include clipping some frequencies, port chuffing, and the mechanical sound of the sub hitting its limiter.

So, I would say that it depends. Much air coming from a port probably indicates a sub very close to its limits. But, unless Jeff or someone can better quantify that, I would go with my instincts on the issue. Bad sounds or an impression of a sub near its limits--time for another, or stronger sub. Or both.

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post #3232 of 13213 Old 05-02-2017, 08:58 AM
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@cannga my preferences most closely follow the JBL/Harman curve. I meant to include this chart in my post re: Audyssey yesterday.
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post #3233 of 13213 Old 05-02-2017, 08:59 AM
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One more common misconception (perhaps relevant for @Marc Alexander 's upcoming mini gtg);

Take a sub that is tuned to 15hz and another that is tuned to 20hz.

EOT clip is played on both setups...no bad noises.

"Both listeners state that the 20hz tuned subs felt a lot more tactile! The 20hz sub played that clip much better than the 15hz sub!"

What's likely that is occurring is that the 20hz sub is exhibiting more 2nd order harmonic distortion on those low clips. This means that when the 20hz sub is trying to play the 15hz signal, it's actually reproducing 30hz sounds (2nd order HD to 15hz). Because 30hz is typically more tactile than 15hz, the sub "subjectively" played it better....when in reality, the 15hz sub was more accurate.

FWIW

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post #3234 of 13213 Old 05-02-2017, 09:05 AM
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You asked. My 2400's coast through that scene. The Bass is incredible and room compressing. But not one iota of port noise. Nor any unwanted noise for that matter. Disclosure: I have measured usable amounts of output down to about 7Hz and ref level stuff at 10hz.
Your effective tuning port frequency is the key, I think. My FV18s will play down just fine to their set port tuning frequency of 12Hz but may not much like loud lower frequencies, i.e. EoT. In defense of my FV18s, though, after I got them dialed in, all of the unpleasantness in EoT appeared to have been caused by sympathetic vibrations in my room, not by the subs. Anyway, if EoT turns out to be my only problem child, I can live with it.
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post #3235 of 13213 Old 05-02-2017, 09:24 AM
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Hi Dom,

Thanks for picking my post to make that point! What did I ever do to you

Not sure if your been sarcastic Adamg, but its a good point and just more info to learn for us,,, thats never a bad thing. In your case with two 2400's seven feet from your MLP the roll off may not be so abrupt.
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post #3236 of 13213 Old 05-02-2017, 09:27 AM - Thread Starter
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All very nice discussions.

@Marc Alexander : Like father like son LOL. That young man is getting a early education in all things audio. Thanks for the nice picture.

@4kicknsnd : pls see Mike explanation. All ports will have wind and all will blow hard ;-) when pushed, *all*. What I meant is that if your listening habit results in *excessive* wind in the port most of the time (very unlikely with these big subwoofers unless you are at hearing damage level frequently) then maybe it's time to add a second subwoofer.

Guys playing at GTG, etc. is harmless and not what I have in mind. I'm thinking for example music with synthesized bass at excessive volume - you'll end up a. destroying the subwoofers b. hearing mostly distortion.
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post #3237 of 13213 Old 05-02-2017, 09:50 AM
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Originally Posted by dominguez1 View Post
One more common misconception (perhaps relevant for @Marc Alexander 's upcoming mini gtg);

Take a sub that is tuned to 15hz and another that is tuned to 20hz.

EOT clip is played on both setups...no bad noises.

"Both listeners state that the 20hz tuned subs felt a lot more tactile! The 20hz sub played that clip much better than the 15hz sub!"

What's likely that is occurring is that the 20hz sub is exhibiting more 2nd order harmonic distortion on those low clips. This means that when the 20hz sub is trying to play the 15hz signal, it's actually reproducing 30hz sounds (2nd order HD to 15hz). Because 30hz is typically more tactile than 15hz, the sub "subjectively" played it better....when in reality, the 15hz sub was more accurate.

FWIW
Agree. Here is the HSU Research VTF-15H trying to play 10 Hz and 12.5 Hz. One will hear sound, but it is the harmonic distortion that they are hearing.



Even at 20 Hz, when the sub is pushed to its limits one will most likely hear 40 and 60 Hz as loud or louder when you factor in the equal loudness contour.

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post #3238 of 13213 Old 05-02-2017, 09:50 AM
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Ive tried but never was able to get air velocity much less port noise. I mean I get SO MUCH bass and the drivers never even move. Ive seen them move a few times a little or the bass I love you demoes. I suspect I would need a 20-30 line and get really crazy around the 15hz port tune
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post #3239 of 13213 Old 05-02-2017, 10:13 AM
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Not sure if your been sarcastic Adamg, but its a good point and just more info to learn for us,,, thats never a bad thing. In your case with two 2400's seven feet from your MLP the roll off may not be so abrupt.
IDBF,

How did you miss the in that post? Indicating that I was indeed just joking. Or your pulling my chain now, not sure which!
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post #3240 of 13213 Old 05-02-2017, 10:14 AM - Thread Starter
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Hi Dom,

Thanks for picking my post to make that point! What did I ever do to you


(I do see the smiley. ) Not to worry Adam, in your case with dual 2400's, not hearing bad noise with EOT indeed = accurate playback. :-) Or at least, as accurate as could be. Your dual beasts are truly "loafing."

IMHO, CEA-2010 and EOT, etc., test distortion at max output, but because the relationship between distortion and output is proportional (not linearly so, but perhaps "progressively" so), the subwoofer with highest CEA numbers would have less distortion at sub max level as well.

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