This site is supported by the advertisements on it, please disable your AdBlocker so we can continue to provide you with the quality content you expect.

Welcome to Our Community

Wanting to join the rest of our members? Feel free to sign up today.

Started building my (small) studio

Discussion in 'F.O.H.' started by Eduardo Apolonia, Dec 3, 2006.

  1. GeertSamuel

    GeertSamuel Member

    Joined:
    Jan 29, 2006
    Messages:
    2,179
    Likes Received:
    0
    Trophy Points:
    36
    Location:
    Nieuw-Buinen, The Netherlands
    Sad to see you selling your barefoots!
    I just had a demo of them!

    So if you put them up PM me...and hopefully by then I know how nice the tax office has been to me :)..

    Good to see you busy trying to find the ultimate mix surroundings and really nice to see pics and keeping this thread up-to-date..
     
  2. Soundlurker

    Soundlurker Member

    Joined:
    Nov 19, 2005
    Messages:
    3,733
    Likes Received:
    0
    Trophy Points:
    36
    Don't know if it was mentioned before but have you tried making a helmholtz resonator tuned to 130hz?
     
  3. John_C

    John_C formerly Skeksis268

    Joined:
    Dec 30, 2008
    Messages:
    3,457
    Likes Received:
    1
    Trophy Points:
    36
    Location:
    Coventry, UK
    Was just reading one of the white papers you linked to Eddy, really interesting stuff. The most important point I gained from it that hasn't been heard many many times before is that bass trapping is more effective when placed some distance away from the wall. I won't sully your glorious thread with nasty maths but it really does make sense

    have you tried stacking the rockwool up further from the walls? It might not be a practical solution, just might be interesting to see what difference in room response you get.

    Also, i thought i might attract your attention to this
    "Finally, I'll explain an interesting problem that happens when relying on low frequency response only for assessing the effect of placing bass traps. Sometimes moving a trap to a better location, or even adding another bass trap, can appear to make the response worse even though this is not really the case. The low frequency response at any given location in a room is the sum of the direct sound from the loudspeakers plus a large number of competing reflections from all of the room's surfaces. Some combinations create peaks, and some create nulls, but sometimes a reflection that would have made a null combines with one that would have made a peak. So together the result is somewhere between the two. If a trap reduces a reflection that had negated a null caused by a different reflection from somewhere else, the null will then appear. The null-causing reflection was always present but was partially cancelled by another reflection that has now been trapped. This is another reason that ETF's waterfall plots are the best way to assess the improvement by adding or positioning bass traps. With this type of graph, adding traps will always show the ringing being reduced, even if the raw response happens to be worse where you measure" from realtraps.com

    perhaps moving to waterfall graphs would be more effective for you when measuring the effect of moving bass traps around
     
  4. Eduardo Apolonia

    Joined:
    Sep 21, 2002
    Messages:
    983
    Likes Received:
    0
    Trophy Points:
    16
    Location:
    Algarve, Portugal
    I already have some people that are waiting for me to put them up for sale :)
    I'll let you know anyway, the biggest problem is shipping, because I want to sell the stands too.

    Thanks for the suggestion, that was one of the solutions but the tests confirmed that it wasn't the right solution.

    Thanks for the suggestion.
    I did try that and that monstrous basstrap mock up I did on the back should've helped a lot on the problem but as you can see the difference is too small compared to the size of the solution. If the problem came from the back, that basstrap mock up would make a lot of difference which didn't happen.

    I understand this info perfectly (and a lot more of other acoustical knowledge for what I've read in the past 4 months o_O) and that is totally right.
    The problem is that the null never disappeared so it can only be some kind of reflections that are creating the null.
    Now If I ever get to a point where the null disappears than I will have to check with the waterfall if the null didn't disappear because I have a resonance in the same frequency creating a illusion that everything is ok.

    But I can say that I've been looking at waterfalls too, I didn't post them because at this point, and considering their values the waterfall info is irrelevant at this point.

    But thanks for the reminder :cool:


    And thanks to all who are participating with ideas, all of them are very welcome. :cool:

    I'll post more info shortly because I'm already more ahead of what I posted earlier...
     
  5. Eduardo Apolonia

    Joined:
    Sep 21, 2002
    Messages:
    983
    Likes Received:
    0
    Trophy Points:
    16
    Location:
    Algarve, Portugal
    One of the first tests I did:
    Outside test to check monitor and mic flatness:

    This was the result:

    [​IMG]


    It was done like this but at 1mt (In this pic the mic is at 3mt)

    [​IMG]

    Attending the reflections from the floor and far walls it's a good measure



    So back to the tests inside the control room:

    I did more tests with the rockwool on the sides.
    I only put it on top of the racks but I think that it was enough to see that it wasn't doing much, 1 or 2 dBs in some areas as you can see on the graphic below

    Left Monitor
    Green Line - Without Rockwool on top of the racks
    Blue Line - With Rockwool on top of the racks

    [​IMG]

    Here you can see the rockwool on top of the racks, you can also see that by this time I have rockwool practically around all walls.
    And the dip is still there.

    [​IMG]

    [​IMG]

    I didn't try with the rockwool closer to the mic in front of the racks, because there was something that changed in the meantime that really did a big difference.
    I have 2 pairs of Adam monitors that were lent to me to try: S3X-H and S4X-H.
    The last measurements I did were with the S4s, but since they're heavy for me to move around by myself, a friend of mine helped me and I replaced one of the S4s for an S3.


    Now the good news:
    At this point was when I started to see the the light at the end of the tunnel!!!!


    When I started the measurements it caught my attention that there was a big difference on the right side where I replaced the S4 for the S3.
    The difference couldn't be just the monitor, so I saw that the front of the S3 was a little more to the back, since the monitor is less deep than the S4 it was pushed to the back as possible, but more importantly the S3 was lower than the S4 and that made a lot of difference.

    So I measured varying the height of the monitor and that gave a lot of different results.


    Orange line - Base of the monitor 89cm
    Red line - Base of the monitor 106cm
    Green line - Base of the monitor 123cm
    Blue line - Base of the monitor 140cm

    [​IMG]


    Pic of monitor inside the basstrap at 89cm (base) (Orange Line)

    [​IMG]


    Pic of monitor inside the basstrap at 140cm (base) (Blue Line)

    [​IMG]



    Then I did the same height variation but with the monitor outside the basstrap and went a little higher:


    Orange Line - Base of the monitor 89cm
    Red line - Base of the monitor 106cm
    Green line - Base of the monitor 123cm
    Blue line - Base of the monitor 140cm
    Black line - Base of the monitor 157cm

    [​IMG]


    Pic of monitor outside the basstrap at 89cm (base) (Orange Line)

    [​IMG]


    Pic of monitor outside the basstrap at 157cm (base) (Black Line)

    [​IMG]



    Then with the monitor outside the basstrap and at this height I varied the distance of the monitor to the Listening position.

    Black line - Just outside the Basstrap
    Red line - 15cm closer to the Listening position
    Orange line - 30 cm closer to the listening position.

    [​IMG]



    I think that all this info is starting to show that SBIR is the biggest problem, caused mainly by the distance from the ceiling/floor then adding the distances from front and side walls.

    More to come...
     
  6. MetalJonesy

    MetalJonesy more metal, more booze!!!

    Joined:
    Oct 18, 2007
    Messages:
    3,598
    Likes Received:
    0
    Trophy Points:
    36
    Location:
    Darlington/Manchester UK
    Eddy, this is some cracking insight!
     
  7. AntonioPetrole

    Joined:
    Jun 26, 2009
    Messages:
    1,974
    Likes Received:
    41
    Trophy Points:
    48
    Location:
    New Jersey
    i have been monitoring this thread for 2 years, eddy you are one sick dude, hopefully one day i can earn my way to a fraction of your studio lol. Much respect!
     
  8. under_rump

    under_rump New Metal Member

    Joined:
    Mar 23, 2010
    Messages:
    16
    Likes Received:
    0
    Trophy Points:
    1
    dude... kick..ass! really this takes home studios to another level man. excellent work ;)
     
  9. John_C

    John_C formerly Skeksis268

    Joined:
    Dec 30, 2008
    Messages:
    3,457
    Likes Received:
    1
    Trophy Points:
    36
    Location:
    Coventry, UK
    Very interesting. It seems finally you'll be able to make some progress!
     
  10. Eduardo Apolonia

    Joined:
    Sep 21, 2002
    Messages:
    983
    Likes Received:
    0
    Trophy Points:
    16
    Location:
    Algarve, Portugal
    Yes!!!
    After struggling with the Control Room acoustics for 4 months I'm finally more sure of what the problem is, and correction will be done in May. :cool:
    Until then I will have to connect everything back to do some unfinished work.
     
  11. Eduardo Apolonia

    Joined:
    Sep 21, 2002
    Messages:
    983
    Likes Received:
    0
    Trophy Points:
    16
    Location:
    Algarve, Portugal
    More testings...

    I filled the front right basstrap with the RW panels like this:

    [​IMG]


    The panels I placed inside the basstrap were the ones that were covering the side window.
    I took the panels from the other window too.

    Before:

    [​IMG]


    After:

    [​IMG]

    Then I covered the basstrap with the original RW panels:

    [​IMG]


    I did the testings and these were the results:

    Right Monitor (Base of the monitor at 157cm high)

    Green Line - Without Rockwool inside Basstrap
    Blue Line - With Rockwool inside basstrap (some panels taken out of side windows)
    Red Line . With Rockwool inside basstrap and on front (all panels taken out of side windows)

    [​IMG]


    Then I moved the monitor away from the mic 15cm and then another 15cm geting it the closest to the basstrap.

    Green Line - Closest to the Listening position
    Blue Line - 15cm farther from the Listening position
    Red Line - 30 cm farther from to the listening position.

    [​IMG]


    Then from the best position, (closest to the Listening position) I measured again varying the height, this time with the rockwool inside the basstrap.

    Orange Line - Base of the monitor 89cm
    Red line - Base of the monitor 106cm
    Green line - Base of the monitor 123cm
    Blue line - Base of the monitor 140cm
    Black line - Base of the monitor 157cm

    [​IMG]


    Then with the monitor in the lowest position (89 cm base) I measured again varying the distance from the Listening position:


    Orange Line - Closest to the Listening position
    Red Line - 15cm farther from the Listening position
    Black Line - 30 cm farther from to the listening position.

    [​IMG]


    I made some more measurements and I noticed that the worse place for the monitor is mostly half way from the position closest to the Basstrap to the position closest to the console referred on these measurements as - 15cm farther from the Listening position

    Then I did another measurement that I think that demonstrates that SBIR is a big problem here.
    I measured with the monitor at the same position but varying the mic position 15 cm and 30cm to the front.

    Black Line - normal mic position
    Red Line - mic moved 15cm to the front
    Orange Line - mic moved 30cm to the front

    [​IMG]

    Changing the monitor 15 and 30 cm made some drastic differences but changing the mic position the same amounts didn't made much difference.

    I'm almost sure that this confirms that the biggest problem is SBIR and not the modes, although the length modes influence too but in a smaller scale.

    This also explains why using the sub, this problem disappears. Since the low frequencies come near the floor, the low frequencies reflections couple with the direct sound from the sub and do not cancel at some frequencies.
    It has the same behavior as I tested having the monitor near the ceiling. And I didn't got so close to the ceiling as a sub is to the floor.
     
  12. barricade

    barricade Giggity Geschmougen

    Joined:
    Oct 31, 2007
    Messages:
    803
    Likes Received:
    0
    Trophy Points:
    16
    Tnx man... i learned a lot out of this!

    Now go record some stuff and post it!!!! :D
     
  13. kev

    kev Im guybrush threepwood

    Joined:
    Jun 16, 2004
    Messages:
    5,232
    Likes Received:
    0
    Trophy Points:
    36
    Location:
    Bristol, United Kingdom
    Bugger me sideways, this is some commitment to fixing a problem. I guess I should mix on cans. I was thinking of getting a flat response mic to have a look at what happens in my room, but it might drive me insane.
     
  14. AudioGeekZine

    AudioGeekZine arsehole know-it-all

    Joined:
    Jan 1, 2008
    Messages:
    3,470
    Likes Received:
    0
    Trophy Points:
    36
    Location:
    Vancouver
    holy fuck.

    Those pics make me die a little...your studio was so carefully designed and ended up with major acoustic problems...is there any hope for any of us!?
     
  15. JBroll

    JBroll I MIX WITH PHYSICS!!!!

    Joined:
    Mar 8, 2006
    Messages:
    5,919
    Likes Received:
    2
    Trophy Points:
    38
    Location:
    San Antonio, TX, USA
    Yeah... do what he did and hope for the best.

    Jeff
     
  16. John_C

    John_C formerly Skeksis268

    Joined:
    Dec 30, 2008
    Messages:
    3,457
    Likes Received:
    1
    Trophy Points:
    36
    Location:
    Coventry, UK
    Maybe I'm misunderstanding SBIR, but have you tried enclosing the monitor in rockwool? (leaving the front face open obviously)

    If the problem is reflections instead of standing waves then surely surrounding the monitor with a material that absorbs low frequencies you would reduce the spherical projection of low frequencies and reduce the reflections
     
  17. tgs

    tgs Elder

    Joined:
    Dec 18, 2003
    Messages:
    582
    Likes Received:
    1
    Trophy Points:
    18
    Location:
    Stockholm, Sweden
    Eddy, just wondering, where did you buy the insulation? I've had real problems finding the high density stuff here, the only place I know is in Lisbon and they are pretty expensive. Not to mention that I can only fit one pack in the car so it's 180km driving each round.

    In Sweden (where I'm originally from) I just go into the building material store, usually it's no problem at all. but when I asked in a store here they didn't know it and couldn't even order it for me.
     
  18. Eduardo Apolonia

    Joined:
    Sep 21, 2002
    Messages:
    983
    Likes Received:
    0
    Trophy Points:
    16
    Location:
    Algarve, Portugal
    :lol:

    If you're comfortable with it don't measure :lol:
    My problem is that I was never comfortable, and having to go to my car and other systems to decide if lows eq changes were good or bad wasn't very practical.
    The region (100-130hz) where I had/have the dip of 15-20dBs is a critical region.
    I had a better average low frequency sound in my bedroom.


    Depends on your luck :cool:

    The problem is that absorbing 100Hz waves with rockwool (that I had to work with) only isn't very easy.
    That's why that the most probable solution will be flushmounting the monitors and making a cloud on the ceiling.

    I'm still going to make a test with rockwool surrounding the monitor specially on top to see what happens

    I have bought some from a company named Silanto that you have in Lisbon and most from local construction companies.
    Just google Rockwool and your region and you'll find them.

    Don't go to AKI, MaxMat, Leroy, etc... They're more expensive and usually don't have much variety in densities.

    Where are you living now?
     
  19. GeertSamuel

    GeertSamuel Member

    Joined:
    Jan 29, 2006
    Messages:
    2,179
    Likes Received:
    0
    Trophy Points:
    36
    Location:
    Nieuw-Buinen, The Netherlands
    Apparently a lot of people are really pleased with soffit mounting. I know you're selling your Barefoots, but Thomas created them to also use them for soffit mounting.

    Don't know if you've alrleady seen this, but this is John Sayers' (www.johnlsayers.com) design.

    [​IMG]
     
  20. Eduardo Apolonia

    Joined:
    Sep 21, 2002
    Messages:
    983
    Likes Received:
    0
    Trophy Points:
    16
    Location:
    Algarve, Portugal
    Thanks for the tip once again. :kickass:
    It looks like an interesting design.
    I'll take a deeper look at it.

    I have seen what my portuguese acoustical consultant usually does to flushmount, it's a different concept and it looks like a great way of doing it after he explained to me the whole thing.
    I understand and believe firmly in his concept to flushmount and I can say that I'm a very skeptical guy :)

     

Share This Page