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Discussion Starter · #41 ·

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Discussion Starter · #44 ·
Incredible source of information here. Time to do some homework.

Thank you for putting so much of your time and effort in this, @mthomas47 !!
You are very welcome! I hope that something in the Guide ends up being helpful! :)
 

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The OP was a really good read. Extremely detailed, yet written in a way that is easy to digest (my eyes start to glaze over when guys start comparing Xmax, TS parameters, port length etc, lol). I just upgraded to a Marantz SR6011 with XT32 and am impressed with it compared to standard Multi EQ which I was dealing with before.

Here is a question for the board, I also have a mini dsp 2x4 which I've not hooked up, along with REW and a calibrated MiniDsp mic. My subs are two of the now notorious EPIK Legends, which have dual opposed 12' drivers in a relatively small sealed cabinet. One had an amp die a couple years ago which I replaced with a 300 watt Bash plate amp from Parts Express, the other has the original 300 watt amp but it is about to die and I'm considering replacing it with a similar amp or bumping up to a 500 watt Dayton plate amp. I remember reading somewhere that the original amp heavily boosted the 30 hz range to get the numbers and sound the builder was shooting for. A majority of he amps in these units died prematurely with some blaming poor heat management combined with a 300 watt amp being overdriven from the 30 hz boost. I know most manufacturers add some level of EQ to sealed cabinets using a Linkwitz Transform or some other calculation. It is clear that the sub with the original amp goes deeper than the unboosted sub which only makes sense. With replacing both subs and starting from scratch not an option at this time, would it be best to:

A) Get the same 300 watt plate amp for the second sub as the first which will make them both essentially the same sub again, albeit not as beefy below 40hz? Then run XT32 for both and add a less severe boost (+3db) around 30 hz in Audyssey to help flesh things out a bit?

B) Buy an upgraded 500 watt plate amp for $250 which should allow even more boost (+6db or more) at 30 hz for that individual sub. Then EQ the two subs separately using MiniDSP and then run XT32? Will both room correction softwares play nice together or will Audyssey try to undo the minidsp correction?

C)Seal up both subs, disconnect their plate amps and buy a Barranger INUKE 3000DSP to run both subs. That way I'll have a decent power amp with DSP when I build my dual DIY Stonehenges or Marty Cubes next winter and throw the epics in the woodchipper. LOL.

I'm leaning toward C, but I am really interested to see if anyone else has ran MiniDsp along with Audyssey XT32 and what are the pros and cons?

Thanks for indulging me!

If it was me, I would get the behringer;
https://www.parts-express.com/behringer-nu3000dsp-inuke-3000-watt-power-amplifier-with-dsp--248-6706
Plenty of power, and no extra boost at certain frequencies.


Let the Audyssey XT32, take care of that:)
I would also leave the plate amp in place, but disconnect, since it would be a big hole to patch and seal.
Then just buy an RCA plate to accept the wires from the Inuke, just a small hole (round or square, depending of what you get) to cut and place in position.


Ray
 

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Discussion Starter · #46 · (Edited)
The OP was a really good read. Extremely detailed, yet written in a way that is easy to digest (my eyes start to glaze over when guys start comparing Xmax, TS parameters, port length etc, lol). I just upgraded to a Marantz SR6011 with XT32 and am impressed with it compared to standard Multi EQ which I was dealing with before.

Here is a question for the board, I also have a mini dsp 2x4 which I've not hooked up, along with REW and a calibrated MiniDsp mic. My subs are two of the now notorious EPIK Legends, which have dual opposed 12' drivers in a relatively small sealed cabinet. One had an amp die a couple years ago which I replaced with a 300 watt Bash plate amp from Parts Express, the other has the original 300 watt amp but it is about to die and I'm considering replacing it with a similar amp or bumping up to a 500 watt Dayton plate amp. I remember reading somewhere that the original amp heavily boosted the 30 hz range to get the numbers and sound the builder was shooting for. A majority of he amps in these units died prematurely with some blaming poor heat management combined with a 300 watt amp being overdriven from the 30 hz boost. I know most manufacturers add some level of EQ to sealed cabinets using a Linkwitz Transform or some other calculation. It is clear that the sub with the original amp goes deeper than the unboosted sub which only makes sense. With replacing both subs and starting from scratch not an option at this time, would it be best to:

A) Get the same 300 watt plate amp for the second sub as the first which will make them both essentially the same sub again, albeit not as beefy below 40hz? Then run XT32 for both and add a less severe boost (+3db) around 30 hz in Audyssey to help flesh things out a bit?

B) Buy an upgraded 500 watt plate amp for $250 which should allow even more boost (+6db or more) at 30 hz for that individual sub. Then EQ the two subs separately using MiniDSP and then run XT32? Will both room correction softwares play nice together or will Audyssey try to undo the minidsp correction?

C)Seal up both subs, disconnect their plate amps and buy a Barranger INUKE 3000DSP to run both subs. That way I'll have a decent power amp with DSP when I build my dual DIY Stonehenges or Marty Cubes next winter and throw the epics in the woodchipper. LOL.

I'm leaning toward C, but I am really interested to see if anyone else has ran MiniDsp along with Audyssey XT32 and what are the pros and cons?

Thanks for indulging me!
Hi,

First, thanks for the compliment! I will start the conversation, and then perhaps some others will chime-in. There are two schools of thought with respect to using both a miniDSP and Audyssey (in whatever version). If your native frequency response is very bad, it is probably better to use the miniDSP first, and then let Audyssey add some polish to the final result. If you are able to get a pretty decent response by just using Audyssey, then you can use your miniDSP to add some final tweaks, such as the creation of a house curve at particular frequencies. There is a certain amount of trial-and-error which may be required, and obviously being able to measure your results with REW would be helpful.

It is important to remember that all versions of Audyssey, including XT-32, are going to EQ both subs as one, based on their combined SPL at every frequency. So, Audyssey is most effective when the subs in a system have similar native frequency responses. Of course, individual room placement will influence that native frequency response in potentially unpredictable ways, in any event. But, I think that your task of achieving a good frequency response, and a more uniform increase in SPL, will be greater if you start with two subs having similar capabilities at all frequencies. So, I would probably not lean toward B).

I would lean toward either A) or C) as both of those options would allow you to start with a more level playing field. But, I don't know enough about DIY to give you good advice on C). I might have a little concern about how the two Epic subs would function with the iNuke. Someone like LTDO2 could probably advise you much better on that sort of thing.

Regards,
Mike

Edit: Ray is much faster than I am.
 

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Discussion Starter · #48 ·
did the write up include differences for stereo setup vs movie setup?
Hi Torii,

Sorry I missed this post earlier. The Guide primarily concentrates on 5.1 applications, but much of the discussion would be applicable to stereo as well. Was there something in particular that you were thinking about with respect to stereo?

One difference for me would probably be the fact that most stereo music recordings would have very little bass under about 50Hz, so the use of subwoofers, and the application of bass boosts, might be very different than it would be for a 5.1 movie. I do mention the difference in bass content in most non bass-enhanced music.

Speaking personally, the settings I use for my music listening sessions are very different from my action/blockbuster movie watching. But, I suspect that is a YMMV proposition, depending on our music preferences among other things.

Regards,
Mike
 

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LOL


And so You were on post #41 , vs my post on #42 :D


Ray
No matter who answered first, I appreciate both of you gents offering your insight. I'm going to buy the INuke with DSP and run both subs with it. Maybe I'll sell the minidsp cheap or pay it forward to my 16 year old next door neighbor who is just getting into car audio and has a ported JL sub in his trunk. I'll report my findings when I make the move.
 

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Mike, i just read the section of "increasing volume with two sub woofers". I havent finished my first cup of coffee yet so bare with me. Since i always thought adding 5db trim per sub out (would) equal 10 total DB's of boost, i find this section very interesting.

Am i understanding correctly that if your avr has two sub outs, one to each identical sub,,,, and although audyssey is trying to set (all) channels to say 75db's, it is actually combining both sub channels to equal 75db's (total) despite having audyssey running sweeps separately? Thats what i'm understanding (if i'm awake enough). If thats the case, then i completely get the math with regards to adding trim via LFE channel equaling 5db total, not 10.

(If) so far i'm correct in my understanding, how then would it play out if the boost was added through individual sub gain, not avr trim? If i added 5DB's of gain per sub what would that equate to, 5DB total, or 10?
 

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Discussion Starter · #51 · (Edited)
Mike, i just read the section of "increasing volume with two sub woofers". I havent finished my first cup of coffee yet so bare with me. Since i always thought adding 5db trim per sub out (would) equal 10 total DB's of boost, i find this section very interesting.

Am i understanding correctly that if your avr has two sub outs, one to each identical sub,,,, and although audyssey is trying to set (all) channels to say 75db's, it is actually combining both sub channels to equal 75db's (total) despite having audyssey running sweeps separately? Thats what i'm understanding (if i'm awake enough). If thats the case, then i completely get the math with regards to adding trim via LFE channel equaling 5db total, not 10.

(If) so far i'm correct in my understanding, how then would it play out if the boost was added through individual sub gain, not avr trim? If i added 5DB's of gain per sub what would that equate to, 5DB total, or 10?
Hi Joe,

Some of this stuff makes my head spin sometimes, regardless of coffee. Seriously! Audyssey and all other forms of automated calibration with which I am familiar, sum the SPL from multiple subwoofers. So, we use the first test tone for level-matching, and for setting the AVR trim levels on multiple subs individually. And, the two, or four, or eight subwoofers in our systems are calibrated to produce a combined volume of 75db, as measured at the MLP in microphone position 1.

After the calibration, if we raise the volume symmetrically, using either the gain controls on the subs, or the trim controls in our AVR's, the net increase will still be the summed number of the two subs. So, +5 in gain from two subs (or from ten subs) will still equal +5db. The same thing will be true for trim increases.

Asymmetrical increases are a little different, but still follow the same summed rule, as explained in this section of the Guide:

http://www.avsforum.com/forum/113-s...subwoofer-calibration-bass-preferences.html#E

We still have the full benefit of our extra headroom from dual subs available to us, but we have to utilize that additional headroom in the way I described above. If we want +10db, for instance, we have to increase each subwoofer by that amount using either sub gain, or AVR trim, or a combination of the two.

Regards,
Mike
 

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Hi Torii,

Sorry I missed this post earlier. The Guide primarily concentrates on 5.1 applications, but much of the discussion would be applicable to stereo as well. Was there something in particular that you were thinking about with respect to stereo?
was just wondering maybe how its done and any benefits? or why its done.
 

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Hi Joe,

Some of this stuff makes my head spin sometimes, regardless of coffee. Seriously! Audyssey and all other forms of automated calibration with which I am familiar, sum the SPL from multiple subwoofers. So, we use the first test tone for level-matching, and for setting the AVR trim levels on multiple subs individually. And, the two, or four, or eight subwoofers in our systems are calibrated to produce a combined volume of 75db, as measured at the MLP in microphone position 1.

After the calibration, if we raise the volume symmetrically, using either the gain controls on the subs, or the trim controls in our AVR's, the net increase will still be the summed number of the two subs. So, +5 in gain from two subs (or from ten subs) will still equal +5db. The same thing will be true for trim increases. asymmetrical increases are a little different, but still follow the same summed rule, as explained in this section of the Guide: http://www.avsforum.com/forum/113-s...subwoofer-calibration-bass-preferences.html#D

We still have the full benefit of our extra headroom from dual subs available to us, but we have to utilize that additional headroom in the way I described above. If we want +10db, for instance, we have to increase each subwoofer by that amount using either sub gain, or AVR trim, or a combination of the two.

Regards,
Mike
Yes some of this stuff does make my head spin. Example going from one sub doubling to two subs can equate to 6DB's more output, yet when it comes to just the doubling of amp power, this only equates to 3DB's more output.

I'm blown away by all the work put into your now sticky Mike. Geez you could easily be a professional writer. Maybe you are;)
 

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Discussion Starter · #54 ·
was just wondering maybe how its done and any benefits? or why its done.
I'm still not positive that I understand what you are asking, but I will take a crack at it anyway, and see what happens. :p

Room EQ is preformed in order to reduce unwanted interactions between speakers/subwoofers and the room in which they are placed. So, room EQ is equally relevant to both music and movie applications. But, the settings we choose to use (and particularly the amount of bass boost we may add) could certainly change as we move between 5.1 movies with substantial low-bass content, and two-channel music without that kind of content.

In my specific case, I use little if any additional bass when I listen to music played by acoustic instruments, because I know what those instruments, and that music should sound like, and I prefer it to be as natural sounding as possible. For a movie featuring a lot of special effects, on the other hand, there is no natural standard in play for me, and I just want a lot of low-bass SPL and tactile response in order to enjoy the excitement of the movie. I imagine that people listening to bass-enhanced music, such as Dubstep, would employ more bass boost than they might for other types of music. But, that's one of many places where personal preference comes in.

The main thing for me is to distinguish between room EQ, which doesn't change regardless of our listening material; and our settings, such as Audyssey versus Audyssey Flat, DEQ on or off, or independent bass boosts, which might change depending on what we are listening to. Is this what you had in mind?

Regards,
Mike
 

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Discussion Starter · #55 ·
Yes some of this stuff does make my head spin. Example going from one sub doubling to two subs can equate to 6DB's more output, yet when it comes to just the doubling of amp power, this only equates to 3DB's more output.

I'm blown away by all the work put into your now sticky Mike. Geez you could easily be a professional writer. Maybe you are;)
Thank you very much, Joe! :) I actually do a fair bit of writing in my professional career.

I agree with you about how confusing some of the audio rules and relationships are. Writing them out, and then editing them several times for clarity, has helped me a lot in understanding some of the rules and relationships. But, I still find myself referring to the Guide when I get confused. :p
 

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Wow, great write up Mike. Many people will be served well by your work.

Id also like to say you are without a doubt the one most cordial AVS'ers. Ive never seen you direct some sarcasm toward someone even when they probably deserved much more than that. Always taking the high road while keeping the conversation intelligent.

Kudos to you!:cool:
 

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Discussion Starter · #58 ·
I read some articles from time to time like this one...http://kenrockwell.com/audio/stereo-subwoofers.htm

just figured you might have some input on the topic.
Ah, I see where you were going now. This is a topic that has been debated quite a bit with some audio experts saying it doesn't make any difference and others saying it does. My own opinion is that it is very difficult to achieve stereo subwoofers with a traditional HT system. (I hope that no one asks me to try to explain this, because even the real experts disagree on the subject. And, I am not a real expert.)

To me, the best of both worlds is probably to have very capable full-range speakers which are individually calibrated and EQed and which can play the low-frequencies desired for stereo music. How far below a typical crossover of 80Hz the low-frequencies would actually extend is the first question. Whether the low-frequencies would be individually directed into separate channels in the recording would be a second question. And, how much we would be able to localize the low-frequencies as coming from one speaker/subwoofer, or another, would be a third question.

But, with really capable full-range speakers set to Large, we could at least take questions 1 and 3 out of the equation. Question 2: how much channel-specific low-bass content actually exists in stereo recordings, would still remain a valid question. I am personally convinced that many stereo recordings have bass down to at least about 60Hz or 80Hz in individual channels, although I could be wrong about that.

Regards,
Mike
 

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Discussion Starter · #59 ·
Wow, great write up Mike. Many people will be served well by your work.

Id also like to say you are without a doubt the one most cordial AVS'ers. Ive never seen you direct some sarcasm toward someone even when they probably deserved much more than that. Always taking the high road while keeping the conversation intelligent.

Kudos to you!:cool:
Thank you very much! I appreciate your nice comments and support. :)
 

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wow, just now seeing this. I haven't thoroughly read through it all yet, but just skimmed though it right quick to check it out with limited time today and looks amazing. I'm sure this write up in this thread (as with all your posts) are going to be extremely helpful to this community, well written and easy to digest.

Awesome thread! I'm gonna go read through it thoroughly when I get a chance sometime this weekend.
 
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