|
|
Post by igorzep on Jun 3, 2015 13:23:49 GMT -5
I have one dip all fronts that Dirac applied about 10db correction to them So it could be normalisation to avoid clipping that makes it stop at -4 dB, but it does sound odd. If it is due to normalisation then XMC-1 should know it is reaching it's limit and impose maximum maximum limit and not let the user to change the volume above -4dB if it is the point where regulators are fully open... It is strange that it displays it can, and allows to do it, but noop... Something for Emotiva to consider (if it is the issue). Otherwise, if you reduce level of all channels by let say 10dB (set them all to -10dB if they are all zero now) - then will this extend the 'operating' range to +6dB? If yes, then probably normalization is the issue... Any EQ reduces headroom. And when levels are set to 0dB it is trivial to drive pretty much any commercial amp to clipping already. |
|
|
|
Post by usxplong on Jun 3, 2015 14:06:06 GMT -5
Well, bad news. Emo does not know what is going on with Dirac preset but they are looking into it.
So hopefully they will fix it in next fw.
But it is not the clipping issue with XMC-1 because the presets 1 & 2 are working fine all the way to +11 db.
If it was clipping then the same issue should have happened on presets 1 & 2 as well.
We have to find out if all units have this problem with Dirac preset or just a few units.
If it is all units then Emo should take care of it. And if it is only a few units then we have defective units and should be replaced.
But regardless, Emo's customer service is top notch and I really appreciate it.
|
|
KeithL
Administrator 
Posts: 10,275
|
Post by KeithL on Jun 3, 2015 15:58:29 GMT -5
I talked to engineering, and they confirmed what we already suspected was going on. As you already know, the XMC-1 does indeed apply level normalization to prevent it from clipping the audio signal. The normalization routines also operate to raise the overall gain if you've selected options that lower it.... and, because Dirac tends to reduce the gain, the normalization routines typically raise the gain about 10 dB when the Dirac Preset is enabled. (When you activate the Dirac Preset, it drops the level, and the normalization routines raise it by an equivalent amount so you don't hear an overall drop in level.) It's easiest to think of it this way. If you set the Volume on your XMC-1 to +11 dB, then keep turning the knob to the right, the knob turns but the numbers don't change - because they're already "at the top". However, the numbers in the Volume DISPLAY aren't directly tied to the internal volume control in the XMC-1 (where the actual volume control inside the XMC-1 is set when you set the KNOB to -20 depends on the normalization and gain settings). If the internal normalization routines have already raised the internal gain, your XMC-1 may actually reach it's maximum gain setting internally before the numbers on the display reach +11 dB. If that happens, when you turn the Volume Control up higher, the numbers in the display and the length of the Volume display bar keep going up, but the actual gain doesn't - because it's already "all the way up". This means that your observations are entirely correct - the gain of the XMC-1 isn't increasing when you turn the Volume up past "-4 dB" because it's already "at max" when the Volume CONTROL is set to -4 dB. And the reason that this maximum level is lower in the Dirac Preset than in the other Speaker Presets is because Dirac has reduced the gain over most of the audio frequency range. +11? What db level is that measuring in your room? In mine, my ears would be bleeding! And bmoney...the excerpt of the manual in the post above yours says 1 db increments...fits with what you experience. Mark As I mentioned, the volume level (db) does not go louder from about -4db to +11db in Dirac preset. Which means the db level in -4 is the same as db level in +11. |
|
|
|
Post by millst on Jun 3, 2015 16:15:48 GMT -5
Otherwise, if you reduce level of all channels by let say 10dB (set them all to -10dB if they are all zero now) - then will this extend the 'operating' range to +6dB? If yes, then probably normalization is the issue... Any EQ reduces headroom. And when levels are set to 0dB it is trivial to drive pretty much any commercial amp to clipping already. I disagree. My amps are nothing esoteric and don't clip at 0dB. Somebody purchasing a $2500 pre-pro shouldn't be picking their amp(s) out of a bargain bin. Watts are cheap nowadays. One can easily pick up a new Onkyo PA-MC5501 that is THX Ultra2 certified for less than $1899. People can say what they will about THX, but tests are run to verify the amp meets 105dB peaks with no clipping and minimal distortion in a 3000cf room. An XPA-7, same price range, measures even better I'm sure. -tm |
|
|
|
Post by igorzep on Jun 3, 2015 16:51:40 GMT -5
Otherwise, if you reduce level of all channels by let say 10dB (set them all to -10dB if they are all zero now) - then will this extend the 'operating' range to +6dB? If yes, then probably normalization is the issue... Any EQ reduces headroom. And when levels are set to 0dB it is trivial to drive pretty much any commercial amp to clipping already. I disagree. My amps are nothing esoteric and don't clip at 0dB. Somebody purchasing a $2500 pre-pro shouldn't be picking their amp(s) out of a bargain bin. Watts are cheap nowadays. One can easily pick up a new Onkyo PA-MC5501 that is THX Ultra2 certified for less than $1899. People can say what they will about THX, but tests are run to verify the amp meets 105dB peaks with no clipping and minimal distortion in a 3000cf room. An XPA-7, same price range, measures even better I'm sure. Disagree with what? How do you know they don't clip? Have you measured them with 0dBFS signal (don't try with speakers connected!)? Your amps does not accept decibels and not output decibels. They accept voltage and output voltage (multiplied by current giving Watts). What they have is voltage gain. Most commercial amps have a gain of 29dB (including the Onkyo you have referenced). I have amps with just a 26dB gain (less than average) and they can output clean 400 Watts/channel. Still, they clip once input voltage is more than ~2V RMS (as they reach their power supply voltage on the speaker terminals). XMC-1 at it's max gain have more voltage at its outs for the 0dBFS signal. End of story.  If XMC-1 in Dirac preset does not reach it's max signal amplitude on the outputs - then this is another story... But there are just too many variables not mentioned to make such conclusions. |
|
KeithL
Administrator
Posts: 10,275
|
Post by KeithL on Jun 3, 2015 17:04:18 GMT -5
Exactly.... they can specify that the amplifier delivers a certain number of WATTS before clipping, but what dB SPL that number of watts will deliver out of a speaker depends on the efficiency of the speaker and the size of the room. (Speakers vary in efficiency by up to about 20 dB, and, the bigger the room, the less SPL you'll get for a given power level.) THX certification was a reasonable attempt to establish a standard... but it simply didn't catch on. I disagree. My amps are nothing esoteric and don't clip at 0dB. Somebody purchasing a $2500 pre-pro shouldn't be picking their amp(s) out of a bargain bin. Watts are cheap nowadays. One can easily pick up a new Onkyo PA-MC5501 that is THX Ultra2 certified for less than $1899. People can say what they will about THX, but tests are run to verify the amp meets 105dB peaks with no clipping and minimal distortion in a 3000cf room. An XPA-7, same price range, measures even better I'm sure. Disagree with what? How do you know they don't clip? Have you measured them with 0dBFS signal (don't try with speakers connected!)? Your amps does not accept decibels and not output decibels. They accept voltage and output voltage (multiplied by current giving Watts). What they have is voltage gain. Most commercial amps have a gain of 29dB (including the Onkyo you have referenced). I have amps with just a 26dB gain (less than average) and they can output clean 400 Watts/channel. Still, they clip once input voltage is more than ~2V RMS (as they reach their power supply voltage on the speaker terminals). XMC-1 at it's max gain have more voltage at its outs for the 0dBFS signal. End of story. If XMC-1 in Dirac preset does not reach it's max signal amplitude on the outputs - then this is another story... But there are just too many variables not mentioned to make such conclusions. |
|
|
|
Post by millst on Jun 3, 2015 17:24:47 GMT -5
I disagree that any commercial amp is necessarily clipping with the volume at 0. Maybe I just don't understand what you were saying.
My amps have level/clip meters. According to those, they are are nowhere near clipping. The scope would a better way to tell, but I don't own one.
I understand how amps work. 400 clean watts should hit reference levels, assuming somewhat efficient speakers and reasonable listening.
-tm
|
|
|
|
Post by autocrat on Jun 3, 2015 17:42:34 GMT -5
Maybe a little PEAK indicator on the OLED would clear things up.
|
|
|
|
Post by geebo on Jun 3, 2015 19:12:44 GMT -5
I disagree that any commercial amp is necessarily clipping with the volume at 0. Maybe I just don't understand what you were saying. My amps have level/clip meters. According to those, they are are nowhere near clipping. The scope would a better way to tell, but I don't own one. I understand how amps work. 400 clean watts should hit reference levels, assuming somewhat efficient speakers and reasonable listening. -tm I think they're talking about keeping the XMC from clipping. Not your amp. But if your amp receives a clipped signal what do you think the result would be? |
|
|
|
Post by millst on Jun 3, 2015 19:29:22 GMT -5
Ah, just saw Keith's posts. You'll get an amplified version of your clipped signal. Garbage in, garbage out.
The behavior is different from other processors I've used. Typically, the volume has stuck at whatever level the unit considers max for its current settings. The absolute max value might be +10, but sometimes you would get stuck at +4 (or +0 with different settings) no matter how much you turned the dial.
Avoiding clipping is good, but doesn't the routine seem overly aggressive? The regular presets get much louder. Either those are clipping or the Dirac is far from it.
-tm
|
|
|
|
Post by Gary Cook on Jun 3, 2015 19:41:58 GMT -5
My simple view is that DIRAC balances the channel outputs, that's volumes across frequencies. Hence some channels get more watts, some channels get less watts and at the same time some frequencies get more watts, some frequencies get less watts. So the master volume displayed is really an average of all the channels and frequency volumes. Simplistically just because the master volume says "0" it doesn't mean that one channel/frequency isn't playing at say +5. For me I'd like the "clipping prevention protocol" to work based on that channel/frequency, ie; if one is clipping then the average volume has to be controlled even if the all the other channels/frequencies aren't.
Cheers
Gary
|
|
|
|
Post by albertiwell on Dec 16, 2015 11:19:49 GMT -5
The point is that I am suffering the same problem but with the preset-1, which supports a REW calibration I did.
No volume increases from 0 dB to +11 dB.
I thought it was a problem with my JBL LSR 308 `s (auto-amplified), but not.
Its me the only one to suffer that problem even in a non-DIRAC preset?
|
|
|
|
Post by socketman on Dec 16, 2015 15:30:34 GMT -5
The point is that I am suffering the same problem but with the preset-1, which supports a REW calibration I did. No volume increases from 0 dB to +11 dB. I thought it was a problem with my JBL LSR 308 `s (auto-amplified), but not. Its me the only one to suffer that problem even in a non-DIRAC preset? I have never tried this since I don't listen that loud, so I wonder what happens when you use preset 2. Perhaps the filters you created are driving the signal past its safe limits and its limiting it to prevent too high output voltage or a clipped output voltage. |
|
|
|
Post by albertiwell on Dec 17, 2015 6:58:02 GMT -5
The point is that I am suffering the same problem but with the preset-1, which supports a REW calibration I did. No volume increases from 0 dB to +11 dB. I thought it was a problem with my JBL LSR 308 `s (auto-amplified), but not. Its me the only one to suffer that problem even in a non-DIRAC preset? I have never tried this since I don't listen that loud, so I wonder what happens when you use preset 2. Perhaps the filters you created are driving the signal past its safe limits and its limiting it to prevent too high output voltage or a clipped output voltage. Thanks for your reply. The filters i created for both L/R channels are in the negative spl side, and a couple of +5 dB each. My "near field " studio monitors are awesome flat response, incredible off-axis response, but not powerful, so I need to use the XMC-1 on the near -5dB to +5dB area often. I deppend on the level of the recordings. If they are high enough, no problem at my 3,5m listening position, but if they are a little low level recorded, then i miss that the XMC-1 will use this +11dB that is supposed to manage. |
|
|
|
Post by socketman on Dec 17, 2015 11:07:28 GMT -5
Back when I first got my XMC-1 I had to set my levels using the internal testone after running Dirac because Dirac set the levels too low. This was corrected with firmware but I still use my SPL meter with the internal tones to double check all my levels. I would suggest you do the same and see what you get, boosting the levels will raise the preamp output.
|
|
|
|
Post by total2727 on Dec 18, 2015 0:16:09 GMT -5
At -20 in my room with XMC/ XPA-5 I will break things!!
|
|
|
|
Post by usxplong on Jan 20, 2016 14:18:00 GMT -5
OK, I think I found the issue or should say the solution for volume problem or normalization on XMC-1.
XMC-1 adjusts the volume ONLY based on the subwoofer volume, not any other frequencies.
XMC-1 does not care about other frequencies so it is not the whole range distortion adjustment by XMC-1 as was reported here by EMO ar at least that's what I understood.
If you have a dip in the lower part of your curve and DIRAC boosts it up then XMC-1 will control the volume to not send too much to your subwoofer.
The solution that I am going to try is to lower the sub level in the DIRAC preset and raise the sub level on subwoofer to the desired level.
By that I think we will fool XMC-1 and get a higher volume level.
So based on how many db you lower the sub level in DIRAC preset, you can go that many db higher on the volume knob.
|
|
