New build, isolation req. Control room enviroment

[Purelythemusic]

Ha,

Yes I have done an REW test, will post later....I was worried that having speakers in the (combination of mdf and birch ply laminated) cabinets would cause the cabinets themselves to produce some stong resonances but possible bescause they are mostly filled they are relatively massive and I’m not really going to listen above 70db, they don’t seem to be causing any major transission problems between rooms (which is a big concern as the in laws are in the next room and hypersensitive to bass).

The sound in the room is pretty good but the bass range sounds a bit muddy to me. The graphs show a stong mode the width of the room (the direction the speakers are firing unsurprisingly) especially noticeable at the sofa : ) 52hz corresponds with about 3.3m which is the distance between cabinets and the sofa wall.

Graphs soon : )

[Purelythemusic]

The living room graphs as promised.

No treatment in the room. 1st plan is to wrap some rockwool in Camira fabric (which I have kicking around from an office acoustic job) and pretty much encase the speakers in, leaving a gap somewhere for some air flow (even though they're passive, I think they should have something) at the back of the cabinet hole (I have 2 x 25mm dia. holes in the back panel, for cable and some air. When done they shouldn't physically be connected to the cabinet and I hope to reduce a lot of the effect of having ported speakers in a box in a cabinet!...We'll see!

Oh and Stuart, my toddler will know the value of equipment by the time she is 3 and a half so won't be causing any problems... although she is showing early signs of being a drummer....despite being left a nice Warwick bass by my late father!

[Purelythemusic]

Stuffed rockwool at the back 100mm, Rockwool under speakers and on one side (couldn't fit it both sides and above...

Results are more or less as expected/hoped, shows slightly less bulge at the 52hz range, though has caused it to be more peaked. 20db variation is better than 30db though. It sounds less muddy so that's good : )

I look forward to treating the back wall when we're building panels for the studio! Just need to finish hallway then render, then we're go!

[Purelythemusic]

Hi,

Just a quick update...

I have been reading a fair bit on this brilliant forum and as has been said before, the more you investigate, the more questions pop up!

I’m at the beginning of the HVAC journey, a long and important road! I’m getting some help from a friend in Australia who’s job is commercial HVAC designer but he has worked on studios before... the climate is almost opposite but I hope a lot of the same principles apply!

I am also deciding on monitors to buy which will enable me to start designing my front wall, soffit mount design, listening position and angles for front and side walls to get the required RFZ at that position...well around that position.

I am trying to research as much as possible without asking questions that have been answered countless times by generous contributors! ...but...

In my mind I plan to mount the HVAC ‘inlet from outside’ and ‘exhaust from inside’ points and silencer boxes up high in the corridor as I should have sufficient height for them not to be in the way...obviously depends on the HVAC design as to the size and feasibility.

My long winded question is; is there a common place in the control room for the 2 silencers required in there... For symmetry it would have to be front or back walls right, or one each side up high? If the back of the room needs massive amounts of absorbtion then it may take up needed space there so it behind the soffits best if you bring the soffits in to the room a bit...ooo but then the mix position might be getting close to the midway point! So maybe up high in front of the soffits in the centre but surely that would create early reflections!

Apologies for the rambling!

[Soundman2020]

My long winded question is; is there a common place in the control room for the 2 silencers required in there... For symmetry it would have to be front or back walls right, or one each side up high?

I normally bring in the cool air supply at the rear end of the room, from the ceiling, and take out the warm stale air from the front of the room, above or between or inside the soffits.

If the back of the room needs massive amounts of absorbtion then it may take up needed space there

Unless you use hangers for the bass trapping, which means that you have plenty of space between them where air can flow down from the registers, into the room...

so it behind the soffits best if you bring the soffits in to the room a bit...ooo but then the mix position might be getting close to the midway point! So maybe up high in front of the soffits in the centre but surely that would create early reflections!

Or take put the registers ABOVE the soffits...

Keep your silencer boxes outside of the room itself: put them in the ceiling space, between the inner and outer leaves...

- Stuart -

[Purelythemusic]

Thanks again Stuart!

I'll add the silencer boxes to the drawing to start trying to mock up their positions. I think I would like the silencer boxes themselves to be accessible...I don't know if this is seen as best practice? I'll certainly have standard filters at the AHU if a central system is what I end up with...and then maybe an additional particulate filter at the silencer inlet side, if access is not usually best practice this might make the usable space larger... I won't know what size boxes I'm looking at until the HVAC system and spec is known right? I'll guess oversize at something like 300mm high, 600mm wide and 2m long.

To clarify my ignorance of HVAC systems, let me explain my current understanding and please appropriately correct at will:

I have read posts about HVAC systems that are

- mini split systems - where there is no ducting run, there is an external unit mounted sort of back to back with the internal output unit. These units take in the air in the room and condition it either warmer or cooler. They do not provide fresh air from outside or exhaust stale air from inside...this would need to be factored in a separate system.

- Ducted systems which have a central pusher and puller of air - Air Handling Unit, they can (I hope) incorporate, heating, cooling, humidity control, fresh air in, stale air out and be connected to HRV or ERV systems (or can they be all in one and incorporate everything!

The humidity of the system should maintain 43 - 45%
The system should not be oversized so it short cycles, therefore not having the chance to control humidity.
The duct systems should have minimum angles and length, curving angles wherever possible.
Silencers should be on the inside of the external leaf where fresh air comes in and exhaust out (x 2 silencers) and on the outside of the internal leaf where conditioned air enters the room and stale air is removed (x 2 silencers)

Eeek, I am sure to be wrong in something here!

The space I have between the outer face of the inner leaf ceiling and the inside face of the outer leaf ceiling is at least 300mm.

Thanks again,

Tom

[Soundman2020]

I think I would like the silencer boxes themselves to be accessible...I don't know if this is seen as best practice?

It's not really necessary. As long as you have good filters on your duct system ends, and clean them regularly, there's no real reason to need to open up the boxes, just like there's usually no need to open up an HVAC duct.

I won't know what size boxes I'm looking at until the HVAC system and spec is known right?

Right! You need to do a LOT of math first, to arrive at that point of being able to dimension your silencers. Better get out your calculator, slide rule, AND abacus...

- mini split systems - where there is no ducting run, there is an external unit mounted sort of back to back with the internal output unit. These units take in the air in the room and condition it either warmer or cooler. They do not provide fresh air from outside or exhaust stale air from inside...this would need to be factored in a separate system.

Right, but the outdoor unit ("compressor" or "heat pump") does not need to be back-to-back with the indoor unit. They can be quite a distance apart. The system usually comes complete with a "pipe bundle" that is maybe 5 to 10 meters long, and you can get extensions for that, if you need more distance. Check the specs of the units you are interested in, to find out what the maximum distance is. Some can go long, others can't, but you should normally have at least 5m or so to play with.

- Ducted systems which have a central pusher and puller of air - Air Handling Unit, they can (I hope) incorporate, heating, cooling, humidity control, fresh air in, stale air out and be connected to HRV or ERV systems (or can they be all in one and incorporate everything!

The actual AHU in either case (ducted or non-ducted) is pretty much the same in principle. Here's a comparison of two typical units:

HVAC--mini-split-ahu-and-typical-indoor-unit-ducted-and-unducted-non-ducted-compare-NOLBL.jpg

The one on the left is a typical non-ducted unit, that you would have on the rear wall of your studio if you go that path. The one on the right is a ducted unit, that would go outside your studio, not inside.

in both cases, the functionality and operation are the same. They both do the exact same thing: heat, cool, de-humidify, and move air. The ONLY difference is that the ducted unit is designed to be hooked up to ducts that take the air to and from the room, while the non-ducted unit just sucks in air at the top and spews out out the bottom. Apart from that, the do the same thing.

The humidity of the system should maintain 43 - 45%
The system should not be oversized so it short cycles, therefore not having the chance to control humidity.
The duct systems should have minimum angles and length, curving angles wherever possible.
Silencers should be on the inside of the external leaf where fresh air comes in and exhaust out (x 2 silencers) and on the outside of the internal leaf where conditioned air enters the room and stale air is removed (x 2 silencers)

More or less, yes. I normally put the silencers BETWEEN the inner and outer leaf, for maximum efficiency and maximum isolation.

The space I have between the outer face of the inner leaf ceiling and the inside face of the outer leaf ceiling is at least 300mm.

That should be enough. You could probably use ducts up to about 8" and still fit that in, but certainly 6" ducts would fit.

- Stuart -

[Purelythemusic]

in both cases, the functionality and operation are the same. They both do the exact same thing: heat, cool, de-humidify, and move air. The ONLY difference is that the ducted unit is designed to be hooked up to ducts that take the air to and from the room, while the non-ducted unit just sucks in air at the top and spews out out the bottom. Apart from that, the do the same thing.

Ah, thats helpful! So the mini split system might be all that's needed for mine as it's just one room...I notice you don't mention fresh air in or stale air out... how is best to incorporate fresh air in and stale air out...additional ducting from the in and out silencers to the room to and from the outside entry/exit silencers? But how regulated and how would an HRV be incorporated...I would assume the ducted system would be easier or more efficient at dealing with the combination system, rather than the mini split or am I over complicating it...maybe I'll park the thinking until after Easter when my friend will be giving me his advice : )

Tom

[Purelythemusic]

Another important decision to make is which will enable me to start designing the front wall, is which monitors I am going to flush mount!

I started a thread https://www.johnlsayers.com/phpBB2/view ... 12&t=21959

But it makes to collate everything here! In summary:

I have some Mackie HR824 mk1's that were used before as near field monitors but this new studio is going to command higher quality. I was going to look for a passive setup as I thought it would be better given ventilation, though still important, is less so with the passive set up...either way, back on the active speakers as they will be nicely matched in their design from the amp's to the crossovers etc.

My budget WAS around £1000-£1500 but as I see it I would be looking at the top of the 2 way monitor speakers rather than the better clarity that a good 3 way system can produce. My budget has increased magically as this is next in importance (apart from the musicians) after the room as far as I'm concerned.

I have looked at the Eve Audio range and started to look at the Adam Audio range, I'll keep looking! I've been in contact with Eve Audio about vertically mounting the SC307's and having them flush mounted as I know Stuarts had great success mounting the SC407's...but I think they are a true 3 way speaker with the mid and tweater in the middle moveable for either orientation. I think I could stretch to using the SC407's but sadly not the cut above - SC3010's I think...they look just the ticket!

I'm also seeking professional advice...about the studio...as I start swimming in this ocean, I realise how big it is and would rather have a boat...

I also have a pair of Keff 104's and a pair of Keff 105's! I know the 104's aren't as special as the 105's and they have a sentimental value so I'd like the 105's in the room but not if it's going to compromise the sound! I think the room will be tight with everything else in it!

Tom

[Purelythemusic]

I’ve been going through specs of the following which are at the top of my budgrt... qny thoughts on these:

Eve Audio sc407 I know there has been success in mounting these vertically and controls on the front!

Adam Audio A77x but I think these are more comparable to the sc307s from E.A... the Adam Audio S3V’s are just a bit pricey for me...

Neuman KH310 , not a ported speaker design which I’ve heard can improve tightness in the bass region but the guys from Eve Audio say that you can put fabric in the sc307’s and presumably the 407’s and flush mount...these Neumans are marketed as near field but I could ask if they can be flush mounted in a soffit... they have analogue crossovers whereas I believe the E.A’s and possibly A.A’s have ewer digital designs...

Focal twin 6 BE uses its 2 woofers in the same way the A.A A77x and the E.A SC307 does justwith different crossovers... I think the E.A’s crossover points are adjustable on the sc307 but I might be wrong...its late...

Wildcard - KRK Rokit 10-3 G4 - seems to be a pretty good spec but there’s something else hich feels like they’re in a lesser league than the others... I know a lot of amateurs (although I don’t know many pro’s) that use KRK nearfields... mainly for hip hop but quality accurate monitors shouldn’t be attributed to genre otherwise they may as well be hifi speakers no?

Genelec 1032c - the only 2 way... they have the SAM smart system thing...not sure...

Current favourite is the E.A sc407

[Purelythemusic]

Ok back on the HVAC track.

I now understand the systems I need a little bit more clearly.

I plan to use a mini split like the one below, which will dehumidify and cool (in that order apparently) warm air in the room and can warm the room in the winter. The AHU is in the room taking in air and putting air out. It needs an outside unit which can be up to 20m away from the AHU. This Mitsubishi unit is supposed to be super quiet in the room...21db?

Mini split unit - https://www.orionairsales.co.uk/mitsubi ... -116-p.asp

A separate unit is required to bringing fresh air in and it is wise to use an Heat Recovery Ventilation system which recovers heat/transfers heat from in to out coming in or vice versa, or an ERV which also recovers humidity. I don’t think I’ll be dealing with large variations in humidity from inside to outside air so I think I need something like this:

MHRV - https://www.amazon.co.uk/Recovery-Venti ... l_huc_item

Installed as per the previously mentioned 4 in total silencer boxes for ductwork.

The connecting bits from the mini split to the heat pump outside and the condense drain will have to go through a silenced exit hole from the studio room and a silenced hole through the outside wall presumably as we only want one penetration into the inner room would it make sense to have the electrical feed for the room come through the same silenced system? I’ll have to draw some of this up soon or it’ll be well lost in translation as I’m up to 6 silencer boxes...the last 2 being small. Condense drain can drain to a sink potentially instead of just outside...

One challenge with the MHVR is that it’s output on the lowest setting is (needs to be checked officially) 40m3/h and I believe I only need 18m3/h to introduce fresh air (and remove stale air) at 30% of the volume of the room (~60m3) each hour. I will have to do Maths as The Man Stuart has suggested I suspect.

Of course as has also been said I need to make sure the mini split is able to deal with the latent heat and sensible heat...as per another thread...I’ll update when I figure that out : )

[Purelythemusic]

Some partly nuisance news...

I’ve been waiting for the structural engineer to do all the necessary calcs and check our desing. It has taken far too long so I am working with another engineer. He is far more concerned about the proximity of the trees and the differential movement of the isolated slab amd visited today.

I now need to get a soil test done and the most likely foundation type is going to mean that the floor will have to be connected to the wall footing but this is around 800 in the ground. I really have no choice as I have a height restriction so I’ll just have to accept the sound isolation is compromised by flanking as the inner and outer leaf share the same footing essentially. Thankfully as this is below ground the earth will help to dampen. My late night drums sessions might be off the cards though!

[Purelythemusic]

Hi All,

Blimey, it's been a bit of a journey getting to the start of this. Finally a structural engineer (third and most expensive one) has given me plans and they are incorporated in the attached sketch up snap shots.

I have begun work but have been too exhausted to actually update the forum!

We have a strip footing around 1.5m down (ended up below 2m at the back wall due to bad ground). Then we have a reinforced raft foundation which is separated from the strip footing using 50mm low density EPS (Clay heave board) which is designed to take up differential movement between the foundations, but we also want it to physically separate the two.

The outer wall is 100mm dense block, 100mm cavity filled with concrete and 100mm dense block = 300mm thick retaining wall at a depth of around 1250mm which gets us out of the ground. Then the wall is carried up to the roof as a 215mm wide dense block wall.

The inner wall is a 215mm wide dense block wall built on the raft.

A concrete block and beam ceiling on the inner room walls topped with 50mm concrete as sealant and mass.

A concrete block and beam roof on the outer wall with insulation and concrete/screed top finished with a liquid rubber roof and small parapet to match the house/extension nearby.

I'll try to condense some of the pictures from the build next...an interesting journey these first 5 weeks!

[Purelythemusic]

Horaay some pictures of it in real life...not so neat.

1st big lesson was that fine soil clay reacts to water and collapses trenches. The lane at the back was built on old war rubble by the looks of it and we had a couple of big collapses at the back trench and ended up caving it in altogether and re digging.

The result of this collapse, in my design is that the strip footing sides were not neat, so they have encroached on the inner room space, quite annoying, in hindsight a few sheets of ply could have been wedged in to try to neaten up the edges of the trenches on the inside.

The next biggie was a very old pipe...brittle concrete pipe, no smell, half filled with soil...more on that...

The first bit of trench was a Friday...by the Monday we had 1m deep water...oh, ground water creeping in I thought...better plan for robust tanking plan. Thought not a lot more of it, until...

People living nearby have been convinced it was to be a swimming pool. One morning I came in to that bluey tint in the building! Water pouring in....pumped it out and checked it that evening... repeatedly. Nothing, then all of a sudden on my last check at 9pm, rushing water noise...

The old pipe was gushing water into the trench...again no smell, so relief it's not sewerage. I checked the tide times as we are next to a river...hey presto, one of the highest tides of the year! After some rigorous investigation and then called the public drains company, we worked out that the storm drain's one way valve wasn't operating at the river and we were getting a back surge...we kept and eye and have re routed the old pipe, still not in use, but hopefully no longer a problem.

The weather has been rather wet (this is England after all) so we cobbled together an evolving cover to protect the construction as best as possible!

End of last week we got the cavity retaining wall finished and concrete in the next day. Concreted the dodgy trench side and pipe re routing.

Thank goodness, we are now out of the ground, we're hoping to get a scaffold canopy at a higher level so we can work from the outside and then crack on with the inner room walls.

I found the power cable I'd previously laid, along with the ducting with rope in to pull some cat 6 and a water pipe. I've also built in a waste pipe for pumped waste from a sink...possibly a toilet, but I'm so short on space I'm not so sure.

I'll keep you guys posted!

My current decisions are around which door to use on the outer room, possibly need to get clearer on how to run the HVAC Pipework and Ventilation holes, whether to build pipe in, or build up and core out as if installing in a normal building.

My next construction challenge is getting concrete beams on the roofs...with the help of the delivery drivers who have Hi-Ab's on the delivery vehicle which could reach, but not knocking the walls!

[Purelythemusic]

Hi All,

Due to the ease of use, mainly with pictures, and also that Stuart is the main person assisting me with the build I’ve been posting all my progress on the a new forum:

http://www.digistar.cl/Forum/viewtopic. ... p=430#p430

I do hope to compile an overview of the build here as it is such an amazing resource, I’d like to contribute to it!