Why not Higher Freq extension out of RSS315 HO ??,Help - AVS Forum
Forum Jump: 
Reply
 
Thread Tools
post #1 of 39 Old 03-20-2013, 08:59 PM - Thread Starter
Advanced Member
 
randyc1's Avatar
 
Join Date: Dec 2009
Location: Montreal
Posts: 544
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 17 Post(s)
Liked: 18
For some reason I'm getting Higher Freq Extension out of my single (KEF Cube 2 )Sub, ...than one or even both of my (RSS 315 HO-4) Subs ?

I thought maybe the 2 RSS's were canceling out at higher freq ,so i compared using just (1) against the Kef in the same Left corner as the Kef , but the Kef still extends Further up ??

These Dayton Subs are know to extend fairly high , so it should at least keep up with the Kef in the same position no?????

GRAPHS:
-The 2 Purple are the Kef at 80hz crossover and 200hz crossover
-And the 2 Green is the (1) RSS315 with 80 & 200 crossover

randyc1 is offline  
Sponsored Links
Advertisement
 
post #2 of 39 Old 03-20-2013, 09:05 PM
AVS Special Member
 
bass addict's Avatar
 
Join Date: Dec 2003
Location: A padded room
Posts: 3,774
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 7 Post(s)
Liked: 210
Who cares how they sound; they look sweet. biggrin.gif

Box tuning probably has something to do with it.

Achievement Unlocked

Psychotic Episode Averted

bass addict is offline  
post #3 of 39 Old 03-20-2013, 10:02 PM
AVS Special Member
 
Jay1's Avatar
 
Join Date: Aug 2002
Location: AZ
Posts: 3,980
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Liked: 102
What is the sub amp? You definitely have a lot of room reinforcement below 60hz.
Jay1 is offline  
post #4 of 39 Old 03-20-2013, 10:11 PM - Thread Starter
Advanced Member
 
randyc1's Avatar
 
Join Date: Dec 2009
Location: Montreal
Posts: 544
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 17 Post(s)
Liked: 18
Quote:
Originally Posted by Jay1 View Post

What is the sub amp? You definitely have a lot of room reinforcement below 60hz.

It's a Dayton SA1000 , both Subs together =4ohm load

Not sure it's room reinforcement ,room is 22x23 ?? ,...but RSS definitely go lower,... but not as high as the Single Kef in left corner ??
randyc1 is offline  
post #5 of 39 Old 03-20-2013, 10:56 PM
AVS Special Member
 
Jay1's Avatar
 
Join Date: Aug 2002
Location: AZ
Posts: 3,980
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Liked: 102
Quote:
Originally Posted by randyc1 View Post

It's a Dayton SA1000 , both Subs together =4ohm load

Not sure it's room reinforcement ,room is 22x23 ?? ,...but RSS definitely go lower,... but not as high as the Single Kef in left corner ??

This should be an approximation of what your room is doing to the simulated anechoic (winISD) response of your sub, without accounting for additional room modes (50 hz peak)



Your measured response is still extended, but the sub gets a lot of gain below 100hz just because its in a room near the floor/wall.
Jay1 is offline  
post #6 of 39 Old 03-21-2013, 01:54 AM
AVS Special Member
 
mayhem13's Avatar
 
Join Date: Jan 2008
Location: nj
Posts: 3,946
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked: 12
Impedance difference and its effects on the LP filter.
mayhem13 is offline  
post #7 of 39 Old 03-21-2013, 05:33 AM
AVS Special Member
 
Bill Fitzmaurice's Avatar
 
Join Date: Nov 2009
Location: New Hampshire
Posts: 9,287
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 1197
Turn the subs around, aiming them at the wall. As you have them you're getting Allison Effect cancellation in the midbass. You'll probably get a lot better response at the LP with one in the front of the room and one in the back. As you have them they look nice and symmetrical, but low frequencies and symmetrical placement don't get along very well.

Bill Fitzmaurice Loudspeaker Design

The Laws of Physics aren't swayed by opinion.
Bill Fitzmaurice is online now  
post #8 of 39 Old 03-21-2013, 05:52 AM
eXa
Member
 
eXa's Avatar
 
Join Date: Jun 2006
Location: Norway
Posts: 181
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 19
I see a rising level as you drop in frequency with a peak at 25 and 50hz
eXa is offline  
post #9 of 39 Old 03-21-2013, 06:59 AM - Thread Starter
Advanced Member
 
randyc1's Avatar
 
Join Date: Dec 2009
Location: Montreal
Posts: 544
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 17 Post(s)
Liked: 18
Quote:
Originally Posted by Bill Fitzmaurice View Post

Turn the subs around, aiming them at the wall. As you have them you're getting Allison Effect cancellation in the midbass. You'll probably get a lot better response at the LP with one in the front of the room and one in the back. As you have them they look nice and symmetrical, but low frequencies and symmetrical placement don't get along very well.
Quote:
Originally Posted by Bill Fitzmaurice View Post

Turn the subs around, aiming them at the wall. As you have them you're getting Allison Effect cancellation in the midbass. You'll probably get a lot better response at the LP with one in the front of the room and one in the back. As you have them they look nice and symmetrical, but low frequencies and symmetrical placement don't get along very well.

When i took the graphs , I only (used 1) of the 2 Dayton's,.., the one in the left hand corner to compare to the Kef beside it. ?
randyc1 is offline  
post #10 of 39 Old 03-21-2013, 07:01 AM - Thread Starter
Advanced Member
 
randyc1's Avatar
 
Join Date: Dec 2009
Location: Montreal
Posts: 544
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 17 Post(s)
Liked: 18
Quote:
Originally Posted by mayhem13 View Post

Impedance difference and its effects on the LP filter.

Hey ,did'nt want to bother you with every question I had !

When i took the graphs , I only (used 1) of the 2 Dayton's,.., the one in the left hand corner to compare to the Kef beside it
randyc1 is offline  
post #11 of 39 Old 03-21-2013, 07:58 AM
AVS Addicted Member
 
LTD02's Avatar
 
Join Date: Oct 2003
Posts: 15,935
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 115 Post(s)
Liked: 840
the subwoofer plate amp probably has a low pass filter which is messing up the top end.

sometimes they have one that is adjustable and another one that is hard wired. not sure why and not sure about that specific plate amp.

that is a very interesting optical illusion that you have created there.

Listen. It's All Good.
LTD02 is online now  
post #12 of 39 Old 03-21-2013, 08:03 AM
AVS Addicted Member
 
LTD02's Avatar
 
Join Date: Oct 2003
Posts: 15,935
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 115 Post(s)
Liked: 840
jay, winisd is 2 pi space. anechoic is 4pi.

Listen. It's All Good.
LTD02 is online now  
post #13 of 39 Old 03-21-2013, 08:34 AM
AVS Special Member
 
Bill Fitzmaurice's Avatar
 
Join Date: Nov 2009
Location: New Hampshire
Posts: 9,287
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 1197
Quote:
Originally Posted by LTD02 View Post

jay, winisd is 2 pi space. anechoic is 4pi.
Half-space anechoic is 2 pi. Full space anechoic is 4pi. He should have stated half-space anechoic.

Bill Fitzmaurice Loudspeaker Design

The Laws of Physics aren't swayed by opinion.
Bill Fitzmaurice is online now  
post #14 of 39 Old 03-21-2013, 09:53 AM
AVS Special Member
 
BassThatHz's Avatar
 
Join Date: Apr 2008
Location: East side of NW Cascades
Posts: 2,611
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 112 Post(s)
Liked: 308
Probably the amp is rolling off the highs.
With a nu3000DSP (for example), you could probably set the XO at 200hz/48db.
With the DA1000, it probably doesn't have that ability.

But me personally, I've never liked the resulting sound when my subs were playing notes much higher than 120hz/24db or 140hz/48db (at the highest); too many lower vocals bleed through.

That said, I do have 4 18's @ 354hz/48db, but they are directly radiating into bass trapping material (8 cubic feet of it) and are 180 degree's rotated away from my face.
That's how I get perfectly flat sound above 40hz, without vocal bleed sound.

BassThatHz is online now  
post #15 of 39 Old 03-21-2013, 01:23 PM - Thread Starter
Advanced Member
 
randyc1's Avatar
 
Join Date: Dec 2009
Location: Montreal
Posts: 544
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 17 Post(s)
Liked: 18
Quote:
Originally Posted by LTD02 View Post

the subwoofer plate amp probably has a low pass filter which is messing up the top end.

sometimes they have one that is adjustable and another one that is hard wired. not sure why and not sure about that specific plate amp.

that is a very interesting optical illusion that you have created there.

The Kef has a plate amp ,..the Dayton is powered by the SA1000,...Both are crossed at the AV reciever ,once at 80 hz and once at 200hz .

I'm just wondering why the Kef extends further up in the FR than the RSS315 HO-4 ??

Purple is the KEF and Green is 1 RSS,both measured from same left corner.
randyc1 is offline  
post #16 of 39 Old 03-21-2013, 01:30 PM - Thread Starter
Advanced Member
 
randyc1's Avatar
 
Join Date: Dec 2009
Location: Montreal
Posts: 544
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 17 Post(s)
Liked: 18
Quote:
Originally Posted by mayhem13 View Post

Impedance difference and its effects on the LP filter.


Does this stll apply using just 1 at 8 ohm like I did ?
randyc1 is offline  
post #17 of 39 Old 03-21-2013, 02:47 PM
AVS Addicted Member
 
LTD02's Avatar
 
Join Date: Oct 2003
Posts: 15,935
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 115 Post(s)
Liked: 840
nice catch mayhem. so the 200hz crossover probably isn't really 200hz because the impedance of 8 ohms is higher than the 4 that the amp is likely expecting, as a result the crossover point is much lower than what is thought?

Listen. It's All Good.
LTD02 is online now  
post #18 of 39 Old 03-21-2013, 03:41 PM
AVS Special Member
 
tuxedocivic's Avatar
 
Join Date: Feb 2010
Location: Ladysmith, BC
Posts: 4,365
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 157 Post(s)
Liked: 435
How is impedance involved in this at all? It's an active cross over.

Randy, I honestly don't know what would cause that. The kef driver might have a rising response. Or the box is to small so it has a falling response (as frequency decreases the output descreses). That would be my guess. The kef should be in a bigger box and tuned lower. The best way to find out what is going on is to get some nearfield measurements.
tuxedocivic is online now  
post #19 of 39 Old 03-21-2013, 05:47 PM
AVS Special Member
 
mayhem13's Avatar
 
Join Date: Jan 2008
Location: nj
Posts: 3,946
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked: 12
Quote:
Originally Posted by LTD02 View Post

nice catch mayhem. so the 200hz crossover probably isn't really 200hz because the impedance of 8 ohms is higher than the 4 that the amp is likely expecting, as a result the crossover point is much lower than what is thought?

I thought so too......until Randy stated that the Dayton uses the SA1000 and the Kef was using its plate amp......now the solution is more obvious that the filter slope of the Dayton amp is steeper than the Kef which is probobly second order. I originally thought Randy said both were using the SA, where the driver impedance would effect the overall filter slope.
mayhem13 is offline  
post #20 of 39 Old 03-21-2013, 06:22 PM - Thread Starter
Advanced Member
 
randyc1's Avatar
 
Join Date: Dec 2009
Location: Montreal
Posts: 544
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 17 Post(s)
Liked: 18
Quote:
Originally Posted by mayhem13 View Post

Quote:
Originally Posted by LTD02 View Post

nice catch mayhem. so the 200hz crossover probably isn't really 200hz because the impedance of 8 ohms is higher than the 4 that the amp is likely expecting, as a result the crossover point is much lower than what is thought?

I thought so too......until Randy stated that the Dayton uses the SA1000 and the Kef was using its plate amp......now the solution is more obvious that the filter slope of the Dayton amp is steeper than the Kef which is probobly second order. I originally thought Randy said both were using the SA, where the driver impedance would effect the overall filter slope.


What i probably meant to say was that both (RSS Subs) are using the SA1000 Amp. Kef has it's own plate Amp

When using both the RSS's I get the same falling output over 50hz. ... Thought It could be cancellation , so i tried just 1 and got same FR ,

Using LFE cable on Kef and Dayton RSS. Should 1 RSS in same position as Kef have very similar ..or better Upper FR as the Kef ??
randyc1 is offline  
post #21 of 39 Old 03-21-2013, 08:37 PM
AVS Special Member
 
mayhem13's Avatar
 
Join Date: Jan 2008
Location: nj
Posts: 3,946
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked: 12
You need to send the subs a left or right signal to test the upper range effectively. Set both amps to the same low pass filter setting and re measure.
mayhem13 is offline  
post #22 of 39 Old 03-21-2013, 09:01 PM
AVS Special Member
 
tuxedocivic's Avatar
 
Join Date: Feb 2010
Location: Ladysmith, BC
Posts: 4,365
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 157 Post(s)
Liked: 435
Isn't that what he did. He did a 200hz even. I think it's the low end output of the Dayton is SO much more it looks like it has less HF output.
tuxedocivic is online now  
post #23 of 39 Old 03-21-2013, 09:56 PM
AVS Special Member
 
Jay1's Avatar
 
Join Date: Aug 2002
Location: AZ
Posts: 3,980
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Liked: 102
Quote:
Originally Posted by tuxedocivic View Post

...I think it's the low end output of the Dayton is SO much more it looks like it has less HF output.

This
Jay1 is offline  
post #24 of 39 Old 03-21-2013, 10:33 PM
eXa
Member
 
eXa's Avatar
 
Join Date: Jun 2006
Location: Norway
Posts: 181
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 19
Quote:
Originally Posted by Bill Fitzmaurice View Post

Turn the subs around, aiming them at the wall. As you have them you're getting Allison Effect cancellation in the midbass. You'll probably get a lot better response at the LP with one in the front of the room and one in the back. As you have them they look nice and symmetrical, but low frequencies and symmetrical placement don't get along very well.

If that was to take effect at lets say 65hz ish you would need to have them 1.3m out from the wall.
http://www.mh-audio.nl/CancellationFreq.asp
eXa is offline  
post #25 of 39 Old 03-22-2013, 05:26 AM
AVS Special Member
 
Bill Fitzmaurice's Avatar
 
Join Date: Nov 2009
Location: New Hampshire
Posts: 9,287
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 1197
Quote:
Originally Posted by eXa View Post

If that was to take effect at lets say 65hz ish you would need to have them 1.3m out from the wall.
I said midbass. By the look of it the baffle may be far enough from the wall to cause a midbass dip. There will also be a dips from the sidewall reflections, though not being able to see the sidewalls it's difficult to say at what frequency. And of course there will be dips caused by the ceiling and rear wall reflections, where depending on the listening/measuring position relative to those boundaries.

Bill Fitzmaurice Loudspeaker Design

The Laws of Physics aren't swayed by opinion.
Bill Fitzmaurice is online now  
post #26 of 39 Old 03-22-2013, 06:49 AM
eXa
Member
 
eXa's Avatar
 
Join Date: Jun 2006
Location: Norway
Posts: 181
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 19
Yes, and i looked at the graph and picture posted. I dont know how deep thoose subs are but lets just say 50cm, and standing 10cm from the wall. 60cm.
The dip at 65hz cant be cancellation from the closest wall since it would have to be 1.3m out. There seemes to also be a dip at 90 and 180hz which would mean 95cm and 48cm out from the wall.
60cm out would cause a dip around 140-145hz.
The ceeling and wall behind the listening position is to far away to cause any direct cancellation in the midbass region. And the sidewall as you say cant be seen so who knows.
eXa is offline  
post #27 of 39 Old 03-22-2013, 08:30 AM
AVS Special Member
 
Martycool007's Avatar
 
Join Date: Jun 2011
Posts: 3,393
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 95 Post(s)
Liked: 144
Quote:
Originally Posted by eXa View Post

Yes, and i looked at the graph and picture posted. I dont know how deep thoose subs are but lets just say 50cm, and standing 10cm from the wall. 60cm.
The dip at 65hz cant be cancellation from the closest wall since it would have to be 1.3m out. There seemes to also be a dip at 90 and 180hz which would mean 95cm and 48cm out from the wall.
60cm out would cause a dip around 140-145hz.
The ceeling and wall behind the listening position is to far away to cause any direct cancellation in the midbass region. And the sidewall as you say cant be seen so who knows.


How are you able to tell where the dips are at based on the boundries?
Martycool007 is offline  
post #28 of 39 Old 03-22-2013, 08:59 AM
eXa
Member
 
eXa's Avatar
 
Join Date: Jun 2006
Location: Norway
Posts: 181
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 19
3 posts up...
eXa is offline  
post #29 of 39 Old 03-22-2013, 10:14 AM - Thread Starter
Advanced Member
 
randyc1's Avatar
 
Join Date: Dec 2009
Location: Montreal
Posts: 544
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 17 Post(s)
Liked: 18
Quote:
Originally Posted by Bill Fitzmaurice View Post

Quote:
Originally Posted by eXa View Post

If that was to take effect at lets say 65hz ish you would need to have them 1.3m out from the wall.
I said midbass. By the look of it the baffle may be far enough from the wall to cause a midbass dip. There will also be a dips from the sidewall reflections, though not being able to see the sidewalls it's difficult to say at what frequency. And of course there will be dips caused by the ceiling and rear wall reflections, where depending on the listening/measuring position relative to those boundaries.

Here's a pic for a better idea

Again :one graph is 1 Kef against 1 RSS

Second graph is (black) 2 RSS against 1KEF
I consistintly get Higher FR from the Kef ??
Dayton subs usually extend quit high no???( colors are inverted on second graph sorry)[=""]http://www.avsforum.com/content/type/61/id/172913/width/350/height/700[/IMG]
randyc1 is offline  
post #30 of 39 Old 03-22-2013, 11:18 AM
AVS Special Member
 
tuxedocivic's Avatar
 
Join Date: Feb 2010
Location: Ladysmith, BC
Posts: 4,365
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 157 Post(s)
Liked: 435
But how are you level matching things? The input sensitivity of the SA1000 may be lower compared to the Kef amp. In reality, if both subs were to be getting 2.83V at the woofer terminals, the dayton might have 3db on the Kef even at 100hz (where the difference is largest). That would move the whole line way up showing that the Dayton kills the Kef, except at high frequencies then the battle is a little closer, which is what I'd expect.

I'd suggest doing the same measurements with the same amp. And not because of the low pass, that's all taken care of in your receiver. Keep that at 200hz if you really want to know the high frequency performance of the Daytons.
tuxedocivic is online now  
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