Garden mix room near Nottingham, UK

[garethmetcalf]

Well what a mess I made of this job!

The new 150mm external fan I bought needed me to cut away at the plastic fascia board I had installed to make the front of the building look nice. I managed to do this with my jigsaw and got a pretty good clean cut.
I then had to widen the hole that connects to the silencer, so I cut a template with jigsaw and then used the router to follow this template to cut out the hole (couldn’t get jigsaw in the gap between the joists).
I finally then fitted the replacement fan and although it did move more air it was REALLY loud. Way too loud. Annoyingly to fit it I’d drilled some new holes in the backplate so I can’t even return it. It’s now on eBay…

After that disaster I re-read Jennifer’s thread to check what fan she’d bought, an in-line fan, and set about figuring out how to mount and conceal such a fan on the outside of my building.

I finally had a eureka moment when I realised that I could get a slightly smaller fan than Jennifer’s mounted between two of the protruding joists and this would connect at a right angle to the end of the silencer box. This would entail further bodging and a massive hole saw.

I got a 150mm in line fan with specs the same as Jennifer’s (similar size room) but slightly louder (34dB or something) and it arrived this morning.

I made a mess but got it done: I had to cut away at the underside of my overhanging roof, including cutting into and removing some of the insulation (!!).

The pictures explain this way better than words. I finally switched it on and it works and is much quieter. Now to finish / cover it all up again.

Morale of the story - do proper ventilation calculations that take into account back pressure. I also could have designed this in-line fan solution from the start but the idea never occurred.

[Starlight]

I feel your disappointment, Gareth, having made plenty of mistakes myself. In time, as the studio progresses and is in use, the significance of this mess (your word, not mine) will dwindle and just be one of those little things that happened along the way.

All said, I am impressed with your design and workmanship.

[garethmetcalf]

Thanks for the kind words, Starlight.

For completeness this is the final replacement fan:

https://www.justfans.co.uk/td500-mixven ... p-202.html

I am just frustrated more than anything - I ended up wasting over £200 on a fan that is too loud, I made a mess cutting the 150mm holes as I ended up hitting a huge screw going through the roof layers into the joist, etc etc.

On the plus side, I’d saved spare bits of the cladding for the front of the building and I have some spare soffit board, so that means making good is possible.

I also had to buy another tool to cut away at the bits I needed to remove - a multi tool. £40 later and this is one of things things I wish I’d bought before… it enables cuts to happen into things at all manner of angles and positions. Super handy.
https://www.toolstation.com/bauker-300w ... ter/p54984

The downside is I’m still spending money I don’t have on this - two more fans, more tools, etc etc. But the airflow is critical to the usage of the room so I just felt this had to be done.

Final thought - I’m using the room for music and also for my home office and it’s great to be in. Here’s a shot from working on a mix at 22:30 last night - nice and cosy and no concerns about annoying neighbours!!

[endorka]

It'll be small compensation at the moment I know, but the fixing costs could have been much, much worse. Kudos for sorting it out.

What speed are you running the fan at?

Cheers,
Jennifer

[garethmetcalf]

I have the fan connected to a variable speed controller and at the lowest setting it seems ok for me on my own in the room.

However I was in there for all of today with a client and the temperature and co2 rose leading me to increase fan speed.

I feel like there is a partial blockage or something in the air system but if there is there is nothing I can do to resolve it. Either that or my expectation of what to expect co2 wise is wrong.

I think the next step is to take the co2 meter into the house and see what readings it produces as a point of comparison.

[gullfo]

you are using two fans now? one on intake and one on exhaust? if not...

[Starlight]

Source of the postif not...

... I hear that a fan (plus filter) pumping air into the room is more useful than a fan pumping air out as it creates a higher pressure in the studio and air tries to find a way out, such as when a door or window is opened, not only through the unpowered exit duct.

I know Glenn is right, though, that a two-fan system is preferable.

[gullfo]

the one fan approach really only functions in a small number of cases, e.g. a small booth exchanging air with a larger ventilated space.
whereas a forced air system is closed, so only a single (albeit large) blower for air movement, with balanced ducting and dampers, plus an outdoor ventilation (ERV/HRV) system to address fresh air requirements.

[garethmetcalf]

I only have one fan and changed it to blow rather than suck yesterday. This did seem to be better than having it extract air.

I did wonder about a two fan system. Definitely worth considering.

Thanks!
Gareth

[Soundman2020]

Source of the post I did wonder about a two fan system. Definitely worth considering.

It can work, yes. But if you go that route, it's best to get two of the same model fan if you can. One issue is to get them balanced so they are moving the same amount of air. It's not so good if you have one running at a speed that is a lot different than the other... You end up with them "fighting" each other like that. Eg, if the one blowing in is running slower than the one sucking out, then there's an "under-pressure" situation: the "sucker" fan is trying to suck out more air than the "blower" fan is pushing in, which puts an extra load on both of them. Balancing your air flows between them is a good idea, but sometimes not so easy to achieve.

I'm wondering why your static pressure is so high? Maybe you do, indeed, have a blockage? Perhaps a kinked duct someplace, or some duct liner that came loose and is restricting the airflow? Have you checked your filters? Maybe one of those is dirty and needs cleaning or replacing.

- Stuart -

[Soundman2020]

Source of the post I reckon the best solution is to have it done in hardware. Minidsp do boxes for this, and I think Stuart has recommended a Behringer FBQ unit for his final digital tuning.

Right.... sort of! The issue with the Behringer boxes is that they don't handle MIDI very well. MIDI is the only real way of sending filter adjustments to the box (unless you feel like fiddling around on the front panel, twiddling knobs and pushing buttons, to input each new filter set by hand! ( ) ). But the FBQ boxes just don't deal with MIDI well, and often end up changing filters that you did not tell them to change, while NOT changing the ones you did! It happens at random, and you often don't notice if you are concentrating on another part of the spectrum. I have a work-around for that (top secret! ) but it would be great if Behringer would get their act together and issue some type of update. This is an issue that has been known for a LONG time, and never fixed.

So yes-and-no: I like the FBQs because they have so many filters on each channel, with a good range of adjustment for the parameters, decent stability, and they work well... but I do NOT like the MIDI issue.

Right now I'm looking at other options, and one that I'm liking is the Mackie SP260. It is not really meant for this job at all, but it works very nicely for it! It's actually a speaker processors (2 in, 6 out), but does have some neat features, and it uploads filter settings through a USB connection, flawlessly. I'm working with a client right now on digital tuning for his control room, using the SP260, and here's what it is capable of. Keep in mind that this is "work in progress", nowhere near complete, and we are just doing one of the subs at present. Here's what that sub looked like a few days ago:

... and this is where we are at currently:

As you can see, that's a hell of a lot better! And all of that is just from careful tuning using the SP260. I'm impressed with how well it "just does stuff". On the down side: it is about four times the price of the FBQ...

CAVEAT! "Don't do this at home, kids!". Part of the issue with "room correction" (don't get me started....) is that you have to know what you are doing to make it work. As Jennifer pointed out, phase is a big part of the issue, and phase issues are often caused by reflections of one sort or another. You CANNOT apply a filter to a problem that is happening at the spot where there is a null from a phase problem! Doing so will not only fail to fix the problem, but will very likely make it WORSE in some way that you can't even see easily, but will definitely hear. Hence, the typical complaint you hear very often: "But I bought an expensive XYZ123 Room Correction box/software, and it made the frequency curve much flatter, yet the room still sounds like crap!". Yup. If you want to know why, don't look at the frequency response curve! Rather, look at the phase and the time-domain response. As you can see on the above graphs, all of that has been improved by careful application of the right filters in the right place... (and we are not even CLOSE to being done....)

Anyway, long rant to say: yes, digital tuning has its place, and yes the FBQ is an option, if you don't mind a lot of MIDI frustration in your life. But if you do want to go this route, beware: it ain't as easy as it looks!

- Stuart -

[gullfo]

for myself, i use the front panel settings for the FBQ. i mainly use it to simulate the Bose 901 EQ box for my Bose 901's. but as a parametric EQ, it's pretty f*ing good especially at the price point.

[garethmetcalf]

Hi
Now the weather has cooled a little in England the airflow situation seems OK - with the fan on full blowing air into the room, with just me in the room CO2 levels are staying around 650ppm when it's warm outside, and lower when cooler. No idea what I should expect, but at that I can feel a gentle airflow on my face.

I’ll leave it like this for a while and check the CO2 levels when I next get a client in and also take CO2 readings in my house for comparison. My next and final step, if needed, will be to install an identical fan on the air outlet. If I do have a blockage getting to it is near impossible as it would mean dismantling the ceiling.

I’ve checked out that Mackie box and it looks similar to the DBX Driverack my band uses sometimes… I still have a Behringer FBQ but as I now have a sub that could be integrated I can see how the Mackie could be more useful. I’m now at the point of handing over to Stuart to help with the next steps in treatment and tuning…

Still enjoying using the room, though! Those Neumann monitors sound so good in there.

Gareth

[Starlight]

Source of the postStill enjoying using the room, though! Those Neumann monitors sound so good in there.

The icing on the cake!

[garethmetcalf]

I’ve finally uploaded all my time lapse build videos. There are 6 in total each about 1-2 minutes long so they don’t really make it look as much work as it was over 6 months!

https://youtube.com/playlist?list=PLlPB ... Jq1EARiDCa

Enjoy