REW

[Wull]

I've used JRiver, processor PEQ

Using REW EQ to assign filters to be used in jRiver's PEQ. Which equaliser have you chosen in REW's drop down, 'Generic'?

 

[Conrad.]

Using REW EQ to assign filters to be used in jRiver's PEQ. Which equaliser have you chosen in REW's drop down, 'Generic'?

I think so, yes. I've tried multiple types but I've never seen REW generate anything other an a PK filter. Looking at the options, Dutch and Dutch 8c looks like a nice slimmed down filter set with a high number of filters.

A couple of tips I've found:
- If you want to be aggressive an apply more filters than REW will let you, or the target varies quite a bit, focus on a specific range and generate the filters, then focus on the next range and generate the filters for that bit, and so on. That way you can vary the flatness target, boos limits, etc, per band.
- If you want an easy way to apply a house curve just use a low shelf filter, manually create one in REW. +6dB with a 0.5Q centered on 30Hz gives a good low end slope in a single filter. I've sometimes set that as a separate filter in Jriver and then I can turn it on off - it's like a loudness button all over again!

 

[Conrad.]

Hey Conrad, apologies for the delay in my response to your last post (which was quite excellent btw). I have not yet implemented all of your suggestions from the last post, but to be fair, if I don't fully understand every detail then I tend to take my time with stuff so I don't screw it up. That means that usually I end up being the turtle and not the hare, lol. And I am glad to hear that the full frequency response looks good; I had done some acoustic treatment in the room and was curious on if I had overdone it or anything along those lines. Here are my replies to the parts of your post that I quoted above.

1. - I knew that the VNF subs would be tricky and might not measure as well as the others would, but I had hoped that with those subs it would help to smooth out the overall response and maybe gain some additional output as well. My primary goal though was to provide some really good slam and give a good TR at the seating positions since I had decided against doing butt kickers.

2. - In the connection chain that you listed, you had the AVR's sub output 2 going to input 1 in the minidsp, so I wanted to clarify - I would need to use a Y-splitter (2 female to 1 male) to combine the 2 sub outs on the AVR to have them both going into input 1 on the minidsp, correct?

3. - You are right sir, that is indeed how I was splitting the signal for the 2 sub pairs coming out from the minidsp.

4. - If I am to use a splitter for the 2 sub outputs on the AVR going to input 1 on the minidsp, would that mess with the signal being sent to the minidsp at all? And when you say the trims, I'm assuming that you mean the individual channel trims - I have 3 different ways of adjusting the the levels for the subs in my AVR (levels, trims, and sub adjustment) so I just wanted to be sure.

5. - I do like the small bump in overall output that the front center sub gives me, but to your point, I could simply adjust the sub levels to compensate so I am considering taking it out of the sub chain to flatten my response.

6. - To be honest, I'm not really sure why the subs run that hot. I try to ensure that the Dynamic EQ function is turned off in the AVR when I run my sweeps, and I did level match everything to around 75dB in the minidsp per your advice. For what its worth though, when I watch TV or movies or listen to music the bass doesn't sound too overwhelming or too intense (except on some content that was mixed to be intentionally bass heavy), but I guess that could just be my personal perception/preference.
And as far as craving the ULF bass, I'm not sure if that's what I really want or not since I'm not sure that I've ever had any real exposure to ULF capable subs in a system. So far, I am really happy with the smoothness of the bass response after all the work I had done, and it has been much more refined with your excellent contributions. I just like having a strong 'kick' or 'pop' on the bass effects in a movie when it's called for.

7. - I will take your tip on potentially changing out the 6 subs for 2 or 3 really good ones under consideration. It was a battle to get wife approval on having that many subs in the room so I don't want to revert to a smaller # of subs too quickly, lest I put myself at a disadvantage for future negotiations, lol. What led me to take the approach that I did was a combination of 2 things - budget (I got those 6 subs for under $780 in total) and a desire to get the smoothest response that I could get. So far, I feel pretty happy with how the bass is performing in the system, but who knows how I may feel down the road if I get bitten by the 'optimization bug' again, lol.

I hope you had an excellent thanksgiving holiday; that is if you celebrate it where you are located. I think I remember your post saying 'with you being in the US'. I'll be looking forward to hearing your advice again when I start trying to properly integrate my mains with the subs. Until next time, take care sir!

I think it's worth taking your time with this stuff. Once it clicks you can go fast. I like to think of it as having control of the response. Once you're making changes and the outcome is what you expect, you're on top of it and you can go faster. Even then though, skipping steps is not advised. If you make multiple changes and you don't get the outcome you predicted, you have to go back through all the steps anyway. Might as well do that first time and get it right.

1) I do the same, and my VNFs measure bad. The timings and EQ I suggested should give you good TR in the bass and mis-bass regions.

2) My mistake, typo. It should be:

AVR output 1 - minidsp input 1 - minidsp output 1 - Y splitter - front left and front right subs
AVR output 1 - minidsp input 1 - minidsp output 2 - rear sub (1.5ms delay)
AVR output 1 - minidsp input 1 - minidsp output 3 - center sub
AVR output 2 - minidsp input 2 - minidsp output 4 - Y splitter - VNF Subs (7ms delay)

4) I don't know what you mean. Does that statement change based on the correction in point 2? You should be using one output from the AVR to one input in the minidsp and the second output on the AVR to the second input in the minidsp.

And yes, I mean sub trims. My Processor has individual trims for the two sub outs, I'm assuming yours does too. If you find that the VNF subs aren't hitting enough, or too much, using that config in point 2 you can adjust the VNFs independently of the main subs.

5) You have it so you might as well use it. It's not too detrimental and it does give a nice mid-bass bump. By using more subs you can lower the overall gain which means less distortion.

6) Only you can determine this. If this sounds good to you and you're happy, great. It looks hot, but it might not sound it. Watch the opening 10/15 minutes of Overlord or Godzilla: King of the Monsters and see if that sounds too much.

7) I understand that. You're getting a decent response from $800. You'd need to spend a lot more to get better extension so maybe it's not a now thing. When you're curious though, order from somewhere with a decent returns policy, integrate a couple of big subs and see if you prefer it. You can always use the excuse "I'm reducing the number of black boxes from 6 to 2". Just don't mention that the new 2 are 4' tall!

Happy Thanksgiving!

 

[cheyneb25]

- Does that statement change based on the correction in point 2?

- You have it so you might as well use it. It's not too detrimental and it does give a nice mid-bass bump. By using more subs you can lower the overall gain which means less distortion.

- Only you can determine this. If this sounds good to you and you're happy, great. It looks hot, but it might not sound it. Watch the opening 10/15 minutes of Overlord or Godzilla: King of the Monsters and see if that sounds too much.

Hey Conrad,
I couldn't agree more with you on the 'take your time and do it right' approach, so I will try to get this all wrapped up before too long and then report back with the results. Things are slowly getting easier, so I'm pretty confident that things will start to click before too much longer. I'm pretty stoked to try out the changes to the VNF subs and play around with the TR combined with the smooth response from the other subs. I know that the 'kick/pop' that I want is possible with my subs; I've achieved it before in previous iterations, but the response back then wasn't as good as what I have now so I just need to figure out at what specific freq. and combination it was that was giving me that thump. I already have a pretty good idea of where it is and what I need to do, and I think that changing the sub distance setting in the AVR will play into it as well. When experimenting with it, I found that depending on the distance I set it to it gave either a tighter (but less intense) thump in the response or a boomier (but more intense) and fuller response. I believe that the sub distance setting ties into how the subs are integrating with the mains, I'm just not knowledgeable enough yet to understand how exactly. I will probably just have to narrow it down a little more after I implement your suggested tweaks.
Now, in response to your responses...lol.

- I had suspected you meant input 2, so thanks for clarifying that for me. And yes, based on the correction you gave to point 2, that does change things. I was just worried that combining the 2 AVR sub outputs to one input on the minidsp would mess with the signal in some negative way.

- I'm glad you feel that having that front center sub contributes more than it takes away. Since it was already there and is giving at least some benefits I didn't really want to take it out of the chain. I designed the sub layout in the room before I had a way to to measure things or align the subs, I just used what knowledge I had at the time.

- Excellent movie selections to test out the bass . My go to demos to test things out are usually select scenes of BladeRunner 2049, Man of Steel, The Martian, and The Fifth Element. But the 2 that you suggested are top tier choices for testing (and viewing).

I guess after all of your advice I can now add 'getting help from an experienced AV member' to my thanksgiving list, lol. Cheers!

 

[Lesmor]

Looking for thoughts on locating the MLP to the center of the room length and width

I have always read that this is a no no and I normally I would be dead against it but inputting my room dimensions 20' x 17'6" x 8' in Room Sim MLP at 7' from the rear wall there is not a decent position for a good Frequency Response even with dual subs
this is confirmed with actual sweeps using REW

that said if you move the MLP to the centre of the room length and width in Room Sim it shows a predicted flat FR
So far I haven't tried this using REW to see what effect it has in reality
so I am looking for opinions from AVF members ?

 

[Jase]

@Lesmor

Worth a go. Might mean you have to tweak your other speakers in terms of toe in etc but if it ends up sounding better then it's worth the effort.

Weirdly, my system sounds good with the MLP in the middle of the room but actually has a big dip right at 50hz when measured.

A long time ago I also tried a Sub placed at the middle of a side wall and it measured very flat but sounded crap. MLP was just behind the halfway point though.

 

[Lesmor]

@Jase thanks for the reply
could be worth experimenting but moving forward could be a problem with the FL & FR speaker angles
In theory I should end up with peaks at 57Hz and 65Hz hopefully be able to EQ them down

 

[Jase]

@Jase thanks for the reply
could be worth experimenting but moving forward could be a problem with the FL & FR speaker angles
In theory I should end up with peaks at 57Hz and 65Hz hopefully be able to EQ them down

That's the drawback. You could end up compromising the rest of the system in the process. I still think it's worth a go just to see what results you get.

Is the goal to get more low end output from the Subs?

 

[Lesmor]

That's the drawback. You could end up compromising the rest of the system in the process. I still think it's worth a go just to see what results you get.

Is the goal to get more low end output from the Subs?

not so much in the low end,
actual sweeps of subs located anywhere at the front of the room show a wide dip between 26Hz to 59Hz
Adding a sub at the rear, and running REW it looks as if it fills in the dip, then running EQ returns a flat FR
but I think in reality that only hides and doesn't fix the lack of output from the front
inputting the room dimensions and MLP position into Room Sim there are no good positions for subs at the front of the room unless you move the MLP dead center

 

[Jase]

not so much in the low end,
actual sweeps of subs located anywhere at the front of the room show a wide dip between 26Hz to 59Hz
Adding a sub at the rear, and running REW it looks as if it fills in the dip, then running EQ returns a flat FR
but I think in reality that only hides and doesn't fix the lack of output from the front
inputting the room dimensions and MLP position into Room Sim there are no good positions for subs at the front of the room unless you move the MLP dead center

Can the Subs go pretty much anywhere or are you a bit limited in that respect?

In my room dual Subs up front just doesn't work at all but one at front left and the other at rear right works nicely as the dips of one are filled by the other. Also rotating both Subs so they fire across the room perpendicular to the MLP helped in terms of bass localisation.

Room Sim doesn't show any response change when they're rotated but measurements show a clear difference. That might be worth trying in your room if it's possible.

 

[Lesmor]

there are some restrictions for positioning
I usually use front right and rear left corners
once Q'd I can get a flat response but because of the poor FR at Front right have always thought that the front right sub was wasted
I have just bought some SVS subs which are not performing to the hype so I am revisiting sub and MLP positioning

 

[Jase]

there are some restrictions for positioning
I usually use front right and rear left corners
once Q'd I can get a flat response but because of the poor FR at Front right have always thought that the front right sub was wasted
I have just bought some SVS subs which are not performing to the hype so I am revisiting sub and MLP positioning

Does the rear sub fill in any dips in the front subs response or are they fighting each other? Individually mine don't look wonderful but combined and EQ'd they're much better. If their combined response looked naff I'd be a bit more concerned!

 

[Lesmor]

Does the rear sub fill in any dips in the front subs response or are they fighting each other? Individually mine don't look wonderful but combined and EQ'd they're much better. If their combined response looked naff I'd be a bit more concerned!

the rear left sub does fill in and hides the front dip
I am actually in discussion with Ed Mullen from SVS and he also picked up on the poor output caused by the dip on the front right sub
so that got me back thinking that the front sub is a waste,there is low output between the dip because of the room

when I thought more about it the rear sub isn't actually filling in the dip the rear sub it is actually masking the issue
best to post some screenshots of the subs positioned in the front corners
if you look at the second last graph you can see how the rear sub masks the hole in the front but that low output front the front sub is still there

 

[Conrad.]

That graph that shows the front and rear subs as separate traces, do you have the combined response as well?

 

[Lesmor]

That graph that shows the front and rear subs as separate traces, do you have the combined response as well?

Added
I have also added crossovers (subs EQ'd)

 

[Jase]

Have you tried front left and rear left combined as sub positions?

 

[Conrad.]

Added
I have also added crossovers (subs EQ'd)

Thanks. I think I agree, the front sub isn't really adding anything. A little bit of low end and some smoothness between 80 and 100Hz. From 28Hz up to about 75Hz the rear is doing most of the work.

Probably worth investigating other positions.

As Jase says though (and I'm sure you know) two poor responses don't matter, it's the combined response that matters. That said, two good responses would be preferred.

Is colocating an option? You can use the alignment tool to see what a duplicate of the rear sub would give you with some time alignment.

 

[Lesmor]

Have you tried front left and rear left combined as sub positions?

Wow that was along time ago
so yes I did years ago when I had Quattro stacks long before I used REW
I found this sweep using a XTZ room analyser

 

[Lesmor]

and finally for completion when I had the Arendal Sub 3's
the Front Left and Front right corners

 

[Jase]

Wow that was along time ago
so yes I did years ago when I had Quattro stacks long before I used REW
I found this sweep using a XTZ room analyser

View attachment 1412522

Wonder if it's worth trying the PB16's in those positions?

 

[Jase]

Just a thought. Can REW be used to run a sweep in real time like a Velodyne SMS-1/DD Sub or Anthems ARC Quick Measure?

If you placed a sub at your MLP then went around the room with the mic to see where the best responses are it would certainly save shifting subs all around the room and measuring each time.

 

[Lesmor]

Thanks. I think I agree, the front sub isn't really adding anything. A little bit of low end and some smoothness between 80 and 100Hz. From 28Hz up to about 75Hz the rear is doing most of the work.

Probably worth investigating other positions.

As Jase says though (and I'm sure you know) two poor responses don't matter, it's the combined response that matters. That said, two good responses would be preferred.

Is colocating an option? You can use the alignment tool to see what a duplicate of the rear sub would give you with some time alignment.

Hi Conrad
I appreciate you joining in
while normally I would agree the combined response is what matters,
and as you see in the graphs once EQ'd it is very good but I am struggling to get the performance I would expect from 2 x PB16 Ultras
Ed Mullen also concurs that the front right corner is compromising the performance of my subs
interestingly Ed requested that I try co-locate the front sub beside the rear left sub
observations will be interesting

 

[Lesmor]

Wonder if it's worth trying the PB16's in those positions?

Thanks Jase
I am probably working towards trying that

 

[Lesmor]

Just a thought. Can REW be used to run a sweep in real time like a Velodyne SMS-1/DD Sub or Anthems ARC Quick Measure?

If you placed a sub at your MLP then went around the room with the mic to see where the best responses are it would certainly save shifting subs all around the room and measuring each time.

I can hardly move a 9 stone PB16 so lifting onto the MLP is a no go
Guys I am heading out,thank god I hear you say Lol
look forward to more comments will call back later

 

[Jase]

I can hardly move a 9 stone PB16 so lifting onto the MLP is a no go
Guys I am heading out,thank god I hear you say Lol
look forward to more comments will call back later

Is a bit tricky with big beasts but I wonder if just having it on the floor at the MLP would help? Then again, that means moving the sofa etc...