DIY In-{1/2m-Brick}-Wall (HT) Speakers !!!

[Medenyx]

Hello & Greetings, from Senta in Vojvodina, Serbia, Ex-Yugoslavia!

Very happy, to join this apprise community, of true devotion to its goals!
Also, a bit of a surprised, due to the 'limitations' of the DIY in-wall speaker activities at all (the web?!?)!



Namely, all in all: there is 'only' the type of "tin" in wall mounting, regardless of the wall structure (wood, ... , mostly), ...

My wish is, my own idea: to create a (near-)Perfect Home Theater, better than even a convectional ones, (if possible, ...), in my main room at my house.



This 'room', is quite a room.


With its dimensions of: 7m x 6m, and 3.8m high, it would be the perfect HT for my taste, not to mention my girlfriend and a taste of my choosy friends at all.
The house itself is considered "big and strong", mainly to its thick walls: at least 1/2meters (50cm)! (Some of the outer walls are even thicker!)



Did I mention? The walls are made from solid brick!



My pride!



And the source of many problems, too. Mostly, the lack of a knowledge ...



My idea, of making in-brick-wall (L,C,R) speakers, DIY style (:after I "sculpture out" holes in the (brick-)wall, lay down and fix the top-bottom-&-Both sides of the 'in wall' speaker boxes (from a 25mm MDF), to the (square hole of the) wall (permanently!), and at last: place the front panel of these (3) speakers (30mm MDF), with a corresponding drivers (dual bass & mid-range, and a tweeter), in the same plane with the wall, attaching it to the (strongly) fixed inner ‘frame’, ... etc.



I am more than interested in this project, but there is not a single one to share with me this kind of experience Building and Mounting the speakers. (Crossovers, just to mention).



Any idea, of a side dipole and a rear bipolar speaker: construction and, or mounting?!? (system should be: 7.2)


Sub-woofer in the brick wall … also! There is a lot of In-the Brick-Wall Space!
Only!
Not in the room floor!


The main idea is to match at least thx ultra 2 specifications (… only, because I am modest).


Please, give me any suggestions, or opinions according this matter, only if it is constructive – of course! From beginning of DIY to The End!


Thanks in advance, for all the suggestions! Much appreciated.

Kind Regards,
Medenyx

P.S.: Sorry for any mistakes in my English. They are not made on purpose, or deliberately. Thx.

[Arty]

depending on where you sit, and a few other things you may end up with close to no bass if you do that.

other than that the idea is verry nice.

[Top Shelf]

Good for you! #1 make sure you don't affect the structural integrity of the walls that you intend to hollow out. #2 be careful of any dust that comes out . I hope you're going to build wood boxes into those walls to avoid morter dust being loosened from the bricks and either going into the voice coils or out through any ports.
Perhaps set a subwoofer up where your final listening position is and then wander around the room and find the most extended yet un-boomy position( hopefully its near one of the thicker walls) and that will give you an idea as to where to place the in wall sub. Unless you're going to use multiple subs in different positions to even out the room response.
Have fun doing this and please provide pictures for us to drool over
You may probably have a problem with this room being too live from all the high density wall surfaces unless you plan to use "wall treatments" after the fact.

[Arty]

might help more than a lot to cover the opposing walls with some heavy carpet to avoid reflections. Otherwise it may -or may not, depends on a few things- cancel out a large portion of bass notes if you are in the middle of the room.
While it may allso create a boomy-boost if you are sitting right at the wall opposing the speakers.

[Medenyx]

Originally Posted by Arty

might help more than a lot to cover the opposing walls with some heavy carpet to avoid reflections. Otherwise it may -or may not, depends on a few things- cancel out a large portion of bass notes if you are in the middle of the room.
While it may allso create a boomy-boost if you are sitting right at the wall opposing the speakers.

Thanks Arty!

For your support.

Do you really think, that the bass could (even) disappear in a room with this proportions? My experience is (almost) quite the opposite (tested with a few home made (DIY) unknown-less-known drivers, speakers).
But you are completely right!!! Especially about "a lot to cover...".
Not to mention the importance where you are ... , I am, ... sitting! And that is: in front of the rear wall, by the quarter of the length, between rear to front wall (precisely 1.5m to the rear, 4.5m to the front, and of course: 3.5m to both of the sides of the room).

But if so, (thinking about the disappearing bass), I remembered, to another idea for a solution!
A so called : "water wallpaper" ... , or more correctly: " liquid textile wallpaper " ( FLOTEX - liquid textile wallpapers ... ).
"They are" well known about their sonic superb behavior. So they say, ...
Have you an opinion about that, my friend?

Soon enough, I will prepare some pics of "the progress", I promise, but until then, I am gladly waiting for any suggestion, or any good idea, maybe a corresponding suggested site(s), all, as a representation, of a good attention.

Kind Regards,
Medenyx

PS: The floor of the room is 30mm thick (clean) wood, and is equipped with quite a heavy furniture, also curtains, ... , but still, not over-equipped.

[Medenyx]

Originally Posted by Top Shelf

Good for you! #1 make sure you don't affect the structural integrity of the walls that you intend to hollow out. #2 be careful of any dust that comes out . I hope you're going to build wood boxes into those walls to avoid morter dust being loosened from the bricks and either going into the voice coils or out through any ports.
Perhaps set a subwoofer up where your final listening position is and then wander around the room and find the most extended yet un-boomy position( hopefully its near one of the thicker walls) and that will give you an idea as to where to place the in wall sub. Unless you're going to use multiple subs in different positions to even out the room response.
Have fun doing this and please provide pictures for us to drool over
You may probably have a problem with this room being too live from all the high density wall surfaces unless you plan to use "wall treatments" after the fact.

Thank you, Jeremy, for your answer & for your concern.

But, the structural integrity of the walls would be hard to affect, cause of the structure itself, and my (so-so modest) knowledge in masonry. My intention is to completely renovate this old, but stable house, by the way, no matter how neglected it is.

Wood boxes, are self understood! Each side (top, bottom, left & right) should be assembled to the wall from inside the speaker box, as I mentioned it (...after I "sculpture out" holes in the (brick-)wall, lay down and fix the top-bottom-&-Both sides of the 'in wall' speaker boxes (from a 25mm MDF), to the (square hole of the) wall (permanently!)...), but I only thought, that the back of the speaker box-in-a-brick-wall should stay open, without its rear 25mm / MDF, due to a deliberately left (deapest) 1 row of brick, to the outside of the 50cm wall (, about 15cm wide), that I would filled with some sound absorbers. So, there is not a chance for any morter dust, to be loosen from the bricks, and make any damage!
But thanks to you, I will definitely rethink , to put a back (rear box) 25mm MDF side to the speaker box, before permanent installation, or further wall mounting. Thanks for the notice!

"The in wall sub" idea is similar to my "mathematical attentions". But, due to that, did you see one of our DIY colleagues site:
Woefwoef7a
Ok! It is not an in-a-brick-wall sub, more like in-a-door-jamb-sub, ... , but I liked it. What do you think?
I was actually thinking about using 2 (multiple) subs, positioned on the opposite side one of each other, in the (almost) middle of the left & right wall (literally). But my budget will decide, ...

Again, "wall treatments" should I use. (Why do I sound like Master Joda? Same English teacher? Maybe.) As I mentioned ( FLOTEX - liquid textile wallpapers ... ), I am eager to hear your opinion about (this or any other) liquid textile wallpaper.

Hopefully, I will achieved mu goal, and thanks to all of a good attention, (from you), we could all exchange our constructive experiences, and who knows, even celebrate our attaining a score result(s):

Kind Regards,
Medenyx

P.S.: I am open to any audio, true Hi-Fi suggestion(s), about calming the "to live" walls to put them to their place.
No! I won't place wood materials all around the walls of the room.

[Arty]

well, it seems You are comfortable with reflections and wave lenght.
Do some math, the reflections from the opposite wall will cancel most of the bass if you are right at the middle of the room.

A heavy carpet will work just fine, no need for over expensive stuff.
I would recommend You first build the sub properly, before putting it into the wall.
And the cabinet should have all sides covered by wood. You will not regret that step for sure. Allso You should use something that can take the resonations between the brick wall and the cabinet. Otherwise with time You are going to face some issues for sure.

Build a nice cabinet then power it up, and put Your hand on it. You will be quite surprised how mutch even the most strudy cabinet can vibrate.

Actualy i done something close to this. I mounted car speakers into a drywall wall.
but thats a bit different.

Anyways it is more than hard to predict the results You will get.
Verry important to have a proper driver selection for this task, otherwise the sub will not integrate well with the rest of the system.

The reason behind it is:
time delay.
To put it simple, the ssub will be further from You then other speakers.
So the sound has to travell a bit more. This can allso do funny things, it depends a lot on xover point, driver and box selection and order of the filters used.
You may -hard to tell if , but it can happen with ease- may have to use allpas filter(s) on main speakers to delay them to get a proper time alligment.

What You are looking for is not impossible to manage.
Nothing wrong with the concept, in audio everything You do -or not do- is a compromise.
Setting a sub in the wall offers a lot, if done right.

About time alligment of speakers, i will link an article that describes quite a lot of handy things for You.
SB1980-3way
the mentioned sound scattering will be no issue with Your inwall sub.
but, You must make sure the speaker is sitting in the front baffle, and not sticking out. (double front baffle is anyways adviced.)

[Medenyx]

For starters, cause I promissed, here is a quick diagram of the brick room adaptation for Dolby, DTS and THX recommendations (hopefully all in one):

[Charles Darwin]

Good size room, my lucky friend!

Big enough to use some bass traps without cramping your style.
With the dimensions you stated I would look particularly at 50Hz (7m),57Hz (6m) and 90Hz (3.8m) and their multiples where your room will have standing waves which may need damping out.

Just google (diy) bass traps they can be made cheap and easily disguised depending on your interior design ideas. There are many feasible approaches as with everything it all depends on circumstances.

[Medenyx]

Originally Posted by Arty

well, it seems You are comfortable with reflections and wave lenght.
Do some math, the reflections from the opposite wall will cancel most of the bass if you are right at the middle of the room.

A heavy carpet will work just fine, no need for over expensive stuff.
I would recommend You first build the sub properly, before putting it into the wall.
And the cabinet should have all sides covered by wood. You will not regret that step for sure. Allso You should use something that can take the resonations between the brick wall and the cabinet. Otherwise with time You are going to face some issues for sure.

Build a nice cabinet then power it up, and put Your hand on it. You will be quite surprised how mutch even the most strudy cabinet can vibrate.

Actualy i done something close to this. I mounted car speakers into a drywall wall.
but thats a bit different.

Anyways it is more than hard to predict the results You will get.
Verry important to have a proper driver selection for this task, otherwise the sub will not integrate well with the rest of the system.

The reason behind it is:
time delay.
To put it simple, the ssub will be further from You then other speakers.
So the sound has to travell a bit more. This can allso do funny things, it depends a lot on xover point, driver and box selection and order of the filters used.
You may -hard to tell if , but it can happen with ease- may have to use allpas filter(s) on main speakers to delay them to get a proper time alligment.

What You are looking for is not impossible to manage.
Nothing wrong with the concept, in audio everything You do -or not do- is a compromise.
Setting a sub in the wall offers a lot, if done right.

About time alligment of speakers, i will link an article that describes quite a lot of handy things for You.
SB1980-3way
the mentioned sound scattering will be no issue with Your inwall sub.
but, You must make sure the speaker is sitting in the front baffle, and not sticking out. (double front baffle is anyways adviced.)

Hello Arty!

Well, ... , not that comfortable, , ... nobody will be at the middle of the room(!), I said, ... anyway: thank you for your advices.
As always, a good advice is always welcome, and well accepted!

For a resonances between the brick wall and the cabinet, I tough about several long & strong fixed screws in to the brick(s) from the inner speaker box, and a "fixing" / "hardening" (dry) foam, that becomes (very) stiff after it comes in touch with the air (for the sides, as for left, same for the right, anyway). For the back or rear of the box (and a narrow place to the rest of the remain of the outer wall) should be stiffed with regular thick, but pressed sponge. And, the most important bottom of the speaker box -> should be cemented (with screws from inside the MDF speaker box) or should I say "paved"? At last, for the remain thin space between the top of the speaker box and a brick wall, well, I thought of a another type of a dry and ultra strong concrete (extra cement, less water, ... etc.).
Any concrete comment, on that?
Thanks in advance.

Also, thanks for an article. As soon as I get some time, I'll get to it deeper! Cause, as I said, I am beginning to renovate this huge house, trying to recondition it. For a living in it, of course.

"... double front baffle is anyways adviced."- said you;
Advice taken! Subs will be made of double 30mm MDF. (60mm MDF, is hopefully, more than enough! ) Thanks, again.

What to do, about (more than) possible standing wave's in this room?
Suggestions?

Kind Regards,
Medenyx