REW subwoofer alignment Video using MiniDSP complete walk through! - Page 19 - AVS Forum | Home Theater Discussions And Reviews
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post #541 of 607 Old 06-26-2020, 06:07 PM
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Quote:
Originally Posted by Jimmy2Shoes View Post
LOL

I know some rooms take more work than others,

Not to take anything away from @RafaelSmith but he got two new subs on the first day did a quick cal with little gain match and I knew that the sub positions were good. Now perhaps he had done the homework before hand and used REW to find those positions or just got a bit of luck. Either way he's got a great FR in little to no time and the MiniDsp hasn't even been added yet. Audyssey did a great job on the phase alignment too almost to a point of not really needing a MiniDsp other than using BEQ's and flattening out the curve a little more

For others like myself have to dig deep to get a good sub curve and really it's a battle with the room than anything else, but you can only try to get the best out of the room you dealing with

You are a kind soul
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post #542 of 607 Old 06-26-2020, 07:01 PM
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Quote:
Originally Posted by Alan P View Post
Quote:
Originally Posted by RafaelSmith View Post
Like this?


Yup! That curve is a thing of beauty!! How does it sound??
Sounds really good. I still dont have the MiniDSP so EQ from REW not applied yet.

Combo of getting lucky with locations...and room not being open or oddly shaped i think.

I am definitely pleased. Tomorrow night we doing John Wick marathon 🙂
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post #543 of 607 Old 06-27-2020, 08:00 AM
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Curious....once i get the MiniDSP how should I go about using it given that I have gotten such a good result with Audyssy.

1) Use both SUB outputs of AVR to MiniDSP then to each SUB and just use the MiniDSP to apply the correction curve...leaving current Audyssey , speaker levels, distances intact?

2 )Use single out of the SUB and go thru the whole process again with REW and MiniDSP, etc?
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post #544 of 607 Old 06-27-2020, 01:57 PM
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Quote:
Originally Posted by RafaelSmith View Post
Curious....once i get the MiniDSP how should I go about using it given that I have gotten such a good result with Audyssy.

1) Use both SUB outputs of AVR to MiniDSP then to each SUB and just use the MiniDSP to apply the correction curve...leaving current Audyssey , speaker levels, distances intact?

2 )Use single out of the SUB and go thru the whole process again with REW and MiniDSP, etc?
A timely question! I reviewed all my saved posts from pre-COVID and am in same boat as you.
I have posts from several knowledgeable forum members that for the miniDSP we definitely should use one output from the receiver sub out to the miniDSP and connect both subs to the miniDSP.

My plan (which may be similar to you) is to generate a curve with REW and load into miniDSP that is targeting a flat response. I will use my Audyssey sub distance but have Audessey off for this. Then run Audyssey with that curve in miniDSP applied which of course then Audyssey should have an easier time making response flat with the miniDSP's work. I want this so I can run Audyssey on my mids and highs and it may help my subs be even flatter.

Then I want to create a house curve in REW. I need to research how to layer a house curve on top of the prior flat REW curve. But in any event don't run Audyssey again if doing a house curve as it will make it flat.

I also may then tweak my Audyssey curve in the app for mids and highs to approximate the other speakers natural curve but not there yet.

There are much more knowledgeable members in this area than me but hope this helps.
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post #545 of 607 Old 06-27-2020, 09:27 PM
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Quote:
Originally Posted by RafaelSmith View Post
Sounds really good. I still dont have the MiniDSP so EQ from REW not applied yet.

Combo of getting lucky with locations...and room not being open or oddly shaped i think.

I am definitely pleased. Tomorrow night we doing John Wick marathon 🙂
I notice in your proposed EQ that you are using ALL TEN FILTERS in the MiniDSP. That curve should need no more than three filters MAX. Try setting the curve to 1/6th smoothing in the EQ tool, then run the EQ. You will end up with much less filters, which is always a good thing.

Here is a very good article on minimal EQ:
https://www.hometheatershack.com/thr...18/#post-55647
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post #546 of 607 Old 06-28-2020, 06:40 AM
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Quote:
Originally Posted by BJBBJB View Post
A timely question! I reviewed all my saved posts from pre-COVID and am in same boat as you.
I have posts from several knowledgeable forum members that for the miniDSP we definitely should use one output from the receiver sub out to the miniDSP and connect both subs to the miniDSP.

My plan (which may be similar to you) is to generate a curve with REW and load into miniDSP that is targeting a flat response. I will use my Audyssey sub distance but have Audessey off for this. Then run Audyssey with that curve in miniDSP applied which of course then Audyssey should have an easier time making response flat with the miniDSP's work. I want this so I can run Audyssey on my mids and highs and it may help my subs be even flatter.

Then I want to create a house curve in REW. I need to research how to layer a house curve on top of the prior flat REW curve. But in any event don't run Audyssey again if doing a house curve as it will make it flat.

I also may then tweak my Audyssey curve in the app for mids and highs to approximate the other speakers natural curve but not there yet.

There are much more knowledgeable members in this area than me but hope this helps.
BJBBJB
Currently the AVR has the SUB 1 delay at 9ft and the SUB 2 delay at 9.5ft.

I assume if i decide to use the MiniDSP...what should I set the SUB delay to...keep at 9? or reset to 0 and redo delays using MiniDSP/REW?

To be honest...it sounds so good...I am afraid to start mesing with it LOL.. But I do have this nice MiniDSP...=P
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post #547 of 607 Old 06-28-2020, 11:38 AM
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Quote:
Originally Posted by Alan P View Post
I notice in your proposed EQ that you are using ALL TEN FILTERS in the MiniDSP. That curve should need no more than three filters MAX. Try setting the curve to 1/6th smoothing in the EQ tool, then run the EQ. You will end up with much less filters, which is always a good thing.

Here is a very good article on minimal EQ:
https://www.hometheatershack.com/thr...18/#post-55647
Thank you for sharing this article @Alan P. Great information and really insightful.

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post #548 of 607 Old 06-28-2020, 12:02 PM
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Quote:
Originally Posted by RafaelSmith View Post
Currently the AVR has the SUB 1 delay at 9ft and the SUB 2 delay at 9.5ft.

I assume if i decide to use the MiniDSP...what should I set the SUB delay to...keep at 9? or reset to 0 and redo delays using MiniDSP/REW?

To be honest...it sounds so good...I am afraid to start mesing with it LOL.. But I do have this nice MiniDSP...=P
Austin Jerry has a great guide

https://www.dropbox.com/s/w7jmpozner...%20Version.pdf

Step 6 explains how you can use Audyssey sub distances and convert them for use with the MiniDsp

You subs are pretty much equal distance to the MLP so you shouldn't have to much trouble
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post #549 of 607 Old 06-28-2020, 12:16 PM
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Quote:
Originally Posted by RafaelSmith View Post
Quote:
Originally Posted by BJBBJB View Post
A timely question! I reviewed all my saved posts from pre-COVID and am in same boat as you.
I have posts from several knowledgeable forum members that for the miniDSP we definitely should use one output from the receiver sub out to the miniDSP and connect both subs to the miniDSP.

My plan (which may be similar to you) is to generate a curve with REW and load into miniDSP that is targeting a flat response. I will use my Audyssey sub distance but have Audessey off for this. Then run Audyssey with that curve in miniDSP applied which of course then Audyssey should have an easier time making response flat with the miniDSP's work. I want this so I can run Audyssey on my mids and highs and it may help my subs be even flatter.

Then I want to create a house curve in REW. I need to research how to layer a house curve on top of the prior flat REW curve. But in any event don't run Audyssey again if doing a house curve as it will make it flat.

I also may then tweak my Audyssey curve in the app for mids and highs to approximate the other speakers natural curve but not there yet.

There are much more knowledgeable members in this area than me but hope this helps.
BJBBJB
Currently the AVR has the SUB 1 delay at 9ft and the SUB 2 delay at 9.5ft.

I assume if i decide to use the MiniDSP...what should I set the SUB delay to...keep at 9? or reset to 0 and redo delays using MiniDSP/REW?

To be honest...it sounds so good...I am afraid to start mesing with it LOL.. But I do have this nice MiniDSP...=P
100% agree with @Jimmy2Shoes below. Use @AustinJerry guide, that is what I plan to do.
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post #550 of 607 Old 06-29-2020, 10:33 AM
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Quote:
Originally Posted by Jimmy2Shoes View Post
Austin Jerry has a great guide

https://www.dropbox.com/s/w7jmpozner...%20Version.pdf

Step 6 explains how you can use Audyssey sub distances and convert them for use with the MiniDsp

You subs are pretty much equal distance to the MLP so you shouldn't have to much trouble
Perfect....that was very useful.

Received the MiniDSP yesterday.

Before hooking up MiniDSP wanted to do another quick measurement with my current Audyssey'd setup to save off....but for some reason I am back to showing a massive null dip around 100-130hz. So either my really good measurement the other day was fluke or I screwed something up. I know the mic is in the same position. Far as I can tell everything is as it should be with speaker settings.

I think this week when I have time I am gonna start over from scratch.....and document better what i change cause I kinda lost track just playing around.

I still have not been able to get a pc/laptop that lets me use ASIO. I really do not want to lug my big tower into HT just for this....

Any recommendations for really cheap laptop/minipc,etc that would do the trick(i.e work support multi-channel out, work with ASIO,etc)?

Might end up using it for other "PC" things in the HT.

Besides only seemingly being able to do 2 channel....the Microsoft Go tablet I have has worked great for REW and the MiniDSP plugin....kinda sucks it can't do the audio since it would be perfect for this. My guess is because it only has a single USB-C port to which I plug in a docker ..which has standard usb ports and HDMI.

Last edited by RafaelSmith; 06-29-2020 at 10:54 AM.
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post #551 of 607 Old 06-29-2020, 11:29 AM
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Originally Posted by RafaelSmith View Post
I still have not been able to get a pc/laptop that lets me use ASIO.

Try FlexASIO instead.
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post #552 of 607 Old 06-29-2020, 11:29 AM
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Alignment and Room Correction Issues

I've been working a lot with my subs in their new locations; Front Left and Back Right of the room. They are both about the 1/4 mark from the sides. I did pull them away from the wall as I was able to get a correction in some regions, so the front is 10" and the back is 24" out from the wall. The subs are gain-matched and sweeps have all been done at the MLP, which is in the middle of our 7' couch. The Umik-1 and ARC mic are always 24" away from the wall and 24" up from the cushion. Also, I haven't touched the manual PEQ on the input.

Alignment Issues
My best combined response happens when I follow the video's advice of finding the best combined response by adding delay to the output of the sub closest to the mic. I think I settled at 11.25ms (don't have measures in front of me). However, using Acoustic Timing Reference, and the Alignment Tool, they are time aligned at closer to 5ms. When I do sweeps with a 5ms delay on the rear sub instead of 11.25ms, I get big nulls. I can upload some photos later for reference if necessary.

Is there someone that can explain why this is happening? I've proceeding with where I get the best response. However, I am going to be aligning my subs to my mains once I'm totally done with ARC, and I want to make sure I'm not going to be causing any issues.

EDIT: I'm wondering if the delay doesn't matter since they are working as a "single" sub once everything is measured since they are on the same input.

ARC Issues
ARC did an amazing job when I only had one sub, and when I had dual subs without a miniDSP. However, I've had issues with it's "Target Curve" that can't be adjusted to flat in order to accommodate what I've already created in the Auto PEQ on the miniDSP. Even with no Deep Bass Boost (feature to help create more of a curve) used ARC doesn't seem to follow it's intended target. I'v feeding it really beautiful responses. Note: I am remeasuring all 5 positions at the MLP and the curve looks nearly identical to what REW shows when using the Umik-1.

ARC allows me to adjust the minimum correction frequency up to 80Hz. I have used different variations of it from 60 - 80Hz, but I still get whacky results. Luckily, I was able to get one I really like. I ended up turning on the Rumble Filter (Rythmik option), which is recommended to be kept on during room correction. This basically lowers the really low end frequencies. It worked really well. I am still tweaking with it though.

Are there any suggestions as to how I can work with my room correction better? I know it goes against all recommendations I've seen, but has anyone ever just run room correction first, then use REW? The reason I ask is that maybe I can just get ARC to set it's arbitrary curve, then I can work with what's there in REW.

I am going to be posting on the Genesis thread about a few other issues I've been having that are more Anthem related. One is about how it keeps changing my 80Hz subwoofer crossover to 120Hz for LFE during the upload process. If I change it in the receiver settings, I get a 2-4dB drop from 65 - 80Hz. I'm wondering if it's done for a smoother roll-off.

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post #553 of 607 Old 06-29-2020, 03:54 PM
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Running subs purposely out of alignment for more TR?

So, I did a thing.....

I decided to adjust delay on one of my subs (dual PSA TV42s) to try to get the flattest FR I could pre-Audyssey (per the OP's video). Previously, I had always relied on the Impulse Response graph to time align.

Here is my raw response (no EQ, no Audyssey, no delay). This response requires 4 PEQ filters in the MiniDSP pre-Audyssey:



Post Audyssey/MiniDSP:




Then I started over and adjusted delay on one of the subs to come up with this FR. This response only needed a single PEQ fillter:



And, post Audyssey/MiniDSP using the delay:



A comparison of both methodologies post Audyssey/MiniDSP:




And here is the Impulse Response with the same delay on one of the subs. It is absolutely atrocious!!




While looking at the Impulse Response makes my OCD kick in BIG TIME, there is no denying that my Tactile Response has increased at least three-fold. The TR is just ridiculous now!

As you can see, the final frequency responses are not that different...in fact, the one using the delay is a bit lower overall, but it feels waaaaay more powerful. I would say that both responses sound essentially the same, at least to my ears.

I have read of folks purposely running ported subs out of phase to increase TR and I fooled around a bit with it when I had sealed subs and a small, ported MBM. So far, I don't see a downside...well, except for that Impulse Response graph that I can't un-see, and the various new rattles I now have to chase down in my room.

One last thing, I am not getting positive summation AT ALL using this method. Here's a comparison of both methods pre-Audyssey/MiniDSP:




Thoughts?
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post #554 of 607 Old 06-29-2020, 04:39 PM
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That is very interesting @Alan P . The no delay is very interesting, and worth hooking up the laptop to follow Alice down the hole....
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post #555 of 607 Old 06-29-2020, 04:40 PM
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Quote:
Originally Posted by Alan P View Post
As you can see, the final frequency responses are not that different...in fact, the one using the delay is a bit lower overall, but it feels waaaaay more powerful. I would say that both responses sound essentially the same, at least to my ears.

I have read of folks purposely running ported subs out of phase to increase TR and I fooled around a bit with it when I had sealed subs and a small, ported MBM. So far, I don't see a downside...well, except for that Impulse Response graph that I can't un-see, and the various new rattles I now have to chase down in my room.

One last thing, I am not getting positive summation AT ALL using this method. Here's a comparison of both methods pre-Audyssey/MiniDSP:
Thoughts?
Thanks for doing this. I'm going to do the same so that I can show you the results. Based on the HTS article you shared the other day, it seems that small a jagged curve can sound very similar (just as good according to the writer) to one that is super smooth.
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post #556 of 607 Old 06-29-2020, 05:01 PM
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Alan P, I believe you're familiar with Rythmik's so you know there are lots of tweaks that can be done with one measure. This is what I currently have with ARC on.

Edit: For those that aren't familiar with Rythmik Subs, there are a lot of settings that can be done just by the flip of a switch. Three of these responses (named "3rd EQ") from the two pictures are using the same ARC profile that was uploaded.
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post #557 of 607 Old 06-29-2020, 07:11 PM
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So put the MiniDSP in the loop. Did not have much time so I started with doing the "delay" adjustment but since my subs are pretty much equal distance it ended up w/o any delays. So I did a quick Audyssey run now with just the SUB1 out of the AVR. Did a quick EQ in REW and imported into the MiniDSP. I was just wanting to see how it worked and if I could get it all done. This is what I ended up with. RED is before MiniDSP EQ applied....the other is after importing the filters into the MiniDSP for both Out1 and Out2.

I really need to find a block of several hours so I can do everything correctly. Not sure what to do about dips at ~140 and ~180.
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post #558 of 607 Old 06-29-2020, 10:28 PM
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Quote:
Originally Posted by Alan P View Post
While looking at the Impulse Response makes my OCD kick in BIG TIME, there is no denying that my Tactile Response has increased at least three-fold. The TR is just ridiculous now!

It just goes to show Alan, a pretty graph isn't always the best.
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post #559 of 607 Old 06-29-2020, 10:54 PM
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Quote:
Originally Posted by Alan P View Post
So, I did a thing.....

I decided to adjust delay on one of my subs (dual PSA TV42s) to try to get the flattest FR I could pre-Audyssey (per the OP's video). Previously, I had always relied on the Impulse Response graph to time align.

Here is my raw response (no EQ, no Audyssey, no delay). This response requires 4 PEQ filters in the MiniDSP pre-Audyssey:



Post Audyssey/MiniDSP:




Then I started over and adjusted delay on one of the subs to come up with this FR. This response only needed a single PEQ fillter:



And, post Audyssey/MiniDSP using the delay:



A comparison of both methodologies post Audyssey/MiniDSP:




And here is the Impulse Response with the same delay on one of the subs. It is absolutely atrocious!!




While looking at the Impulse Response makes my OCD kick in BIG TIME, there is no denying that my Tactile Response has increased at least three-fold. The TR is just ridiculous now!

As you can see, the final frequency responses are not that different...in fact, the one using the delay is a bit lower overall, but it feels waaaaay more powerful. I would say that both responses sound essentially the same, at least to my ears.

I have read of folks purposely running ported subs out of phase to increase TR and I fooled around a bit with it when I had sealed subs and a small, ported MBM. So far, I don't see a downside...well, except for that Impulse Response graph that I can't un-see, and the various new rattles I now have to chase down in my room. [IMG class=inlineimg]/forum/images/smilies/biggrin.gif[/IMG]

One last thing, I am not getting positive summation AT ALL using this method. Here's a comparison of both methods pre-Audyssey/MiniDSP:




Thoughts?
The idea with impulse responses is to have them start at the same time. Not to have them exactly at their peaks as alot of people do. Hope that makes sense. Try above with reverse polarity and positive polarity (0° & 180° phase).
Something to look at is the phase traces, if at the xover there is 90° + it's worth reversing the phase. The idea is to get good summation around the xover region e.g xover 80hz good summation from 40hz - 160hz.

Last edited by Philips752; 06-29-2020 at 11:36 PM.
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post #560 of 607 Old 06-30-2020, 08:49 AM
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Originally Posted by Philips752 View Post
The idea with impulse responses is to have them start at the same time. Not to have them exactly at their peaks as alot of people do. Hope that makes sense. Try above with reverse polarity and positive polarity (0° & 180° phase).
Something to look at is the phase traces, if at the xover there is 90° + it's worth reversing the phase. The idea is to get good summation around the xover region e.g xover 80hz good summation from 40hz - 160hz.
Thanks for the reply!

I am aware that the Impulses are supposed to start at the same time...this is why I am so offended by the above.

Here is a graph of subs+center with the phase plotted. To be honest, I have never looked at the phase plot very closely so I am not that familiar with it. I do see that there are no obvious anomalies in the FR or the phase around the crossover (80Hz). The phase does seem to flip-flop a bit right above the crossover though.





Here is the subs+center phase with the subs time-aligned via Impulse. The phase seems to "flip" around 100Hz, but no "flop".





Yesterday I ordered a new Blue Jeans cable so I can run my dual subs separately from the MiniDSP. I am currently just using the Delay knob on the Speaker Power amp of one sub to add the delay. Once I get the new cable I will be able to have better control over delay/polarity and will dive deeper into this.
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post #561 of 607 Old 06-30-2020, 08:56 AM
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Originally Posted by RafaelSmith View Post
So put the MiniDSP in the loop. Did not have much time so I started with doing the "delay" adjustment but since my subs are pretty much equal distance it ended up w/o any delays. So I did a quick Audyssey run now with just the SUB1 out of the AVR. Did a quick EQ in REW and imported into the MiniDSP. I was just wanting to see how it worked and if I could get it all done. This is what I ended up with. RED is before MiniDSP EQ applied....the other is after importing the filters into the MiniDSP for both Out1 and Out2.

I really need to find a block of several hours so I can do everything correctly.
Your EQ'ed response is very flat (+/-3dB from 100Hz-10Hz) and looks very good! However, most people prefer a gradually rising response under 100Hz (Harman Curve, Equal Loudness Contour). You should try adding a "House Curve" on top of your current EQ filters. If you have a single filter left on the Outputs, you can put it there. If not, you can use the Input side.

Try this to start: LS, +6dB, 30Hz, Q 0.2.


Quote:
Not sure what to do about dips at ~140 and ~180.
1/6th smoothing.

Seriously, 1/6th will more accurately represent what you actually hear. Those dips are fairly narrow and you will probably never notice them during actual content.

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Originally Posted by Alan P View Post
Your EQ'ed response is very flat (+/-3dB from 100Hz-10Hz) and looks very good! However, most people prefer a gradually rising response under 100Hz (Harman Curve, Equal Loudness Contour). You should try adding a "House Curve" on top of your current EQ filters. If you have a single filter left on the Outputs, you can put it there. If not, you can use the Input side.

Try this to start: LS, +6dB, 30Hz, Q 0.2.




1/6th smoothing.

Seriously, 1/6th will more accurately represent what you actually hear. Those dips are fairly narrow and you will probably never notice them during actual content.
Thanks will give it go.
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post #563 of 607 Old 06-30-2020, 10:12 AM
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Originally Posted by Alan P View Post
Your EQ'ed response is very flat (+/-3dB from 100Hz-10Hz) and looks very good! However, most people prefer a gradually rising response under 100Hz (Harman Curve, Equal Loudness Contour). You should try adding a "House Curve" on top of your current EQ filters. If you have a single filter left on the Outputs, you can put it there. If not, you can use the Input side.

Try this to start: LS, +6dB, 30Hz, Q 0.2.




1/6th smoothing.

Seriously, 1/6th will more accurately represent what you actually hear. Those dips are fairly narrow and you will probably never notice them during actual content.
So bored at work and since I have copy of my measurements from last night decided to play around in REW....and using the OP's video as guide for applying house curve.

I think I am on the right track?
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Originally Posted by RafaelSmith View Post
So bored at work and since I have copy of my measurements from last night decided to play around in REW....and using the OP's video as guide for applying house curve.

I think I am on the right track?
That'll work! After you give it a listen, you might want to increase/decrease the slope to tailor it to you personal preference. So easy to do with REW + MiniDSP.

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That'll work! After you give it a listen, you might want to increase/decrease the slope to tailor it to you personal preference. So easy to do with REW + MiniDSP.
House Curve EQ applied.. Time for some listening tests
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Quote:
Originally Posted by Alan P View Post
Quote:
Originally Posted by Philips752 View Post
The idea with impulse responses is to have them start at the same time. Not to have them exactly at their peaks as alot of people do. Hope that makes sense. Try above with reverse polarity and positive polarity (0° & 180° phase).
Something to look at is the phase traces, if at the xover there is 90° + it's worth reversing the phase. The idea is to get good summation around the xover region e.g xover 80hz good summation from 40hz - 160hz.
Thanks for the reply!

I am aware that the Impulses are supposed to start at the same time...this is why I am so offended by the above. [IMG class=inlineimg]/forum/images/smilies/biggrin.gif[/IMG]

Here is a graph of subs+center with the phase plotted. To be honest, I have never looked at the phase plot very closely so I am not that familiar with it. I do see that there are no obvious anomalies in the FR or the phase around the crossover (80Hz). The phase does seem to flip-flop a bit right above the crossover though.





Here is the subs+center phase with the subs time-aligned via Impulse. The phase seems to "flip" around 100Hz, but no "flop". [IMG class=inlineimg]/forum/images/smilies/smile.gif[/IMG]





Yesterday I ordered a new Blue Jeans cable so I can run my dual subs separately from the MiniDSP. I am currently just using the Delay knob on the Speaker Power amp of one sub to add the delay. Once I get the new cable I will be able to have better control over delay/polarity and will dive deeper into this. [IMG class=inlineimg]/forum/images/smilies/biggrin.gif[/IMG]
No worries.

I just got some Blue Jeans Cable as well 40ft for the rear sub. I have always had the subs between the two mains. Currently left one still inside left main, now the right one has gone behind the couch located diagonally not quite the same distance from the other wall. I'm going to try to creep it over gradually so not so noticeable from other half 😁

Loopback or acoustic timing must be active for all measurements.
Measure all measurements 10-20,000hz including subs with your current settings e. g 80hz xover.

With your setup:
Left main (only)
Right main (only)
Sub 1
Sub 2
Use either main as your acoustic timing channel.
Can use Arithmetic to combine both mains if need to.

You are time aligning with a main or centre, not the other sub. The reference requires a full range speaker.
Go to tab "All Spl" for overlay of the phase graphs.
The flip flops is the room, if you change the smoothing to 1/6 or 1/12 or even 1/3 this will smooth the phase traces. This will make it easier to understand.
There is almost always more than one delay setting.

Instead of me burbling on do you want to post the graphs based on above measurements and I will try to help.

In the "All Spl" tab please tick just the main and one of the subs and on second graph same main and other sub.
Also scale the graph according to your xover, if 80hz scale 30-200hz.

Please attach them, hard to see on phone only at the moment.

Last edited by Philips752; 07-02-2020 at 12:05 AM.
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post #567 of 607 Old 07-01-2020, 01:43 PM
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Quote:
Originally Posted by Philips752 View Post
No worries.

I just got some Blue Jeans Cable as well 40ft for the rear sub. I have always had the subs between the two mains. Currently left one still inside left main, now the right one has gone behind the couch located diagonally not quite the same distance from the other wall. I'm going to try to creep it over gradually so not so noticeable from other half 😁

Loopback or acoustic timing must be active for all measurements.
Measure all measurements 10-20,000hz including subs with your current settings e. g 80hz xover.

With your setup:
Left main (only)
Sub 1
Sub 2
Use either main as your acoustic timing channel.
Can use Arithmetic to combine both mains if need to.

You are time aligning with a main or centre, not the other sub. The reference requires a full range speaker.
Go to tab "All Spl" for overlay of the phase graphs.
The flip flops is the room, if you change the smoothing to 1/6 or 1/12 or even 1/3 this will smooth the phase traces. This will make it easier to understand.
There is almost always more than one delay setting.

Instead of me burbling on do you want to post the graphs based on above measurements and I will try to help.

In the "All Spl" tab please tick just the main and one of the subs and on second graph same main and other sub.
Also scale the graph according to your xover, if 80hz scale 30-200hz.

Please attach them, hard to see on phone only at the moment.
I have always used the timing reference for all measurements...well, since it became available in REW, that is. AFAIK, it does not matter which of the satellite speakers you use for timing reference (I use my right surround speaker).

I am very familiar with time-aligning the sub(s) to the center/mains (aka Sub Distance Tweak). However, the subs should be time-aligned with each other before performing the SDT. In my experiment above, I purposely ignored the horrid sub-to-sub time-alignment, but I still aligned subs to center afterward.

AFAIK, you cannot view the phase plot while using the All SPL tab....is there a trick that I don't know about?

You are correct though, when I apply smoothing to the graphs the flip-flops in the phase plot are reduced dramatically.

My previous graphs were attached to the posts (as well as inserted into the body of the post).


Just as a point of reference; the problems with my raw subwoofer response can be directly attributed to my lack of placement options. These are VERY large subs and the preferred place for them aesthetically (and for that nearfield TR!) is directly behind my seating. With the subs in the back of the room, I have that large suck-out at 60Hz. This experiment allowed me to eliminate that dip pre-Audyssey with the added bonus of less PEQ done by the MiniDSP and increased TR. A win-win-win...except for the fact that the subs aren't "properly" time-aligned.

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Quote:
Originally Posted by Alan P View Post
Quote:
Originally Posted by Philips752 View Post
No worries.

I just got some Blue Jeans Cable as well 40ft for the rear sub. I have always had the subs between the two mains. Currently left one still inside left main, now the right one has gone behind the couch located diagonally not quite the same distance from the other wall. I'm going to try to creep it over gradually so not so noticeable from other half 😁

Loopback or acoustic timing must be active for all measurements.
Measure all measurements 10-20,000hz including subs with your current settings e. g 80hz xover.

With your setup:
Left main (only)
Sub 1
Sub 2
Use either main as your acoustic timing channel.
Can use Arithmetic to combine both mains if need to.

You are time aligning with a main or centre, not the other sub. The reference requires a full range speaker.
Go to tab "All Spl" for overlay of the phase graphs.
The flip flops is the room, if you change the smoothing to 1/6 or 1/12 or even 1/3 this will smooth the phase traces. This will make it easier to understand.
There is almost always more than one delay setting.

Instead of me burbling on do you want to post the graphs based on above measurements and I will try to help.

In the "All Spl" tab please tick just the main and one of the subs and on second graph same main and other sub.
Also scale the graph according to your xover, if 80hz scale 30-200hz.

Please attach them, hard to see on phone only at the moment.
I have always used the timing reference for all measurements...well, since it became available in REW, that is. AFAIK, it does not matter which of the satellite speakers you use for timing reference (I use my right surround speaker).

I am very familiar with time-aligning the sub(s) to the center/mains (aka Sub Distance Tweak). However, the subs should be time-aligned with each other before performing the SDT. In my experiment above, I purposely ignored the horrid sub-to-sub time-alignment, but I still aligned subs to center afterward. [IMG class=inlineimg]/forum/images/smilies/wink.gif[/IMG]

AFAIK, you cannot view the phase plot while using the All SPL tab....is there a trick that I don't know about?

You are correct though, when I apply smoothing to the graphs the flip-flops in the phase plot are reduced dramatically.

My previous graphs were attached to the posts (as well as inserted into the body of the post). [IMG class=inlineimg]/forum/images/smilies/wink.gif[/IMG]


Just as a point of reference; the problems with my raw subwoofer response can be directly attributed to my lack of placement options. These are VERY large subs and the preferred place for them aesthetically (and for that nearfield TR!) is directly behind my seating. With the subs in the back of the room, I have that large suck-out at 60Hz. This experiment allowed me to eliminate that dip pre-Audyssey with the added bonus of less PEQ done by the MiniDSP and increased TR. A win-win-win...except for the fact that the subs aren't "properly" time-aligned. [IMG class=inlineimg]/forum/images/smilies/redface.gif[/IMG]
Funny you talk about a 60hz suck out I have a bit of a dip at 60ish hz in the rear sub. If I move about 6 inches it starts to improve as I get closer to the wall, but it's ideal place is guess we're well unless I feel like stepping over a sub everytime walk into the lounge.
Left out Right main only in the list of measurements.
"All Spl" > Controls (top right) > Alignment Tool > phase overlay. You would have been in this window before.
Attached and inserted was what exactly is needed to see on the phone.
I can't say I have heard of a surround speaker as a reference.
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post #569 of 607 Old 07-02-2020, 07:28 AM
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I have spent some time digesting some of the helpful videos available on the web, but like a lot of beginners, I would appreciate some feedback on my results. I am using the miniDSP 2x4 HD with the Umik-1 microphone.

I have a dedicated room that is 20 ft x 23 ft with an overall ceiling height of about 12 feet. The walls slope inward starting about 4 feet from the ground because this is a “bonus” room directly over the garage. There are three subwoofers in the room. Two are located in the front of the room (left corner and 1/4 room width from right wall) and one in the back left corner.

Here are my questions:
1) how does the attached graph look? I am mostly concerned about the Null at 70Hz.
2) can someone recommend a video that focuses more on creating the house curve with REW? I used video 7 from Home theater guru but it was difficult to read all the numbers on the screen and my REW software seems to have slightly different filter choices.
3) how can if force REW to y axis values as multiples of 5? It defaulted to 10 and I only saw 5 when I started stretching the graph size. R
Isn’t there a menu option to control this value?
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post #570 of 607 Old 07-02-2020, 09:15 AM
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I have spent some time digesting some of the helpful videos available on the web, but like a lot of beginners, I would appreciate some feedback on my results. I am using the miniDSP 2x4 HD with the Umik-1 microphone.

I have a dedicated room that is 20 ft x 23 ft with an overall ceiling height of about 12 feet. The walls slope inward starting about 4 feet from the ground because this is a “bonus” room directly over the garage. There are three subwoofers in the room. Two are located in the front of the room (left corner and 1/4 room width from right wall) and one in the back left corner.

Here are my questions:
1) how does the attached graph look? I am mostly concerned about the Null at 70Hz.
2) can someone recommend a video that focuses more on creating the house curve with REW? I used video 7 from Home theater guru but it was difficult to read all the numbers on the screen and my REW software seems to have slightly different filter choices.
3) how can if force REW to y axis values as multiples of 5? It defaulted to 10 and I only saw 5 when I started stretching the graph size. R
Isn’t there a menu option to control this value?
That null near xover? I kept having a null near where my xover was at...I would change xover and the null would move accordingly. Turned out to be phase switch setting on the subs....i think....at least it removed the null at the xover but now I have dips beyond the 120hz range.

As for guides....I watched the video 7 about 10 times and while it was very useful....I found it too "advanced" for me in the sense that I literally have no choice for sub placement...beyond moving them a few inches forward and back. And the video seemed to assume a perfect setup or at least the ability to spend time adjusting things like sub placement and such. I played around with using invert on MiniDSP, putting in delays but it just made things worse...measurement wise....although I admit I was not really sure what I was doing or how to know if I was getting better or worse...depending on how I looked it the answer was different =P I felt like I was throwing darts with my eyes closed.

My graphs look ok to me in the 15-120hz range but are all over the place beyond that (big dips, massive loss of overall output starting at 100hz)...and I have tried all I can think of to fix it but just end up frustrated. I think I am done with it for now...until I can understand better what I can and cannot control given my setup. One thing I am starting to think is that I did not need to go dual subs....since the response for each of my subs are essentially dentical....I cannot seem to get the "helping eachother" at peaks and dips differences the video mentions. If I understand things correctly....unless I can freely position subs in the room where they need to be...that is not gonna change.


Maybe in a week or two ...I will attempt to start over from scratch and maybe take more "baby" steps. I think i just overwhelmed myself.
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