Again Keith all I said was there are different ways to get to reference. You are obviously sticking up for your buddy here which I can understand but no need to keep putting words in my mouth that I never said.
Is this an attempt at irony?
Is this an attempt at irony?
This is a different topic so I will comment. That is just 'audiophile' nonsense I'm afraid, so in fact far from being 'no doubt' there is considerable doubt. The amount of power 'put into' a speaker is entirely related to the sound output required from the speaker. So if the speaker needs xx watts to generate yy SPL without clipping then that is it. End of. So long as the amp can cleanly generate xx watts, then it is all that is required. Having a far more powerful amp and 'leaving the additional watts on the table', ie unused, serves no purpose at all. None. As in zero.
If you pumped 400 watts into the PSB Golds then, for that amount of power, they would have generated a known and quantifiable SPL. Are you saying that those speakers were no use unless you played them at that SPL? I don't think so. If you mean you believed you needed a 400 watt amp to make them 'wake up' even though you were only using, say, 100 watts of the available power, surely you can see that the unused power cannot possibly have any bearing whatsoever on the sound produced by the speakers?
No - nothing here was ruffled, so no need to apologise :)
Hi - when you say you used your SPL meter to check, do you mean that after calibration you played the AVR test tones and then measured the level of the tones from the MLP? If so then yes, you should read 75dB for all channels, as this was the calibrated level. The test tones, however, bypass Audyssey so if Audyssey had to make considerable FR adjustments, it is possible that the levels when bypassing Audyssey are different to those achieved when Audyssey is engaged. But if you also used an external source of tones, then these would take account of the audyssey calibration anyway. I have found that my meters aren't very accurate in the bass region so I generally ignore any readings for the subs. All our experience shows that Audyssey is pretty good at calibrating levels, so I would always tend to believe Audyssey rather than my meters, even though I have excellent software meters and a fairly expensive, calibrated mic.
Nothing probably. Reference doesn't mean all movies will sound as loud as all others. It just means that the average level through the movie is 85dB and peaks should not exceed 105dB or 115dB for the LFE channel. A quiet movie such as a dialogue-driven drama will not sound as loud as a full-on action movie. And even some action movies will sometimes sound louder than others - for example The Dark Knight is an incredibly loud movie - I am not sure if this is because the average of 85dB is achieved more or less all the time during the movie (85dB is actually pretty loud) or if the movie has actually been mixed at higher than Reference levels (which would surprise me).
I also believe that Dolby's Dialog Normalization feature has a bearing on this but my understanding if Dialnorm is sketchy and changes every time I read about it, so ICBW on that.
I typically aim to listen on my system at -6dB but I find that with some movies I need -3dB and with others -9dB. I don't worry about it much - I tend to set each movie to a level where dialogue sounds natural and then leave it there for the entire movie.
Do you use Dynamic EQ? If so, that will also impact on perceived loudness, especially of the bass. I assume you are not using stuff like Dynamic Volume as this compresses the range of sounds (softest to loudest) and gives the impression of sounds sounding more similar to each other whether loud or soft (IOW it compresses the dynamic range of the material).
Perhaps others will chime in with their views?
On the back of your sub there is a knob called 'gain' or 'volume' or similar. Turning the knob in a specific direction (usually clockwise) will make the sub louder. That is what they mean when they say to turn the sub volume up. It's a pre-check to set the sub to the right level so that when Audyssey runs it calibrates the sub trim to be somewhere in the middle of its range rather than at the extremes.
If your sub gain control is marked -30 to 0, then 0 is the loudest. If you currently have it set to, say, -15 and it is asking you to turn the volume up, you need to to -10 or whatever - towards 0 anyway.
If 0 is the loudest the sub can play, then -30 is, for example, 30dB below 0. So -10 is only 10dB below 0, hence louder. Have I explained this clearly?
Mine are passive. IDK how much power they use to reach Reference, but they are powered with (rated) 300 watts each channel (likely more on peaks I’d guess). The Crown calculator shows that is enough at my seating distance:
When I set the MV to 0dB and take a reading with my SPL meter, I see peaks of 105dB (and sometimes more - probably due to inaccuracies in the meter?).
AIUI, THX specs require that Reference is attainable at the listening distance specified for the THX rating (Ultra 2, Select 2 etc). This is what it says on the THX website:
THX Ultra2THX Ultra2
THX Ultra2 Certified products bring the cinematic experience to larger home theaters, 3,000 cubic feet in size, with a viewing distance of 12 feet or greater from the screen.
THX Select2THX Select2
THX Select2 Certified products are for medium sized rooms, up to 2,000 cubic feet in size, with a 10-12 foot viewing distance from the screen.
It doesn't specifically state there that they are meaning Reference levels, but it is clear from other information on the site that this is what they do mean.
In general, I think all that matters is that a system can meet the SPL requirements of the user of that system, cleanly, without clipping and without endangering the equipment itself. If a system can do that, then no more is required of it. I typically listen at about -5dB and the Crown calculator shows that I need 68 watts for that (chickenfeed).
Even with 3dB headroom I'd only need 136 watts, which is easily attainable here.
EDIT: In my original post, quoted above, I mistakenly gave the sensitivity of my speakers as 89dB - on checking it turns out to be 90dB.
It all looks OK. If Audyssey has to re-chirp it means that ambient noise is higher than expected, or more accurately the SNR required for calibration is not being met, which in turn could mean the sub is simply too quiet. There is no harm in turning up the gain on the sub itself a little next time you run Audyssey. This will probably negate the need for Audyssey to re-chirp and it will result in a trim setting of maybe -5 or -7 or whatever (depending on how far you turn up the sub gain). But there is nothing wrong at all with a sub trim of -3.
Incidentally, I am suspicious of why Audyssey needed to re-chirp the sub this time if it hasn't had to in the past. Are you sure that you haven't moved the sub into a null in the room?
As my speakers have to meet a certain spec in order to gain their THX certification, I would assume that their spec tolerances are extremely tight.
I prefer the Crown SPL calculator these days as it is more conservative than some of the others, so it gives a 'safety margin'. The only real way to test the SPL of course is in the actual room.