|
|
Post by jjkessler on Mar 3, 2016 22:06:22 GMT -5
I am playing with my Crossovers s bit and plan on running Dirac again soon. I have Axiom M80 mains and dual SVS Pb-12 Plus subs set up in stereo mode.
The amplifier on the mains (actually on all 7 channels) are XPA-1L's
The SVS configuration tool called Merlin suggest crossing at 60hz versus the typical 80hz with the low pass filter set to 40hz and 24db slope
I am using no port plugs on the Pb-12 pluses so they are in the 20hz tune (capable of 16hz)
The room is 20' X 40' with mostly 9' ceilings. The subs are both on the front wall on either side of my center channel 1/3 on either side of the short walk and flanked by the M80 mains. Listening is 50/50 movie and 2 channel
Wanted to get the boards thoughts on the 60hz sub crossover before I start making some changes? Would it make sense to change the tune to 16hz bottom end or keep it at 20hz?
It seems like they are wanting the M80 mains to handle a bit more of the bass before handing off to the 2 subs. Seems to make sense to possibly get better response / definition on the higher bass area
I am not sure how well the performance will truly be between 20Hz and 16hz tunes so, left it at 20Hz for now. The response curve on the PB-12 Plus seems to show a bit of struggle towards 16 Hz but, am curious to try it out
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Mar 3, 2016 23:42:29 GMT -5
What does the response look like using one sub? When I tried using my xmc in stereo/dual mono mode it couldn't align the separate groups of subs properly and ended up with a poorer response than with less subs.
Do you have a way to check actual response of the speakers and subs ? Or are you going off what the dirac measurements say ?
As far as port tuning, 20hz mode is max output mode... 16hz will lower overall output but push the response lower.. As long as plugging a port doesn't cause audible chuffing, I would run for extension over output .
|
|
|
|
Post by jjkessler on Mar 4, 2016 6:55:11 GMT -5
I was thinking the same thing in regards to trading extension over volume as I never run at max volume anyway.
Should I consider a processor just for the subs to set them up right outside the XMC-1 and if so, what's a good unit to use?
|
|
|
|
Post by etc6849 on Mar 4, 2016 8:33:14 GMT -5
Dual mono subs will ALWAYS work better than stereo subs or a single sub if setup properly . Has to do with how the subs interact with your room.
No reason to buy a separate controller if your subs have level and phase adjustments, why not use them?
I would Google for how to align phase and level for the two subs using REW and a calibrated mic. Then use a wye adapter off the XMC-1's left sub output.
Also, just because the response plot looks better doesn't mean too much. The waterfall plot in REW will tell a much better story and show you what ringing is audible plus any dips too.
You will unlikely hear a dip in a resp plot, but I promise you will hear ringing at problem frequencies.
|
|
|
|
Post by jjkessler on Mar 4, 2016 8:54:06 GMT -5
So, dual mono, 16Hz tune is a better choice. The subs have a DSP built in. I am using XLR connections so I would need a breakout box
Do I loose any R channel content in going dual mono or, does the XMC-1 blend it?
|
|
|
|
Post by etc6849 on Mar 4, 2016 10:11:46 GMT -5
I use the Emotiva xlr wye breakout box off left sub output. If subs are: 1. matched and set the same 2. room, placement, and furniture are symmetrical 3. and distances to listening position the same the wye adapter will work fine without matching phase. So, dual mono, 16Hz tune is a better choice. The subs have a DSP built in. I am using XLR connections so I would need a breakout box Do I loose any R channel content in going dual mono or, does the XMC-1 blend it? |
|
|
|
Post by etc6849 on Mar 4, 2016 10:16:46 GMT -5
Assuming you use Dirac which will match mono sub phase to main speakers. This is VERY important to do. I use the Emotiva xlr wye breakout box off left sub output. If subs are: 1. matched and set the same 2. room, placement, and furniture are symmetrical 3. and distances to listening position the same the wye adapter will work fine without matching phase. So, dual mono, 16Hz tune is a better choice. The subs have a DSP built in. I am using XLR connections so I would need a breakout box Do I loose any R channel content in going dual mono or, does the XMC-1 blend it? |
|
|
|
Post by jjkessler on Mar 4, 2016 14:27:43 GMT -5
The PB-12 Plus does full signal pass through on the outputs. I could go output from one sub to input to the other in dual Mono. Any drawbacks to doing this? The distance between subs is about 12'
|
|
|
|
Post by thezone on Mar 5, 2016 1:36:16 GMT -5
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Mar 5, 2016 9:56:28 GMT -5
Assuming you use Dirac which will match mono sub phase to main speakers. This is VERY important to do. I use the Emotiva xlr wye breakout box off left sub output. If subs are: 1. matched and set the same 2. room, placement, and furniture are symmetrical 3. and distances to listening position the same the wye adapter will work fine without matching phase. The xmc does a poor job of aligning subs to mains, it does a poorer job of aligning dual mono subs to each other. |
|
|
|
Post by jjkessler on Mar 5, 2016 14:45:38 GMT -5
That article is excellent and I'm going try their approach and see how it signs
|
|
|
|
Post by jjkessler on Mar 5, 2016 15:24:26 GMT -5
So, on the XMC-1, you can configure the 2 subs as dual mono. According to the manual, this still sums the signal into mono but, gives you separate control of each sub.
Or
I physically cable both subs as one using the L sub out with a Y
Which is the better way to go in general and when using Dirac ?
|
|
|
|
Post by thezone on Mar 5, 2016 18:16:19 GMT -5
That article is excellent and I'm going try their approach and see how it signs I particularly like the advice about setting the mains speaker distance in the pre/pro to 7 feet and the subs distance to 18-20 feet in order to get the subs to fire 10msec earlier and correctly align the timing issues between the subs and mains. This really works. |
|
|
|
Post by etc6849 on Mar 7, 2016 19:16:10 GMT -5
Can you post REW measurements? Time aligning speakers is something any AVR made into the last few years should do very well. The XMC-1's Dirac works great for me. I'm not seeing any phase issues with mine. Assuming you use Dirac which will match mono sub phase to main speakers. This is VERY important to do. The xmc does a poor job of aligning subs to mains, it does a poorer job of aligning dual mono subs to each other. |
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Mar 7, 2016 20:03:20 GMT -5
Can you post REW measurements? Time aligning speakers is something any AVR made into the last few years should do very well. The XMC-1's Dirac works great for me. I'm not seeing any phase issues with mine. The xmc does a poor job of aligning subs to mains, it does a poorer job of aligning dual mono subs to each other. All my graphs should be in one of the dirac threads. It takes a 1.5ms delay to align my subs to the mains.. Or i have a 10db dip at crossover frequency. I run my 4 subs as one from the left sub out. When i tried to run my front and rear pairs as dual mono.. It was a bloody mess. |
|
|
|
Post by etc6849 on Mar 8, 2016 9:03:08 GMT -5
Can you post REW measurements? Time aligning speakers is something any AVR made into the last few years should do very well. The XMC-1's Dirac works great for me. I'm not seeing any phase issues with mine. All my graphs should be in one of the dirac threads. It takes a 1.5ms delay to align my subs to the mains.. Or i have a 10db dip at crossover frequency. I run my 4 subs as one from the left sub out. When i tried to run my front and rear pairs as dual mono.. It was a bloody mess. Here is one of my measurements.
Note there are very few phase changes at the mlp. Mains are crossed at 80 Hz to dual subs. I use the default Dirac tilted house curve.
For four subs you need a miniDSP to first time align everything. In fairness no pre/pro in this price range time aligns four subs.
I do use a wye adapter from left sub out and have everything very symmetrical and calibrated for only the mlp.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Mar 8, 2016 10:01:32 GMT -5
All my graphs should be in one of the dirac threads. It takes a 1.5ms delay to align my subs to the mains.. Or i have a 10db dip at crossover frequency. I run my 4 subs as one from the left sub out. When i tried to run my front and rear pairs as dual mono.. It was a bloody mess. Here is one of my measurements. Note there are very few phase changes at the mlp. Mains are crossed at 80 Hz to dual subs. I use the default Dirac tilted house curve. For four subs you need a miniDSP to first time align everything. In fairness no pre/pro in this price range time aligns four subs. I do use a wye adapter from left sub out and have everything very symmetrical and calibrated for only the mlp. I was running them in groups of two. It appears you are one of the lucky ones. But try running the subs in dual mono,I'd be willing to bet you'd have a wonky response. My room is in pieces at the moment due to a projector, amplifier and subwoofer upgrade/change. I'll repost my graphs when all is put back together. |
|
|
|
Post by etc6849 on Mar 8, 2016 13:55:35 GMT -5
Here is one of my measurements. Note there are very few phase changes at the mlp. Mains are crossed at 80 Hz to dual subs. I use the default Dirac tilted house curve. For four subs you need a miniDSP to first time align everything. In fairness no pre/pro in this price range time aligns four subs. I do use a wye adapter from left sub out and have everything very symmetrical and calibrated for only the mlp. I was running them in groups of two. It appears you are one of the lucky ones. But try running the subs in dual mono,I'd be willing to bet you'd have a wonky response. My room is in pieces at the moment due to a projector, amplifier and subwoofer upgrade/change. I'll repost my graphs when all is put back together. I don't doubt what yiu are saying, but it is highly unlikely that I will want to mess up my perfectly tuned system.
I just used a wye adapter since it is recommended over and over here and on the AVS thread.
Dirac does not set phase and level independently for each sub prior to applying EQ when using dual sub mono outputs (like Audyssey XT32 SubEQ HT would), so it makes the most sense to use a wye adapter if the subs, distances and levels are the same (unless the room is really unsymmetrical then you'd want an external DSP to set phase and level for each sub independently and connect this to a single sub output on the XMC). |
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Mar 8, 2016 14:14:06 GMT -5
I was running them in groups of two. It appears you are one of the lucky ones. But try running the subs in dual mono,I'd be willing to bet you'd have a wonky response. My room is in pieces at the moment due to a projector, amplifier and subwoofer upgrade/change. I'll repost my graphs when all is put back together. I don't doubt what yiu are saying, but it is highly unlikely that I will want to mess up my perfectly tuned system. I just used a wye adapter since it is recommended over and over here and on the AVS thread. Dirac does not set phase and level independently for each sub prior to applying EQ when using dual sub mono outputs (like Audyssey XT32 SubEQ HT would), so it makes the most sense to use a wye adapter if the subs, distances and levels are the same (unless the room is really unsymmetrical then you'd want an external DSP to set phase and level for each sub independently and connect this to a single sub output on the XMC). We are 100%on the same page...I just haven't been as lucky with my subs being matched to my mains. The jl subs only extend to 20hz ? That's good to know.. |
|
|
|
Post by etc6849 on Mar 8, 2016 18:27:39 GMT -5
That's what Dirac did initially. I added some more OC 703 bass traps (8 more 4" thick panels) and have reran dirac since my other post in the dirac thread. -3dB point this time was better automatically (not sure why), but it was at the expense of decay times. May have had the JL F212's high pass filters engaged for purple plot, but don't think so. I think the first time Dirac did a better job by not boosting below 20Hz, but with the extra treatments, it does boost these frequencies. Presumeably because there are more filters that are available after better treating 80Hz and up, but I'm not sure... I'm probably going to leave it like it is though as the lower extension is better for movies, but really the waterfall plot decay times are far more important than what a -3dB point is. I can tell you that sealed subs are awesome after using the JL F212's for a few months. Came from PB13 ultras before. These JL F212's are the most musical subs I've heard in my room. BEFORE:  AFTER:   We are 100%on the same page...I just haven't been as lucky with my subs being matched to my mains. The jl subs only extend to 20hz ? That's good to know.. Attachments:
|
|
