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Hi,

First, I think it's a good call to believe that Audyssey can reduce your overall headroom somewhat, depending on how much it is pulling-up dips, compared to pulling down peaks. Audyssey attempts to compensate for that by allowing its software to pull-down peaks by up to 20db, but it can only pull-up dips by a maximum of 9db. Most rooms have both peaks and dips in the frequency response, so the loss of headroom from pulling-up dips, and the gain in headroom from pulling-down peaks, tends to even out. In your case, though, they may not even out, if you don't have many frequencies peaking to start with.

Second, although the graphs that you see aren't totally accurate (for instance, they only depict what Audyssey was trying to do, not what it actually did) they do indicate some issues that might be ameliorated with better subwoofer placement. Fortunately, fixing dips in the 40Hz to 80Hz range doesn't consume as much headroom, as fixing even lower dips would, but you might get better results if you experiment a bit more with sub placement and test the results with Audyssey calibrations.

Third, your volume level is pretty high. Combined with the sub boost you are using, you are putting a good bit of demand on your subs. Remember to keep your trim levels well in the negative range (say about -5) and use your sub gains to add most of your subwoofer boost, post-Audyssey. That will help to prevent clipping, which is a form of distortion, but one that might be harder to hear. Section II of the Guide explains gain/trim relationships in detail.

I definitely think that a couple of PSA V1510's would be a significant upgrade for the content and preferences you describe. The current line of PSA ported subs roll-off a little faster below 20Hz than some other subs do, but they are designed to have a lot of >25Hz SPL. I think that you would enjoy the upgrade, but remember that subwoofer placement is what causes the dips you are seeing in the before graph, and you would still want to maximize your pre-Audyssey response, even with the new subwoofers.

This is just something to experiment with. If you get serious about it, you might want to invest in a calibrated UMIK-1 and download REW. It's free, but takes a little time and effort to learn. You might, for instance, want to change the phase on one of your subs, in an effort to reduce cancellation currently occurring in the 40Hz to 80Hz range. But, I'm not sure that you will be able to do that successfully by ear, or just with an SPL meter. You can try though, by listening/measuring the volume of some test tones in that range, while adjusting the phase control on just one of your subs.

I think that trying to reduce the potentially large area of depression in your frequency response, between 40hz and 80Hz, will be helpful regardless of which subs you have, although the PSA subs will absolutely have a lot more native volume in that range than your Outlaw subs have. :)

Regards,
Mike
Not sure if it helps but at -10 MV and DEQ off i boost bass 4db in the AVR which gets me to -5.5 in AVR. I've also done the 4db boost just using the sub gain and leaving AVR at -9.5. The only difference i can notice is that doing it using the sub gain instead of AVR gives it a more robust sound.Im guessing its because the sub amp is doing more of the work that way.:)
 

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darthray, mthomas47, and drh3b, thanks for the input.

Regarding phase adjustment to reduce cancellation, I thought that SubEQ HT was supposed to set the delay optimally. If I were to adjust phase on one sub 180 degrees (these subs only have 0/180 settings) prior to Audyssey calibration, wouldn’t SubEQ HT readjust the delay based on what it’s trying to achieve?

One thing I could try is to flip 1 sub to 180 degrees phase, rerun Audyssey, and see if the before plot is any better/different.

Regarding sub positioning, I am very limited in this room.

Current sub locations are in the front of the room – orange and green circles in the first pic. Note that picture is old and right before I added the second sub. Currently, The Outlaw X-12 is in the orange circle and the Outlaw LFM-1 is in the green circle.

My only 2 other placement options are:

1) Move both subs to the side walls, somewhat near the midpoints of the room, although not perfectly symmetrical – yellow and blue circles in the second pic. Running a sub cable to the blue circle would be a pain.

2) Or, keep one sub in one of the current orange or green front positions and move the other to one of the side wall blue or yellow circles.

I do have some concern that moving the subs to the side walls, closer to the couch, could cause localization for music.

Also, the couch is about at the midpoint of the room, which I believe is also less than ideal, regardless of sub positioning.

So, it this room, I feel like I have some real sub placement limitations and compromises, so that is why I was thinking that bigger subs with more headroom, combined with SubEQ HT equalization, might be a viable upgrade path forward.
Just for info, I agree with Mike to try the other locations placement before calibration.
Since you use REQ, it is a strong advantage you got over me.
Since I try different locations, run Audyssey and go by hear.
Repeat the process, until happy with the way it sound.

You are very welcome! Let's take some of those issues one at a time. First, with respect to room modes, your couch is not actually at the midpoint of the room. Some bass will escape to the space beyond your room, but the primary room modes are determined by the four walls which enclose the space, and not by the openings to other spaces. So, your couch location is not a principle factor in the mid-bass cancellation, in my opinion. If I'm right, that's a good thing, because that's a harder thing to fix!

FWIW, I think that you will get better overall sound quality, if you move your couch about a foot away from the wall, and put a painting or something absorbent on the wall behind the couch. That will help your mid-range and treble sound quality. Reading Section I of the Guide will help you to understand why that would be helpful, and you will also see some suggestions in that section about running a better Audyssey calibration. The bare wall directly behind your couch is a factor in what you hear, and in how Audyssey performs.

Second, I would experiment with other subwoofer locations before running Audyssey, and I would experiment with changing the phase on one of the subs after running Audyssey. It is important to understand that there is a degree of trial-and-error in all of this. You observe a large area of cancellation and try different methods of fixing it, without knowing in advance whether you can find physical locations which will work better. And, you won't know whether you will have localization either, until you try the placement you mentioned. Especially, with more than one sub in a room, nearfield placement of a sub can sometimes work very well.

The same thing applies to making changes in the phase on one of the subs. You just have to experiment to see if it helps. Audyssey sets the distance for each sub separately, but it EQ's the two subs together, based on their combined response. Where you know that you have a large area of cancellation, especially in a portion of the frequency range which is very important to you, you can experiment with a phase adjustment, or a distance adjustment for that matter, to see if it helps. The suggestions I am making are not just random ones, but I still can't tell you which subwoofer locations will work best, or whether a post-Audyssey phase adjustment will be helpful. You still have to experiment to find out.

I think that having better subs with more mid-bass headroom, does represent a good path forward. But, more headroom won't, by itself, fix a null. If the null remains after your Audyssey calibration, the new subwoofers will be able to play all frequencies louder than the current ones could, but that portion of the frequency range, which dips down, will still play softer than the rest of the frequency range played by the subs.

If Audyssey is fixing the problem sufficiently that you aren't aware of any loss of SPL in the mid-bass range (40Hz to 80Hz, in this case), then more capable subwoofers will absolutely give you more of what you want, and they won't have to work as hard to do it. In that case, I think that the two PSA subwoofers would be a great choice, because they are especially strong in the range you care most about. And, I would also expect you to notice an overall improvement in your bass sound quality with better subs.

If however, there is an ongoing issue in the 40Hz to 80Hz range that you are aware of, then some experimentation may be helpful to you, either with your current subwoofers, or with the new ones. That's really all I was saying.

We all decide for ourselves how much experimentation is enough. Some people really like to tinker with subwoofer placement, and with other things including measurements, and many others just like to put subwoofers where they seem to fit and work fairly well. I think that there is no absolute right or wrong answer to any of this--just the answer that your own sense of curiosity, and/or level of satisfaction, dictates. :)

Regards,
Mike
Very well said!

While I like to experiment with locations, and AVR/Sub settings.
It come a time, when fishing in the dark for the best results.
Without a tool like the REQ. Can become a very difficult thing to do.

Since my bass sound good by hear after calibration, therefore happy.
Is there room for improvement, more likely.
But will not happen until, I understand how to use something like REQ. Due to my lack of skill for computer/laptop stuff:(


Ray
 

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Thanks Alan. Yep, I am gonna bypass (disable) PEQ for subs and re-run Audyssey. THEN I will break out REW and check on things. It will most likely be towards the weekend. My days are pretty full. Thanks for the continued assistance. Keith


I gave up using PEQ in my miniDSP 2x4-HD, now I use it only to time-align both subs, without Audyssey on, and save that setting. I’ll run Audyssey and let it set the filters. In the AVR. Once done, I’ll save another config file in slot 2 in the 2x4 with the Audyssey DynEQ AVR settings I like for a “daytime.xml” file, and load that daytime settings file again, but in slot 3 — I open the outputs side of the 2x4, and turn on the compressor (even the default compressor “on” values are pretty good), I turn down level for each sub -6dB or so, and change the low pass starting at 20Hz up to starting at 60 Hz or so. Amazing how my mind “adds” the missing bass while not messing much with the upper frequencies. Best, it does not disturb the upstairs neighbors, and I love my neighborhood, so being a good downstairs neighbor has value to me.

That setting, then I save as “nighttime.xml”

I rarely use my Denon AVR “low frequency containment” setting, since the result sounds “emasculated” compared to the miniDSP method above. (Forgive the unintended gendering implication of my word choice. )



—Thumprchgo
a.k.a., Mark, Prairiedawg, OldCrankInTheBack

Setup: Mostly plebeian, but carefully curated.
Denon AVR-X4400H, 9.2; Audyssey MultiEQ-XT32
Polk Audio RTiA series for L/C/R,
FXi series for Side Surrounds,
OMW5 for on-ceiling Atmos, at 5.2.4
Polk DSW-550 subs, two.
AppleTV 4K, Fire Stick 4K, QNAP NAS,
nanoAVR-DL (useless, don’t get me started)
MiniDSP 4x2HD for sub EQ and time-alignment
LG 55” 4K Dolby Vision
Innumerable beads of sweat
Thousands of frustrated, misspent hours
And one radiant smile just up ahead, off in the gloaming...

(Sent from my tablet)
 

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I gave up using PEQ in my miniDSP 2x4-HD, now I use it only to time-align both subs, without Audyssey on, and save that setting. I’ll run Audyssey and let it set the filters. In the AVR. Once done, I’ll save another config file in slot 2 in the 2x4 with the Audyssey DynEQ AVR settings I like for a “daytime.xml” file, and load that daytime settings file again, but in slot 3 — I open the outputs side of the 2x4, and turn on the compressor (even the default compressor “on” values are pretty good), I turn down level for each sub -6dB or so, and change the low pass starting at 20Hz up to starting at 60 Hz or so. Amazing how my mind “adds” the missing bass while not messing much with the upper frequencies. Best, it does not disturb the upstairs neighbors, and I love my neighborhood, so being a good downstairs neighbor has value to me.

I rarely use my Denon AVR “low frequency containment” setting, since the result sounds “emasculated” compared to the miniDSP method above. (Forgive the unintended gendering implication of my word choice. )

—Thumprchgo


(Sent from my tablet)
Interesting. My Dayton Audio DSP-408 does not have a compressor. Would have been a nice feature. One of the features I like with it however is the ability to use my phone via bluetooth to adjust things. I really just adjust levels, but could also adjust delay and PEQ if I wished.

I listen to alot of two channel music in my living room (where the DSP-408 is), with Audyssey, no DEQ. I find bass content varies GREATLY from record to record. I use my phone to adjust the subs outputs subjectively to get it full. Most of the time I can leave levels at the default values. But, just yesterday, I listened to TNT: Encore Live in Milano, just released. The kick drum was really hurting one of the sub drivers. This driver has a slightly rubbing voice coil and needs to be replaced (again). At any rate, I had to reduce both sub levels significantly for it not to overwhelm the rest of the music. I prefer this however, to having to crank the subs just to hear any bass at all.
 

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Interesting. My Dayton Audio DSP-408 does not have a compressor. Would have been a nice feature. One of the features I like with it however is the ability to use my phone via bluetooth to adjust things. I really just adjust levels, but could also adjust delay and PEQ if I wished.

I listen to alot of two channel music in my living room (where the DSP-408 is), with Audyssey, no DEQ. I find bass content varies GREATLY from record to record. I use my phone to adjust the subs outputs subjectively to get it full. Most of the time I can leave levels at the default values. But, just yesterday, I listened to TNT: Encore Live in Milano, just released. The kick drum was really hurting one of the sub drivers. This driver has a slightly rubbing voice coil and needs to be replaced (again). At any rate, I had to reduce both sub levels significantly for it not to overwhelm the rest of the music. I prefer this however, to having to crank the subs just to hear any bass at all.
Oh! Whoops, I was unclear, sorry.
I use a DSP EQ box (miniDSP 2x4HD) that sits between my Denon AVR’s two sub RCA outputs and the subs RCA inputs themselves. This box can time-align the 2 subs, (with REW, RoomEQ Wizard.)
After that calibration, then I run my AVR’s built-in Audyssey program. The little miniDSP box can load files with different parameters that only affect my subs. That’s why I have a daytime setting, and a nighttime be-considerate-of-neighbors setting. It’s the mini that has compressors that can be adjusted to kick in a certain levels and stay in until the movie quiets below a threshold I can tweak, and save as text files on my laptop.
I now have a “nervous friends” setting to use when friends who live in paper thin walled apartments come to watch a movie at my place and worry the upstairs neighbors will bang on the ceiling! I’ve lived here nine years, and it’s never been a problem in this old, brick building built more than 100 years ago.. :cool:
 

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Sub mis-match

Hoping for some advice...I recently moved and now have a more-or-less rectangular room. Front wall center is a PB-13U, back wall center is a PC12+. Hoping to use this sub arrangement to cancel the length mode peaks @ 32, 64, 96 Hz at the mlp (12' back from the front, as far as the very low frequencies are concerned).


Since I can't yet locate my calibrated SPL meter, I ran some tests using a flat signal generator and my ears. Running each sub by itself in a appx 1500 ft3 room, I find that the PB 13U has good response down to 20 Hz, while the PC12+ (all ports open & 20 Hz tuning) falls off dramatically below 25 Hz. Tried plugging one port and setting PC12+ tuning to 16 Hz, no audible change in room response, still rolls off below 25 Hz.


Should I: figure that the PB13U will "take up the slack"; start saving for a better sub to replace the PC12+; decide to live with 25 Hz as a low-end? The system is not yet set up, so I can't yet drive both subs together thru the Marantz receiver. Your thoughts would be gratefully appreciated. And thanks so much for the thread; still going through it!


Jack
 

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Hoping for some advice...I recently moved and now have a more-or-less rectangular room. Front wall center is a PB-13U, back wall center is a PC12+. Hoping to use this sub arrangement to cancel the length mode peaks @ 32, 64, 96 Hz at the mlp (12' back from the front, as far as the very low frequencies are concerned).


Since I can't yet locate my calibrated SPL meter, I ran some tests using a flat signal generator and my ears. Running each sub by itself in a appx 1500 ft3 room, I find that the PB 13U has good response down to 20 Hz, while the PC12+ (all ports open & 20 Hz tuning) falls off dramatically below 25 Hz. Tried plugging one port and setting PC12+ tuning to 16 Hz, no audible change in room response, still rolls off below 25 Hz.


Should I: figure that the PB13U will "take up the slack"; start saving for a better sub to replace the PC12+; decide to live with 25 Hz as a low-end? The system is not yet set up, so I can't yet drive both subs together thru the Marantz receiver. Your thoughts would be gratefully appreciated. And thanks so much for the thread; still going through it!


Jack
Hi Jack

How old is your Marantz AVR, and does it have a calibration system like Audyssey?
If it has Audyssey, it might show you a more truthful reading.

That said, Audyssey will do it's corrections for the lesser sub (PC12, in your case).
From my previous subs, two PB12Plus/2. I did not mind the 25Hz setting (Original tune).
With my two present PB13-Ultra, it is now set at 20Hz (also original tune).
While they go deeper, they also open a lot more vibration problems in my room.

Could I live again with a 25Hz tune, Yes. Do I like the 20Hz, also Yes.
Since I am not a person that prefer very low bass, and prefer the chest slam of the mid bass. I could live with both settings.
Just to point out, this is my preference for bass sound. And my personal opinion.

For living with a 25Hz extension. It depend on you.
To save some money, to have a better match to your present PB13. For achieving lower extension, perhaps a new (PB3000 or 4000 may work very well).
Just can't remember at this moment witch one is a better match for the PB13:(


Ray
 

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Hoping for some advice...I recently moved and now have a more-or-less rectangular room. Front wall center is a PB-13U, back wall center is a PC12+. Hoping to use this sub arrangement to cancel the length mode peaks @ 32, 64, 96 Hz at the mlp (12' back from the front, as far as the very low frequencies are concerned).

Since I can't yet locate my calibrated SPL meter, I ran some tests using a flat signal generator and my ears. Running each sub by itself in a appx 1500 ft3 room, I find that the PB 13U has good response down to 20 Hz, while the PC12+ (all ports open & 20 Hz tuning) falls off dramatically below 25 Hz. Tried plugging one port and setting PC12+ tuning to 16 Hz, no audible change in room response, still rolls off below 25 Hz.

Should I: figure that the PB13U will "take up the slack"; start saving for a better sub to replace the PC12+; decide to live with 25 Hz as a low-end? The system is not yet set up, so I can't yet drive both subs together thru the Marantz receiver. Your thoughts would be gratefully appreciated. And thanks so much for the thread; still going through it!

Jack

Hi Jack,

First of all, you are very welcome for the Guide and for the thread, and I'm glad to hear if it is helpful to you. One thing you didn't seem to mention is whether the two subs in conjunction play audibly below 25Hz? When you play both subs at the same time, does their combined sound roll-off below 25Hz, or does the PB13, in either the 20Hz mode or the 16Hz mode, still carry the <25Hz sound?

That's an important question. Intuitively, I would expect the two subs to work better together if they are both in the same 20Hz mode. The PB13 will have a slightly deeper tuning frequency than the PB12+ if they are both in the one-port extended mode. And, that may cause some cancellation below 25Hz or so.

It is possible that the position you selected for the Plus simply has a room mode that causes the sub to have cancellation below about 25Hz. You could try some other positions for that sub in hopes of finding a location where it will be able to play lower. Slightly corner-loading it, for instance might help with that. (The sub doesn't have to be pushed all the way back into a corner to benefit from some additional boundary gain. You just have to experiment.)

Sometimes, we try sub positions which should work the best, in theory, and they simply don't. Some additional placement experimentation is then required. You might also try adjusting the phase on your Plus to see if that makes any difference. That also can't be predicted in advance. But again, it is the combined sound and frequency response of the subs that you really want to concentrate on. Their individual response is not really the issue. It's how well they work together that counts. Personally, I would want to hear/feel the frequencies below 25Hz. It can make a lot of difference for 5.1 movies.

Darth's question about Audyssey was a good one. If you have a system of automated calibration and room correction built into your AVR, that may be able to help you. Ultimately, I think your best solution is to try to find another PB13 (or PC13). Ideally, you want to be able to have identical subwoofers, and if you want more low-frequency performance, the one-port extended mode would be the best way to get it. But, when two subs have different port tunes, as your current subs do, the extended mode may not be the best bet, because the different port tunes may cause some cancellation.

I think you can try to find a better location for your Plus (and perhaps try changing the phase on the Plus). You can try to replace the Plus with another PB13, or you could replace both subs with something new, such as the PB4000. I also think it's possible that you could replace the Plus with a PB4000, and get better results with the two different Ultra models. But, I'm not sure about that. I would discuss that option with Ed Mullen directly, and not just with whomever happens to answer the phone at SVS. If you email Ed, you can arrange to talk on the phone, or you can try to call him directly.

In general, identical subs work best, but the older PB13 and the newer PB4000 may be close enough to work well together. I would trust Ed's advice on that. I hope this helps! :)

Regards,
Mike
 

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Sub disparities, room resonances, etc

Thank you, Ray and Mike for your valued insights, and for all the help you've provided to us in the community.


I don't yet have my Marantz SR7011 hooked up, so cannot run both subs together just yet (nor use Audyssey MulteqXT32)...but I suspect that the PB13 will still produce strong bass to 20 Hz, and the PC12+ will not. Both are set to 20 Hz, all ports open.


Probably will be lusting for another PB13U or a PB4000 (which SVS says is the best match).


The lowest room mode for a 17' 8" length should be 32 Hz if I understand this correctly. Wanting to put the main listening position abt 3/4 back from the front wall, and take advantage of room mode cancellation per Floyd Toole's book Sound Reproduction (third edition, Chapter 8, Sec. 8.2.6). If that arrangement of subs being located center of front and back walls doesn't help much, then I'll be free to try other sub locations. Hoping to let Audyssey XT32 deal with other room modes, at least up to the transition frequency.


Which brings up another question, semi-off-topic: my receiver is compatible with Audyssey smartphone app, which allows limiting Audyssey eq to frequencies below a user-set limit. There is some controversy about that...what's your take on it? And thanks again!!
Jack
 

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Thank you, Ray and Mike for your valued insights, and for all the help you've provided to us in the community.


I don't yet have my Marantz SR7011 hooked up, so cannot run both subs together just yet (nor use Audyssey MulteqXT32)...but I suspect that the PB13 will still produce strong bass to 20 Hz, and the PC12+ will not. Both are set to 20 Hz, all ports open.


Probably will be lusting for another PB13U or a PB4000 (which SVS says is the best match).


The lowest room mode for a 17' 8" length should be 32 Hz if I understand this correctly. Wanting to put the main listening position abt 3/4 back from the front wall, and take advantage of room mode cancellation per Floyd Toole's book Sound Reproduction (third edition, Chapter 8, Sec. 8.2.6). If that arrangement of subs being located center of front and back walls doesn't help much, then I'll be free to try other sub locations. Hoping to let Audyssey XT32 deal with other room modes, at least up to the transition frequency.


Which brings up another question, semi-off-topic: my receiver is compatible with Audyssey smartphone app, which allows limiting Audyssey eq to frequencies below a user-set limit. There is some controversy about that...what's your take on it? And thanks again!!
Jack

You are very welcome, Jack! I think your initial starting positions sound fine. It's just that you won't know what you like best until you actually try them with your new sub, and with XT-32.

There are two different issues involved with respect to the app. The first is whether you want to limit the use of automated room EQ above a certain frequency. That is strictly a YMMV issue, to be decided on the basis of either theory or experimentation, depending on the individual. The second issue involves the current below 20Hz roll-off that the app provides. Most people consider that feature a glitch, and I understand that a software update, in the very near future, will allow users to disable that feature.

I won't take a strong position on the use of room EQ, above a particular frequency, because I think it depends on too many room, speaker, listener factors. That's why I called it a YMMV issue. Speaking personally, Audyssey works very well for me, full-range. To be fair, I also have a good acoustical starting point in my room, and a lot of experience in using Audyssey.

But, I would definitely not want my subs to roll-off below 20Hz in my room. And, I would always want to have the choice, even if I intended for them to roll-off. Darth, for instance, wants his subs to roll-off below about 25Hz, due to excessive room rattles in his HT. I completely understand that, and I might make the same choice in his room.

But, for those of us who don't have specific reasons for preferring a <20Hz roll-off, there is an awful lot of very low-frequency entertainment to be found in many 5.1 movies. I personally enjoy both the low-frequency sounds and the tactile sensations, and I absolutely wouldn't want my subs to roll-off below 20Hz, due to the operation of the Audyssey app. But then, my room is built like a tank in terms of rattles. I hope this clarification helps!

Regards,
Mike
 

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You are very welcome, Jack! I think your initial starting positions sound fine. It's just that you won't know what you like best until you actually try them with your new sub, and with XT-32.

There are two different issues involved with respect to the app. The first is whether you want to limit the use of automated room EQ above a certain frequency. That is strictly a YMMV issue, to be decided on the basis of either theory or experimentation, depending on the individual. The second issue involves the current below 20Hz roll-off that the app provides. Most people consider that feature a glitch, and I understand that a software update, in the very near future, will allow users to disable that feature.

I won't take a strong position on the use of room EQ, above a particular frequency, because I think it depends on too many room, speaker, listener factors. That's why I called it a YMMV issue. Speaking personally, Audyssey works very well for me, full-range. To be fair, I also have a good acoustical starting point in my room, and a lot of experience in using Audyssey.

But, I would definitely not want my subs to roll-off below 20Hz in my room. And, I would always want to have the choice, even if I intended for them to roll-off. Darth, for instance, wants his subs to roll-off below about 25Hz, due to excessive room rattles in his HT. I completely understand that, and I might make the same choice in his room.

But, for those of us who don't have specific reasons for preferring a <20Hz roll-off, there is an awful lot of very low-frequency entertainment to be found in many 5.1 movies. I personally enjoy both the low-frequency sounds and the tactile sensations, and I absolutely wouldn't want my subs to roll-off below 20Hz, due to the operation of the Audyssey app. But then, my room is built like a tank in terms of rattles. I hope this clarification helps!

Regards,
Mike
Very true!!!
And I am sure, I am missing a lot from all the posts mentioning very low frequency:(

Thank you, Ray and Mike for your valued insights, and for all the help you've provided to us in the community.


I don't yet have my Marantz SR7011 hooked up, so cannot run both subs together just yet (nor use Audyssey MulteqXT32)...but I suspect that the PB13 will still produce strong bass to 20 Hz, and the PC12+ will not. Both are set to 20 Hz, all ports open.


Probably will be lusting for another PB13U or a PB4000 (which SVS says is the best match).


The lowest room mode for a 17' 8" length should be 32 Hz if I understand this correctly. Wanting to put the main listening position abt 3/4 back from the front wall, and take advantage of room mode cancellation per Floyd Toole's book Sound Reproduction (third edition, Chapter 8, Sec. 8.2.6). If that arrangement of subs being located center of front and back walls doesn't help much, then I'll be free to try other sub locations. Hoping to let Audyssey XT32 deal with other room modes, at least up to the transition frequency.


Which brings up another question, semi-off-topic: my receiver is compatible with Audyssey smartphone app, which allows limiting Audyssey eq to frequencies below a user-set limit. There is some controversy about that...what's your take on it? And thanks again!!
Jack
First, you are more than Welcome:)
Mike and I do-it for our love of Audio, and trying to help out from our knowledge for this Hobby that is slowly dying for convenience (side story, I was told today to move on with time [just bought a flip phone], my reply was [sure, I will watch from now on movies, on a big smart phone instead of my 10ft screen with 11 speakers and 2 subs] it was the end of this conversation:eek::D).

That said, I really need to order this book since it will be a very good read.
https://www.amazon.ca/Sound-Reproduction-Acoustics-Psychoacoustics-Loudspeakers/dp/113892136X/ref=sr_1_fkmrnull_1?hvadid=74766848086757&hvbmt=bp&hvdev=c&hvqmt=p&keywords=floyd+toole&qid=1555122024&s=gateway&sr=8-1-fkmrnull

And I am sure, I will learn new things:)
While pricy, it might save me money for my future subs. Or push me to a next level of enjoyment with my room:D
Either way, money well spend!
Thank you, for mentioning this book again!
Forgot many time, to add-it to my Favourite to order-it:(


Ray
 

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Audyssey says use only 1 output on the AVR

https://audyssey.zendesk.com/hc/en-us/articles/212347563-Subwoofer-setup-and-MultEQ

In answering the question: "If I have 2 subs, and only 1 output on the AVR, could i use the sub equalizer to integrate both subs into the HT? "


Audyssey Labs on May 17, 2010 11:59 responded: Yes, that is the preferred method even if you have two sub outputs on the AVR.

So use a Y splitter even if you have 2 outputs?

Do you agree?
 

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https://audyssey.zendesk.com/hc/en-us/articles/212347563-Subwoofer-setup-and-MultEQ

In answering the question: "If I have 2 subs, and only 1 output on the AVR, could i use the sub equalizer to integrate both subs into the HT? "


Audyssey Labs on May 17, 2010 11:59 responded: Yes, that is the preferred method even if you have two sub outputs on the AVR.

So use a Y splitter even if you have 2 outputs?

Do you agree?
Simple answer (that I am sure will be expanded upon) is:

If your AVR can independently calibrate dual subs, and the subs are placed randomly around the room...use both sub outputs.

If your AVR can independently calibrate dual subs, and the subs are placed near the front speakers, equidistant to the MLP...use a single sub output.

If your AVR cannot independently calibrate dual subs, it does not matter.
 

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Denon S740H

Simple answer (that I am sure will be expanded upon) is:

If your AVR can independently calibrate dual subs, and the subs are placed randomly around the room...use both sub outputs.

If your AVR can independently calibrate dual subs, and the subs are placed near the front speakers, equidistant to the MLP...use a single sub output.

If your AVR cannot independently calibrate dual subs, it does not matter.
I have a Denon S740H.
 

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I have a Denon S740H.
Only Audyssey MultEQ on that AVR, no SubEQ HT, so your dual sub outputs are in reality an internal y-splitter. Each output gets the exact same signal.
 
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Simple answer (that I am sure will be expanded upon) is:

If your AVR can independently calibrate dual subs, and the subs are placed randomly around the room...use both sub outputs.

If your AVR can independently calibrate dual subs, and the subs are placed near the front speakers, equidistant to the MLP...use a single sub output.

If your AVR cannot independently calibrate dual subs, it does not matter.
+1
And would require manual volume matching for each sub, and phase control for the distance.

Only Audyssey MultEQ on that AVR, no SubEQ HT, so your dual sub outputs are in reality an internal y-splitter. Each output gets the exact same signal.
Ok. Thank you for taking time to respond.
If having the money to upgrade your AVR, to one that do Audyssey XT32.
I would go that road, since after trying to explain the real basic of adjusting the volume for each sub. And there phase control manually on each one.
Unless having lots of basic old school knowledge, it is hard to explain on paper. As seen on this thread;
https://www.avsforum.com/forum/113-subwoofers-bass-transducers/3061290-sw-behind-tv-ok.html

The way an AVR that can do Audyssey XT32, and other calibration system that do two subs (true two sub output, not an internal Y-splitter).
Work that way, on the first sweep of the calibration. It figure out the volume control for each subs (might mention one or both subs, need to be turn-up or down before proceeding to make the sound level closer).
Then the phase for the distance between other and your other speakers, than do a calibration of your room as one sub.
Why one sub, movie/music recording only have only one bass sound track output (the .1).

While my Marantz 7702mkII, say 11.2
It only mean two independent sub cannels, for the first sweep of the calibration.
(To figure out the volume and phase of each subs, after that it does the calibration as one sub, as mention in my previous paragraph).
I use to say, I got a 7.4.2 system. I now say 7.4.1 (two subs) system.


Ray
 

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Measurements are better than ears sometimes

Hi folks!
I found my SPL meter, and what a revelation. My PC12+ has useful output to below 20 Hz, and will keep up with my PB13U until the volume demand is too great for the little guy!


Positioning subs to cancel room mode resonance does work, I am pleased to report. I've been using a flat signal generator and the SPL meter from abt 15 Hz to 90 or so, then hooked up front L & R towers and ran Audyssey Iphone app. It told me to reverse the polarity to the towers. I dutifully complied, but found out that caused a huge suck-out between abt 70 to 90 Hz, so flipped polarity back. The app did a nice job of flattening lower bass response, but in the range where the towers are crossing in, there is a rise of 6 dB @ 60 Hz, and +8 dB @ 75 Hz. Looks like I'm gonna have to learn how to use some parametric dsp eq. Thanks again for this wonderful forum.


Jack
 

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Hi folks!
I found my SPL meter, and what a revelation. My PC12+ has useful output to below 20 Hz, and will keep up with my PB13U until the volume demand is too great for the little guy!


Positioning subs to cancel room mode resonance does work, I am pleased to report. I've been using a flat signal generator and the SPL meter from abt 15 Hz to 90 or so, then hooked up front L & R towers and ran Audyssey Iphone app. It told me to reverse the polarity to the towers. I dutifully complied, but found out that caused a huge suck-out between abt 70 to 90 Hz, so flipped polarity back. The app did a nice job of flattening lower bass response, but in the range where the towers are crossing in, there is a rise of 6 dB @ 60 Hz, and +8 dB @ 75 Hz. Looks like I'm gonna have to learn how to use some parametric dsp eq. Thanks again for this wonderful forum.


Jack
Hello Jack, thanks for your post and sharing your findings.

For the polarity on your towers, sometime time Audyssey get confuse if having a 4 ways design. Mine is consider 4 ways design, Aperion Verus Grand Tower;
https://www.aperionaudio.com/collections/verus-speakers/products/verus-iii-grand-tower-speaker
Been an MTMWW design. What happen, is sometime the designer put one of the M (mid driver). In a reverse polarity, to take care of what some MTM problem suffer (way above my pay level, to understand).
That said, Audyssey pick-it up, and the reason it say to reverse-it. Has you saw, not always for the best.

The first time it happen to me, I contacted Aperion to check if there was something wrong with my towers.
This is where, I learn that one mid was in reverse by design. So I ignore Audyssey, and continue with the calibration. Work out very well.
Since then, I did many calibration. I got this warning around 20% of the time, the other 80% I do not.
Could be a variations of a few inches, for the microphone positions during calibration.

Like you, I like to use a SPL meter. Been old fashion and sometime having a hard time to understand better tools, like REW.
Since I cannot find my old test CD, I will order this CD to get ready for my new subs;
https://www.musicdirect.com/optical-disc/stereophile-test-cd-1
Mostly, for tracks 20 to 31. And will listen to the first 19 tracks, before and after calibration to see if I can hear a difference.


Ray
 

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Hi folks!
I found my SPL meter, and what a revelation. My PC12+ has useful output to below 20 Hz, and will keep up with my PB13U until the volume demand is too great for the little guy!

Positioning subs to cancel room mode resonance does work, I am pleased to report. I've been using a flat signal generator and the SPL meter from abt 15 Hz to 90 or so, then hooked up front L & R towers and ran Audyssey Iphone app. It told me to reverse the polarity to the towers. I dutifully complied, but found out that caused a huge suck-out between abt 70 to 90 Hz, so flipped polarity back. The app did a nice job of flattening lower bass response, but in the range where the towers are crossing in, there is a rise of 6 dB @ 60 Hz, and +8 dB @ 75 Hz. Looks like I'm gonna have to learn how to use some parametric dsp eq. Thanks again for this wonderful forum.

Jack

Hi Jack,

That's good news that your two subs seem to be working well together! Are you saying that you are measuring a 6db increase in SPL at 60Hz, and an 8db increase in SPL at 75Hz, compared to frequencies above and below that, after running Audyssey? If so, that's very strange. Audyssey's goal is to make all frequencies play +/-3db from 75db when it sets its filters. And, it can pull down peaks by up to 20db. What it can't do, though, is to EQ the speakers in relation to the subs. It EQ's each channel individually. The subs are all EQed as one, as part of the .1 LFE channel.

I don't know where you are crossing from your front speakers to your subs. If your crossover is lower than 80Hz, I would raise it to at least that number, and I might also try 90Hz. I assume that you are running your front speakers as Small and that you aren't using LFE+Main. That feature can mess things up sometimes (often). I really wouldn't like hearing that much extra mid-bass, so I think it would be worth experimenting a bit to see if I could get rid of it.

You can certainly try to use the PEQ built into your SVS sub to see if you can pull down those peaks, but it would be useful here to be able to measure your frequency response with REW. I assume that you can hear the extra mid-bass in the 60 to 75Hz range as well as measure it with an SPL meter? Don't forget that most uncalibrated SPL meters will lose volume as they try to measure lower frequencies, so unless 60-75Hz measures louder than 100Hz or 120Hz, then you may just be seeing the limitations in your SPL meter; especially if you can't really hear that much more mid-bass.

If you do decide to implement some independent PEQ to try to pull down those frequencies, I might consult with Ed Mullen first, if I were you. I hope this helps! :)

Regards,
Mike
 
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