why do auto setups set fronts to large

P

puck11

Enthusiast
i have a denon 4306 which is great but why does the audessey setup make my polk r20 6.5 in woofer large i believe i blew both woofers because of that good thing still wrnty. i had changed to small in manuel setup but found out to late it does not change the audessey to small . i like the sound from the audessey but ijust copied all the settings to the manuel eq distance and level and made fronts to small hopefully when i get my polks back it does the trick
 
Adam

Adam

Audioholic Jedi
That is a great question! I've wondered that myself. Hopefully somewhere here has the answer.
 
M

MDS

Audioholic Spartan
The auto-setup routines play test tones and measure the response. If the -3dB point (the frequency where the amplitude is down 3 dB) is below 80 Hz they are generally considered Large by the auto-setup.
 
mike c

mike c

Audioholic Warlord
below 80? thats a bit high, that will only exclude satellites but include pretty much all the bookshelves.
 
the grunt

the grunt

Audioholic
I have seen the 80Hz figure also mentioned in a couple reviews however I don’t know the source they are using. Also I know from experience with my Denon 2807 and now reading much about Audyssey on the internet that many people have issues with it setting speaker sizes. On my system it often set my towers to small and the smaller center and surrounds to large. So before I stopped using it I always checked the parameters it set before playing anything.
 
Seth=L

Seth=L

Audioholic Overlord
I have found some of the settings will need to be changed after auto-setup, the settings have never been ideal for my system when I used them.:cool:
 
mike c

mike c

Audioholic Warlord
hehe, instead of an auto setup mic, there's an auto "estimate" camera.

takes one look at the user ... and then concludes: "this one's small" , "holy crap, he's packing"
 
N

Nick250

Audioholic Samurai
This the voice of experience speaker here. Run Audyssey Auto EQ and then exit the auto setup page. Go back into speaker setup and change all your speakers to small and the cross over at 80Hz, except the LFE which you make sure is at 120 Hz. I had a number of exchanges with Chris from Audssey about this and he wrote the following:

http://www.avsforum.com/avs-vb/showthread.php?p=7969145#post7969145

Here is a list of tips based on several discussion in this and other forums about MultEQ. I will add to it from time to time as new questions come up. Some additional information can also be found on the Audyssey website.

Best regards,
Chris
CTO, Audyssey Laboratories



Microphone Placement

• The microphone has been calibrated for grazing incidence and so it must point to the ceiling during calibration. Any other orientation will produce incorrect results.

• The microphone response has been calibrated to match (on average) the response of an industry-standard ¼” instrumentation microphone. It is critical to use the microphone that came with the receiver and not one from another model that may have a different calibration curve.

• It is also important to place the microphone on a tripod or other stand so that it is at ear height. We strongly recommend against holding the microphone in your hand because this can give rise to low frequency handling noise that will cause the MultEQ filters to compensate by cutting those frequencies. Furthermore, it is not recommended to place the microphone on the back of the couch or recliner. If a tripod is used, care must be taken to ensure that the microphone is placed at a height just above the seat back so that reflections from the seat do not cause problems at higher frequencies.

• The first microphone position is used to calculate the distances to each loudspeaker and subwoofer and set the delays. It is also used to measure and set the trims. So, it is important to place the microphone in the main listening seat for the first measurement.

• MultEQ measures the background noise level in the room before playing the test signal from each speaker. For the measurements to be valid, the signal to noise ratio must be above a certain threshold. If it is not, the test signal from that speaker will repeat at a higher level. If the noise in the room happens to be higher during some of the speaker measurements, then the test signals from those speakers will sound louder than the test signals from the other speakers. This does not affect the calculation of trim levels. If the room noise is too high even after the test signals increase in level, then an error message will be displayed warning the user that measurements can not be completed.

• After the first position is measured, MultEQ measures other positions in the room around the listening area. These do not necessarily have to be in each individual seat. The idea is to capture as many points around the listening area as possible so that the acoustical problems that affect the quality of sound within that area are minimized.

• For example, we recommend taking 3 positions on the couch facing the TV and then 3 more positions about 3 feet in front of the couch and parallel to the first three. Measurements up against the back or side walls should be avoided.

• Some loudspeakers have rather problematic responses when measured off-axis (i.e. more than 15° away from the imaginary straight line that points to the listening position). In these systems, measurements taken too far away from the center line will show a reduced high-frequency response that may result in overcorrection and thus overly bright sound. Although it is difficult to predict which type of loudspeaker will have these off-axis problems we have most often observed them in poorly-designed multiple-driver arrays that exhibit very high off-axis lobing. In these situations we recommend a tighter calibration pattern centered around the main listening position and making sure that the mic is not placed in extreme locations and certainly not outside the plane of the front main speakers.

Checking the Results

• Once MultEQ calibration is complete the results are stored in the receiver memory.

• It is important to activate MultEQ by selecting one of the target curves. This is not performed by default after the calibration is finished and must be selected by the user. In a THX system we recommend using the “Flat” setting that allows the re-equalization to work as intended. In other systems, we recommend “Audyssey” for movie playback and “Flat” for music playback. Unfortunately, the music industry does not have any mixing standards like the movie industry so some music program material may sound better with the “Audyssey” setting. “Front Align” also uses the Audyssey process, but it does not apply the filters to the two front loudspeakers. “Manual” is not an Audyssey setting and does not use MultEQ filters. It is a simple parametric equalizer and will be subject to all the limitations that come with parametric EQ.

• Small vs. Large speakers. This is the most commonly discussed topic by MultEQ users. The first thing to understand is that it is not a personal insult to your system if your speakers were detected as “Small”. It simply means, that in the room they were measured the – 3 dB point was detected at 80 Hz or above. This may happen even if the manufacturer’s spec shows that the speaker is capable of playing lower. In fact, there are several benefits at crossing the speakers over at 80 Hz that have to do with power handling and headroom in the bass region that will be handled by the subwoofer amplifier.

• The second most common question also relates to Small vs. Large. In the Denon receivers, MultEQ will designate as “Large” any speaker that has a –3 dB point below 80 Hz. For non-THX speaker systems this is an arbitrary definition that often causes confusion. All it means is that the speaker will not be bass managed unless the user tells it to be. Because Audyssey is not in charge of bass management, we have to abide by the manufacturers’ rules and simply report the information found by the measurements to the bass management system.

• In situations where the speakers do not play significantly below 80 Hz, an additional step must be taken to make sure that there is no loss of bass information. The user must set the speaker to Small manually so that bass management is performed properly.

• Polarity: MultEQ checks the absolute polarity of each loudspeaker and reports it to the user. This is simply a report and does not affect the subsequent calculations in any way. It just asks you to check the wiring to make sure it is connected properly to each speaker. Sometimes we get false alarms. This is usually because the speaker has a driver (usually the mid-range driver) wired out-of-phase intentionally to make up for some problems at the crossover region. If a phase warning is shown, it is not a cause of alarm. Simply check the cables and hit “Skip” if everything is fine. Again, this does not have any effect on the EQ results.

• Subwoofer distance: in many active subwoofers it is not possible to defeat the low-pass filtering. That means that the pre-pro bass management filters will be on top of the low-pass filters inside the subwoofer. The built-in low-filters introduce a delay to the signal coming in (because they have poles). This delay is seen by MultEQ as acoustical delay and is reported in the results. That is why sometimes the subwoofer distance is reported to be longer than the physical measured distance. The setting should not be changed because the blend between the sub and the satellites has been designed based on this time delay.

• The design constraints for MultEQ were that it (1) must fit within a small portion of the DSP so that other processes can also run and (2) it must use FIR filters because of the well-known artifacts that IIR filters cause particularly in the time domain response. As it turns out, these two requirements are contradicting. In order for FIR filters to be effective and capable of correcting to low frequencies, they must consist of several thousand coefficients (taps). The problem is that the CPU power required increases with the number of taps, hence the dilemma. What we did at Audyssey was to come up with a different way to partition the frequency axis so that we can use fewer taps and yet not completely give up on low frequency resolution (and therefore low frequency correction). This allows us to take a 512 tap filter that would normally have a resolution of 94 Hz (meaning that any peak or dip narrower than 94 Hz would be missed) and significantly improve its resolving power. The resolution of the filter actually varies continuously with frequency and starts at around 10 Hz. Does this mean that MultEQ can correct an arbitrarily narrow peak or dip at 30 Hz? Of course not. The reality is that in the MultEQ XT version found in receivers, we can correct broader features below 100 Hz better than narrow ones. For example, a lump that is half an octave wide at 50 Hz can be fixed. A narrow dip or peak that is 1/3 or 1/6 octaves wide and centered at 30 Hz will be improved, but not eliminated.

• The on-screen display in the receiver has very limited graphics. Therefore it is not possible to really show what the MultEQ correction filter is doing at all frequencies. It appears to only be operating on 9 bands like a parametric equalizer, but this is not the case. What is shown is a very crude approximation to the MultEQ correction and it should not be used to read exact values of cut or boost at the 9 frequencies shown.

• Furthermore, there is no display for the subwoofer filter. This doesn’t mean that there is no subwoofer correction. It was not added to the display because of interface and memory considerations.
Report Post
 
jcPanny

jcPanny

Audioholic Ninja
Mic frequency response

I suspect the the frequency response of the cheap Mic included with most receivers is limited to the 60-80 Hz range. If a speaker can play these frequencies, then it is considered "LARGE". This would also explain the limitations of most systems to EQ the subwoofer frequencies below 80 Hz.
 
P

puck11

Enthusiast
nope

even in man sp setup i change to small then i check audessey settings still on large cannot change thats why i blew speaks
 
E

edmcanuck

Audioholic
i have a denon 4306 which is great but why does the audessey setup make my polk r20 6.5 in woofer large i believe i blew both woofers because of that good thing still wrnty. i had changed to small in manuel setup but found out to late it does not change the audessey to small . i like the sound from the audessey but ijust copied all the settings to the manuel eq distance and level and made fronts to small hopefully when i get my polks back it does the trick
1) Generally, you want sub-80Hz sounds to come from the sub so if your speaker can play sub-80Hz with <3dB deviation then they are considered large.

2) As has been told to you in your other thread (and you really only needed one), when you change the speaker size in your Speaker Setup section after saving and closing the Audyssey section it is changed. The Audyssey section merely reflects what the Audyssey/self-calibration section decided on. It is not what is being used if you've changed it. Conversely, changing it in the Speaker Setup does not change what Audyssey measured.

3) I promise that you didn't blow a woofer because your speaker was set to large. Woofers get blown because people play their music at stupid levels.

4) If you copied the Audyssey setting into the Manual EQ then you're no longer using Audyssey. Read the manual.

jcPanny said:
I suspect the the frequency response of the cheap Mic included with most receivers is limited to the 60-80 Hz range. If a speaker can play these frequencies, then it is considered "LARGE". This would also explain the limitations of most systems to EQ the subwoofer frequencies below 80 Hz.
That "cheap" mic is $70 which is quite a lot for a simple setup mic. It is precisely calibrated and has a lower response point of 12Hz +/- 0.1dB. The difficulty EQ'ing a subwoofer has to do with bass response in a reflective room and the difficulties working with the lower part of a logarithmic response curve. It's large if it can handle any frequencies that are typically expected of the subwoofer... that's it.
 
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N

Nick250

Audioholic Samurai
even in man sp setup i change to small then i check audessey settings still on large cannot change thats why i blew speaks
Any manually made settings in the receiver setup area made AFTER you run auto EQ such as large/small, crossover settings etc. overrides the Audyssey setting even though you don't see it in the Audyssey setup screen.

Nick
 
T

trnqk7

Full Audioholic
Audyssey Help on 2807

I have a question about the Audyssey on the 2807-my fronts have 10" woofers and using an old Onkyo receiver, would hit down to about 60hz pretty well (ie, would knock things off the speaker if placed on top). After upgrading to the 2807 and running the Audyssey, it sets them to large, as I would expect, but in checking the eq settings, shows that at 63hz, it applied a -20db tweak to them. As a result, I get zip bass from speakers that I know are capable of providing decent bass at least (not subwoofer territory, but still). What I end up doing usually is copying the Audyssey settings to the manual eq and bumping the 63hz and above back to at least -3db to get back some usable bass. I then leave the speakers set to large, xover at 60hz for them and set the sub xover to 80hz.

I am wondering a few things-

1. Why does audyssey lower the db level SO much on these relatively large speakers?

2. If left set to large, does setting a xover point on the 2807 actually do anything? I suspicion it does, but am not sure.

3. And finally, I've noticed, that even though I copy the Audyssey settings, as mentioned above in this post, it doesn't capture everything. The straight up Audyssey settings sound better for everything BUT the bottom end. It sounds much "harsher" and overly loud after copying the settings (not in the bass region though, more in the midrange).

Any thoughts?
 
M

MDS

Audioholic Spartan
1. Why does audyssey lower the db level SO much on these relatively large speakers?
Audyssey is attempting to make the frequency response match some target curve (I believe there are a few targets you can choose). It's not related to the fact that the speakers are large. The room and speaker placement within it is causing a huge spike at 63 Hz so Audyssey EQs it down to remove the peak.

2. If left set to large, does setting a xover point on the 2807 actually do anything? I suspicion it does, but am not sure.
Nope. By definition the Large setting means the speaker should get a full range signal. No part of the frequency spectrum going to the channels set to Large will be redirected to the subwoofer. If you don't have a subwoofer, any channels set to Small will have the bass below the xover sent to the Large speakers. If the receiver has a 'double bass' type feature then the bass below the xover for the channels that are set to Large will go to the subwoofer but the speakers themselves still get the full range - hence double bass - both the Large speakers and the sub are playing the bass.
 
TLS Guy

TLS Guy

Audioholic Jedi
Blown speakers

I really doubt your Polk speakers were blown just because they were set to large. After all if you had bought them for a standard stereo set up, no sub, they would be playing large, wouldn't they? Unless of course you played them at deafening levels I fail to see why they should be damaged.

I suspect that this auto set up has not just set the speakers to large, but also equalized the bass. If you equalize the bass of a ported enclosure you are likely not only to damage the speaker but also add gobs of distortion. If they just increased the bass power at any frequency by 3db, they are doubling the power to the driver at that frequency.

I can tell you this much, the whole basis of that auto set up sound bogus to me and a recipe for what you experienced with your Polks.

There should be absolutely nothing wrong with setting any well built speaker with an F3 below 80 Hz to large. In fact if it is a good speaker, splicing the sub roll off to match the natural roll off of the left and right speakers, is quite likely to give the beast result. It will be the solution likely to have the least phase, time and group delay problems

As for this idea that you need a different Eq for music and movies, that is an idea, that I find preposterous. My audio visual preamp has those settings also, which the manufacturer advises to be used. I find anything but the flat music setting, sounds just plain awful. It just ruins the whole effect of my beautiful speaker system which when playing movies produces uncanny realistic natural speech, and the sounds of everyday life unbelievably realistic.
I certainly don't want it to sound like any cinema I have been in.

I would try your rig without all that auto set up, leave off all Eq and see how it sounds. Set you speakers to large and then small and see which sounds best. If there is no Eq, I see no reason why your speakers should suffer damage.
 
F

fmw

Audioholic Ninja
I agree with TLS. Audyssey didn't destroy your speakers. Playing them too loud did. What breaks in a speaker driver is the voice coil by getting over heated because too much current is applied to it. You applied too much current to it.

I have an Onkyo receiver. It does a very adequte job setting levels for the 6 channels I use. I checked it with an SPL meter after completion and found the setup satisfactory. My main speakers are deficient in bass so I turn up the sub just a hair from flat after Audyssey is finished to compensate. If I remember correctly, telling Audyssey that my speakers were small or large was an option in the menu. Perhaps I've forgotten.

At any rate, I just wanted to concur with TLS that Audyssey wasn't the culprit.
 
T

trnqk7

Full Audioholic
I would tend to agree with TLS and fmw as well after some testing. Although I ended up tweaking the eq curve Audyssey gave me, when tested with and SPL meter, it was pretty dead on as far a levels. I guess I just like to have a little more bass than Audyssey and for my fronts to actually work a little, so I "fixed" the dip at 63hz to my liking. If anything, Audyssey seems to be a little on the conserative side as far as settings go in my experience.
 
H

hclarkx

Audiophyte
Inadvertent bass traps

I would tend to agree with TLS and fmw as well after some testing. Although I ended up tweaking the eq curve Audyssey gave me, when tested with and SPL meter, it was pretty dead on as far a levels. I guess I just like to have a little more bass than Audyssey and for my fronts to actually work a little, so I "fixed" the dip at 63hz to my liking. If anything, Audyssey seems to be a little on the conserative side as far as settings go in my experience.
There's not much to add here, but in fact Audyessey EQ can place some added stress on your speakers. It's not something to be shunned though. It's called room correction and is desirable. Usually, you have room gain and more bass than a flat target curve would give and you notice a loss of bass when you Equalize. If you like more bass you can crank up the sub gain, or better yet, use the bass control in your pre-pro or receiver to boost the bass. That should give a smoother boost starting at several hundred Hz and getting larger until 30 or 40 HZ. Just pushing up the sub gain gives a bit of a step increase across the sub range and thus not as good a blend as the tone control.

The increased speaker stress can occur if you have a "bass trap" in the listening room. This might be a hallway or opening to another room such as a kitchen. That "cavity" will have a certain frequency and Q and act as a trap. If you measure room response with something like the REW software, you can identify such conditions. That trap will give you a dip in response that Audyssey will try to correct by pushing up the gain in that frequency range. The result will be a speaker that is working harder at that frequency (though it may be working less hard at other frequencies where the opposite is happening).

Another cause of need for boost at some frequency is an unfortunate speaker placement that gives a dip in amplitude at your listening position. Unfortunately many rooms and speaker placements do this. For instance, if your speakers are on one wall, the sound will bounce off the opposite wall. If you are sitting between the two walls, at some frequency the sound bouncing off the back wall will hit your ears out-of-phase with the direct wave causing a dip. The dip will be limited because of decay in the sound traveling the longer path but still can be 20 db or more. Audyssey will try to correct that and work the speakers harder at that frequency to get you closer to flat at your listening position

While such issues can result in speaker damage, if they do, the speakers were surely being run near their breaking point already. I.e., this is a secondary effect that would only cause failure if you were operating very close to failure already.

My feeling is that a 6.5 inch woofer is not up to movie level listening in anything but a fairly small room with few bass problems.

Harrison
 
TLS Guy

TLS Guy

Audioholic Jedi
I remain highly suspicious of those auto EQ programs. I think generally you are better off doing it by ear. Those programs can do unexpected and undesirable adjustments. They can go and put a 10 db EQ, and if they do you are calling for a tenfold increase on power at that frequency. There are two problems with this. The first is driver damage by thermal means and exceeding xmax. The other problem is that ported designs to not take well to EQ, unlike sealed. The ported enclosure will decouple and not greatly increase output as EQ is applied, but will increase distortion markedly and be at risk of damage. The problem is the EQ program not sensing the increased output it is looking for, just goes on increasing the EQ. This is not good engineering, and hazardous to speaker longevity.

Your point about bass leakage and cancellation are well taken.
I do think part of the problem for users wanting more bass, is that in my opinion the vast majority of speakers suffer from midrange shout in varying degrees, and I think this leads to excessive bass as a way of masking the shout.

As far as small drivers, are concerned, there are good small bass mids that have robust motor systems. The Dynaudio and Morel and others do. These do for instance.

http://www.madisound.com/catalog/product_info.php?manufacturers_id=173&products_id=782

One advantage of metal cones is they they conduct heat away from the voice coil.
 
Hi Ho

Hi Ho

Audioholic Samurai
I have setup many systems using the auto setup feature in receivers from Yamaha, Denon, Pioneer, and Sony. I wouldn't bother with Sonys' auto setup. It doesn't work well. The others seem to work quite well. I like Yamahas' setup best because it allows me to choose the parameters set by the auto system. I can tell it to ignore speaker size and crossover settings so I can do it myself.

I have found that it is pointless to set levels and distances manually since Denon, Yamaha, and Pioneer have that down. They get it pretty much spot on. I can't really comment on EQ as far as acurracy but I can say that I have never seen a receiver attempt to boost any frequency significantly. They seem to do it the proper way and bring down the peaks.
 
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