Ok, so did the string trick.
- measured the distance from the acoustic axis of myspeaker to the tip of my measurement mic
- added the distance I gave you to that measurement ( 150,51 cm )
As we can see on the photos it is most likely the back-left window. Could also be my guitars.
Anyway, in this case is there anything that can be done? I have heavy curtains in front but that’s probably not enough?
You did the string trick incorrectly. Ill try to explain it here but I'm the first to admit that I'm horrible at explaining things!
- tape the string to the speaker as you've done
- measure the distance from the speaker to your microphone (let's call that distance "A")
- let's call the distance my calculator split out "B" -- this is ~150.5cm
- add A and B. A+B = C
- C is the length your string has to be. Mark that length on the string.
- tape the string at the mark to the tip of your microphone. You will now have a saggy long string strung between your speaker and your microphone.
- gently grabbing the string in the middle where it's saggy, try to find a place in your room where that string touches.
Essentially, the string is showing us the path of the sound as it traveled from your speaker, bounced off of something, and then eventually hit your microphone. Typically the surfaces in question end up being the floor, the ceiling, the wall, the desk, etc. All things in the front half of the room, living somewhere between the speaker and the microphone.
I hope I explained it well enough to understand. Please let me know, and I look forward to seeing what is causing the issue.
Once you find a potential surface causing the issue, place a small piece of insulation on the surface and take another measurement. We SHOULD see the reflection disappear from the filtered IR on your REW data.
Also, thanks for providing pictures. It sure helps us see what is going on!
Greg
It appears that you've made the mistake most people do. You started building without consulting this forum.
studioNorWay wrote:There I also have sorbathane (underneath, on the sides and at the top). Will the same principle also apply here? 15-20% reduced?
Yes, the 15-20% deflection is generally the optimum recommended by sorbathane for the best vibration damping.
studioNorWay wrote:Isn’t it normal to wall mount the amp from the speakers? I have seen studio projects on this site doing the same. Do they have special kind of speakers where the back amp is intended to be wall mounted? If so what kind am I looking for here?
Most of the adjustments on the speakers will be "set and forget". So you don't need constant access to them. Most studios will just fit them unaltered in the soffits and leave the settings as they are. Then plug in an xlr cable in the back and cut the end off it and solder it on a wall plate xlr/combo socket. Then you just plug your output from your daw/mixer/desk into the wall plate.
You can leave a removable panel on the side/front of your soffits, so you can reach in and adjust the settings if necessary.
That's what I'm doing in my studio
Dan
Stay up at night reading books on acoustics and studio design, learn Sketchup, bang your head against a wall, redesign your studio 15 times, curse the gods of HVAC silencers and door seals .... or hire a studio designer.
Isn’t it normal to wall mount the amp from the speakers?
It is handy to wall mount the amp. Typically if there is a problem with a speaker, it is either the power amp or a driver (speaker). Having the amp accessible and the fact that most drivers can be removed from the front of the enclosure, this allows easy repair. In speaker modules like yours, it is difficult to remove the speaker to access the power amp.
This also allows for easy tonal and volume adjustments. The only sensible way to adjust an active speaker with the amp module still mounted to the enclosure would be as Dan suggested which is to design your soffit such that there is an access panel.
Do they have special kind of speakers where the back amp is intended to be wall mounted?
For sure! For example, ATC Loudspeakers have kits for their speakers which allow you to remove the power amps. Also, many speaker manufacturers offer both active and passive versions of their speakers, passive allowing you to mount the power amp wherever you'd like.
Greg
It appears that you've made the mistake most people do. You started building without consulting this forum.
If you have access to a 3d printer, you might be able to print a copy of the amp board, with the heatsink etc. and mount the print to the aluminium back plate, then it should displace the same amount of air volume in the speakers and have a very similar frequency response.
That could be a way to continue to have the amps wall mounted, with these speakers.
Dan
Stay up at night reading books on acoustics and studio design, learn Sketchup, bang your head against a wall, redesign your studio 15 times, curse the gods of HVAC silencers and door seals .... or hire a studio designer.
Gregwor wrote:You did the string trick incorrectly. Ill try to explain it here but I'm the first to admit that I'm horrible at explaining things!
I hope I explained it well enough to understand. Please let me know, and I look forward to seeing what is causing the issue.
Thanks Greg. You explained perfectly. I will do it again as described above and post the result. 2 Time's The Charm
Gregwor wrote:
Once you find a potential surface causing the issue, place a small piece of insulation on the surface and take another measurement. We SHOULD see the reflection disappear from the filtered IR on your REW data.
Will do!
Gregwor wrote:
Also, thanks for providing pictures. It sure helps us see what is going on!
Thanks. Pictures do say allot and I will try to keep them coming.
Gregwor wrote:
For sure! For example, ATC Loudspeakers have kits for their speakers which allow you to remove the power amps. Also, many speaker manufacturers offer both active and passive versions of their speakers, passive allowing you to mount the power amp wherever you'd like.
Greg
Thanks for the tip Greg. I will check them out.
John Sayers wrote:here you go ATC speakers with amps mounted below.
Waka wrote:
Yes, the 15-20% deflection is generally the optimum recommended by sorbathane for the best vibration damping.
Naice! I will do 15-20% on them all then.
Waka wrote:
If you have access to a 3d printer, you might be able to print a copy of the amp board, with the heatsink etc. and mount the print to the aluminium back plate, then it should displace the same amount of air volume in the speakers and have a very similar frequency response.
That could be a way to continue to have the amps wall mounted, with these speakers.
That’s insane! but brilliant!
Yes, I do have access to a 3d printer. why didn’t I think of that? I will try to make a replica of the power amp and mount it on the aluminum plate.
Ok, so I have done the string trick for the second time. Hopefully I’ve done it correctly this time. Let me know if I’ve missed something.
It seems that I have reflection on a wood frame at the front ceiling cloud. And also, many places on the right-side slot wall. So now you want me to add insulation over all the spots, right? Then do the measurement again?
Hi Bjorn, looks like it's the side wall slats. Won't be the ceiling, as the path is not direct to the microphone. Consider a ray from the speaker, at that point the ray would bounce to the side wall again and then probably to the floor etc before getting to the microphone.
Just place a slab of insulation horizontally across the slats at the mix height and remeasure.
studioNorWay wrote:That’s insane! but brilliant!
Yes, I do have access to a 3d printer. why didn’t I think of that? I will try to make a replica of the power amp and mount it on the aluminum plate.
I would love to see this if you pull it off!
Dan
Stay up at night reading books on acoustics and studio design, learn Sketchup, bang your head against a wall, redesign your studio 15 times, curse the gods of HVAC silencers and door seals .... or hire a studio designer.
John, that studio is gorgeous! Also, are you safe from the fires in Australia? It breaks my heart to see the nightmare that is happening down there
Bjorn, I totally agree with what Dan said regarding your cloud. It isn't in "line" with the path the audio would take on it's way from the speaker to the microphone. It has to be the side walls. Great detective work my dude!
Greg
It appears that you've made the mistake most people do. You started building without consulting this forum.
Gregwor wrote:
Bjorn, I totally agree with what Dan said regarding your cloud. It isn't in "line" with the path the audio would take on it's way from the speaker to the microphone. It has to be the side walls. Great detective work my dude!
Thanks Greg! Side wall noted.
Waka wrote:Hi Bjorn, looks like it's the side wall slats. Won't be the ceiling, as the path is not direct to the microphone. Consider a ray from the speaker, at that point the ray would bounce to the side wall again and then probably to the floor etc before getting to the microphone.
Just place a slab of insulation horizontally across the slats at the mix height and remeasure.
Naice!:) I will remeasure with a slab of insulation horizontally across the slats at the mix height.
Waka wrote:
I would love to see this if you pull it off!
I have already started the process .
So, I have a good amount of work ahead of me now. I will try to post as I move along the next few weeks.
1. Remove block from left speaker.
2. Insert / mount original untampered speaker on the left side and do a measure for reference.
3. Finish the fusion 360 replica of speaker amp and 3d print two copies.
4. Mount 3d copied speaker amp on the back plates and re-mount speaker inside enclosure with 15-20% Sorbothane deflection.
5. Re-mount speaker cabinet enclosure and with 15-20% Sorbothane deflection using the turnbuckles.
6. Put everything back in place.
7. Add slab of insulation horizontally across the slats at the mix height and remeasure.
I will do it again as described above and post the result. 2 Time's The Charm 
