Anthem MRX Receivers - 300, 500, 700 Owners Thread & Tweaking Guide - Page 460

SVS 25-33pci cylinder sub (or 25-31pci.. can't remember the exact number.)

Supposed to be rated down to 20hz

Look at the subs amp and see if there is a crossover bypass. If not turn the crossover up as high as it will go to get it out of the way. It looks like it's rolling off due to the subs filter being engaged. Then rerun ARC.

I don't think the foam would make a difference. If anything, the foam would tend to decouple it from the floor. I wouldn't think that being situated close to a wall and bookcase would cause a bass roll off. I would have expected this to cause a potential peak and/valley.

I assume you disabled the sub's crossover or turned the high pass filter to the highest frequency.

Try moving the sub around to and use quick measure to see if things improve. If it does, you know the problem is room placement. If things don't change, this will tell you to look for other solutions.

The crossover is disabled.

My Quick Measure charts are posted her for 5 positions: http://www.avsforum.com/t/1289533/anthem-mrx-receivers-300-500-700-owners-thread-tweaking-guide/13740#post_23001200

Not looking easy.. and thanks for your input.

Can you leave it in the front left corner or by the bookcase. Those seem to be the two spots where it doesn't roll off until about 25Hz.. You probably just have a bass null at the other spots.

Can the room be closed off? If the space is very open, it may just be that the sub can't generate enough output give the size and number of openings in the room.

It boosts the bass. I generally just listen in Stereo. but occasionally use DPL2 Music.

The room is only about 3.4m x 3.6m (10x12ft in old money?) and I keep the door closed.

The only "leakage" I can think of is the fireplace although it's bunged when it's not being used (a bag of scrunched up newspaper).

Actually you may be able to make the nulls go away by opening the door.

Thanks, I'll try that, although one of the rear bipole speakers is on the back of the door so I'll have to move it to above the door frame.

But I'll do a Quick Measure first for the sub with the door open before moving the rear speaker.

Don't you just love home cinema

Yeah it is always a challenge. A friend of mine had a pretty steep null in his main listening position with the door closed due to the bass cancelling out. Open the door and it went away.

Completely by coincidence I found "an open door is like a bass trap" on google

http://forums.musicplayer.com/ubbthreads.php/topics/2471794/Help_me_treat_my_first_room#Post2471794


Which bit of my curve is a null? I have a sound level meter, can I use that independently of ARC, or with REW, to help sort out my sub?

You can use REW and an SPL meter but I'm still not sure it's a null. Can you do a quick measure with the door open and post it?

Yes, but it'll be tomorrow as it's after midnight here and I don't think my neighbours will appreciate the test tone

Are you in England? I ask because you are 5 hours ahead of me and you said Home Cinema and not Home Theater like us Americans.

I think mhuk is in England like me. Some of us say 'home theatre' though.

A question regarding the Audio formats being sent between my Oppo bdp103 and my MRX500.

Whether I select DTS, DD 5.1, DD TrueHD 7.1, or DTS HD Master 7.1 the display of the MRX will only display Dolby D 3/2 or DTS 3/2. The rear speakers do NOT engage. This is if the OPPO is set to Bitstream.

Pressing info on the Oppo indicates that the correct format is being output but the MRX input format will not recognize the same format is being input.

If the Oppo is set to LPCM then the rears engage and provide the full 7.1 output. My understanding is either component can decode the lossless formats and the MRX should display the applicable format on screen when receiving a bitstream code.

I have reviewed all settings and cannot seem to figure what could be causing this.

Audio is sent via HDMI, FW version is 50.25, DSP 1 version is 40.01

Audio input and output on MRX Is DD or DTS and I have tried to different HDMI cables to eliminate the cable as the source of the problem. Oppo FW is 38-1220.

Ideas?

Are your listening/mode preset set as follows:

5.1 Dolby Digital: PLIIx Movie
5.1 DTS: Last Used.
DTS-ES: Same as DTS 5.1

After setting the presets up like this play something with DD 5.1. Then put in a DTS 5.1 and it will use PLIIx Movie since that was the "Last Used" format and DTS-ES will use the same as DTS 5.1's last used. Also remember the display shows the incoming signal so for 5.1 it will read 3/2 and if you hit the audio button you'll see PLIIx Movie and you should be able to hear the side a rear surrounds. for 7.1 the display should just reat 3/4 since the incoming signal is 7 channels.

It's only the 7.1 inputs that I really want to work. I can get the rears to engage if I select the PLIIx on 5.1 sources but I never get 7.1 sources to display 3/4. Only 3/2.

DTS 5.1 and DTS HD 7.1 only give me DTS 3/2.... Similar problem with DD 5.1 and DDHD 7.1.

I don't understand it

Here are some examples.

Tinker Tailor Soldier Spy

Select and confirm output from Oppo is DTS-HD MA 5.1

MRX input Displays DTS 3/2, output 5.1 + Neo:6

Prometheus

Select and confirm Oppo is DTS-HD MA 7.1

MRX input displays DTS 3/2, output 5.1 + Neo:6

Same problem with Tron in DTS-HD MA 7.1 and Monsters Inc in 7.1 Dolby TrueHD

@Legairre - guilty as charged

 

Go into the Oppo menu and go to the  audio format menu. Make sure secondary audio is set to off. When this was on I had the same problem as you.

Bingo, that did the trick.

Thanks very much bill1908

Your Welcome!!! It was driving me crazy until I finally figured it out.

Warning: Spoiler! (Click to show)
I know the feeling!

Cheers

Here are my Quick Measures looking at how open/ closed/ sligtly open door affects my sub.

Sadly ARC doesn't seem to do real time: if I opened the door during a Quick Measure it made no difference to the graph. I had to click stop and then start again for ARC to notice anything

Door open:


Door closed:


Door slightly open:


How does an open door make such a difference (50-100hz seems slightly smoother) and more importantly, which is better?

Thanks

The bass waves are bouncing around the room with the door closed cancelling each other out at certain locations. With the door open the can get out.

That makes sense. Now to work out why it seems to go wrong around 150hz- would bass traps help?



Of all the things associated with playing movies and music room acoustics and treatments has to be the most complicated. I've found some great sites (this one looks promising http://www.mh-audio.nl) and lots of DIY options but where to start?

A simple "if you can only do 3 things these 3 will give the most benefit" list of what and why would be very useful. I've got a science degree so I just have to remember how to use my brain and get a grip on the basics

Perhaps this has already been suggested so far, but as far as that quick rolloff that ends at just above 150 Hz, I suspect it's caused by a low-pass crossover in the sub. It's a pretty steep rolloff with no bounces along the way. I would check to be sure that all crossovers on the sub are disabled or, if not defeatable, set to their highest setting.

To be very brief and stay on topic, IMO the two most important acoustical issues to deal with in small rooms are excessive ringing and reverberation in bass frequencies, and treatment of first reflection points. The former requires thick (several inches) broadband absorption panels in wall-wall, wall-ceiling and/or wall-floor corners, and also potentially on parts of the back wall. The latter can be handled with 2" thick absorbers properly placed on sidewalls, ceiling and possibly floor if not carpeted.

I would take a look at www.realtraps.com and www.gikacoustics.com for additional details and education if you're interested. Both are companies that sell acoustical products and offer free advice on your room in particular.