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Post by p4t on Feb 7, 2021 14:18:30 GMT -5
Thank you for the diagram. Based on your diagram, then I set my front speakers as large, correct? And all four sub I have to time align it too, correct? Just make sure, I get this right. Yes! You optimize four subs to work all the LFE and only the bass below the capability of your fronts (40Hz? 50Hz?). Then all your small speakers get bass from your fronts down through their range, and the subs only do what the fronts can't do. But .... ttocs has another way to do it of course Thank you for your suggestion. I will give it a try. Also do you think dual mono setting any good? Dual mono + LFE, I meant.
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Post by ttocs on Feb 7, 2021 14:34:35 GMT -5
Mine is esl, go down to 42hz. Sorry I wrote wrong before. My plan is using the KEF subs for dedicated sub for front left and front right. And pair of JL sub for LFE. The problems is, right now I have only 1 minidsp already use 1 input for JL sub. And the other problem is I cannot put my KEF sub anywhere near the front speakers, cause very bad freq response if I put the sub there. And about the KEF KC62, I think is good considering for the size. Based on my testing in my room, can go flat FR to 40Hz and below 40hz have dips and peaks (room interactions) but I think the sub will easily go to 20hz flat in anechoic testing. Too bad you've only got the one input available on the miniDSP. hmmmm . . . . It is my opinion that using the Speaker Level connections of the subwoofer is best when the sub can be next to the speaker it's connected to. When I did this, there was improvement with each additional subwoofer I added to the Main speaker. I experimented with up to 3 subwoofers, and after adding the third subwoofer it really smoothed out the response even before using any calibration software, and no PEQ was used. So improvements "can" be made adding a sub to a "poor" location that the Main speaker must use. But, to get these improvements and adjustable phase control is needed. The magic 3 ingredients are Volume/Gain, Low Pass Filter LPF, and Phase/Delay. You don't get very far with one subwoofer. Two subs will do a lot! Three subs is the icing on the cake, not as much improvement realized but definitely the way to go if not budget restricted. Let me think a bit about what else to consider . . . . .
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Post by leonski on Feb 7, 2021 15:19:09 GMT -5
My first question is what are trying to accomplish? You seem focussed on max dbSPL, which is not the correct thing to focus on unless you are a car audio competition builder. So what are you looking for in your room? Bingo!
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Post by monkumonku on Feb 7, 2021 15:21:09 GMT -5
Hi Marcl and Ttocs. I have questions. I have Martin logan esl specs can go down to 55hz -3db. Right now, the sub location is 1 on center front wall and 1 on center back wall (both are JL 12” sub). I just bought a pair of new sub (KEF KC62) and I want do what like ttocs did, pair each sub to the front speakers to make the fronts full range. But I just found out the FR of the sub is very bad if the put it near the front speakers (-15 to -20db around 40-50db) the best location I found for the new sub is right on the rear corner left and right of the 3 seater sofa. I have minidsp 2x4 non HD, that curently use input 1 for align the 2 JL sub. And I want to separate the LFE to JL sub, and the rest to KEF. I tested the KEF sub is good to around 30Hz. What do you guys suggest how should I connect the KEF sub? Oh by the way I still have a yamaha SW300 10” ported sub I am not using, may if I can make this to dedicated center channel sub? Any suggestion? Thank you. Sorry to go off track a bit, but you are in possession of the KEF KC62 subs? I thought they were still on preorder status, at least in the U.S. With published specs going down to 11hz -3db, it sounds like what you have measured with them is way off of that mark and not in a good way. 30hz is decent, especially for such a small sub, but nowhere near 11hz.
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Post by leonski on Feb 7, 2021 15:24:20 GMT -5
My first question is what are trying to accomplish? You seem focussed on max dbSPL, which is not the correct thing to focus on unless you are a car audio competition builder. So what are you looking for in your room? The max SPL stuff is just baseline testing. I wanted to know. I also want to test the max output of each layout to see at what point the output is lower, and that point happened last night when I tested an arrangement and lost 2dB and lots of headroom forcing REW to stop due to clipping. What am I looking for? Knowledge. I want to find out what happens: When I combine two subs together. When I combine three subs together. When one or more subs is located in any of the spots that I may want to choose to put one, or two, or three subs. Based on results, I may want to add more subs, only use two subs, whatever. I'm open to discovery. I may end up with an entire wall of subwoofers a'la Van Halen with his wall of 412 cabs! Actually I don't, I've already seen the charts that show subwoofer combos and the radiated patterns when stacked or all at the ground plane, separated, etc, and it pays to have some idea of what arrangement can cause nulls in the middle. It's easier than I thought to create a null at the MLP simply by arranging two sub sources (singles or multiples) at the wrong distance apart from each other. What's most interesting about combining subs is being careful about the arrangement. For example, when subs are stacked, the radiation pattern is wider than it is tall; and when the subs are next to each other the pattern is taller than it is wide. From Electro-Voice: " The basic directivity rule applies independently in the horizontal and vertical planes. For example, a horizontal line of subwoofers might be large horizontally and small vertically. Therefore, its directivity would be narrow horizontally and wide vertically". So if you want to have wide (horizontally) dispersion then it is better to array subwoofers in a stacked formation, or tall. I have tested stacking my 3 subs with good results, but it would be better - I suspect - to have a pair of matching stacks. But the results were good enough to perform more tests, although, when doing maximum output tests I'll need to secure the subs on top better, the top one started "walking" to the edge of the cliff and I was barely able to stop disaster. So far, I'm not too old to learn new tricks. You're a pretty smart cookie and best of all? Curious. IMO? Read the Harman article on multiple sub woofers. That may help fill in some blanks and allow you to ask better questions going forward. They did MUCH of what you are now doing and made a very systematic study of the issue. I'd be surprised if parts of the article didn't make you smile and maybe others make you go 'back to the drawing board'....and experiment further. Nothing but To The Good.. Just for example? My HSU sub will rattle stuff nearly off the walls. But when playing VERY LF? Output is very limited and distorts if turned UP too much. But that's just 'by ear' with no measurements or any of those nice charts and graphs...
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Post by leonski on Feb 7, 2021 15:26:53 GMT -5
There have been a couple questions about my post regarding the behavior of the LFE channel. Here are the measurements that I did using the REW Output #4. I tested with Equalization set to User and no filters loaded. No equalization - neither Dirac nor PEQ. I used only the Center Subwoofer output. The Center Subwoofer output connects to a miniDSP which drives two subwoofers placed front and rear of the room. No filtering or crossovers in the miniDSP; only a delay on the rear sub to align it to the front sub. I set out to verify a few things: Is there a difference in the LFE response with the Crossover Slope set to 12 or 24db/octave? (Yes) Is there a difference in the LFE response with the processor Mode set to Surround or Direct? (No) Is there a difference in the LFE response with the Center Sub set to LFE or Mono? (No)Here's a screen shot of all the results from REW. I had a question about the crossover frequency, since the Dolby spec says LFE goes up to 120Hz. That is the spec, but look at the graph ... for practical purposes it rolls off at 100Hz. Note also that the low-pass at 100Hz is happening in the processor. I have no reason to believe REW or JRiver Media Center are applying that low-pass. View AttachmentI noticed something else interesting, the consequences of which (if any) are debatable. Take a look at the Impulse Response plots for all the test results. View AttachmentRemember that measurements in Direct Mode are in blue, Surround Mode in pink. As you can see, in Surround Mode the signal is delayed 3ms. And for both Modes, the 24 db/octave Crossover Slope is delayed 3ms vs the 12 db/octave Slope. The Phase plot also showed phase shift varying with frequency that corresponded to the delays. I don't think the delay of Surround vs Direct is of any consequence since presumable all channels move together. Part of the additional delay may be ascribed to the fact that Each 6db of crossover slope is progressively 90 degrees later than the last. At some point and with the very long wavelengths with which you are concerned, it starts to 'Add Up'......
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Post by p4t on Feb 7, 2021 21:12:41 GMT -5
Hi Marcl and Ttocs. I have questions. I have Martin logan esl specs can go down to 55hz -3db. Right now, the sub location is 1 on center front wall and 1 on center back wall (both are JL 12” sub). I just bought a pair of new sub (KEF KC62) and I want do what like ttocs did, pair each sub to the front speakers to make the fronts full range. But I just found out the FR of the sub is very bad if the put it near the front speakers (-15 to -20db around 40-50db) the best location I found for the new sub is right on the rear corner left and right of the 3 seater sofa. I have minidsp 2x4 non HD, that curently use input 1 for align the 2 JL sub. And I want to separate the LFE to JL sub, and the rest to KEF. I tested the KEF sub is good to around 30Hz. What do you guys suggest how should I connect the KEF sub? Oh by the way I still have a yamaha SW300 10” ported sub I am not using, may if I can make this to dedicated center channel sub? Any suggestion? Thank you. Sorry to go off track a bit, but you are in possession of the KEF KC62 subs? I thought they were still on preorder status, at least in the U.S. With published specs going down to 11hz -3db, it sounds like what you have measured with them is way off of that mark and not in a good way. 30hz is decent, especially for such a small sub, but nowhere near 11hz. Yes, I have a pair of KEF KC62. I live in Indonesia, and these subs have been available since 2 or 3 weeks ago. About my measurement, yes maybe a way off, since I cannot test it outdoor when no building around. But in my opinion it is very descent sub for the size. Of course if anyone have the space, I think will better off with bigger sub such as SVS SB3000, which is still very compact size in my opinion.
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Post by p4t on Feb 7, 2021 21:23:45 GMT -5
Mine is esl, go down to 42hz. Sorry I wrote wrong before. My plan is using the KEF subs for dedicated sub for front left and front right. And pair of JL sub for LFE. The problems is, right now I have only 1 minidsp already use 1 input for JL sub. And the other problem is I cannot put my KEF sub anywhere near the front speakers, cause very bad freq response if I put the sub there. And about the KEF KC62, I think is good considering for the size. Based on my testing in my room, can go flat FR to 40Hz and below 40hz have dips and peaks (room interactions) but I think the sub will easily go to 20hz flat in anechoic testing. Too bad you've only got the one input available on the miniDSP. hmmmm . . . . It is my opinion that using the Speaker Level connections of the subwoofer is best when the sub can be next to the speaker it's connected to. When I did this, there was improvement with each additional subwoofer I added to the Main speaker. I experimented with up to 3 subwoofers, and after adding the third subwoofer it really smoothed out the response even before using any calibration software, and no PEQ was used. So improvements "can" be made adding a sub to a "poor" location that the Main speaker must use. But, to get these improvements and adjustable phase control is needed. The magic 3 ingredients are Volume/Gain, Low Pass Filter LPF, and Phase/Delay. You don't get very far with one subwoofer. Two subs will do a lot! Three subs is the icing on the cake, not as much improvement realized but definitely the way to go if not budget restricted. Let me think a bit about what else to consider . . . . . Yes, unfortunately, right now I have only 1 minidsp and only 1 input left empty. By the way just curious for your setup, for the fronts why your connection using high level in and minidsp? Why not using directly from xmc-2 front left out to input 1 minidsp than output 1 to front left speaker and output 2 to front left speaker subwoofer. Do the same for front right for input 2. By doing this you can adjust the crossover etc for smooth FR from the sub to the speakers. Maybe, I am missing something here.
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Post by ttocs on Feb 8, 2021 2:52:30 GMT -5
By the way just curious for your setup, for the fronts why your connection using high level in and minidsp? Why not using directly from xmc-2 front left out to input 1 minidsp than output 1 to front left speaker and output 2 to front left speaker subwoofer. Do the same for front right for input 2. By doing this you can adjust the crossover etc for smooth FR from the sub to the speakers. Maybe, I am missing something here. The simple answer is I prefer to listen to music in Reference Stereo. Additionally . . . The Speaker Level connection is so much more flexible in how I tune the subwoofers to each Front speaker. Setting up the Fronts as Small rolls off the bass below the crossover setting. Keeping them as Large allows me to use the bass control to reduce the bass by as much as -10dB but the bass still extends below 20Hz, so it's 20Hz -10dB, and 100Hz -2.5dB, and 200Hz @0db. Reference Stereo remains my preferred audio mode for music and Large Fronts make this happen. Here's a couple graphics to show how I'm using the Fronts and the 5 subwoofers. This first one shows each Front with its pair of subs connected via speaker connections. The bottom sub of each Front and the sub at the back of the room are for LFE and controlled by the miniDSP and connected to the LFE inputs on each sub. Since the Center Sub is setup for LFE, the bass for Small speakers is directed to the Large Fronts. The one issue I've been lazy about fixing is a big dip from 60-70Hz when both Fronts play mono bass, and I'm pretty sure this can be helped by using the sub at the back of the room controlled by a second miniDSP fed by the Left/Right split outputs from the processor and connected to the Line input. This still circumvents the bass management in the processor so it would still allow Reference Stereo to be used. People keep asking why I don't use BM for the Fronts. I've tried it many times and keep going back to running them as Large. When I had ML Vista speakers that went down to 43Hz, different story. The crossover setup that worked best for those was 50Hz. The way the system is currently running, bass is just as easy to produce as any other range of frequencies. It's full, precise, dynamic, and definitely not bloated. I've been trying different settings for Dirac Curtains to cutoff the upper frequencies to try and find a setting that doesn't stifle the upper ranges so it sounds as free as not using Dirac while listening to music. Too early to tell yet what I think of it. I started listening tonight with a Dirac filter that wasn't Curtain limited and it sounded squashed, so I listened to the last couple albums in Reference Stereo with the final album being Dark Side Of The Moon. That heartbeat never sounded better!
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Post by p4t on Feb 8, 2021 13:37:56 GMT -5
By the way just curious for your setup, for the fronts why your connection using high level in and minidsp? Why not using directly from xmc-2 front left out to input 1 minidsp than output 1 to front left speaker and output 2 to front left speaker subwoofer. Do the same for front right for input 2. By doing this you can adjust the crossover etc for smooth FR from the sub to the speakers. Maybe, I am missing something here. The simple answer is I prefer to listen to music in Reference Stereo. Additionally . . . The Speaker Level connection is so much more flexible in how I tune the subwoofers to each Front speaker. Setting up the Fronts as Small rolls off the bass below the crossover setting. Keeping them as Large allows me to use the bass control to reduce the bass by as much as -10dB but the bass still extends below 20Hz, so it's 20Hz -10dB, and 100Hz -2.5dB, and 200Hz @0db. Reference Stereo remains my preferred audio mode for music and Large Fronts make this happen. View AttachmentHere's a couple graphics to show how I'm using the Fronts and the 5 subwoofers. This first one shows each Front with its pair of subs connected via speaker connections. View Attachment The bottom sub of each Front and the sub at the back of the room are for LFE and controlled by the miniDSP and connected to the LFE inputs on each sub. View AttachmentSince the Center Sub is setup for LFE, the bass for Small speakers is directed to the Large Fronts. The one issue I've been lazy about fixing is a big dip from 60-70Hz when both Fronts play mono bass, and I'm pretty sure this can be helped by using the sub at the back of the room controlled by a second miniDSP fed by the Left/Right split outputs from the processor and connected to the Line input. This still circumvents the bass management in the processor so it would still allow Reference Stereo to be used. People keep asking why I don't use BM for the Fronts. I've tried it many times and keep going back to running them as Large. When I had ML Vista speakers that went down to 43Hz, different story. The crossover setup that worked best for those was 50Hz. The way the system is currently running, bass is just as easy to produce as any other range of frequencies. It's full, precise, dynamic, and definitely not bloated. I've been trying different settings for Dirac Curtains to cutoff the upper frequencies to try and find a setting that doesn't stifle the upper ranges so it sounds as free as not using Dirac while listening to music. Too early to tell yet what I think of it. I started listening tonight with a Dirac filter that wasn't Curtain limited and it sounded squashed, so I listened to the last couple albums in Reference Stereo with the final album being Dark Side Of The Moon. That heartbeat never sounded better! Now , I understand why you are running high level in. In my case, with what I have now, I think I will try to take signal from front left and front right to 1 rca cable then take right sub mono out to rca, and combine both rca to input 2 on minidsp and output to both kef sub Then I just need to figure it out for crossover setting. Do you think this will work?
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Post by ttocs on Feb 8, 2021 15:59:22 GMT -5
Now , I understand why you are running high level in. In my case, with what I have now, I think I will try to take signal from front left and front right to 1 rca cable then take right sub mono out to rca, and combine both rca to input 2 on minidsp and output to both kef sub Then I just need to figure it out for crossover setting. Do you think this will work? Your situation got me to thinking about a different wiring strategy for my setup and incorporating the rear sub into being used for L&R smoothing. RDL makes some nice quality converters, combiners, and mixers. All very versatile stuff. I used a couple of their Balanced to Unbalanced transformer converters when my equipment was over 20 feet away from my tube amps, and they worked very well, and best of all - no hum - due to the use of a transformer design. I just called RDL to ask which product is best for this type of combining and they recommend the STICK-ON® SERIES Model ST-MX3 Line Level Mixer. It will take multiple balanced inputs and combine them to a mono balanced or unbalanced output. It's an active device so it needs power. Quoting from their info: "The ST-MX3 is a three-channel audio mixer for combining line-level signals to a line-level output. Individual level control is provided for each input. Each input features a separate preamplifier circuit, which isolates it from the other inputs. A single-turn trimmer is provided for each of the three input preamps. Signals from the three preamps are actively summed and fed to the output line-level driver amplifier. The line-input circuit design of the ST-MX3 allows the inputs to accept either balanced to unbalanced signals, or either high or low impedance. The output is capable of driving into either high or low impedance, balanced or unbalanced loads." This looks like it might be good for me as well for summing the L&R outputs into the second input on the miniDSP and combining to the signal that's already going to the sub at the back of the room via wireless. This company is located in Florida and has a good price. Herman ProAV
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Post by p4t on Feb 8, 2021 21:06:48 GMT -5
Now , I understand why you are running high level in. In my case, with what I have now, I think I will try to take signal from front left and front right to 1 rca cable then take right sub mono out to rca, and combine both rca to input 2 on minidsp and output to both kef sub Then I just need to figure it out for crossover setting. Do you think this will work? Your situation got me to thinking about a different wiring strategy for my setup and incorporating the rear sub into being used for L&R smoothing. RDL makes some nice quality converters, combiners, and mixers. All very versatile stuff. I used a couple of their Balanced to Unbalanced transformer converters when my equipment was over 20 feet away from my tube amps, and they worked very well, and best of all - no hum - due to the use of a transformer design. I just called RDL to ask which product is best for this type of combining and they recommend the STICK-ON® SERIES Model ST-MX3 Line Level Mixer. It will take multiple balanced inputs and combine them to a mono balanced or unbalanced output. It's an active device so it needs power. Quoting from their info: "The ST-MX3 is a three-channel audio mixer for combining line-level signals to a line-level output. Individual level control is provided for each input. Each input features a separate preamplifier circuit, which isolates it from the other inputs. A single-turn trimmer is provided for each of the three input preamps. Signals from the three preamps are actively summed and fed to the output line-level driver amplifier. The line-input circuit design of the ST-MX3 allows the inputs to accept either balanced to unbalanced signals, or either high or low impedance. The output is capable of driving into either high or low impedance, balanced or unbalanced loads." This looks like it might be good for me as well for summing the L&R outputs into the second input on the miniDSP and combining to the signal that's already going to the sub at the back of the room via wireless. This company is located in Florida and has a good price. Herman ProAVThanks for the info on Herman ProAv. For your setup right now you L1,R1 and LFE 5 works also as LFE, right. I have suggestion also make L2,R2 and LFE as another group, to smooth out the bass response for the fronts.
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Post by ttocs on Feb 8, 2021 21:48:48 GMT -5
Thanks for the info on Herman ProAv. For your setup right now you L1,R1 and LFE 5 works also as LFE, right. I have suggestion also make L2,R2 and LFE as another group, to smooth out the bass response for the fronts. The Left speaker, L1, and L2 are all one channel - the Left Channel. So the Left Front Channel is produced by the Martin Logan 13A, and both 1100X subwoofers, they operate as one. I call it the Left Group. The same is true for the Right Group. Put another way, those subwoofers "are" the Fronts, along with the 13A's. I don't have enough woofers . . . . . So when mono bass is produced by the Left Group and the Right Group that dip between 60-70Hz shows up. And, just like adding the rear sub for the LFE Group smoothed out that same dip, the same will be true when I add that same sub to the Left and Right Groups. I just haven't made the cables yet. I already have a second miniDSP, but now I'm considering getting that Line Level Mixer. I'll use the miniDSP-2 first since I've already got it and that's what I got it for. It's just that the mixer is a bit easier to implement IMO. The most dramatic difference from using "just" the 13A speakers vs the 13A's plus two subs each is the dynamic impact of the bass. I don't like the terms "fast" or "slow" when describing subwoofers, but, after adding a SOS (Stack Of Subs) to each Front speaker I really can't avoid using a similar word - quick. The bass is quicker. And because it's spread out over more drivers I don't hear excess "boom" which would be a reduction in clean dynamic bass yet more overall bass, no, instead it's a more "accurate" sounding amount of bass with more impact. The dual self-powered woofers in each 13A work less hard, and each sub works less hard, so they all work better together. Keep in mind that all the woofers have their own amps, so it's only the electrostatic panels that are powered by external amps. So it was never about reducing the workload of any external amps, it was always about better bass, and as it turns out - a wider soundstage! So what Rel says about a wider soundstage is accurate when they tout their "Subwoofer Line Arrays". If I ever start working full time again I'd like to get two more subs for stacks of 3. When I tested a 3-stack it was a better outcome. But I think I'll be working on room treatment for a while first.
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Post by ttocs on Feb 8, 2021 23:35:12 GMT -5
I don't know why I didn't think about this simplified version before today, simply connecting the two miniDSP's. So the output of miniDSP2 will go to miniDSP1-Input2 and then Route to LFE5. The wireless is already in place, so why not use it? duh! No difference in cabling really, except at the sub, and a fourth VSUB pair is not needed. This will use LFE5 at the back of the room to smooth and reduce the dip from 60-70Hz when the Left Group and Right Group are both playing the same mono bass signal. This will affect stereo music as well as BM.
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Post by marcl on Feb 9, 2021 6:12:51 GMT -5
Now , I understand why you are running high level in. In my case, with what I have now, I think I will try to take signal from front left and front right to 1 rca cable then take right sub mono out to rca, and combine both rca to input 2 on minidsp and output to both kef sub Then I just need to figure it out for crossover setting. Do you think this will work? Your situation got me to thinking about a different wiring strategy for my setup and incorporating the rear sub into being used for L&R smoothing. RDL makes some nice quality converters, combiners, and mixers. All very versatile stuff. I used a couple of their Balanced to Unbalanced transformer converters when my equipment was over 20 feet away from my tube amps, and they worked very well, and best of all - no hum - due to the use of a transformer design. I just called RDL to ask which product is best for this type of combining and they recommend the STICK-ON® SERIES Model ST-MX3 Line Level Mixer. It will take multiple balanced inputs and combine them to a mono balanced or unbalanced output. It's an active device so it needs power. Quoting from their info: "The ST-MX3 is a three-channel audio mixer for combining line-level signals to a line-level output. Individual level control is provided for each input. Each input features a separate preamplifier circuit, which isolates it from the other inputs. A single-turn trimmer is provided for each of the three input preamps. Signals from the three preamps are actively summed and fed to the output line-level driver amplifier. The line-input circuit design of the ST-MX3 allows the inputs to accept either balanced to unbalanced signals, or either high or low impedance. The output is capable of driving into either high or low impedance, balanced or unbalanced loads." This looks like it might be good for me as well for summing the L&R outputs into the second input on the miniDSP and combining to the signal that's already going to the sub at the back of the room via wireless. This company is located in Florida and has a good price. Herman ProAVThis is pretty interesting! I used passive XLR splitters and combiners, but this has the advantage of level controls too. Found the data sheet which explains wiring. 2364908.pdf (834.48 KB)
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Post by ttocs on Feb 9, 2021 9:31:13 GMT -5
Your situation got me to thinking about a different wiring strategy for my setup and incorporating the rear sub into being used for L&R smoothing. RDL makes some nice quality converters, combiners, and mixers. All very versatile stuff. I used a couple of their Balanced to Unbalanced transformer converters when my equipment was over 20 feet away from my tube amps, and they worked very well, and best of all - no hum - due to the use of a transformer design. I just called RDL to ask which product is best for this type of combining and they recommend the STICK-ON® SERIES Model ST-MX3 Line Level Mixer. It will take multiple balanced inputs and combine them to a mono balanced or unbalanced output. It's an active device so it needs power. Quoting from their info: "The ST-MX3 is a three-channel audio mixer for combining line-level signals to a line-level output. Individual level control is provided for each input. Each input features a separate preamplifier circuit, which isolates it from the other inputs. A single-turn trimmer is provided for each of the three input preamps. Signals from the three preamps are actively summed and fed to the output line-level driver amplifier. The line-input circuit design of the ST-MX3 allows the inputs to accept either balanced to unbalanced signals, or either high or low impedance. The output is capable of driving into either high or low impedance, balanced or unbalanced loads." This looks like it might be good for me as well for summing the L&R outputs into the second input on the miniDSP and combining to the signal that's already going to the sub at the back of the room via wireless. This company is located in Florida and has a good price. Herman ProAVThis is pretty interesting! I used passive XLR splitters and combiners, but this has the advantage of level controls too. Found the data sheet which explains wiring. When I called, I was asking about a passive product but the tech I spoke with strongly suggested not using that. He said it was better than "just twisting wires together", but would not be anywhere near as good as what this mixer would be capable of. Plus, he said there would be no concern with impedance or mixing Balanced/UnBalanced signals.
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Post by p4t on Feb 9, 2021 11:22:32 GMT -5
Thanks for the info on Herman ProAv. For your setup right now you L1,R1 and LFE 5 works also as LFE, right. I have suggestion also make L2,R2 and LFE as another group, to smooth out the bass response for the fronts. The Left speaker, L1, and L2 are all one channel - the Left Channel. So the Left Front Channel is produced by the Martin Logan 13A, and both 1100X subwoofers, they operate as one. I call it the Left Group. The same is true for the Right Group. Put another way, those subwoofers "are" the Fronts, along with the 13A's. I don't have enough woofers . . . . . So when mono bass is produced by the Left Group and the Right Group that dip between 60-70Hz shows up. And, just like adding the rear sub for the LFE Group smoothed out that same dip, the same will be true when I add that same sub to the Left and Right Groups. I just haven't made the cables yet. I already have a second miniDSP, but now I'm considering getting that Line Level Mixer. I'll use the miniDSP-2 first since I've already got it and that's what I got it for. It's just that the mixer is a bit easier to implement IMO. The most dramatic difference from using "just" the 13A speakers vs the 13A's plus two subs each is the dynamic impact of the bass. I don't like the terms "fast" or "slow" when describing subwoofers, but, after adding a SOS (Stack Of Subs) to each Front speaker I really can't avoid using a similar word - quick. The bass is quicker. And because it's spread out over more drivers I don't hear excess "boom" which would be a reduction in clean dynamic bass yet more overall bass, no, instead it's a more "accurate" sounding amount of bass with more impact. The dual self-powered woofers in each 13A work less hard, and each sub works less hard, so they all work better together. Keep in mind that all the woofers have their own amps, so it's only the electrostatic panels that are powered by external amps. So it was never about reducing the workload of any external amps, it was always about better bass, and as it turns out - a wider soundstage! So what Rel says about a wider soundstage is accurate when they tout their "Subwoofer Line Arrays". If I ever start working full time again I'd like to get two more subs for stacks of 3. When I tested a 3-stack it was a better outcome. But I think I'll be working on room treatment for a while first. Yes, I agree with you about accurate bass. I am also on quest for accurate bass. Have to do some experiment with the sub. Just wondering, if I make the front as large by adding dedicated sub for each of the front speaker but the sub location on the back, can dirac manage this situation especially the timing between sub and the front.
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Post by ttocs on Feb 9, 2021 11:27:29 GMT -5
I might have a problem no matter which direction I go with regard to using either the miniDSP2 or the RDL ST-MX3, too much delay. I don't want to run the L&R Speaker Groups through an extra device, I'd like to keep the signal as pure as I can. But the split signal going to the rear LFE5 and it is farther away by a few feet and will be delayed just for that reason alone. Not sure it's worth the trouble at this point, but I'll give it a go anyway. This would be the wiring scheme for adding the rear sub into the mix for Left and Right channel 60-70Hz dip fix. The Y-cables would have Pin-2/Shield going to the M-125 amps, and Pin-3/Shield going to miniDSP2 inputs for combining into Mono that then goes to the second input of miniDSP1. Attachment Deletededit: Maybe the delay won't be so bad, it's only 1'-2" farther away than the fronts. Can I hear 1 millisecond delay of a 65Hz sound? (For anyone who doesn't know me, that's a joke.)
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Post by ttocs on Feb 9, 2021 11:32:27 GMT -5
Yes, I agree with you about accurate bass. I am also on quest for accurate bass. Have to do some experiment with the sub. Just wondering, if I make the front as large by adding dedicated sub for each of the front speaker but the sub location on the back, can dirac manage this situation especially the timing between sub and the front. If connecting as I've done, without using a Subwoofer Output for the Left/Right Main Speakers, you would need to time align each sub to each Front speaker before running Dirac. Dirac will only see discrete outputs and doesn't "see" how many drivers are connected to any individual output. In my case Dirac only sees the Left Channel, and doesn't know that I've got a speaker and two subwoofers connected to it. It's just "one big speaker" as far as Dirac knows.
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Post by p4t on Feb 9, 2021 21:21:00 GMT -5
Yes, I agree with you about accurate bass. I am also on quest for accurate bass. Have to do some experiment with the sub. Just wondering, if I make the front as large by adding dedicated sub for each of the front speaker but the sub location on the back, can dirac manage this situation especially the timing between sub and the front. If connecting as I've done, without using a Subwoofer Output for the Left/Right Main Speakers, you would need to time align each sub to each Front speaker before running Dirac. Dirac will only see discrete outputs and doesn't "see" how many drivers are connected to any individual output. In my case Dirac only sees the Left Channel, and doesn't know that I've got a speaker and two subwoofers connected to it. It's just "one big speaker" as far as Dirac knows. I see. So I have to use minidsp then, no choice.
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