zstar
Minor Hero
Posts: 60 
|
Post by zstar on Mar 23, 2010 12:25:41 GMT -5
How is calibrating multiple subs handled by the UMC
The manual does not discuss
|
|
DYohn
Emo VIPs 
Posts: 18,493
|
Post by DYohn on Mar 23, 2010 12:41:58 GMT -5
How is calibrating multiple subs handled by the UMC The manual does not discuss There is one subwoofer output, so it considers whatever you have connected to it as one channel for settings. |
|
zstar
Minor Hero
Posts: 60
|
Post by zstar on Mar 23, 2010 13:15:22 GMT -5
I understand how to connect multiple subs.
I was asking if there were instructions on how to calibrate multiple subs.
I was reading the manual for the AVM 50
They have a section on how to calibrate multiple subs
I was wondering if their areinstructions using my Radio shack sound meter to manually calibrate multiple subs
|
|
DYohn
Emo VIPs
Posts: 18,493
|
Post by DYohn on Mar 23, 2010 13:52:21 GMT -5
I understand how to connect multiple subs. I was asking if there were instructions on how to calibrate multiple subs. I was reading the manual for the AVM 50 They have a section on how to calibrate multiple subs I was wondering if their areinstructions using my Radio shack sound meter to manually calibrate multiple subs Like I said, the UMC-1 will consider your multiple subs as one channel and set one Xover, one level and one distance based on the summed output at the mic location. Manually calibrating multiple subs so that they are playing at the same levels (or whatever you need them to do) in phase, etc. would be up to you and way beyond the scope of anything the UMC-1 can do on its own. |
|
NorthStar
Seeker Of Truth
"And it stoned me to my soul" - Van Morrison
Posts: 0
|
Post by NorthStar on Mar 23, 2010 23:08:21 GMT -5
I understand how to connect multiple subs. I was asking if there were instructions on how to calibrate multiple subs. I was reading the manual for the AVM 50 They have a section on how to calibrate multiple subs I was wondering if their areinstructions using my Radio shack sound meter to manually calibrate multiple subs zstar, Just follow the instructions from the AVM 50 manual, and apply the recipe to the UMC-1 when using a Y adaptor for multiple subs, quite easy. * The main thing here is this: first, always balance your two (or more) subs (using a Shack meter or another form of level measurement, and a test disc with low frequencies 'subwoofer' band limited pink noises, like "Video Essentials" or "AVIA" or others of that sort ) to be equally at the same volume levels, same Phase, same x-over settings (Bypass or highest setting); and then run your Auto Room Calibration gizmo. * When using more than one sub, always start with the Gain control (volume level from the subs themselves) set to about 1/4 of its knob' position. And for "better" sense of security (day & night), and other positive attributes that I simply don't have all the time to discuss here (just trust me on that & simply take my word for it), use the two Low Level Main/In RCA jacks (L & R) from both (or more) subwoofers, again using Y adaptors. Hope this helps, Bob, aka LOTR P.S. If you need more expertise and details on this, please don't be afraid to ask me. But right from the bat I'd say this to you: ARC1 is great, Audyssey MultEQ PRO is great, SVSound AS-EQ-1 SubEQ is great (for EQing two separate subs), TRINNOV is great, and Onkyo/Integra models with dual separate sub EQ is also great. Pick your poison carefully, and it will catapult you to that other yet unknown audio dimension called AUDIO NIRVANA or the HOLY GRAIL of AUDIO BLISS. Add to that 'Odyssee Motion Simulator' (developed in Longueuil, Montreal, a Quebec-based D-BOX Technology, Inc.) and you are still in a totally another higher audio stratosphere alltogether, this one called AZUDIO MAYHEM, like the new blue azure of the highest sky just before you hit the ozone layer of the atmosphere (so you're still grounded, your two feet in our planet, but your brains have been transported into orbit, to the 'Andromeda' galaxy where Black is the presence of all colors and dimensions, nine of them to be exact, and in a rainbow of total Darkness with full spaciousness & qualitative ambiance). >> Hope you didn't take me too seriously, ...because I was.  |
|
ntrain42
Emo VIPs
Smoke me a kipper, I'll be home before breakfast!
Posts: 2,969
|
Post by ntrain42 on Mar 24, 2010 15:55:10 GMT -5
I understand how to connect multiple subs. I was asking if there were instructions on how to calibrate multiple subs. I was reading the manual for the AVM 50 They have a section on how to calibrate multiple subs I was wondering if their areinstructions using my Radio shack sound meter to manually calibrate multiple subs group your 2 subs together, then phase, eq curve, gain etc. will be identical between them. No need to seperately eq each sub......... |
|
|
|
Post by markus on Mar 25, 2010 20:38:02 GMT -5
group your 2 subs together, then phase, eq curve, gain etc. will be identical between them. No need to seperately eq each sub......... Multiple subs can be EQed as one AFTER they have been optimized in level and delay. Correct optimization does NOT just "align" crossover slopes, delay and gain to that of the main speakers. You might want to read www.harman.com/EN-US/OurCompany/Technologyleadership/Documents/Scientific%20Publications/13680.pdfBasically the transfer function of each speaker to the listening position(s) is measured. From that transfer function the best settings is found by a brute force method. As far as I know Harman has a patent on that or tries to get one. A similar approach that is not patented has been proposed by Earl Geddes: mehlau.net/audio/multisub_geddes/ So the best approach to subwoofer calibration is to built it into an AVR like the UMC-1. That would ensure that the crossover region between the subwoofers and the other loudspeakers is optimized too - something most low frequency optimizations simply ignore. Unfortunately the UMC-1 seems not to be able to a) optimize multiple subwoofers and b) apply useful EQs although the platform seems to be capable of it. Best, Markus |
|
Mister L'fe
Emo VIPs
There is nothing in the dark that isn't there when the lights are on.
Posts: 417
|
Post by Mister L'fe on Mar 26, 2010 7:48:41 GMT -5
And there are pre-pros that will calibrate at least 2 subwoofers if it is something you need.
|
|
ntrain42
Emo VIPs
Smoke me a kipper, I'll be home before breakfast!
Posts: 2,969
|
Post by ntrain42 on Mar 26, 2010 17:17:15 GMT -5
group your 2 subs together, then phase, eq curve, gain etc. will be identical between them. No need to seperately eq each sub......... Multiple subs can be EQed as one AFTER they have been optimized in level and delay. Correct optimization does NOT just "align" crossover slopes, delay and gain to that of the main speakers. You might want to read www.harman.com/EN-US/OurCompany/Technologyleadership/Documents/Scientific%20Publications/13680.pdfBasically the transfer function of each speaker to the listening position(s) is measured. From that transfer function the best settings is found by a brute force method. As far as I know Harman has a patent on that or tries to get one. A similar approach that is not patented has been proposed by Earl Geddes: mehlau.net/audio/multisub_geddes/ So the best approach to subwoofer calibration is to built it into an AVR like the UMC-1. That would ensure that the crossover region between the subwoofers and the other loudspeakers is optimized too - something most low frequency optimizations simply ignore. Unfortunately the UMC-1 seems not to be able to a) optimize multiple subwoofers and b) apply useful EQs although the platform seems to be capable of it. Best, Markus Hehe, if you place both subs right next to each other, then you cansider them as "one" unit. No need to individually calibrate each one. This is splitting hairs that really gains no benefit. Take for example my 2 15" subs. THey sit right next to each other, gains(level match) between them is identical. So is phase(they are the same distance from the seating positions). One sub eq channel is able to eq them out correctly. I mean, if you want to make it more complex than it needs to be, then so be it. But when you group your subs together, they act as one big single unit literally. Obviously, if the subs are placed in seperate locations, then individual tuning is a must. So for those with only using a .1 channel system, they should probably group them together, unless they have good calibration instrumentation. And subs with variable phase, and some type of built in EQ system would be a benefit as well. |
|
edvb
Minor Hero
Posts: 52
|
Post by edvb on Mar 26, 2010 20:48:18 GMT -5
And if I am correct a 6Db gain with two subs stacked or side by side. Seperated about a 3Db gain.
|
|
ntrain42
Emo VIPs
Smoke me a kipper, I'll be home before breakfast!
Posts: 2,969
|
Post by ntrain42 on Mar 26, 2010 20:52:15 GMT -5
And if I am correct a 6Db gain with two subs stacked or side by side. Seperated about a 3Db gain. They dont need to be stacked side by side for an average in room 6db gain, thats a misconception. If you have both subs seperated and have them placed well and "in phase" at the seated position you can and will still pick up a solid 6db. But if your getting sound cancellation out of them by not having the phase set properly along with poor positioning, then of course your going to get less than optimal results. |
|
|
|
Post by markus on Mar 27, 2010 17:13:31 GMT -5
Hehe, if you place both subs right next to each other, then you cansider them as "one" unit. No need to individually calibrate each one. This is splitting hairs that really gains no benefit. Take for example my 2 15" subs. THey sit right next to each other, gains(level match) between them is identical. So is phase(they are the same distance from the seating positions). One sub eq channel is able to eq them out correctly. I mean, if you want to make it more complex than it needs to be, then so be it. But when you group your subs together, they act as one big single unit literally. Obviously, if the subs are placed in seperate locations, then individual tuning is a must. So for those with only using a .1 channel system, they should probably group them together, unless they have good calibration instrumentation. And subs with variable phase, and some type of built in EQ system would be a benefit as well. Grouping subwoofers doesn't help reduce the seat to seat variance. They basically act as one subwoofer. To EQ subs correctly one would need to have more precise control than the UMC-1 offers. An EQ won't help getting rid of modal dips and it will only work for a single listener location. Welti has shown, that distributing multiple low frequency sources significantly reduce the seat to seat variance. After that kind of optimization an EQ can be used to correct frequency response at multiple listener locations. |
|
|
|
Post by markus on Mar 27, 2010 17:30:59 GMT -5
And if I am correct a 6Db gain with two subs stacked or side by side. Seperated about a 3Db gain. These kind of calculations are meaningless in acoustically small rooms because the room's modal behavior introduces frequency variations as high as 20 to 30 dB. |
|
|
|
Post by Porscheguy on Mar 28, 2010 9:32:19 GMT -5
How does the UMC-1 handle a 2nd sub in zone 2? Is there a way to adjust the level of that output so it differs from the main theater?
|
|
DYohn
Emo VIPs
Posts: 18,493
|
Post by DYohn on Mar 28, 2010 10:01:55 GMT -5
How does the UMC-1 handle a 2nd sub in zone 2? Is there a way to adjust the level of that output so it differs from the main theater? The Zone 2 output is full-range stereo. The only control you have over it from the UMC-1 is source and volume. |
|
|
|
Post by Porscheguy on Mar 28, 2010 10:27:31 GMT -5
How does the UMC-1 handle a 2nd sub in zone 2? Is there a way to adjust the level of that output so it differs from the main theater? The Zone 2 output is full-range stereo. The only control you have over it from the UMC-1 is source and volume. Thats too bad. Thats the same as my pre/pro now. The main theater volume controls the sub output so you can never get the proper balance in zone 2. Once the UMC-1 is installed I'm going to have to use the speaker level inputs on the zone 2 sub which means more wiring as the sub is not close the the speakers. IMHO, zone 2 needs it's own sub out.......... |
|
ntrain42
Emo VIPs
Smoke me a kipper, I'll be home before breakfast!
Posts: 2,969
|
Post by ntrain42 on Mar 28, 2010 10:34:06 GMT -5
Hehe, if you place both subs right next to each other, then you cansider them as "one" unit. No need to individually calibrate each one. This is splitting hairs that really gains no benefit. Take for example my 2 15" subs. THey sit right next to each other, gains(level match) between them is identical. So is phase(they are the same distance from the seating positions). One sub eq channel is able to eq them out correctly. I mean, if you want to make it more complex than it needs to be, then so be it. But when you group your subs together, they act as one big single unit literally. Obviously, if the subs are placed in seperate locations, then individual tuning is a must. So for those with only using a .1 channel system, they should probably group them together, unless they have good calibration instrumentation. And subs with variable phase, and some type of built in EQ system would be a benefit as well. Grouping subwoofers doesn't help reduce the seat to seat variance. They basically act as one subwoofer. To EQ subs correctly one would need to have more precise control than the UMC-1 offers. An EQ won't help getting rid of modal dips and it will only work for a single listener location. Welti has shown, that distributing multiple low frequency sources significantly reduce the seat to seat variance. After that kind of optimization an EQ can be used to correct frequency response at multiple listener locations. Well thats funny.......I have both my subs together, and I dont have any "seat to seat variance" at all. And I dont even have the ability to use the sub EQ on the UMC-1 yet. I only have the single band PEQ available from my subs. I have no peaks or dips at any of the seated positions at all. Though I agree with the pricinciples in a general manner that your stating, its not the only way to garentee a larger flat sweetspot for sub response. |
|
|
|
Post by tchaik on Mar 28, 2010 10:34:23 GMT -5
ergo, the xmc
tchaik...............
|
|
ntrain42
Emo VIPs
Smoke me a kipper, I'll be home before breakfast!
Posts: 2,969
|
Post by ntrain42 on Mar 28, 2010 10:46:24 GMT -5
The Zone 2 output is full-range stereo. The only control you have over it from the UMC-1 is source and volume. Thats too bad. Thats the same as my pre/pro now. The main theater volume controls the sub output so you can never get the proper balance in zone 2. Once the UMC-1 is installed I'm going to have to use the speaker level inputs on the zone 2 sub which means more wiring as the sub is not close the the speakers. IMHO, zone 2 needs it's own sub out.......... Why would zone 2 need a sub out? If you have a second dedicated sub for zone 2(I actually run 2 subs in zone 2)then you can still loop feed it via the stereo zone 2 outputs or run it via speaker level inputs(Your sub should have the ability to use one or the other). SInce zone 2 is obviously for stereo/music listening. The subs gain control obviously will be taken care on the sub itself(along with variable or basic phase), and with one of the manual EQ presets on the UMC-1 you will still have a few bands worth of EQ control for the sub frequencies as well to get a real good in room response curve. For example with my UMC-1/UPA-7 combo. I run my Adcom cd player into the rca CD inputs. Then on the zone 2 output, I run a pair of 50 foot RCA cables to the subs(one to the left, one to the right)inputs. Then I run a pair of 50 foot rca stereo cables back from the subs rca outputs(in which the subs run a 130hz high pass signal to the UPA-7)and into 2 channels of the UPA-7. Then the speaker level outputs on the amp run speaker cable to the Magnepan MMGW's. This way I have a fixed highpass xover to the speakers at 130hz(which is perfect for them)and a variable 12/24db low pass to the subs. So using an rta meter I am able to get a perfect blend with my subs and wall mounted speakers. To finish smoothing out the response curve between the subs and monitors I use manual preset #3 and get rid of any naturally remaining bumps or dips with the accompanying UMC-1 EQ once the gain levels, xover and phase has been set properly. |
|
|
|
Post by Porscheguy on Mar 28, 2010 11:11:19 GMT -5
Thats too bad. Thats the same as my pre/pro now. The main theater volume controls the sub output so you can never get the proper balance in zone 2. Once the UMC-1 is installed I'm going to have to use the speaker level inputs on the zone 2 sub which means more wiring as the sub is not close the the speakers. IMHO, zone 2 needs it's own sub out.......... Why would zone 2 need a sub out? If you have a second dedicated sub for zone 2(I actually run 2 subs in zone 2)then you can still loop feed it via the stereo zone 2 outputs or run it via speaker level inputs(Your sub should have the ability to use one or the other). SInce zone 2 is obviously for stereo/music listening. The subs gain control obviously will be taken care on the sub itself(along with variable or basic phase), and with one of the manual EQ presets on the UMC-1 you will still have a few bands worth of EQ control for the sub frequencies as well to get a real good in room response curve. For example with my UMC-1/UPA-7 combo. I run my Adcom cd player into the rca CD inputs. Then on the zone 2 output, I run a pair of 50 foot RCA cables to the subs(one to the left, one to the right)inputs. Then I run a pair of 50 foot rca stereo cables back from the subs rca outputs(in which the subs run a 130hz high pass signal to the UPA-7)and into 2 channels of the UPA-7. Then the speaker level outputs on the amp run speaker cable to the Magnepan MMGW's. This way I have a fixed highpass xover to the speakers at 130hz(which is perfect for them)and a variable 12/24db low pass to the subs. So using an rta meter I am able to get a perfect blend with my subs and wall mounted speakers. To finish smoothing out the response curve between the subs and monitors I use manual preset #3 and get rid of any naturally remaining bumps or dips with the accompanying UMC-1 EQ once the gain levels, xover and phase has been set properly. I'm just going to use the speaker level inputs on the sub. I didn't want to do that because it means more wiring - I'm using a wireless (Subcast) to send the sub signal to zone 2 now and it works quite well, but again the output is variable as it is controlled but the main volume. Your solution seems tedious and complicated in my view and I'm not going down that road... A dedicated sub out for zone 2 is the easiest way to control the output signal. Unfortunately, most zone 2's are not treated very well for control....they are almost an afterthought...... I hope that changes in time..... |
|
