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Here is an REW measurement of my 4 DIYSG MBM's. Where do you think they are tuned at? I was thinking about 60hz. Should I get new ports and make them longer? What do you think these guys should play? About 40 to 80hz? Thanks for your time guys!
Are you using the 12” mbm or 15”?
 

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Put the tip of the microphone right up to the mouth of the port and post the response. Or put the microphone about 1/4" away from the dust cap and post the response.

What type of port(s) are you using? As in how many per cabinet, the diameter, and the length.
 

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** Man of Leisure **
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Here is a measurement of my 18" playing with my MBM's. What should I do about the big dip starting at 25hz and lower at 38hz?
You posted a combined measurement which showed a significant peak in the response starting at 25Hz. PEQ can normally bring down peaks like this, which would result in a relatively good response curve. Why are you continuing to obsess about the MBM port tuning when a simple application of PEQ could provide a perfectly good bass response?
 

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Hi All,

I am looking for advice. I am very new to REW.

I am trying to find optimal spot in the room for the single Sub I use. I took measurements and moved it alongside the opposite wall to where I am sitting. And it looks like there are two good spots for it both close to the corner (one in the corner (Sub-S18 files and one just the sub width next to it ).

So few questions:

1. Corner measurement has better FR (s18 file) response (or so I think) but next spot to corner has better waterfall graph (w14 file) and less ringing. Which should I choose?

The reading was taken at 86.5db. In AVR audyssey is off but I have set manually speaker distances by taking measurement with laser. I guess it is not important for subs only but I also made sub +L and +R and all 3 together and it is a mess :D. But I guess once I know which position you would prefer guys I could proceed with it to next steps.

I tried to adjust the graphs as per recommendations but I cannot find how to adjust vertical scale to 5db... sorry about that.

I am also including .mdat file from the measurements I took today in case somebody would like to take a look and see if he sees a better spot then those two.

The mdat linked below has measurements for positions 4 to 18 (where I singled out position 14 measurement 10 and position 18 measurement 27
https://drive.google.com/open?id=1APr3AbazrkP5i8YKlqYdF4Ht6jkvfA2k

And another mdat file with focus on position 18 only with correct addition of L, R and L+R to sub measurements to check phase. In this 2nd mdat file the first +L and +R measurements were taken with my laser measurement imputed into AVR and latest L and R measurements were taken with AVR distances set to 0 manually. Cross over is set to 100hz.
https://drive.google.com/open?id=1_69NSV2MYWONEgZyZ2JIa6AnbNbWtUho

Thanks
 

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I did start with room SIM. I am not entirely sure why would you send me back to room SIM when I already have real world measurements? And asking for advice on those.
 

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Option, you could use RTA function in REW. RTA stands for Real Time Analyzer. Look it up in the help files. This saves taking 300 measurements so to speak. Then you can fine tune with the sweep measurements. This is also effective for setting up speaker and listening position.
Looking at your graphs you could try as above, to try to find better location. You have a dip around the 30-43hz. Now you have a reference to try and beat.

FYI it's best to post multiple frequency graph using the all spl tab, it can be hard to compare with separate graphs for each measurement.

Also list what sub and receiver and speakers are been used, seems quite a high ish crossover.
Using a laser for speaker distances is fine but not good for sub distances. Normally AVRs aren't good at setting distances for subs. Sub distances are very important. But this can come after you found best place for sub.

As with the post with using Room SIM you started your post by saying I'm new and that person has given his or her thoughts, like me. If you follow this is entirely up to you.
 

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** Man of Leisure **
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Hi All,

I am looking for advice. I am very new to REW.

I am trying to find optimal spot in the room for the single Sub I use. I took measurements and moved it alongside the opposite wall to where I am sitting. And it looks like there are two good spots for it both close to the corner (one in the corner (Sub-S18 files and one just the sub width next to it ).

So few questions:

1. Corner measurement has better FR (s18 file) response (or so I think) but next spot to corner has better waterfall graph (w14 file) and less ringing. Which should I choose?

The reading was taken at 86.5db. In AVR audyssey is off but I have set manually speaker distances by taking measurement with laser. I guess it is not important for subs only but I also made sub +L and +R and all 3 together and it is a mess :D. But I guess once I know which position you would prefer guys I could proceed with it to next steps.

I tried to adjust the graphs as per recommendations but I cannot find how to adjust vertical scale to 5db... sorry about that.

I am also including .mdat file from the measurements I took today in case somebody would like to take a look and see if he sees a better spot then those two.

The mdat linked below has measurements for positions 4 to 18 (where I singled out position 14 measurement 10 and position 18 measurement 27
https://drive.google.com/open?id=1APr3AbazrkP5i8YKlqYdF4Ht6jkvfA2k

And another mdat file with focus on position 18 only with correct addition of L, R and L+R to sub measurements to check phase. In this 2nd mdat file the first +L and +R measurements were taken with my laser measurement imputed into AVR and latest L and R measurements were taken with AVR distances set to 0 manually. Cross over is set to 100hz.
https://drive.google.com/open?id=1_69NSV2MYWONEgZyZ2JIa6AnbNbWtUho

Thanks
First of all, I agree that position 18 (measurement 27) looks to be the best. I don't see a significant difference between the two waterfalls. I don't agree with Phillips752--there is nothing wrong with a 100Hz crossover. The sub+left measurement shows a good splice at the crossover point, while the sub+right shows a small dip at the crossover. Too bad you didn't measure sub+center (assuming you have a center speaker), because for content not in stereo, the center+sub interaction is most important. Not sure why you showed the Average measurements--averages are not very useful. The 10dB dip at 37Hz could be better, but expecting a sub response curve with only one sub to be perfect is probably not reasonable. Adding one or more subs would likely produce a better frequency response.
 

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Hi All,

I am looking for advice. I am very new to REW.

I am trying to find optimal spot in the room for the single Sub I use. I took measurements and moved it alongside the opposite wall to where I am sitting. And it looks like there are two good spots for it both close to the corner (one in the corner (Sub-S18 files and one just the sub width next to it ).

So few questions:

1. Corner measurement has better FR (s18 file) response (or so I think) but next spot to corner has better waterfall graph (w14 file) and less ringing. Which should I choose?

The reading was taken at 86.5db. In AVR audyssey is off but I have set manually speaker distances by taking measurement with laser. I guess it is not important for subs only but I also made sub +L and +R and all 3 together and it is a mess /forum/images/smilies/biggrin.gif. But I guess once I know which position you would prefer guys I could proceed with it to next steps.

I tried to adjust the graphs as per recommendations but I cannot find how to adjust vertical scale to 5db... sorry about that.

I am also including .mdat file from the measurements I took today in case somebody would like to take a look and see if he sees a better spot then those two.

The mdat linked below has measurements for positions 4 to 18 (where I singled out position 14 measurement 10 and position 18 measurement 27
https://drive.google.com/open?id=1APr3AbazrkP5i8YKlqYdF4Ht6jkvfA2k

And another mdat file with focus on position 18 only with correct addition of L, R and L+R to sub measurements to check phase. In this 2nd mdat file the first +L and +R measurements were taken with my laser measurement imputed into AVR and latest L and R measurements were taken with AVR distances set to 0 manually. Cross over is set to 100hz.
https://drive.google.com/open?id=1_69NSV2MYWONEgZyZ2JIa6AnbNbWtUho

Thanks
First of all, I agree that position 18 (measurement 27) looks to be the best. I don't see a significant difference between the two waterfalls. I don't agree with Phillips752--there is nothing wrong with a 100Hz crossover. The sub+left measurement shows a good splice at the crossover point, while the sub+right shows a small dip at the crossover. Too bad you didn't measure sub+center (assuming you have a center speaker), because for content not in stereo, the center+sub interaction is most important. Not sure why you showed the Average measurements--averages are not very useful. The 10dB dip at 37Hz could be better, but expecting a sub response curve with only one sub to be perfect is probably not reasonable. Adding one or more subs would likely produce a better frequency response.
Ok, so if one has large floorstanders 100hz is ok for a crossover?
Currently posting from a phone, so can't see mdat files.
 

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Ok, so if one has large floorstanders 100hz is ok for a crossover?
Currently posting from a phone, so can't see mdat files.
Absolutely! The subs should handle the low frequencies, not the main towers. And 100Hz, or 80Hz, is not an unusual crossover choice. I have PSB Synchrony Ones, a three-way speaker with 3 x 6 1/2 woofers, which measure -3dB at 30Hz. And I still cross them over at 100Hz.

Here is an exercise for you: set your left, right and center speakers to Large. Then measure full range 15-20,000Hz. Post your results here and I’ll show you how to calculate the best crossover based on the speakers’ frequency responses.
 
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Ok, so if one has large floorstanders 100hz is ok for a crossover?
Currently posting from a phone, so can't see mdat files.
Absolutely! The subs should handle the low frequencies, not the main towers. And 100Hz, or 80Hz, is not an unusual crossover choice. I have PSB Synchrony Ones, a three-way speaker with 3 x 6 1/2 woofers, which measure -3dB at 30Hz. And I still cross them over at 100Hz.

Here is an exercise for you: set your left, right and center speakers to Large. Then measure full range 15-20,000Hz. Post your results here and I’️ll show you how to calculate the best crossover based on the speakers’️ frequency responses.
Ok thanks long story but, unfortunately need to get new computer, once lockdown passes. Currently all posts are done via phone.

I have a old measurement (photo) of combined left and right main that hasn't changed. Hopefully this will give an idea.
Don't take any notice of the high end

Manufacture Speakers specs:
4way
2 x 6.5" woofers
35-20,000 +/-3db.

Ok looks like photo won't open this end.

To give idea starts to drop off @ 30hz steeply. Centre is similar and is the same model.
This is after EQ with Dspeaker Antimode 2.0 in the bass region.

I play 95% music. Can't remember last time I watched a movie.
I have the Minidsp 22A 2 channel dirac live to be inserted and more than likely use the Antimode 2.0 for the centre but this is for another day.

Thanks
 

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** Man of Leisure **
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I can’t open the photo either. The measurement would not be useful if it is mains+subs. So in the meantime you have to take my word for it—whether you listen to music or movies, your sub(s) are better positioned to reproduce frequencies below 100Hz regardless of how capable your mains are.

I have a MiniDSP 88A with the bass management module. I have configured two of the presets as follows: preset one has mains set to Small, crossover at 100Hz. Preset two has mains set to large with no redirected bass to the subs. I can play two-channel music and switch between the two presets to see whether the mains, with their three 6.5” woofers, playing without the subs sound as good as the other preset which utilizes the subs below 100Hz. Without a doubt, the preset that uses the subs sounds better.
 
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I can’️t open the photo either. The measurement would not be useful if it is mains+subs. So in the meantime you have to take my word for it—whether you listen to music or movies, your sub(s) are better positioned to reproduce frequencies below 100Hz regardless of how capable your mains are.

I have a MiniDSP 88A with the bass management module. I have configured two of the presets as follows: preset one has mains set to Small, crossover at 100Hz. Preset two has mains set to large with no redirected bass to the subs. I can play two-channel music and switch between the two presets to see whether the mains, with their three 6.5” woofers, playing without the subs sound as good as the other preset which utilizes the subs below 100Hz. Without a doubt, the preset that uses the subs sounds better.
Ok
Have to try this at 100hz, currently setup 80hz when using bass management. Velodyne DD15 needs to go into shop to get capacitor replaced (hopefully that's all) . The DD12 had the same problem 2 years ago.
Recalibrate the time alignment for subs as the crossover changed?
Actually can try with just the DD12 only.

Im able to change from high level to low level via the amp and remote. I have two Rel Strata 5s (high level) as well.

Thanks will keep you posted
 

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** Man of Leisure **
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Ok
Have to try this at 100hz, currently setup 80hz when using bass management. Velodyne DD15 needs to go into shop to get capacitor replaced (hopefully that's all) . The DD12 had the same problem 2 years ago.
Recalibrate the time alignment for subs as the crossover changed?
Actually can try with just the DD12 only.

Im able to change from high level to low level via the amp and remote. I have two Rel Strata 5s (high level) as well.

Thanks will keep you posted
The difference between 80Hz and 100Hz is minor. And no need to re-adjust sub-to-sub alignment if you experiment with a different crossover, but you need to re-visit the sub distance tweak.
 

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Ok
Have to try this at 100hz, currently setup 80hz when using bass management. Velodyne DD15 needs to go into shop to get capacitor replaced (hopefully that's all) . The DD12 had the same problem 2 years ago.
Recalibrate the time alignment for subs as the crossover changed?

Actually can try with just the DD12 only.

Im able to change from high level to low level via the amp and remote. I have two Rel Strata 5s (high level) as well.

Thanks will keep you posted
The difference between 80Hz and 100Hz is minor. And no need to re-adjust sub-to-sub alignment if you experiment with a different crossover, but you need to re-visit the sub distance tweak.
Thanks.
The posted measurement was full range only, with no subs. To give you idea both the RELs are crossed over at 30hz, measured.

When I ready to setup the 22A might call on you for tips if that's okay? Probably the same as 88A but 2 channel only and no bass management. 88A make a substantial improvement in your system?
 

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I did start with room SIM. I am not entirely sure why would you send me back to room SIM when I already have real world measurements? And asking for advice on those.
Oh didn’t know that. The idea to start with sim is to narrow down the 2..3 best locations to position the sub and take measurements.
 
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