How to play sub 20 hz on a TC sounds lms-r 15" - AVS Forum
Forum Jump: 
 
Thread Tools
post #1 of 24 Old 08-09-2012, 09:58 AM - Thread Starter
Advanced Member
 
WagBoss's Avatar
 
Join Date: Jan 2012
Location: Ontario, Canada
Posts: 658
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 19
I was trying to play some low frequencies on just a subwoofer driver, no box yet. It is connected from my laptop via 3.5mm to rca into a receiver, then out into a minidsp, then out into a behringer ep4000 which powers my TC sounds lms-r.

If I went 1 hz below 20 it went to zero sub movement. I could get my sub pumping at 20 hz no problem. What could be causing this issue? I have seen videos of people doing 10 hz sin waves and what not.
WagBoss is offline  
Sponsored Links
Advertisement
 
post #2 of 24 Old 08-09-2012, 11:37 AM
AVS Special Member
 
Bill Fitzmaurice's Avatar
 
Join Date: Nov 2009
Location: New Hampshire
Posts: 9,482
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 1286
Quote:
Originally Posted by WagBoss View Post

I was trying to play some low frequencies on just a subwoofer driver, no box yet.
Don't do that, unless your intent on blowing that driver.

Bill Fitzmaurice Loudspeaker Design

The Laws of Physics aren't swayed by opinion.
Bill Fitzmaurice is offline  
post #3 of 24 Old 08-09-2012, 12:43 PM
Advanced Member
 
bwaslo's Avatar
 
Join Date: Jul 2006
Posts: 812
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 16 Post(s)
Liked: 73
error...ignore

DIY Synergy horn spreadsheet http://libinst.com/SynergyCalc/
XSim -free crossover designer and simulator http://libinst.com/Xsim/XSimSetup.exe
bwaslo is offline  
post #4 of 24 Old 08-09-2012, 06:19 PM - Thread Starter
Advanced Member
 
WagBoss's Avatar
 
Join Date: Jan 2012
Location: Ontario, Canada
Posts: 658
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 19
Quote:
Originally Posted by Bill Fitzmaurice View Post

Don't do that, unless your intent on blowing that driver.

Ok, but still, even if it was in a box it has ZERO movement. Like it's off. What would the problem be?
WagBoss is offline  
post #5 of 24 Old 08-09-2012, 06:29 PM
AVS Addicted Member
 
LTD02's Avatar
 
Join Date: Oct 2003
Posts: 16,121
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 198 Post(s)
Liked: 914
perhaps mp3 filtering or something that has chopped off your bass response.

Listen. It's All Good.
LTD02 is offline  
post #6 of 24 Old 08-09-2012, 07:26 PM - Thread Starter
Advanced Member
 
WagBoss's Avatar
 
Join Date: Jan 2012
Location: Ontario, Canada
Posts: 658
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 19
Quote:
Originally Posted by LTD02 View Post

perhaps mp3 filtering or something that has chopped off your bass response.

what eletronic device would have mp3 filtering on?
WagBoss is offline  
post #7 of 24 Old 08-09-2012, 07:26 PM
AVS Special Member
 
beastaudio's Avatar
 
Join Date: Dec 2010
Location: Western NC
Posts: 7,149
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 321 Post(s)
Liked: 618
Quote:
Originally Posted by WagBoss View Post

Ok, but still, even if it was in a box it has ZERO movement. Like it's off. What would the problem be?

Have you tested your response to the amp coming from all the other equipment to see what the rolloff is from your AVR/EQ/whatever else in the chain? Lots of components start rolling off near 20hz. Most sane people do not pursue past that anyways, but we surely do smile.gif

(European models do not accept banana plugs.)

 

"If you done it, it ain't bragging." ~ Walt Whitman

 

AE TD12x SEOS12 Build

Beast's DIY Master Measurement Thread

DIY Emminence Coaxial Surround Thread

beastaudio is offline  
post #8 of 24 Old 08-09-2012, 08:10 PM - Thread Starter
Advanced Member
 
WagBoss's Avatar
 
Join Date: Jan 2012
Location: Ontario, Canada
Posts: 658
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 19
Quote:
Originally Posted by beastaudio View Post

Have you tested your response to the amp coming from all the other equipment to see what the rolloff is from your AVR/EQ/whatever else in the chain? Lots of components start rolling off near 20hz. Most sane people do not pursue past that anyways, but we surely do smile.gif

how would i test that? I am thinking that it is most likely the headphone out on my laptop that can't output below 20 hz. I want that content though, that is the whole point i am building this subwoofer lol. Well sub 20hz from blu-rays not from my laptop, I was just testing the sub with it.

Do AVR's ever have any type of high pass filter on their LFE output? I know my minidsp is set to a 18 hz high pass filter but that still lets content through below, right? Maybe I have it too steep..
WagBoss is offline  
post #9 of 24 Old 08-09-2012, 08:44 PM
AVS Special Member
 
beastaudio's Avatar
 
Join Date: Dec 2010
Location: Western NC
Posts: 7,149
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 321 Post(s)
Liked: 618
Quote:
Originally Posted by WagBoss View Post

how would i test that? I am thinking that it is most likely the headphone out on my laptop that can't output below 20 hz. I want that content though, that is the whole point i am building this subwoofer lol. Well sub 20hz from blu-rays not from my laptop, I was just testing the sub with it.
Do AVR's ever have any type of high pass filter on their LFE output? I know my minidsp is set to a 18 hz high pass filter but that still lets content through below, right? Maybe I have it too steep..

If you dont have any measuring equipment, that is all good smile.gif I assumed you might have omnimic or something like REW. My fault.

headphone out could very possibly be the issue. also, AVR's dont have a cutoff, most consumer equipment starts to roll off around 20hz though, most dont care about FR below that, but WE DO!!!!!

A high pass means the upper freq's are allowed through, so a high pass at 18hz means anything lower than 18hz will be cut off. cut that off and see what you think. with the High Pass Filter you are basically neutering your response below 18hz.

(European models do not accept banana plugs.)

 

"If you done it, it ain't bragging." ~ Walt Whitman

 

AE TD12x SEOS12 Build

Beast's DIY Master Measurement Thread

DIY Emminence Coaxial Surround Thread

beastaudio is offline  
post #10 of 24 Old 08-09-2012, 09:04 PM - Thread Starter
Advanced Member
 
WagBoss's Avatar
 
Join Date: Jan 2012
Location: Ontario, Canada
Posts: 658
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 19
Quote:
Originally Posted by beastaudio View Post

If you dont have any measuring equipment, that is all good smile.gif I assumed you might have omnimic or something like REW. My fault.
headphone out could very possibly be the issue. also, AVR's dont have a cutoff, most consumer equipment starts to roll off around 20hz though, most dont care about FR below that, but WE DO!!!!!
A high pass means the upper freq's are allowed through, so a high pass at 18hz means anything lower than 18hz will be cut off. cut that off and see what you think. with the High Pass Filter you are basically neutering your response below 18hz.

well the high pass is so the driver doesn't over extend at lower frequencies. I probably have it set with a different db/hz drop than I have it modeled with. I have a mic and REW, just don't see the point of measuring, because right when I drop below 20 the sub STOPS. So I know I get 0 db below 20 and its loud at 20.
WagBoss is offline  
post #11 of 24 Old 08-09-2012, 09:08 PM
AVS Special Member
 
beastaudio's Avatar
 
Join Date: Dec 2010
Location: Western NC
Posts: 7,149
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 321 Post(s)
Liked: 618
Quote:
Originally Posted by WagBoss View Post

well the high pass is so the driver doesn't over extend at lower frequencies. I probably have it set with a different db/hz drop than I have it modeled with. I have a mic and REW, just don't see the point of measuring, because right when I drop below 20 the sub STOPS. So I know I get 0 db below 20 and its loud at 20.

headphone out speaks volumes here. I hope... full on zero response is problematic. All I am saying is most electronic equip. starts rolling around that same area. If you are able to measure, it means nothing if the sub is not getting any response below 20hz. There I cannot help you. sorry biggrin.gif try another source?

(European models do not accept banana plugs.)

 

"If you done it, it ain't bragging." ~ Walt Whitman

 

AE TD12x SEOS12 Build

Beast's DIY Master Measurement Thread

DIY Emminence Coaxial Surround Thread

beastaudio is offline  
post #12 of 24 Old 08-10-2012, 01:53 AM
Member
 
paskal9's Avatar
 
Join Date: Jan 2010
Location: tropics @97% humidity
Posts: 138
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 24
Quote:
Originally Posted by WagBoss View Post

how would i test that? I am thinking that it is most likely the headphone out on my laptop that can't output below 20 hz. I want that content though, that is the whole point i am building this subwoofer lol. Well sub 20hz from blu-rays not from my laptop, I was just testing the sub with it.
Do AVR's ever have any type of high pass filter on their LFE output? I know my minidsp is set to a 18 hz high pass filter but that still lets content through below, right? Maybe I have it too steep..
i doubt your laptop headphone out ain't capable of doing below 20Hz. i have a similar test rig as you:

minidsp plugged into a dell latitude e4300 through the 3.5mm headphone out and into a bridged class d amp.

it's fairly easy to test if your laptop are capable of outputting below 20Hz tone: use a software tone generator, ramp the volume level to max on the laptop and look at the minidsp input gain screen. if there's a tone playing from the laptop then minidsp will detect the tone and give a level. make sure to remove any high pass, low pass crossover that you might have.
and do this without turning on the amp powering the sub. you don't wanna give full sine sweep to a driver in free air.

or if you have any external usb powered speakers plug them in and generate a 20hz tone. my laptop speaker could produce a low tone when i generate 20hz tone without anything connected.

paskal9 is offline  
post #13 of 24 Old 08-10-2012, 05:10 AM - Thread Starter
Advanced Member
 
WagBoss's Avatar
 
Join Date: Jan 2012
Location: Ontario, Canada
Posts: 658
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 19
I'm going from laptop > AVR > minidsp (sub only) > ep4000> tc sounds lms-r

I'm thinking it's the settings on the high pass filter. What type of filter and what Q/ freq should I use? I want to make sure my driver doesn't over extend but I still want to be able to play lower frequencies.
WagBoss is offline  
post #14 of 24 Old 08-10-2012, 05:33 AM
AVS Addicted Member
 
LTD02's Avatar
 
Join Date: Oct 2003
Posts: 16,121
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 198 Post(s)
Liked: 914
"I know my minidsp is set to a 18 hz high pass filter but that still lets content through below, right? Maybe I have it too steep..."

you have a high pass filter set and are wondering why you don't have significant spl below that frequency?

that is kind of the whole point of a high pass filter.

Listen. It's All Good.
LTD02 is offline  
post #15 of 24 Old 08-10-2012, 06:27 AM
AVS Special Member
 
beastaudio's Avatar
 
Join Date: Dec 2010
Location: Western NC
Posts: 7,149
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 321 Post(s)
Liked: 618
either take the hpf off, or move it to 10hz or so. Sealed box setup right? you really dont even need one. while doing free-air, be very careful...

(European models do not accept banana plugs.)

 

"If you done it, it ain't bragging." ~ Walt Whitman

 

AE TD12x SEOS12 Build

Beast's DIY Master Measurement Thread

DIY Emminence Coaxial Surround Thread

beastaudio is offline  
post #16 of 24 Old 08-10-2012, 09:20 AM - Thread Starter
Advanced Member
 
WagBoss's Avatar
 
Join Date: Jan 2012
Location: Ontario, Canada
Posts: 658
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 19
Quote:
Originally Posted by LTD02 View Post

"I know my minidsp is set to a 18 hz high pass filter but that still lets content through below, right? Maybe I have it too steep..."
you have a high pass filter set and are wondering why you don't have significant spl below that frequency?
that is kind of the whole point of a high pass filter.

lol, but on my winisd model I should get content down to nearly 5 hz.

I'm not wondering about significant spl, I know it won't be significant.

But I don't even get 0.0001 mm movement. It is like it's off.
WagBoss is offline  
post #17 of 24 Old 08-10-2012, 09:21 AM - Thread Starter
Advanced Member
 
WagBoss's Avatar
 
Join Date: Jan 2012
Location: Ontario, Canada
Posts: 658
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 19
Quote:
Originally Posted by beastaudio View Post

either take the hpf off, or move it to 10hz or so. Sealed box setup right? you really dont even need one. while doing free-air, be very careful...

Nope ported. 6 ft^3 box with a 3x12"x40" port. I don't have the sub in the box yet though. I know you can't hear anything really without the sub in the box, but at lower frequencies, you should still see some movement on the sub shouldn't you?
WagBoss is offline  
post #18 of 24 Old 08-10-2012, 10:10 AM
AVS Special Member
 
beastaudio's Avatar
 
Join Date: Dec 2010
Location: Western NC
Posts: 7,149
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 321 Post(s)
Liked: 618
Quote:
Originally Posted by WagBoss View Post

Nope ported. 6 ft^3 box with a 3x12"x40" port. I don't have the sub in the box yet though. I know you can't hear anything really without the sub in the box, but at lower frequencies, you should still see some movement on the sub shouldn't you?

For sure, at 10hz my RE's are going crazy (in box). I dont know what to tell you other than maybe try other sources, or start taking diffferent things out of the chain and see if it improves.

(European models do not accept banana plugs.)

 

"If you done it, it ain't bragging." ~ Walt Whitman

 

AE TD12x SEOS12 Build

Beast's DIY Master Measurement Thread

DIY Emminence Coaxial Surround Thread

beastaudio is offline  
post #19 of 24 Old 08-10-2012, 01:11 PM - Thread Starter
Advanced Member
 
WagBoss's Avatar
 
Join Date: Jan 2012
Location: Ontario, Canada
Posts: 658
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 19
Quote:
Originally Posted by beastaudio View Post

For sure, at 10hz my RE's are going crazy (in box). I dont know what to tell you other than maybe try other sources, or start taking diffferent things out of the chain and see if it improves.

Gotta be my hpf, im thinking i have a 4th order on instead of a 2nd order. I'll check when I get home from work.
WagBoss is offline  
post #20 of 24 Old 08-11-2012, 01:12 PM
AVS Special Member
 
BassThatHz's Avatar
 
Join Date: Apr 2008
Location: East side of NW Cascades
Posts: 2,748
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 160 Post(s)
Liked: 330
I'm more afraid for the amp than the sub.
The EP4k with its Class A/B output-stage tends to overheat and/or clip very quickly below 20hz.
Most subs can survive 10 second bursts between 5-10hz with a rest period of X, but going lower/beyond that is totally at your risk.

The videos that you've seen from notnyt, popalock and myself are done with FP14K and IT8K class amplifiers, with 18 Ultra's that are rated for handling 2kW RMS thermals.

Even with 48/db per oct at 25hz you'd still be getting some output at 19hz. This is weird.
Sounds like something digital. Try lowering the Hz in 1/10th increments and see more precisely where it is brickwalling.
Not that that helps any.
BassThatHz is offline  
post #21 of 24 Old 08-12-2012, 04:45 PM - Thread Starter
Advanced Member
 
WagBoss's Avatar
 
Join Date: Jan 2012
Location: Ontario, Canada
Posts: 658
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 19
Also I think I figured out why it wasn't playing below 20 hz. I had a 4th order HPF set at 18 hz, and also had the EP4k's 30 hz HPF on by accident. lol so had like -60dB at 15 hz or something like that. Haven't tested it after fixing the two HPF's, but once I finish my box I can. Should be done in a couple days just finished using wood filler, have to veneer and stain now smile.gif
WagBoss is offline  
post #22 of 24 Old 08-13-2012, 01:29 PM
AVS Special Member
 
beastaudio's Avatar
 
Join Date: Dec 2010
Location: Western NC
Posts: 7,149
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 321 Post(s)
Liked: 618
Quote:
Originally Posted by WagBoss View Post

Also I think I figured out why it wasn't playing below 20 hz. I had a 4th order HPF set at 18 hz, and also had the EP4k's 30 hz HPF on by accident. lol so had like -60dB at 15 hz or something like that. Haven't tested it after fixing the two HPF's, but once I finish my box I can. Should be done in a couple days just finished using wood filler, have to veneer and stain now smile.gif


BLEH

Gross, get rid of that stuff on the EP completely and run all your filters through the Mini

(European models do not accept banana plugs.)

 

"If you done it, it ain't bragging." ~ Walt Whitman

 

AE TD12x SEOS12 Build

Beast's DIY Master Measurement Thread

DIY Emminence Coaxial Surround Thread

beastaudio is offline  
post #23 of 24 Old 08-13-2012, 01:45 PM
Bass Enabler
 
Scott Simonian's Avatar
 
Join Date: Oct 2001
Location: Clovis, CA
Posts: 13,436
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 285 Post(s)
Liked: 717
Quote:
Originally Posted by WagBoss View Post

Also I think I figured out why it wasn't playing below 20 hz. I had a 4th order HPF set at 18 hz, and also had the EP4k's 30 hz HPF on by accident. lol so had like -60dB at 15 hz or something like that. Haven't tested it after fixing the two HPF's, but once I finish my box I can. Should be done in a couple days just finished using wood filler, have to veneer and stain now smile.gif

Lol. Yeah, that will do it. wink.gif

My Dual 18" LLT subs 120dB down to 10hz

 

Plan9Reloaded Co-host

Listen to the Plan9Reloaded Gaming and Technology Podcast (may contain NSFW language)

https://soundcloud.com/plan9reloaded/sets/podcast - direct pod link

http://plan9reloaded.com/site/ - main website

Scott Simonian is offline  
post #24 of 24 Old 08-13-2012, 02:52 PM - Thread Starter
Advanced Member
 
WagBoss's Avatar
 
Join Date: Jan 2012
Location: Ontario, Canada
Posts: 658
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 19
Quote:
Originally Posted by beastaudio View Post

BLEH
Gross, get rid of that stuff on the EP completely and run all your filters through the Mini

LOL forsure, I didn't mean to turn it on, those switches are so tiny I flicked too many by accident lol.
WagBoss is offline  
Reply DIY Speakers and Subs

User Tag List

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