IMAX Solar MAX DTS: A New Subwoofer Killer!

[tk2001]

There are some dvd's that are available which has the potential of literately damaging the driver of a subwoofer because of the very strong output around 20hz, especially if played near reference level. Such tittles include The Haunting DTS, Titan AE DTS, Finding Nemo, U-571 DTS, Jurrasic Park III DTS etc.

Well there is now a hidden gem of a dvd which I have recently purchased called 'Solar Max' which was recommended by some of the bass enthusiaust on the AVS forums for having some of the toughest LFE on dvd today and having trying it out for myself, it really does seem to have very strong SPL around 20hz and my subwoofer was pumping out a massive 122dB at only -05dB reaching well over true Dolby reference level and that is taking the inaccuracies of radioshack SPL meter into account level

Solar Max is a documetary about our Sun and how every 11 years the sun's poles reverse with unimaginable violence and the peak of the storm is called a solarmax. It probably has the best close-up footage of our Sun thus far and is definitely interesting to watch.

The cheapest place I managed to get this for was for just inder £5 including P&P http://www.ezydvd.com.au/item.zml/221378

WHEN WATCHING THIS DVD, PLEASE PAY CLOSE ATTENTION TO YOUR VOLUME LEVEL. PLAYING THIS DVD AT REFERENCE LEVEL HAS THE POTENTIAL OF DAMAGING YOUR SUB!

 

[Andywilliams]

Hi TK
What sub are you using now?
Did you go for the DD velodyne.
Cheers Gonzo.

 

[tk2001]

Originally posted by gonzo
Hi TK
What sub are you using now?
Did you go for the DD velodyne.
Cheers Gonzo.

gonzo,

No, I have not purchased a velodyne DD as their range is way off my budgit. As regards to what sub I am using now, well its a secret.

 

[Ian J]

Originally posted by tk2001
As regards to what sub I am using now, well its a secret.

It isn't you know and I am hoping that you will post your review shortly, exactly as you did with the HGS-18 that preceded it

 

[tk2001]

Originally posted by Ian J
It isn't you know and I am hoping that you will post your review shortly, exactly as you did with the HGS-18 that preceded it

What subs to you know of that can reach a clean 122dB at -05dB (thats around 130dB if you add the correct values to the Radio Shack SPL meter) with the subwoofer calibrate to 85dB exactly using Avia?

I did not play that movie at reference level in fear of my neighborhood.

However, if I was to play that movie at reference level, then I'm quite confident that I'd be hitting 127dB but somehow the thought of 127dB of bass pounding in into me is just too frightening lol.

 

[MuFu]

It's not a Bose Acoustimass bass unit is it?

MuFu.

 

[lilux]

Originally posted by MuFu
It's not a Bose Acoustimass bass unit is it?

MuFu.

LOOOL

 

[morg]

Another Imax dvd to try is the eruption of mount st helens which
also has the potential to damage subs.

 

[Ian J]

I wish that you'd mentioned that earlier as I have just ordered the other one.

 

[morg]

I suppose either one will have the potential for structural damage
with the right subwoofer

 

[stegalv]

can someone please explain in everyday sat in your living room watching a film english what the hell tk2001 means in his thread,
i have been looking at this forum for a few weeks and have just ordered parts to build a sub,so i am trying to understand the subject i understand the words but they don't relate to anything i understand e.g i am an electrician to eplain current flow and capacitors,diodes,resistors its easier to understand if you relate it to water flowing round a pipeing system can someone explain tk2001 subject in this way ,sorry if this is stupid but i don't want to blow my sub up,

 

[fred123go]

btw is dts bass better than dd bass?i am not too knowledgeable about the differences...but seeing as tk mentioned only dts versions i suppose they are better..?
fred

 

[tk2001]

panny300 lol,

What I'm basically trying to say is that is this:

Most dvd movie soundtracks today do not contain subsonic bass frequencies, therefore alot of the commercial subs at around £100 to £300 are able to handle these movies without a problem.

However, there are now more and more dvd movies that are released today containing subsonic material and by that I mean very strong frequencies at around 20hz and below and those frequencies are very hard for a subwoofer to reproduce, especially at very high volume levels.

I'll give you an example of how a dvd movie containing strong frequencies around 20hz managed to permantlyt damage a subwoofer that I owned.

I use to own the Mission FS2 package which I thought was a good 5.1 package at the time. Watching dvd movies through this package was very cinematic. However, after reading in the forums that the dvd movie 'The Haunting' DTS containing some of the most brutal bass on dvd, I ordered it to see what all the fuss was about.

Up until then, my Mission FS2 sub had no problem playing most of the dvd movies that were available at reasonably high volume levels so I put on The Haunting at the volume level I normally listen to and when it arrived to the chapter where there was strong frequencies at around 20hz, well my mission sub just popped.

The driver-cone was moving in and out so ruthlessly (well beyond it's excursion limits) trying to hit those low frequencies that it was popping constantly and that is when I knew that I had to get a more powerful sub. Suffice to say, the Mission sub from that day on was not able to perform as well as it was use to, making popping noises now and again.

 

[tk2001]

Originally posted by fred123go
btw is dts bass better than dd bass?i am not too knowledgeable about the differences...but seeing as tk mentioned only dts versions i suppose they are better..?
fred

fred123go, lets just say that I would personally choose a DTS soundtrack over a DD given the choice and that is my preference.

As to whether DTS is actually better than Dolby Digital, well thats an on-going debate which I am definitely not going to get into lol.

 

[Operandi]

I understand that DTS soundtracks are mixed with a 6db bass boost in the LFE channel, when compared to a Dolby digital soundtrack, hence the bigger perceived bass from DTS soundtracks.

 

[stegalv]

thanks tk i understood that bit can you do the same with the db numbers everybody keeps quoting what is reference level,and 122db at -05db i understand something outputting at 122db but not the -db bits

 

[Smurfin]

Originally posted by Operandi
I understand that DTS soundtracks are mixed with a 6db bass boost in the LFE channel, when compared to a Dolby digital soundtrack, hence the bigger perceived bass from DTS soundtracks.

That's not true; some DTS tracks may be mixed with an LFE boost (and certainly many of the early DTS discs were) but there are many which aren't.

 

[tk2001]

Originally posted by panny300
thanks tk i understood that bit can you do the same with the db numbers everybody keeps quoting what is reference level,and 122db at -05db i understand something outputting at 122db but not the -db bits

Here is an explanation on Reference Level and calibration:

People who own a home cinema system and takes it seriously, normally calibrate their speaker/sub volume levels using a Sound Pressure Level meter (SPL meter) with either the following calibration discs: Video Essentials (VE), Avia or Sound & Vision (S&V) so that from the listening possition, each speaker and sub is outputting the same decibel reading. This creates a perfect ballance between all speakers from the listening possition and I'd imagine this is similar to how your local cinema is set-up.

If you have VE, the test tones are recorded at a lower level than Avia or S&V, so you need to use 75 dB, not 85 dB.

Set your Master Volume to 0.0 and set the meter at the listening position (facing forward at a 45 degree angle) on C-weighted slow on the 70 dB scale.

Play the VE test tones and adjust the speaker levels until you hit exactly 75 dB on the meter for each channel.

For the sub, set the channel level to around -5 (on a scale of -10 to +10) and adjust the sub plate amp until you hit about 76 dB on the meter. It helps to use the 80 scale for less needle bouncing. 76 dB is actually about 78 dB (or 3 dB "hot") due to the c-weighting of the RS meter.

Once the system is balanced and calibrated with VE @ 75 dB (or Avia / S&V at 85 dB), setting the Master Volume to 0.0 when playing a Dolby Digital movie DVD is considered playing back at Dolby Reference Level.

This should result in SPL peaks (at the seat) of 105 dB from surround channels and 115 dB from the LFE channel. If peaks occur in a few channels simultaneously, the combined SPL peaks can approach 120 dB.

The only variable (other than how hot you run your sub) in the equation is the actual mastering level on DVDs - some are mastered hotter than others.

Regardless, once you are calibrated to RL (Reference Level), then you can tell us at what volume you actually like to play back DVDs. Most of us will play them at anywhere from -20 to -10 (with RL being 0.0). A couple of real die-hards push it even harder.

If for some reason your Master Volume scale does not go from the negative range up to 0.0 and then into the positive range, then you need to simply use a different set of master volume numbers and remember which setting you used for RL.

 

[Steve.EX]

I would add that most THX certified kit (certainly the Tag 192/32DP and 32SP) when calibrating kit has no adjustable test tone. When selected it is constant in gain regardless of where the volume control is at. You simply raise or lower each channel to 75db.

Steven

 

[tk2001]

Originally posted by Steve.EX
I would add that most THX certified kit (certainly the Tag 192/32DP and 32SP) when calibrating kit has no adjustable test tone. When selected it is constant in gain regardless of where the volume control is at. You simply raise or lower each channel to 75db.

Steven

Steve.EX,

But is this as accurate as using a dedicated calibration disc such as Avia - most internal test tones from THX-certified processors (Meridian 568.2, Lexicon MC-1 Denon A1SE etc) have always been 2-3 dB off from the test-tones on Avia?

 

[Smurfin]

My MC-1 was 3db off from Avia...

 

[rags]

Does it really matter ? I would imagine that even +or- 5db doesnt really matter as long as all the channels are set to the same level.

 

[stegalv]

bl***y hell tk are you a physics teacher or something,but thanks you are getting me there, don't desert me yet,i have a rad shak spl and ve disk might be able to use them in a bit,watched ve a couple of times but how do i get a constant freq, is there some way of outputting a single freq for as long as needed they all seem to go up the scale for a fixed time on each speaker,when you say master volume to 0 do you mean in the speaker configeration setup in the amp menu or the actual amp volume dial,when it is set up how many decibels is reference,really appreciate the help

 

[iaria]

Listening at reference level according to- tk2001- sounds(pardon the pun) a bit too much.
I usually listen to dvds at about -30, and that is loud enough, but if you ask my wife is too loud.....
Surely listening at 0.0 the sound would be distorted.
Is that the case?? Or I am a bit confused??
Gerry

 

[tk2001]

Originally posted by rags
Does it really matter ? I would imagine that even +or- 5db doesnt really matter as long as all the channels are set to the same level.

rags, you are of course correct. As long as all the speakers and sub are calibrated to the same level then that should be the main goal.

However, as point of reference, if everyone calibrated their speakers/sub to 85dB using a reference disc such as Avia or 75dB for Video Essentials, then one can compare settings or volume levels with other forum members who have calibrated using the same discs.

Also, when someone has a problem with their set-up and they state that they listen to their movies at around -10dB below reference level, then at least people will have an idea of how loud that is in comparison to their own set-up and when someone states that they listen at reference level, we all know that it is BLOODY LOUD.