Anthem MRX Receivers - 300, 500, 700 Owners Thread & Tweaking Guide - Page 193

First you have to look at the crossovers that get Uploaded as the crossover for the sub my be different from the "cutoff" ARC displays. As Anthem said, the two of them are different.

It may be that the sub crossover is higher than 80Hz even though ARC is putting less resource into correcting the sub above 80Hz.

You can check the impact of all this by looking at the green, Calculated curves for Center and for the Sub at and below the crossover frequency for Center. ARC is rolling off output to Center below that and steering that audio to the sub. The question is, is the sub there to catch it or is its output too weak up there?

First find the basic volume level of the ARC solution. That's the flat part of the main speaker Targets curves to the right of the crossover frequencies. Evaluate everything with respect to that basic volume level.

Now look at the green Calculated curve for Center and note how it drops off below 100Hz. The question is, where is AT 100Hz? It should be right about the basic volume level. EXCEPTION: The effect of Room Gain is to raise the output in the bass frequencies. A +3dB Room Gain gives you a shallow hump of slightly higher output in the bass that's +3dB over the basic volume level. Depending on how high the crossover is for a speaker, the "expected" Calculated result at the Crossover should be at the basic volume level OR a little bit higher due to the application of Room Gain.

Now look at 1/2 the crossover frequency for Center. The Target curve for Center should have dropped off -12dB from its volume at the Crossover. (The green, Calculated curve for Center should be close to the Target curve.) Any Center frequencies down there will have to be handled by the Sub. That's what we mean by bass steering. It's that range from the Crossover frequency to one octave down (1/2 the crossover frequency) that's important.

Now look at the green Calculated curve for the sub. At 1/2 the crossover frequency for Center the sub's response should be the basic volume level PLUS the Room Gain lift. That shows that the sub is able to handle steered bass coming in from the Center channel down there without problem.

Now shift right and look at the green Calculated curve for the sub AT the crossover frequency for Center. At that frequency, almost all the Center channel output is still being sent through the Center speaker. But you are just starting to get bass steered to the Sub. So what does the sub's response curve look like? If it is at or above Center at that frequency then you are clearly in good shape. Whatever goes to the sub from the Center channel below that, the sub is there to handle.

If it is, say, -3dB (or worse) below where Center's curve is, then you have a hole. As bass starts to get shifted to the sub from the Center channel for frequencies below that, the sub isn't there to catch them. As you go further down in frequency, the sub's response improves and the hole is gone.

Why would ARC do that? Well ARC measures what it thinks your sub and your Center are capable of doing and does the best it can to close any such hole between them without over-stressing either of them. ARC has some built in limits -- such as no more than +6dB boost to any speaker at any frequency -- to protect the amps and speakers.

If ARC finds a problem trying to match the sub with any of your speakers it gives priority to making the LF/RF/Sub combo work best.

So what to do if you have a hole? Well of course you could replace the sub with one that has better output in high bass, or the Center with one that has better bass output itself.

But before you do that, be sure to check that you are getting the best you can out of the speakers you've got.

First, play some stereo music with bass content using a Mono audio mode so all speakers get the same thing. Now go put your ear up close to the woofer in Center and make sure audio is coming from it. It is VERY common for people to have a Center speaker with a broken woofer. If there's nothing coming from the woofer then the bass your center is producing is actually coming from the low end of its mid-range cone. Fix the speaker.

Next double check to make sure you don't have an internal crossover active in your sub. An internal crossover will artificially attenuate the high bass output of the sub -- i.e., you aren't letting the sub show off its chops in high bass. Disable any such internal crossover or crank it up to the highest possible frequency to get it out of the way as much as possible.

Be aware that setting a "THX" mode in a sub may impose an 80Hz internal crossover despite whatever you've done with the sub's other crossover controls. So don't use that THX mode.

NOTE: The whole idea is to let ARC do ALL the crossover processing. That's why it is safe, and necessary, to bypass any crossover built into the sub.

Third, try repositioning the subwoofer -- watching what happens to its output using the Quick Measure tool in ARC. Quick Measure will show you a chart, updated live in real time, of the raw, uncorrected output of any single speaker. What you are looking for is a new position that gives the sub better output in the high bass without producing too many problems elsewhere. For some subs, such as the Paradigm Servo subs, the impact of the Servo correction in the sub may reduce high bass output if the sub is positioned in a corner, for example. Moving the sub to a side wall or at least different distances from the two walls making the corner can yield a big improvement in its high bass.

Any such changes will require you re-measure for ARC.
--Bob

Look for the measured line (red) to track close to the Target curve (dotted line). This will allow ARC to come up with the best correction solution (green) which, in the best case, would be superimposed on the target curve.
John

So do you guys leave everything on auto or switch it around. I set my sub setting to flat yesterday and the chart looks quite a bit different. Instead of having the low end dip, it was corrected to be much closer (although slightly below) the target dotted line. I will try and post it when I get home but is this what it should look like?

Bob,

thanks for the comprehensive reply. It is most appreciated.

I understand all the details and my speakers are fine and their placement is optimal for the room layout. The subwoofer has been fine-tuned using its built-in single parametric filter with Quick Measure to eliminate a big peak that I caused by placement as I didn't want any nulls in the frequency response so that ARC would be in a much better place.

My question is where do I see the crossovers that got uploaded? When I look in Bass Management I see the settings from the Targets response cutoffs that got uploaded. There is never (or at least I haven't seen it) any deviation from what the targets were (either auto or personal) and what the Bass Management is. If they weren't the same thing than there should be a difference. Hence my confusion.

Cheers.

Tony

They don't appear anywhere that I know of with the MRXs or the pre/pros but they are there.
John

Hi John,

okay, that is what I was looking for. Not that I have a problem with Anthem's approach but they could be a little clearer in their explanations and in the Bass Management part of the Setup screen. It always makes you wonder what the crossovers are when ARC is shut off?

Cheers.

Tony

The uploaded crossovers from ARC are what appear in Bass Management in the Anthem after the Upload. ONLY THE SUBWOOFER crossover will ever have a value different from the "cutoff" value shown in ARC's Targets window.

For some folks, even their sub's crossover will match its cutoff. Since the MRX has fewer available crossover choices than the D2v, this is more likely to be the case for an ARC setup in the MRX. I.e., ARC found no advantage in using different values for the two of them given the choices available.

Just as with volume trims, any prior crossover values in the Anthem get replaced by the values ARC Uploads.
--Bob

Bob,

thanks! That is an informative post and will definitely help alleviate the confusion

Cheers.

Tony

Thanks for the link. I did not order this one before. I ordered just now the high quality cable you mentioned.

It is too expensive in Best buy to buy 16 feet audioquest for 99 dollars.

Sorry for quoting an old post but the 43.9-watt measurement, much lower than our conservative rating, still comes up every so often in discussions despite the fact that Sound&Vision subsequently measured 71W for its April issue.

The August 2011 issue of Home Theater Magazine is on newsstands and has a review of the MRX 300. In that, the all-driven measurement is 56.3W at 0.1%, and 70.9W at 1%. (That's more like it...)

Thanks Nick,

It was always clear to those of us using an MRX that the origional # made no sense.

I mean if Home Theater Magazine measured 56.3W at 0.1%, and 70.9W at 1% on the MRX 300... their earlier quote of 43.9W on the MRX 700 just doesn't even make sense

I wonder if it was simply a misprint or something? Do you know if Home Theater Magazine ever posted a correction somewhere?

Didn't see one. I wanted to do something about it but by that time word had really gotten around and I'm thinking, how often are little notices after the fact seen anyway?

So I changed the sub to flat and recalculated. I know my sub has a deficiency at the lower end but since it is in-wall, it can't be changed. Just trying to maximize what I have. Will changing to this make a difference or will it just stress the sub too much. I am basically clueless at this so I apologize if this change is totally off.

Thanks.

Try it. I don't know what your sub specs are, so hard to know whether you are stressing it.
John

From earlier post #5432

How much of a change does flat make? If not much, don't use it, if a lot, make sure you have low freq. protection built in to prevent sub damage.
John

Sorry to post the same thing twice, but since nobody reacted I thought it might have gotten lost in the other discussion. So there I post again the answer I got from Anthem concerning the sound and Vision test:

We conducted a frequency response test on the MRX 700 with a 96 kHz / 24-bit signal via HDMI at -20 dBFS with volume set to -10 dB. The results were +/-0.1 dB for 20 Hz to 20 kHz and +/- 0.5 dB for 10 Hz to 32 kHz.

With regard to the linearity test, we are also seeing an increased deviation below -80 dB. The conclusions that it is a least-significant-bit flaw or a math error are, however, unjustified. We feel it is more likely that the signal has dropped into the noise of the system and cannot be adequately tracked.


My interpretation: According to Anthem the measuremen of frequency response at 24&96 was simply wrong (I tend to agree, since they also got the 7 channel watt output wrong, as the post above show) and they draw other conclusions from the -80dB deviation.

When listening to MRX 700 in the Anthem Logic Music mode in the 5.1 format, the surround rear speakers seem to output fuller sound than the main front speakers. Is't normal? I would think, fuller and richer sound would come from the 2 main front speakers. Thanks for all your feedback.

It is not normal, I think. In my case, Anthemlogic music provides some ambience from the rear, but nothing intrusive. Anthemlogic cinema provides more sound from the rear.

I will take a guess and say it's normal. When you play music Anthem Logic Music it will use your surrounds to fill the room with constant output from them unlike when in Anthem Logic Cinema in which your surrounds are not always producing sound. So maybe it's the constant output of sound that is making them seem like they have a fuller output

Those who have listened to the Anthem Logic Music, what is your verdict: do the rear surround speakers sound louder than the main front speakers when listening to music?

It is supposed to be subtle, that is the intent.
John

Hanser, thanks for querying Anthem. Unfortunately, Anthem's answer is a poor one on several counts:

1. Noise would cause a positive linearity error, not a negative one, as Sound and Vision measured. As it stands, the MRX series has the low level linearity performance of a circa 1990 CD player. See an example graph below:



http://www.stereophile.com/content/n...r-measurements

2. Even if noise were somehow the cause, it should not swamp the output below -80 dBFS. That would be 13-14 bit equivalent performance, unacceptable for components the caliber of the MRX series.


Sound and Vision did not get the seven channel power output measurement "wrong." You may be thinking of Home Theater:

http://www.soundandvisionmag.com/con...-av-receiver-1
http://www.hometheater.com/content/a...-labs-measures

And, unless experimental error can be uncovered, Home Theater did not get its measurement "wrong." Home Theater simply got a different result. That a measurement of a component does not match expectations for that component or even experience with that component does not alone make the measurement inaccurate.

AJ

No they don't, although it may seem that way with some material depending on how it is mixed.

As I have said before ALM sounds simply fantastic with my set up.

My rears are subtle in Anthem Logic Music. Definitely not louder than front.

You first mentioned "Fuller sound", that is different from louder. They should not be louder. Are you confusing fuller with louder?

What I meant is I can hear the rear surround sounding louder, like revealing more sonic details, like the drum beats, higher bass, better vocals, etc. The other question I have is when watching movies in the Anthem Logic Cinema, are the rear surround speakers supposed to sound louder than in the Anthem Logic Music mode? Thanks.

I do not think it is normal. On occasion I have had this happen to me. The surrounds seem to be playing the main content instead of just filling in background. It does not happen all the time. Sometimes switching between movie and music mode or different inputs helps resolve the issue.

You could also have an issue with music that is out of phase... that will cause a matrix decoder (like AL Music) to send material to the surrounds..

Do you have any handshake issues with current beta?