Official JTR speaker thread - Page 640 - AVS Forum | Home Theater Discussions And Reviews
Baselworld is only a few weeks away. Getting the latest news is easy, Click Here for info on how to join the Watchuseek.com newsletter list. Follow our team for updates featuring event coverage, new product unveilings, watch industry news & more!


Forum Jump: 
Reply
 
Thread Tools
post #19171 of 31063 Old 05-01-2014, 07:16 PM
AVS Special Member
 
jlpowell84's Avatar
 
Join Date: Dec 2012
Location: Eugene, OR
Posts: 5,407
Mentioned: 54 Post(s)
Tagged: 0 Thread(s)
Quoted: 1021 Post(s)
Liked: 394
Quote:
Originally Posted by RMK! View Post

Sounds fishy to me ...A sealed alignment like this in the smaller cabinet with high excursion woofers will create a destructive back wave that will cause unwanted modulation in the CD. This will lead to HF breakup of epic proportions with inverse polars and sound fragmentation.

You simply can't go around violating the laws of Physics without consequences ...

Wow that was like Will Farrell at his debate...

https://www.youtube.com/watch?v=e-NQSAL-c0c

For sale: 2x Seaton Submersive 2400 HP Models. Definitive Technology PM600 HTIB. PM for any interests :)
DIY Sound Group Volt 10 surround speaker build
http://www.avsforum.com/t/1531107/di...axial-speakers
jlpowell84 is online now  
Sponsored Links
Advertisement
 
post #19172 of 31063 Old 05-01-2014, 07:17 PM
AVS Special Member
 
jlpowell84's Avatar
 
Join Date: Dec 2012
Location: Eugene, OR
Posts: 5,407
Mentioned: 54 Post(s)
Tagged: 0 Thread(s)
Quoted: 1021 Post(s)
Liked: 394
Quote:
Originally Posted by N8DOGG View Post

If Jeff sealed the CD area, it could work well.

Exactly, just like my old school updated Triple 8's. They had the sealed middle cab...

For sale: 2x Seaton Submersive 2400 HP Models. Definitive Technology PM600 HTIB. PM for any interests :)
DIY Sound Group Volt 10 surround speaker build
http://www.avsforum.com/t/1531107/di...axial-speakers
jlpowell84 is online now  
post #19173 of 31063 Old 05-01-2014, 07:29 PM
AVS Special Member
 
Nyal Mellor's Avatar
 
Join Date: Aug 2010
Location: SF Bay Area, California, USA
Posts: 1,274
Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 223 Post(s)
Liked: 145
Quote:
Originally Posted by craig john View Post

No matter what Toole says, there is no circumstance where I, (personally), prefer an added reflection... any added reflection, no matter where it comes from. I would much rather listen to the "direct" sound of my speakers than the reflected sound from my room. In fact, I consider anything added by my room to be "distortion." And in the strictest sense, it is. It's something added that is not in the original signal. Some people "like" the distortion of tube amps. Some like the distortion of lots of reflections in their rooms. I, (personally), prefer neither. Some reflections can't be avoided, and I prefer those reflections to be late in arrival and at a lower level.

Craig

So you are listening in a massive anechoic chamber then? If not you still have reflections smile.gif

Want to learn about home theater design and acoustics? Read our blog.

Company: Acoustic Frontiers - design and creation of high performance home theaters for discerning audio/video enthusiasts.
Certifications: HAA Level I & II, THX Video Level I & II, CEDIA EST I & II.
AVS Projects: Plains, Hodor, Beast Unleashed, Savoy, Roll in Reels, Creekside, CIH...
Nyal Mellor is offline  
post #19174 of 31063 Old 05-01-2014, 07:30 PM
AVS Special Member
 
Nyal Mellor's Avatar
 
Join Date: Aug 2010
Location: SF Bay Area, California, USA
Posts: 1,274
Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 223 Post(s)
Liked: 145
Quote:
Originally Posted by RMK! View Post

Sounds fishy to me ...A sealed alignment like this in the smaller cabinet with high excursion woofers will create a destructive back wave that will cause unwanted modulation in the CD. This will lead to HF breakup of epic proportions with inverse polars and sound fragmentation.

You simply can't go around violating the laws of Physics without consequences ...

Aren't the CDs air sealed by nature of their construction from the back wave?

Want to learn about home theater design and acoustics? Read our blog.

Company: Acoustic Frontiers - design and creation of high performance home theaters for discerning audio/video enthusiasts.
Certifications: HAA Level I & II, THX Video Level I & II, CEDIA EST I & II.
AVS Projects: Plains, Hodor, Beast Unleashed, Savoy, Roll in Reels, Creekside, CIH...
Nyal Mellor is offline  
post #19175 of 31063 Old 05-01-2014, 07:31 PM
AVS Special Member
 
Nyal Mellor's Avatar
 
Join Date: Aug 2010
Location: SF Bay Area, California, USA
Posts: 1,274
Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 223 Post(s)
Liked: 145
Quote:
Originally Posted by jlpowell84 View Post

The ceiling is massively important as very early reflections at high db (like 10-15 milliseconds of -5 to-10db reflections can occur). I have read, lots of research, the ceiling has proved to be the single most beneficial treated area in several peoples HT's.

Fully agree, and you know why? It's because most speakers are vertically stacked arrangements of drivers. Look at vertical off axis measurements and you can see some severe nulls and lobing. Speakers can look quite nice in the lateral domain but be horrible vertically.

Want to learn about home theater design and acoustics? Read our blog.

Company: Acoustic Frontiers - design and creation of high performance home theaters for discerning audio/video enthusiasts.
Certifications: HAA Level I & II, THX Video Level I & II, CEDIA EST I & II.
AVS Projects: Plains, Hodor, Beast Unleashed, Savoy, Roll in Reels, Creekside, CIH...
Nyal Mellor is offline  
post #19176 of 31063 Old 05-01-2014, 07:39 PM
AVS Special Member
 
jlpowell84's Avatar
 
Join Date: Dec 2012
Location: Eugene, OR
Posts: 5,407
Mentioned: 54 Post(s)
Tagged: 0 Thread(s)
Quoted: 1021 Post(s)
Liked: 394
Quote:
Originally Posted by Nyal Mellor View Post

Fully agree, and you know why? It's because most speakers are vertically stacked arrangements of drivers. Look at vertical off axis measurements and you can see some severe nulls and lobing. Speakers can look quite nice in the lateral domain but be horrible vertically.

Nice! I love learning more about this stuff. I have JTR Triple 8's so obviously three drivers vertically and slightly just a tad on the higher than center side vertically. When first learning about treatments I always thought the panels needed to be directly above me but boy was I wrong.

For sale: 2x Seaton Submersive 2400 HP Models. Definitive Technology PM600 HTIB. PM for any interests :)
DIY Sound Group Volt 10 surround speaker build
http://www.avsforum.com/t/1531107/di...axial-speakers
jlpowell84 is online now  
post #19177 of 31063 Old 05-01-2014, 10:05 PM
AVS Special Member
 
lbrown105's Avatar
 
Join Date: Nov 2011
Location: Milwaukee, WI
Posts: 1,274
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 394 Post(s)
Liked: 220
Quote:
Originally Posted by Nyal Mellor View Post

Yeah, depends how far the speaker are from the front wall. 4ft gets you a nice cancellation around 80Hz. Closer you push up the reflection into the 100-200Hz range.

Path length difference for direct vs reflected sound, ft = 1130 / (2 * cancellation frequency, Hz). Learn more here: http://redspade-audio.blogspot.com/2011/02/sbir-speaker-boundary-interference.html.

Once you've heard what a baffle wall to the quality of your 50-200Hz bass IMO there is no going back.

Here's the one I did for DBeck's Savoy:

Must be late, but I am not following why 4ft gives 80 hz null by this equation. 1130/2*(80hz)=appox 7.1ft. Please clarify

Pre-Pro: Emotiva XMC-1, DSP: Mini DSP 2x4 balanced
Amplifier: Sunfire TGA7400, Lab Gruppen FP10000Q
Speakers: JTR Noesis 212HT (LCR), JTR Slant 8's (surrounds), 3 Orbit Shifter LFU's
Sources: PS3, HTPC, Dish Network
Projector: Epson 8350
Screen: Seymour XD AT 138" diagonal 16:9
lbrown105 is offline  
post #19178 of 31063 Old 05-02-2014, 03:54 AM
AVS Special Member
 
coolgeek's Avatar
 
Join Date: Sep 2011
Posts: 2,174
Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 489 Post(s)
Liked: 244
Quote:
Originally Posted by jbrown15 View Post

I posted the same thing like three weeks ago saying it would be cool to see an LCR version rather then full towers and guys thought I was crazy for suggesting that.....lol

I just thought it would be cool to see some serious bad A$$ LCR's that didn't need to go down to 20hz like the 215RT's but would still give you that "kick you in the chest" mid bass slam. I sure something like that would have way more mid bass then the 212HT's. And you could still use the Cap S2's for the ultra low stuff.

I have a feeling something like this sealed going down to 50 ro so and coupled with the s2s would be my perfect setup. Should have all the mid bass slam anyone need.
coolgeek is offline  
post #19179 of 31063 Old 05-02-2014, 04:00 AM
AVS Special Member
 
coolgeek's Avatar
 
Join Date: Sep 2011
Posts: 2,174
Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 489 Post(s)
Liked: 244
Quote:
Originally Posted by jlpowell84 View Post

Interesting perspective! I tend to agree more than not. I had a couple leftover panels after my ceiling treatment took another route from a couple 4x24x48 panels that I place in the rear area that has a computer desk and dining table that is never used. I knew they would deal with late reflections. I also built a small panel for a cabinet end as well. I am liking this direct sound and zero echo smile.gif It just feels very pure and untainted is the best way to describe. I volunteer on tuesday nights at a church recovery meeting running media setup. We have a very talented live band with electric guitars, harmonicas, bass guitar, drums of course, electric piano, numerous vocals, and saxophone. The sound in that room is very "live" sounding. I think it sounds good and all compared to some over deadened rooms I have been in but I feel my room, and I suspect yours, have the right amount that is in the middle ground.

Now I am more confused than ever. When I said I was going to put roxul all around my walls and absorbs everything everyone tells me it's a no no. That I would need some diffusers. Else my room would sound dead. So what is true? I need to get right
coolgeek is offline  
post #19180 of 31063 Old 05-02-2014, 05:12 AM
Senior Member
 
staaled's Avatar
 
Join Date: May 2007
Posts: 251
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 24 Post(s)
Liked: 34
Quote:
Originally Posted by coolgeek View Post

Now I am more confused than ever. When I said I was going to put roxul all around my walls and absorbs everything everyone tells me it's a no no. That I would need some diffusers. Else my room would sound dead. So what is true? I need to get right

"Live end -dead end" is a valued approach.
So front wall absorbtion , rear wal diffusion.
The sides you can treat with either , where my choice would be not to absorb refelections from the nearest speaker in stereo but go for the 1st reflection of the opposing one to lessen crosstalk.
staaled is offline  
post #19181 of 31063 Old 05-02-2014, 06:52 AM
AVS Special Member
 
coolgeek's Avatar
 
Join Date: Sep 2011
Posts: 2,174
Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 489 Post(s)
Liked: 244
Quote:
Originally Posted by staaled View Post

"Live end -dead end" is a valued approach.
So front wall absorbtion , rear wal diffusion.
The sides you can treat with either , where my choice would be not to absorb refelections from the nearest speaker in stereo but go for the 1st reflection of the opposing one to lessen crosstalk.

Ok. Dead front then. And half half sides... if I have carpets what to do with ceiling?
coolgeek is offline  
post #19182 of 31063 Old 05-02-2014, 07:40 AM
AVS Special Member
 
jlpowell84's Avatar
 
Join Date: Dec 2012
Location: Eugene, OR
Posts: 5,407
Mentioned: 54 Post(s)
Tagged: 0 Thread(s)
Quoted: 1021 Post(s)
Liked: 394
Quote:
Originally Posted by coolgeek View Post

Now I am more confused than ever. When I said I was going to put roxul all around my walls and absorbs everything everyone tells me it's a no no. That I would need some diffusers. Else my room would sound dead. So what is true? I need to get right

You need to systematically and scientifically place panels for dealing with specular reflections. Just throwing up panels where you "think" is good and never measuring or being sure you need absorption there is a huge mistake. You can do the mirror technique on the walls and ceiling to find your reflection points and treat. That way you "technically" would never have to measure with REW and you can still be "mostly" sure you are dealing with specular reflection points. So bass trapping is easy in the corners the reflection points is other part of treating and needs done scientifically. Too many panels will over deaden your room and become unpleasant. You want to keep some of the liveness which is why some integrate diffusion in. make sense?

For sale: 2x Seaton Submersive 2400 HP Models. Definitive Technology PM600 HTIB. PM for any interests :)
DIY Sound Group Volt 10 surround speaker build
http://www.avsforum.com/t/1531107/di...axial-speakers
jlpowell84 is online now  
post #19183 of 31063 Old 05-02-2014, 08:18 AM
AVS Special Member
 
coolgeek's Avatar
 
Join Date: Sep 2011
Posts: 2,174
Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 489 Post(s)
Liked: 244
Quote:
Originally Posted by jlpowell84 View Post

You need to systematically and scientifically place panels for dealing with specular reflections. Just throwing up panels where you "think" is good and never measuring or being sure you need absorption there is a huge mistake. You can do the mirror technique on the walls and ceiling to find your reflection points and treat. That way you "technically" would never have to measure with REW and you can still be "mostly" sure you are dealing with specular reflection points. So bass trapping is easy in the corners the reflection points is other part of treating and needs done scientifically. Too many panels will over deaden your room and become unpleasant. You want to keep some of the liveness which is why some integrate diffusion in. make sense?

Thanks JL,

So, absorb first reflections, and then diffuse others? Rule of thumb?

Actually I have a similar question as Archaea...

For the frontstage, it's prob the only BIG space behind the screen that I can do bass trap. If i do a typical thx type 'hard' baffle to surround my speakers, then won't i be wasting the 4 feet of space behind that baffle for bass trap? So, it's either do a baffle or a bass trap, right?

So, my plan right now:

1. Dead front-stage (but not sure if i do the baffle or not)
2. first reflection point roxul / pink fluffy
3. Back wall and secondary reflections, diffuse
4. Ceiling, plywood with holes and roxul behind (in case sound do get up above to the kitchen.
5. Riser (thought of using it as bass trap as well and if i do, i am leaving the entire front part opened (12 inches from floor up), and then fill the entire inside with roxul or pink fluffy)
6. floor - carpet... not sure if i should do wood first then carpet (as it's concrete floor) or just carpet alone.
coolgeek is offline  
post #19184 of 31063 Old 05-02-2014, 08:44 AM
Señor Member
 
RMK!'s Avatar
 
Join Date: Oct 2005
Location: 95608
Posts: 6,842
Mentioned: 23 Post(s)
Tagged: 0 Thread(s)
Quoted: 1010 Post(s)
Liked: 828
Since you are building out a new dedicated room, professional assistance would be nice. smile.gif Nyal or the Erskine Group could give you a a turnkey treatments plan.
Quote:
Originally Posted by coolgeek View Post

Thanks JL,

So, absorb first reflections, and then diffuse others? Rule of thumb?

Actually I have a similar question as Archaea...

For the frontstage, it's prob the only BIG space behind the screen that I can do bass trap. If i do a typical thx type 'hard' baffle to surround my speakers, then won't i be wasting the 4 feet of space behind that baffle for bass trap? So, it's either do a baffle or a bass trap, right?

So, my plan right now:

1. Dead front-stage (but not sure if i do the baffle or not)
2. first reflection point roxul / pink fluffy
3. Back wall and secondary reflections, diffuse
4. Ceiling, plywood with holes and roxul behind (in case sound do get up above to the kitchen.
5. Riser (thought of using it as bass trap as well and if i do, i am leaving the entire front part opened (12 inches from floor up), and then fill the entire inside with roxul or pink fluffy)
6. floor - carpet... not sure if i should do wood first then carpet (as it's concrete floor) or just carpet alone.

HToM Extraordinary Evolution

Opinions are not facts.
RMK! is online now  
post #19185 of 31063 Old 05-02-2014, 09:05 AM
AVS Club Gold
 
craig john's Avatar
 
Join Date: Oct 2003
Location: Lancaster, PA
Posts: 10,615
Mentioned: 20 Post(s)
Tagged: 0 Thread(s)
Quoted: 315 Post(s)
Liked: 526
Quote:
Originally Posted by staaled View Post

Like I said , lateral refelections influence these two.
It is a matter of preference then.
Most people find it pleasing and rate it higher.

Professional listeners, ,recording etc., want and like a short decay time to hear better into the recording.
Toole agrees with the "preference" thing:
Quote:
The real solution, for professionals as well as consumers, is loudspeakers that deliver similarly good timbral accuracy in the direct, early reflected and reverberant sound fields. This can be described as a loudspeaker with a flattish, smooth, axial frequency response, with constant directivity (which together result in flattish, smooth, sound power).

Then it becomes an option, whether the room is acoustically damped, or not.

If reflected sounds are absorbed, the listener is placed in a predominantly direct sound field, making the experience more intimate, and the imaging tighter and more precise.

If the reflections are allowed to add their complexity, the overall illusion is altogether more spacious and open, to many listeners, more realistic.

In part, this is a matter of taste.
http://www.harmanaudio.com/all_about_audio/acoustical_design.pdf

Craig

Lombardi said it:
Perfection is not attainable, but if we chase perfection we can catch excellence."

My System

craig john is offline  
post #19186 of 31063 Old 05-02-2014, 09:09 AM
AVS Club Gold
 
craig john's Avatar
 
Join Date: Oct 2003
Location: Lancaster, PA
Posts: 10,615
Mentioned: 20 Post(s)
Tagged: 0 Thread(s)
Quoted: 315 Post(s)
Liked: 526
Quote:
Originally Posted by craig john View Post

No matter what Toole says, there is no circumstance where I, (personally), prefer an added reflection... any added reflection, no matter where it comes from. I would much rather listen to the "direct" sound of my speakers than the reflected sound from my room. In fact, I consider anything added by my room to be "distortion." And in the strictest sense, it is. It's something added that is not in the original signal. Some people "like" the distortion of tube amps. Some like the distortion of lots of reflections in their rooms. I, (personally), prefer neither. Some reflections can't be avoided, and I prefer those reflections to be late in arrival and at a lower level.

Craig

Quote:
Originally Posted by Nyal Mellor View Post

So you are listening in a massive anechoic chamber then? If not you still have reflections smile.gif

Nyal, please see the emphasized text above.

Lombardi said it:
Perfection is not attainable, but if we chase perfection we can catch excellence."

My System

craig john is offline  
post #19187 of 31063 Old 05-02-2014, 09:11 AM
AVS Special Member
 
coolgeek's Avatar
 
Join Date: Sep 2011
Posts: 2,174
Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 489 Post(s)
Liked: 244
Quote:
Originally Posted by RMK! View Post

Since you are building out a new dedicated room, professional assistance would be nice. smile.gif Nyal or the Erskine Group could give you a a turnkey treatments plan.

RMK..

I wish i have the money... I am totally over-budgeted... not just the home theater aspect, but building the entire house... digging deep into my savings...

I did pay GikAcoustics for a plan, it seems simple... but requires the purchase of their products which is not possible to ship to Malaysia... So, i have been reading up a lot on acoustics thread, etc.. and have came up with a simple plan.

Also, I have been to many 'Theater' and 'Audio' rooms designed by 'local experts' and they all don't sound good to me... it seems my natural room with bookshelves sounded better..

I guess, after reading a lot, perhaps, just throwing things around, quasi science, may do the job.. smile.gif

I know people here hate' quasi science' and me too, really, but budget doesn't allow it... proper acoustics from experts will cost me way too much, and perhaps take away the budget i have for the projector...
coolgeek is offline  
post #19188 of 31063 Old 05-02-2014, 09:34 AM
Senior Member
 
staaled's Avatar
 
Join Date: May 2007
Posts: 251
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 24 Post(s)
Liked: 34
Quote:
Originally Posted by craig john View Post

Toole agrees with the "preference" thing:
http://www.harmanaudio.com/all_about_audio/acoustical_design.pdf

Craig
Part no choice part preference I am somewhere in the middle I guess.
I tried two extra GIK 244' s on my front wall recently.
At first I liked the result, but after a while I found it sounded a bit dull , bordering boring.biggrin.gif
So now I am back to my preferred distortion.wink.gif
staaled is offline  
post #19189 of 31063 Old 05-02-2014, 10:02 AM
Señor Member
 
RMK!'s Avatar
 
Join Date: Oct 2005
Location: 95608
Posts: 6,842
Mentioned: 23 Post(s)
Tagged: 0 Thread(s)
Quoted: 1010 Post(s)
Liked: 828
Quote:
Originally Posted by coolgeek View Post

RMK..

I wish i have the money... I am totally over-budgeted... not just the home theater aspect, but building the entire house... digging deep into my savings...

I did pay GikAcoustics for a plan, it seems simple... but requires the purchase of their products which is not possible to ship to Malaysia... So, i have been reading up a lot on acoustics thread, etc.. and have came up with a simple plan.

Also, I have been to many 'Theater' and 'Audio' rooms designed by 'local experts' and they all don't sound good to me... it seems my natural room with bookshelves sounded better..

I guess, after reading a lot, perhaps, just throwing things around, quasi science, may do the job.. smile.gif

I know people here hate' quasi science' and me too, really, but budget doesn't allow it... proper acoustics from experts will cost me way too much, and perhaps take away the budget i have for the projector...

I get it ... did the same thing myself and frankly it is more fun spending your money ...tongue.gif

As the above discussion nicely summarizes, it is all about taste and preference. smile.gif

HToM Extraordinary Evolution

Opinions are not facts.
RMK! is online now  
post #19190 of 31063 Old 05-02-2014, 10:21 AM
AVS Special Member
 
coolgeek's Avatar
 
Join Date: Sep 2011
Posts: 2,174
Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 489 Post(s)
Liked: 244
Quote:
Originally Posted by RMK! View Post

I get it ... did the same thing myself and frankly it is more fun spending your money ...tongue.gif

As the above discussion nicely summarizes, it is all about taste and preference. smile.gif

With the 215s, acoustics may not matter at all.. hahha.. *kidding*biggrin.gif
coolgeek is offline  
post #19191 of 31063 Old 05-02-2014, 10:32 AM
AVS Special Member
 
coolgeek's Avatar
 
Join Date: Sep 2011
Posts: 2,174
Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 489 Post(s)
Liked: 244
$3000 plus sent to Chris at SeymourAV... bank account balance dropping.. mad.gif
coolgeek is offline  
post #19192 of 31063 Old 05-02-2014, 11:26 AM
AVS Special Member
 
Nyal Mellor's Avatar
 
Join Date: Aug 2010
Location: SF Bay Area, California, USA
Posts: 1,274
Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 223 Post(s)
Liked: 145
Quote:
Originally Posted by coolgeek View Post

Thanks JL,

So, absorb first reflections, and then diffuse others? Rule of thumb?

Actually I have a similar question as Archaea...

For the frontstage, it's prob the only BIG space behind the screen that I can do bass trap. If i do a typical thx type 'hard' baffle to surround my speakers, then won't i be wasting the 4 feet of space behind that baffle for bass trap? So, it's either do a baffle or a bass trap, right?

So, my plan right now:

1. Dead front-stage (but not sure if i do the baffle or not)
2. first reflection point roxul / pink fluffy
3. Back wall and secondary reflections, diffuse
4. Ceiling, plywood with holes and roxul behind (in case sound do get up above to the kitchen.
5. Riser (thought of using it as bass trap as well and if i do, i am leaving the entire front part opened (12 inches from floor up), and then fill the entire inside with roxul or pink fluffy)
6. floor - carpet... not sure if i should do wood first then carpet (as it's concrete floor) or just carpet alone.

If you look at the baffle wall design I posted and did for The Savoy you'll see it has slots and is also not continuous, thus the front corners and areas behind the wall can be used for bass absorption.

Want to learn about home theater design and acoustics? Read our blog.

Company: Acoustic Frontiers - design and creation of high performance home theaters for discerning audio/video enthusiasts.
Certifications: HAA Level I & II, THX Video Level I & II, CEDIA EST I & II.
AVS Projects: Plains, Hodor, Beast Unleashed, Savoy, Roll in Reels, Creekside, CIH...
Nyal Mellor is offline  
post #19193 of 31063 Old 05-02-2014, 11:39 AM
AVS Special Member
 
coolgeek's Avatar
 
Join Date: Sep 2011
Posts: 2,174
Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 489 Post(s)
Liked: 244
Quote:
Originally Posted by Nyal Mellor View Post

If you look at the baffle wall design I posted and did for The Savoy you'll see it has slots and is also not continuous, thus the front corners and areas behind the wall can be used for bass absorption.

Oh smart indeed. Problem solved... thanks
coolgeek is offline  
post #19194 of 31063 Old 05-02-2014, 11:56 AM
AVS Special Member
 
lbrown105's Avatar
 
Join Date: Nov 2011
Location: Milwaukee, WI
Posts: 1,274
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 394 Post(s)
Liked: 220
Quote:
Originally Posted by lbrown105 View Post

Must be late, but I am not following why 4ft gives 80 hz null by this equation. 1130/2*(80hz)=appox 7.1ft. Please clarify
any answer on this?

Pre-Pro: Emotiva XMC-1, DSP: Mini DSP 2x4 balanced
Amplifier: Sunfire TGA7400, Lab Gruppen FP10000Q
Speakers: JTR Noesis 212HT (LCR), JTR Slant 8's (surrounds), 3 Orbit Shifter LFU's
Sources: PS3, HTPC, Dish Network
Projector: Epson 8350
Screen: Seymour XD AT 138" diagonal 16:9
lbrown105 is offline  
post #19195 of 31063 Old 05-02-2014, 11:58 AM
AVS Special Member
 
rhed's Avatar
 
Join Date: Nov 2007
Posts: 1,738
Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 445 Post(s)
Liked: 314
Any thoughts on D-sonic mono blocks? I'm thinking 3 of the M3-1500 for the 3 215's.
http://www.d-sonic.net/products/mono/
rhed is online now  
post #19196 of 31063 Old 05-02-2014, 11:59 AM
AVS Club Gold
 
Mike Garrett's Avatar
 
Join Date: Sep 2011
Posts: 11,054
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 2160 Post(s)
Liked: 1155
Send a message via Skype™ to Mike Garrett
Quote:
Originally Posted by Nyal Mellor View Post

Yeah, depends how far the speaker are from the front wall. 4ft gets you a nice cancellation around 80Hz. Closer you push up the reflection into the 100-200Hz range.

Path length difference for direct vs reflected sound, ft = 1130 / (2 * cancellation frequency, Hz). Learn more here: http://redspade-audio.blogspot.com/2011/02/sbir-speaker-boundary-interference.html.

Once you've heard what a baffle wall to the quality of your 50-200Hz bass IMO there is no going back.

Here's the one I did for DBeck's Savoy:


Have a question. Is there a reason for the two outer baffles to line up with the back of the center baffle? Also why not line them up and extend the center baffle until it connects to the right and left baffle? Also are you going to place any absorption material on the baffles?

AV Geek for life. :) Contact for advice and help.
Mike Garrett is offline  
post #19197 of 31063 Old 05-02-2014, 12:10 PM
AVS Special Member
 
coolgeek's Avatar
 
Join Date: Sep 2011
Posts: 2,174
Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 489 Post(s)
Liked: 244
Quote:
Originally Posted by rhed View Post

Any thoughts on D-sonic mono blocks? I'm thinking 3 of the M3-1500 for the 3 215's.
http://www.d-sonic.net/products/mono/

Just a suggestion. A single fp1000 would give you 2000 watts per channel into 4 channels and they play clean.
coolgeek is offline  
post #19198 of 31063 Old 05-02-2014, 12:26 PM
AVS Special Member
 
jlpowell84's Avatar
 
Join Date: Dec 2012
Location: Eugene, OR
Posts: 5,407
Mentioned: 54 Post(s)
Tagged: 0 Thread(s)
Quoted: 1021 Post(s)
Liked: 394
Quote:
Originally Posted by coolgeek View Post

Thanks JL,

So, absorb first reflections, and then diffuse others? Rule of thumb?

Actually I have a similar question as Archaea...

For the frontstage, it's prob the only BIG space behind the screen that I can do bass trap. If i do a typical thx type 'hard' baffle to surround my speakers, then won't i be wasting the 4 feet of space behind that baffle for bass trap? So, it's either do a baffle or a bass trap, right?

So, my plan right now:

1. Dead front-stage (but not sure if i do the baffle or not)
2. first reflection point roxul / pink fluffy
3. Back wall and secondary reflections, diffuse
4. Ceiling, plywood with holes and roxul behind (in case sound do get up above to the kitchen.
5. Riser (thought of using it as bass trap as well and if i do, i am leaving the entire front part opened (12 inches from floor up), and then fill the entire inside with roxul or pink fluffy)
6. floor - carpet... not sure if i should do wood first then carpet (as it's concrete floor) or just carpet alone.

I agree with Rob, at least pay someone to advise you with all you are putting in your system. You can do it yourself through simple techniques, it is possible. But these guys like Rob mentions understand on a very scientific level what is happening with the sound waves we can't see. They also know how to effectively create a positive relationship between absorption and diffusion. But in general you can hit ALL the first reflection points doing the mirror technique. You can then even measure using the ETC in REW by putting a piece of insulation there and see the loudness of your reflections be tamed. REW's ETC will even tell you the distance of the reflection by a right click and drag method. See my ceiling treatment pics I posted. That is a couple feet in front of the MLP and up (obviously). I always thought, before I really learned, that I had to put it right over the MLP. But not so. Bass treatment is easy, corners and pink fluffy or insulation with less gas air flow resistivity is best for bass. Thicker/dense is not good for bass. Really Pink fluffy is the best at anything over 9 inches thick. Its absorption coefficient is supreme at any frequency over other BASIC insulation.

Pink fluffy is about 5,000 on the Air flow resistivity rating. Take that and put it into the AIR FLOW box (5,000) and then add your thickness (have to convert mm to inches). You will then see it will beat stuff like Roxul AFB (Acoustical F.B) that has an air flow rating of 16,600. So for like a 4 inch thick panel Roxul or OC 703 is best since most of us will not have 9 inch thick panels sticking off our walls lol! This calculator will get you familiar on a more scientific level of whats going on. The calculator even has a spot for calculating in an air gap witch is also better but not usually practical cosmetically.

http://www.acousticmodelling.com/porous.php/___possible__unsafe__site__

For sale: 2x Seaton Submersive 2400 HP Models. Definitive Technology PM600 HTIB. PM for any interests :)
DIY Sound Group Volt 10 surround speaker build
http://www.avsforum.com/t/1531107/di...axial-speakers
jlpowell84 is online now  
post #19199 of 31063 Old 05-02-2014, 12:27 PM
AVS Special Member
 
jlpowell84's Avatar
 
Join Date: Dec 2012
Location: Eugene, OR
Posts: 5,407
Mentioned: 54 Post(s)
Tagged: 0 Thread(s)
Quoted: 1021 Post(s)
Liked: 394
does anyone know what the time to ship from the DIY Sound group is? Ordered my kits Tueday...

For sale: 2x Seaton Submersive 2400 HP Models. Definitive Technology PM600 HTIB. PM for any interests :)
DIY Sound Group Volt 10 surround speaker build
http://www.avsforum.com/t/1531107/di...axial-speakers
jlpowell84 is online now  
post #19200 of 31063 Old 05-02-2014, 12:28 PM
AVS Special Member
 
desertdome's Avatar
 
Join Date: Aug 2004
Location: Elkhorn, NE
Posts: 2,430
Mentioned: 67 Post(s)
Tagged: 0 Thread(s)
Quoted: 524 Post(s)
Liked: 530
Quote:
Originally Posted by AV Science Sales 5 View Post

Also why not line them up and extend the center baffle until it connects to the right and left baffle?

From Nyal:
Quote:
Originally Posted by Nyal Mellor 
If you look at the baffle wall design I posted and did for The Savoy you'll see it has slots and is also not continuous, thus the front corners and areas behind the wall can be used for bass absorption.
Quote:
Originally Posted by AV Science Sales 5 View Post

Also are you going to place any absorption material on the baffles?
I believe it is covered with 1" Auralex Platfoam and then 2" Auralex Studiofoam Wedge. Note: Surrounds did not stay on the front stage. biggrin.gif

desertdome is offline  
Reply Speakers

Tags
215RT , 228ht , captivator , Jtr , Jtr Noesis 212ht 212ht Lp
Gear in this thread - 215RT by PriceGrabber.com

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