JBL Synthesis - Room Design and Treatment

[Valentin]

Ti

go ahead with the room there is always options for placing subs

there are many option one is do a column and place the sub near the ceiling

there it works exactly the same as the floor and the bottom part of the column can be your bass trap

etc etc etc

remember that you have the sedec 4000 with will help you alot in this range

[Valentin]

Here is a room i designed a couple of year ago

it has a flat RT .3 +- .03 second time from 80hz up

today i would have done some thing a bit differently but it is a great sounding room

esthetics was the way the client wanted not my choice there so many options that can get you good results

[Titanium Dome]

Here is a room i designed a couple of year ago

it has a flat RT .3 +- .03 second time from 80hz up

today i would have done some thing a bit differently but it is a great sounding room

esthetics was the way the client wanted not my choice there so many options that can get you good results

Looks cool. Can you recall the room dimensions?

That room is very attractive, but my intent is to make the room disappear both visually and sonically. I can afford great sound and vision, or I can afford a beautiful room, but not both.

[Valentin]

it is a 6.30m x 3.9m x 3.40 that would be 20.6ft x 12.8ft and 11ft high

it is not that big


that room is extremely neutral sonically and it sure disappears
imaging is pinpoint no bass boom a lot of envelpment etc

acoustics does not mean to have bad aesthetics

[BMWCCA]

Here is a room i designed a couple of year ago

Are you the gentleman with the hair, or without?

[Valentin]

none

the gentleman without the hair is the owner and the one with hair is a reviewer from home tech magazine
i am the one in the anechoic chamber

[Valentin]

Ti dome is in excellent hands with the help of JBL synthesis crew

thy are the one that should be doing the suggestion for the alternative locations or did you have to contract a acoustical consultant.

who did the acoustic calculations and design for your room

or did just tell you to put absorbers in the side walls a some bass traps in the corners and diffusers in the back

are these bass traps Helmholtz, slat or diaphragmatic or just fiber
are you treating the ceiling do you have carpeted floor etc

do you have plan with your sweet spot and the angles for speakers it would be very nice if you can post them

[Allanvh5150]

There is definitely nulls in your room
one thing is that your room is dead in the upper frequencies and another is in the bass region

Feel free to wave the BS flag. Without listening you will never know but feel free to pop round for a listen. I am sure that you would be pleasantly surprised. In the listening position you can not hear the room at all. With a movie playing the room dissapears visually as well. As for the 230USD of fibreglass, it was actually carpet. Non parallel walls and ceiling with carpet on all surfaces has taken care of 95% of the problems. In a home environment the other 5% is not even worth talking about. As an engineer for a great many years I have used the best gear, run huge systems inside and outside and used some pretty amazing recording studios. Feel free to use an RTA to "hear" problems that you cany hear. My ears are always the judge andthey have served me well.

Allan.

[Valentin]

Non parallel walls and ceiling with carpet on all surfaces has taken care of 95% of the problems

none parallel walls do not make modes disappear it just make them less predictable you need to absorb the energy and carpet is not going to be very efficient below 300hz

what i do agree is that what the end user hears is what is important

As an engineer for a great many years I have used the best gear, run huge systems inside and outside and used some pretty amazing recording studios

so all the acoustical treatment ($$$) in does amazing studios is too fix that 5%


some room have good acoustical qualities it depends in great many factors type of construction type of furnishing shape size etc etc

but too say that any room with carpet in all of the walls and celling is going to fix 95% of the problems is simply wrong

a non environmental room may be a good place to mix in but it is far from a grate place to reproduce recorded music

Feel free to use an RTA to "hear" problems that you cany hear

if some one is in favor of the correct reflextions it is me , totally deaden a room is not the best solution for a pleasure listening
and does refection appear in the rta
measurements are important if you now how too interpret them and do the right type of measurements for the right reasons

[Allanvh5150]

none parallel walls do not make modes disappear it just make them less predictable you need to absorb the energy and carpet is not going to be very efficient below 300hz

what i do agree is that what the end user hears is what is important



so all the acoustical treatment ($$$) in does amazing studios is too fix that 5%


some room have good acoustical qualities it depends in great many factors type of construction type of furnishing shape size etc etc

but too say that any room with carpet in all of the walls and celling is going to fix 95% of the problems is simply wrong

a non environmental room may be a good place to mix in but it is far from a grate place to reproduce recorded music



if some one is in favor of the correct reflextions it is me , totally deaden a room is not the best solution for a pleasure listening
and does refection appear in the rta
measurements are important if you now how too interpret them and do the right type of measurements for the right reasons

Without getting silly, all I said was that in a normally built room, carpet from floor to ceiling will fix 95% of the problems in the room. For all intents and purposes I can not hear the room. I aint gonna fix what I cant hear. Anything better in a "home" environment is pointless. It will cost and extra $1000 to get to 96%, an extra $10000 to get to 97% and so on. If you feel the need to pick holes in something that you have never listened to, feel free to do so.

[JBL 4645]

This is typical movie theater sound treatment -- seen round the world in thousands of theaters. It's rigid fiberglass, or mineral wool, panels attached to the wall and then covered with acoustically-transparent fabric that is pleated and mounted over the panels.

The fiberglass panels shouldn't represent a health concern for anyone once they are mounted and behind the fabric. Firstly, the rigid panels are quite dense and only shed when brushed against. And all the loose fiber gets shaken out during installation. Plus the fabric on top keeps in any remaining fibers. As long as you take precautions for installation (or have someone else handle that) and clean up the space thoroughly before "moving in," you should be fine.

But then, as others have mentioned, there are alternatives. The most popular being cotton panels that are made from recycled blue jeans.

Right gotcha

The fibre sheets are really inexpressive in small quantities.

There’s not much of an echo than slight shape sound when clapping my hands so less would be more in small room rather than overdoing it (yes or no)?

I know what it sounds like when clapping my hands in the VUE when no ones around the sound decays really fast, as I was there this Thursday, after I saw Star Trek at the Empire in THX I then saw Wolverine at the VUE in THX.

[JBL 4645]

Without getting silly, all I said was that in a normally built room, carpet from floor to ceiling will fix 95% of the problems in the room. For all intents and purposes I can not hear the room. I aint gonna fix what I cant hear. Anything better in a "home" environment is pointless. It will cost and extra $1000 to get to 96%, an extra $10000 to get to 97% and so on. If you feel the need to pick holes in something that you have never listened to, feel free to do so.

Unless of course you go around building sites, nicking it!

I’ve seen some cinemas using carpet attached to walls.

ABC Westover road screen 1 upstairs has carpet stuck to the back wall, while the sides is drapes or part of the same material for the curtains.

ABC screen 2 again carpet stuck to rear walls, it’s a naff sounding cinema that I wouldn’t take my cat in there to spray the place over!

ABC screen 3 has carpet stuck to side and rear walls.

Odeon Westover road screen 1 has carpet stuck around the auditorium and the floor god damn some for god sakes clean it! It hasn’t been washed in 15 years or so the place really sticks its second worst to the guy across the road with the cats pissing over his home.

I tried carpet on the walls years ago and it really sucked I still had this sound like sound buzz. I just nailed the carpet to wall it was fast and easy and sucked.

I don’t think I’ve got enough room to attach fibre boards to the side and rear walls without losing a few inches of the rooms dimensions. It sounds better than my mates it rumbles it roars it jolts it kicks and slams with good clear LCR front and wicked surrounds.

It might be doable when I shift the rack of equipment into the bedroom. I might take different approach. The window most defiantly needs blocking due to traffic and other sounds filtering in on loud busy day.

[JBL 4645]

So, the room is now officially a "problem room." It's thwarted me in every effort to make it a better place for the Synthesis® gear.

My thought process is something like this:

1. Put the Synthesis® gear in the room in a temporary install, with
no more physical changes to the room so it can be returned to regular
use.

AND

2. Save up for a year or so and finish the unfinished basement area
and install the SynthesisR system permanently in there. I have a bid
for about $28,000 for the primary construction.

OR

3. Sell the Synthesis® system and recover some of my money, plus end my grief.

Chris Neumann talked me down from the ledge (as in, "Wait, don't jump! Things aren't that bad.") and agreed to work with me on a temporary install, which hopefully will go quickly. Even at that, it should be a night and day improvement over the beautiful Performance Series system that was in there.

There will be more as the saga continues.

So you have but a few hours called hard sweating and beating the crap out of what ever that is looks like concrete?




Beat it in and save $28grand rather than giving it to some mug pardon the expression.

If you think your room’s problematic I have sodden chimney breast that sticks out by 18 inches but I’ve solved that as and when I block off the front left corner, (sometime around early June after I pick the LCD projector up and start knocking up base platform up front).

Don’t you have mates that can get you the building materials for next to nothing?

Anyway you need to get yourself with a sledgehammer beat the what ever it is in for 1 hour while another mate takes the rubble outside to the dust bins or dig a hole in the garden and ditch it.

Then switch around while he beats it in and you take down the rubble. You need the British on this not an American. No pun.

Maybe small jackhammer would work fast but that room looks doable, rather than wasting $28grand in basement.

You’ve got some pucker JBL there and your not focusing on which room is easy to knock up in next to no time. was going to use the bedroom as you remember but it was located blow other bedrooms and was bit of problem at night the Earth moved while the neighbours below where having sex.

So I moved it back in the bedroom and I moved it around or tested it twice in the living room and once in the bedroom I think. The only issue was it was too small. I have to build a proper stud wall above near around the door and do away with that piece of wood I have stuck over it for the surrounds.

I’d like to slyly beat the chimney breast in and dump the bricks in dustbin at night. Then get the wall skimmed and plastered but the tubes inside the breast hmm. Its not doable. So I have to work around it.

[hjames]

So you have but a few hours called hard sweating and beating the crap out of what ever that is looks like concrete?

Maybe small jackhammer would work fast but that room looks doable, rather than wasting $28grand in basement.

Ash, I'm pretty sure that concrete is structural - its the FOOTER, and it can't go away ...
I think thats TiDome's designer's problem ... and his!

The other possibility would be to build up the rest of the wall so its all at that same level,
put stuffing behind it to deaden any reverberations ...

Okay, it's the d@#%ed footer. It's not going anywhere, and it continues around underneath the shelving to the right.

The stub wall is bolted to the floor. The studs would have to be cut out, and then we'd only gain 4". Not worth it.

[jblsound]

but too say that any room with carpet in all of the walls and celling is going to fix 95% of the problems is simply wrong

a non environmental room may be a good place to mix in but it is far from a grate place to reproduce recorded music

if some one is in favor of the correct reflextions it is me , totally deaden a room is not the best solution for a pleasure listening
and does refection appear in the rta
measurements are important if you now how too interpret them and do the right type of measurements for the right reasons

That's the truest statement I've seen in this thread. I've listened to music in what I would call a totally deaden room. And it totally sucked.

I don't like a really live room either. Read that as listening to a boom box at full volume in a home still under construction, with bare sheetrock walls, bare concrete floors and completely empty.
A good room to me is something at the mid-point of those two extremes.