Official JTR Speakers Subwoofer Thread - Page 465 - AVS Forum | Home Theater Discussions And Reviews
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post #13921 of 13951 Old 01-13-2020, 04:43 AM
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Originally Posted by Adamg (Ret-Navy) View Post
Hi @chucky7 ,

I wish to pick your brains, if you will permit Sir?

Background:

A while back in this thread (I'm too lazy this morning to go look it up and quote it) you recommend that prior to running an Audyssey Calibration the user/owner should ajuts the "LF Adjust" Cut or to zero or minimum. I forget the scale but think it is either "Cut" or "Boost"?

Anywho, I have replaced the Rug in my TV room. The new rug is considerably less dense than the previous which was 1 1/2 thick. Therefore I feel I need to rerun Audyssey to compensate for this reduction in absorption.

Question:

May I ask, what is your thinking/rationale here? Why do you recommend the "LF Adjust" be set at "Cut" for a new calibration? Just wish to understand what this does for the Calibration or FR Curve and how this adjustment affects measurements related to Audyssey.

I do understand that Post calibration I can return the "LF Adjust" to its previous REW derived settings.

Thank you Chucky for taking the time to share your JTR Wisdom!
Yes, both toddct and zeus33 have answered your question better than I ever could.

I know Jeff recommends setting the LF Adjust to 1/3 before running automatic room corrections. However, he doesn't run a typical AVR like we do.

Setting the LF Adjust to cut or minimum before running automatic room corrections is Audyssey specific, because we know Audyssey will try to smooth out the FR. Even with the LF Adjust at cut, the low tuned JTR subs are already very extended and there will be some room/boundary gain because people tend to place subs near a wall. My F3 is 10Hz with LFA at cut! The LFA adds around 18dB at the tuning frequency. Therefore, setting the LFA to cut before running Audyssey allows us to still have the full 18dB at our disposal.

And yes, you should rerun Audyssey whenever you feel that you have done something that changed the room acoustics.

You're very welcome!

Speakers: L/C/R: JTR Noesis 212HT. Surrounds: Jamo C103, KEF Q100, Polk Audio RTiA3.
Subwoofer: JTR Captivator 4000ULF.
AVR: Denon AVR-X4400H. TV: Samsung UN75NU8000FXZA.

FS: Jamo C103, KEF Q100 and Polk RTiA3

Last edited by chucky7; 01-13-2020 at 06:17 AM.
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post #13922 of 13951 Old 01-13-2020, 06:00 AM
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@JimWilson you did a review on home theater shack for the JTR RS1 subwoofers. Unfortunately the picture links are all broken, and I can’t see your graphs for measurements. Could you please post your graphs for this sub?

Thanks
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post #13923 of 13951 Old 01-13-2020, 06:05 AM
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Originally Posted by 3fingerbrown View Post
@JimWilson you did a review on home theater shack for the JTR RS1 subwoofers. Unfortunately the picture links are all broken, and I can’t see your graphs for measurements. Could you please post your graphs for this sub?

Thanks
I believe he did one for the S1 not the new RS1

Subwoofers: Dual Rythmik FV18s Rev2 with Paper cone, BOSS Platform mini riser, 2 BK LFE
Speakers: PSA MTM-210 L/C/R - Klipsch 250S Surrounds, PSA MT 110sr Rear Surrounds, 4 x SVS Prime Elevation for Atmos
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post #13924 of 13951 Old 01-13-2020, 06:30 AM
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Originally Posted by 3fingerbrown View Post
@JimWilson you did a review on home theater shack for the JTR RS1 subwoofers. Unfortunately the picture links are all broken, and I can’t see your graphs for measurements. Could you please post your graphs for this sub?

Thanks
Jim did R1's in room FR. He doesn't do compression sweeps.

I do have R1's in house FR:

I have also asked Jeff about the RS1. He said that the RS1's FR has a flatter top end than the Data-Bass tested S2. The RS1's LF Adjust @ cut is -9dB @ 15.5Hz vs @ boost.
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post #13925 of 13951 Old 01-13-2020, 07:23 AM
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Quote:
Originally Posted by chucky7 View Post
Yes, both toddct and zeus33 have answered your question better than I ever could.

I know Jeff recommends setting the LF Adjust to 1/3 before running automatic room corrections. However, he doesn't run a typical AVR like we do.

Setting the LF Adjust to cut or minimum before running automatic room corrections is Audyssey specific, because we know Audyssey will try to smooth out the FR. Even with the LF Adjust at cut, the low tuned JTR subs are already very extended and there will be some room/boundary gain because people tend to place subs near a wall. My F3 is 10Hz with LFA at cut! The LFA adds around 18dB at the tuning frequency. Therefore, setting the LFA to cut before running Audyssey allows us to still have the full 18dB at our disposal.

And yes, you should rerun Audyssey whenever you feel that you have done something that changed the room acoustics.

You're very welcome!
Chucky,

Thanks for the follow up answer my friend. Interesting response. I ran at full cut and will live with it for a while.

I did notice I have gobs of head room now compared to previous cal where I ran Cal @ LFA at 9 out of 10 on both subs. After Aud level matching I got -10 and -9.5. About where I try to get. But last time (with LFA at 9 during Cal) I increased gain to 11 of 20 on each sub and AVR sub trims down to -7 on each. This time (LFA on 0 or Cut) I was only able to raise gain to 9 of 20 and AVR trims at -11 & -10.5 and I am thinking of dialing the Sub gain down another notch. As the Subs are much louder now and I have little trim left to go down in the AVR Sub trim. LFA Post cal was set back to 9 of 10 on both.

So running LFA on Cut definitely gave me back considerable Gain (head room) Post Audyssey Calibration. I am still amazed by these Subs. The sheer horsepower these goliaths dispense in my very large room on concrete is astonishing.

Reminds me of the "Jack in the Box" scene in the Movie "Elf"
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post #13926 of 13951 Old 01-13-2020, 09:59 AM
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Quote:
Originally Posted by chucky7 View Post
Yes, both toddct and zeus33 have answered your question better than I ever could.

I know Jeff recommends setting the LF Adjust to 1/3 before running automatic room corrections. However, he doesn't run a typical AVR like we do.

Setting the LF Adjust to cut or minimum before running automatic room corrections is Audyssey specific, because we know Audyssey will try to smooth out the FR. Even with the LF Adjust at cut, the low tuned JTR subs are already very extended and there will be some room/boundary gain because people tend to place subs near a wall. My F3 is 10Hz with LFA at cut! The LFA adds around 18dB at the tuning frequency. Therefore, setting the LFA to cut before running Audyssey allows us to still have the full 18dB at our disposal.

And yes, you should rerun Audyssey whenever you feel that you have done something that changed the room acoustics.

You're very welcome!
Most people end up at 1/4 - 1/3 of the LF Adjust with the sealed subs for a flat response in room (ported 0 - 1/4). However, seems that when using auto room correction, people have getting the best results from having the LF adjust all the way down and then turning it up after room correction. Because subwoofers typically have higher max output on the topend vs the lowend, you end up with increased head room with lower LF Adjust.
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post #13927 of 13951 Old 01-13-2020, 10:20 AM
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Quote:
Originally Posted by Adamg (Ret-Navy) View Post
Chucky,

Thanks for the follow up answer my friend. Interesting response. I ran at full cut and will live with it for a while.

I did notice I have gobs of head room now compared to previous cal where I ran Cal @ LFA at 9 out of 10 on both subs. After Aud level matching I got -10 and -9.5. About where I try to get. But last time (with LFA at 9 during Cal) I increased gain to 11 of 20 on each sub and AVR sub trims down to -7 on each. This time (LFA on 0 or Cut) I was only able to raise gain to 9 of 20 and AVR trims at -11 & -10.5 and I am thinking of dialing the Sub gain down another notch. As the Subs are much louder now and I have little trim left to go down in the AVR Sub trim. LFA Post cal was set back to 9 of 10 on both.

So running LFA on Cut definitely gave me back considerable Gain (head room) Post Audyssey Calibration. I am still amazed by these Subs. The sheer horsepower these goliaths dispense in my very large room on concrete is astonishing.

Reminds me of the "Jack in the Box" scene in the Movie "Elf"
Adam,

You're welcome!

In your previous setting (with LFA @ 9 during Audy calibration, and LFA @ 9 after), Audy basically neutered a lot of output below 25Hz at the same MV. I believe you probably don't even need to run LFA @ more than half way now to be at where you were before, and your door and ground should shake more with the LFA above half way.

Movies such as Aquaman and Hunter Killer should be scarier now...
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Subwoofer: JTR Captivator 4000ULF.
AVR: Denon AVR-X4400H. TV: Samsung UN75NU8000FXZA.

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post #13928 of 13951 Old 01-13-2020, 10:37 AM
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I have today off so I was able to do some more testing. I have completed a set of compression tests of the JTR 1200xs solo. The JTR resides about 11-12ft from the MLP. I use this location for my third sub placement as it has the best low end response which compliments my nearfield subs. The sweeps are taken post Audyssey correction.

This first set of measurements is with the LFA set mid(12:00), then adjusted max. This applies a ton of boost down low. I run out of headroom around MV -5 with the sub trim boosted 5db. I can also hear some brief vent noise.


The second set of measurements is with LFA set mid and left mid post calibration. I was able to run the volume up to +2 and THD eclipsed 11%. Some of that could be being picked up by rattles and room vibrations. At the MV-0 sweep THD was 8%. Not bad at all really and this sub was able to achieve almost 106db @ 10hz. Also there was very little vent noise on the highest sweep.
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post #13929 of 13951 Old 01-13-2020, 10:47 AM
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Originally Posted by basshead81 View Post
I have today off so I was able to do some more testing. I have completed a set of compression tests of the JTR 1200xs solo. The JTR resides about 11-12ft from the MLP. I use this location for my third sub placement as it has the best low end response which compliments my nearfield subs. The sweeps are taken post Audyssey correction.

This first set of measurements is with the LFA set mid(12:00), then adjusted max. This applies a ton of boost down low. I run out of headroom around MV -5 with the sub trim boosted 5db. I can also hear some brief vent noise.


The second set of measurements is with LFA set mid and left mid post calibration. I was able to run the volume up to +2 and THD eclipsed 11%. Some of that could be being picked up by rattles and room vibrations. At the MV-0 sweep THD was 8%. Not bad at all really and this sub was able to achieve almost 106db @ 10hz. Also there was very little vent noise on the highest sweep.
That is some performance for a sub that size! Hitting those numbers from 11-12ft away is fantastic...very impressed

Subwoofers: Dual Rythmik FV18s Rev2 with Paper cone, BOSS Platform mini riser, 2 BK LFE
Speakers: PSA MTM-210 L/C/R - Klipsch 250S Surrounds, PSA MT 110sr Rear Surrounds, 4 x SVS Prime Elevation for Atmos
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post #13930 of 13951 Old 01-13-2020, 10:57 AM
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Originally Posted by basshead81 View Post
I have today off so I was able to do some more testing. I have completed a set of compression tests of the JTR 1200xs solo. The JTR resides about 11-12ft from the MLP.
Thanks for posting. Quite impressive . Look to be +-3db at 12Hz, so it is not a 10hz tuned sub? more like 12ish? Can you post the distortion graphs for the highest sweep right before compression? While most MFR is coming out with big and bigger sub(s), what Jeff can achieve with this tiny sub is to be applauded. Jeff should continue offering this sub (say at $1699 price?) as not every one can fit a fridge sized sub.
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post #13931 of 13951 Old 01-13-2020, 11:17 AM
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Originally Posted by tvuong View Post
Thanks for posting. Quite impressive . Look to be +-3db at 12Hz, so it is not a 10hz tuned sub? more like 12ish? Can you post the distortion graphs for the highest sweep right before compression? While most MFR is coming out with big and bigger sub(s), what Jeff can achieve with this tiny sub is to be applauded. Jeff should continue offering this sub (say at $1699 price?) as not every one can fit a fridge sized sub.
I believe the port tune is 10-11hz, but he placed a 12hz hpf after swapping the amps to the 1200 watt units.
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post #13932 of 13951 Old 01-13-2020, 11:19 AM
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Originally Posted by tvuong View Post
Thanks for posting. Quite impressive . Look to be +-3db at 12Hz, so it is not a 10hz tuned sub? more like 12ish? Can you post the distortion graphs for the highest sweep right before compression? While most MFR is coming out with big and bigger sub(s), what Jeff can achieve with this tiny sub is to be applauded. Jeff should continue offering this sub (say at $1699 price?) as not every one can fit a fridge sized sub.
I thought it was tuned at 10Hz and Jeff put a 12Hz HPF on it to limit the chance of any port noise
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post #13933 of 13951 Old 01-13-2020, 11:56 AM
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Originally Posted by Jeff Permanian View Post
Most people end up at 1/4 - 1/3 of the LF Adjust with the sealed subs for a flat response in room (ported 0 - 1/4). However, seems that when using auto room correction, people have getting the best results from having the LF adjust all the way down and then turning it up after room correction. Because subwoofers typically have higher max output on the topend vs the lowend, you end up with increased head room with lower LF Adjust.
Quote:
Originally Posted by chucky7 View Post
Adam,

You're welcome!

In your previous setting (with LFA @ 9 during Audy calibration, and LFA @ 9 after), Audy basically neutered a lot of output below 25Hz at the same MV. I believe you probably don't even need to run LFA @ more than half way now to be at where you were before, and your door and ground should shake more with the LFA above half way.

Movies such as Aquaman and Hunter Killer should be scarier now...
Chucky and Jeff,

Thanks for the guidance and advice. Based on your combined opinions I have changed the LFA on both 2400ULF’s to position 3 of 10. Rewatching “Interstellar” UHD now. Last time I watched this Movie @ -20db MV it literally made the house levitate and every glass, plate, silverware, and hanging art work, shake, rattle and roll like an actual Train Locomotive passing at full steam right through the middle of my House. That was with LFA on 9 of 10.

Can I say “Too much Bass is a thing!” Wife ULF Ejection Seat!

Will report back after I have time to experiment on this new setting.

Jeff you should attach “Warning Labels” on your Industrial Ultrasonic Hammers you call Subwoofers!

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post #13934 of 13951 Old 01-13-2020, 12:34 PM
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Quote:
Originally Posted by Jeff Permanian View Post
Most people end up at 1/4 - 1/3 of the LF Adjust with the sealed subs for a flat response in room (ported 0 - 1/4). However, seems that when using auto room correction, people have getting the best results from having the LF adjust all the way down and then turning it up after room correction. Because subwoofers typically have higher max output on the topend vs the lowend, you end up with increased head room with lower LF Adjust.
I used a slightly different process, which was to have the LF Adjust set how I planned to use it prior to calibration. That said, I am using the Multi-Sub Optimizer software to create biquad filters to import into the output channels of a miniDSP. Since I wanted to have the subs set up with the response it was expecting, I figured that included setting the best LF Adjust setting for my room prior to optimization. Again, this is not the case of Audyssey neutering the bass. Just in case I made a bonehead move, let me tell what I did.

I am using three pairs of equidistant subwoofers.

Subwoofer Information
Subwoofer 1: 4000ULF-ST behind the screen wall.
Subwoofer 2: SubMersive HP on the side walls.
Subwoofer 3: SubMersive HP+ Master & Slave on the rear wall.

For Sub 1 and Sub three, they have the LF Adjustment, so I measured with REW for each sub-woofer pair independently, with the LF Adjust dial at each setting. I used the LF Adjust setting that resulted in the best response. In both subwoofer pair cases, there were dips in the response that were smoothed out when the LF Adjust was increased. For the 4000 ULF's, the response was with the LF Adjust at 9/10, and for the SubMersive HP+, the best response was with the LF Adjust at 10/10. I saved the measurement sets for future reference.

The Multi-Sub Optimizer measurements were taken with these settings, and the optimization performed well, smoothing out the combined response for all three sub-woofer pairs in the room. I then ran Audyssey, but using the Denon/Marantz MultEQ app, I turned down the sub-woofer channel correction to 20 Hz, essentially turning it off.

The results sound great, but let me know if this was a good plan, given the tools and process noted above.

Thanks.

Mark
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post #13935 of 13951 Old 01-13-2020, 05:53 PM
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@JimWilson you did a review on home theater shack for the JTR RS1 subwoofers. Unfortunately the picture links are all broken, and I can’t see your graphs for measurements. Could you please post your graphs for this sub?
When HTS changed hosting providers the images and measurements in all my articles were lost unfortunately. Here are the missing graphs:






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I believe he did one for the S1 not the new RS1
Well, not yet. By this Friday that might change. Just sayin'...
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post #13936 of 13951 Old 01-13-2020, 06:05 PM
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When HTS changed hosting providers the images and measurements in all my articles were lost unfortunately. Here are the missing graphs:

















Well, not yet. By this Friday that might change. Just sayin'...


That would be awesome Jim. Love reading your reviews.


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post #13937 of 13951 Old 01-13-2020, 06:29 PM
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That would be awesome Jim. Love reading your reviews.
Thank you, I'm glad you enjoy the articles.

I probably should clarify Friday... Jeff is swapping my S1 for an RS1 so I will have one in house. I'm working on an eval for another subwoofer at the moment but when that's done I'll hook up the RS1 and give it a work out. I won't be publishing a full review but I will post my comments and take some new measurements. Since I tend to be a bit long winded when I write something it will likely be more than a few paragraphs though.
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post #13938 of 13951 Old 01-13-2020, 06:36 PM
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Thank you, I'm glad you enjoy the articles.



I probably should clarify Friday... Jeff is swapping my S1 for an RS1 so I will have one in house. I'm working on an eval for another subwoofer at the moment but when that's done I'll hook up the RS1 and give it a work out. I won't be publishing a full review but I will post my comments and take some new measurements. Since I tend to be a bit long winded when I write something it will likely be more than a few paragraphs though.


Very nice upgrade. Anything you write will be a delight to read Jim. Looking forward to it.
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post #13939 of 13951 Old 01-17-2020, 07:38 AM
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Guys I have a question about the JTR 2400s. The JTR grill does not cover the port on the bottom. In my case I would be laying the sub down on its side, so the port would be on the side like the picture from above. The exposed port doesn’t look great when the sub is on its side, methinks. But I need a grill for protection.

I am wondering if you all think it might be difficult to create a grill that would also cover the port.

There is not much real estate between the port and the end of the sub, looks like .75 of an inch, so maybe the grill attachment points would have to be right before the port, meaning in between the driver and the port.

I have emailed Jeff about this and am waiting for a response but I was just wondering if anyone else has tried this. If anyone has any pictures of the 2400 with the grill on I would be grateful. Thanks
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post #13940 of 13951 Old 01-17-2020, 08:02 AM
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Guys I have a question about the JTR 2400s. The JTR grill does not cover the port on the bottom. In my case I would be laying the sub down on its side, so the port would be on the side like the picture from above. The exposed port doesn’t look great when the sub is on its side, methinks. But I need a grill for protection.



I am wondering if you all think it might be difficult to create a grill that would also cover the port.



There is not much real estate between the port and the end of the sub, looks like .75 of an inch, so maybe the grill attachment points would have to be right before the port, meaning in between the driver and the port.



I have emailed Jeff about this and am waiting for a response but I was just wondering if anyone else has tried this. If anyone has any pictures of the 2400 with the grill on I would be grateful. Thanks


Most JTR owners run their subs nude to marvel at that beast of a driver.


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post #13941 of 13951 Old 01-17-2020, 08:09 AM
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Most JTR owners run their subs nude to marvel at that beast of a driver.


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Exactly...my grill is still in the plastic wrap. lol
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post #13942 of 13951 Old 01-17-2020, 08:14 AM
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Guys I have a question about the JTR 2400s. The JTR grill does not cover the port on the bottom. In my case I would be laying the sub down on its side, so the port would be on the side like the picture from above. The exposed port doesn’t look great when the sub is on its side, methinks. But I need a grill for protection.



I am wondering if you all think it might be difficult to create a grill that would also cover the port.



There is not much real estate between the port and the end of the sub, looks like .75 of an inch, so maybe the grill attachment points would have to be right before the port, meaning in between the driver and the port.



I have emailed Jeff about this and am waiting for a response but I was just wondering if anyone else has tried this. If anyone has any pictures of the 2400 with the grill on I would be grateful. Thanks


Just to add to my previous post, most brands don’t have their grills covering the ports. One exception is Rythmik who does. To be honest the excursion on the JTR driver is so awesome you would want to see it and show off.


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post #13943 of 13951 Old 01-17-2020, 09:30 AM
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Originally Posted by 3fingerbrown View Post
Guys I have a question about the JTR 2400s. The JTR grill does not cover the port on the bottom. In my case I would be laying the sub down on its side, so the port would be on the side like the picture from above. The exposed port doesn’t look great when the sub is on its side, methinks. But I need a grill for protection.

I am wondering if you all think it might be difficult to create a grill that would also cover the port.

There is not much real estate between the port and the end of the sub, looks like .75 of an inch, so maybe the grill attachment points would have to be right before the port, meaning in between the driver and the port.

I have emailed Jeff about this and am waiting for a response but I was just wondering if anyone else has tried this. If anyone has any pictures of the 2400 with the grill on I would be grateful. Thanks








AFAIK, there are more subs with grills NOT COVERING the port.

The purpose of the grill is to protect the drivers. The port does not need protection.

If you're gonna have the sub on its side near field, chances are you will have the sub facing the seating area to maximize TR and port wind. In this case, you shouldn't block the port and won't see the port anyways.

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post #13944 of 13951 Old 01-17-2020, 11:54 AM
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Originally Posted by 3fingerbrown View Post


Guys I have a question about the JTR 2400s. The JTR grill does not cover the port on the bottom. In my case I would be laying the sub down on its side, so the port would be on the side like the picture from above. The exposed port doesn’t look great when the sub is on its side, methinks. But I need a grill for protection.

I am wondering if you all think it might be difficult to create a grill that would also cover the port.

There is not much real estate between the port and the end of the sub, looks like .75 of an inch, so maybe the grill attachment points would have to be right before the port, meaning in between the driver and the port.

I have emailed Jeff about this and am waiting for a response but I was just wondering if anyone else has tried this. If anyone has any pictures of the 2400 with the grill on I would be grateful. Thanks

Hi,

I agree with others who have noted that most ported subwoofers don't have a grille covering the port. Leaving aesthetics aside, or the desire to see the driver moving though, I think that grilles which cover ports can be a little more challenging to implement. For instance, most designers recommend leaving about a port diameter (for a round port) between a port and a fairly dense or solid surface.

SVS subs, which do have grilles covering the ports on the higher-end subs, leave at least an inch or two of clearance between the ports and the metal grille. That may serve multiple purposes, but I think it is at least partly to allow the ports to breathe.

A soft fabric would be sucked-in toward the port on the intake, and billowed out from the port on the exhaust. I'm not saying that Jeff can't make a grille which will cover your ports, but it might have to stand-out a little more from the surface of the cabinet, in order to allow for proper air movement through the port. This is all pretty speculative on my part, so I won't be offended if Jeff says "Nonsense, I can certainly cover the port with a flush-mounted cloth grille!"

But, if he doesn't say that, I might not try to jump through too many hoops to cover the port. If you just leave it as is, with the standard grille, it's not something you are really likely to notice very much, after you have had the sub for a while.

Regards,
Mike

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post #13945 of 13951 Old 01-17-2020, 12:04 PM
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I totally agree there is no purpose to covering the ports other than the aesthetic requirements of my wife. I am trying to disguise these subs as end tables so every little bit helps. But the vents on the 2400 are very small, so it might be fine as it is. If anyone has any pictures of the 2400 with the grill on I would be grateful.

One more question, do the 2400 subs need their own sepert3e electrical circuits with each having a 2400 watt amp? I am sure that is ideal but unfortunately I have my room wired so that they both go into the same circuit, and I think it is a 20 amp circuit.
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post #13946 of 13951 Old 01-17-2020, 12:12 PM
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Quote:
Originally Posted by 3fingerbrown View Post
Guys I have a question about the JTR 2400s. The JTR grill does not cover the port on the bottom. In my case I would be laying the sub down on its side, so the port would be on the side like the picture from above. The exposed port doesn’t look great when the sub is on its side, methinks. But I need a grill for protection.

I am wondering if you all think it might be difficult to create a grill that would also cover the port.

There is not much real estate between the port and the end of the sub, looks like .75 of an inch, so maybe the grill attachment points would have to be right before the port, meaning in between the driver and the port.

I have emailed Jeff about this and am waiting for a response but I was just wondering if anyone else has tried this. If anyone has any pictures of the 2400 with the grill on I would be grateful. Thanks
I have two Captivator 118HT. They are black and sit in corners. I have a dark, dedicated HT. Surprisingly, I nor anybody else notices them. If I took the grill off or added one over the ports, nobody would notice. If yours is stained hardwood in a living room, YMMV. If your situation is like mine, pay it no attention. Even if it's not, install without port covers and see if the subs disappear after a while.
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post #13947 of 13951 Old 01-18-2020, 02:28 AM
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To be honest - I think the fact that JTR ported subs also can double as industrial fans would make me worry that grills would be blown straight off the sub if they covered the vent!!

I've heard of people blowing the grills off their PB13Ultras, so I'd imagine the JTR's grill would get launched clean across the room when push comes to shove lol




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post #13948 of 13951 Old 01-18-2020, 03:57 AM
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One more question, do the 2400 subs need their own sepert3e electrical circuits with each having a 2400 watt amp? I am sure that is ideal but unfortunately I have my room wired so that they both go into the same circuit, and I think it is a 20 amp circuit.
I don't think you need separate circuits with each Cap 2400. It falls under the 'preferred but not required' category.

I too, would like to have separate circuits for my HT gear. As it stands, I have the Cap 4000ULF, AVR, video source, and TV all on one circuit. My normal MV is -8dB with the sub 9~15dB hot. I never had a problem before. Therefore, I think you will be fine.
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post #13949 of 13951 Old 01-18-2020, 08:26 AM
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If anyone has any pictures of the 2400 with the grill on I would be grateful.
For your viewing pleasure!




I meant to post these yesterday morning when you requested them. I was at work and thought, no problem, I have plenty of pictures. Lo and behold, I did have plenty of pictures but I had NO pictures with the grill on. Let me repeat that, I had NO pictures with the grill on, LOL. I literally unpacked the subs and really never put the grills on for any length of time. Like most people have been saying, I go commando with my subs. I let the beasts breath, or in Adams case, the dragons. But you gotta do what you gotta do when the wifey is concerned.

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post #13950 of 13951 Old 01-18-2020, 08:38 AM
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To be honest - I think the fact that JTR ported subs also can double as industrial fans would make me worry that grills would be blown straight off the sub if they covered the vent!!

I've heard of people blowing the grills off their PB13Ultras, so I'd imagine the JTR's grill would get launched clean across the room when push comes to shove lol
That is one hell of a good point! In my case, at night or dark movie room conditions. You can't see the sub ports. In brightly light day time full sun, you can see them, but only if your looking hard.

Your point about Sub wind is a valid concern. I can see the covers being dislodged constantly unless secured on with some type of hardware. And then you are introducing an airflow restriction type of device that may now impact the overall extension performance of the Sub. Lots of complications for a very minor visual tweak.

Just lay a throw pillow or some other decoration in front of the ports while not in use. Just remove said decoration before firing up the Dragons!

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