Is this acoustician correct?

[MJH]

Hi, 

 

We had an acoustician visit to look at treating a small ish room. It's around 9ft x 9ft. 

 

They seem good, I'm happy to go with them, but they said that "it will be hard to get frequencies below 70Hz in here."

 

Is it this simple? It's a big investment for us. I have to place a lot of trust in whoever takes on the job. 

 

I came across a discussion on stereophile.com from 2014, on bass in small rooms. One of the members, a guy called Michael Green, posted this:

 

My one listening room is 9 X 9 and easily goes into the twenties no problem.

Keep in mind sound is vibration, and if the room is not able to reproduce vibrations your not going to hear them. Also if you dampen the room to the point where you are only hearing what's coming off of the cone that's exactly what the music will sound like, "a cone" and the body of the musical notes will not be fully developed.

For many years I have had to go in and rebuild rooms that were extremely over built. It's an embarrassment for the client to spend all that money to only find that what they ended up with was frequencies and not music reproduction.

 

 

[The Computer Audiophile]

2 minutes ago, MJH said:

Hi, 

 

We had an acoustician visit to look at treating a small ish room. It's around 9ft x 9ft. 

 

They seem good, I'm happy to go with them, but they said that "it will be hard to get frequencies below 70Hz in here."

 

Is it this simple? It's a big investment for us. I have to place a lot of trust in whoever takes on the job. 

 

I came across a discussion on stereophile.com from 2014, on bass in small rooms. One of the members, a guy called Michael Green, posted this:

 

My one listening room is 9 X 9 and easily goes into the twenties no problem.

Keep in mind sound is vibration, and if the room is not able to reproduce vibrations your not going to hear them. Also if you dampen the room to the point where you are only hearing what's coming off of the cone that's exactly what the music will sound like, "a cone" and the body of the musical notes will not be fully developed.

For many years I have had to go in and rebuild rooms that were extremely over built. It's an embarrassment for the client to spend all that money to only find that what they ended up with was frequencies and not music reproduction.

 

 

 

Hi MJH, great topic and questions. All audiophiles should pay attention to this stuff. 

 

My first advice is to take it slow. When in doubt, do nothing, until you can firm up a good first step. 

 

I've gone both routes for getting better sound, acoustic treatments and digital signal processing. You can try one or the other, or both. 

 

Here is an article about my experience and a recent podcast episode where I interviewed @mitchco about his digital room correction products. 

 

 

 

 

 

[Racerxnet]

Why don't you start off with a Umic1 and REW to measure the room response and see what the results are. It's about a 100.00 dollar investment for the mic and REW is FREE. You would need both if you were going to send the measurements to someone for the correction files. Besides that, it's fun to learn. 

[ASRMichael]

With a lot of patience and careful placement acoustic panels & DSP. This has been my journey. 9x15f

 

Bottom is before & above is after. 
 

 

 

 

[March Audio]

8 hours ago, MJH said:

Hi, 

 

We had an acoustician visit to look at treating a small ish room. It's around 9ft x 9ft. 

 

They seem good, I'm happy to go with them, but they said that "it will be hard to get frequencies below 70Hz in here."

 

Is it this simple? It's a big investment for us. I have to place a lot of trust in whoever takes on the job. 

 

I came across a discussion on stereophile.com from 2014, on bass in small rooms. One of the members, a guy called Michael Green, posted this:

 

My one listening room is 9 X 9 and easily goes into the twenties no problem.

Keep in mind sound is vibration, and if the room is not able to reproduce vibrations your not going to hear them. Also if you dampen the room to the point where you are only hearing what's coming off of the cone that's exactly what the music will sound like, "a cone" and the body of the musical notes will not be fully developed.

For many years I have had to go in and rebuild rooms that were extremely over built. It's an embarrassment for the client to spend all that money to only find that what they ended up with was frequencies and not music reproduction.

 

 

 

You will get sound below 70Hz no problem.  The issue you will have is that the room modes will be quite high in frequency in small room.

 

You can download some free software called REW which can simulate the room response and take measurements if you get a microphone as @recernext mentioned above.

 

here is you room, I guessed 8ft ceiling height and speaker/listening position.

 

 

Another issue is that as your room has the same width and length dimensions those 2 room modes are at the same frequency.  So you get a big amplification at around 60Hz.  The bass will just sound boomy and one note as a result.  This is followed by a cancellation at about 80Hz.  In a simple shaped room the simulator is fairly accurate but its always best to measure to see what you really have.

 

Corner treatments can help with this, but they will ideally need to be the tuned membrane type to coincide with the room modes.  They can be quite large and impractical in a small room.  Be wary of just foam types, they wont work well as they would need to be massively deep to absorb the long wavelength.

 

Other option is of course equalisation which will notch down the offending resonances.  This can certainly work, but wont deal with the cancellations.

 

Hope that helps a bit. 

[firedog]

You can get test tones and play them back in your untreated room to see what's audible and what the rolloff of your system is.

As noted above, you are likely to have one or two significant room nodes. Acoustic treatment and DSP/EQ/DRC can take care of that. 

[GregWormald]

That would imply that headphones couldn't produce bass at all, considering that the room is only a couple of inches in all dimensions. Get a new acoustician.

[MJH]

I feel emotional reading through all this. Thank you for the kindness and patience.

 

It's a topic that can seem totally overwhelming approached online, but you have broken it down into an ethos (step by step) and some practical starting points. 

 

I will take apart this information and put it to good use. And, yes, maybe find a new acoustician, if one is needed.

 

For a few years I worked as a tutor. I was always struck by how parents trusted I was an expert, and didn't question me. I think the modern service economy has a lot of mis-information and practitioners who are not necessarily the best for the job. If it wasn't for forums like this, we could have just sunk a lot of money into something for no reason. 

[Confused]

Some good advice so far, and based on my own experience I can only agree with those that have suggested getting a Umik-1 microphone, measuring your room using REW or similar, then maybe looking a DSP etc.

 

My room is somewhat larger than 9' x 9', but with that said I am running fairly large, full range speakers.  So my room & system has it's issues, as do most rooms to be fair.

 

I would suggest that you also look at this article by @mitchco, see link below.  This covers the use of Focus Fidelity Filter Designer for providing room correction for desktop speakers.

 

Recently, I pretty much followed what Mitch had done in this article for desktop speakers, but in my case for the main system in my room.

 

I have no idea how familiar you are with "computer audio", or computer software in general.  So this stuff might look anywhere between relatively straight forward to utterly daunting and terrifying to you, I have no idea.  Anyway, here is a link to the article, well worth a read just for the quality of information provided, and I for one can vouch for the fact that this approach can lead to highly satisfactory results.

 

 

Note, I see Mitch is being referenced quite frequently in this thread, and for very good reason I would say!

[Confused]

Regarding room treatment for a smallish room, this is worth a few minutes to watch:

 

 

https://gikacoustics.co.uk/untreated-vs-treated-room/

 

 

[MarkusBarkus]

@MJHit sounds like that fella is not the right fella. A big part of this equation is your system and the layout of your room, which we (the gallery) do not know.  
 

At 9x9 you won't be too far from your speakers, right? I would really give speaker placement and seating a bounce, if you haven't already done so.

 

Like others, I would try a few treatments and gradually build the room up. I like pressure-type traps, but have velocity based as well. 
 

Of course, you really can't trap bass per se, you're just altering it's timing and behavior a wee bit.
 

Also, a sub or two, even small ones, can make a big difference, if space and budget allow. 

My room, although larger, was a real challenge. I was seated in a low-frequency null. No bass.

 

I recommended the above, as that is what I did and it worked well here. I also think the folks that recommended the usb mic and REW analysis are helpful. I need to do it myself one of these days, even though the room sounds good. Good Luck!

[MarkusBarkus]

BTW: not sure if you are a DIYer, but coincidentally, a marketing email just arrived with a discounted set of plans. I have built the Quads and mega-bass devices and they are excellent.
 

My caution would be you need some real experience or a good set of huevos to make some of these. 
 

https://www.acousticfields.com/product/all-in-one-diy-acoustic-treatment-build-plans-package/?mc_cid=3d780b7fcc&mc_eid=d729081910

 

 

[MJH]

This is all fantastic advice. A real treasure trove, enough to get going on.

 

M 

 

[Confused]

One other thing occurs to me.  GIK give free room treatment advice, see link.

 

https://gikacoustics.co.uk/acoustic-advice/

 

I have heard mixed reports as to how good this service is (mixed from very good, to not so good) but it is free, so maybe worth considering.

[mevdinc]

I have a set of big active ATCs and used them in big and small rooms with great results. Of course, small rooms have limitations but there are so many solutions and most are free and fun to experiment.
I find that speaker placement/positioning is jus as important as room treatment.
The following articles are also good place to start.
Good luck.
 

Speaker Placement Calculators:
http://noaudiophile.com/speakercalc/

Early Reflections and Bass for Small Room Acoustics:
https://www.audioholics.com/room-acoustics/small-room-acoustics
 

[MJH]

Thanks, I've spent the last couple of days going through all these leads and taking notes. 

I'll be sure to get back once things start getting somewhere. 

[MJH]

On 6/22/2021 at 8:51 PM, ASRMichael said:

With a lot of patience and careful placement acoustic panels & DSP. This has been my journey. 9x15f

 

Bottom is before & above is after. 
 

 

 

 

Would it be possible to see some pictures of your space? Or stages that you went through? 

I'm interested to see what kind of treatment you have, where it's placed etc. 

It's interesting, I've seen quite a few people start with more treatment and then slowly remove it and focus on speaker placement etc. 

[ASRMichael]

5 hours ago, MJH said:

Would it be possible to see some pictures of your space? Or stages that you went through? 

I'm interested to see what kind of treatment you have, where it's placed etc. 

It's interesting, I've seen quite a few people start with more treatment and then slowly remove it and focus on speaker placement etc. 

Hi I’ve PM’d you. 
 

I also get best speaker placement before any DSP. DSP is icing on the cake. Good Speaker placement will not only give you good imaging but will give you width & depth. All are important as each other. Fine adjustments to speaker placement will help you achieve this. 

[MJH]

Hello,

 

I posted here back in June, because some acousticians said 'you'll find it hard to get frequencies below 70Hz in this room.' 

 

Following the great feedback from this forum, I didn't follow up with the acoustician. Got a Umik instead, started measuring the room. Feels like a gauntlet has been thrown down. 

 

I wonder if anyone could be so kind as to glance over these sketches and see if they are fundamentally acceptable?

 

The tube traps would be 16 - 20" diameter, good for 40 - 55Hz. 

 

Rear wall a built in, diaphragmatic absorption panel, perhaps filled with charcoal. Maybe angled, maybe flat. 

 

Monitors built into the tubes. 

 

I can add a few more tubes, take some out, change their size. Add standard bass traps to the walls etc.  Add a subwoofer or two. 

 

At this point I'm looking at the fundamental concept, wondering what you might change. 

 

The room is not totally symmetrical. You can see from the sketches, the ceiling, a doorway, window etc. Partly why I don't want to set it up in the conventional 'face the short wall' way. 

 

I'll keep it simple for now, happy to include anything if anyone has questions. 

 

Rough footprint is 3.57m x 2.93m (11.7' x 9.6').  

[the_bat]

Correct me if I’m wrong, but by the time you put somewhere to sit in the room it looks like you’ll end up sitting around three feet from the front of the speakers. 

[The Computer Audiophile]

I must say I’ve never seen a setup like the one proposed. It seems like way too much. 

[AnotherSpin]

On 7/10/2021 at 3:23 PM, MJH said:

Hello,

 

I posted here back in June, because some acousticians said 'you'll find it hard to get frequencies below 70Hz in this room.' 

 

Following the great feedback from this forum, I didn't follow up with the acoustician. Got a Umik instead, started measuring the room. Feels like a gauntlet has been thrown down. 

 

I wonder if anyone could be so kind as to glance over these sketches and see if they are fundamentally acceptable?

 

The tube traps would be 16 - 20" diameter, good for 40 - 55Hz. 

 

Rear wall a built in, diaphragmatic absorption panel, perhaps filled with charcoal. Maybe angled, maybe flat. 

 

Monitors built into the tubes. 

 

I can add a few more tubes, take some out, change their size. Add standard bass traps to the walls etc.  Add a subwoofer or two. 

 

At this point I'm looking at the fundamental concept, wondering what you might change. 

 

The room is not totally symmetrical. You can see from the sketches, the ceiling, a doorway, window etc. Partly why I don't want to set it up in the conventional 'face the short wall' way. 

 

I'll keep it simple for now, happy to include anything if anyone has questions. 

 

Rough footprint is 3.57m x 2.93m (11.7' x 9.6').  

 

It will be interesting to see pictures of the finished project.

[MarkusBarkus]

It looks very much like some of the recording spaces depicted on various sites. Like a recoding booth, of sorts.

Caveat: I am not an acoustics person or audio engineer. 
 

I am a person who did a lot of research, thought about it, and purchased or built many treatments, which I added little by little, listening as I did so.

 

My *opinion* of the diagram is that the room would be over-damped. You do need the sound bouncing around a bit to add liveliness and life to the room. 

 

Even having a lot of room treatment (which I have) you need some differences in the sound wave paths back to your ears. Some reflections. Some diffusion. Maybe weighted to trapping low freq.

 

@MJHare we driving you crazy? 
 

If you were to add treatments a little at a time, and evaluating as you go, I would bet you would not end up at the diagram you posted above. 
 

Are all of those treatments Tube Traps? Cheers...

[MJH]

Hi,

Yes, tube traps are reflective on one half, and can be angled to maintain liveliness in the room in interesting ways. 

 

The recommended distance from Focal Be6 Solos is 3-5 feet. The sketches I've done are not exact, but they're around that range. 

 

It's not usually a good idea to sit close to the back wall, but in this room, it seems to be where the lower end works best. With the absorbers, and the right position, it should deal with the suck.

 

I agree that less is more, and that working step by step is the best approach, starting with a little bit and seeing how it works.

 

Thanks guys, 

 

Happy to hear any more thoughts / criticisms / observations.

 

 

 

 

 

[the_bat]

Also, won't you be spending pretty well as much on the various traps as you will on the speakers?