Germotiva
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Alter Mann über 50 aus Deutschland
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Post by Germotiva on Feb 12, 2021 19:02:03 GMT -5
hi ttoc. yes the dsp is used in carhifi😉. there are very good for homecinema. i have four pieces on the rmc1L🤪. The first test is from the reference output L / R in the dsp. then a summation (L + R routing) on the sub-matrix to the subout. my next step attempt will be LFE in the dsp, than the mono signal, without further routing. Then I test the bass routing LFE + L / R on the sub out. and the LFE on the front L + R. the same is also tested with mono signal. Unfortunately, my English is not that good to be able to explain better what I am testing. I hope you understand what I'm doing. my last attempt with the old umc1 was the subout from umc1 to routing on the 12 "midbass to the surround channel 💪
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Post by ttocs on Feb 12, 2021 20:23:12 GMT -5
I've got a question about HT. Are the bass channels L / R or summed? what is the difference between LFE and low bass? I know in music, everything seems to be mixed to mono below maybe 80hz or so..... I can see this being different for THEATERS where you have much more space and can resolve longer wavelengths, (lower frequency) but in a Home system? Emotiva RMC-1/RMC-1L/XMC-2 processors sum the bass for subwoofers to Mono. The Left Sub out, Center Sub out, and Right Sub out, if all are set for Mono, then Bass Management will send all bass for any speaker setup as Small to these subwoofers, PLUS, the .1 LFE (Low-Frequency Effects channel) bass will also be sent to these subwoofers. The current processors also have a feature for only the Center Sub Output. It can be setup as LFE. This means it will ONLY send LFE Channel bass to the Center Sub and no other bass. When setup this way Bass Management will not send ANY bass from any Small speaker to the Center Subwoofer. LFE is a separate channel. It is not Left, Center, Right, or Surround. (Dolby considers all speakers that are not LCR or Sub to be Surround). The Low-Frequency Effects channel is a additional channel only for low frequency effects. It is not the same as the bass from the Surround Left channel because that speaker is setup as Small, no, that speaker will need Bass Management to decide where that bass will be produced, whether that's a different subwoofer than what is designated to be handling LFE or the same subwoofer as what is designated to be handling LFE, it's all in how the speaker system is setup in the processor. Quoted from Dolby: "What is the LFE channel? 5.1-channel audio consists of five discrete, full range main channels (Left, Center, Right, Left Surround, and Right Surround) plus an optional band-limited Low- Frequency Effects (LFE) channel.
In contrast to the main channels, the LFE channel delivers bass-only information (<120 Hz) and has no direct effect on the perceived directionality of the reproduced soundtrack. Its purpose is to supplement the overall bass content of the program or to ease the burden on the other channels. The LFE channel was originally devised for 70 mm movie productions to deliver a separate bass signal to one or more additional subwoofers placed behind the movie screen. This allowed deep bass effects to be added to movie soundtracks without having to upgrade the existing speakers and amplifiers in the three main screen channels. It also meant that the headroom of the 70 mm magnetic audio recordings would not be taxed at low frequencies, which would have detracted from their loudness capability at mid and high frequencies. Finally, no additional frequency crossovers would need to be retrofitted into existing cinema processors to redirect the bass from the main left, center, and right channels to the subwoofer(s). Taking advantage of the available channel capacity on 70 mm prints to deliver a separate bass effects signal proved to be the most direct, convenient, and economical way to supplement the low- frequency capability of movie soundtracks.
To maintain full compatibility with existing theatres, the Dolby Digital film format includes a separate LFE channel. When movies formatted for the consumer use Dolby Digital, the same tracks as originally produced are usually used, including the LFE track if available. Consumer Dolby Digital products that reproduce multichannel sound must combine the LFE channel in the proper acoustic mixing ratio with the bass from the other channels for proper reproduction.
LFE does not equal subwoofer Dolby Digital programs may include a bass-only LFE channel, but this channel does not correspond directly to a subwoofer output. It is possible for a program to contain an LFE channel, but a decoder may provide no subwoofer output because all of the bass information in the program, including the LFE channel, can be reproduced by the main speakers. The opposite is also true: it is possible for a program to not contain an LFE channel, yet a decoder may provide a subwoofer output because some or all of the main speakers are unable to reproduce the bass information in the program. The difference between the LFE channel and the subwoofer output is that the LFE channel is used to carry additional bass information in the Dolby Digital program while the subwoofer output represents how some or all of the bass information will be reproduced.
The LFE channel carries additional bass information to supplement the bass information in the main channels. The signal in the LFE channel is calibrated during soundtrack production to be able to contribute 10 dB higher SPL than the same bass signal from any one of the screen (front) channels. Even if all three screen channels are active, enough bass could be delivered by the LFE channel alone to bring the theatre’s subwoofer into acoustic balance with the screen channels. This allows filmmakers to unburden the main channels by diverting the strongest bass to the separate LFE channel, as needed. Under the most demanding program conditions, where the bass is fully loading the left, center, and right channels, the LFE channel could increase the bass intensity by up to 6 dB.
The subwoofer output, on the other hand, is bass information from up to all six channels that has been selected to be reproduced by a subwoofer. The specific combination of bass information in the subwoofer output is determined by the bass management settings chosen for that particular playback system’s speakers. For example, in addition to the bass information from the LFE channel, the subwoofer output may include the bass information from the center and surround channels when those speakers are unable to adequately reproduce the bass frequencies.
As can be seen from the above explanation, the terms LFE and subwoofer are not interchangeable, and the distinction between the two terms is very important. Care should be taken to avoid confusion by using these terms appropriately.
Dolby Laboratories, Inc. 100 Potrero Avenue, San Francisco, CA 94103-4813 Telephone 415-558-0200 Fax 415-863-1373 Wootton Bassett, Wiltshire, SN4 8QJ, England Telephone (44) 1793-842100 Fax (44) 1793-842101 www.dolby.com Dolby and the double-D symbol are trademarks of Dolby Laboratories. © 2000 Dolby Laboratories, Inc. Information"
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Post by ttocs on Feb 12, 2021 20:29:15 GMT -5
hi ttoc. yes the dsp is used in carhifi😉. there are very good for homecinema. i have four pieces on the rmc1L🤪. The first test is from the reference output L / R in the dsp. then a summation (L + R routing) on the sub-matrix to the subout. my next step attempt will be LFE in the dsp, than the mono signal, without further routing. Then I test the bass routing LFE + L / R on the sub out. and the LFE on the front L + R. the same is also tested with mono signal. Unfortunately, my English is not that good to be able to explain better what I am testing. I hope you understand what I'm doing. my last attempt with the old umc1 was the subout from umc1 to routing on the 12 "midbass to the surround channel 💪 You have a nice system there! There is a lot of Magnepan owners here. Would you be able to draw a diagram of how your subwoofers are connected? It would help to understand. If not, that is ok, just wondering.
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Post by ttocs on Feb 13, 2021 1:01:28 GMT -5
Here's a couple diagrams of a basic 7.1 speaker setup. Both have the subwoofer connected to the Center Sub output. The first scenario has all Small speakers so the Center Sub = Mono, so Bass Management sends all the Small Speaker bass and the LFE bass to this subwoofer. The second has Fronts = Large, and Center Sub = LFE, so Bass Management sends all the Small Speaker bass to the Large Fronts, and LFE goes only to the Center Sub. There can be more than one subwoofer connected to the Center Sub output, only one is shown for clarity. These diagrams show the basic difference between using Large speakers for BM vs using a Subwoofer for all bass: BM and LFE. Dolby specs the LFE sub to be 31.5Hz-120Hz, and all other channels 40Hz-16kHz. But as we all know the frequencies get much lower with LFE frequencies going below 20Hz, and the Fronts and Surrounds going well below 30Hz. So it's important to remember this when considering setting up your speakers as Large when it results in sending the extra bass for all the Small speakers to the Large speakers. They gotta be happy when doing the extra work!
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Germotiva
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Alter Mann über 50 aus Deutschland
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Post by Germotiva on Feb 13, 2021 3:26:06 GMT -5
Hi ttocs, thank you. The 15“ Subs are CB (pic.280L) -50Hz The 12“ Midbass are CB (pic.80L) 50-180Hz. The Maggis 180-20khz. I still have to mount the mmgw. here is your wish for my setup. I will submit the routing of my tests with the individual measurements. The Backsurround-Center is the Realcentermode(own algorithm no summation) from the Helix-DSP. This is Great 💪 here are all possibilities from the dsp...https://www.audiotec-fischer.de/en/knowledge-base/DSP-PC-Tool/ the real center mode is very interesting. The dsp effect (Dynamic Bass Enhancement) that I use for my midbass and subs is also interesting. as this depends on the volume and is variable. I will show with measurements what this does.
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Post by marcl on Feb 13, 2021 8:57:27 GMT -5
Hi ttocs, thank you. The 15“ Subs are CB (pic.280L) -50Hz The 12“ Midbass are CB (pic.80L) 50-180Hz. The Maggis 180-20khz. I still have to mount the mmgw. here is your wish for my setup. View AttachmentI will submit the routing of my tests with the individual measurements. The Backsurround-Center is the Realcentermode(own algorithm no summation) from the Helix-DSP. This is Great 💪 here are all possibilities from the dsp...https://www.audiotec-fischer.de/en/knowledge-base/DSP-PC-Tool/ the real center mode is very interesting. The dsp effect (Dynamic Bass Enhancement) that I use for my midbass and subs is also interesting. as this depends on the volume and is variable. I will show with measurements what this does. Wow what a cool system! I have 9 Maggies in my system and you have me beat by double! I think the MMGW works well for Atmos tops, even though people think the dispersion is not in the right direction. I just have two for the front tops, but when Atmos top content is playing it comes from the ceiling but not directly from the speakers. Very convincing and blends well in the overall mix. Must be a BIG room!
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Germotiva
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Alter Mann über 50 aus Deutschland
Posts: 90
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Post by Germotiva on Feb 13, 2021 9:38:01 GMT -5
hello marcl thank you, there shouldn't be any competition, the rmc1L offers itself. I am a maggi fan. the first LS were the mmgw. then the mg 1.6 and then the mg 12. Everything bought second-hand. now i use the mmgw for atmos. I would prefer the mgmc1. this is a L-room 7.5m (4m) x 8m. so many individual channels have to be tamed like a tiger😂. i only listen to music with a few mg 1.6. When I film look, then I light the rockets. the mmgw are not yet installed. today the 4 subs are discontinued.
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Post by ttocs on Feb 13, 2021 9:49:58 GMT -5
As David Letterman used to say, "Folks, this is not a competition, it's just an exhibition, please, no wagering."
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DYohn
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Post by DYohn on Feb 13, 2021 11:11:42 GMT -5
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Post by ttocs on Feb 13, 2021 11:50:38 GMT -5
I actually considered IB for a few days, but then I read that my wall construction isn't favorable to it. The wall plaster is about 1-1/4" thick and very rigid, basically concrete, and from what I read this IB is better with more flex. I was really interested in finding out which space would've been a better choice for IB, the stairwell going down to the basement at the back of my room, or the wall that extends up to the cathedral ceiling dividing the room from the attic? I will never know. With my current configuration I've got pretty much what I was after, and more dynamics than I expected.
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DYohn
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Post by DYohn on Feb 13, 2021 12:09:42 GMT -5
"the wall that extends up to the cathedral ceiling dividing the room from the attic" That would have been my target.
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Post by megash0n on Feb 13, 2021 12:41:47 GMT -5
I actually considered IB for a few days, but then I read that my wall construction isn't favorable to it. The wall plaster is about 1-1/4" thick and very rigid, basically concrete, and from what I read this IB is better with more flex. I was really interested in finding out which space would've been a better choice for IB, the stairwell going down to the basement at the back of my room, or the wall that extends up to the cathedral ceiling dividing the room from the attic? I will never know. With my current configuration I've got pretty much what I was after, and more dynamics than I expected. I can tell you from my own experience that it is near impossible to build a wall to withstand the force of the subs without unwanted noise from the vibrations. Now, of course it IS possible with insane construction. My wall in my theatre room is built with a sheet of osb on the back, two on the front... All of it glued and screwed to a well built 2*4 wall. Sheetrock on both sides of the wall. I have 2 pairs of 18 inch IB subs surface mounted to wall inserts made from a 2x4 frame, layers of osb and MDF. These rectangles if you will are then glued and screwed into place inside the wall. Then, the entire wall is braced with brackets and 2*4s to the concrete wall behind the front wall (air space). While they sound and feel incredible. The noise generated from the wall moving is almost unbearable at certain frequencies. Could it be improved? Probably. The point is that you can spend an enormous amount of time and money and still have vibration that is not ok. My recommendation would be to build manifolds that attach to your wall that contain your subs. Basically this is a subwoofer box big enough to house the subs. One side of the box is open. This opening points into your room. Think "port" if you like. The subs are installed in an opposing way to limit or remove the mechanical vibration and wall flex. You do lose a little spl, but for my room, the (4) 18s put out so much air pressure that I could watch the hair on my arm shift back and forth during low extension. They play so low and powerful that it seems like the house is about to come down, but you aren't hearing it. It's a true experience in my opinion. I'm not sure if there is anything to it or not, but I always tell people... It's like having the same level of audible sound but twice the air pressure. To me, in a room with normal subs, you can only go so high in pressure before they are too loud and unbalanced.
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Post by ttocs on Feb 13, 2021 12:46:27 GMT -5
I actually considered IB for a few days, but then I read that my wall construction isn't favorable to it. The wall plaster is about 1-1/4" thick and very rigid, basically concrete, and from what I read this IB is better with more flex. I was really interested in finding out which space would've been a better choice for IB, the stairwell going down to the basement at the back of my room, or the wall that extends up to the cathedral ceiling dividing the room from the attic? I will never know. With my current configuration I've got pretty much what I was after, and more dynamics than I expected. I can tell you from my own experience that it is near impossible to build a wall to withstand the force of the subs without unwanted noise from the vibrations. Now, of course it IS possible with insane construction. My wall in my theatre room is built with a sheet of osb on the back, two on the front... All of it glued and screwed to a well built 2*4 wall. Sheetrock on both sides of the wall. I have 2 pairs of 18 inch IB subs surface mounted to wall inserts made from a 2x4 frame, layers of osb and MDF. These rectangles if you will are then glued and screwed into place inside the wall. Then, the entire wall is braced with brackets and 2*4s to the concrete wall behind the front wall (air space). While they sound and feel incredible. The noise generated from the wall moving is almost unbearable at certain frequencies. Could it be improved? Probably. The point is that you can spend an enormous amount of time and money and still have vibration that is not ok. My recommendation would be to build manifolds that attach to your wall that contain your subs. Basically this is a subwoofer box big enough to house the subs. One side of the box is open. This opening points into your room. Think "port" if you like. The subs are installed in an opposing way to limit or remove the mechanical vibration and wall flex. You do lose a little spl, but for my room, the (4) 18s put out so much air pressure that I could watch the hair on my arm shift back and forth during low extension. They play so low and powerful that it seems like the house is about to come down, but you aren't hearing it. It's a true experience in my opinion. I'm not sure if there is anything to it or not, but I always tell people... It's like having the same level of audible sound but twice the air pressure. To me, in a room with normal subs, you can only go so high in pressure before they are too loud and unbalanced. I was under the impression from reading about it that IB "needs" some flex in a wall, and that a wall that is too rigid doesn't work as well. You're saying that the wall needs to be rigid, right?
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Post by ttocs on Feb 13, 2021 12:49:19 GMT -5
"the wall that extends up to the cathedral ceiling dividing the room from the attic" That would have been my target. That's kinda what I was thinking would be the case. The downside of using attic space, at least in my house, is that the attic is over all of the bedrooms which would limit usage when bedrooms are occupied during resting hours.
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DYohn
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Post by DYohn on Feb 13, 2021 12:50:19 GMT -5
I recommend not putting an IB in the wall, exactly for the reasons described above, but to build a separate baffle frame for them and mount with a vent into the HT room. Don't use the wall as part of the baffle. My 4 X AE 15" IB is bolted to the house joists in my attic space and vented into the HT room through the wall leading up to a skylight. No problems. Apply the correct EQ and I have big theater bass when I want it for a movie.
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DYohn
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Post by DYohn on Feb 13, 2021 12:51:22 GMT -5
"the wall that extends up to the cathedral ceiling dividing the room from the attic" That would have been my target. That's kinda what I was thinking would be the case. The downside of using attic space, at least in my house, is that the attic is over all of the bedrooms which would limit usage when bedrooms are occupied during resting hours. Yea that is the case in general when using a large architectural IB system. No one in the house gets to rest.
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Post by ttocs on Feb 13, 2021 12:54:01 GMT -5
This is something I've wondered about for a long time but cannot find any resource for an answer.
Can audible dynamics be measured? If so, what would be the method employed?
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DYohn
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Post by DYohn on Feb 13, 2021 13:03:04 GMT -5
This is something I've wondered about for a long time but cannot find any resource for an answer. Can audible dynamics be measured? If so, what would be the method employed? "Audible dynamics" as in changes in dbSPL due to loud vs. soft parts of a performance? Absolutely. Very simply measured using an RTA (real time analyzer) slightly more difficult to measure using an SPL meter.
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Post by ttocs on Feb 13, 2021 13:36:23 GMT -5
This is something I've wondered about for a long time but cannot find any resource for an answer. Can audible dynamics be measured? If so, what would be the method employed? "Audible dynamics" as in changes in dbSPL due to loud vs. soft parts of a performance? Absolutely. Very simply measured using an RTA (real time analyzer) slightly more difficult to measure using an SPL meter. In REW I can only see the one Peak from an event. I'd like to play a short duration of a music piece, select and compare one speaker setup with another playing the same section of music. Or is it better to play a single note, like a piano note for example? If I recorded audio using a DAW, would this be an acceptable way of comparing waveforms? The waveforms can be overlaid and compared very closely. I would think that this might show the rise time fairly clearly.
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DYohn
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Post by DYohn on Feb 13, 2021 13:47:27 GMT -5
REW is limited in what it can do - it's a glorified SPL meter. Yes, if you can record a track into a DAW you can measure the waveform peaks and calculate dynamic range. Some audio editing software will do this for you. Realize this is the dynamic range in the recording if you input the track directly. if it is a recorded measurement mic input, then it is the acoustic SPL in your room.
Here's the basic process using an SPL meter or DAW software: 1. Measure the ambient SPL in your room with nothing playing on the system. 2. Set this average ambient level as "zero," or if the software does not have this function, write it down. 3. Measure your track and note the peak. If you were able to set zero to ambient, then this is the total acoustic dbSPL in the recording as played through your system. If not, subtract your earlier written down ambient from this number. 4. If you are comparing one speaker to another, simply repeat the process for each one playing by itself, being sure not to touch the volume knob and using the same track.
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