Official SpeakerPower amplifier thread - AVS Forum | Home Theater Discussions And Reviews
Forum Jump: 
 88Likes
Reply
 
Thread Tools
post #1 of 224 Old 04-02-2016, 03:28 PM - Thread Starter
AVS Forum Special Member
 
lukeamdman's Avatar
 
Join Date: May 2011
Location: Burnsville, MN
Posts: 3,455
Mentioned: 127 Post(s)
Tagged: 2 Thread(s)
Quoted: 1191 Post(s)
Liked: 1422
Official SpeakerPower amplifier thread

www.speakerpower.net


SpeakerPower recently released a new line of rack mount and plate amps that are geared toward the DIY crowd. While their amps used to have strictly SpeakOn, PowerCon, and XLR with no user-controllable EQ, crossovers, or phase control now have binding posts, NEMA-15 power cords, RCA inputs, and all the aforementioned signal controls.

Also making things more appealing is a recent price drop across the board!

I know Brian frequents most of the forums out there, so I’m sure any questions here will be answered.


My first experience with SpeakerPower amps was when Jeff Permanian (JTR Speakers) brought his highly acclaimed Orbit Shifter LFU to my first AVS GTG in 2013. I couldn’t believe a plate amp (SP1-4000) could bring a single enclosure to such immense SPL levels (tested by data-bass.com to exceed 130db).


These amps are also used by Seaton Sound, Danley Sound Labs, Power Sound Audio, and Deep Sea Sound to name a few.


I purchased my first SpeakerPower amp (rack mount SP2-12000) at the end of 2014 to drive a pair of Othorn tapped horn subwoofers (designed by Josh Ricci of data-bass.com) loaded with B&C 21-IPAL drivers. These drivers have an unusually low Re of 0.7ohm, and even though the impedance drops to ~1.1ohm while loaded in an Othorn, the SP2-12000 has effortlessly drove these subs all while remaining cold to the touch. In the last ~1.5 years I’ve only seen the fans actually turn on two or three times. I’ve measured SPL levels just north of 139db at the seats in my HT room with just these two subs and a single SpeakerPower amp!


I recently purchased another SP2-12000 to power my latest project of (8) sealed 21” drivers and I’m thrilled with the results. I encourage anyone else using these amplifiers to post their experiences here!
eng-399 and 18Hurts like this.

Last edited by lukeamdman; 04-02-2016 at 07:38 PM.
lukeamdman is offline  
Sponsored Links
Advertisement
 
post #2 of 224 Old 04-02-2016, 05:24 PM - Thread Starter
AVS Forum Special Member
 
lukeamdman's Avatar
 
Join Date: May 2011
Location: Burnsville, MN
Posts: 3,455
Mentioned: 127 Post(s)
Tagged: 2 Thread(s)
Quoted: 1191 Post(s)
Liked: 1422
What good is a thread without some pictures!


First SP2-12000 purchased in 2014:












10awg L6-30P vs. 14awg NEMA 5-15P:











SP2-12000 that arrived this week:












muzz, filtor1, Oval56 and 2 others like this.
lukeamdman is offline  
post #3 of 224 Old 04-02-2016, 05:41 PM
AVS Forum Special Member
 
NWCgrad's Avatar
 
Join Date: Feb 2010
Location: Frederick, MD
Posts: 3,556
Mentioned: 51 Post(s)
Tagged: 0 Thread(s)
Quoted: 1261 Post(s)
Liked: 1280
There's a crap ton of power in that amp rack!!!!!!

______________________________________
Home Theater:
http://www.avsforum.com/forum/15-gen...sement-ht.html
NWCgrad is online now  
 
post #4 of 224 Old 04-03-2016, 09:04 AM
AVS Forum Special Member
 
murphy2112's Avatar
 
Join Date: Oct 2005
Location: Chicago, IL
Posts: 1,310
Mentioned: 25 Post(s)
Tagged: 1 Thread(s)
Quoted: 606 Post(s)
Liked: 337
Question: since the 240v spec has a lot more power than the 120v, if I have the standard 3-wire 240v U.S. home wiring, could I just run a 30-amp 240v connection (two 120v legs plus a common ground) to get the higher power?
murphy2112 is offline  
post #5 of 224 Old 04-03-2016, 09:10 AM
AVS Forum Special Member
 
goonstopher's Avatar
 
Join Date: Dec 2008
Location: NJ near NYC
Posts: 4,816
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 315 Post(s)
Liked: 61
These are definitely great but the price makes them only for those with money to spare... Wish I could afford
goonstopher is offline  
post #6 of 224 Old 04-03-2016, 09:40 AM
AVS Forum Special Member
 
N8DOGG's Avatar
 
Join Date: Dec 2003
Location: Canada
Posts: 7,140
Mentioned: 37 Post(s)
Tagged: 1 Thread(s)
Quoted: 1057 Post(s)
Liked: 1144
We have the exact same carpet..... lol weird

Blasting brown notes for 10 years and counting!

N8DOGG is online now  
post #7 of 224 Old 04-03-2016, 09:57 AM - Thread Starter
AVS Forum Special Member
 
lukeamdman's Avatar
 
Join Date: May 2011
Location: Burnsville, MN
Posts: 3,455
Mentioned: 127 Post(s)
Tagged: 2 Thread(s)
Quoted: 1191 Post(s)
Liked: 1422
Quote:
Originally Posted by murphy2112 View Post
Question: since the 240v spec has a lot more power than the 120v, if I have the standard 3-wire 240v U.S. home wiring, could I just run a 30-amp 240v connection (two 120v legs plus a common ground) to get the higher power?
Yes, and that's exactly what I did.

I had already run a 30A circuit (10awg wire) for my Crest CC5500 amp, so I bought one of these breakers and used the white wire (neutral) for the other 120v "hot" wire. Bingo, two 120v lines plus a ground.

http://www.homedepot.com/p/Siemens-3...230U/100002289

I also used this for the outlet:

http://www.homedepot.com/p/30-Amp-25...CCV3/100117946

However, if you have a 20A circuit, you could do the same with a 20A dual breaker.

Last edited by lukeamdman; 04-03-2016 at 12:18 PM.
lukeamdman is offline  
post #8 of 224 Old 04-04-2016, 04:55 AM
AVS Forum Special Member
 
murphy2112's Avatar
 
Join Date: Oct 2005
Location: Chicago, IL
Posts: 1,310
Mentioned: 25 Post(s)
Tagged: 1 Thread(s)
Quoted: 606 Post(s)
Liked: 337
Quote:
Originally Posted by lukeamdman View Post
Yes, and that's exactly what I did.

I had already run a 30A circuit (10awg wire) for my Crest CC5500 amp, so I bought one of these breakers and used the white wire (neutral) for the other 120v "hot" wire. Bingo, two 120v lines plus a ground.

http://www.homedepot.com/p/Siemens-3...230U/100002289

I also used this for the outlet:

http://www.homedepot.com/p/30-Amp-25...CCV3/100117946

However, if you have a 20A circuit, you could do the same with a 20A dual breaker.


Cool. I have a 20-amp now that everything run on, but I may run another 20-amp line. All my power cords are NEMA-15, but I have 5 power amplifiers and all of them combined can pull more power than a single 20-amp, although I've never tripped a breaker.
murphy2112 is offline  
post #9 of 224 Old 04-04-2016, 08:18 AM
Member
 
SpeakerPower's Avatar
 
Join Date: Jan 2013
Posts: 86
Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 46 Post(s)
Liked: 96
Make sure you only try this if you have a dedicated single outlet on it's own breaker. Most houses string several duplex outlets on one 20A breaker. All of them will have 240VAC on them if this mod is done and will blow up most 120V gear plugged into them. Also to comply with National Electrical Code the wires carrying 120VAC should be black or red, not white. But I have heard of worse things being done. Like lifting grounds!
stegen and lukeamdman like this.
SpeakerPower is offline  
post #10 of 224 Old 04-04-2016, 08:33 AM - Thread Starter
AVS Forum Special Member
 
lukeamdman's Avatar
 
Join Date: May 2011
Location: Burnsville, MN
Posts: 3,455
Mentioned: 127 Post(s)
Tagged: 2 Thread(s)
Quoted: 1191 Post(s)
Liked: 1422
Quote:
Originally Posted by SpeakerPower View Post
Make sure you only try this if you have a dedicated single outlet on it's own breaker. Most houses string several duplex outlets on one 20A breaker. All of them will have 240VAC on them if this mod is done and will blow up most 120V gear plugged into them. Also to comply with National Electrical Code the wires carrying 120VAC should be black or red, not white. But I have heard of worse things being done. Like lifting grounds!

Really good points!


Lucky for me all 7 circuits are dedicated just to the amp rack.


During inspection on the electrical, I was required to put red electrical tape on each end of the white wires (in the breaker panel and in the outlet) to comply with code on the 240v runs.
lukeamdman is offline  
post #11 of 224 Old 04-04-2016, 11:41 AM
Advanced Member
 
stegen's Avatar
 
Join Date: Dec 2003
Location: La Crescent, MN
Posts: 579
Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 95 Post(s)
Liked: 89
I wouldnt use a 2 pole breaker for a 240 line. if something goes wrong with one line, the other will still be hot and you may not realize it. It should be a single pole breaker for safety.
stegen is offline  
post #12 of 224 Old 04-04-2016, 12:20 PM - Thread Starter
AVS Forum Special Member
 
lukeamdman's Avatar
 
Join Date: May 2011
Location: Burnsville, MN
Posts: 3,455
Mentioned: 127 Post(s)
Tagged: 2 Thread(s)
Quoted: 1191 Post(s)
Liked: 1422
Quote:
Originally Posted by stegen View Post
I wouldnt use a 2 pole breaker for a 240 line. if something goes wrong with one line, the other will still be hot and you may not realize it. It should be a single pole breaker for safety.

You have to use a 2 pole breaker. However, the two breakers are connected so if one trips they both do.
lukeamdman is offline  
post #13 of 224 Old 04-04-2016, 12:28 PM
Advanced Member
 
stegen's Avatar
 
Join Date: Dec 2003
Location: La Crescent, MN
Posts: 579
Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 95 Post(s)
Liked: 89
Then i must be thinking of 2 seperate breakers for a 240 line. Sorry, in the middle of training ATM. I was thinking of tandem breakers
stegen is offline  
post #14 of 224 Old 04-10-2016, 07:48 AM - Thread Starter
AVS Forum Special Member
 
lukeamdman's Avatar
 
Join Date: May 2011
Location: Burnsville, MN
Posts: 3,455
Mentioned: 127 Post(s)
Tagged: 2 Thread(s)
Quoted: 1191 Post(s)
Liked: 1422
Well, I ordered a 3rd SP2-12000 last week. Anything less on the Othorns just left too much of their potential unused.
Scott Simonian likes this.
lukeamdman is offline  
post #15 of 224 Old 04-10-2016, 08:18 AM
AVS Forum Special Member
 
murphy2112's Avatar
 
Join Date: Oct 2005
Location: Chicago, IL
Posts: 1,310
Mentioned: 25 Post(s)
Tagged: 1 Thread(s)
Quoted: 606 Post(s)
Liked: 337
So the $2,650 12000-DSP Amp looks quite nice in terms of power output. Where are the distortion figures though? I would most certainly want 240v to take advantage of the power output, otherwise you might as well get a Behringer or Crown instead for the same 120v power levels.
murphy2112 is offline  
post #16 of 224 Old 04-10-2016, 05:04 PM
AVS Forum Special Member
 
BassThatHz's Avatar
 
Join Date: Apr 2008
Location: Northern Okan range (NW Cascades region)
Posts: 7,511
Mentioned: 86 Post(s)
Tagged: 0 Thread(s)
Quoted: 2208 Post(s)
Liked: 1858
Quote:
Originally Posted by murphy2112 View Post
Where are the distortion figures though?
No half-decent SS amplifier produces more than 0.1% distortion until clipping. Which is plenty clean enough for subwoofer duty.
Nobody is gonna power a tweeter with a 12kW amp either (nobody should at least...)

Look at data-bass, even the best drivers produce 1% distortion all the time (or MUCH MORE...)
The only time you might hear an amplifier through a subwoofer cone is if it is clipping, limiting, or about to explode.

If you want to power tweeters, buy a McIntosh for the expensive-end or Emotiva for the cheap-end. I would avoid using pro amps for powering tweeters if you can, especially multi-kW pro amps, they have horrible noisefloors (and fans too).
The only reason to use pro amps for tweeters is to save money or maybe rackspace. (I use clone amps for tweeters for those reasons, it's not really ideal, but it does get the job done...)
BassThatHz is online now  
post #17 of 224 Old 04-10-2016, 05:23 PM
AVS Forum Special Member
 
murphy2112's Avatar
 
Join Date: Oct 2005
Location: Chicago, IL
Posts: 1,310
Mentioned: 25 Post(s)
Tagged: 1 Thread(s)
Quoted: 606 Post(s)
Liked: 337
Quote:
Originally Posted by BassThatHz View Post
No half-decent SS amplifier produces more than 0.1% distortion until clipping. Which is plenty clean enough for subwoofer duty.

Nobody is gonna power a tweeter with a 12kW amp either (nobody should at least...)



Look at data-bass, even the best drivers produce 1% distortion all the time (or MUCH MORE...)

The only time you might hear an amplifier through a subwoofer cone is if it is clipping, limiting, or about to explode.



If you want to power tweeters, buy a McIntosh for the expensive-end or Emotiva for the cheap-end. I would avoid using pro amps for powering tweeters if you can, especially multi-kW pro amps, they have horrible noisefloors (and fans too).

The only reason to use pro amps for tweeters is to save money or maybe rackspace. (I use clone amps for tweeters for those reasons, it's not really ideal, but it does get the job done...)


I'm not really looking to power tweeters. I'm just saying that I didn't see THD listed anywhere in the specs. Maybe I missed it? I've seen some amps show power at .3%, or .5%, or 1%. I don't see the THD figures in the specs on these.
murphy2112 is offline  
post #18 of 224 Old 04-10-2016, 05:43 PM - Thread Starter
AVS Forum Special Member
 
lukeamdman's Avatar
 
Join Date: May 2011
Location: Burnsville, MN
Posts: 3,455
Mentioned: 127 Post(s)
Tagged: 2 Thread(s)
Quoted: 1191 Post(s)
Liked: 1422
Quote:
Originally Posted by murphy2112 View Post
I'm not really looking to power tweeters. I'm just saying that I didn't see THD listed anywhere in the specs. Maybe I missed it? I've seen some amps show power at .3%, or .5%, or 1%. I don't see the THD figures in the specs on these.
I think I remember seeing 0.1%, but I'm sure Brian will chime in.
lukeamdman is offline  
post #19 of 224 Old 04-10-2016, 06:32 PM
AVS Forum Special Member
 
BassThatHz's Avatar
 
Join Date: Apr 2008
Location: Northern Okan range (NW Cascades region)
Posts: 7,511
Mentioned: 86 Post(s)
Tagged: 0 Thread(s)
Quoted: 2208 Post(s)
Liked: 1858
I'd guess that the difference in power output between 0.1% and 1.0% is less than 1db, since 6kW vs 3kW is only 3db, which is 50% less power.
When your ears are screaming in pain from 12kW and 140db, an extra 1db here or there isn't gonna make a big difference in the pain level experienced. 3db probably would though...

Last edited by BassThatHz; 04-10-2016 at 06:35 PM.
BassThatHz is online now  
post #20 of 224 Old 04-11-2016, 08:07 AM
Member
 
SpeakerPower's Avatar
 
Join Date: Jan 2013
Posts: 86
Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 46 Post(s)
Liked: 96
Comments above are correct. The power numbers specified are at 1%, but just below that level the distortion is below 0.1%. Your ability to perceive distortion is greatly reduced at sub frequencies. And the distortion of any amp above the clipping level is in the 10% to 100% range unless a clipping eliminator circuit is used. Our sub amps have such a circuit that is not defeatable.

Comparing a Beringer 12000 to my 12000 is not even close in many ways. B is a 20 year old design with no post filter feedback and does not make anywhere near the power specified.

The 120VAC 20A service is not as big a limitation as you might think when you discover that for 10 seconds a 20A breaker can pass 80A. And for shorter periods, even more.

Breaker curves
SpeakerPower is offline  
post #21 of 224 Old 04-11-2016, 10:26 AM
AVS Forum Special Member
 
rhodesj's Avatar
 
Join Date: Apr 2005
Posts: 1,952
Mentioned: 35 Post(s)
Tagged: 0 Thread(s)
Quoted: 922 Post(s)
Liked: 508
Can a SP2-12000 run on 120V, or is it 240V only?
rhodesj is online now  
post #22 of 224 Old 04-11-2016, 05:20 PM
AVS Forum Special Member
 
lz7j's Avatar
 
Join Date: Dec 2006
Location: Toronto, ON
Posts: 1,047
Mentioned: 42 Post(s)
Tagged: 0 Thread(s)
Quoted: 688 Post(s)
Liked: 669
Quote:
Originally Posted by rhodesj View Post
Can a SP2-12000 run on 120V, or is it 240V only?


@SpeakerPower - hi Brian, can you please offer your feedback? I called last week and spoke to Alex regarding your sp-8000. I was told I'd need a 30A service for it. Would I be able to fully utilize the sp8000 on a dedicated 20A and sp12000 on a 30A/120? Looking forward to upgrading my 20 year old tech behringers!
lz7j is offline  
post #23 of 224 Old 04-11-2016, 06:30 PM - Thread Starter
AVS Forum Special Member
 
lukeamdman's Avatar
 
Join Date: May 2011
Location: Burnsville, MN
Posts: 3,455
Mentioned: 127 Post(s)
Tagged: 2 Thread(s)
Quoted: 1191 Post(s)
Liked: 1422
Quote:
Originally Posted by rhodesj View Post
Can a SP2-12000 run on 120V, or is it 240V only?

It can run on 120v, but at a loss of output.


http://www.speakerpower.net/specifications.html


The highlighted section is the power specs with the sp2-12000/sp2-6400 on 120v.
lukeamdman is offline  
post #24 of 224 Old 04-11-2016, 06:33 PM
Member
 
SpeakerPower's Avatar
 
Join Date: Jan 2013
Posts: 86
Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 46 Post(s)
Liked: 96
Quote:
Originally Posted by lz7j View Post
@SpeakerPower - hi Brian, can you please offer your feedback? I called last week and spoke to Alex regarding your sp-8000. I was told I'd need a 30A service for it. Would I be able to fully utilize the sp8000 on a dedicated 20A and sp12000 on a 30A/120? Looking forward to upgrading my 20 year old tech behringers!
This is a common question. And since an amplifier is a variable consumption device, there is not just one simple answer.

Answer 1. You operate industrial shaker tables and need 10-200Hz sine waves near full power for hours at a time. You need 240VAC 30A service for 1 x SP2-12000.

Answer 2. I listen to light classical music at a level where I never even tickle the clip light. You can put 10 x SP2-12000 on a single 15A 120VAC service.

Most people lie somewhere in between. Pro PA doing EDM at an outdoor festival is toward the high end, Home Theater, even with demanding sound effects is towards the low end.

Since this is the AVS forum, I would say you will be just fine with a SP2-8000 even with demanding sound effects as long as it has it's own 15-20A circuit. If you are a crazy person (and you know who you are) and want a no compromise mega system that will deconstruct your house then the SP2-12000 on a dedicated 20-30A breaker will do the job quite nicely.
SpeakerPower is offline  
post #25 of 224 Old 04-11-2016, 06:38 PM
Member
 
SpeakerPower's Avatar
 
Join Date: Jan 2013
Posts: 86
Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 46 Post(s)
Liked: 96
Quote:
Originally Posted by lukeamdman View Post
It can run on 120v, but at a loss of output.


http://www.speakerpower.net/specifications.html


The highlighted section is the power specs with the sp2-12000/sp2-6400 on 120v.
That's correct. While the SP2-12000 will work on 120VAC, the SP2-8000 is designed for 120VAC and will deliver more power then the SP2-12000 at that voltage. So unless there is some other factor, like you have a portable system and want to be able to plug it in anywhere, there is no reason to operate the SP2-12000 at 120VAC.
SpeakerPower is offline  
post #26 of 224 Old 04-12-2016, 11:06 AM
Senior Member
 
AV Hack's Avatar
 
Join Date: Jan 2015
Location: Greater Bay Area, CA USA
Posts: 408
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 140 Post(s)
Liked: 72
Quote:
Originally Posted by SpeakerPower View Post

If you are a crazy person (and you know who you are) and want a no compromise mega system that will deconstruct your house then the SP2-12000 on a dedicated 20-30A breaker will do the job quite nicely.
I LOL'd. An unfortunately high percentage here could fit that description.
lukeamdman likes this.

Working on the next one...
AV Hack is offline  
post #27 of 224 Old 04-12-2016, 06:08 PM
AVS Forum Special Member
 
lz7j's Avatar
 
Join Date: Dec 2006
Location: Toronto, ON
Posts: 1,047
Mentioned: 42 Post(s)
Tagged: 0 Thread(s)
Quoted: 688 Post(s)
Liked: 669
Quote:
Originally Posted by SpeakerPower View Post
That's correct. While the SP2-12000 will work on 120VAC, the SP2-8000 is designed for 120VAC and will deliver more power then the SP2-12000 at that voltage. So unless there is some other factor, like you have a portable system and want to be able to plug it in anywhere, there is no reason to operate the SP2-12000 at 120VAC.
Thanks Brian. I will most likely order 2 of your sp8000. I need to talk to Jeff at jtr first to see if he can use and upload the dsp configuration on the sp8000 for the OS pro. BTW, do you have any literature for the new HT models? Was wondering if it has the ability to implement a high pass filter.
lz7j is offline  
post #28 of 224 Old 04-21-2016, 06:43 PM - Thread Starter
AVS Forum Special Member
 
lukeamdman's Avatar
 
Join Date: May 2011
Location: Burnsville, MN
Posts: 3,455
Mentioned: 127 Post(s)
Tagged: 2 Thread(s)
Quoted: 1191 Post(s)
Liked: 1422
Each SP2-12000 has it's own dedicated 240v 30A circuit, so that's 180A worth of breakers just for those 3 amps!

homeskizzle likes this.
lukeamdman is offline  
post #29 of 224 Old 04-21-2016, 07:25 PM
AVS Forum Special Member
 
lz7j's Avatar
 
Join Date: Dec 2006
Location: Toronto, ON
Posts: 1,047
Mentioned: 42 Post(s)
Tagged: 0 Thread(s)
Quoted: 688 Post(s)
Liked: 669
Quote:
Originally Posted by lukeamdman View Post
Each SP2-12000 has it's own dedicated 240v 30A circuit, so that's 180A worth of breakers just for those 3 amps!

man, that is a lot of fire power in that rack! can you please provide a breakdown on what each of those are powering at what load?
lz7j is offline  
post #30 of 224 Old 04-21-2016, 07:50 PM - Thread Starter
AVS Forum Special Member
 
lukeamdman's Avatar
 
Join Date: May 2011
Location: Burnsville, MN
Posts: 3,455
Mentioned: 127 Post(s)
Tagged: 2 Thread(s)
Quoted: 1191 Post(s)
Liked: 1422
Quote:
Originally Posted by lz7j View Post
man, that is a lot of fire power in that rack! can you please provide a breakdown on what each of those are powering at what load?

SpeakerPower SP2-12000: Othorns w/21-IPAL, 0.7ohm per channel (dcr)
(2) SpeakerPower SP2-12000: dual-opposed sealed 21s, 1.5ohm per channel x4 (dcr)
Crest CC4000: Quad AE TD18H+, 4ohm per channel
Lab Gruppen IPD 2400: BMS 4594ND, 8ohm per channel
Crown XLS 2500: Active center (AE TD15M, Denovo DNA-360), 8ohm per channel
Behringer iNuke NU4-6000: Radian 5210 surrounds, 8ohm per channel
lz7j, joebuddyguy and Oval56 like this.
lukeamdman is offline  
Sponsored Links
Advertisement
 
Reply DIY Speakers and Subs



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