• New Patreon Tier and Early Access Content available. If you would like to support AVForums, we now have a new Patreon Tier which gives you access to selected news, reviews and articles before they are available to the public. Read more.

Sub problem

newcomers

Active Member
hi guys, happy new year

I had a new install in the summer (50in Plasma Samsung, sky +, another sat and a jamo 5.1 surround sound system)

Ive recently added a ps3 to the setup but i have an annoying problem.

The other night we were watching superman on blu-ray. When it was just dialog we could barely hear it, but with an action scene we had to turn the volume right down as it was too loud, only to have to turn it up even more for the dialog scenes. Im not sure if this is caused by too much base, but on normal tv it seems fine. How do I level out the audio levels a bit more? btw the ps3 is connected via digital optical

Also, on the sub there are 3 knobs. Level, cut off and phase.

Level is obviously the volume but what are the other 2 and what shouold they be set to?

Thanks a lot
 

newcomers

Active Member
also, is there some sort of cd / dvd i can buy to set / balance my system?

Thanks
 

gblades

Active Member
I am guessing it is related to the audio track on the blueray disc. DTS tracks for example tend to have a large dymanic range which will cause explosions to be loud when you have the volume turned up to hear the vocals. If you are watching it and dont want to annoy the neighbours try switching to a different audio source or use the 'dynamic range compression' feature on your amp if it has it.
 

gblades

Active Member
cut off is probably the frequency cut off. Amps would normally handle this themselves but I suppose if you are driving the sub from a normal signal then you could adjust the cutoff frequency to match the frequency response of your speakers so that you got a flat overall frequency response. If everything is going via the amp then there is no need to adjust it.

phase would adjust the phase of the sub. If you have two or more devices producing very low bass then the phase will need to be tweaked so that both bass signals combine properly. Its easily done by just listening to a bass tone and tuning it until you get maximum volume. If you only have one bass it makes no difference.
 

newcomers

Active Member
yeah was thinking that but then i dont want to lose the bass completely, and all the effcts that go with it
 

gblades

Active Member
I dont know what type of audio tracks you typically get on blueray but for example dolby digital 5.1 typically has a lower dynamic range than DTS. So if you both audio tracks available switching to DD would help.
 

newcomers

Active Member
whats dynamic range?
 

newcomers

Active Member
cut off is probably the frequency cut off. Amps would normally handle this themselves but I suppose if you are driving the sub from a normal signal then you could adjust the cutoff frequency to match the frequency response of your speakers so that you got a flat overall frequency response. If everything is going via the amp then there is no need to adjust it.

phase would adjust the phase of the sub. If you have two or more devices producing very low bass then the phase will need to be tweaked so that both bass signals combine properly. Its easily done by just listening to a bass tone and tuning it until you get maximum volume. If you only have one bass it makes no difference.

im confused lol

I have a sub, but the speakers arent wired through the sub. The sub has 2 wires from the reciever and the mains is in the plug.

Basically I have level half way and not sure what to do with the other 2

I dont know what you mean by "if i only have 1 bass"
 

newcomers

Active Member
Jamo A102HCS11.Black

DMR61 DVD Receiver plus 5.1 Speaker Package
 

gblades

Active Member
whats dynamic range?
Basically is the difference in volume between the quietest sound and the loudest sound.

So if you switch to a audio source with a large dynamic range from a standard stereo source you will tend to find that vocal (and most of the audio) is quieter but explosions are the same (max volume). Thats why a lot of people say film channels and dvds are quieter than normal tv.
 

newcomers

Active Member
so is what ive described normal then?

I find it really annoying, i find myself adjutsing the volume loads during films
 

gblades

Active Member
im confused lol

I have a sub, but the speakers arent wired through the sub. The sub has 2 wires from the reciever and the mains is in the plug.

Basically I have level half way and not sure what to do with the other 2

I dont know what you mean by "if i only have 1 bass"

In that case leave the cut off in the standard position (either center position if it is marked or just set it to maximum). The amp controls what frequency ranges are sent to each speaker so the setting does not matter for your wiring.

When considering sub frequencies think of it as pushing air around. If you have one sub close to you and one much furthur away when there is a sudden amount of bass they will buth start pusing and pulling air at the same time.
Now these bass notes take time to travel through air if a high pressure reaches you from one while a low pressure reaches you from the other they will cancel each other out. In reality there will only be a sight difference in timing and this is where the phase adjustment comes in. If you delay the signal from the sub which is closest to you so that its sound reaches you at the same time as the one furthest away the bass effect will be maximised.
Normally people dont have two subs but some people have floor shakers which go in the floor or under the chairs and give you bass that you can feel but the same principles apply.
 

gblades

Active Member
so is what ive described normal then?

I find it really annoying, i find myself adjutsing the volume loads during films

Yes it is normal but the amp should have a setting to reduce the dynamic range. My Yamaha RXV595RDS which probably is about 10 years old even has this setting and it only supports DD and not DTS.
 

gblades

Active Member
If you want to have a play with the phase interferance I mentioned earlier try this :-

Play some basey music and make sure the amp is not set to prologic mode so that audio is only coming from the front two speakers. Then unplug the wires from one of the speakers and swap the polarity. The signal will now be out of phase and the bass should sound a lot quieter.
It all depends whether or not the front speakers are capable of producing much bass though.
 

newcomers

Active Member
I think my sub only supports if it playing a dvd through the act throuual receiver, but not through any inputs

so going back to the sub settings, level ill play with, cut off ill check out and phase?
 

newcomers

Active Member
just looked at the bluray disc i mention and its DD and not DTS
 

newcomers

Active Member
also found a setting on the amp called "dynamic range"....


its currently off but the settings go:

2/8
4/8
6/8
full

what do they each do?

Thanks
 

gblades

Active Member
I think my sub only supports if it playing a dvd through the act throuual receiver, but not through any inputs

so going back to the sub settings, level ill play with, cut off ill check out and phase?
Are these settings physically on the back of the sub or are they configuration options in the amp?
 

Etienne A

Active Member
If the sub is on the same "wall" as the front speakers one would normally set phase to 0. There's no correct setting ... you'll have to adjust this to you liking.

"Cut off" ... earlier you said that the sub is connected with 2 wires ... are you using the "speaker level in" on the sub? if so i would reccomend removing those and connecting the sub from the "sub out" on your amp/dvd combo to the "line in" on the sub (left ch.). Then once that's connected that way set the cut off to max & try again.
 

gblades

Active Member
also found a setting on the amp called "dynamic range"....


its currently off but the settings go:

2/8
4/8
6/8
full

what do they each do?

Thanks

I guess they are just fractions. I would just play with the settings. Try 2/8 and full and see which one has the lower dymamic and try that for a while. If you find that explosions etc... are now too quiet you can try a different setting. Without reading the manual I dont know if 'full' means full dynamic range or full dymanic range compression (which means the opposite).
 

newcomers

Active Member
the sub is on the opposite wall of the front speakers, and to my left

I cant change any wiring cos its all in the walls and under the floor.

Just double chancked and the sub only has 1 wire going to it, the other is the power cable :oops:
 

Etienne A

Active Member
From the manual

"DYNAMIC RANGE
If you want to watch a movie without disturbing others in
the house, you can reduce the dynamics (loud sounds) by
activating the dynamic range function.
Dynamic range compression can be selected in Dolby Digital
mode. Default setting is: OFF."
 

gblades

Active Member
And the 'cut off' and 'phase' are they settings on the amp or on the back of the sub?

Thanks for finding that Sniper. In that case if you set the dynamic range to full it should cure the problem you are having. If you find it has compressed the audio volume too much then try setting it to 6/8 or 4/8 etc...
 

newcomers

Active Member
they are on the back of the sub
 

The latest video from AVForums

Fidelity in Motion's David Mackenzie talks about his work on disc encoding & the future of Blu-ray
Subscribe to our YouTube channel

Full fat HDMI teeshirts

Support AVForums with Patreon

Top Bottom