Tackling the toughest room tomorrow, the "Greatroom"

[3dbinCanada]

The fun is about to start. Ive purchased a second identical PSB Subsonic6 used and cheap, have a miniDSP and Im not afraid to use either so dont get any ideas!!!!

I will start with gain matching the two subs which are placed on the outside of my main speskers at the 1/4 anc 3/4 room position on the long wall. I suspect Im going to be running a lot of measurements as the greatroom is big, open, and irregularly shaped.

 

[Sonnie]

Uh-huh... so you really think you are going to use that miniDSP... we'll see.

Timing?

 

[3dbinCanada]

Uh-huh... so you really think you are going to use that miniDSP... we'll see.

Timing?

No matter where I placed a single sub, I never got a smooth response like I was able to in the basement. Unfortunately, YPAO sucks handling the bass. I bought a 2nd sub and will now need REW to dial them in and to produce a flattened house curve for a more even in room response.

 

[Todd Anderson]

You have a pretty decent positioning under the painting (green)... and facing couch (purple). Not bad at all. Of course, you'd need to do some listening tests, but I'd probably zero in on those.

 

[Sonnie]

Multiple subs usually do the trick... especially if you have the miniDSP with all those PEQ filters to use.

 

[3dbinCanada]

What a day. I'm exhausted moving stuff around. I started today by placing the subs in the 1/4 and 3/4 position on the long wall and after calibrating the sub gains, I proceeded with the measurements. It turns out that the left LP response was horrendous. I pushed the sub to the corners of the long wall and took measurements, I had a dip in the center or main LP but it was better than the alternative. I went further with the subs in the corners r as I'm waiting for longer sub cables from Amazon to arrive and I still had to try and figure out the rest of the miniDSP REW process.

The first graph is what the individual sub responses looked like along with the combined L+R sub response;


The second graph is the combined sub responses across 3 listener positions.


The third graph shows both the raw and REW eq'd response at the main LP


The last graph is me playing with MiniDSP using input EQ to lessen that notch.

 

[3dbinCanada]

I also want to publicly thank John for all his help with my basement setup. Thanks John!! I really appreciated your patience and help.

 

[JStewart]

I also want to publicly thank John for all his help with my basement setup. Thanks John!! I really appreciated your patience and help.

It was easy, you did all the work! Thanks for letting me look at it with you.

Have fun with this project.

 

[3dbinCanada]

Did another sub placement exercise today. The right corner sub in yesterdays placement was moved to the other end of the couch, still behind it and firing back into the corner of its previous placement. The Left corner sub was moved to the right of the right speaker centered under the window. I will post measurements tomorrow.

This is where I ended up placing the two subs. Its even a smoother response than the one subs in the room corners.. Ther at opposite ends of the couch but give the best bass response where the white recliners are, I dont quite get it.


If you notice the media stand is under the TV. I used those 3M velcro strips and velcroed the miniDSP to the back of the stand.

 

[JStewart]

Ther at opposite ends of the couch but give the best bass response where the white recliners are, I dont quite get it.

Unless you have a perfectly rectangular room with perfectly reflective walls bass response is always a crap shoot!

 

[3dbinCanada]

Here are the plots. The first plot is of each sub by itself taken from the center LP and R+L subs from center position.


Time aligned but uneqed response across the 3 LP


For the EQ, I chose the slope of the bass to be +10db higher between 20 and 30 Hz and be down at 10 db at a 100 Hz based on the Youtube video stating that the lower frequencies (20-30) need to be 10 db louder than at 80 Hz, aka house curve.


I've listened to music and some BluRays and I must say that I agree with the slope philosophy, The bass is no longer boomy but the floors are rattling because of the lower bass. I'm actually quite pleased with the results.

Now integrating this with YPAO was a process I had to think about and run a few measurements. What I ended up doing was disabling the two sub outs on the miniDSP and running YPAO. I also ran YPAO for the main or center LP as I did NOT like what its was doing when I ran it across the 3 LPs. I realise that this would set the mains to large so just for shits & giggles (my favourite English expression) I ran a measurement as shown below.


I enabled the sub outputs on the MiniDSP, went into the AVR config menu, set the bass to sub only, set mains to small, and set the cross over to 90 Hz..(I experimented with that and 90 gave me the best result) . I also played with the sub distance and found that 10.5' gave me the best response. I also took a measurement of YPAO set to through which means no YPAO EQ but bass management is still employed.

 

[wus]

I enabled the sub outputs on the MiniDSP, went into the AVR config menu, set the bass to sub only, set mains to small, and set the cross over to 90 Hz..(I experimented with that and 90 gave me the best result) . I also played with the sub distance and found that 10.5' gave me the best response. I also took a measurement of YPAO set to through which means no YPAO EQ but bass management is still employed.
View attachment 40351

Looks like you're a true bass fan if you like it like this, and if this is what you really get at your listening position.

As a HiFi fan I wouldn't want this - but that's probably just me.

 

[3dbinCanada]

Looks like you're a true bass fan if you like it like this, and if this is what you really get at your listening position.

As a HiFi fan I wouldn't want this - but that's probably just me.

According to Fletcher Munson, it takes more volume to hear bass note between 20 and 30 Hz than it does between 70 and 80 db. Basically I tuned the subs to follow this contour. I can tell you first hand that the bass even for music sounds controlled and tight and far from flabby. There is no booming at all.

 

[wus]

Reading the thread here I got the impression that you invested considerable time and thought into your subwoofer setup. To be sure there are no standing waves one should look at reverberation times over frequencies (decay plot). Even if you didn't, I believe that you did a good job at minimizing them by placing the 2 woofers at suitable positions in your room and reducing remaining minor resonance frequencies by equalization based on REW's suggestion. "There is no booming at all" tells me that you succeeded in this regard.

Fletcher Munson found that humans don't hear hear low frequencies equally well as higher ones. But this is also true for all original sounds. Following the HiFi ideal - to reproduce sound the way it sounded when it was first produced (as much as possible, under the different living room conditions) - we should then not over-emphasize any frequency band (at high SPL).

Fletcher Munson also found that human's ability to hear low frequencies deminishes further and further the more sound pressure levels fall, so if you wanted to equalize for listening at, say, 60 dB, your house curve will do. But it will overdo bass if you turn up louder.

Better AV receivers have contour eq built in, so there is not need to hard-implement it into the subwoofer's response.

Of course in the end it's all a matter of taste and individual likings, so definitely go with what you found now if you like it.

 

[Sonnie]

I believe I remember reading in Floyd Toole's book that the blind testing results show that more people prefer the Harman curve, which accounts for the Fletcher Munson study. I love the bass... and I tune it for medium high to loud... as I don't listen quietly very often. Sub bass is still up 10db or so down low.

 

[CAAudiophile]

Multiple subs are best with DSP and adjustable phase .. It is all about the phase in subwoofer. In order to get a smooth bass response whether you have one sub or 4 subs, phase alignment is A MUST if not crucial. The way to do it, is to align all sub (s) to the main speakers using a frequency that is common with both the main speakers and the sub(s) (no matter where it is in the room ) i.e. find the phase angle of your main left speakers for instance at 100 HZ . It could be any frequency but the 100 HZ is common with both sub and main speakers. Dial in the phase in your sub to match the phase of the main at that frequency. Do that for all the subs and you will have a great smooth bass.

 

[3dbinCanada]

Multiple subs are best with DSP and adjustable phase .. It is all about the phase in subwoofer. In order to get a smooth bass response whether you have one sub or 4 subs, phase alignment is A MUST if not crucial. The way to do it, is to align all sub (s) to the main speakers using a frequency that is common with both the main speakers and the sub(s) (no matter where it is in the room ) i.e. find the phase angle of your main left speakers for instance at 100 HZ . It could be any frequency but the 100 HZ is common with both sub and main speakers. Dial in the phase in your sub to match the phase of the main at that frequency. Do that for all the subs and you will have a great smooth bass.

I did vary the subwoofer distance on the AVR which I believe I posted earlier and thats the best response I could get. As I understand it, varying the subwoofer distance is varying the phase response between sub and loudspeaker unless I missed something. It wouldn't be my first time missing something either.

 

[CAAudiophile]

Indeed, you are right about the distance and phase response however, if you could match the phase of your main speaker at a given frequency say 100 HZ to that of the sub phase ( adjust the phase of the sub equal to the phase of the main at the 100 HZ) at that frequency then you get the best bass.

 

[3dbinCanada]

I have only 0 and 180 degrees toggle switch on the sub for phase control so I think Im limited in my phase matching capability.

 

[JStewart]

I have only 0 and 180 degrees toggle switch on the sub for phase control so I think Im limited in my phase matching capability.

Changing distance/delay changes the phase alignment between sub and mains too. If out of phase there is a strong dip centered at the XO. Your chart doesn’t show that so looks like your good to go already.

 

[3dbinCanada]

I retook some measurements in the great room again but this time the microphone head was at least a couple of inches above the back of the chair. This sure helped smooth things out. I did the same thing for my basement as well. I will post the results there.

 

[3dbinCanada]

I decided to swap in the PSB500 and swap out the PSB600. I found some stands for the 500s and the tweeters are now at ear level.


Here are the measured responses;

Subs Only measured across all 3 LP


Mains set to large subs turned off at CLP


YPAO set to flat across all 3 LP


YPAO Off, Mains Set to small across all 3 LP

 

[3dbinCanada]

I finally dialed in the 3rd sub into the Greatroom. The bass is much more even now when walking around. Still not perfect but I'm not going to invest into another sub. Here are the pics.. The last sub added is the sub on the left. The other two subs I had in their present location since March of this year. The 3rd sub is holding up the lamp.



Here is the bass response.. each response at a different listening position, NON EQ verses EQ (miniDSP). The LLP is closet to the hallway and the RLP is closted to the backwall. The couch is not considered a listening position.



Here are the full frequency sweeps across the listener positions (LP). First graph is with YPAO set to flat, second graph is YPAO turned off but using bass management, and the third graph is Pure Direct

 

[3dbinCanada]

Things are going to change sometime in the new year. I ordered a much smaller but more comfortable sofa and its matching chair to replace the sofa and chair that I have now. The current furniture is just too big for the room and since my wife (God Bless her soul) has passed away, (a year ago October) I now have the authority to make such a move. That old sofa was great for napping but it sucked for upper back support and was very uncomfortable.

 

[3dbinCanada]

I have rearranged the great room. Im getting a new smaller sofa and chair for the great room and selling off the old set. I moved an Ikea book case into the basement which freed up more space for the 3rd subwoofer. I swapped out the PSB 600s for the PSB 400s onto new to me but used stands. Here are the pics..



I have a question about the measurements and generated house curve wondering if I have to redo the measurements again. I turned the crossover on the AVR to its highest value of 200 Hz and set the fronts to small. I went into the AVR sound menu and turned off all EQ. The sub distance was still at its old value of 14 feet. I took the REW measurements and generated a house curve based on the old 14' .

This curve is the house curve measured across the 3 LP.


The next curve is full frequency sweeps without any YPAO influence and with the AVR crossover set to 80 Hz.


These measurements were taken after playing with the sub distance to reduce the notch that was happening between 90 and a 150Hz. The new sub distance that yielded the best results pictured by these traces was at 25' but the house curve generation was based on 14' . I do not like the hump found in the CLP (green curve) between 67.5 and 90ish Hz . Do I need to remeasure the CLP based on the new sub distance and generate a new house curve in REW to improve upon the in room bass response?