Choppy Bass

[eyekyu]

I wanted to venture out of the AA sub thread...

my bass is choppy in low frequency's
its real annoying, i have no idea if this is normal... i doubt

anyways... Ive put the sub through Audyssey, stuffed it with poly fill, & tried different location in my room.

on the sub, my crossover is at max which is 130hz & 50% gain
on the receiver, LFE is at 90hz and -12db

any help
thanks

[erict]

Originally Posted by eyekyu

I wanted to venture out of the AA sub thread...

my bass is choppy in low frequency's
its real annoying, i have no idea if this is normal... i doubt

anyways... Ive put the sub through Audyssey, stuffed it with poly fill, & tried different location in my room.

on the sub, my crossover is at max which is 130hz & 50% gain
on the receiver, LFE is at 90hz and -12db

any help
thanks

That seems way low to me.

[eyekyu]

ive tired it at -8db as well, its the choppiness its very disappointing the higher i raise the bass. its not smooth, it pulsates.

[Big Daddy]

Originally Posted by eyekyu

ive tired it at -8db as well, its the choppiness its very disappointing the higher i raise the bass. its not smooth, it pulsates.

It is possible that the amplifier may have become defective. Contact the company and see if you can get a replacement. Alternatively, you can buy a new amplifier for around $100+ and replace the old amp.

[kareface]

Your gain is likely way to high. On what basis do you have it set as it is? Your gain will be relative to the voltage put out by your preamp. If your gain settings are too high you'll see clipping at lower frequencies.

[eyekyu]

Originally Posted by sentinel41

Your gain is likely way to high. On what basis do you have it set as it is? Your gain will be relative to the voltage put out by your preamp. If your gain settings are too high you'll see clipping at lower frequencies.

interesting...
if i mess with my gain, will i need to recalibrate?

should i leave my LFE to 90hz or bump that up as well

[erict]

Originally Posted by eyekyu

interesting...
if i mess with my gain, will i need to recalibrate?

should i leave my LFE to 90hz or bump that up as well

Yes you will have too. You have your gain at 50% AKA 12:00 o'clock which doesn't seem to high to me. Something seems whacked out to me. I would start all over by putting all your gains at 0 in you receiver and your sub's gain at 12:00 o'clock and re-run setup.

[progers13]

Originally Posted by erict

Yes you will have too. You have your gain at 50% AKA 12:00 o'clock which doesn't seem to high to me.

Nor me. Could be the amp is going, as several people have suggested.

[kareface]

You can't determine what 'high' would be considering you don't know the voltage output of his preamp. It could be his amp is on it's way out, but considering what he's describing is the textbook definition of amp clipping and the #1 cause of this is over gain then it would seem like a good thing to test prior to buying a new amp. Gain isn't a one setting fits all.

I'm not sure how your sub's LPF attenuation works but if you are using the amplifiers crossover then you should be able to set your subs crossover to 0. This is sub dependent tho, some subs that have the option will simply bypass the the crossover. This will only help if the crossover was negatively effecting the phase of the signal. Speaking of which, does your sub have a phase/delay dial? If your sub is out of phase it will also hurt the quality of the sound.

[eyekyu]

i do not have that phase dial, im gonna look into a new amp.
ive got the sub gain at about 45% and my fronts get better bass at certain points lol

[Yeha-Noha]

Originally Posted by eyekyu

I wanted to venture out of the AA sub thread...

my bass is choppy in low frequency's
its real annoying, i have no idea if this is normal... i doubt

anyways... Ive put the sub through Audyssey, stuffed it with poly fill, & tried different location in my room.

on the sub, my crossover is at max which is 130hz & 50% gain
on the receiver, LFE is at 90hz and -12db

any help
thanks

Please describe what you mean by choppy bass. Are you really hearing the subwoofer bottoming out which would be beyond annoying more like a horrible popping sound that you wouldn't be able to stand at all, or is it just that you have awful peaky bass response in your room?

[sarge1976]

Originally Posted by sentinel41

You can't determine what 'high' would be considering you don't know the voltage output of his preamp. It could be his amp is on it's way out, but considering what he's describing is the textbook definition of amp clipping and the #1 cause of this is over gain then it would seem like a good thing to test prior to buying a new amp. Gain isn't a one setting fits all.

I'm not sure how your sub's LPF attenuation works but if you are using the amplifiers crossover then you should be able to set your subs crossover to 0. This is sub dependent tho, some subs that have the option will simply bypass the the crossover. This will only help if the crossover was negatively effecting the phase of the signal. Speaking of which, does your sub have a phase/delay dial? If your sub is out of phase it will also hurt the quality of the sound.

What's the best phase option 0,90,180,or 270? I never understood what this meant so I always kept it at 180. Thanks

[kareface]

Originally Posted by sarge1976

What's the best phase option 0,90,180,or 270? I never understood what this meant so I always kept it at 180. Thanks

I'll try and explain this simply, sorry if it comes across as patronizing. It really depends on your setup, In 90% of cases 0 is the best option. Everything the original sound signal passes through adds a little bit of delay and changes the phase of the signal. You can also do this with speakers by hooking up the right and left connections backwards. A phase difference of 180 means that instead of your speaker pushing out when the signal tells it to, it sucks in because the signal is reversed at that point. To correct this problem with subwoofers companies add phase control that allow you to add even more phase to push the signal back around to 0. For most peoples setups their phase will likely not be push far enough away from 0 to justify using the phase control. You only want to use phase if you can push the signal back around to 0 (or closer to it then you are currently at).

Newer receivers have calibration functions that also test if your speakers are out of phase. I don't know if it works for subs tho. If you want help finding the phase of your sub I can help. I'd wager that 0 would be a better option then 180, but I can't know for sure with out having you run a test.

[kareface]

Originally Posted by eyekyu

i do not have that phase dial, im gonna look into a new amp.
ive got the sub gain at about 45% and my fronts get better bass at certain points lol

What do you have the receivers crossover set to? Are your mains set as large or smalls?

[sarge1976]

Originally Posted by sentinel41

I'll try and explain this simply, sorry if it comes across as patronizing. It really depends on your setup, In 90% of cases 0 is the best option. Everything the original sound signal passes through adds a little bit of delay and changes the phase of the signal. You can also do this with speakers by hooking up the right and left connections backwards. A phase difference of 180 means that instead of your speaker pushing out when the signal tells it to, it sucks in because the signal is reversed at that point. To correct this problem with subwoofers companies add phase control that allow you to add even more phase to push the signal back around to 0. For most peoples setups their phase will likely not be push far enough away from 0 to justify using the phase control. You only want to use phase if you can push the signal back around to 0 (or closer to it then you are currently at).

Newer receivers have calibration functions that also test if your speakers are out of phase. I don't know if it works for subs tho. If you want help finding the phase of your sub I can help. I'd wager that 0 would be a better option then 180, but I can't know for sure with out having you run a test.

Thank You very much for the explanation, I switched the phase to 0 and I'm going to see how it sounds for a little while. I do notice I hear more bass when I switch the phase around during different type of movies and music.

[dewd]

Originally Posted by eyekyu

I wanted to venture out of the AA sub thread...

my bass is choppy in low frequency's
its real annoying, i have no idea if this is normal... i doubt

anyways... Ive put the sub through Audyssey, stuffed it with poly fill, & tried different location in my room.

on the sub, my crossover is at max which is 130hz & 50% gain
on the receiver, LFE is at 90hz and -12db

any help
thanks

-12 may be the max your receiver will do. This means the gain on your sub is too high. Turn it down and re-run Audyssey.

Also, set the LFE to 120. This is not a crossover and should not be lowered.

[sarge1976]

Originally Posted by sentinel41

I'll try and explain this simply, sorry if it comes across as patronizing. It really depends on your setup, In 90% of cases 0 is the best option. Everything the original sound signal passes through adds a little bit of delay and changes the phase of the signal. You can also do this with speakers by hooking up the right and left connections backwards. A phase difference of 180 means that instead of your speaker pushing out when the signal tells it to, it sucks in because the signal is reversed at that point. To correct this problem with subwoofers companies add phase control that allow you to add even more phase to push the signal back around to 0. For most peoples setups their phase will likely not be push far enough away from 0 to justify using the phase control. You only want to use phase if you can push the signal back around to 0 (or closer to it then you are currently at).

Newer receivers have calibration functions that also test if your speakers are out of phase. I don't know if it works for subs tho. If you want help finding the phase of your sub I can help. I'd wager that 0 would be a better option then 180, but I can't know for sure with out having you run a test.

Hi, I tried setting the phase to 0 for a few hours and I noticed less bass from my sub so I set it back to 180. Does the crossover on my sub and on my reciever have to be set to the same hz? example- AVR-80hz and Sub-80hz, Thanks

[JBL4645]

Go over to home theatre shack http://www.hometheatershack.com/forums/rew-forum/ and sign up for there remarkable REW Room Equalizer Wizard. Your goal is aiming for flat near flat response that has less dips or nulls because nulls are just plan hopeless to address with EQ boosting that would but enormous stress on the amp with near clipping!

The odd peaks or two can be reduced over an average near flat response.

You can try moving the seating forwards and backwards to find the spot where the sub is near flat with less boom around 30Hz to 40Hz and possible 60Hz to 70Hz.

My room has the issues its not cinema auditorium size its common living room. I have the sofa placed fairly close to front at present to get near flat before EQ I have less nulls. If shift it back I’m in the few (null zones) that sucks the 40Hz range down and I need the 40Hz as most common lows in the LFE.1 are cantered around that mark.

It also keeps less power to drive some frequencies without over doing it. The lows that sound way too deep loud peaky high, needs less level! Then your stuffed for the other frequencies because there far too low down in level and you need those low tones.

[eyekyu]

Originally Posted by sentinel41

What do you have the receivers crossover set to? Are your mains set as large or smalls?

120hz, and the fronts are set to full band?

[eyekyu]

Originally Posted by dewd

-12 may be the max your receiver will do. This means the gain on your sub is too high. Turn it down and re-run Audyssey.

Also, set the LFE to 120. This is not a crossover and should not be lowered.

ive since re-ran audyssey since my 1st post. i can get as low as -15db, which is where audyssey puts the sub no matter when in my roon it is.
ive set my LFE to 120hz and the sub is at -8db