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#1 ·
So I decided to buy it and I have it on my desk. I bought the one that came assembled but I realize it does not come with power. I did ask for the DC power option, which is just a terminal block (5 to 12VDC), Can I just take one of the 100 old 12V plugs I have lying around???




Its this one
http://www.minidsp.com/images/docume...02x4%20Box.pdf


Now, I know its powered over USB but I didnt think i needed a PC with it at all times.


Damn slick little box though if I can get this working even close to the DCX Im going to be very happy!!



UPDATE : Here are some links to cables or how to make a cable for the balanced minidsp.

http://www.hometheatershack.com/foru...dsp-howto.html
 
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#4,141 ·
Each sub should not be independently corrected unless a subwoofer optimization algorithm (MSO, SMF) is being used. Since you'll always be listening to the interaction of the subs, you should correct the interaction of the subs. Fire all of them up with the same signal and measure their interaction. Waste of resources to correct (electronically) peaks & dips on any of the subs when other subs might be doing that already (acoustically).
 
#4,142 ·
I have a 2x4HD for my two IB subwoofer manifolds to limit them. I am planning to add 3 more sealed subs in the room to increase midbass. I would like to run these along with my LCR through the miniDSP. I’m can get by with two 2x4HDs providing 8 outputs and 4 inputs. My question is would going to a rack mountable 10x10 provide any advantages besides easier to adjust all EQ by connecting to one device and that it can sit in my rack and be pretty? I’m not currently balanced, but may go to separates down the road for balanced connects so I know that would be a plus on the 10x10. Does the processing on the 10x10 handle lower single Hz filters any better? Is there the same amount of delay adjustments available? I’m feeling too lazy to search for details right now and it would be easy to just buy another 2x4HD so I’ll throw this out there.


Sent from my iPhone using Tapatalk
 
#4,143 ·
So here is my setup question. I have two FTW-21" subs in sealed enclosures that flank my center channel, just inside of my mains. Amp is an Fp10000q clone 4chn. Receiver has dual sub outputs. I have a 2x4 balanced.
My plan is to add two 18"s in sealed enclosures behind my couch in the rear. My thought is to run the front subs off one output of the receiver and the rear subs off the other. They would feed each of the two inputs on the 2x4. Then would use each of the four outputs on the 2x4 to feed each channel of the amp. Is this the correct setup? Or should I just use one input on the 2x4? I already have the usb mic from mini dsp, as well as have REW downloaded to my laptop. 100% clueless on how to use either the dsp or the REW program so will be struggling through this learning curve. Reading above about tuning all subs together rather than by themselves, has me unsure how I should do this. Especially since I am yet to fire up the 2x4 to even see the menus. Any advice to get me going? Photo shows my front stage. Yes, I run the four towers up front. My receiver has a front wide or front high setup so I roll with front wide and love it. Will keep this setup until I buy a house where I can go Atmos.


 
#4,145 ·
So here is my setup question. I have two FTW-21" subs in sealed enclosures that flank my center channel, just inside of my mains. Amp is an Fp10000q clone 4chn. Receiver has dual sub outputs. I have a 2x4 balanced.
My plan is to add two 18"s in sealed enclosures behind my couch in the rear. My thought is to run the front subs off one output of the receiver and the rear subs off the other. They would feed each of the two inputs on the 2x4. Then would use each of the four outputs on the 2x4 to feed each channel of the amp. Is this the correct setup? Or should I just use one input on the 2x4? I already have the usb mic from mini dsp, as well as have REW downloaded to my laptop. 100% clueless on how to use either the dsp or the REW program so will be struggling through this learning curve. Reading above about tuning all subs together rather than by themselves, has me unsure how I should do this. Especially since I am yet to fire up the 2x4 to even see the menus. Any advice to get me going? Photo shows my front stage. Yes, I run the four towers up front. My receiver has a front wide or front high setup so I roll with front wide and love it. Will keep this setup until I buy a house where I can go Atmos.


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Several comments. In a multi-sub setup, the 2x4 typically provides several functions. First, it allows individual delays on each of the output channels to time-align the subs. Second, it allows for PEQ correction to flatten out sub response. And finally, it allows the signals from multiple subs to be consolidated onto one, or two, input channels from the AVR. I see you have an Onkyo AVR. I am not familiar with the capabilities of your model, so I don’t know how it treats the two sub outputs. If it is one of the older models with Audyssey XT32, then it is time-aligning and equalizing the sub signals on each output independently. If the AVR is treating both outputs as the same signal, then that is a different situation.

My first question is, will the two rear subs be equidistant from the MLP? It looks like the front two subs are equidistant. If both sub pairs are equidistant, and the AVR time-aligns the two sub outputs independently, then you don’t need to worry about using the 2x4 to time-align the subs, and you should hook the two front subs to one output, and the two rear subs to the other output. If the AVR doesn’t handle the two outputs independently, then use only one sub output from the AVR, and follow the 2x4 guideline in my sig WRT how to time-align the fours subs using the 2x4 delay settings.

And WRT adding PEQ in the 2x4 to smooth the sub channel response, measure the combined four-sub signal using REW, and use the combined response as input to REW’s EQ Tool to create the PEQ filters that are then exported and loaded into the 2x4 on the input channel. Do not EQ each sub separately—use the combined sub signal. How to use the REW EQ Tool is also described in the 2x4 guide in my sig.
 
#4,146 ·
I would also add that the tight placement of the speakers and subs across the front walls does not allow any flexibility in speaker or sub placement. Placement is the single most important factor in the quality of audio response in the room. Placement of the mains determines imaging and sound stage. Placement of the subs determines how well room modes are handled, and is crucial in providing quality bass output. It may be that the placements you have are “perfect”—only REW measurements will tell. However, if the response is not optimal, moving things around will be difficult with the way things are organized.
 
#4,147 ·
Jerry,

Just to clarify one point in your post; AVRs with dual discrete sub outputs do not EQ each output independently, they only set separate delay and trim. Both outputs are EQ'ed as one.

I have an AVR with Audyssey XT32 and SubEQ HT (discrete dual sub outputs) and have found there is nothing to gain by using both outputs into the MiniDSP. You can do everything you need with a single sub out to the MiniDSP (if you are using REW, of course).
 
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#4,155 ·
I have a question about mic placement (that I can’t seem to find an answer to).
I have one of those cross spectrum labs mics that comes with cal files for 0, 90, etc degree placements.
If I am doing close to driver measurements for crossover selection and such, should I be pointing the mic directly at the driver and using the 0 degree cal file?
And if I am measuring room response, do I point the mic straight up and use the 90 degree file?
 
#4,158 ·
After reading the first two pages of this thread, I come up with nothing that I want to know. Men beating their chests while bickering. I am interested in the ability to time align, and equalize each of my subs if possible, and how to do so if it is capable. I have 4 subs. 3 stacked in front left of room. 2 brands up front. My rear size is different from the fronts. You can see my thread in “What’s your system configuration” section. Maybe the answers I seek are here buried in the 139 pages, but I don’t have any interest in haveing to find it among all the pages. So my question: will it do the aforementioned teaks I seek?
 
#4,160 ·
LOL! :D


After reading the first two pages of this thread, I come up with nothing that I want to know. Men beating their chests while bickering. I am interested in the ability to time align, and equalize each of my subs if possible, and how to do so if it is capable. I have 4 subs. 3 stacked in front left of room. 2 brands up front. My rear size is different from the fronts. You can see my thread in “What’s your system configuration” section. Maybe the answers I seek are here buried in the 139 pages, but I don’t have any interest in haveing to find it among all the pages. So my question: will it do the aforementioned teaks I seek?
Instead of reading the entire thread, just take a look at the MiniDSP and REW links in AustinJerry's sig and all your questions will be answered.

Reading (or at least skimming) the entire thread is still not a bad idea....
 
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#4,161 ·
Sorry for the delayed reply. Had to go into work for a few hours. I will try to answer the above questions.
1) Receiver has XT32. But I do not use it. Have tried the calibration twice and did not like how my system sounded afterwards so I just play with speaker placement, crossover point, and trim levels. For me, this is what has worked.
With that said, I will take the above advice and just use a single output from the receiver to the 2x4 and work from there.


2) Those are 21" subs in 6cuft enclosures. Placement becomes limited when adding mini fridges to the room! I used to tuck a pair of 15's behind the front speakers but no luck doing so when I decided to jump in on the 21's.
Subs are 13ft from the MLP. If/when I add the rear subs, they will be right behind my couch. My couch sits about 1.5ft - 2ft feet off the back wall. Enough room for a custom enclosure to house them both. Either dual sealed chambers or a dual opposed setup. As is, the bass performance is already outstanding with the two 21s. They are wired together off a single channel of a plate amp. I am yet to wire in the big amp and 2x4. Why I'm here as the dumb dumb.


3) As far as my front speakers go. 1st, look at the room. Not ideal. A rental. Left side has a corner and a big window, Right side opens up to the dining/kitchen area. There is a fireplace behind the subs/center. lol Work with what I got. As far as the towers. I used to sell Energy speakers. Always loved the Veritas series and have been using them since roughly 2000. Have used them in many configurations. The reason for the smaller V2.3i towers being used as the mains is simply because they are a better imaging speaker. I used the V2.4i (bigger towers) as my mains for several months. They just don't sound as sweet to me. I listen to a lot of music in 2ch so I want the better sounding tower as my mains. Their placement was dialed in for imaging and midbass well before those subs were ever there. I have a 92" screen that sits between them, so I had to play with how far off the wall they sit and the toe in. No measuring devices, just simply what sounds good with my favorite discs. I then built the subs to fit where they sit. Years before, I played one of my 15" subs all across the front to see if there were any poor spots, all sounded fine in the MLP. The left corner obviously bumped up output a bit but it sounded fine across the front. So I was confident the two 21's where they are would be fine. I retire in less than 3 years. Moving out of Cali, buy a house where I can start over with a dedicated room. But for now, here it is. Hopefully that explains why I like the smaller tower better.
As far as the front wides go, I would love to go about 6" wider, but don't think the "left wide" would sound very good on the other side of that wall sitting outside. The "right wide", is actually in the dining area! lol No WAF factor here. Never again. Get my two sons through college, then retire somewhere else. BTW, I do get what you are saying about the wides. But in my system, as it sits, it works. The two wides sit 13.3ft apart. They are waaay outside of the Prime Spot and sit a good 1.5ft outside of the couch ends. The soundstage extends out way wider than they sit sometimes on certain movies. Running the wides also makes the front stage far more powerful and dynamic. I've lived with these speakers for almost 20 years. Several different models and configurations. The center is actually a bookshelf model I split up. The real center does not perform as well so I use a single bookshelf now and it is fantastic. Those 5 speakers are powered by the monster Cinenova Grande amp. Tons of power. I love it. John Wick 2 club scene is insane!


So, while not ideal, it performs. Just need to get the sub situation dialed. Thanks for the advice. Will read the mentioned threads.....AGAIN. Years ago so have lost whatever was retained. Set it up and start running REW. Go from there.
 
#4,162 ·
As far as my front speakers go...
Yea, I assumed you were limited in where you could place things based on your photo. I just couldn't understand the reasoning behind the smaller mains. I assumed they are smaller mains and not that you actually had your wides inside the mains as that would be even worse.

I know exactly what you mean by your smaller speakers imaging better than the larger ones. I had that same problem with my Revels. The bigger speakers had better sound quality, but didn't image as well as the smaller speakers. Not that they were bad, but just not as good. I'm guessing they were just too big for my room and I had freedom to place the speakers anywhere.
 
#4,165 ·
Adding a DDRC24 to help control my 2 IB subs. I have a Denon x4400 with subHT and XT32.

  • Should I run Dirac for the subs and then run Audyssey so it will have the impact of the Dirac from the DDRC 24?
  • Or should I Audyssey 1st and then run the DDRC through my receiver to get Dirac correction (would later move DDRC to inline with the subs vs it feeding into the receiver)?

Just trying to get the biggest bang for the buck with Dirac as well as Audessy. My room is a bit of a challenge so I need all the correction I can get.

IB subs are behind MLP and are equal distance from MLP, both are identical in construction. Biggest difference is one IB manifold is near a corner and the other isn't.

Thanks!
 
#4,166 ·
IMO, the best function your new MiniDSP can perform for your system is to function as a 2x4HD, i.e. time align and gain match the subs. IOW, Dirac’ing subwoofers won’t produce much performance gain. Even MSO, which does improve the performance of multiple subs, improves two subs only negligibly.

My $.02.

Jeff
 
#4,170 ·
So you are saying Dirac doesn't add much vs REW for the subs?
It’s my opinion which I have seen others offer as well. The big .. BIG .. advantage of the 2x4HD, or the 2x4HD “built into” the DDRC24 is the ability to gain match subs. You mention your subs as being equidistant, a configuration that typically means SubHT will gainmatch them. But with one facing into a corner, I’d guess it may not. So the 2x4HD would help.

I actually have a 2x4HD already but thought Dirac was supposed to be ‘the best’ so purchased a DDRC24 to try out.

Maybe I just keep the 2x4HD and sell the ddrc24.
Hopefully others will chime in with advice. And since you bought the DDRC24 to try, go ahead and give it a fiddle. Dirac makes an entire system shine but for sub-only use, it’s questionable.

Jeff
 
#4,183 ·
Hi Jerry, I'm on the correct thread now for miniDSP how to's.

I'm on page 25, instructions 12-15 "Sub distance tweak". Everything is on and un-muted. Sweep settings set. My ONKYO 787 does not use "Small and Large" nomenclature? I'll set my CC XO to 90. The subs are still set to their lowest value 60 (Polk's dial sweeps from 60-150Hz)? Correct? EQ is still OFF? That AVR has a separate LFE SW setting? What should it be now? And, what should it have been earlier in the tutorial?
Thanks..
 
#4,184 ·
Hi Jerry, I'm on the correct thread now for miniDSP how to's.

I'm on page 25, instructions 12-15 "Sub distance tweak". Everything is on and un-muted. Sweep settings set. My ONKYO 787 does not use "Small and Large" nomenclature? I'll set my CC XO to 90. The subs are still set to their lowest value 60 (Polk's dial sweeps from 60-150Hz)? Correct?
What is that "Polk dial?" If it's a lowpass filter, it should be at 150Hz ... if not defeatable. LFE should also be set as high as possible ... if not defeatable. This gets all of the sub's circuitry as out of the way as possible and lets your AVR's bass management system do the work.

Jeff
 
#4,185 ·
Thanks Jeff.
The Polk dial is the pot control on the sub control plate that sets the XO. So my 60 setting on earlier tests should have been 150, duh, backwards again. The LFE can be set to 200......

Redo time.
 
#4,195 ·
Dirac Live is an automated room correction system, along the lines of Audyssey and others. The MiniDSP implementation of Dirac Live is a full version of the software. On the MiniDSP 88A you will get a full 7.1 room correction, with a very powerful and flexible post-calibration Custom Target editor. Those who have used other room correction solutions and converted to Dirac Live will claim that it is a superior solution. I am among those users.
 
#4,194 ·
Minidsp allows you to EQ your system to your desired frequency response.

More specifically you can go from a super lumpy frequency/ dB line to one that is closer to flat. It’s a room correction tool.

Minidsp’s website isn’t secretive as much as it just assumes, sometimes wrongly so, that you know exactly what their product do.

The two pictures are the after and before of EQ. REW measures the room and then you create peq filters to ‘fix’ the peaks and valleys. These filters are loaded into the minidsp to deliver a flatter line and thus hopefully a better listening experience.
 

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#4,196 ·
Alright, I worded my question poorly, sorry about that. I'm well aware of what a MiniDSP is (I have a 2x4HD) and have extensively used REW. I also know that Dirac is a room correction implementation. What I meant to ask was if we know what Dirac is looking for and changing when you run it on a MiniDSP. I'm particularly interested in how it takes advantage of FIR filters.
 
#4,198 · (Edited)
Is this what you're referring to or is there more detailed information somewhere else? At this point, I understand fundamental differences between linear phase and minimum phase filters but am wondering about how to properly apply them. So if I can manually do what Dirac is doing, I can save myself $200 :)
 
#4,203 ·
I'm not sure what's absurd about my post. We know that the hardware of the MiniDSP 2x4HD is the same as the DDRC-24 so we know the two devices have the same capability. And you'd be using the same mic when taking measurements for both devices (meaning there isn't a special Dirac mic for the DDRC) so that's also a constant. So unless MiniDSP purposefully omits features on the regular 2x4HD plugin that the Dirac plugin can take advantage of, you can manually configure a regular 2x4HD to use the same settings as those the Dirac plugin would. We also know that Dirac is an algorithm that looks at the response readings and deterministically makes decisions about the optimum settings based on criteria that has been preprogrammed into it. So in order to manually reproduce the results of a Dirac calibration, we'd just have to understand how it makes decisions and determines what settings are optimal. And this is just to match it in performance. It's possible, and I'd expect, that their algorithm errs on the side of caution in order to work better over a more varied set of conditions. So if you knew what you were doing, it's possible that you could end up with a better manual calibration than what Dirac could do. The reason I am asking specifically what Dirac is looking for and tuning is so that I can start off by mimicking its behavior in order to have a more guided starting point in learning more about FIR filters.
 
#4,205 · (Edited)
I'm not sure what's absurd about my post.
See below. Special emphasis has been placed on the absurd premise on which your theory is based.
So in order to manually reproduce the results of a Dirac calibration, we'd just have to understand how it makes decisions and determines what settings are optimal. And this is just to match it in performance. It's possible, and I'd expect, that their algorithm errs on the side of caution in order to work better over a more varied set of conditions. So if you knew what you were doing, it's possible that you could end up with a better manual calibration than what Dirac could do.
I think that there are published scientific papers and presentations available that delve deeply into the theories behind Dirac. Deeply. By the world-class PhD’s behind it. Of course they don’t reveal their algorithms, so along with grasping the theories, you’d need to develop ways to implement the theories. So go for it.
 
#4,213 ·
Hi guys,

How should I set my LP filter on the minidsp? Right now I have it "bypassed" as I use the AVR to set the crossover. Is this correct?

Thanks
I could think of a possible use for the MiniDSP's low pass filter, i.e. to protect a sub from receiving very low frequencies that could damage it. Though I don't recall ever reading any specific cases.

Anyone else?

Jeff
 
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