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MiniDSP - Page 61

post #1801 of 2293
Ok, its official. My order has been changed to the Open DRC-AN
post #1802 of 2293
I see that a lot of people are using the MiniDSP for sub EQ'ing...but...
Is a MiniDSP any good for EQ'ing the full range LCR's?

Thanks
post #1803 of 2293
eq'ing full range is generally a bad idea. the wavelengths get too small, so moving your head an inch can give different results.
post #1804 of 2293
^Unless your correcting raw speaker response and not room induced effects right?

Its not clear what he meant though......
post #1805 of 2293
Is there any point to EQ two Polk Audio DSW Pro 660Wi subs?

PS: I don't listen very loud, wife gets suicidal when turning the knob anywhere near -10 dB.

Denon AVR-X1000
Monitor Audio Bronze BX2
Polk Audio DSW Pro 660Wi
post #1806 of 2293
I ordered both a balanced and unbalanced 2X4 (I know I only needed balanced but decided just to buy both for the heck of it) about 6 months ago for a dual 18" Dayton sub I planned to build. Finally got it all together and tried hooking up the balanced but barely get any ouput. With the gain turned all the way up on a ep4000 it just barely tickles the signal lights. I have an anthem mrx-500 that when hooked up directly to the ep4000 drives it just fine. I tried changing jumper selections (2 to .9) and have checked and rechecked all wiring but to no avail. The input signal shows that I'm getting plenty of input, and the output shows that I should be getting plenty of output (checked and rechecked all settings in mini software also). Decided to try the unbalanced and it drives the ep just fine. I then tried measuring the voltage coming out of the balanced and I cant seem to get anything measureable. If the .9v output of the unbalanced is enough to drive the ep then surely the balanced should drive it without something like a cleanbox in the chain.
Am I missing something or did I just get a bad unit????? Any thoughts or suggestions would be greatly appreciated!
post #1807 of 2293
Quote:
Originally Posted by ASU View Post

I ordered both a balanced and unbalanced 2X4 (I know I only needed balanced but decided just to buy both for the heck of it) about 6 months ago for a dual 18" Dayton sub I planned to build. Finally got it all together and tried hooking up the balanced but barely get any ouput. With the gain turned all the way up on a ep4000 it just barely tickles the signal lights. I have an anthem mrx-500 that when hooked up directly to the ep4000 drives it just fine. I tried changing jumper selections (2 to .9) and have checked and rechecked all wiring but to no avail. The input signal shows that I'm getting plenty of input, and the output shows that I should be getting plenty of output (checked and rechecked all settings in mini software also). Decided to try the unbalanced and it drives the ep just fine. I then tried measuring the voltage coming out of the balanced and I cant seem to get anything measureable. If the .9v output of the unbalanced is enough to drive the ep then surely the balanced should drive it without something like a cleanbox in the chain.
Am I missing something or did I just get a bad unit????? Any thoughts or suggestions would be greatly appreciated!

Bump! I am getting ready to order a MiniDsp, and would like to make sure that the balanced version of the 2 by 4 advanced plug in will play nice with my new, (old), Denon AVR-3310.
post #1808 of 2293
Quote:
Originally Posted by Martycool007 View Post

Bump! I am getting ready to order a MiniDsp, and would like to make sure that the balanced version of the 2 by 4 advanced plug in will play nice with my new, (old), Denon AVR-3310.

Yes you will just need the right connections. RCA to Phoenix in and out depending on your subs. I will post more info I was given soon
post #1809 of 2293
Today I have put my new Open DRC-AN into the signal chain. I measured from each sub physically to within an 1/8 of an inch to the tip of the audyssey mic and ran a one mic run to see each distance setting to see if each time delay is equal. I got 16.2 ft and 16.4ft. Yesterday it was 12.8 before the mini dsp in the signal chain. Anyway a few pieces of info here. Looking for some answers. When I first plugged in my mini dsp and installed the software everything worked great. I could go in and choose any frequency, say 55hz, boost it in 0.5db increments and the differences were audible with enough db's boosted. I was thinking to myself, this is gonna be nice. The mute and gain controls on the mini dsp interface on my Mac screen all worked. So I decided I was going to run Audyssey any then get a measurement with just audyssey run and then one with audyssey and some mini dsp EQ applied to see how well it could counteract what audyssey left. Like boost the null areas. Anyway after I ran audyssey and entered REW to take my measurements all of the sudden my mini dsp controls were all unresponsive. I took a successful just Audyssey measurement and then engaged the dsp but got the same measurement. With that second measurement being identical I then went into the dsp interface screen and everything was unresponsive that just worked 10 minutes prior. I will post in the dsp forums in hope of some help. One weird thing is the two submersives were set low on the gain knobs (like 4 clicks from the bottom) and the bass levels didn't change when I simply installed the mini dsp into the signal chain. When I went to run Audyssey I had to get the gain up closer to '15' on the gain dial to achieve -1.5db on one and -1.0db on the other. I have a few mysteries here. I'm sure in time I can work them out. But any advice is surely appreciated.

Basically it worked and then I had to change a few settings to get my UMM-6 mic to respond with REW. I have sound flower installed that is used to get my mic to respond with REW. But it continues to pass the signal through so why would all of the sudden the mute, and parametric, EQ any gain be unresponsive?
Edited by jlpowell84 - 10/13/13 at 9:42pm
post #1810 of 2293
Why did you go with the Open DRC-AN in leu of the regular MiniDsp 2 by 4 ballances?
post #1811 of 2293
Quote:
Originally Posted by Martycool007 View Post

Why did you go with the Open DRC-AN in leu of the regular MiniDsp 2 by 4 ballances?

Well it seemed like a nicer unit and it has XLR in and out. I know it's just a setting somewhere but usually I can figure these things out. I'll have more time tonight
post #1812 of 2293
I have an unbalanced 2x4. I have 3 subs on outputs 1,3, and 4 and am using the 4-way advanced plugin. I am feeding the inputs with sub1 and sub2 outputs from a Denon 4311. I want the sub1 input to output to output #3 and #4, and sub2 input to output to output #2.

However, both inputs are outputting to all 4 outputs. When I run the AVR channel levels all 4 outputs are active with both discrete sub inputs. How can I change that? The manual says that input #1 should be going to output #1 and #3 and input #2 to output #2 and #4. That's not happening for me and I'm sure I'm missing something very obvious!

Thanks!
post #1813 of 2293
The 4-way advanced plug in only accepts a signal from one input and then outputs it to all 4 channels.

You need the 2 way xover advanced to accept input from both sub outs. There are other plugins that will do it also but I use the 2-way advanced.

Moto
post #1814 of 2293
Is there a way on the open DRC to run only one sub out from my receiver and then 2 out to my dual subs? Right now I have sub 1&2 out from my receiver to input 1&2. I would like to run just one input and then both out
post #1815 of 2293
Quote:
Originally Posted by MX48 View Post

The 4-way advanced plug in only accepts a signal from one input and then outputs it to all 4 channels.

You need the 2 way xover advanced to accept input from both sub outs. There are other plugins that will do it also but I use the 2-way advanced.

Moto

Thanks! It was the 2 way Advanced 2.1 I needed, not the plain Jane 2 way advanced.
post #1816 of 2293
Quote:
Originally Posted by jlpowell84 View Post

Is there a way on the open DRC to run only one sub out from my receiver and then 2 out to my dual subs? Right now I have sub 1&2 out from my receiver to input 1&2. I would like to run just one input and then both out

I see you can link channels, if you open PEQ or Xover window in the top left corner there is an icon called select channel, from there you can link channel 1 to 2. I haven't tried that yet.
post #1817 of 2293
Quote:
Originally Posted by nb67 View Post

I see you can link channels, if you open PEQ or Xover window in the top left corner there is an icon called select channel, from there you can link channel 1 to 2. I haven't tried that yet.

+1

The feature basically copy's the settings of one channel over to the other channel.
post #1818 of 2293
Quote:
Originally Posted by edoggrc51 View Post

+1

The feature basically copy's the settings of one channel over to the other channel.

Yes, that is what i did. Link them together. I am currently here. Playing with another config developing a steeper house curve. This is best I have so far.



wink.gif
post #1819 of 2293
What exactly are the FIR filter benefits that can be uploaded into the open DRC model? I see from the mini dsp site that third party software is used to develop these filters. Is it just that they are more accurate than PEQ?
post #1820 of 2293
Hey I saw this Mini-DSP thread at the top of the DIY section so I thought I'd add this info and maybe get some feedback as well.

I had a hum in my new setup and after a bit of research I came across this article from Peavy (my amp is a Peavy IPR2). It suggests to float pin 1 of the balanced connection to remove the hum. Sure enough, it worked.

Here is the article - http://www.peavey.com/support/technotes/soundsystems/humandpin.cfm

My setup is unbalanced input from Pioneer AVR to a balanced Mini-DSP unit, then out of the Mini-DSP with balanced XLR into my Peavy amp. I have the input jumper set to 2.0v.

My question is, since removing pin one on the Mini-DSP side solves the hum problem, should I jump negative and shield per instructions? I tried both ways, jumped and not jumped, and I got hum free bass to my subs with both configurations.

I'm thinking since it's still going into a balanced input, and the article states specifically to leave the shield (pin 1) connected at the terminating end, that I'd not jump the negative and shield on the output of the minidsp....

Anyways, if no one can help at least there's some solid input and a possible solution for anyone who encounters the hum.
Edited by pdxrealtor - 10/20/13 at 10:44am
post #1821 of 2293
Quote:
Originally Posted by jlpowell84 View Post

What exactly are the FIR filter benefits that can be uploaded into the open DRC model? I see from the mini dsp site that third party software is used to develop these filters. Is it just that they are more accurate than PEQ?

I would like to know the answer to this as well
Bump!
post #1822 of 2293
Hi Jlpowell and Marty,
Quote:
Originally Posted by jlpowell84 View Post

What exactly are the FIR filter benefits that can be uploaded into the open DRC model? I see from the mini dsp site that third party software is used to develop these filters. Is it just that they are more accurate than PEQ?
There are two main benefits of FIR filters over IIR filters (the normal miniDSP PEQ filters are bi-quad IIR filters).

The more desirable benefit is that a FIR filter has a linear phase-response. That is to say that the audio that leaves the filter does so after a fixed, known delay from when the audio entered the filter. So all phase information is preserved. An IIR filter (and therefore a PEQ filter) has a non-linear phase-response, meaning different frequencies leave the filter after different delays through the filter. So you cannot depend on phase relationships being preserved through an IIR filter.

The other advantage of a FIR filter is the ease of designing it. If you have software that can perform a discrete Fourier transform and an inverse discrete Fourier transform, then you can calculate the coefficients of a FIR filter. My favorite advantage is that you can "draw" an arbitrary frequency-response curve, and then calculate the coefficients that will approximate that frequency-response.

The disadvantage of a FIR filter is that an accurate one can take hundreds of times the memory and processing power of an IIR filter.
post #1823 of 2293
as far as fir vs iir for crossovers, is it audible under music conditions or only some controlled contrived scenarios?

i thought one reason why linkwtiz 4th order was used was that its 360 degree phase roll isn't actually audible, or do i have some piece of that misunderstood?
post #1824 of 2293
Hi LTD,
Quote:
Originally Posted by LTD02 View Post

as far as fir vs iir for crossovers, is it audible under music conditions or only some controlled contrived scenarios?
Fair question - and I don't know the answer. I have heard that we can't really hear the phase relationships of different frequencies. I have also heard that the phase relationships between the harmonics of a musical instrument are what make it sound as it does. I don't know which is true - I just do the math.

Quote:
i thought one reason why linkwtiz 4th order was used was that its 360 degree phase roll isn't actually audible, or do i have some piece of that misunderstood?
You understand that correctly. Personally, I think the Linkwitz–Riley filter is a piece of brilliance. It is actually a cascade of Butterworth IIR filters, whose total phase-delay goes full circle back to zero. Can't argue with that!

I know that the phase-delay of IIR filters is an issue in many fields, like communications, but I'm not sure how important it is with audio. I probably should have mentioned that my above post talks about FIR and IIR filters in general, and skirts the topic of its relevance to audio. My bad.
post #1825 of 2293
Does the balanced mini dsp put out the same volts even if used in un balanced mode?
post #1826 of 2293
answer my own question...

Dr. Floyd Toole: "It turns out that, within very generous tolerances, humans are insensitive to phase shifts. Under carefully contrived circumstances, special signals auditioned in anechoic conditions, or through headphones, people have heard slight differences. However, even these limited results have failed to provide clear evidence of a 'preference' for a lack of phase shift. When auditioned in real rooms, these differences disappear.."
post #1827 of 2293
"I probably should have mentioned that my above post talks about FIR and IIR filters in general, and skirts the topic of its relevance to audio. My bad."

no worries. thanks for the comment.

if absolute phase did matter, could an all pass filter somehow "roll back" or otherwise compensate the LR24 back to linear phase or whatever the original signal was?
post #1828 of 2293
Hi LTD,
Quote:
Originally Posted by LTD02 View Post

if absolute phase did matter, could an all pass filter somehow "roll back" or otherwise compensate the LR24 back to linear phase or whatever the original signal was?
Theoretically, yes. I recently learned how to compute an all-pass FIR filter that can manipulate phase, but I'm not sure you can easily do it with an IIR filter.

And if you need a FIR filter to fix the phase, then that makes it somewhat impractical, as you could have done the the whole job with a FIR filter. Adding the FIR filter has negated the advantage of the IIR filter: the fact that it is computationally inexpensive.

Then again, a Linkwitz-Riley controls phase with a series of IIR filters, so it might be possible to correct phase using only IIR filters.
post #1829 of 2293
A big advantage of FIR is they, by design, are inherently stable since there is no feedback. Since they don't require feedback they do very well in a Multiply/Accumulate which are 1 cycle operations in most DSP's. In short, for complex filtering a FIR just is easier to design at the expense of memory only (execution time is about the same). Since memory is a joke these days...why not take the easy route.

As an example, I have a FIR filter in a FPGA running @ 250 MHz. I parallel ~50 of these and just go to town. My effective bandwidth is borderline insane for little $. Best part is the coefficients come straight out of Matlab with the click of a button. However, for simple 1-4th order filters...IIR's are pretty safe and worth the effort.
post #1830 of 2293
I wish I knew what y'all were saying. smile.gif basically I know my Open DRC AN can upload FIR filters and was trying to understand on a VERY basic level why the MIGHT be better than just using the PEQ already on the plugin software smile.gif
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