how fix bass problem

[darklight]

Hello everyone, I don't know anything about waterfalls and the other graphs in REW but I can see from the below picture that I have big bass problems. I don't have a dedicated room. I am using my living room as my home theater. It is made of concrete blocks and cement and it opens into the bedroom and into the kitchen. its kind of sort of like a studio apartment. What would you guys recommend I can do to try and fix or alleviate this problem?

 

[darklight]

No one has any suggestion?

 

[ddude003]

My suggestions are to post an .mdat with your sweeps... And tell us about your room dimensions, speaker positions and any room correction via bass and wide band absorbers and if you are using any Room Correction DSP...

 

[JStewart]

Are you in a country with 50Hz electric cycle cause that ringing at 50Hz could be ground hum. 35Hz could be refridgerator, HVAC, or some other mechanical noise going on. If you take another sweep and it’s still there, then use REW’s RTA to measure the ambient noise in the room and see if it shows up.

 

[darklight]

My suggestions are to post an .mdat with your sweeps... And tell us about your room dimensions, speaker positions and any room correction via bass and wide band absorbers and if you are using any Room Correction DSP...

I am using a Denon X6500H with Audyssey XT32 with DEQ turned on and 4 sub woofers all different brands. I got an SVS PB 1000 Pro a Behringer B12000D-Pro, an old passive JBL MP418S used as nearfield and a Definitive Technology BP2002TL tower with built in 12 in powered sub. I am using only one of the def tech subs. all this connected to a MiniDSP 4x4HD.
My room is 14.09 feet wide by 18.68 feet long and 7.63 feet high ceiling, but as I said before it opens into the bedroom and into the kitchen. Because of my weird room distribution. I had to work things backwards. The two Def Tech towers are now my surrounds and my 2 BP2X surrounds are now my fronts. and I am not using a center channel. I know this a terrible idea but I had no choice. The couch we just move there when we are going to watch a movie otherwise it is at its main place which is at the front.

Why do I attach the REW .mdat file and it doesn't show up in my post?

 

[darklight]

Are you in a country with 50Hz electric cycle cause that ringing at 50Hz could be ground hum. 35Hz could be refridgerator, HVAC, or some other mechanical noise going on. If you take another sweep and it’s still there, then use REW’s RTA to measure the ambient noise in the room and see if it shows up.

I am in the Dominican Republic. We use the same electrical system as the USA. The refrigerator was on when I took those sweeps so you could be right. I don't remember if the AC was on. But these sweeps were only taken for me to experiment tie aligning the speakers

 

[JStewart]

I am in the Dominican Republic. We use the same electrical system as the USA. The refrigerator was on when I took those sweeps so you could be right. I don't remember if the AC was on. But these sweeps were only taken for me to experiment tie aligning the speakers

Again you can use REW’s RTA to measure without a sweep to see what the noise is in the room or on your system. USA is 60Hz. A quick google search revealed the Dominican Repubic can be 50-60Hz. In that range a frequency is ringing without diminishing at all in 300ms on your waterfall. This strongly suggests an electrical signal, present in your set-up, that you are picking up in the measurement. Not that you need to do anything about it. Just understand if so, you won’t fix it with room treatments or EQ.

 

[John Mulcahy]

Why do I attach the REW .mdat file and it doesn't show up in my post?

The file may be too large.

 

[linuxonly]

Why do I attach the REW .mdat file and it doesn't show up in my post?

I had exactly the same problem. Zip it first and upload the zip. It works.

 

[darklight]

I had exactly the same problem. Zip it first and upload the zip. It works.

thanks I will try that. Though I don't know if it will make much differences.I think perhaps this is the wrong area to ask these bass questions as I don't see many people giving advice

 

[ddude003]

It is difficult to give good advise without enough data to go on... Thanks for the drawing and more information about your kit... Maybe add your full kit to the More section as I didn't see that you had subs or MiniDSP... Still waiting for that .mdat file...

 

[darklight]

It is difficult to give good advise without enough data to go on... Thanks for the drawing and more information about your kit... Maybe add your full kit to the More section as I didn't see that you had subs or MiniDSP... Still waiting for that .mdat file...

I cant seem to be able to attach the .mdat file even after zipping it. John suggested that it is because it is too large. Zipped its 31.7 MB So now I donr know how to upload it.

 

[John Mulcahy]

Zipped its 31.7 MB

A single measurement is 31.7 MB zipped? That's huge. Please post a screenshot of your analysis preferences.

 

[darklight]

A single measurement is 31.7 MB zipped? That's huge. Please post a screenshot of your analysis preferences.

it was not a single measurement. It was a 4.1 speaker measurement but since I am just asking about the bass I've decided to just delete all the other measurements and only keep the LFE channel

 

[darklight]

It is difficult to give good advise without enough data to go on... Thanks for the drawing and more information about your kit... Maybe add your full kit to the More section as I didn't see that you had subs or MiniDSP... Still waiting for that .mdat file...

here is the LFE .mdat

 

[John Mulcahy]

In the "Impulse response calculation" section of the Analysis preferences change "Keep full IR" to "Truncate IR after 1.7 s", that will make your mdat files about one tenth the size and discard all the IR noise that is currently being retained.

There's no need to measure the sub beyond 1 kHz, that again just adds noise to the result when you go past the sub's high frequency limits.

A few EQ filters could reduce the major resonances in the response, but you could also try placing the sub at different positions along the wall at the bottom of your diagram to see how the response changes.

 

[paul8]

I am using a Denon X6500H with Audyssey XT32 with DEQ turned on and 4 sub woofers all different brands. I got an SVS PB 1000 Pro a Behringer B12000D-Pro, an old passive JBL MP418S used as nearfield and a Definitive Technology BP2002TL tower with built in 12 in powered sub. I am using only one of the def tech subs. all this connected to a MiniDSP 4x4HD.

Just curios, if you are using Audyssey why would you need a MiniDSP? Also, how does your system sound? If you like the sound I wouldn't worry much about the measurements - not all problems you see in REW can be actually heard.

 

[darklight]

Just curios, if you are using Audyssey why would you need a MiniDSP? Also, how does your system sound? If you like the sound I wouldn't worry much about the measurements - not all problems you see in REW can be actually heard.

The miniDSP is used to managed the 4 subs and EQ them to get as flat as possible. I think it's sounds ok but I know my room has lots of echo because of the center wall so I know it could sound better.

 

[darklight]

In the "Impulse response calculation" section of the Analysis preferences change "Keep full IR" to "Truncate IR after 1.7 s", that will make your mdat files about one tenth the size and discard all the IR noise that is currently being retained.

There's no need to measure the sub beyond 1 kHz, that again just adds noise to the result when you go past the sub's high frequency limits.

A few EQ filters could reduce the major resonances in the response, but you could also try placing the sub at different positions along the wall at the bottom of your diagram to see how the response changes.

Thanks for the great advice. I will make the changes right away.
As for the EQ I tried equing all 4 subs with the REW EQ and then implement them with the MiniDSP. I could not get a flat enough curve because of how bad my room is but I will try next with MSO and see how that works for me.

 

[paul8]

The miniDSP is used to managed the 4 subs and EQ them to get as flat as possible. I think it's sounds ok but I know my room has lots of echo because of the center wall so I know it could sound better.

I assume you have excluded your subs from Audissey then? Otherwise you might be double processing bass frequencies, could introduce all kinds of issues.

 

[darklight]

I assume you have excluded your subs from Audissey then? Otherwise you might be double processing bass frequencies, could introduce all kinds of issues.

Actually I did not exclude Audyssey. I purposely ran it through Audyssey so that it further flatten the signal.Audyssey sees the 4 subs as one unit and I've read and seen videos that say that could be a good thing.

 

[ddude003]

About the only thing I could add at this point would be that you could add some room treatments... Bass absorbers and wide band absorbers and Diffusors... I always recommend room treatments first then some EQ/DSP...

 

[darklight]

About the only thing I could add at this point would be that you could add some room treatments... Bass absorbers and wide band absorbers and Diffusors... I always recommend room treatments first then some EQ/DSP...

Thank you I think that is probably the best thing to do a this time. I just have to figure out which panels and where on the room to put them.