Erie Sound Studios Build (Sandledfoot returns)

[sandledfoot]

Hi All,

After the third year in my new home, I have begun construction in earnest on my 2nd gen studio in West Virginia. I have been reviewing my design and thought before I got too far along, I would go ahead and start posting I greatly appreciate all the info and time people have put into this forum. I am posting this build for others to learn. My previous studio build can be found here http://www.johnlsayers.com/phpBB2/viewt ... f=2&t=7254

Looking forward to your comments,
Cheers,
Kevin

Here are the basics of the new studio:

Studio Purpose: I am building a semi-commercial space for live instrument recording, podcasting, some videography and other related uses. Semi-commercial means I intend to register this as a business, but will not be my primary source of income. Live instrumentation means most typical rock/alt/folk band arrangements, vocals, bass, guitar (amped, acoustic), drums, etc. I intend to record musical albums, audio projects and one offs, as well as mix. I will possibly also rent space to a few fellow engineers who need studio space.

Studio Structure:

Walk out basement studio build. Approx 1200 total sqft
two walls are completely underground the other two are essentially at grade.
Cement block walls. Drylocked, 2" XPS Insulation, 2x4 stick framed interior walls, batt filled. Single 5/8th drywall for most walls.
94" ceiling height. Double 5/8 drywall

Space divided as:
2 tracking rooms
1 iso booth
1 RFZ control room
stairs/hallway/green (Will provide airlock/ separation.)
1 full bath (existing)

Upstairs (not studio space) traditionally wood framed 3bd ranch house 28x50 (1400sqft). 2x10 floor joists. Home was built 2006.
Attached 26x28 2.5 car garage


Limitations: This is in my own home and have no other residents to be concerned with. There are no building restrictions, zoning, permitting or codes to follow. (I will follow NEC). I am in a mostly rural area but neighbors are close (within 100'). The closest neighbor has a motorcycle shop, so this may pose a serious problem, but I have a good relation with him and may be able to avoid “scheduling” conflicts. It is not practical for me to isolate my rooms/house for bikes that can exceed 110db. (older bikes intentionally built loud).
The space needs to add value to my home and be convertible to useable space if the need to move/sell arises. I have read almost this entire forum and realize the limitations I am in and accept those. I am working within my budget and with what I have. If for some miraculous reason the studio project takes off and I can afford it, I will build a completely separate building elsewhere on my property later. For now, I am going to accept the limitations

I am not installing drywall to the underside of the flooring above. If needed later, I will install MLV and hardwood floors above (which will be more cost efficient and offer a greater return on investment. I am not going to use z channel. I am concerned with ceiling height and it's overall efficiency... IE it may just not be worth the cost and effort, especially since I have a single beam that I will not be able to effectively frame around for the main live room. The same approach for dual framed walls, it's just not worth losing the space, the time, effort and money (again most walls already have a block wall underground and there are complete rooms between recording spaces.

Budget: As with 99% people on this forum, I have a limited budget. I intend to pay for things out of pocket, my estimated materials costs are about 9-10k (excluding HVAC). I will do all construction, installation myself (excluding HVAC). I will have an electrician inspect all electrical work I do. I may post my budget spreadsheet at the end of the post if people will find that helpful. DM me in the meantime if you are interested in the breakdown. If you intend on contracting out the work, you will probably need to add 50-60% for markup and labor.

Electric: Main panel 200amp in garage. I am running a 60amp sub-panel to run all studio electrical outlets. All lighting and shop/bath outlets will run from circuits off the main panel. The sub panel is to facilitate ease of installation (easier to run 1 thick wire from main panel to the basement than all circuits). I also wanted easier access to a tripped breaker if the need arises. There may be additional benefits such as creating a common ground/neutral for all circuits the studio equipment will be on. I have also considered a power conditioner for this panel, but I am not certain.

Lighting - lighting is very important ! Not just for light, but for mood and impression. I have put considerable time into designing the lighting system (still not done). I intend on having three or 4 lighting systems per room.
Work - general lighting for setup/cleanup/teardown. (LED strip lights)
Task - lighting for music stands/audio console/pictures areas (Track lighting?)
Ambient - sets the mood, can provide indirect lighting (christmas lights, misc moveable pendants, etc...)
Theatrical - allows for artist specific lighting, color changing, special effects, etc... (special theatrical fixtures or FX lighting)

HVAC: I am planning on installing HVAC, but will contract this out. Depending on cost, this may or may not get done upon initial completion, I am currently getting bids and discussing system design options with contractors. I will use either an extended forced air heat pump (current system) or zoned ductless. This will depend on costs. I will post more details and decision in the thread.

Layout:

See the attached layout. (layout is from HomeDesigner). The bath / hall was completed when I moved in. The layout was somewhat predetermined due to the placement of the existing bath and HVAC/Hot water systems.



As of this post I already have everything framed except the control room. That room is going to be done last (as it currently is storing all equipment). I will need to look at the framing angles, splay walls soffit mounted etc...all of that is still in design.

Control Room - the control room is still under design, so I am very open to suggestions at this point.

Acoustic treatment: I retained a considerable amount of my absorbers from the previous studio build. I will add where necessary and build new ones, where necessary.

[sandledfoot]

Failure is always an option. This is the short, painful story of failure.

My initial plan for my studio was to acid stain the existing concrete floor. I put in some serious time/effort to clean, wash and rinse the floor (weeks worth of time). I tested an area under the stairs, and it looked good. I then applied several colors of acid stain. The floor turned out beautiful. It was exactly what I had in my mind. After neutralizing, I went to do the final rinse, i couldn't get the wash water clean. In fact, i kept noticing that the color seemed to wash off the more I rinsed an area. I took photos and sent them to the acid stain manufacturer. They said there was only one possibility, which is that there is fly ash in the concrete. I live in WV, of course there is fly ash in concrete here. I mentioned to them that there did not appear to be any written notice to not use acid stain on concrete that contains flyash. They have since added that notice to their installation guide. I am not blaming them for my lack of knowledge. This post is intended to be yet one more reminder to all of you to do your own homework before investing your money. And that even then, failure may happen. Move on.

Here is a link to the album. https://goo.gl/photos/dSqryRLYEWXbJsRK7

You'll see pictures of the second attempt to treat the floor. I had already purchased tinted sealer for use on top of the stained floor (supposed to be almost black). So the red color was supposed to somewhat lighten and contrast the dark floor underneath, which would have been the goal. Instead, I ordered an additional gallon of black tinted sealer to mix with the red color (in varying amounts to create several darker red and brown colors). Not the planned outcome, but it will serve its function.

Finally, i put down 5 coats of wax as the wear layer. I spent extra money on a satin (low gloss) wax which should have been great for the acid stain, but looks a bit muted on the more standard tinted sealer... live and learn.

[Gregwor]

It looks great now. Thanks for the heads up about concrete additives as I plan to treat my slab soonish! Thanks for the awesome update!

Greg

[sandledfoot]

Hi All,

I do intend to actually write and post photos in this forum (without links) about my build process and choices... but, I have had minimal time to put in the effort, so for now... I am going to share a link to my studio build album. Feel free to ask questions of my life...errr building choices. I post almost daily photos. Small bites of the elephant.

https://photos.app.goo.gl/TP4pAEfyoasws8Rf6

I am currently in the electrical, wiring rough in phase. My anticipated completion date will be Fall 2019. Completion in this sense means thru paint minus acoustic treatments.

Cheers,
Kevin

[sandledfoot]

In the thick of wiring, and design!

I'm working towards a soffit mounted monitor for my new control room. I currently own a pair of Event TR8s, and I really like them, but wanted to upgrade if I was going to take the time and soffit mount the monitors. I was originally thinking of Adam A77X, but I think I was talked out of that when I learned that the baffle width should be 3-5 times the width of the speaker woofer. My next choice is becoming the Adam A8X.

Here's a summary of all the best notes from a few posts about CR design and soffit monitor layout. Feel free to chime in and make suggestions or corrections.

Listen position should be between 30%-38% of room depth. (my target was 38).
Speakers should be aimed aprx 12-18" past listen position.
Max down angle of speaker should be 15d, but ideally below 7. (I am keeping it towards 7, as I want them as high as possible to get them above my desk and computer monitors.

[sandledfoot]

heres a cross section view

[sandledfoot]

I have questions...

I was under the impression that 60 gives you a wider sweet-spot (laterally) than that of 90, but your ear is more used to a direct on axis, so better to be closer to 90?

If my speaker is to be located at least 20% away from the side wall, then it seems the widest image I will be able to get in my size room is 60 degree.

Does that include the full width of the baffle? IE if the baffle is 40", does the edge of the baffle have to be 28" in? (28" is my 20% of my total room width, 120")

I believe I read that the speaker should be off of the front wall by 4"... what is the formula or standard or ... WHY? I am trying to maximize my room space and don't want the speakers into the room any more than necessary. 4" seems like a lot... what about 2" ? (just an example) The drawings show the speaker 8" off the front wall, which is close to equilateral triangle. (I know I am not beholden to that, it's as they say, just my starting point).

I have another questions I could not find a clear answer too. How do you determine the angle of the additional 'wing' baffles (circled in red)? I seem to run out of wall space.. in the overlay, my walls are in blue, and the baffle can be shown intersecting the wall directly...


how does the middle area between the baffles get filled? Hard or soft surface? It seems that there is an abundance of windows and doors typically located there. For me, I plan on mounting a large LCD/LED TV monitor, but this can change.


Do I seem to be on the right track?

PS- I hope John does not mind my using his sketch as a reference...

[Soundman2020]

Be careful with raising and tilting your speakers... Yes it is possible, if you do it with a lot of care, and carefully check your reflection angles, and figure out your comb filtering, and how you will deal with that... But not recommendable. The highest angle I've ever done is a bit less than 5°, but that was far a room considerably larger than yours...

You say:

I want them as high as possible to get them above my desk and computer monitors

Then you have the wrong layout for your desk and computer monitors!

Design your desk to be as low-profile as possible, and make sure that nothing sticks up above it very much. Then place your video screen as far forard as you can (beyond the desk, not on it), and as low down as you can while still being able to see it. If necessary, go with a bigger screen, further away, rather than a small screen up close. Keep the screen(s) well away from the direct path between speaker and ears.

Also, depending on your speakers, you can probably raise them a little WITHOUT needing to tilt anything: Check the dispersion angles and frequencies, and as long as your ears are still within the "good" section of the dispersion, no more than a couple of degrees off-axis, you'll be fine.

thinking of Adam A77X, but I think I was talked out of that when I learned that the baffle width should be 3-5 times the width of the speaker woofer. My next choice is becoming the Adam A8X.

Ummm... the woofer diameter on the A77X is 7". The woofer diameter on the A8X is 8.5", so based on that "rule", your baffle surround would have to be 4.5 inches WIDER for the A8X, than it would for the A77X...

That said, the A8X is probably he better choice for your studio. If you are considering speakers in that range, then it's worth taking a look at some of the offerings from Eve Audio: they have nice stuff too...

Listen position should be between 30%-38% of room depth. (my target was 38).

I try to keep it in the range 32% to 42% if possible. But that's just a starting point... sometimes you might need to break the rule, or bend it a little...

Speakers should be aimed aprx 12-18" past listen position.

I think you are referring to the intersection of the speaker axes behind the engineer's head? Yes, that's correct. Once again, it's just a guideline: depending on the room, you might need to have the intersection closer to your head, or further away.

I was under the impression that 60 gives you a wider sweetspot (laterally) than that of 90, but your ear is more used to a direct on axis, so better to be closer to 90?

60 and 90 what? Once again, I assume you are referring to the intersection angle behind the engineer's head? In either case, you still want your ears on-axis to the speakers, are close to on-axis. Your imaginary axis line drawn out from the acoustic center of the speaker should graze past the tip of your pinna in both cases. In your diagram, they seem to be a little too far out.

I believe I read that the speaker should be off of the front wall by 4"...

That only applies to speakers set up on stands in the room: it does not apply to soffit-mounted speakers.

what is the formula or standard or ... WHY?

It's all about baffle step response and SBIR from the front wall. Basically, your speaker emits low frequency sound in all directions, not just heading towards your head. The sound radiated "backwards" (behind the speaker, going towards the front wall of the room) hits the wall and bounces back, then interferes with itself causing phase cancellation at the mix position. The frequency where that happens depends only on the distance between the speaker and the wall. If the distance is between about one foot and four feet, then that produces a very deep "dip" in the low frequency response as heard at the mix position. THis is called "SBIR", for "Speaker-Boundary Interference Response" That's why, for people who are NOT going to have their speakers in soffits, the only solution for a small room is to push the speaker up tight against the from wall. That forces the SBIR dip up higher in frequency, out to the low end where it can't be treated and is very noticeable, into the low mid range, where it is less noticeable and where it CAN be treated... But you also need acoustic treatment between the speaker and the wall, and that will be about 4" thick, thus, you need to leave a 4" gap for that.

But none of the above applies to you, since you are planning to soffit-mount your speakers, so there won't be any SBIR from the front wall. That's one of the major reasons for soffit-mounting: it eliminates front-wall SBIR.

However, you WILL still need some space behind your speaker! It needs ventilation up the back to keep it cool, and there are other reasons why it should not be directly against the wall, so you still need to leave a good gap there.

I am trying to maximize my room space and don't want the speakers into the room any more than necessary.

Then don't tilt them down! That wastes space... If you leave them vertical, with no tilt, then they can be closer to the front wall...

Also, offsetting the speakers on the baffle face outwards, instead of inwards, can gain you a little extra space.

how does the middle area betweetn the baffles get filled? Hard or soft surface? It seems that there is an abunduance of windows and doors typically located there.

It could be hard, or it could be soft, depending on what the room needs. I normally do REW tests at many points during the construction of the room, then decide on the front wall treatment based on that, when the time comes.

- Stuart -

[sandledfoot]

Stuart,

As always, you give me (and others) so much help, thanks! I understand through your posts that there doesn't seem to be a hard and fast rule, but a series of guidelines to be used to accomodate your exact situation. I've been trying to design with that in mind.

The Adam A77X was the dual 7" monitors, so I was kinda assuming it acted somewhat close to 14" woofer... but I'm glad your OK with the A8X, they're a bit cheaper. I have looked at some of the Eve and Barefoot monitors as well, just depends on pricing I guess.

As for the tilt, I definitely will consider re-positioning the video monitors, and my desk is 31" high from the ground, so fairly standard. I wouldn't want something much lower because I wouldn't be able to sit under it... it definitely comes an ergonomics issue at that point. I should mention, that the bottom of the speaker as shown is only 4'2" above floor height. (In my first post, i mentioned my total ceiling height was only 95".

I'm still unsure of the side walls and angles coming off of the baffle. Any ideas for that? Is that just angled to prevent parallel walls to avoid slap echo? I also understand its supposed to be angled to direct reflections behind the mix position, but how is that determined? I can dray a line, but sound moves as a wave and it's hard for me to visualize the geometry.

Thanks again, your advice is much appreciated!
Kevin

[Soundman2020]

As for the tilt, I definitely will consider re-positioning the video monitors, and my desk is 31" high from the ground,

That's a little high, actually. "Standard" desk height is 29" (depending on who you believe...), and most desks are 28" to 30". Studio desks are generally a bit lower, since you normally have a console sitting on it: I often use 26 1/2 to 27" for my studio desk designs. That still gives you enough knee-room.

I wouldn't want something much lower because I wouldn't be able to sit under it... it definitely comes an ergonomics issue at that point.

Try it! With a 27" desk made with a 1" top, you should still have at least 2" between the bottom surface and your legs. That assumes you have your chair set to get your ears at the correct listening height.

I should mention, that the bottom of the speaker as shown is only 4'2" above floor height.

The height of the bottom, top, or center of yoru speaker is irrelevant... What matters is the height of the acoustic axis. That's the point from which the sound seems to emanate, and is the key reference point for all measurements related to the speaker. The standard height for the acoustic axis is 120cm above the floor, which is 47 1/4". Depending on your speaker and room, you can normally go a litter higher than that. The objective is to have the acoustic axis of the speaker at the same height as your ears, or a little higher. Everything else in the room should be designed around that. The speakers are the very reason why the room exists at all, so the room should be designed around the speakers.

i mentioned my total ceiling height was only 95".

You might want to consider flipping your speakers "upside down", with the woofer above the tweeter. That can sometimes help to get the woofer away from the modal nulls that happen at 50% of room height. Or you might WANT to have your speaker in the modal null, if you are expecting modal issues at problematic frequencies.

I'm still unsure of the side walls and angles coming off of the baffle. Any ideas for that? Is that just angled to prevent parallel walls to avoid slap echo? I also understand its supposed to be angled to direct reflections behind the mix position, but how is that determined? I can dray a line, but sound moves as a wave and it's hard for me to visualize the geometry.

The entire concept behind RFZ design is that all of the surfaces at the front of the room are angled to redirect first-order reflections away from the mix position, leaving an "empty" region around the engineer's head where there are no reflections at all.

For high frequencies, sound behaves mostly like rays of light: for low frequencies, it behaves more like a balloon inflating. For intermediate frequencies, it behaves somewhere in between... sort of like an expanding cone. So, by carefully looking at the dispersion characteristics of your speaker, you can figure out what frequency range will be heading out at which angle, then based on that, figure out how it will reflect.

Having said that, you can get a pretty good idea from the "ray tracing" method. I have created a "ray-trace rainbow" in Sketchup, which I use when I'm designing studios. Here's an early version of that:

Soundman2020-Ray-Trace-method-01.jpg

I've since developed that into a more sophisticated template that I can just attach to any speaker.

You use that by just seeing where the sound is going, and what angles it is hitting your surfaces at. You can then draw a line out from that surface, perpendicular to it, at any interesting point, see what angle the sound is ARRIVING at that point, then draw another line out from the same point, mirror-imaged, so it leaves at the same-but-opposite angle. You then assume a similar "rainbow" leaves that point, but you take into account the frequencies. For example, if you are looking at a ray that originated 60° off-axis from the speaker, then there won't be too much high-frequency content in that, so you'd be looking mostly at how mids would be reflect off that surface. Then you adjust the angles of the surfaces as needed, to ensure that you don't get any specular reflections at the mix position, or within a sphere around it.

- Stuart -

[sandledfoot]

Stu,

I will take a close look tonight to see what the angles line up to be for first reflections. I think that was the key part I didn't udnerstand, so that helps. As for desk height, I am leary on changing the total height of the desk, but... it is on casters and if I take the casters off, then it would lower the desk by 2-3"... i'll have to look when I get home to be sure. My side car desk is at 26" so the faders are at wrist level. I built both of these desks a few years ago in my previous studio location and designed them to be taken with me. it would be a shame if I have to build new ones!

I see what your getting at with the speaker height, so I will revisit the angles. I am concerned that the 3/5 placement within the baffle is going to give me a problem (as it seems to run into the wall), so I am not sure how to get a 60d splay, keep the baffle width at 40" (for 8"woofer) and then add a wing wall to reflect sound away from the mix position. but, i'm sure it can be done!

Thanks for your time again,
Kevin

[sandledfoot]

So before I continue down this path of control room design... i've had a thought and I'd like some opinions.

I currently mix on Event TR8s and I like them. I am considering new Adam A8X monitors to soffit mount (as mentioned above), but I am concerned that the Adam A8X will not be that much of a departure from the current TR8, (not withstanding better top end). Specifically, I am looking for something that can be louder when needed. I don't mix at high volumes, but do push it when listening to the kick, bass and a few times before running my finals. That being said, I am starting to look at some higher wattage monitors. The Adam S2V and S3V seem like a good fit, but this is probably going to be beyond my price range... maybe. If this is an investment that I can use for 10years +, then I'll consider it.

for context, price listed per pair for readers perspective:
Adam A7X ($1,500)
Adam A8X ($2,000)
Adam S2V ($3,000)
Adam S3V ($5,000)
Eve Sc307 ($2,890)
Eve SC407 ($5,700)
Neumann HK310 ($3600)

Again, I really only want to design this control room once, and as Stu has reminded me, choose the speaker then design around that.

My question is this...

What would be an appropriate size/wattage for the control room of my size (12x18). Is there a target SPL that you aim for?

been following a few other threads here...
https://www.johnlsayers.com/phpBB2/view ... 2&start=30

[Soundman2020]

I am concerned that the Adam A8X will not be that much of a departure from the current TR8, (not withstanding better top end). Specifically, I am looking for something that can be louder when needed.

I'm not sure I follow you here: How much louder than 120 decibels do you need? That's already ear-damaging territory... If you are playing that loud, then I sure do hope you are wearing hearing protection... 120 dB is the threshold of pain, according to some sources (others say 125...). That's insanely loud for a control room. Most engineers mix at around 80 dB, and push it to 90 or maybe 100 to "check the bass", but pushing it to 120 is not a good idea at all. Why would you need more than that? I must be missing something here...

The Adam S2V and S3V seem like a good fit,

... and they both put out the exact same maximum sound level as the A8X... Actually, the S3V can go 4 dB louder, but I really doubt you'd be able to hear the difference between 120 dB and 124 dB.... because you'd already be deaf after listening to the 120, so you'd never even hear the 124 at all!

You also have the SC407 on your list, which puts out 1 dB LESS than the A8X, so if you are looking for higher maximum sound level, then the SC307 and SC407 are not it. But if you are looking for fantastic quality, then either of those is a great speaker, as is the A8X. Here's a room I did with a pair of SC407s a while back: http://www.johnlsayers.com/phpBB2/viewt ... =2&t=20471 That's a fairly large room, and there's way more than enough "oomph" in those guys to more than fill the room.

There's a typo in the last one on your list: It's the KH301, not the HK310. It's also a fine speaker, but it puts out the lowest sound level of all of them, at only about 110 dB. Still fine for the majority of rooms.

What would be an appropriate size/wattage for the control room of my size (12x18)

Wattage is irrelevant. Wattage only tells you how much power the amp can produce without clipping. What matters is how much sound you get out of the speaker, for that amount of wattage. That depends on the efficiency of the driver design: higher efficiency drivers can produce more sound from the same number of watts, so looking at the wattage isn't very useful. Especially when you start to see that some manufacturers play games with the power ratings in watts, and quote peak figures, instead of RMS. It's been a while since I last saw it, but a few years ago there was a fad among some manufacturers of really lousy, low quality speakers to quote the power rating in the fictitious units of "Watts PMPO", meaning "Peak Music Power Output"... which basically meant how much power could the driver absorb before it fried in a large puff of smoke, when you pumped in stupidly huge amounts of power for a tiny fraction of a millisecond....

For studio monitors, forget watts: look at the actual sound pressure level that the speakers can produce. Your ears hear decibels, not watts.

(OK, before some pedantic purist comes along and says that I'm wrong, and you DO hear watts, let me clarify: you hear acoustic watts, not electrical watts. Power amplifiers put out electrical watts, which the driver turns into acoustic watts. And the number of acoustic watts you get depends, once again, on the efficiency of the driver. A typical speaker pushed to its peakwill only put out about one watt of acoustic power, probably less... when you consider that the amp is producing many hundreds of electrical watts to achieve one acoustic watt, you realize just how inefficient drivers really are... And to put all that in perspective, a full symphony orchestra puts out about one watt of acoustic power).

Hope I didn't confuse you too much!

- Stuart -

[sandledfoot]

Stuart,

I understand, and I agree, I am not planning on mixing at over 90db very often, and then in short increments to check something specific or the final mix. I am also at the limits of my knowledge in terms of understanding how speaker efficiency and wattage convert to db, but I do understand that as a general rule, the more watts available from the amplifier, the cleaner the speaker can deliver audio (in addition to being louder). That is what I am after, in terms of being able to have something that is capable of delivering very clean audio, at high volumes, without stressing the amplifier, speaker or sacrificing quality. I mean, there is a reason the S series costs more and has more watts than the AX series, right?

I have a good bit of experience with live sound, so i'm familiar with keeping tabs on db and and understand the basics of sound reinforcement, i'm just trying to apply that to the control room environment.

Its good to hear the A8X is something your still encouraging... it's definitely more affordable than the other options. I am going to see if I can do a bit more homework, look at your thread and go from there.

As always, I appreciate your input.

Kevin

[sandledfoot]

Short update.

I am 95% through framing. The remaining 5% is the soffit to hide the HVAC ducting. I am currently working on the HVAC, specifically the HRV system ducts. I am almost done with those runs. I have posted photos throughout, including the labyrinth box (duct silencer) to my google photos drive, shared at the beginning of this thread. I will eventually go back and annotate and post photos here for posterity, but I have not had a chance to do that... and google photos now uses the HEIC extension that apple uses which is not compatible with this site.