Dynamic Headroom question...

cokewithvanilla · June 2009

Ok, I have been trying to better understand this concept. It seems simple enough, this is the amount the amp can go above it's normal specs for a short period of time to create those big booms.

This has been the most frustrating thing for me so far, I never feel like I am getting a big enough boom. Either my speakers don't boom, my amp doesn't have enough "dynamic headroom" or I am expecting a bigger boom than was intended.

First of all, what is a good level of dynamic headroom? My amp is the B&K 7270 SII, it has 1.2dB of headroom - which is almost 1db lower than my adcom GFA 5800. However, I am only driving two channels on my 7 channel amp... shouldn't this give me a crazy amount of headroom? or is the amp not designed to pull from other channels?

Also, does anyone know of something (dvd, cd) with a really big bang (not subwoofer stuff) that really goes "bang!"? Things like the death star blowing up and stuff never really sat well with me. I mean, my setup sound pretty good in music and I played "Fight CLub" with just my 25's and it sounded amazing (to me) but I don't know if I am getting the proper bang.

cokewithvanilla · June 2009

let me put it real short, the difference between my softest sounds and my loudest sounds doesn't seem right.

Erik Tracy · June 2009

cokewithvanilla wrote: »

Ok, I have been trying to better understand this concept. It seems simple enough, this is the amount the amp can go above it's normal specs for a short period of time to create those big booms.

This has been the most frustrating thing for me so far, I never feel like I am getting a big enough boom. Either my speakers don't boom, my amp doesn't have enough "dynamic headroom" or I am expecting a bigger boom than was intended.

First of all, what is a good level of dynamic headroom? My amp is the B&K 7270 SII, it has 1.2dB of headroom - which is almost 1db lower than my adcom GFA 5800. However, I am only driving two channels on my 7 channel amp... shouldn't this give me a crazy amount of headroom? or is the amp not designed to pull from other channels?

Also, does anyone know of something (dvd, cd) with a really big bang (not subwoofer stuff) that really goes "bang!"? Things like the death star blowing up and stuff never really sat well with me. I mean, my setup sound pretty good in music and I played "Fight CLub" with just my 25's and it sounded amazing (to me) but I don't know if I am getting the proper bang.

To me, dynamic headroom is a relative concept - meaning the 'reserve' an amp has given the current listening volume.

If you only listen at low volumes, then practically every amp has 'headroom'.

You haven't described the rest of your system or your listening habits in regards to how loud you normally listen to movies or music.

Depending on how loud your listening habits are - maybe no amp will have the 'headroom' you are looking for or expecting to have?

In absolute terms, an amp with only 1 or 1.2 db of headroom is not going to be appreciable.

As I understand it, you need at least 3db of headroom for the sound level to be appreciably 'noticable' in auditory terms -which would equate to x2 the power.

So, if your listening habits result in an amp requiring to deliver 10 watts of power to drive your speakers, then a 3db headroom would mean the amp should be capable of delivering x2 the power, or 20watts.

If the 'bang' you are looking for means that the sound delivered is twice 'as loud' as the nominal volume you are listening at, then the amp would require x10 the power.

And if that nominal value is for your amp to be driving at 10 watts then twice as loud means x10 the power or 100 watts.

In order to understand what your system needs are for headroom, you need to establish what your listening habits are for when you need headroom and how much - which in turn depends on how efficient your speakers are, your room acoustics, how loud you like to listen to, and the dynamics of the music selection in question.

I would think that your B&W (rated at 200w/channel??) has more than enough headroom unless you are trying to recreate a Who concert!

George Grand · June 2009

Things that go bang. Real gunshots are available on the Round-Up cd from Telarc, and any number of 1812 Overture versions use real, digitally OR analog recorded cannons. Bang.

What kind of speakers you got chief?

cokewithvanilla · June 2009

I guess I never thought of it that way. I wonder how much power I am using at my normal listening levels. I guess what I really wonder is how can I tell if I am getting the proper dynamics?

I mean, for the most part my system sounds pretty good. There are somethings I would like to improve, but most of my problems I can associate with poor recordings (for example, any elton john song I listen to sounds muffled... almost like when you have a new product with a LCD and it has a screen protector that you don't notice... the thing looks fuzzy and you go "WTF"... then you take it off... and its all good, well, elton still has the screen protector on). However, in movies, there are very few different versions of that movie, so I feel that I have no other choice to trust that what I have is the best version.

I would like to try a movie that is known to have a great explosion and see if my system will reproduce it properly. It's too bad my amplifier doesn't have any kind of meter on it at all to tell me if I am clipping or not.

cokewithvanilla · June 2009

George Grand wrote: »

Things that go bang. Real gunshots are available on the Round-Up cd from Telarc, and any number of 1812 Overture versions use real, digitally OR analog recorded cannons. Bang.

What kind of speakers you got chief?

Ahh there you go! thats my problem. I have a few versions of the 1812 overture... one of those has military cannon... I don't feel that I get the proper bang... but then again, the recording could have them quiet.

LSi25's

Edit: and along with the bang comes my question of loudest and softest sound... I feel like the loudest sounds should be louder... sometimes I find myself turning it up when I know there is a loud sound coming

Many times I wonder if its just that I have gone crazy...

polkie4life · June 2009

Headroom?

Every amp will run out of headroom eventually, depending on what volume you listen at. It's also not a matter of pulling power from other channels, i think it's about not taxing the power supply as much only running 2 ch's. A lot comes down to manufacturer ratings, the ones that don't increase power have usually been rated with all ch's driven.

One scene i really like for for headroom is the bus scene in TDK. The scene is explosive and the volume just climbs up and up.
Musically i cant think of anything in particular, but will say when you have it you will no longer hear any compression.

McLoki · June 2009

Do you notice any difference with DTS tracks vs DD? Could you have some sort of night mode (dynamic range compression) enabled? (usually night mode will not affect a DTS track - thats why I ask)

cokewithvanilla · June 2009

Hmm. I wonder what the preamp is set to on defaults. I know recently I went through and adjusted it to "Loud". I have few, if any, DTS movies at hand right now.

Can you tun off compression? or is "Loud" equal to "off"?

cokewithvanilla · June 2009

____

McLoki · June 2009

loud = off. For example, on my AVR I can set the night mode to 100, 75, 50, 25

I believe

100 is no compression at all
75 is compressed 25%
50 is compressed 50%
25 is compressed 75%.

That is why I ask - it can be kind of confusing....

cokewithvanilla · June 2009

I have loud normal and quiet.... none of them change the sound (when somehting changes in the sound, it pauses the sound a second and turns it back on). However, there is some neo6 setting that has cinema and music, which turns the sound on and off, but doesn't sound different

Tony M · June 2009

You have the the LSI25's with the powered subs built in? Are they pluged in? You should have some serious Boomin and no volume issues for sure. good luck figuring it out, and nice gear!

Tony M · June 2009

I forgot ...U-571 has some serious bangs from the depth charges!!!!!!!!!!

cokewithvanilla · June 2009

Well, I'm not talking about subwoofer booms. I fixed that problem. They boom quite loudly now. I'm talking about gunshots, cannon, and the higher frequency explosions.

To me, it seems like they are not loud enough compared to what else is going on around them. Like, if I talk to someone, then shoot a gun, and resume talking... the dynamics changed greatly between my conversation and my shooting. However, if this happens in a movie, it sounds like if the actor raised his voice just a little he would be able to talk over the gunfire.

heiney9 · June 2009

HT boom comes from a subwoofer. No way the LSi 25's will give you that Home Theater thump without a sub.

Both the amps you are using are NOT the issue. It's either a set-up issue or setting on the processor or it's time for a decent sub. You can't really get by with a serious HT set-up without a sub (if you're looking for big booms). The Dolby processing on the movies count on the user having a subwoofer.

Now for 2 channel music.....................that's a completely different animal.

FWIW

H9

EDIT: just read the above post......you have subs. Perhaps the LSi's are just too "soft" for the type of sound you're lloking for. Perhaps RTiA's are more suitable for the type of HT experience you're looking for.

tcrossma · June 2009

I have LSi15's that I use for combined HT and 2-channel and I have no problems whatsoever with the dynamic range on things like gunshots, cannons, etc. I don't have a sub in my system these days, so it's just the 15's doing the work.

From what you're describing it sounds to me as if your processor might be to blame. Either a configuration setting, or maybe just the way that processor is. Did you say what are you using for a processor/receiver?

I don't think this is an amp / headroom issue you're dealing with. It could also be something of a room treatment issue, with cancellations at certain frequencies.

heiney9 · June 2009

tcrossma wrote: »

IFrom what you're describing it sounds to me as if your processor might be to blame. Either a configuration setting, or maybe just the way that processor is. Did you say what are you using for a processor/receiver?

I don't think this is an amp / headroom issue you're dealing with. It could also be something of a room treatment issue, with cancellations at certain frequencies.

The more I think about it, the more this is likely the culprit.

treitz3 · June 2009

cokewithvanilla wrote: »

Well, I'm not talking about subwoofer booms. I fixed that problem. They boom quite loudly now. I'm talking about gunshots, cannon, and the higher frequency explosions.

To me, it seems like they are not loud enough compared to what else is going on around them.

A lot of this has to do with the recording. The recording engineers will often boost soft whispers, birds chirping during quiet passages or maybe a solo with no music in the background and attenuate a cannon blast or a gunshot so that folks don't blow their systems up. There are other factors as well, but I won't get into those. Unfortunately it happens in music and HT. If you have a revealing enough system, you can actually hear when the engineers do this. They also seem to attenuate all channels of recording when the track gets "busy" with multiple loud sounds/instruments or noises. This may be what you are hearing. Drives me nuckin' futz.

The other part has to do with where your volume setting is at. If your amp and speakers are already maxed out or even close to it, a hard hit or gunshot will go until your equipment is maxed out and at that point, your rig will offer no more.

The 1812 [some versions, not all] does NOT attenuate the cannon blasts which is why they have a warning label on the cover. I have actually witnessed the cloth on a pair of Carver Amazing Plat's move up and down violently to the frequency of the cannon blasts and let me tell you, I thought the damn speakers were gonna blow. They didn't, to my surprise. After I saw that I keep the volume low on my rig until I hear the cannons and adjust the album to the cannons. That way, there are no issues and I can enjoy the album distortion free without fear of damaging anything. BTW, seeing the speaker cloth move like that was definitely a sight to behold. It's something you don't forget.

ESavinon · June 2009

Erik Tracy wrote: »

To me, dynamic headroom is a relative concept - meaning the 'reserve' an amp has given the current listening volume.

If you only listen at low volumes, then practically every amp has 'headroom'.

You haven't described the rest of your system or your listening habits in regards to how loud you normally listen to movies or music.

Depending on how loud your listening habits are - maybe no amp will have the 'headroom' you are looking for or expecting to have?

In absolute terms, an amp with only 1 or 1.2 db of headroom is not going to be appreciable.

As I understand it, you need at least 3db of headroom for the sound level to be appreciably 'noticable' in auditory terms -which would equate to x2 the power.

So, if your listening habits result in an amp requiring to deliver 10 watts of power to drive your speakers, then a 3db headroom would mean the amp should be capable of delivering x2 the power, or 20watts.

If the 'bang' you are looking for means that the sound delivered is twice 'as loud' as the nominal volume you are listening at, then the amp would require x10 the power.

And if that nominal value is for your amp to be driving at 10 watts then twice as loud means x10 the power or 100 watts.

In order to understand what your system needs are for headroom, you need to establish what your listening habits are for when you need headroom and how much - which in turn depends on how efficient your speakers are, your room acoustics, how loud you like to listen to, and the dynamics of the music selection in question.

I would think that your B&W (rated at 200w/channel??) has more than enough headroom unless you are trying to recreate a Who concert!

Sorry but your 3 db headroom number is wrong.

http://en.wikipedia.org/wiki/Decibel

renowilliams · June 2009

ESavinon wrote: »

Sorry but your 3 db headroom number is wrong.

http://en.wikipedia.org/wiki/Decibel

This is a quote from the link you referenced " A change in power ratio by a factor of two is approximately a 3 dB change. (More precisely, the factor is 103/10, or 1.9953, about 0.24% different from exactly 2.) Similarly, an increase of 3 dB implies an increase in voltage by a factor of approximately √2, or about 1.41, an increase of 6 dB corresponds to approximately four times the power and twice the voltage, and so on. (In exact terms the power ratio is 106/10, or about 3.9811, a relative error of about 0.5%.)"

Seems to me that Erik was right.

heiney9 · June 2009

Perhaps this will shed some light

Decibel
We've all used the term "decibel" hundreds of times, but what does it REALLY mean? A decibel (named for Alexander Graham Bell) is a tenth of a bel, and is used as an expression of power. Here's where the confusion arises: A decibel isn't a measure of ANYTHING; it is a ratio of two power levels. Because of the way our ears perceive volume, these ratios follow a logarithmic curve, expressing them as a decibel keeps things easier to deal with. Here are a few convenient decibel figures worth remembering: One decibel is commonly taken as the smallest volume change the human ear can reasonably detect. Doubling the POWER of an amplifier results in a 3 dB increase, which is a "noticeable" volume increase. Doubling the VOLUME of a sound is a 6 dB increase (you may occasionally see 10 dB listed as the "double-volume" figure, 6 dB is the more mathematically correct number). By doing the math, you can see that truly doubling your volume actually requires 4 times the amplifier power! Keep these figures in mind the next time you are comparing the specs of two pieces of equipment...

cokewithvanilla · June 2009

Emotiva DMC-1 is my processor... dunno if this is a problem. But when I plugged my dvd player straight into the amp, it seemed to behave the same.

Which versions of the 1812 overture have speaker-blowing cannon?

hearingimpared · June 2009

cokewithvanilla wrote: »

Emotiva DMC-1 is my processor... dunno if this is a problem. But when I plugged my dvd player straight into the amp, it seemed to behave the same.

Which versions of the 1812 overture have speaker-blowing cannon?

Telarc and several others.

tcrossma · June 2009

cokewithvanilla wrote: »

Emotiva DMC-1 is my processor... dunno if this is a problem. But when I plugged my dvd player straight into the amp, it seemed to behave the same.

Which versions of the 1812 overture have speaker-blowing cannon?

Do you have the issue when watching a movie via cable as well? Just trying to take the DVD player out of the loop here too...

I actually used to have the opposite problem as you, whereby action scenes would be too loud and dynamic. The volume used to hear dialog well would cause bullets, car crashes, etc. to become too loud and I'd have to adjust the volume on a scene-by-scene basis. My solution was some calibration, some speaker placement and room configuration settings, and changing my receiver to "Standard" dynamic range (from *Max*, Std or Min).

It just doesn't seem to me that your issue is the amp or the speaker selection. I assume you've verified that all the drivers and the tweets on the speakers are working?

The way it sounds to me is as if your receiver or DVD player is compressing the dynamic range, either from a setting or just the way that component sounds. Triple check all settings on the receiver and DVD player to make sure that the dynamic range settings are set to Max.

cokewithvanilla · June 2009

I checked the settings on the preamp and everything seems right. I need to find the remote to the dvd player to check that. Unfortunately, I don't have cable since I don't really watch tv.

Edit: yeah, I don't think its the amp either anymore. When I was reminded in the first reply that headroom is only really applying fully if I am fully utilizing the 200wpc, or in my case 385 at 4ohms....

cokewithvanilla · June 2009

I just tried a Telarc version and the whole thing sounded muffled. I could have made a louder boom by puffing my cheeks out and slapping them with my hands.

Hmm, I wonder if anyone here has the software required to make a simple test file with soft noise, then a big bang.

treitz3 · June 2009

cokewithvanilla wrote: »

I just tried a Telarc version and the whole thing sounded muffled.

Ok, then you have a definite issue with something in your rig.

treitz3 · June 2009

Let me ask you this. Have you literally gone up to each driver of the speakers and verified that each driver is in fact working [putting your ear right up against the driver.....maybe an inch or so away]? Try that first and then double check that the speakers are in phase. Then get back to us please.

cokewithvanilla · June 2009

They are all fine. Although the telarc was muffed, if I play at least 60% (probably more like 80-90%) of my other stuff, its just fine. Also, the voices in movies sound excellent.

The only thing I feel that is lacking is that kick (increase in volume) that I should get from really loud sounds.

cnh · June 2009

Interesting, info above...so I guess I've been operating on false numbers, as I'd read/misread somewhere that to double the loudness you needed to 10 X the wattage so that 1000 watts would be twice 100 watts. Which is why you see so many subs above the mid-range at 1000 watts or more? And class D-amps as the choice because of the gross need for power for BASS amping.

cnh

Dynamic Headroom question...

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