Near field sub size - AVS Forum | Home Theater Discussions And Reviews
Forum Jump: 
 1Likes
  • 1 Post By VegaMan
 
Thread Tools
post #1 of 14 Old 01-27-2017, 04:06 PM - Thread Starter
Senior Member
 
handcuff's Avatar
 
Join Date: Apr 2005
Location: Louisville, KY
Posts: 320
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
Liked: 19
Near field sub size

Hey guys,

I keep reading about the awesome experience of near-field effect subs, and thought of a possibility that may work for my HT build...(possibly not, but I gotta have someone else tell me I'm nuts before I go too far).

I am thinking of building a couple of smaller subs into my riser, right up against my front row chairs. What's the 'smallest' drivers I can use and still have a visceral experience? 12's?

My front row with riser build will look something like this: Bombertodd's new theater and more and if I could hide them in the riser, it would save valuable space. I can't do it if they are 18 inch subs. 12 is going to be a challenge (10 would be best, but I am guessing that's not do'able). The absolute highest I can go with the riser is 14 inches. I can add volume to the space by going deep or wide, but not high. I was also thinking multiple drivers (two to four, depending on price).

Thanks in advance.
-Scott

New build: Cedar Creek Home Theater (working name) Construction Thread
Old Theater from previous home: Starting 'The Underground' Theater - My construction threads - Finishing 'The Underground' Theater
handcuff is online now  
Sponsored Links
Advertisement
 
post #2 of 14 Old 01-27-2017, 07:21 PM
Senior Member
 
bscool's Avatar
 
Join Date: Mar 2013
Location: North Dakota
Posts: 226
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 134 Post(s)
Liked: 54
I have seen it done before, I know for sure there are at least 1-2 people on this site that are doing it. You will have to search for it. Also, you could use 15-18" subs depending on their depth. UM-18" is 9" depth as an example, so if you can go up to 14" you will have plenty of room.

EDIT. I looked the pic you linked to, I thought you wanted the subs firing up into the bottom of your seats so nevermind the 18" . I tried looking for the people on here that have them and search doesn't turn it up but I know for sure there are people on here that have them. They must just not have made a specific thread about it. Google came up with a couple, one was over on Home Theater Shack.


Quote:
Originally Posted by handcuff View Post
Hey guys,

I keep reading about the awesome experience of near-field effect subs, and thought of a possibility that may work for my HT build...(possibly not, but I gotta have someone else tell me I'm nuts before I go too far).

I am thinking of building a couple of smaller subs into my riser, right up against my front row chairs. What's the 'smallest' drivers I can use and still have a visceral experience? 12's?

My front row with riser build will look something like this: Bombertodd's new theater and more and if I could hide them in the riser, it would save valuable space. I can't do it if they are 18 inch subs. 12 is going to be a challenge (10 would be best, but I am guessing that's not do'able). The absolute highest I can go with the riser is 14 inches. I can add volume to the space by going deep or wide, but not high. I was also thinking multiple drivers (two to four, depending on price).

Thanks in advance.
-Scott

Last edited by bscool; 01-27-2017 at 07:42 PM.
bscool is online now  
post #3 of 14 Old 01-27-2017, 07:39 PM
Senior Member
 
Raylon's Avatar
 
Join Date: Dec 2015
Location: Chicagoland
Posts: 310
Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 192 Post(s)
Liked: 147
I can tell you from my set of 4 12" nearfield they still provide plenty of oomf. But then I experienced some 15's and they were a whole nother level. I would go with 15's. It's a good middle ground. I just looked through probably a hundred woofers and for small sealed boxes you can't beat the Alpine SWS-15D2 for $110 a piece for nearfield. They model great and are cheap.

If 14" is the biggest you can go though, that will obviously only fit 12's, which will still give you plenty of kick.
Raylon is online now  
 
post #4 of 14 Old 01-27-2017, 09:30 PM - Thread Starter
Senior Member
 
handcuff's Avatar
 
Join Date: Apr 2005
Location: Louisville, KY
Posts: 320
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
Liked: 19
Thanks for the responses so far, guys. I appreciate it.
As I read them, I got the idea of taking an 18 inch and tilting it down so it bounced off the floor and hit the back of the chairs. Facing downward at an angle, I could fit an 18 in 14 inches of space. Presumably, wouldn't this work since subs are omnidirectional?
handcuff is online now  
post #5 of 14 Old 01-27-2017, 11:44 PM
Senior Member
 
Raylon's Avatar
 
Join Date: Dec 2015
Location: Chicagoland
Posts: 310
Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 192 Post(s)
Liked: 147
Quote:
Originally Posted by handcuff View Post
Thanks for the responses so far, guys. I appreciate it.
As I read them, I got the idea of taking an 18 inch and tilting it down so it bounced off the floor and hit the back of the chairs. Facing downward at an angle, I could fit an 18 in 14 inches of space. Presumably, wouldn't this work since subs are omnidirectional?
Down won't have the same effect as pointing directly at the seat. Nearfield are awesome because you get that direct beating from the sub. A bounce probably diminishes all that effect. I would rather take 12s pointed at me than 18's pointed down. You get more bass but lose the tactile feeling. Any way to point them directly at the chair backs?
Raylon is online now  
post #6 of 14 Old 01-28-2017, 04:56 AM
Senior Member
 
Cichlid109's Avatar
 
Join Date: May 2016
Location: House on East Coast
Posts: 251
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 77 Post(s)
Liked: 38
Maybe this will help look up Infinity 1262's and the JBL CS14 threads. The Infinity's were great but now they are discontinued and the current replacements are the JBL's. I have 4 of the Infinity's ( 12" ) 2 behind the sofa and 2 behind the love seat. Each pair is being powered by a nu3000. Will not imply these are as good as my 4 18's but they do add to whatever you are listening to.

Yamaha RX-A2010 1pr. Volt 6LX's and 1pr PolkAudio RT-35 as surrounds, 1pr. Volt 6LX's as Front Height ( these powered by AVR )
BIC DV84 L and R powered by Samson SX2400 BIC DV84 Center powered by Samson SX2400
1 Dual Opposed cabinet with 2 HST18D1's powered by A14K
2 Sealed Marty Cubes with SI DS4 stacked powered by nu-6000
2 Infinity 1262's powered by EPX2800, 2 Infinty 1262's powered by nu3000
Cichlid109 is online now  
post #7 of 14 Old 01-28-2017, 05:17 AM
Senior Member
 
bscool's Avatar
 
Join Date: Mar 2013
Location: North Dakota
Posts: 226
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 134 Post(s)
Liked: 54
Try it, it might even work better because if it is at an angle towards your floor firing into the floor bouncing up towards the back of the chair at an angle, it kinda makes a horn and could increase the output just like corner loading a sub increases its output. If it is built like I am imagining it will funnel all the output into the back of the chair and I think it could work very well.

So you would have the side of the chairs blocked by the riser like in the photo of the other theater? So the sound waves have nowhere else to go really, correct?

Quote:
Originally Posted by handcuff View Post
Thanks for the responses so far, guys. I appreciate it.
As I read them, I got the idea of taking an 18 inch and tilting it down so it bounced off the floor and hit the back of the chairs. Facing downward at an angle, I could fit an 18 in 14 inches of space. Presumably, wouldn't this work since subs are omnidirectional?
bscool is online now  
post #8 of 14 Old 01-28-2017, 05:41 AM
Senior Member
 
bscool's Avatar
 
Join Date: Mar 2013
Location: North Dakota
Posts: 226
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 134 Post(s)
Liked: 54
Or what about angling them up, the back of the chairs are at angle.

Also what about making a little bit of a ledge so to speak so you could fit a a 15-18 but put it up higher. Hard to describe but it would be lets say 4-6" wide and come up? 4,6 or 8". Would kinda be like a little ledge behind your seats only, that was built up. You either carpet it like the rest of the floor to blend in better or put a stone or some type of top to give it a more decorative look.
Attached Thumbnails
Click image for larger version

Name:	5b9787b3dc95d002e7c6fc76a9d0bca7_Ink_LI.jpg
Views:	52
Size:	36.5 KB
ID:	1925105  
bscool is online now  
post #9 of 14 Old 01-28-2017, 07:03 AM
AVS Forum Special Member
 
tjcinnamon's Avatar
 
Join Date: Jul 2008
Posts: 1,474
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 928 Post(s)
Liked: 228
Can anyone comment on the difference between sealed and ported nearfield?

Marantz 7010 for 7.2.4
2 x Paradigm Prestige 75F's
1 x Paradigm Prestige 45C
8 x Paradigm CI Pro P65-R's
Sub 2 x Rythmik LVX12's
TV: LG 65B6
tjcinnamon is offline  
post #10 of 14 Old 01-28-2017, 09:48 AM
Member
 
Join Date: Nov 2015
Location: Chicagoland
Posts: 37
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 10 Post(s)
Liked: 4
Quote:
Originally Posted by tjcinnamon View Post
Can anyone comment on the difference between sealed and ported nearfield?
this seems to be one of those things that constantly pop up, sealed vs ported. people often describe ported enclosures as boomy, or one note with sealed boxes being tight, punchy etc. in reality (at least my version of it) i think it all boils down to design goals, or what you're looking to achieve. the biggest problems i see with ported boxes tend to be high group delays, and "max flat" type designs that don't account for room gain. in the nearfield, are you looking for ULF (below 20hz) as loud as you can get it, or are you going for impact and feeling? if you are going for ULF and shaking things, sealed box will be the go to as a ported enclosure to do it with authority would likely be quite large, and with the space constraints of the typical nearfield install, impractical. however, if you're going for belly rumbling and impact, i think a well done ported enclosure cant be beat.

a couple of photos and sims to illustrate what i'm attempting to get at here...
driver used for modeling is the Infinity Ref 1262 @ 300watts
1st photo
red = sealed box "high fidelity" @ 1.8ft^3
yellow = ported box "max flat" @ 3.75ft^3 tuned @ 21hz
the ported enclosures stomps all over the sealed box starting at around 50hz all the way down to about 18hz, where the ported enclosure runs out of excursion and the sealed box will start having a slight advantage. at 12hz and below the sealed box starts taking the output advantage and stays within it's limits for the rest of the ULF area.
the ported box is twice as large, but at 20hz is about 9db louder, so the size is worth it considering you would need 2 more drivers and an additional 600 watts to get close with sealed boxes, not to mention 2 more boxes.

but lets look at room gain.
2nd photo
yellow=ported box
red=sealed
the sim uses a 12db/octave rise with the +3db rise starting at 30hz. ported box again takes the cake from 40hz down to about 18hz (excursion again) but of note is the 3 or 4db spike centered at 20hz. that gain coincides with the huge group delay spike around the same frequency which is 40-ish msec. across the room this would be extremely noticeable, especially in quick moving movie scenes or transients in music. would be "one notey" or "boomy". not too much of a concern in the nearfield, and the extra output that low might be a welcome benefit, but as mentioned previously, likely unpleasant anywhere else in the room.

now for shiggles, an alternative box. a 2 ft^3 enclosure tuned @ 22hz
3rd photo
yellow = max flat ported
red=max flat sealed
pink=2ft^3 ported @ 22hz

with the 2ft^3 ported box the 3 or 4db hump is gone, enclosure size halved to only slightly larger than sealed. excursion is lower through the entire range until tuning, where it runs out of gas at the same time. group delay around tuning is mostly the same, shifted a bit lower. you still net a 6db gain over the sealed enclosure @ 20hz which would take a second driver, box and amp to achieve in a box that is only slightly larger.

TLDR
it's all a compromise. know what you are looking to achieve. if it's all about ULF, sealed boxes, shedloads of power and many drivers is the way to go. for impact w/o the ULF go ported, but look into more than just "max flat" alignments to balance the compromises of a nearfield setup. bass shakers may be more budget friendly to achieve ULF effects. hth
Attached Thumbnails
Click image for larger version

Name:	infin01.JPG
Views:	27
Size:	42.8 KB
ID:	1925649   Click image for larger version

Name:	infin02.JPG
Views:	27
Size:	42.1 KB
ID:	1925657   Click image for larger version

Name:	infin03.JPG
Views:	26
Size:	42.4 KB
ID:	1925857  
Cichlid109 likes this.
VegaMan is offline  
post #11 of 14 Old 01-28-2017, 10:21 AM
Senior Member
 
Cichlid109's Avatar
 
Join Date: May 2016
Location: House on East Coast
Posts: 251
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 77 Post(s)
Liked: 38
I agree completely you said it best it boils down to size if you have the room ported is a good option. There are some that do not care whether their sub can go below 18hz. I on the other hand think its pretty neat to get to 10hz, I may be sacrificing output from 18 and above but I also have a smaller space so sealed works great for me.

Yamaha RX-A2010 1pr. Volt 6LX's and 1pr PolkAudio RT-35 as surrounds, 1pr. Volt 6LX's as Front Height ( these powered by AVR )
BIC DV84 L and R powered by Samson SX2400 BIC DV84 Center powered by Samson SX2400
1 Dual Opposed cabinet with 2 HST18D1's powered by A14K
2 Sealed Marty Cubes with SI DS4 stacked powered by nu-6000
2 Infinity 1262's powered by EPX2800, 2 Infinty 1262's powered by nu3000
Cichlid109 is online now  
post #12 of 14 Old 01-28-2017, 11:11 AM
AVS Forum Special Member
 
derrickdj1's Avatar
 
Join Date: Sep 2011
Posts: 3,465
Mentioned: 89 Post(s)
Tagged: 0 Thread(s)
Quoted: 877 Post(s)
Liked: 590
For Nearfield use, a ported sub will give more tactile response. A ported sub will push air from the driver and port with less power. Check out the ULF and Vibsensor threads. You don't need to center the decision of port vs sealed in the nearfield. Ported will win.

If space is a big problem, consider some tactile transducer. These are especially good for HT's in basements. A few good TT's can easily take the place of 4 big subs with 18 in. drivers.

Last edited by derrickdj1; 01-28-2017 at 11:19 AM.
derrickdj1 is online now  
post #13 of 14 Old 01-28-2017, 08:12 PM
AVS Forum Special Member
 
krholmberg's Avatar
 
Join Date: Jun 2005
Posts: 1,180
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 105 Post(s)
Liked: 28
Quote:
Originally Posted by Cichlid109 View Post
Maybe this will help look up Infinity 1262's and the JBL CS14 threads. The Infinity's were great but now they are discontinued and the current replacements are the JBL's. I have 4 of the Infinity's ( 12" ) 2 behind the sofa and 2 behind the love seat. Each pair is being powered by a nu3000. Will not imply these are as good as my 4 18's but they do add to whatever you are listening to.
How do you have them wired? I have four 1262's and four 2cuft sealed flat packs in the garage waiting to be put together and installed. I'm trying to decide what to do about powering them. I also have four 18's but mine are in an IB. I'm considering getting an NU4-6000 but I would have a pair of 1262's driven by one channel and the second pair driven by another channel. They would be wired so each channel sees a 4ohm load. My 18's are 2ohm drivers so the two pairs would be wired in series so each of the other channels would also see a 4ohm load. Each speaker in that arrangement should get about 325 watts RMS I believe.

Sent from my T-Mobile device using Tapatalk

Krister

Last edited by krholmberg; 01-28-2017 at 08:39 PM.
krholmberg is offline  
post #14 of 14 Old 01-29-2017, 04:43 AM
Senior Member
 
Cichlid109's Avatar
 
Join Date: May 2016
Location: House on East Coast
Posts: 251
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 77 Post(s)
Liked: 38
You did not mention which 18's you have but this is what I would ( i like max.potential within reason ) If it were me I would use the 6000 for the subs. You said you have 4 and they are 2 ohm. Wire each pair in series + to - this will get you a 4 ohm load ( I learned this awhile ago series add parallel subtract ) bridge each channel of the amp. You can bridge the 4 channel not the 2 channel. Your 18's will like it. With the 1262's it depends on what you want. I read the thread on the 1262's and even PM eng399 concerning my question before I did it. If you want to power the 1262's with one amp and this depends on you and what you want you can use either a 3000 or a 6000. If you use a 3000 wire each sub in parallel + to +, - to - each sub is now at 2 ohms then you wire 2 subs together in series this will give you 2 pairs of 4 ohm subs. The 3000 will push all 4 quite nicely in this configuration if you want more and they will handle it either get another 3000 or get a second 6000 either way you will be tickled. If you use the 3000 without doing any more wiring except to provide a wire to the second amp with the 3000 you can run one pair to the amp use it in bridged mode and according to what I have read you should get somewhere around 2000w to the subs you still can get the same with a 6000 run each pair to its own channel.
You can still use your nu4 -6000 to run it all but I think a second amp would be a little better. If what I said about wiring is confusing look up 12vdc wiring. i still sometimes refer to it just to make sure I am doing it right.

Yamaha RX-A2010 1pr. Volt 6LX's and 1pr PolkAudio RT-35 as surrounds, 1pr. Volt 6LX's as Front Height ( these powered by AVR )
BIC DV84 L and R powered by Samson SX2400 BIC DV84 Center powered by Samson SX2400
1 Dual Opposed cabinet with 2 HST18D1's powered by A14K
2 Sealed Marty Cubes with SI DS4 stacked powered by nu-6000
2 Infinity 1262's powered by EPX2800, 2 Infinty 1262's powered by nu3000
Cichlid109 is online now  
Sponsored Links
Advertisement
 
Reply DIY Speakers and Subs

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off