"Official" Audyssey thread Part II - Page 44 - AVS Forum | Home Theater Discussions And Reviews
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post #1291 of 3816 Old 09-29-2016, 11:05 AM
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Originally Posted by Dave-T View Post
The higher the negative number the more bass you will get correct? With Marantz is it like Denon +12 -12?

That's correct, and if your initial trim level is -6, and you want it about 3db louder, just increase the Marantz trim level to -3.

Edit, I just reread the way you phrased your question, and I want to be sure that we are all on the same page. In math, and in audio, -1 is a larger number than -2. So, as you are adjusting the MV in your unit, or adjusting the trim level for a speaker or a sub, you increase volume by going to a lower (larger) negative number. I think that larger is what you meant when you said higher, but just in case.
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post #1292 of 3816 Old 09-29-2016, 11:36 AM
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Quote:
Originally Posted by Dave-T View Post
i just replaced my Denon 4308ci receiver which had XT to a Marantz 8802A which has XT32. Got pretty good at the getting the bass trim to a -3.5 by working with the volume on my sub which is a Velodyne DD10. Now I am all confused with the sub tuner on the XT32 because when I used the bass optimizer I dialed it in just a the boarder of red and green which was 76. The volume on my sub was dialed down to 18 I ran audyseey and after everything was said and done the trim on the sub was -6.0. So my question is how do I get my sub back to -3.5 which sounded great when using XT and the sub volume was 24. I like bass, currently it sounds like I have no bass anymore. Furthermore there is a setting in the processor that lets you adjust the sub level, should I use that to get it back to -3.5 by adding 2.5DB? Any help would be appreciated. Other than that I am loving my new processor.
Don't adjust the trim level there with the 8802 rather use the option button to ajust in the channel levels doing so with the sub trim defaults the level to 0 and any bump over that is going into the possible clipping territory.



Quote:
Originally Posted by Alan P View Post
Your bass is most likely going to sound different to you going from XT to XT32, XT32 usually results in a much flatter bass response that may take you some time to get used to. That being said, there is nothing wrong with liking more bass (sometimes a LOT more) than Audyssey gives you initially.

As long as you are getting an initial sub trim in the negative numbers (but NOT at the lower limit) feel free to bump up the sub trim as much as you want (without going over 0dB).

If you want to get close to where you were with the old AVR, just leave the sub gain at 24 and run Audyssey (skip the sub level matching). Just do the first mic position and "calculate", take a look at the sub trim and if it is still in-range (i.e. not -15dB) you are good to go.If you are at the lower limit, turn the gain on the sub down 1 click at a time and re-run that fist mic position until you are in-range. Then bump up the sub trim to taste and enjoy!
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post #1293 of 3816 Old 09-29-2016, 11:42 AM
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So I got Audssey to read the sub at -3 where it sounded great with XT, however with XT32 -3 sounds horrible no bass. -9 seems to be the sweet spot for bass at least for my taste. Thanks for the all help!

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post #1294 of 3816 Old 09-29-2016, 12:43 PM
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Originally Posted by Dave-T View Post
So I got Audssey to read the sub at -3 where it sounded great with XT, however with XT32 -3 sounds horrible no bass. Where do you find the sub number should be after a calibration where you have tight loud bass with XT32. obviously the XT and XT32 are very different.
XT-32 has many more filters in the subwoofer channel than XT, so in theory, it will do a better job of EQing your sub(s). If I were you, I would redo your calibration. This time, increase the gain on your sub. Audyssey will tell you that your sub level is too high. Ignore that, and do a calibration based on that first mic position. Just tell Audyssey to calculate after running the test tones at mic position 1. Then check the results, and repeat until you get the trim level you want. I would shoot for a trim level of at least -9, but not more than -11. That will give you lots of headroom in your pre-pro to add trim--up to about +9db to +10db.

Most people enjoy increasing their sub trims after calibrating, so just add trim in your Marantz until it sounds good to you. But you don't want to go over 0.0, so you need to start with a low trim number, such as about -10, to give you lots of room to add as much volume as you want.
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post #1295 of 3816 Old 09-29-2016, 01:25 PM
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Originally Posted by Dave-T View Post
The higher the negative number the more bass you will get correct? With Marantz is it like Denon +12 -12?
Mike answered your first question.

I think Marantz are -15 to +15 but that may have changed. You can always just check by going into the speaker trim settings and adjusting one as far as it will go in both directions, then you will know for sure.
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post #1296 of 3816 Old 09-29-2016, 01:30 PM
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Originally Posted by Dave-T View Post
So I got Audssey to read the sub at -3 where it sounded great with XT, however with XT32 -3 sounds horrible no bass. -9 seems to be the sweet spot for bass at least for my taste. Thanks for the all help!
Huh?

There must be a typo in that post because -3dB is louder than -9dB.

Follow mine and Mike's advice and re-calibrate until you get an acceptable initial sub trim level, then boost to your heart's content...well, within reason.


You keep saying it sounded great with XT at -3dB...but what was the initial sub trim?? You may have boosted it post-Audyssey and not remember. My point is that whatever amount of boost you were using with XT, you will want to use approximately the same amount of boost with the new AVR.
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post #1297 of 3816 Old 09-29-2016, 03:29 PM
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Guide to Subwoofer Levels, Audyssey Setup, and DynamicEQ




Subwoofer Levels
:

The most commonly asked question on the Audyssey thread these days involves subwoofer settings. There is a fairly universal perception that bass sounds somewhat softer after running Audyssey, and most people who are new to Audyssey are naturally curious about whether that perception is normal, and if so, about the best way to increase their bass. It is perfectly normal to perceive bass levels as lower after running Audyssey. In examining this issue, I have also been thinking about trying to write a simple explanation of the relationships among sub gain, AVR trim, and master volume (MV). This explanation represents my current understanding of how Audyssey works, and offers some best practice advice for getting the most from your subs. I am also going to include some discussion of how Audyssey sets, and EQ's, single and multiple subs.

The discussion will explain why we may perceive bass levels as lower after calibrating our audio systems to a Reference level, and the various ways which we may add bass to our audio systems. The discussion will emphasize why it is important to use sub amps, rather than AVR amps, to add sub boosts, and to keep AVR trims well in the negative range in the process. The section which follows the subwoofer discussions includes a fairly complete description of DynamicEQ (DEQ), which has a bass boost of its own.

[It should be noted that most of the discussion of how subwoofer levels are set, and of the relationship between sub gain and AVR trim levels, also applies to non-Audyssey audio systems.]

[It is also worth noting that the Audyssey FAQ, which is linked below (and especially the Technical Addendum to the FAQ) have a wealth of additional information and explanation on the operation of Audyssey. Interested readers are highly encouraged to read the FAQ for both quick answers and for in-depth detail.]

First, one of Audyssey's goals, in any Audyssey version, is to set the volume levels of all channels in a system, including subs, to 75db, as measured at the MLP, by the calibrated Audyssey microphone. The MLP is microphone position 1, wherever the user chooses to place the microphone. And, that point in space is where Audyssey will set timing (distance) and trim levels, for all of the channels, to coincide. Where the .1 sub channel is concerned, Audyssey will measure all of the subs in a multi-sub system together, so that their combined SPL is 75db. The trim levels and distances (timing) for all of the channels will be set at mic position 1. Audyssey will disregard any previous settings and set levels, distances, and crossovers from scratch, whenever a new calibration is run.

When Audyssey finishes, all channels in the system will play at the same volume, at the MLP, as determined by the calibrated Audyssey microphone. And, when all channels in a system are playing at the same volume, the sound at the MLP will be in balance with what the film mixer intended to be heard when a movie is played at "Reference" volume. The Dolby, or THX Reference level is capped at a peak volume of 105db for the regular channels, and 115db for the .1 LFE (subwoofer) channel. A system that is calibrated to Reference will, if it has the capability to do so, play those 105db and 115db peaks when the volume control is set at 0.0.

At one time, test tones were employed at the nominal average Reference volume of 85db. Since those test tones were very loud, most systems, including Audyssey, now use a test tone of 75db. AVR's then do an internal recalculation to add 10db to the regular channels, and 20db to the .1 LFE channel. And, the HT system is now calibrated to Reference at a master volume of 0.0.

As noted, for the listener it is important to have all of the speaker channels playing at the same volume at the MLP. But, as a practical matter, starting with all of the channels (including the .1 subwoofer channel) playing at the same volume is probably also the only way to set the audio system to Audyssey Flat. The intent of the Flat response curve is to have every frequency from down to as low as 10Hz, and as high as about 22KHz, play +/- 3db. The Audyssey Reference curve changes Flat, by slightly rolling off the frequencies above 4000Hz (by about -2db) and adding more roll-off (about -6db) above 10KHz. It also adds mid-range compensation (a dip between 2000Hz and 3000Hz). But, to do those curves, Audyssey needs to start with all channels and frequencies playing at the same volume at the MLP.

[Again, it should be noted that a similar methodology, of setting all channels to the same volume, is used by other systems of automated, or manual, calibration.]

Second, the room strongly influences bass response, causing peaks and dips at various frequencies. That is why Audyssey can be so helpful in EQing subs. Audyssey can implement boosts up to 9db and cuts up to 20db, in all of the channels including the .1 subwoofer channel, in order to achieve a flatter frequency response. When Audyssey is successful at flattening out most of those dips and peaks (at least to some extent) the result is a smoother, clearer, and more uniform sound. That less distorted and less boomy sound, without some frequencies peaking at much louder SPL's than other frequencies, may give the impression that there is less overall bass playing. And, there may actually be less bass playing, in some cases, if a particularly noticeable frequency (say at 40 or 50Hz) were peaking quite loudly prior to EQ. So, just hearing bass frequencies in better equilibrium with each other may contribute to the initial impression that there is less bass.

But, there is more to it than that. Most people don't listen at Reference Volumes (0.0 MV) which is where the low frequency content in 5.1 movies was mixed to be in correct balance with other frequencies. Once the volume level of a movie is reduced below Reference, in a typical home theater, those low bass frequencies may be harder to hear, in relation to the frequencies where our hearing is stronger. That is because, as the volume level drops, it will appear to drop faster for frequencies outside our normal hearing range. And, that particularly includes low bass frequencies.

After the level-matching process from mic position 1 is complete, the low frequencies (which, as noted, are harder for us to hear) are playing at the same volume as all of the other frequencies. This phenomenon of lower frequencies being harder to hear than higher ones (except for very high frequencies) is well known. Our hearing is strongest from about 400Hz to about 4000Hz. So, frequencies played by our subwoofers may require more volume than the frequencies played by our regular channels. Some additional explanation of this is included in the section on DEQ, and in the Addendum at the bottom of this post. For even more information, search for Fletcher Munson Curves, or Equal Loudness Contours.

[It should be noted, for the sake of completeness, that the Equal Loudness Contours are based on averages in human hearing. It may be assumed that, as with other human attributes, hearing follows the shape of a bell curve, with some individuals hearing bass frequencies somewhat better and others hearing those same frequencies somewhat worse than the average. Therefore, a given individual may be able to hear lower frequencies relatively better, or relatively worse than would be predicted by reference to the Equal Loudness Contours. Consequently, the final bass levels that we pick may be partly a function of our individual hearing capabilities and also partly a function of our specific psycho-acoustic preferences.]

Audyssey's DynamicEQ (commonly abbreviated as DEQ) slightly boosts the low frequencies (and the high ones in the regular channels) in all channels, including the subwoofer .1 channel, and is engaged by default. That is intended to, at least partly, compensate for the inherent difficulty in hearing lower frequencies, at below Reference volume levels. How much boost DEQ adds varies depending on the MV selected, with more boost added as listening levels go softer, at a rate of about +2.2db per 5db below Reference. So, at -15 MV, for instance, DEQ would add a little over 6db of bass boost to all of the channels, including the sub channel.

Whether DEQ fully restores bass equilibrium to movie soundtracks is an interesting question. Most people seem to prefer more bass boost than DEQ provides, and typically add an independent sub boost, even with DEQ on. With DEQ engaged, the typical sub boost appears to average about +3db to +6db. With DEQ off, sub boosts are typically much larger. Additional information, regarding DEQ, may be found in a later section. But, with or without DEQ, the question of how, and where, to add a sub boost becomes important for many people employing subwoofers in their audio systems.

Third, most modern commercial subs have a gain (sometimes labeled "volume") control. That gain control determines how much voltage will go from the sub amp to the driver (woofer). The initial setting of that gain control will determine where Audyssey sets the trim level for the sub(s). So, if the initial gain control is high, Audyssey will set a low trim setting in the AVR (such as -9) in order to insure that the sub is playing 75db at the MLP, just as all the other channels are. If the gain control setting is low, Audyssey will set a high trim level setting in the AVR (such as -3.0, or 0.0, or even +3.0) to insure that the .1 subwoofer channel is playing at that same 75db level.

Fourth, and this is an extremely important point, it is desirable to make the subwoofer amplifier send voltage to the driver, rather than having that voltage come from the AVR amp, because the subwoofer amplifier is much more robust and powerful than the amps in the AVR. Simply making any adjustments in sub boost using the gain control on the sub(s) would insure that the sub amp is being used. But, most people find it more convenient to make adjustments using the AVR trim controls, with a remote control. And, in that case, it is desirable to start with a high sub gain level, and a low AVR trim level. Using the trim settings in the AVR to make sub volume adjustments allows the user to make convenient and fairly exact (.5db increments) adjustments to subwoofer volume, by using the AVR remote.

Typically, in order to achieve a low AVR trim level, it will be necessary to start with a measured sub SPL of higher than 75db. An SPL level of about 78db to 80db may be required. That would be in the red zone for Denon/Marantz units during the subwoofer level-matching process. Audyssey is specifically trying to set the sub(s) SPL to 75db. That is in the green zone on Denon/Marantz. To get a strongly negative trim level, though, a higher than 75db level will be required, and that will be in the red zone. The specific SPL used is not as important as the resulting low AVR trim level.

[It should be emphasized that there is no particular reason not to just use the gain control on a sub to add volume post-calibration. For people wanting to add really substantial bass boosts--up to, or in excess of 10db or 12db, some gain increase, in excess of the original gain setting, is generally necessary anyway, in order to achieve the bass boost desired by the user. The usual recommendation to employ the AVR trim is more a matter of convenience and accuracy than one of necessity. Some subs don't have digital gain controls, for instance, so fine tuning the gain can be more difficult, as can on-the-fly adjustments. And, it gets even less convenient when multiple subs are connected together, or when gain controls are difficult to access easily. Using the trim controls in an AVR allows for very convenient and precise adjustments in sub volume. But, the most important thing is to make sure that the real boost comes from the subwoofer amp, and not just from the AVR, whichever adjustment method is ultimately employed.]

Assuming that the desired boost is to be accomplished using AVR trim, a low trim level might be defined as -9 to -11, but not exceeding -11.5 in Denon/Marantz units. (With other manufacturers, just determine what the minimum trim level settings are in order to ascertain what your optimum low trim setting should be.) As stated earlier, it may take an SPL of 78db, or higher, to achieve that optimum low trim level. However, it is important not to go lower than -11.5 in trim, in Denon/Marantz units. As noted by Alan in an earlier post, if a trim level of -12 is set, there is no knowing what the actual volume of the sub is. The AVR simply ran out of negative trim at -12. The actual sub volume might be 80db, or even 85db. And, if so, you might not like the way it sounds to have your sub so much louder than the rest of your system. You also could never be sure what your actual sub volume is, and as a result, you could find yourself running out of headroom sooner than expected. So, for instance, you want a negative trim setting not exceeding -11.5 in Denon/Marantz units.

Think of the process of adding a sub boost this way. When you raise the gain level in the sub, so that the sub produces more than 75db at the MLP, you are making a deposit in the bank, of amplifier power from the sub. So, for instance, let's say you start with a trim level in the AVR of -9. Now, you can withdraw amp power from the bank, using your AVR trim control. You would, for instance, do that by increasing your trim setting to -6, or -3. That +3 to +6db boost would be pretty typical, even with DEQ engaged. But, there is no free lunch. As you begin to approach 0.0, the bank deposit of amp power that you made with the higher gain setting is used up, and now you are using AVR amp power, which as noted, is not as powerful. Using AVR amp power can, in some instances, result in clipping (distorting) your subwoofer(s) or it can, in some cases, result in undesirable mechanical noises.

Fifth, there is a relationship between sub volume and master volume (MV). As your MV increases, the subwoofer volume goes up correspondingly, and more demands are placed on the sub. It is important to remember that the subwoofer is not only playing the LFE channel, but also providing bass support for all of the other channels in a typical HT system. So, as the MV increases, the demands on the sub go up much faster than for the other channels, particularly in a movie with a lot of low frequency content. It is worth noting that 5.1 movies can have very low frequency content in all of the channels, and not just in the LFE (low frequency effects) channel. The subwoofer has to (and should) play all of that low frequency content.

It is recommended by a number of subwoofer experts, two of whom are quoted in the FAQ, that it is advisable to keep sub trims negative (below 0.0). That is particularly important as MV's approach, or exceed, -10. In Denon/Marantz units, that is 10db below Reference (or 70 on the absolute scale) in your AVR master volume. One of those experts quoted, Ed Mullen of SVS, has subsequent to the entries in the FAQ, recommended staying in negative trim levels, period. To follow his advice, and to avoid the possibility of distortion, we would want to keep our trim levels in about the -3 to -5 range, at even more moderate listening levels. Again, that is easy to do by raising the gain on the sub, particularly if it has a digital control.

David makes the point, in a post below this one, that high sub gain levels, which still result in high trim levels, are indicative of a sub which is under-powered for the space, and/or the distance from the MLP. It could also be indicative of a specific placement problem, where either the sub or the MLP is located in a null. In the first instance, the only remedy would be a more powerful sub, or multiple subs, or a different (probably closer) sub placement. In the situation where the sub or the MLP were located in a null, a subwoofer crawl should be done to determine proper sub placement. Although sub placement is not a part of this discussion, it is a very important factor in sub performance.

If you never intend to approach -10 MV, then the advice to set your sub gain high enough to obtain a strongly negative trim level will be less important. And, if you don't believe that you will ever want to boost your subs, then starting with a trim level of about -6, or so, would be perfectly fine. But, most people on this and other threads seem to average at least a +3 to +6db bass boost after calibration, and some people add much more than that. When DEQ (with its own bass boost) is not employed, boosts of 12db, or even more, are not uncommon. So, the advice you will most commonly see on this thread is to start with a negative trim setting of about -9 to -11 post-calibration, in order to maximize your ability to add sub boost, with your AVR trim control, while still using the sub gain you deposited in the bank.

Although this advice is not entirely consistent with the explanations and recommendations in the FAQ, I believe that in this particular instance, the current advice on the thread supersedes the advice in the FAQ. I would personally recommend following the advice to maintain a negative sub trim (preferably of about -3, or lower) as a matter of best practice, even if you believe that you will never approach -10 MV. There is no telling who might, inadvertently or otherwise, run the volume control up on your system, or when unexpected peaks in very low bass (in electronically-enhanced music, or in movies) might cause some distortion to occur.

It is unlikely that a good modern sub would be damaged by a bit of distortion, or by an inappropriate use of AVR amp power, but I know of an Orbit Shifter, which is an extremely powerful and well-made sub, that had a fried voice coil (due to overheating) just from playing electronic music, downloaded from You Tube, at a very high volume, with a high AVR trim level. And, even if no damage could ever be done as a result of clipping the sub signal, listening to distorted bass is sort of antithetical to the whole idea of good sound quality, and of using automated room EQ to achieve it. When proper gain/trim protocols are followed, it is also less likely that mechanical noises, such as port chuffing, or of drivers hitting limiters, could occur prematurely. So, an ounce of prevention is worth more than a pound of cure, in this case.

Again, you can use a combination of increased subwoofer gain, and some increase in AVR trim, to raise the volume level on your sub to any level you choose, while still maintaining an AVR trim of -3, or less. That will allow you to achieve any sub volume your sub is capable of producing. And, raising the gain control on the sub(s) post calibration, will have no effect at all on the way that Audyssey EQed your system.


Audyssey and Multiple Subs:

There are many advantages to having multiple subs, and many HT owners do have more than one sub. The process for setting trim levels for multiple subs depends on the version of Audyssey being used. For all versions except XT-32, with SubEQ, there will only be one sub out on the AVR. People with multiple subs will typically Y-connect two or more subs into that single sub out. (In some cases, they may also daisy chain the subs.) It is desirable, to run mic position 1 for each sub independently, letting Audyssey calculate distance and setting gain/trim levels, as described in the section above.

[Note: Although distances and trim levels are always set based on microphone position 1, some more recent AVR's require three mic positions before a calibration can be performed to check trim levels or distance settings.]

In either case, after connecting dual subs into the single sub out, the normal process can be followed to balance the two gain levels symmetrically, increasing or decreasing the gain levels by the same amount, to achieve a good negative trim level. And, distances from multiple subs can be considered, and if necessary, entered manually to more closely correspond to the timing that Audyssey observed when the subs were measured separately.

XT-32, with SubEQ offers users the advantage of having two sub outs, so a pair of subs can be level-matched, and have distances set automatically. If three or more subs are used with XT-32, and two sub outs, the same process could be followed, measuring each sub independently before pairing it, using a Y-connector, and then measuring the combined pair as Sub Out 1 versus Sub Out 2. If you have tactile transducers in your system, they should be disabled or disconnected before running Audyssey. They can be reconnected or turned back on, after the Audyssey calibration, without affecting the room correction that Audyssey has applied.


Audyssey EQ and Multiple Subs:

Beyond the volume, distance, and crossover setting functions performed during calibration, Audyssey is a system of automated EQ, whose purpose is to achieve improved speaker/room interaction for the entire frequency range. Most people realize that the room strongly affects the way our speakers and subs sound, once we move several feet away from them. Audyssey's test tones have a range of 10Hz to about 22,000Hz, and Audyssey EQ's that entire frequency range, depending on the capabilities of the individual audio system.

So, when the 75db test tones are played through each channel, Audyssey is measuring the frequency response at multiple locations, and using a system of fuzzy logic weighting to set filters (technically, control points) for each channel at various frequencies. The goal is to make each channel play 75db +/- about 3db, at every frequency (or cluster of frequencies), and that includes the subs. Audyssey sets filters for each channel independently, with the number and distribution of the filters dependent on the specific version of Audyssey. But, in all versions of Audyssey, and in all other systems of automated EQ with which I am familiar, the sub channel (the .1 channel) is a single channel.

This is an important point! Regardless of the number of subwoofers in a system, Audyssey will create a single set of filters for all of the subs. Even with XT-32, once the level matching is completed, Audyssey will only play separate test tones once, through Sub 1, and Sub 2, and this is for the purpose of setting trim levels and distances separately, so that the sounds of both subs will arrive at the MLP at the same time, and at the same volume. But, for the remaining 7 mic positions, the same test tone is simultaneously played through all of the subs in the system together, however they are physically connected. This is because Audyssey is only setting filters for the combined sound of all of the subs in concert, and not for the individual subs. Again, using the example of a 5.1 system, all five speakers constitute a separate channel, and all five speakers get all 6, or 8 test tones, depending on the version of Audyssey. And, each of the five speakers gets its own filters. But, with the .1 channel, all subs are pinged and EQed together, and there is only one set of filters for all of them.

Audyssey users are encouraged to level-match all of the subs in their audio systems, prior to running a full Audyssey calibration. And, after Audyssey has set EQ filters, it is generally advisable to add or subtract to sub levels in a symmetrical fashion, by increasing or decreasing sub levels by the same amount. Some users are naturally interested in insuring that their subs are performing equal work, by attempting to have their subs both gain-matched and level-matched at all times. However, this is not always going to be the case after an Audyssey calibration, due to the inherently different influences that different room positions may have on the performance of the subs, as measured by the Audyssey microphone during the calibration process.

It is important to level-match the SPL of the subs in a system prior to running the full suite of test tones in order to present Audyssey with a level playing field. As noted earlier, that level-matching process is typically performed at microphone position 1--the MLP. Once the subs are level-matched to produce equal SPL at the MLP, the full six or eight point calibration is performed, and control points are assigned to the combined output of the subs. But, only one set of filters is assigned for the combined frequency response of all of the subs in the .1 channel. Once Audyssey sets those control points, changing the SPL of the subs asymmetrically, by raising the level of one sub and not another, or by adjusting sub levels in opposite directions may be counterproductive. That is because the playing field will no longer be level, as it was when Audyssey set its control points, and that may result in an adverse change to the frequency response.

Whether the change in frequency response will be measurable, or audible, will probably depend on the extent of the difference in sub levels from what Audyssey originally started with. For instance, raising one sub by a decibel while lowering the other one by a decibel, in order to make the output of the two subs match, may result in an imperceptible difference in the overall frequency response. But, it is generally inadvisable to make asymmetrical changes in sub levels without a very good reason to do so, and without the ability to measure the effects of such a change. Negating the positive effects of room EQ is obviously counterproductive to our intent in running the automated EQ to begin with.

In addition to level-matching subs prior to running an Audyssey calibration, regardless of the version of Audyssey employed it is also highly advisable to match similar subs in the system, if at all possible. If the subs in a system have significantly different frequency responses, a single set of filters will not be nearly as helpful in EQing the subs. It is particularly important not to mix ported and sealed subs in a system, unless you have the capability to independently measure results, with something like REW, and have some way to independently EQ the subs, with something like a miniDSP. Again, this is because Audyssey (or other systems of automated EQ) can only EQ all of the subs as a group, producing a collective low frequency sound response.

Here is an example of how Audyssey works. Let's say that you have a ported sub which produces high SPL from 50Hz down to 15Hz, and a somewhat equivalent model of a sealed sub which may produce higher SPL above 50Hz, but which can't keep up with the ported sub below 50Hz. That would be a common scenario. Ported subs are specifically designed to produce louder volumes, within relatively narrow low frequency ranges (usually below about 50 or 60Hz), than their sealed counterparts.

Audyssey, in any version, won't inhibit the stronger sub. In this scenario, the stronger (ported) sub will still play down to it's F3 point of 15Hz and slightly below. And, it won't overdrive the weaker sub by making it try to play lower and louder than it can. It will simply stop setting filters at the combined, detected F3 point. So, if the sealed sub begins to lose 3db of volume, compared to the ported sub, at about 50Hz, Audyssey will stop EQing at 50Hz, specifically to protect the weaker sub from being over-driven by Audyssey filters. And that means, that in this hypothetical scenario, you wouldn't have the benefit of any EQ in that critical low bass region (from 50Hz to 15Hz) where Audyssey is normally very helpful.

Of course, that doesn't mean that you can't try mixing dissimilar subs, and taking your chances that it will still sound pretty good to you. It might. It simply means that when you mix subs with very dissimilar output, or low-end extension, or roll-off characteristics, you can no longer count on automated room EQ to help you improve your frequency response, below the F3 point of the weaker sub. And, there would be no way to predict how effective a single set of filters would be, even above the F3 point of two very dissimilar subs. Life is much simpler if it is possible to have very similar subs in your system.


Audyssey DynamicEQ:

Audyssey's DynamicEQ (DEQ) is a two-tiered program of loudness compensation, designed to maintain acoustic equilibrium in 5.1 movies, at below Reference listening levels. As noted in the previous section, DEQ is engaged by default whenever an Audyssey calibration is performed. Like the Audyssey Reference curve, which is also the default setting, DEQ can be turned off, or slightly modified, as explained later. Although DEQ can be used in TV, music, and gaming applications, it was specifically created to maintain perceived bass (and to some extent, treble) levels at below Reference volumes in 5.1 movies. At Reference (0.0 MV), DEQ does not effect the bass or treble levels in a system, in any way.

DEQ's sole purpose is to maintain an acoustic balance across the entire frequency range, as listening levels drop below Reference in 5.1 movies. Since 5.1 movies are recorded based on the Dolby and THX Reference standards, described in the first section, DEQ was designed to react specifically to volume reductions below that Reference standard, in home theater environments.

The reason why some adjustment to the acoustic balance in 5.1 movies might be necessary is predicated upon the Equal Loudness Contours, explained earlier, which define the way human hearing works. Our hearing is strongest in the range from about 400Hz to 4000Hz (corresponding somewhat to the range of the human voice). But, since our hearing is strongest in that range, we tend to require more volume to hear frequencies that are lower than about 400Hz, and higher then about 4000Hz. Considering just the lower frequencies, for a moment, the lower in frequency we go, the more volume we need in order to hear those sounds in equilibrium with sounds in our more normal hearing range.

That is even more important with 5.1 movies than it is for music, because so much of the bass content of a modern action movie is below 60Hz, and below 30Hz, and frequently even below 20Hz. (With music involving acoustical instruments, on the other hand, relatively little content is below about 50Hz or 60Hz, and almost none is below 30Hz.) Modern 5.1 movies are mixed with a clear understanding of how human hearing works, and low bass sounds are amplified, with respect to other sounds in the film's soundtrack, in order to make them appropriately audible.

So, low bass special effects, involving explosions for instance, will sound appropriately shocking at Reference, or near Reference, volumes. But, that equilibrium among the easy to hear, and harder to hear frequencies, is only correct at a listening volume of approximately 0.0 MV. In other words low, mid, and high frequencies are designed to be in equilibrium at close to Reference volumes, but may not remain in balance as listening levels drop very far below Reference.

So, for instance, if we were to listen at about -10 MV, we would be listening only about half as loud as film mixers intended. And, in that case, we would still hear sounds quite well in our normal 400Hz to 4000Hz hearing range. But, we would need additional amplification of very low, and perhaps of some very high frequency sounds, to hear those sounds in the same way that the film mixer intended for us to hear them. Otherwise, for example, low bass sounds such as the rumble of thunder, or a train on the tracks, or even the sound of an explosion, would be somewhat muted, detracting from the realism of the scene. Since, average listening levels on AVS appear to be in the range of about -20 to -10 MV, and each reduction in SPL, of 10db, is a halving in perceived volume, that attenuation of low bass sounds can be quite a problem. (It should be noted, that most people seem better able to compensate for corresponding attenuations in high frequency sounds. Many users are completely unaware that DEQ is even slightly boosting very high frequencies, and may not notice the difference in high frequencies, if DEQ is disengaged.)

As noted, DEQ was specifically designed to restore acoustic equilibrium in 5.1 movie soundtracks, at below Reference levels. DEQ does that by providing approximately +2.2db of bass boost, and a little less than +1db of treble boost, for each 5db reduction in master volume, below Reference (0.0 MV). So, for instance, at -5 MV, DEQ boosts the bass by +2.2db; at -15 MV, the boost would be +6.6db; and at -25 MV, the boost would be +11db. That boost is applied in all of the channels, including the .1 LFE channel.

In DEQ's target curve, the bass boost increases gradually, starting almost unnoticeably at about 200Hz. At about 120Hz, DEQ adds about +1db per -5 MV. And, that +1db boost continues down to 70Hz. Then, starting at 70Hz, the bass boost increases gradually, reaching a maximum of +2.2db at 30Hz. That maximum boost of +2.2db per -5 MV continues below 30Hz to the limit of the low frequency response of the subwoofer(s). The treble boost occurs primarily from 10KHz, and up, and is less than half the boost which is applied to the bass frequencies. Based on anecdotal reports from users, the treble boost in DEQ is so gentle as to be unnoticeable by most users.

[Note: For more information on how the DEQ curve is applied, please consult the Audyssey FAQ. The FAQ section on the Reference Level Offset feature of DEQ, discussed later in this section, has graphs showing DEQ's operation at several different master volume levels. Those graphs may be found in Section a)3 of the FAQ. It should also be noted that, as stated in the first section, many users add a personal sub boost to the one that DEQ provides. This is so typical that it may indicate that, for the majority of users, DEQ does not quite succeed in restoring bass equilibrium to movie soundtracks, watched at below Reference volumes. And, given the nature of DEQ's target curve, which emphasizes the very low bass over the mid-bass, it may be that some users prefer more mid-bass boost, compared to the very low bass boost of DEQ.]

DEQ was described above as having a two-tiered operation. According to Audyssey's creator, Chris Kyriakakis, DEQ monitors both the master volume, and the volume of individual channels, in real time. DEQ then adds boosts, in accordance with the maximum limits, listed above, based on the actual volume levels and content, at that moment. This moment-to-moment action has never been explained in any detail, so I am not able to clarify Audyssey's specific actions in this regard. But, from comments made by its creator, DEQ is adjusting both the overall bass volumes, and some individual channel bass levels, on the fly. Those adjustments are made in accordance with DEQ's target curve, which was described above.

In addition to restoring acoustic equilibrium to 5.1 movie soundtracks, at below Reference levels, the designers of DEQ also decided to add another feature to the DEQ software program. Reasoning that sounds from behind were harder to hear than sounds from in front, or from out to the side (due to our pinnae--ear flaps--which funnel sounds into our ear canals) DEQ was also designed to boost all surround channels. That boost increases, as the master volume goes down, at a fixed rate. I believe that about 1db of surround boost is added for every -5db of MV. So, at a listening level of -15 MV (which is a nominal average) there would be approximately 3db of surround boost. Some users find the surround boost of DEQ helpful, or unnoticeable. Other users, who prefer not to hear a surround boost, often slightly reduce individual surround trims. And, some use the Reference Level Offset (RLO) feature to attenuate the surround boost.

Recognizing that not everyone likes the full effects of DEQ, for all types of listening material, Audyssey added the Reference Level Offset to later versions of DEQ. The Reference Level Offset attenuates the effects of DEQ by controlling the point at which DEQ engages. It does that by literally offsetting the Reference point. When an RLO setting is engaged DEQ will recognize Reference as being at a lower volume, and will not start its operation until a volume even lower than that new Reference point is achieved.

As with DEQ, in general, the RLO settings are applied in 5db increments. So, at the lightest RLO setting of -5, Reference is offset by -5db, and DEQ does nothing at a master volume of -5, and adds a bass boost of +2.2db at -10 MV. At an RLO setting of -15, which is the strongest setting, DEQ would not actually commence operation until a master volume of -20 was reached, and it would add only +2.2db of bass boost at that master volume. Again, the RLO settings change where DEQ starts its operation, and that in-turn, reduces DEQ's effect at lower listening volumes. The lightest setting is -5, the medium setting is -10, and the heaviest setting is -15. Some people, who listen at lower volume levels, find the RLO settings particularly helpful with DEQ.

DEQ's operation has always been among the most controversial features of the Audyssey software, and as noted in the first section is completely independent of the filters that Audyssey sets for all of the channels, including the subwoofer channel. So DEQ can be turned on or off without affecting the room EQ in any way. Individuals new to Audyssey, or curious about DEQ, are encouraged to experiment. As noted earlier, some people use DEQ for everything, and some people don't use it for anything. Every combination in between those two extremes has also been noted on the Forum. Different RLO settings may produce positive results with DEQ, as may independent sub boosts, and tone control boosts of the front speakers. (The tone controls, which only apply to the front speakers, are enabled when DEQ is disengaged.)

There is no single right way to operate the various sub-programs and features of Audyssey. Personal decisions regarding the use of DEQ alone, or with an additional sub boost, or with an RLO setting engaged, are just as much a matter of individual preference as is DEQ off, with additional personal tweaks to restore acoustic equilibrium (or not) to a particular audio track. As with the choice to use Audyssey Reference, versus Audyssey Flat, the decision of whether or not to use DEQ (in whatever setting) will depend heavily on individual rooms, systems, and listener preferences.


Addendum on the Thread History of Recommended Sub Trim Settings:

In the months since I first wrote this post, I have come back to it several times to add details or to clarify points that I thought were important. And, I have done that because I thought it would be valuable to have a single source for the best practice recommendations which have evolved on the thread. The FAQ can only be amended by the Author, Keith Barnes. And, Keith has been very busy developing a new dedicated HT. So, this post seemed to be the next best alternative.

But, I thought it might be helpful to explain a bit how the advice on the thread has evolved in recent years. For those who remember, the original advice regarding sub trim levels, was to keep them within a range of about -5 to +5. And, the FAQ reflected that advice. Then, after much discussion on the thread, about how sub amps can clip with higher trim settings, the recommended trim setting range in the FAQ was lowered to -3.5 to +3.5, and the advice from Mark Seaton and Ed Mullen was included. But, as explained above, that FAQ recommendation of -3.5 to +3.5 is still too high, particularly depending on master volume levels. Sub placement, with respect to nulls, could also exacerbate a higher trim setting, as Audyssey might already be adding up to 9db of boost, at some frequencies.

I also remember people, including myself, speculating that Audyssey sets trim levels conservatively, perhaps in an effort to protect less capable subs. I specifically mentioned that to people inquiring about wanting to boost their subs after Audyssey set the trim levels. And, it seemed like a plausible explanation. But, that explanation was never really correct. Audyssey protects less capable subs by not setting filters (control points) below the F3 points of those subs. Audyssey does the same thing with the other channels, setting no control points below the measured F3 of a speaker, or speaker pair. But, it is still the obligation of the user to follow good procedures to insure that the sub(s), and other speakers in an audio system, are used correctly, and are not pushed beyond their specific capabilities.

Audyssey's actual reasons for setting the sub trim levels where it does was explained above. Audyssey uses a 75db test tone to set all of the channels in a system to the same level, as measured at the MLP, so that Audyssey can apply filters to all of the channels, in an effort to achieve a relatively flat frequency response. It can't do that unless all of the channels, including the .1 sub channel, are set to the same volume. And, setting all channels to the same volume, with a 75db test tone, is now pretty much a standard of the industry even for systems having little to no automated room EQ.

But, human hearing is designed/adapted to hear best from about 400Hz up to about 4000Hz. Our hearing quite naturally corresponds somewhat to the range of the human voice. As frequencies drop below about 400Hz, and particularly below about 200Hz, it takes more volume for us to hear those frequencies, at the same perceived level, than it does for the ones in our optimum hearing range. The more that frequencies drop below 100Hz, the harder it is for us to hear them, and the more volume we require in order to do so. That additional volume, particularly for frequencies from about 120Hz down, is typically added via a sub boost. The phenomenon of declining audibility, at lower (and higher) frequencies, is graphically illustrated in various depictions of the Equal Loudness Contours.

If we all listened at Reference levels (0.0 MV) it is unlikely that we would need much bass boost, except that which is added for personal preference. But, most of us don't listen at nearly that volume level. The most common range I see quoted for the average listening level is from about -20 to -10 MV, and some people listen at much lower volumes than that. So, for the great majority of HT users, it was never really about Audyssey setting subwoofer levels conservatively. For most of us, it was always about needing more volume to hear subwoofer frequencies, in equilibrium with higher frequencies, at below Reference levels.

As noted earlier, very high frequencies are also outside our optimum hearing range, but most of us seem to compensate better for some attenuation in the relative loudness of those frequencies. In fact, some studies indicate that most people prefer some high frequency roll-off, and the Audyssey Reference curve is based on that assumption. But, almost all of us seem to perceive a reduction in bass volumes more easily. How much additional bass we need, or want, in order to perceive our sound as balanced, or to fully appreciate the low bass in music, or in movies, is a very personal decision, which probably depends on a lot of factors, including specific rooms, sub capabilities, sub placement, individual hearing, and personal preference.

But, I thought it might be helpful to review how some of the thinking on the thread has changed over the years, with respect to why we may want to add sub boosts, post-Audyssey, as well as the best protocol for doing so. None of this is to suggest that other Audyssey users, and specifically the people involved in the creation of the FAQ, haven't already understood these concepts perfectly well. But, the FAQ was written, and edited, over a period of several years, with some sections being revised, and others not. Someone trying to understand whether it is normal to boost his subs, after an Audyssey calibration, may not get the impression that a sub boost is fairly typical, at below Reference volumes, for reasons that may transcend simple issues of personal preference. And, of course, personal preference will still always be an important factor in the individual implementation of our audio systems.

To summarize the best practice recommendation for adding sub boosts: it is to try to keep AVR sub trim levels no higher than approximately -5 to -3, after adding however much sub boost may be preferred. And, in order to do that, the appropriate use of subwoofer gain, and not just AVR trim, is generally required.

Regards,
Mike

Last edited by mthomas47; 09-17-2017 at 11:47 AM.
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post #1298 of 3816 Old 09-29-2016, 03:53 PM
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Huh?

There must be a typo in that post because -3dB is louder than -9dB.

Follow mine and Mike's advice and re-calibrate until you get an acceptable initial sub trim level, then boost to your heart's content...well, within reason.


You keep saying it sounded great with XT at -3dB...but what was the initial sub trim?? You may have boosted it post-Audyssey and not remember. My point is that whatever amount of boost you were using with XT, you will want to use approximately the same amount of boost with the new AVR.
Sorry, I was talking about the trim level that audyessy lists in the details after the calibration being being set to -9. I have never changed any of the trim levels after the calibration is completed, I leave it as Audyessy sets it. the only thing I change are the crossovers and the speaker size. i noticed now that since i bypassed the sub eq and did not lower my actual subs voulme to get it into the 75db range all of my other trim levels are lower for example my center channel was set at "0" and before it was at +1 when i did use the sub eq at the recommended 75db. Will not using the sub eq effect the rest of the speaker trim levels as well?
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Sorry, I was talking about the trim level that audyessy lists in the details after the calibration being being set to -9. I have never changed any of the trim levels after the calibration is completed, I leave it as Audyessy sets it. the only thing I change are the crossovers and the speaker size. i noticed now that since i bypassed the sub eq and did not lower my actual subs voulme to get it into the 75db range all of my other trim levels are lower for example my center channel was set at "0" and before it was at +1 when i did use the sub eq at the recommended 75db. Will not using the sub eq effect the rest of the speaker trim levels as well?
Hi,

I thought that's what you meant, and it's perfectly fine to not raise the trim level on your sub after Audyssey runs. But, if you ever want more bass...

It might help to read the explanation in the post just above yours. Audyssey will set the trim levels in your satellites completely independently of anything you do with your subs. All channels will be set to 75db, as measured at the MLP. Sometimes, trim levels vary slightly from calibration to calibration, depending on mic placement. But, all of the trim levels will be set to the same 75db in each calibration.

Regards,
Mike
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Thanks for all of your help guys. Mike's post above really helped.
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post #1301 of 3816 Old 09-29-2016, 05:42 PM
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The most commonly asked question on the Audyssey thread these days involves subwoofer settings. I have been thinking about writing a simple layman's explanation of the relationships among sub gain, AVR trim, and master volume (MV). The main reason I will write a simple layman's explanation is because it's the only kind I can write. So, here goes.

First, Audyssey's goal, in any Audyssey version, is to set the volume levels of all channels in a system, including subs, to 75db, as measured at the MLP, by the calibrated Audyssey microphone. The MLP is microphone position 1. Where subs are concerned, Audyssey will measure all of the subs together so that their combined SPL is 75db. When Audyssey finishes, all channels in the system will play at the same volume, as determined by the Audyssey microphone.

Second, most modern commercial subs have a gain (or volume) control. The initial setting of that gain control will determine where Audyssey sets the trim level for the sub(s). So, if the initial gain control is high, Audyssey will set a low trim setting in the AVR (such as -9) in order to insure that the sub is playing 75db at the MLP. If the gain control setting is low, Audyssey will set a high trim level setting in the AVR (such as -3.0, or 0.0, or even +3.0) to insure that same 75db.

Third, it is desirable to make the subwoofer amplifier send voltage to the driver, rather than having that voltage come from the AVR amp, because the subwoofer amplifier is much more robust and powerful than the amps in the AVR. Therefore, it is desirable to start with a high gain level and a low trim level.

A low trim level might be defined as -9 to -11, but not exceeding -11.5 in Denon/Marantz units. As noted by Alan in an earlier post, if a trim level of -12 is set there is no knowing what the actual volume of the sub is. The AVR simply ran out of negative trim at -12. The actual sub volume might be 80db, or even 85db, instead of 75db. And, if so, you might not like the way it sounds with your sub(s) so much louder than the rest of your system. And, you could find yourself running out of sub headroom sooner than expected. So, you want a negative trim setting not exceeding -11.5 in Denon/Marantz units.

Think of it this way. When you raise the gain level in the sub, so that the sub produces more than 75db at the MLP, you are making a deposit in the bank, of amplifier power from the sub. So, for instance, let's say you start with a trim level in the AVR of -9. Now, you can withdraw amp power from the bank, using your AVR trim control. You would do that by increasing your trim setting to -6, or -3, or even 0.0. As noted earlier, volume increases as the numbers get larger, with -1 being a larger number than -2. But, there is no free lunch. As you approach 0.0, the bank deposit of amp power that you made with the higher gain setting is used up, and now you are using AVR amp power, which as noted, is not as powerful. Using AVR amp power can, in some instances, result in clipping (distorting) your subwoofer(s).

Fourth, there is a relationship between sub volume and master volume (MV). As your MV increases, more demands are placed on the sub. It is recommended by a number of subwoofer experts, two of whom are quoted in the FAQ, that it is advisable to keep sub trims negative (below 0.0) as MV's approach or exceed -10. That is 10db below Reference (or 70 on the absolute scale) in your AVR master volume.

If you never intend to approach -10 MV, then the advice to set your sub gain high enough to obtain a strongly negative trim level will be less important. And, if you don't believe that you will want to boost your subs, then starting with a trim level of -6, or even -3, would be perfectly fine. But, most people on this and other threads seem to average at least a +3 to +6db bass boost after calibration. So, the advice you will most commonly see on this thread is to start with a negative trim setting of about -9 to -11 post-calibration, in order to maximize your ability to add sub boost, while still using the sub gain you deposited in the bank.

Although this advice is not entirely consistent with the recommendation in the FAQ, I believe that in this particular instance, the advice on the thread supersedes the advice in the FAQ. And, I would personally recommend following this advice as a matter of best practice, even if you believe that you will never approach -10 MV. There is no telling who might, inadvertently or otherwise, run the volume control up. It is unlikely that a good modern sub would be damaged by some distortion, but I know of an Orbit Shifter, of all things, that had a fried voice coil just from playing electronic music, downloaded from You Tube, at a very high volume with a high AVR trim level. And listening to distorted bass is sort of antithetical to the whole idea of using automated room EQ, in the first place. So, a penny's worth of prevention is worth more than a pound of cure, in this case.

I hope this explanation of sub gain, vis-a-vis trim gain, and MV, is helpful.

Regards,
Mike
There are only 3 things I'd add to Mike's excellent post.

My first thing is implicit in Mike's post. If you have to use a high gain setting on the sub and Audyssey is setting a high trim level, one close to 0 or even above 0, then you can easily run into distortion issues at high master volume settings. The sort of thing which could lead to that situation is the combination of a small underpowered sub in a large room with a long listening distance. Producing decent listening levels at low frequency at some distance in a large room is not something that small subs with low power amps are good for.

That point leads to my second point which is about using 2 subs, something Mike didn't mention here. There are 2 benefits to using multiple subs. The first is that their outputs sum so neither sub has to be driven as hard as a single sub in order to reach the same listening level. That's a handy point for people with small subs in the situation I mentioned above. If you want to raise the level of output from your sub and your gain and trim settings are high, that's a good sign that you need either a bigger sub or an additional sub, The second benefit is that multiple subs can help smooth low bass response in a room and that makes the job of correcting sub response easier so there can be an advantage to using 2 subs rather than a single, larger sub.

The third thing I'd add is Mike's comments made less than a day ago about using more than one sub. I'll quote him exactly:

"If you currently have sealed subs, then I would recommend that you stay with sealed for any future subs. Conversely, if your other subs are ported, then you would want to add ported subs. Mixing ported and sealed subs can be a very difficult proposition from the standpoint of achieving a good frequency response. And, it's really not something that automated EQ, such as Audyssey XT-32 can help with, because the frequency responses, and roll-off rates, of ported and sealed subs are so different. Ideally, you want to try to match the capabilities of your subs as much as possible, unless you are either willing to accept potential problems with the frequency response, or are willing to dive deeply down the rabbit hole with REW, and an outboard DSP, such as a miniDSP.

For the great majority of users, including myself, the advice to stay with identical, or as nearly identical subs as possible, is both the simplest and best advice."

The only change to that quote which I would make if Mike wants to add it to his general sub guide is to reverse the order of the 2 paragraphs so that the general advice comes first and the expansion of that advice in relation to types of subs etc comes second.
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Hi Mike,

Thank you very much for your explanation.

I will try to just manage for -11 db trim level, and afterwards just up the trim level to which sound good to my ears. I will follow all the steps that you all taught me about level matching all four subs before run Audyssey, and so on.

My 5.1 system I bought back then in 1999, with one sub only and it's REL, and didn't really care much. Fast forward to last year, after reading a lot online I decided to get the Klipsch R-115SW, it's cheap, and it sounded better than the REL I have, especially for movies. So, I bought second one, and sounded even better, the final result was I have four now.
But sometimes cheap means expensive...

Then I read more from AVS and other sites. Not long ago I exchanged a few posts with Mr. Vodhanel from PSA in the UK AVForums (he has got UK distributor for his products), to get his idea and opinion between sealed and ported subwoofers.
PSA subs got my attention since lots of members talk about PSA subs over here. And back then I was planning a trip to New York so I asked if I could visit his workshop since his address (from PSA site) was not that far from the Big Apple.
I didn't get further reply.
Then last month by posting question about XTZ 3x12 here at AVS, I got the chance to email Mr. Permanian, to get price quote for his subs to ship to Europe, and he replied. Somehow, when I asked if the quoted prices are included import duty, and how he support overseas clients, I got no more reply.
You cannot afford if you have to ask...

And so, I decided to fully concentrate on subs that I can get it easy here in Europe, that's why I was asking about SVS and XTZ. And of course, there is this new sub from L-Sound as you already know.
The reason I want to change all four R-115SW is I have heard the XTZ 3x12, I think that I mentioned it to you, and that sub surely sounded better than mine! And while I was in New York my colleague showed me his system, he has got Magico S series included its subwoofer, and the sealed sub sounded even better, in his place of course. He used to have JL Audio F113.

I have read and now you mentioned as well that one shouldn't mix sealed subs with ported subs, that was why I first asked about the PC13. Now I would like to experience sealed subs, XTZ doesn't make sealed sub and L-Sound's sealed sub looks nice but no real reviews but quite popular in the UK, and so come down to only SB13, as it's been there long and got good reviews everywhere.

At one point I was ready to add two Behringer B1200D since I read some members here had such good experience, and after a careful thought I gave up the idea.

Thanks again for your time!



Jim
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Hi Mike,

Thank you very much for your explanation.

I will try to just manage for -11 db trim level, and afterwards just up the trim level to which sound good to my ears. I will follow all the steps that you all taught me about level matching all four subs before run Audyssey, and so on.

My 5.1 system I bought back then in 1999, with one sub only and it's REL, and didn't really care much. Fast forward to last year, after reading a lot online I decided to get the Klipsch R-115SW, it's cheap, and it sounded better than the REL I have, especially for movies. So, I bought second one, and sounded even better, the final result was I have four now.
But sometimes cheap means expensive...

Then I read more from AVS and other sites. Not long ago I exchanged a few posts with Mr. Vodhanel from PSA in the UK AVForums (he has got UK distributor for his products), to get his idea and opinion between sealed and ported subwoofers.
PSA subs got my attention since lots of members talk about PSA subs over here. And back then I was planning a trip to New York so I asked if I could visit his workshop since his address (from PSA site) was not that far from the Big Apple.
I didn't get further reply.
Then last month by posting question about XTZ 3x12 here at AVS, I got the chance to email Mr. Permanian, to get price quote for his subs to ship to Europe, and he replied. Somehow, when I asked if the quoted prices are included import duty, and how he support overseas clients, I got no more reply.
You cannot afford if you have to ask...

And so, I decided to fully concentrate on subs that I can get it easy here in Europe, that's why I was asking about SVS and XTZ. And of course, there is this new sub from L-Sound as you already know.
The reason I want to change all four R-115SW is I have heard the XTZ 3x12, I think that I mentioned it to you, and that sub surely sounded better than mine! And while I was in New York my colleague showed me his system, he has got Magico S series included its subwoofer, and the sealed sub sounded even better, in his place of course. He used to have JL Audio F113.

I have read and now you mentioned as well that one shouldn't mix sealed subs with ported subs, that was why I first asked about the PC13. Now I would like to experience sealed subs, XTZ doesn't make sealed sub and L-Sound's sealed sub looks nice but no real reviews but quite popular in the UK, and so come down to only SB13, as it's been there long and got good reviews everywhere.

At one point I was ready to add two Behringer B1200D since I read some members here had such good experience, and after a careful thought I gave up the idea.

Thanks again for your time!


Jim
Hi Jim,

You are very welcome! I am glad to be able to help a little. I completely understand about your subwoofer journey. My own was somewhat similar, starting with a SuperCube. I wish there were a way to shortcut the learning curve, but if so, I don't know what it is. I also understand why you would want to upgrade from your current subs. I think that the decision of whether to go sealed or ported is a personal one, based not so much on sound quality (as any differences among comparable performers would be very small) but more on room size versus listening level. If your room size is around 3000^3, or so, and you want to listen at high volumes, with a sub boost, ported subs are an easier way to get the combination of extension and output that you may be looking for.

But ported subs are also larger and more expensive than somewhat comparable sealed subs. And if you are going to continue to have four subs, then sealed could be a good way to go. But, four sealed Ultras would not give you a very big performance upgrade compared to the Klipsch subs you have now, simply because ported subs are more powerful down low. So, for instance, four SB13's would actually offer a little less output at 20Hz than your 115's. You can compare the Data-Bass numbers in the chart I linked earlier, to the 2m results in this review of your current subs. http://hometheaterreview.com/klipsch...viewed/?page=2

If it's more low-end extension, and output you are after, I think you would be better off going with the XTZ ported subs, or the other established performers like the ported Ultra. I know the XTZ subs are very large (which is why they can go pretty low with real authority), and that you may have trouble finding ported Ultras where you are. And I would not wish to discourage you from trying SVS sealed subs. But, I think it's important to identify your short and long-term bass goals as you buy. To me, that's the single most important lesson I have learned.

If it's low frequency extension, coupled with sheer output you are after, it takes a lot of sealed subs to equal the output of four ported subs. And even two 3X12's would be more powerful than four SB13's, so you could consider having only two, or three subs, instead of four. (They are also compared in the Data-Bass table.) On the other hand, if you are not currently using all of the output you have available with your 115's, anyway, then four sealed SB13's might give you improved SQ, and still have sufficient output for your requirements.

I hope this helps!

Regards,
Mike
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There are only 3 things I'd add to Mike's excellent post.

My first thing is implicit in Mike's post. If you have to use a high gain setting on the sub and Audyssey is setting a high trim level, one close to 0 or even above 0, then you can easily run into distortion issues at high master volume settings. The sort of thing which could lead to that situation is the combination of a small underpowered sub in a large room with a long listening distance. Producing decent listening levels at low frequency at some distance in a large room is not something that small subs with low power amps are good for.

That point leads to my second point which is about using 2 subs, something Mike didn't mention here. There are 2 benefits to using multiple subs. The first is that their outputs sum so neither sub has to be driven as hard as a single sub in order to reach the same listening level. That's a handy point for people with small subs in the situation I mentioned above. If you want to raise the level of output from your sub and your gain and trim settings are high, that's a good sign that you need either a bigger sub or an additional sub, The second benefit is that multiple subs can help smooth low bass response in a room and that makes the job of correcting sub response easier so there can be an advantage to using 2 subs rather than a single, larger sub.

The third thing I'd add is Mike's comments made less than a day ago about using more than one sub. I'll quote him exactly:

"If you currently have sealed subs, then I would recommend that you stay with sealed for any future subs. Conversely, if your other subs are ported, then you would want to add ported subs. Mixing ported and sealed subs can be a very difficult proposition from the standpoint of achieving a good frequency response. And, it's really not something that automated EQ, such as Audyssey XT-32 can help with, because the frequency responses, and roll-off rates, of ported and sealed subs are so different. Ideally, you want to try to match the capabilities of your subs as much as possible, unless you are either willing to accept potential problems with the frequency response, or are willing to dive deeply down the rabbit hole with REW, and an outboard DSP, such as a miniDSP.

For the great majority of users, including myself, the advice to stay with identical, or as nearly identical subs as possible, is both the simplest and best advice."

The only change to that quote which I would make if Mike wants to add it to his general sub guide is to reverse the order of the 2 paragraphs so that the general advice comes first and the expansion of that advice in relation to types of subs etc comes second.

Hi David,

Thank you for your nice remarks and thoughtful suggestions. My original intent with that post was to give us something simple we could use to address the most common questions regarding trim levels. But, you make some good points. It might be a good idea to expand the post slightly to incorporate multiple subs into the discussion. Let me see what I can come up with if I expand a couple of the points on set-up to include multiple subs. I think I will also add some discussion of how Audyssey EQ's single and multiple subs.

Regards,
Mike
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Are there any precautions or changes I should make when doing an Atmos calibration with 4 ceiling speakers? I did the standard 8 points, 3 on seat, 3 at front edge of seating, 2 in back middle. I don't think any were directly under a speaker.
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Are there any precautions or changes I should make when doing an Atmos calibration with 4 ceiling speakers? I did the standard 8 points, 3 on seat, 3 at front edge of seating, 2 in back middle. I don't think any were directly under a speaker.
Hi,

I can't think of any special precautions you should take, but you can always repeat your question on the Atmos home theater owners' thread. I have never been a fan of going behind the listening positions with any of the microphone locations. That only makes sense to me if you have a second row you are EQing for. With a single row, whether it's theater chairs, or a sofa, I would expect to get better results by keeping all 8 mic locations in front of, beside, or just very slightly behind that row. If there is a wall behind the sofa, as there often is, going behind the listening positions would not be advisable. But, that's about the only comment I would make.

Regards,
Mike
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Hi,

I can't think of any special precautions you should take, but you can always repeat your question on the Atmos home theater owners' thread. I have never been a fan of going behind the listening positions with any of the microphone locations. That only makes sense to me if you have a second row you are EQing for. With a single row, whether it's theater chairs, or a sofa, I would expect to get better results by keeping all 8 mic locations in front of, beside, or just very slightly behind that row. If there is a wall behind the sofa, as there often is, going behind the listening positions would not be advisable. But, that's about the only comment I would make.

Regards,
Mike
Yeah I only do 2 right [Edit] behind [/Edit] the back of the chairs, and I actually do have a second row, but I dont really EQ for it. Main concern is front row since the back row is used pretty infrequently. I know they updated so taht positions are only 2ft apart now as well, doubt I followed that though haha.

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post #1308 of 3816 Old 09-30-2016, 11:49 AM
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Yeah I only do 2 right on the back of the chairs, and I actually do have a second row, but I dont really EQ for it. Main concern is front row since the back row is used pretty infrequently. I know they updated so taht positions are only 2ft apart now as well, doubt I followed that though haha.
If you are setting the mic on the chair itself, that is not recommended. You should be using a mic boom or at least a tripod to hold the mic during calibration.

Do I really need to put the Audyssey mic on a tripod or stand?
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post #1309 of 3816 Old 09-30-2016, 11:52 AM
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If you are setting the mic on the chair itself, that is not recommended. You should be using a mic boom or at least a tripod to hold the mic during calibration.

Do I really need to put the Audyssey mic on a tripod or stand?
Sorry that was a mistype, meant "Right Behind" the chairs haha. Yeah I have a both a micboom and tripod. I have been using the mic boom mostly. I think I may recalibrate and bring in the measurements a little. I have 4 chairs in the front row and I think I may have streteched the measurements a little too wide.
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I have edited Post 1296 to add quite a bit of additional material, if anyone wants to make any additional suggestions. It could go on and on, so I'm not looking to get much more detailed. But, most of the information in that post is not specifically included in the FAQ, and I do see a lot of confusion about the gain/trim relationship, and how Audyssey EQ's multiple subs, on both this and other threads.
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Today I redid audyssey and my two subs combined(used y splitter) I got a trim of -11.5
The spl meter shows 72db after audyssey but I bumped it to 80db. In order to achieve 80db I set the trim to -6.5
Is this acceptable? I think I read here so long as the trim by audyssey doesn't exceed -12 and as long as the manual trim is 0 or below you're good.
Correct?

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post #1312 of 3816 Old 09-30-2016, 06:51 PM
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Third, it is desirable to make the subwoofer amplifier send voltage to the driver, rather than having that voltage come from the AVR amp, because the subwoofer amplifier is much more robust and powerful than the amps in the AVR. Therefore, it is desirable to start with a high gain level and a low trim level.
Mike, if the amp in the subwoofer is more robust and powerful than the amp in the AVR, wouldn't it also be desirable to increase gain there (rather than the AVR's trim) after Audyssey calibration if you're not satisfied with the amount of bass Audyssey sets?

The current advice seems to be, start with a slightly high gain on the sub so that Audyssey gives you a low trim. Then, if you don't like how it sounds, increase the trim. However, assuming that the amp on the sub still has some headroom, wouldn't it be better to increase the gain there?

For example, when I do the SW Level Matching at the start of Audyssey and set my sub's gain to hit 75 dB, the dial on the sub is still well below the halfway point. (It's basically at about 1/3.) After calibration, Audyssey gives me a trim of -6. Rather than boost that to, say, -3 or -2, why wouldn't I leave the trim at -6 and turn up the gain on the sub instead?

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post #1313 of 3816 Old 09-30-2016, 08:07 PM
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Mike, if the amp in the subwoofer is more robust and powerful than the amp in the AVR, wouldn't it also be desirable to increase gain there (rather than the AVR's trim) after Audyssey calibration if you're not satisfied with the amount of bass Audyssey sets?

The current advice seems to be, start with a slightly high gain on the sub so that Audyssey gives you a low trim. Then, if you don't like how it sounds, increase the trim. However, assuming that the amp on the sub still has some headroom, wouldn't it be better to increase the gain there?

For example, when I do the SW Level Matching at the start of Audyssey and set my sub's gain to hit 75 dB, the dial on the sub is still well below the halfway point. (It's basically at about 1/3.) After calibration, Audyssey gives me a trim of -6. Rather than boost that to, say, -3 or -2, why wouldn't I leave the trim at -6 and turn up the gain on the sub instead?
Hi Josh,

That method would work perfectly well. It's absolutely the same thing as far as the sub amp is concerned. It just isn't as convenient for the user. Many sub gains are on the back of the sub, and not easy to get to. And, if the gain control isn't digital, it's difficult to know just how much boost you are adding, or to easily control the increments of gain. The AVR trim gives you half decibel increments that you can easily keep track of.

For some movies, you might want to increase the sub boost, and for others you might want to turn it back down, so that adds to the inconvenience factor. And if you are using multiple subs, on a Y-connector, you would have to be careful to add exactly the same amount of gain to both subs, so that they remain level matched, and then subtract exactly the same amount if you wanted to change back. Using the trim control in the AVR insures that the sub levels on two Y-connected subs will increase or decrease by exactly the same amount. So, it's really just an issue of efficiency and convenience for the user.

When you increase the gain, prior to running Audyssey, you make a deposit in the subwoofer amp bank that I referred to earlier. Now, instead of starting with a trim level of -3 or even -6, you are starting with a trim level of -9 or -11. If you want to add +9 or even +11db of trim, you can do it, without ever leaving your chair. And, if you wanted to go even louder than that, the option to increase the gain on the sub(s) would still exist. But, starting with a high gain, and a strongly negative trim, just makes it far easier to make incremental adjustments, while keeping track of exactly what you are doing.

I hope that all makes sense.

Regards,
Mike

One additional thought concerns the sub headroom you mentioned. If the sub doesn't have plenty of headroom, you won't be able to get a very low trim level, no matter where you set the gain. So, it will be pretty easy to tell. But, if you can get a good negative trim level, it's far easier to use your sub amp then, by making trim adjustments in your AVR.
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One additional thought concerns the sub headroom you mentioned. If the sub doesn't have plenty of headroom, you won't be able to get a very low trim level, no matter where you set the gain. So, it will be pretty easy to tell. But, if you can get a good negative trim level, it's far easier to use your sub amp then, by making trim adjustments in your AVR.
Thanks, Mike. That all makes sense.
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post #1315 of 3816 Old 10-01-2016, 12:02 AM
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... I think it's important to identify your short and long-term bass goals as you buy. To me, that's the single most important lesson I have learned.

... give you improved SQ, and still have sufficient output for your requirements.

I hope this helps!

Regards,
Mike
Hi Mike, thank you very, very much! You have really helped me!


Jim
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post #1316 of 3816 Old 10-01-2016, 06:14 AM
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Hi Mike, thank you very, very much! You have really helped me!

Jim
I'm really glad if I did, Jim! Please do me a favor, though. Let us know what you decide to do, and how it works out for you. Sometimes, these stories end in the middle.
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post #1317 of 3816 Old 10-01-2016, 11:05 AM
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Today I redid audyssey and my two subs combined(used y splitter) I got a trim of -11.5
The spl meter shows 72db after audyssey but I bumped it to 80db. In order to achieve 80db I set the trim to -6.5
Is this acceptable? I think I read here so long as the trim by audyssey doesn't exceed -12 and as long as the manual trim is 0 or below you're good.
Correct?

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That sounds perfect to me. I really like to start with -11.5, if I can hit it, in order to have the maximum amount of upward trim adjustment. At -6.5, you are using just under half of your total available headroom (without additional gain adjustments). So, you still have plenty of room if you ever want to open it up even more sometimes.
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post #1318 of 3816 Old 10-01-2016, 11:17 AM
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That sounds perfect to me. I really like to start with -11.5, if I can hit it, in order to have the maximum amount of upward trim adjustment. At -6.5, you are using just under half of your total available headroom (without additional gain adjustments). So, you still have plenty of room if you ever want to open it up even more sometimes.
Sounds good thank you

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post #1319 of 3816 Old 10-01-2016, 03:16 PM
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Question about Audyssey XT32 measuring positions. I have a rather small room in which the couch (which includes the MLP in the middle) is in a 7-foot equilateral triangle with the front mains. There is about three feet between the back of the couch and the wall behind. The L and R surrounds are in the back corners of the room and aimed at the MLP. There are never more than two listeners in the room.

The drawing from the Audyssey website would indicate that measuring positions 7 and 8 should be on top of the couch behind the head of the listener in the MLP. But is this the best idea? I'm open to other ideas on where to place the mic during calibration?


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Question about Audyssey XT32 measuring positions. I have a rather small room in which the couch (which includes the MLP in the middle) is in a 7-foot equilateral triangle with the front mains. There is about three feet between the back of the couch and the wall behind. The L and R surrounds are in the back corners of the room and aimed at the MLP. There are never more than two listeners in the room.

The drawing from the Audyssey website would indicate that measuring positions 7 and 8 should be on top of the couch behind the head of the listener in the MLP. But is this the best idea? I'm open to other ideas on where to place the mic during calibration?


Hi,

I can get things started. I have never quite understood going behind the head for a single row of seating. I would suggest bringing 1, 9, and 10 within 6" of the back of the sofa where your head would be, and as close to the middle of the ear canal in height as possible. (If you prefer, that could be 1, 2, and 3, but I still might not spread them too far apart.) If the sofa is leather, or a smooth fabric, I would recommend draping a thick blanket or absorbent towel over it. Then, I would pull in 4 and 6, to correspond to 9 and 10 in width, and bring 4, 5, and 6 back a little toward the sofa--maybe out about 20" or 24" from mic position 1.

The last two positions could be 9 and 10 as they are shown in the diagram, or you could really drill down on the MLP at the center of the sofa. I like to concentrate on the MLP, so I do the last two mic positions no more than 12" apart (6" out from mic position 1 to each side) and I elevate the mic by 2" or 3". So, six of the 8 positions form a kind of box around and ahead of the MLP, and are precisely at ear level. And then, the last two concentrate a little more on the MLP, and go a little higher. That seems to help with the overall response, and we do sit up straighter sometimes.

I hope this is helpful!

Regards,
Mike

Last edited by mthomas47; 10-01-2016 at 04:35 PM.
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