Official Rythmik Audio Subwoofer thread - Page 532 - AVS Forum | Home Theater Discussions And Reviews

Forum Jump: 
 2955Likes
Reply
 
Thread Tools
post #15931 of 27131 Old 06-13-2014, 06:26 AM
AVS Forum Special Member
 
JT78681's Avatar
 
Join Date: Apr 2012
Location: Austin, Texas
Posts: 3,152
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 1290 Post(s)
Liked: 813
Quote:
Originally Posted by steveting99 View Post
JT78681,

Be aware that Onkyo has had a history of HDMI issues. There is a thread for the TX-NR1010 at AVS: Onkyo TX-NR1010

While not well documented, the TX-NR1010 seems to have sub EQ HT which is great.

I'm just concerned about the reliability of Onkyo's at the moment. If you end up with a lemon at great discount, it's still a lemon at the end.
Steve,

I have done quite a bit of research and I'm aware of the HDMI issues some Onkyo's can have. However, everything I have read on the TX-NR1010 seems to be positive and I don't recall seeing one instance of an HDMI related issue. I do appreciate the heads up though.

Display - LG 65EF9500
Receiver - Denon 4311CI
Speakers - Klipsch RF-82 II's, RC-62 II, RB-61 II's
Subs - Rythmik FV15HP's
JT78681 is offline  
Sponsored Links
Advertisement
 
post #15932 of 27131 Old 06-13-2014, 06:28 AM
AVS Forum Special Member
 
JT78681's Avatar
 
Join Date: Apr 2012
Location: Austin, Texas
Posts: 3,152
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 1290 Post(s)
Liked: 813
Quote:
Originally Posted by basshead81 View Post
Have you cosidered a F25 since majority of your listening is music? This setup will give you the most headroom above 40hz and still offer good deep bass performance. I believe the FV15hp would have the advantage below 20hz, but still should have good output down low. If you were more into HT I would say FV15HP all day in that size room and still may not be a bad idea just in case you start enjoying more blu ray tracks.
I second this and if he can be patient I think they will be back in stock shortly (knock on wood).

Display - LG 65EF9500
Receiver - Denon 4311CI
Speakers - Klipsch RF-82 II's, RC-62 II, RB-61 II's
Subs - Rythmik FV15HP's
JT78681 is offline  
post #15933 of 27131 Old 06-13-2014, 06:37 AM
Member
 
Ace Deprave's Avatar
 
Join Date: Jul 2006
Location: Louisiana
Posts: 196
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 17 Post(s)
Liked: 29
I posted this in the Salk forum at Audiocircle, but I figured I should get opinions here too:

I've been enjoying my Salk Veracity STs and Supercharged Song Center for almost a year now, and it's time to replace my aging Velodyne CT100 sub. I'll be transforming our formal living/dining area into a sealed media/entertaining room, and would like to get some opinions on which sub will be better for my application. I'm a 50/50 music/home theatre guy, so I want something that will play deep, but also be musically accurate and integrate well. The specs on my Velodyne, for comparison sake, are 28hz - 120hz +/- 3 dB.

So here's my dilemma...should I go for dual 12" Rythmiks or a single 15" with the passive radiators? My room is about 3100 cubic feet and won't be open to any other rooms. The only think I know for sure is that I want Jim's version of the Rythmik veneered to match my Veracity STs.

Here is an approximate layout of what the room will end up looking like:

Ace Deprave is offline  
post #15934 of 27131 Old 06-13-2014, 06:41 AM
Senior Member
 
smitty8451's Avatar
 
Join Date: Mar 2013
Location: Sutherlin, Oregon
Posts: 331
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 61 Post(s)
Liked: 83
Cool

Quote:
Originally Posted by JT78681 View Post
I'm thinking about trying out the Anti-Mode 8033S-II. Seems like it's a solid EQ for one or multiple subs and it will automatically apply boosts at different frequencies if you desire. What do you guys think?
I built two Rythmik subs using the DS1510 woofers and PEQ600XLR3 amps and am utilizing an Antimode 8033 SII and have had great results. I am using a Yamaha CX-A5000 preamp that utilizes YPAO. A friend of mine has the Marantz 8801 and one weekend we did side by side comparisons using passive AB switches and believe it or not my system with the Antimode sounded much better even after he spent over an hour calibrating his system using Audysee. I think any stand alone sub eq will do a better job than than Audsyee, YPAO, MCAC as you have much more control of the settings/filters ect.
basshead81 likes this.

Yamaha CX-A5000, ATI AT 2007 Amp (7X200W), ATI AT 2004 Amp (4X200W)Klipsch La Scala II- Main, RB 61's - Front heights, RC-62 - Center, RS-62's - Surround, RS-52's - Rear Surround, 2 Rythmik DS-1510 DIY Subwoofers each connected with Antimode Dual Core 2, Oppo BDP-95, MMF-7.1, Project Phono Box RS, XBox 360, XBox One, Oppo HA-1, TEAC PD-501HR transport, Atech Fabrication 7000 fanless HTPC and TASCAM DA-3000 SS Recorder, Kramer VS-88A Matrix Switch, MiniDSP 4X10HD, Rogue Audio Pharaoh Int amp
smitty8451 is offline  
post #15935 of 27131 Old 06-13-2014, 06:52 AM
AVS Forum Special Member
 
JT78681's Avatar
 
Join Date: Apr 2012
Location: Austin, Texas
Posts: 3,152
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 1290 Post(s)
Liked: 813
Quote:
Originally Posted by smitty8451 View Post
I built two Rythmik subs using the DS1510 woofers and PEQ600XLR3 amps and am utilizing an Antimode 8033 SII and have had great results. I am using a Yamaha CX-A5000 preamp that utilizes YPAO. A friend of mine has the Marantz 8801 and one weekend we did side by side comparisons using passive AB switches and believe it or not my system with the Antimode sounded much better even after he spent over an hour calibrating his system using Audysee. I think any stand alone sub eq will do a better job than than Audsyee, YPAO, MCAC as you have much more control of the settings/filters ect.
Thanks for sharing your experience. My dilemma right now is do I spend $369 on a stand alone sub eq or $1100 and up on a receiver with XT32 and Sub eq? I'm leaning more towards the Antimode just to try it out and see what kind of results I can get out of it. It's worth a shot for a few hundred bucks.

Display - LG 65EF9500
Receiver - Denon 4311CI
Speakers - Klipsch RF-82 II's, RC-62 II, RB-61 II's
Subs - Rythmik FV15HP's

Last edited by JT78681; 06-13-2014 at 06:59 AM.
JT78681 is offline  
post #15936 of 27131 Old 06-13-2014, 07:06 AM
AVS Forum Special Member
 
JT78681's Avatar
 
Join Date: Apr 2012
Location: Austin, Texas
Posts: 3,152
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 1290 Post(s)
Liked: 813
Quote:
Originally Posted by Ace Deprave View Post
I posted this in the Salk forum at Audiocircle, but I figured I should get opinions here too:

I've been enjoying my Salk Veracity STs and Supercharged Song Center for almost a year now, and it's time to replace my aging Velodyne CT100 sub. I'll be transforming our formal living/dining area into a sealed media/entertaining room, and would like to get some opinions on which sub will be better for my application. I'm a 50/50 music/home theatre guy, so I want something that will play deep, but also be musically accurate and integrate well. The specs on my Velodyne, for comparison sake, are 28hz - 120hz +/- 3 dB.

So here's my dilemma...should I go for dual 12" Rythmiks or a single 15" with the passive radiators? My room is about 3100 cubic feet and won't be open to any other rooms. The only think I know for sure is that I want Jim's version of the Rythmik veneered to match my Veracity STs.

Here is an approximate layout of what the room will end up looking like:


Before picking up my second FV15HP I had one in a room over 5000 cu ft completely exposed to the rest of the house. It performed well, but I wanted a second FV to even out the response in my crappy room. You're room is not nearly as big and is sealed. I would try and swing an FV15HP and be done with it. Buy the kit from Rythmik (driver and amp) and find a cabinet maker to build you something that matches the veneer you are after. Heck reach out to Salk and see if they can build you something.

Display - LG 65EF9500
Receiver - Denon 4311CI
Speakers - Klipsch RF-82 II's, RC-62 II, RB-61 II's
Subs - Rythmik FV15HP's
JT78681 is offline  
post #15937 of 27131 Old 06-13-2014, 08:02 AM
Member
 
Ace Deprave's Avatar
 
Join Date: Jul 2006
Location: Louisiana
Posts: 196
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 17 Post(s)
Liked: 29
Quote:
Originally Posted by JT78681 View Post
Before picking up my second FV15HP I had one in a room over 5000 cu ft completely exposed to the rest of the house. It performed well, but I wanted a second FV to even out the response in my crappy room. You're room is not nearly as big and is sealed. I would try and swing an FV15HP and be done with it. Buy the kit from Rythmik (driver and amp) and find a cabinet maker to build you something that matches the veneer you are after. Heck reach out to Salk and see if they can build you something.
I'm definitely going to have Jim Salk build it (them). He offers 3 versions of the Rythmik sub, a 12" sealed, and 15" sealed, and a 15" with dual passive radiators. Since this is a dual purpose room, I'm trying to find a good compromise between both music and home theatre. My old sub would play down to 28hz, and I was satisfied with it for home theatre...it was music that I never could get right. That's why I'm, at this point, leaning toward dual 12".
Ace Deprave is offline  
post #15938 of 27131 Old 06-13-2014, 08:15 AM
AVS Forum Special Member
 
JT78681's Avatar
 
Join Date: Apr 2012
Location: Austin, Texas
Posts: 3,152
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 1290 Post(s)
Liked: 813
Quote:
Originally Posted by Ace Deprave View Post
I'm definitely going to have Jim Salk build it (them). He offers 3 versions of the Rythmik sub, a 12" sealed, and 15" sealed, and a 15" with dual passive radiators. Since this is a dual purpose room, I'm trying to find a good compromise between both music and home theatre. My old sub would play down to 28hz, and I was satisfied with it for home theatre...it was music that I never could get right. That's why I'm, at this point, leaning toward dual 12".
The FV15HP sounds impressive with music. That's the beauty of it having such a rich amplifier. It's loaded with so many features that you can tailor the sound to suit your needs with the flip of a switch or two. I know he only offers those 3 versions on the website, but I'm sure he could build you a cab for the FV15HP. Good luck in your quest!
Ace Deprave likes this.

Display - LG 65EF9500
Receiver - Denon 4311CI
Speakers - Klipsch RF-82 II's, RC-62 II, RB-61 II's
Subs - Rythmik FV15HP's
JT78681 is offline  
post #15939 of 27131 Old 06-13-2014, 10:07 AM
Senior Member
 
johnnymacIII's Avatar
 
Join Date: Apr 2014
Posts: 261
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 148 Post(s)
Liked: 49
Quote:
Originally Posted by JRMNorth View Post
Thanks!

I appreciate all of your suggestions.

To respond to DonH50s question - the two LV12Rs do not go as deep as the F15 I previously had. I had the F15 set to 14hz - so that is expected. I just miss the deep bass it provided. I expect the FV15HP will come close. I was mostly wondering if one FV15HP would be able to provide fairly even bass in such a large room. Or, if two subs would be needed.

Thanks,

John
Hi John. Here is a good article by Nyal Mellor that might help you with multiple subwoofers and bass response.

http://www.acousticfrontiers.com/home-theater-blog/2013/10/9/multiple-subwoofer-case-study-af-demo-room
johnnymacIII is offline  
post #15940 of 27131 Old 06-13-2014, 10:52 AM
Advanced Member
 
Blacklightning's Avatar
 
Join Date: Jan 2006
Location: Edmonton,AB Canada
Posts: 883
Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 405 Post(s)
Liked: 276
Quote:
Originally Posted by Ace Deprave View Post
I posted this in the Salk forum at Audiocircle, but I figured I should get opinions here too:

I've been enjoying my Salk Veracity STs and Supercharged Song Center for almost a year now, and it's time to replace my aging Velodyne CT100 sub. I'll be transforming our formal living/dining area into a sealed media/entertaining room, and would like to get some opinions on which sub will be better for my application. I'm a 50/50 music/home theatre guy, so I want something that will play deep, but also be musically accurate and integrate well. The specs on my Velodyne, for comparison sake, are 28hz - 120hz +/- 3 dB.

So here's my dilemma...should I go for dual 12" Rythmiks or a single 15" with the passive radiators? My room is about 3100 cubic feet and won't be open to any other rooms. The only think I know for sure is that I want Jim's version of the Rythmik veneered to match my Veracity STs.

Here is an approximate layout of what the room will end up looking like:

If you are going to stick with SALK, the 15" with Passive Rad will be close to the FV15. I would stick to dual as much as possible so my vote would be the dual 12's... if you are not a bass head.
Blacklightning is offline  
post #15941 of 27131 Old 06-13-2014, 10:57 AM
AVS Special Member
 
qguy's Avatar
 
Join Date: Dec 2008
Posts: 1,151
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 121 Post(s)
Liked: 89
WOW Any pics of this wicked setup ?

Quote:
Originally Posted by dragonleepenn View Post

I do this with my 3 F25's and two F15's , I set the levels so they all match before Audyssey ,

PeterV
qguy is offline  
post #15942 of 27131 Old 06-13-2014, 11:04 AM
AVS Special Member
 
tvuong's Avatar
 
Join Date: Dec 2000
Posts: 3,755
Mentioned: 36 Post(s)
Tagged: 0 Thread(s)
Quoted: 1486 Post(s)
Liked: 830
^^ He did post picture but it was hard to see the subs
tvuong is offline  
post #15943 of 27131 Old 06-13-2014, 11:21 AM
AVS Addicted Member
 
sdurani's Avatar
 
Join Date: Oct 2001
Location: Monterey Park, CA
Posts: 24,243
Mentioned: 60 Post(s)
Tagged: 0 Thread(s)
Quoted: 4260 Post(s)
Liked: 2716
Quote:
Originally Posted by Ace Deprave View Post
So here's my dilemma...should I go for dual 12" Rythmiks or a single 15" with the passive radiators?
I would definitely go for the dual 12" subs, placed at 1/4 and 3/4 of room width, which will help smoothen out the bass response across your main seating area. Can't do that with a single sub, no matter how big it is nor how much output it has.

Sanjay
sdurani is offline  
post #15944 of 27131 Old 06-13-2014, 11:23 AM
AVS Special Member
 
qguy's Avatar
 
Join Date: Dec 2008
Posts: 1,151
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 121 Post(s)
Liked: 89
Must be a big @$$ room, he may need bigger subs

Quote:
Originally Posted by tvuong View Post
^^ He did post picture but it was hard to see the subs
qguy is offline  
post #15945 of 27131 Old 06-13-2014, 01:09 PM
AVS Special Member
 
bear123's Avatar
 
Join Date: Dec 2013
Location: PA
Posts: 4,846
Mentioned: 26 Post(s)
Tagged: 0 Thread(s)
Quoted: 1630 Post(s)
Liked: 2369
Quote:
Originally Posted by JT78681 View Post
Thanks for sharing your experience. My dilemma right now is do I spend $369 on a stand alone sub eq or $1100 and up on a receiver with XT32 and Sub eq? I'm leaning more towards the Antimode just to try it out and see what kind of results I can get out of it. It's worth a shot for a few hundred bucks.
Why not get sub eq in the form of the miniDSP for $105? Then it is not attached to your AVR and can be kept in the chain regardless of which AVR you use in the future.
bear123 is offline  
post #15946 of 27131 Old 06-13-2014, 02:01 PM
AVS Special Member
 
DonH50's Avatar
 
Join Date: Feb 2010
Location: Monument CO
Posts: 9,313
Mentioned: 23 Post(s)
Tagged: 0 Thread(s)
Quoted: 1659 Post(s)
Liked: 1205
^^^ +1.

that would be my suggestion, with the caveat that you also need to pick up a measurement mic, download REW, and learn how it all works. If you want a turnkey solution the Antimode is cheapest/easiest for now if it is only $369.

"After silence, that which best expresses the inexpressible, is music" - Aldous Huxley
DonH50 is offline  
post #15947 of 27131 Old 06-13-2014, 02:05 PM
AVS Special Member
 
DonH50's Avatar
 
Join Date: Feb 2010
Location: Monument CO
Posts: 9,313
Mentioned: 23 Post(s)
Tagged: 0 Thread(s)
Quoted: 1659 Post(s)
Liked: 1205
Quote:
Originally Posted by Ace Deprave View Post
So here's my dilemma...should I go for dual 12" Rythmiks or a single 15" with the passive radiators?
That is a fairly complex room layout and still a decent-sized space. For best overall response and decent output I would get two F12's as others have said.

FWIWFM, a couple of years ago when I was shopping and listening I found my F12 matched or overmatched everything up to about $3k+ from Velodyne and several other vendors. Rythmik plays deeper and with less distortion than most commercial products.
Ace Deprave likes this.

"After silence, that which best expresses the inexpressible, is music" - Aldous Huxley
DonH50 is offline  
post #15948 of 27131 Old 06-13-2014, 03:03 PM
Member
 
Ace Deprave's Avatar
 
Join Date: Jul 2006
Location: Louisiana
Posts: 196
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 17 Post(s)
Liked: 29
Quote:
Originally Posted by DonH50 View Post
That is a fairly complex room layout and still a decent-sized space. For best overall response and decent output I would get two F12's as others have said.

FWIWFM, a couple of years ago when I was shopping and listening I found my F12 matched or overmatched everything up to about $3k+ from Velodyne and several other vendors. Rythmik plays deeper and with less distortion than most commercial products.
I'm sure my expectations will be far exceeded going with the 2 F12s. The only sub I've ever had is my old Velodyne, and it only has a 10" driver, a 100 watt amp, and only is rated down to 28Hz. It is vented, and was much better than anything else I auditioned at the time, but that was 15 years ago, and my budget was $500.

Thanks!
Ace Deprave is offline  
post #15949 of 27131 Old 06-13-2014, 03:31 PM
AVS Forum Special Member
 
JT78681's Avatar
 
Join Date: Apr 2012
Location: Austin, Texas
Posts: 3,152
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 1290 Post(s)
Liked: 813
Quote:
Originally Posted by bear123 View Post
Why not get sub eq in the form of the miniDSP for $105? Then it is not attached to your AVR and can be kept in the chain regardless of which AVR you use in the future.
I recently bought and returned a mic from cross spectrum because I got frustrated because I couldn't get REW to detect the mic. I went through all the write ups on here with no luck. I don't mind reading extensive instructions on how to set something up, but after I go through all that and it still doesn't work my patience runs a little thin.
JT78681 is offline  
post #15950 of 27131 Old 06-13-2014, 04:34 PM
AVS Special Member
 
DonH50's Avatar
 
Join Date: Feb 2010
Location: Monument CO
Posts: 9,313
Mentioned: 23 Post(s)
Tagged: 0 Thread(s)
Quoted: 1659 Post(s)
Liked: 1205
Sounds like a PITA. Sounds like a problem with the PC drivers but I do not use REW.

"After silence, that which best expresses the inexpressible, is music" - Aldous Huxley
DonH50 is offline  
post #15951 of 27131 Old 06-13-2014, 08:23 PM
AVS Special Member
 
qguy's Avatar
 
Join Date: Dec 2008
Posts: 1,151
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 121 Post(s)
Liked: 89
I had a 12 inch MK before I had my F15, I was blown away, the Rythmik dances circles around the M&K. I am pretty sure two F12 would blow you away.

Quote:
Originally Posted by Ace Deprave View Post
I'm sure my expectations will be far exceeded going with the 2 F12s. The only sub I've ever had is my old Velodyne, and it only has a 10" driver, a 100 watt amp, and only is rated down to 28Hz. It is vented, and was much better than anything else I auditioned at the time, but that was 15 years ago, and my budget was $500.

Thanks!

Last edited by qguy; 06-13-2014 at 08:45 PM.
qguy is offline  
post #15952 of 27131 Old 06-14-2014, 12:02 AM
AVS Addicted Member
 
basshead81's Avatar
 
Join Date: Mar 2013
Location: Fort Wayne, IN
Posts: 10,124
Mentioned: 55 Post(s)
Tagged: 0 Thread(s)
Quoted: 165 Post(s)
Liked: 4726
Quote:
Originally Posted by smitty8451 View Post
I built two Rythmik subs using the DS1510 woofers and PEQ600XLR3 amps and am utilizing an Antimode 8033 SII and have had great results. I am using a Yamaha CX-A5000 preamp that utilizes YPAO. A friend of mine has the Marantz 8801 and one weekend we did side by side comparisons using passive AB switches and believe it or not my system with the Antimode sounded much better even after he spent over an hour calibrating his system using Audysee. I think any stand alone sub eq will do a better job than than Audsyee, YPAO, MCAC as you have much more control of the settings/filters ect.
Good info!! I too am a believer that a stand alone sub eq setup works much better then any room correction software. Most of the big DIY guys seem to use this approach as well which speaks volumes imo.
basshead81 is offline  
post #15953 of 27131 Old 06-14-2014, 07:37 AM
AVS Forum Special Member
 
rcohen's Avatar
 
Join Date: Feb 2005
Posts: 2,745
Mentioned: 22 Post(s)
Tagged: 0 Thread(s)
Quoted: 1114 Post(s)
Liked: 467
Quote:
Originally Posted by basshead81 View Post
Good info!! I too am a believer that a stand alone sub eq setup works much better then any room correction software. Most of the big DIY guys seem to use this approach as well which speaks volumes imo.
I've gotten good results with XT32 and great results with Dirac Live.
rcohen is offline  
post #15954 of 27131 Old 06-14-2014, 11:38 AM
Advanced Member
 
rak306's Avatar
 
Join Date: Oct 2004
Location: Syracuse NY
Posts: 705
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 372 Post(s)
Liked: 132
Quote:
Originally Posted by Rythmik View Post

.... The difference of these mass difference is very subtle and yet look at all the speaeker measurement with noisy background and poor resolution. That is why we keep going back to the same conclusion -- there is no difference.

Brian,

I am not following what you are saying here. Is it that people don't make good measurements, and wrongly conclude there is no difference in speakers with different mass?

As I see it, the math models of speakers (TS parameters) assume away the non-linearities. As a result, all speakers have the same damped harmonic solution - with the only difference being the Qs (electrical and mechanical), resonant frequency, size, and power handling. And one can equalize them all to be the same. So one might conclude that all similar speakers can be made to sound the same (which is non-sense).

Left out of many speaker specifications are distortion measurements.

IMO all speakers specification should include distortion vs frequency curves with inputs at 0 dB (re rated output), -6 dB, -10 dB, for various input frequencies (e.g. 1/2fo, fo, 2fo).

This would be very telling. Transistors, A/D converters, power amplifiers, all include distortion measurements - why don't speakers? Is it because they are not very good (like 3%-10%)?

Last edited by rak306; 06-14-2014 at 11:39 AM. Reason: clarify
rak306 is offline  
post #15955 of 27131 Old 06-14-2014, 02:29 PM
AVS Forum Special Member
 
rcohen's Avatar
 
Join Date: Feb 2005
Posts: 2,745
Mentioned: 22 Post(s)
Tagged: 0 Thread(s)
Quoted: 1114 Post(s)
Liked: 467
Quote:
Originally Posted by rak306 View Post
Quote:
Originally Posted by Rythmik View Post

.... The difference of these mass difference is very subtle and yet look at all the speaeker measurement with noisy background and poor resolution. That is why we keep going back to the same conclusion -- there is no difference.

Brian,

I am not following what you are saying here. Is it that people don't make good measurements, and wrongly conclude there is no difference in speakers with different mass?

As I see it, the math models of speakers (TS parameters) assume away the non-linearities. As a result, all speakers have the same damped harmonic solution - with the only difference being the Qs (electrical and mechanical), resonant frequency, size, and power handling. And one can equalize them all to be the same. So one might conclude that all similar speakers can be made to sound the same (which is non-sense).

Left out of many speaker specifications are distortion measurements.

IMO all speakers specification should include distortion vs frequency curves with inputs at 0 dB (re rated output), -6 dB, -10 dB, for various input frequencies (e.g. 1/2fo, fo, 2fo).

This would be very telling. Transistors, A/D converters, power amplifiers, all include distortion measurements - why don't speakers? Is it because they are not very good (like 3%-10%)?
I would be really interested to see an article or discussion on the differences (pros, cons) between using feedback (amp and/or servo) versus using signal processing to correct for speaker distortion.
rcohen is offline  
post #15956 of 27131 Old 06-14-2014, 02:35 PM
AVS Special Member
 
DonH50's Avatar
 
Join Date: Feb 2010
Location: Monument CO
Posts: 9,313
Mentioned: 23 Post(s)
Tagged: 0 Thread(s)
Quoted: 1659 Post(s)
Liked: 1205
My off-the-cuff comments not to be confused with Brian's thoughts: In general the earlier in the chain you correct the errors the easier they are to fix. DSP correction requires a very accurate speaker/driver model that will likely get blown out by interaction with the room anyway, or an acoustic sense and feedback scheme that is difficult to implement cleanly and make stable. I've used analog and digital signal processing to correct errors from various components in an RF chain, no reason to think it would be much different for audio. In some ways much harder if you try acoustic sensors, the loop delay is a killer.

Many years ago I built a servo sub using a dual voice-coil woofer and compared it to non-servo and the best subs of the time (mid-80's, Velodyne, many passive designs up to and including a pair of Hartley's in an HQD system). The results sold me on servo and I've been there ever since.

IME/IMO - Don

"After silence, that which best expresses the inexpressible, is music" - Aldous Huxley
DonH50 is offline  
post #15957 of 27131 Old 06-14-2014, 04:45 PM
Advanced Member
 
rak306's Avatar
 
Join Date: Oct 2004
Location: Syracuse NY
Posts: 705
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 372 Post(s)
Liked: 132
Quote:
Originally Posted by DonH50 View Post
My off-the-cuff comments not to be confused with Brian's thoughts: In general the earlier in the chain you correct the errors the easier they are to fix. DSP correction requires a very accurate speaker/driver model that will likely get blown out by interaction with the room anyway, or an acoustic sense and feedback scheme that is difficult to implement cleanly and make stable. I've used analog and digital signal processing to correct errors from various components in an RF chain, no reason to think it would be much different for audio. In some ways much harder if you try acoustic sensors, the loop delay is a killer.
...

IME/IMO - Don
Yes loop delay is a bad thing, but only if you are trying to correct errors at a higher closed loop bandwidth than the loop can support (like you trying to control your room temp. by constantly tweaking the thermostat and not waiting long enough to know what the changes in temp setting did to the room temp - you end up with an oscillation).

I don't think there is very much feedback signal delay in Brian's servo loop. The feedback signal is from the sensor coil (in the speaker coil assembly) driving a cable a few inches going to an OP amp.

To me, the key to a servo solution working is an accurate feedback sensor. If the sensor is not accurate - the servo will not be accurate.

A source of non-linearity in a speaker is a variable BL depending on coil position in the gap. It seems to me that would also affect the feedback sense coil. Non the less, I think the servo drives are the way to go - I have 2 of Brian's dual 8" kits, and I love them.
rak306 is offline  
post #15958 of 27131 Old 06-14-2014, 11:03 PM
AVS Special Member
 
DonH50's Avatar
 
Join Date: Feb 2010
Location: Monument CO
Posts: 9,313
Mentioned: 23 Post(s)
Tagged: 0 Thread(s)
Quoted: 1659 Post(s)
Liked: 1205
The loop delay problem I mentioned was with acoustic sensors, which can add 10's of us to ms (or 10's of ms for a mic at the listener's position) delay. As I said, I used a similar servo loop ages ago and agree that such a design can be readily stabilized.

Brian discussed the BL impact at one point; I'm sure he'd be willing to do so again if the post is not easy to find (I did not look tonight -- tired, and this is a big thread!)

I have designed amplifiers and data converter circuits for VHF through W band. I am very familiar with trying to deal with loop delay, and the problem of explaining why an amplifier is a great oscillator...

"After silence, that which best expresses the inexpressible, is music" - Aldous Huxley
DonH50 is offline  
post #15959 of 27131 Old 06-15-2014, 03:35 PM
Advanced Member
 
rak306's Avatar
 
Join Date: Oct 2004
Location: Syracuse NY
Posts: 705
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 372 Post(s)
Liked: 132
Quote:
Originally Posted by DonH50 View Post

...
Brian discussed the BL impact at one point; I'm sure he'd be willing to do so again if the post is not easy to find (I did not look tonight -- tired, and this is a big thread!)
...
I would be interested - if you can find it.

I tried to read this entire thread awhile ago - but I gave up. Then I resorted to searching only on posts from user "Rythmik". Even that list was huge.
rak306 is offline  
post #15960 of 27131 Old 06-16-2014, 07:43 AM
AVS Forum Special Member
 
JT78681's Avatar
 
Join Date: Apr 2012
Location: Austin, Texas
Posts: 3,152
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 1290 Post(s)
Liked: 813
So I've been running my FV15HP's in 1 port mode 3db hot <60hz, 14hz/high dampening (using PEQ on amp) for a few days now. I think I have finally found the right combination of settings that I will stick with for a while. I feel like the subs aren't being over worked and retain their composure throughout the entire frequency range. It's simply tight and controlled, but punishing down low. I can only imagine what you guys with dedicated theater rooms are experiencing.

Display - LG 65EF9500
Receiver - Denon 4311CI
Speakers - Klipsch RF-82 II's, RC-62 II, RB-61 II's
Subs - Rythmik FV15HP's
JT78681 is offline  
Sponsored Links
Advertisement
 
Reply Subwoofers, Bass, and Transducers

Tags
f12g subwoofer , lv12r , Rythmik , Rythmik Audio , Rythmik Audio F12 Direct Servo Subwoofer , Rythmik Audio F15 Subwoofer , servo sub

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