Basement Studio in Berlin - construction phase!

Hi All, Here is the Construction phase - design phase is here: viewtopic.php?f=1&t=20323&start=0 Just started but wow seems like a lot of work - and deadline soon as my first child is due in May! Feel like I'm going mental down in this basement sometimes! So thankful for this forum and esp. the contributions of the wonderful wizard, Soundman2020 Stuart! a lot of amazing help coming out of Santiago !! :D More soon!

Keep in mind this is from recycles materials, hence the weird colours :)) I have put most of the second layer on the inner leaf now. The gap you see in the top middle is for windows (1 x 16mm, 1 x 12mm laminated glass, toasty cheese). The gap below that is for a flatscreen. The white areas are approximately where the soffits go. I have made all the HVAC baffles, put the first 25mm ceiling layer on, and will make some pictures soon!

Just started but wow seems like a lot of work -

Welcome to the wonderful, relaxing world of studio building! :)

and deadline soon as my first child is due in May!

Wow! A studio AND a baby, at the same time! Man, do you have your work cut out for you!

Feel like I'm going mental down in this basement sometimes!

Then you are feeling like a perfectly normal studio builder... insanity is part of the project. Sane people don't do what we do... :)

So thankful for this forum and esp. the contributions of the wonderful wizard, Soundman2020 Stuart!

:oops: Thanks for the kind words!

After treatment

Looking good, but are you sure you sealed all the gaps and cracks???

Keep in mind this is from recycles materials, hence the weird colour

Oh no! You used the wrong colors! That will totally trash your sound! :) (Sorry, couldn't resist...)

The gap you see in the top middle is for windows (1 x 16mm, 1 x 12mm laminated glass, toasty cheese).

Ahh yes, the best kind.

I have made all the HVAC baffles, put the first 25mm ceiling layer on, and will make some pictures soon!

Promises, ... promises... Like we say around here: "Pics! Or it didn't happen!" :) Seriously, it's looking pretty good. As soon as you have the room fully sealed, do your first REW test, as the baseline, so you have something to compare against as you add each part from there on, to make sure everything is working. - Stuart -

Thanks for your encouragement Stuart! Here's a bunch more photos!

It's progressing well, it seems, but I'm rather skeptical of your soffits so far... I don't see enough beefy framing to hold it all together rigidly... You might want to consider adding some more framing, to make sure that everything (especially the front baffle) is supported very firmly. - Stuart -

Hey Stuart, thanks for your feedback - I will be addng more bulk when the real soffit goes in! The speaker boxes will be 2 x 20mm MDF braced by 60*80mm stud. This is just a temporary - I have an urgent studio session and I moved out of my old studio last week so will stuff both cavities full of rockwool in plastic bags and go for speakers on stands for the next week or so!

Hi Stuart and all! So I'm back after a somewhat complicated birth, and needless to say I haven't progressed much! But I have a healthy baby boy which is super cool :) So I'm returning to my soffits and a bit perplexed - I haven't started to install anything since the last set of photos and now I'm somewhat confused about progressing. We went through the soffit design somewhat, atnd yes I will be beefing it up with plenty of beams and mass. But what I'm curious about is that this soffit design seems to do the opposite of this one: viewtopic.php?f=12&t=718 So I assume these are somehow different approaches. I also saw another approach where the speaker is on a shelf just more or less in the middle of a superchunk. Now for the sake of clarity (and not having measured the room yet - I will do so at some point soon I hope), which of these approaches is the most useful here? And easiest perhaps :) Remember the room is quite small, approx 300*260cm... I'm slightly concerned as I have seen it mentioned that soffit is often not the way to go for small rooms... And what about speaker upgrading - ie I might at some point exchange my Tannoy Reveal 6D for Adam F7... so I would like to leave the speaker cavity a bit larger to allow for this. Should I do so and just pack the gap with wood sheets or rockwool etc? Thanks! Tim

So I'm back after a somewhat complicated birth, and needless to say I haven't progressed much! But I have a healthy baby boy which is super cool

Congratulations, Tim! Wow! A new addition to the family AND a new studio! Lots of "news"...

So I'm returning to my soffits and a bit perplexed - I haven't started to install anything since the last set of photos and now I'm somewhat confused about progressing. We went through the soffit design somewhat, atnd yes I will be beefing it up with plenty of beams and mass. But what I'm curious about is that this soffit design seems to do the opposite of this one: . . . . . So I assume these are somehow different approaches.

Correct. "There's more than one way of skinning a cat", as the saying goes (a rather strange saying, actually!). There's more than one way of building a soffit.

I also saw another approach where the speaker is on a shelf just more or less in the middle of a superchunk.

That's not a soffit! It's just a speaker stuffed into a superchunk. Whoever would call that a "soffit mount" would have to be pretty ignorant of both soffits and bass traps! The concept of a proper flush mount ("soffit mount") is very simple: remove the speaker from the room, in order to eliminate the artifacts caused by having the speaker inside the room. To do that, you mount the soffit in the wall. Except that you angle that part of the wall a bit, in order to get the right angle for the speaker. The surface of the wall acts as an "infinite baffle": it replaces the tiny front "baffle" (front panel) of the speaker cabinet itself, with a much larger one. The larger it is, the more it acts like an "infinite" one. There are multiple benefits to doing that. In order to do that well, the speaker must be held very firmly in position, by a very tough, solid, rigid frame, such that it cannot transmit any of its vibrations into the frame or the baffle.... or alternatively, it can be "floated", for the same purpose. "Floated" in the sense of being fully suspended on resilient mounts, such that it cannot transmit any of its vibrations into the frame or the baffle. In both cases, the baffle itself must be very massive: very heavy. So you are looking at two different ways of accomplishing the same thing. You can chose whichever you prefer. Here's a link to a room I did recently, where the speakers are floated on a suspension system: viewtopic.php?f=2&t=20471 . The only problem with this approach is that you have to "tune" the suspension system such that the resonant frequency is at least an octave below the lowest frequency that the speaker will be producing, and preferably two octaves. In this room, the mount is designed to have a resonant frequency of 14 Hz., so it isolates above 28 Hz (one octave). The speakers can theoretically go down to about 34 Hz, but they are paired with a couple of subs in that room, and are crossed over at 86 Hz., which is nearly 3 octaves higher than the resonance. So there's no issue there with the speaker causing the soffit itself to vibrate, as you can see from the acoustic measurement graphs.

Now for the sake of clarity (and not having measured the room yet - I will do so at some point soon I hope), which of these approaches is the most useful here? And easiest perhaps

"Easiest" is to use John's method: Mount the speaker very solidly and rigidly, with very tough framing and a rigid box around it. That works very well, as you can see from John's rooms. I prefer to do the "floated suspension" approach when I can (which isn't always possible).

Remember the room is quite small, approx 300*260cm... I'm slightly concerned as I have seen it mentioned that soffit is often not the way to go for small rooms...

Actually, a soffit can benefit a small room just as much as a big room, if not more. The only problem is that it takes up space. As long as there's enough space to do that and still have a usable room, then soffits mount is the way to go.

And what about speaker upgrading - ie I might at some point exchange my Tannoy Reveal 6D for Adam F7... so I would like to leave the speaker cavity a bit larger to allow for this. Should I do so and just pack the gap with wood sheets or rockwool etc?

In the link I gave above, I originally designed the soffits for exactly that situation: the studio owner expected he would need to upgrade his speakers at some point. It happened sooner than he expected, when one of his old speakers started making strange noises. The way I had designed it, there's a removable "tray" that actaully carries the speaker, and it is large. It is solidly bolted into the soffit, so by removing the bolts you can slide it out, and slide in a new "tray" that has the new speaker already mounted in it. So that's what the owner did: Build the new "trays" while the studio was still in use, mount the new speakers inside the rays at the correct height and angle, then one day in a a few hours of down time he popped out the old trays, popped in the new trays, and carried on running. (We later spent a lot of time re-tuning the room for the new speakers, as you can see in the graphs). - Stuart -

Hi Stuart, great, thanks for clearing that up, much clearer (and thanks for the congratulations too!). Also I've gotta say that link is amazing! What a brilliant piece of work you pulled off there! Here are a few pics of the current framing - the front has also been put on but I don't have a picture of that handy... So here's a question... the background is that the amp section of my Tannoy Reveal 6D's died on one speaker and I decided to bits the bullet and buy some Adam A7X's.. I would fix the Tannoy's but as the glue they used goes conductive after a number of years (something I discovered after building the flushmounts rrr!) I decided there was no long term payoff there... So thing is, the Adam's are 3mm smaller in the vertical and 9mm smaller in the horizontal axes. Should I fill this gap with MDF layers or dense rubber/foam? As you stated below:

Soundman2020 wrote:

In order to do that well, the speaker must be held very firmly in position, by a very tough, solid, rigid frame, such that it cannot transmit any of its vibrations into the frame or the baffle.... or alternatively, it can be "floated", for the same purpose. "Floated" in the sense of being fully suspended on resilient mounts, such that it cannot transmit any of its vibrations into the frame or the baffle. In both cases, the baffle itself must be very massive: very heavy. So you are looking at two different ways of accomplishing the same thing. You can chose whichever you prefer.

The baffle is pretty heavy I must say, 24mm MDF. However, how should I pack out the sides/top of the gap that is now created?

"Easiest" is to use John's method: Mount the speaker very solidly and rigidly, with very tough framing and a rigid box around it. That works very well, as you can see from John's rooms. I prefer to do the "floated suspension" approach when I can (which isn't always possible).

I have to say, the difference is amazing! It sounded like a washing machine in there before, and I'm sure its got some way to go but WOW - so much tighter! Yes I am very naughty for not measuring the room yet (I will do so, promise) but certainly by ear it's two different rooms! Thanks for the input, really feel like I'm getting somewhere finally thanks to your input! :) Tim

OK so here are the first measurements of the room - I haven't taken pictures yet and had to start using the studio prematurely as a firiend from NY came to finish an EP with me... Weirdest thing, when I do a sweep on REW with my ADAM A7X's, up at the top end it has this piercing phasing sound like two sinewaves interfering and crossing eachother - pretty sure its from the speakers, not the room... Can see it on the graphs. Anyway, here are the graphs: And project file is available here: http://bit.ly/2hQUHki My experience of the room is that it is very bassy and boomy - which would make sense given the spike around 60hz... aside from that, the treble is very bright, which could be just lack of soft treatment in the room, but also new adam's and my ear getting used to it/them not being burnt in yet... Any input greatly appreciated! Thanks Tim

You did your tests at 106 dBC??? :shock: Can you still hear OK? Did you cook your speakers? Probably not, as the A7X should be able to handle that OK, but WOW! Why did you set your level 100 times higher than standard? Calibration level is 85 dBC, not 106... Or maybe you didn't calibrate REW properly? Or maybe your hand-held sound level meter is way off? Maybe you had it set to "A" and had REW set to "C"? Well, whichever way it went down, you need to go back and calibrate REW correctly, then repeat your tests. Also, I have no idea what that high-pitched screeching is, but it certainly isn't correct! It needs fixing. Are you getting that on both speakers or only on one of them? If only on one, then the speaker is shot and needs to be fixed/replaced. If on both then the problem is probably elsewhere in your signal chain (or possibly both of your speakers are shot... but unlikely.) - Stuart -

WHAT WAS THAT?!?!? I CAN'T HEAR YOU??!!!! :oops: but seriously, I calibrated REW to the levels that it asked for in the calibration process... but obviously something is right here... I'll try again! It wasn't ridiculously loud (although I did block my ears for the treble section!) So many variables in that program! Must have made a mistake along the way... Back to the drawing board! T

One question: What is the make and model of the hand-held sound level meter you used to calibrate REW? Something to check: The meter must be selected to "C" weighting, and "Slow" response. - Stuart -

Soundman2020 wrote:

One question: What is the make and model of the hand-held sound level meter you used to calibrate REW?

Hi Stuart, it's the Dayton Audio UMM-6 USB Measurement Microphone. It also came with a serialised calibration file. It's my first time measuring a room so still finding my way around it, thanks for the tip I'll check it out!

Just had another look at your measurements for the room you built mentioned above in viewtopic.php?f=2&t=20471 - amazing! Well, anyway looks like my measurement is a bit more realistic now - thanks for the tips! Here is the .mdat file http://bit.ly/2hJmHu8 Concerned about that massive dip around 7k - snd of course the spike 60-70Hz... Given I haven't put in the rear bass traps (which will be solid rockwool with acoustic spiky foam over the top - is that OK to do that?), I assume that will resolve some of the bass issues? In any case, the whole thing looks pretty spiky! Any ideas on where to start? Thanks!

Concerned about that massive dip around 7k -

That probably isn't really there at all: it's just due to the mic being exaclty mid way between the speakers. Your ears are several inches apart, so they would never "see" that. Do a test with JUST the left speaker on, and another with JUST the right speaker on.

of course the spike 60-70Hz... Given I haven't put in the rear bass traps (which will be solid rockwool with acoustic spiky foam over the top - is that OK to do that?), I assume that will resolve some of the bass issues?

It won't fix it completely, but it will help a lot.

In any case, the whole thing looks pretty spiky! Any ideas on where to start?

Start with the bass traps, and the first reflection points, and the cloud. Do REW tests after each one. At this point, do you have your speakers and mic set up correctly? The soffits are built, and the speakers are set in the correctly, with the righ settings on the back panel? Do you have any other treatment in the room? - Stuart -

Hi Stuart, thanks for the tips - will try and remeasure each speaker (been away for a few weeks!)

Soundman2020 wrote:

Start with the bass traps, and the first reflection points, and the cloud. Do REW tests after each one. At this point, do you have your speakers and mic set up correctly? The soffits are built, and the speakers are set in the correctly, with the righ settings on the back panel? Do you have any other treatment in the room?

soffits are built, speakers are snug in there, back panel settings are just at 0 for all. There is currently no treatment in the room - will start with bass traps as you suggest, then remeasure. Unfortunately the ceiling height limits putting a cloud in, and also the window in the front to the outside worls goes to the ceiling so don't really want to block that off. Any suggestions on a thin profile treatment for the ceiling? Thanks! Tim