need some clarification here . .

[rush1974]

hi guys and sorry for all these post . . just a few things that are confusing me . i managed to find some pic from the forums and i'll put them up so that you guys can see what i'm trying to ask . again these are not my pic and i'm just trying to understand the terms and some clarification .

pic # 1 :
do you call this foam or insulation . i guess this goes behind the drywall in between the joists . and can this be used for making your own bass traps . meaning build a frame and put this foam or insulation inside and cover up with fabric . i'm not sure what this 703 looks like or is this 703 but the itchy stuff that you get from your local home depot store which you put in between your joists, can you put that insulation into a frame and make up your own bass traps or sound absorbers . .

pic #2 :
What exactly do you call this . sound absorbers or diffusors or foam or ?? and do you have to put a lot of these on your walls . (BTW all this info i need is for my control room that i'm trying to build size 13' x 9' with 7' celing)

pic #3:
i see some guys are building their monitors inside a wall as you can see one person was doing in his/her studio while others are not putting their monitors inside a wall but ontop of a desk or stand with sound absorbers or foam around that area as you can see in pic #4 .
what is the advantage or disadvantage or is it better to build a new wall and place the monitors inside there. and in pic #3 when this person's studio was finished i didn't see any of those foam (in pic#2) anywhere on the walls .

also in pic #3, where the monitors are placed inside a wall what kind of stuff is behind the wall . I mean is it hollow or open in there or that behind is stuff with insulation or foam or ???

pic #4:
as mentioned above, is it a good idea to go like pic #3 and have your monitors in the control room insde the wall or like pic#4 on top of a desk with absorbers hanging or foam . .

sorry guys if i put up your pics without asking but i though this would be a better way for me to ask quesitons and understand a lot of this . looking at your pics make things clear to me and helps me understanding too . .

thanks

 

[NL5]

Pic #3 turned out to be a mistake......I wouldn't soffit mount nearfields.

 

[NL5]

Pic #1 is 703

 

[BillyBo]

pic 1 definitely looks like 703. it's not pink and fluffy like the fiberglass you DONT want to be using for making acoustic panels (see my thread "my latest project - 703 panels")

pic 2 is Auralex foam. it's the "good" foam. maybe the only foam i'd suggest getting if you were to go that route. it's not quite as good (so i've heard) as 703/705 panels, but works.

pic 3 is something i wouldn't get into anyway unless you were certain you knew what you were doing. NL5 says it was a mistake anyhow.

 

[NL5]

I'd go over to John Sayers and get some advice.....

 

[Ethan Winer]

Mounting speakers flush in a wall solves a certain type of low frequency problem called SBIR - Speaker / Boundary Interference Response. This is a series of peaks and deep nulls whose frequencies are related to the distance between the speakers and each nearby room boundary. But it's not practical for most people to do this, and as NL5 said some near-fields should not be in a wall. However, this does not apply to all near-fields. Only those with a rear port.

--Ethan

 

[NL5]

Mounting speakers flush in a wall solves a certain type of low frequency problem called SBIR - Speaker / Boundary Interference Response. This is a series of peaks and deep nulls whose frequencies are related to the distance between the speakers and each nearby room boundary. But it's not practical for most people to do this, and as NL5 said some near-fields should not be in a wall. However, this does not apply to all near-fields. Only those with a rear port.

--Ethan

Ethan -

Maybe you can clear this up - I'll try and find the post I was sent to when the issue came up. It was by Thomas Barefoot - and he pretty much claimed that no nearfiled was designed for soffit mounting. Even though in the past even he recommended they be soffit mounted.
It seemed to match my experience. I am by no means an acoustics expert though, so I would like to hear your thoughts.


here is the post -

http://www.gearslutz.com/board/so-m...monitors-soffit-mounted-5-1-a.html#post609093

 

[rush1974]

Pic #3 turned out to be a mistake......I wouldn't soffit mount nearfields.

ok now I gues the terms sorted out but still a bit confused . . . .

does soffit mean monitors build inside a wall or ? ? Also how can you tell if your monitors are nearfields or ?? I have the Events 20/20 5" monitors.

However, this does not apply to all near-fields. Only those with a rear port.

--Ethan

Ethan, what exactly is a monitor with a rear port . . .

BillyBo
pic 1 definitely looks like 703. it's not pink and fluffy like the fiberglass you DONT want to be using for making acoustic panels (see my thread "my latest project - 703 panels")

pic 2 is Auralex foam. it's the "good" foam. maybe the only foam i'd suggest getting if you were to go that route. it's not quite as good (so i've heard) as 703/705 panels, but works.

pic 3 is something i wouldn't get into anyway unless you were certain you knew what you were doing. NL5 says it was a mistake anyhow.

ok . . . Now where exactly can I find this 703 in Toronto.
and you mentioned better to get the Auralex foam. Well, that I know I can get it from LongAndMcquade . Now if I do get the auralex foam do I also need the 703 or either one . .
Now if I'm going to get the auralex foam that mean I can leave my monitors on top of my desk and place the foam behind or whereever needed including bass traps . correct . . . I guess then I don't need to do that in wall monitor setup and construct a wall with the monitor inside the frame. . I can just go buy the auralex foams and place them as needed . .

and lastly, is a tracking/control room 13'x9' with 7' celing enough or the space is too small . . it would be nice if someone in Toronto knows places where to buy these from instead of ordering them online . .

thanks guys for all the tips and sugestions . . I will check out John Sayers site and read up more there too . .

 

[gullfo]

i think that Thomas was making the point that most speakers are designed to operate in free space (technically 4pi but in most cases really 2pi or pi) and that soffit mounting can exaggerate the response (and Thomas has been great in helping people sort through cross over issues for years now) and that speakers not designed (or probably more correctly tested) for soffit mounting could result in worse translation instead of better...

rear port (meaning the bass port or opening on many speakers is in the back instead of the front) speakers can be soffit mounted but you need to leave enough space or opening to ensure they vent correctly. this is important for response as well as heat removal (and even more important on self-powered speakers). as a general rule, check with the manufacturer as to whether or not you could soffit mount them, determine what benefit you are seeking from soffit mounting (room response, floor space vs stands, etc), and determine what you might need to do for baffle step compensation (crossover, speaker circuit adjustments, etc) before going through the trouble.

in most cases small speakers can be soffit mounted but typically 8" or larger are a better choice. chances are good you'll still want nearfields (on stands of course ;-) to ensure you can check your mixes on at least a couple of pairs (and preferably even a single mono speaker) of speakers.

 

[Ethan Winer]

Thomas Barefoot - and he pretty much claimed that no nearfiled was designed for soffit mounting.

The main point in Thomas' explanation is:

Freestanding speakers more accurately represent real world playback and, therefore, translate much better.

I disagree with that. By that logic we should all mix in untreated rooms using random hi-fi speakers because that's what most people have. The following quote is from my Acoustics FAQ, and it explains why I believe the goal for mix rooms must be accuracy, not being typical. Especially since "typical" is all over the map.

--Ethan

You may ask why you need acoustic treatment at all, since few people listening to your music will be in a room that is acoustically treated. The reason is simple: All rooms sound differently, both in their amount of liveness and their frequency response. If you create a mix that sounds good in your room, which has its own particular frequency response, it is likely to sound very different in other rooms. For example, if your room has a severe lack of deep bass, your mixes will probably contain too much bass as you incorrectly compensate based on what you are hearing. And if someone else plays your music in a room that has too much deep bass, the error will be exaggerated, and they will hear way too much deep bass. Therefore, the only practical solution is to make your room as accurate as possible so any variation others experience is due solely to the response of their room.

 

[Ethan Winer]

Ethan, what exactly is a monitor with a rear port

A Mackie HR824 has a bass port in the rear. Since some sound comes out the rear, and is part of the speaker's operation, putting an 824 inside a wall will prevent that sound from getting into the room as intended by the speaker designers.

--Ethan

 

[NL5]

Ethan -

In all fairness, I think you are oversimplifying his response. He said -

"This radiation misbalance creates a -6dB low-end shelf in the direct field response. But we know that the direct field response is very important and needs to be flat. The solution is to build a compensating -6dB high shelf filter into the crossover. This flattens out the direct field response, but now the power response has a -6dB high shelf. In a soffit mount situation the front of the speaker and the wall act as one very large reflector that forces all the of the sound into the forward hemisphere, from the high frequencies down to the low. So there's no -6dB low-end step in the direct field response, and no need for a -6dB high shelf filter. In other words, when the power response is flat, so is the direct field response.

Great, then soffit mounting is better, right? Well, in theory yes. But you have to consider what most people in the real world are listening to. They have freestanding speakers not soffit mounts. Likewise, car audio designers typically try to mimic the -6dB high shelf power response of freestanding speakers. In the real world freestanding is the norm. In the real world speakers output +6dB more bass energy than the highs. And you can't get this effect with soffit mounted speakers without adversely altering the direct field response as well.

Recording engineers who try to work with soffit mounted speakers often find that their mixes translate as overly dark on other system. This makes perfectly good sense because they are working on speakers with a flat power response."


Now, I have no idea which is actually better. In my own experience, what Thomas said seems to have applied. I have a JLS "inspired" CR design, and tried to follow the correct procedure for soffit mounting. Could it be poor implementation on my part - very well could be, I've only built one CR.

I also don't think flatness is the ultimate goal - translation is. Now, the two go hand in hand more or less, which brings me back to the original question. Is it better or not?

Yes, I am totally confused. Acoustics is BY FAR the most confusing part of recording.

 

[gullfo]

it is complex... in most of my designs, i include the option to build in a soffit (baffle) mount, but i generally prefer monitors on stands behind the console because it's more flexible in terms of angles and spacing and less prone to construction errors. that said, just sticking monitors on stands is not going to guarantee success unless the room has the right acoustics so even if you don't go through the trouble to create a baffle mount system, doesn't give you a free pass when you put your monitors on stands...

 

[Ethan Winer]

The solution is to build a compensating -6dB high shelf filter into the crossover. This flattens out the direct field response, but now the power response has a -6dB high shelf.

Okay, but don't most (all?) powered near-field speakers have low-cut switches that you can use or not use?

In the larger picture, it seems to me that near and far are more about the size of the speaker than anything else. But I admit I'm not a speaker expert. Maybe you can invite Thomas here to add his two cents?

--Ethan

 

[RICK FITZPATRICK]

As to the "soffit mounting" of ported speakers. Well, here was my solution. I simply blocked off the port in my CONSUMER speakers and beefed up the case, decoupled the support mechanism, and let it be! Sounds terrific. Although, untill I can afford REAL studio monitors that CAN be soffit mounted, this will have to do. I do have small studio nearfields on my console bridge. Mostly, I use my soffit mounted speakers to LISTEN TO MUSIC!! It sounds better than on my near fields.

https://homerecording.com/bbs/showthread.php?t=255023&highlight=Soffit
fitZ

 

[barefoot]

i think that Thomas was making the point that most speakers are designed to operate in free space (technically 4pi but in most cases really 2pi or pi) and that soffit mounting can exaggerate the response (and Thomas has been great in helping people sort through cross over issues for years now) and that speakers not designed (or probably more correctly tested) for soffit mounting could result in worse translation instead of better....

Yes. A freestanding speaker has what is called a "baffle step" or "diffraction loss". The high frequencies radiate only into the forward hemisphere because the wavelengths are small compared to the front of the speaker cabinet (the baffle), while the low frequencies radiate omni-directionally because the wavelengths are large compared to the baffle. In order to achieve a flat on-axis response (critical for various reasons) a freestanding speaker must have a -6dB high frequency shelf filter, usually designed into the crossover. In others words, freestanding speakers radiate 6dB more low frequency energy into the room than they do high frequency energy. Since we don't live and work in anechoic chambers this creates a very particular translation character: flat on-axis direct (early) response and a +6dB low shelf ambient response.

Soffited speakers have both a flat on-axis response and a flat ambient response (for simplicity we'll leave out many details about speaker directivity.) This would seem great, but 99.9% of the consumer world listens to freestanding speakers, or car stereos that try to mimic the response of freestanding speakers. You could try to mimic the +6dB low shelf ambient response of a freestanding speaker by making the room more absorptive in the highs and less absorptive in the lows, but you run into another disadvantage of soffit mounting. Mounting speakers in the walls puts them in the optimal place for driving room modes. So low frequency absorption becomes even more critical. Then, if you use lots of low frequency absorption and lots more high frequency absorption, the room become far too dead and the system doesn't translate well once again.

Freestanding speakers do have issues with early reflections, but these can be mitigated using judiciously placed absorbers and diffusers. Of course they're not ideal, but in general freestanding speakers present fewer problems and translate much better than soffited speakers

I disagree with that. By that logic we should all mix in untreated rooms using random hi-fi speakers because that's what most people have. The following quote is from my Acoustics FAQ, and it explains why I believe the goal for mix rooms must be accuracy, not being typical. Especially since "typical" is all over the map.

No, this logic doesn't hold. My point is that soffited speakers are a completely different species with respect their power response and therefore don't translate well; with a few notable exceptions. Good translation is a complex problem. In most aspects it does call for "accuracy" beyond that of average consumer speakers. However, in a few critical aspects it calls for very "middle of the road" characteristics. And power response happens to be one of the things that works best when it's middle of the road.

You may still disagree, but my perspective is also confirmed by the vast majority of recording engineers I've spoken to. I used to be a proponent of soffit mounting and couldn't understand why they all just "didn't get it." Then I finally started to actually listen to what they were saying. Most engineers will tell you that soffited speakers translate into very dark sounding recordings. And if you want your record to sound balanced, you need to make it sound uncomfortably bright on the soffited speakers. Now if you think about it for a minute you'll realize this jives exactly with what I wrote above about the differences in power response (ambient response) between freestanding and soffited.

Taking it a step further, you might ask what are the exceptions? Well, the soffited speakers that engineers often report as translating well are almost invariably horn-loaded types. And once again, this makes perfect sense in the context of my power response argument. A high frequency horn driver radiating into approximately quarter-space crossed over to a low frequency driver radiating into half-space and EQ'd for a flat on-axis response will yield the same kind of +6dB low shelf power response as a freestanding speaker. That pretty much seals the case as far as I'm concerned.

Thomas

 

[NL5]

You may still disagree, but my perspective is also confirmed by the vast majority of recording engineers I've spoken to. I used to be a proponent of soffit mounting and couldn't understand why they all just "didn't get it." Then I finally started to actually listen to what they were saying. Most engineers will tell you that soffited speakers translate into very dark sounding recordings. And if you want your record to sound balanced, you need to make it sound uncomfortably bright on the soffited speakers. Now if you think about it for a minute you'll realize this jives exactly with what I wrote above about the differences in power response (ambient response) between freestanding and soffited.

This is exactly what I was referring to in the beginning. It pretty well sums up my experience exactly.

Thanks Thomas!

 

[barefoot]

Ethan -

In all fairness, I think you are oversimplifying his response. He said -

"This radiation misbalance creates a -6dB low-end shelf in the direct field response. But we know that the direct field response is very important and needs to be flat. The solution is to build a compensating -6dB high shelf filter into the crossover. This flattens out the direct field response, but now the power response has a -6dB high shelf. In a soffit mount situation the front of the speaker and the wall act as one very large reflector that forces all the of the sound into the forward hemisphere, from the high frequencies down to the low. So there's no -6dB low-end step in the direct field response, and no need for a -6dB high shelf filter. In other words, when the power response is flat, so is the direct field response.

Great, then soffit mounting is better, right? Well, in theory yes. But you have to consider what most people in the real world are listening to. They have freestanding speakers not soffit mounts. Likewise, car audio designers typically try to mimic the -6dB high shelf power response of freestanding speakers. In the real world freestanding is the norm. In the real world speakers output +6dB more bass energy than the highs. And you can't get this effect with soffit mounted speakers without adversely altering the direct field response as well.

Recording engineers who try to work with soffit mounted speakers often find that their mixes translate as overly dark on other system. This makes perfectly good sense because they are working on speakers with a flat power response."

Ah, you already quoted me. I could save myself some effort if I would just read the whole thread!

Thanks!

 

[RICK FITZPATRICK]

Likewise, car audio designers typically try to mimic the -6dB high shelf power response of freestanding speakers.

Car speakers are ALL soffet mounts. Show me a free standing CAR speaker. Could you please explain how they "mimic the -6dB high shelf power response of freestanding speakers"? And why? Soffet mount speakers sound BETTER toi me than free standing. So why mimic "free standing" speakers in a LISTENING environment rather than a monitoring environment that needs to MIMIC the "typical" listening environment?

 

[pandamonk]

Car speakers are ALL soffet mounts. Show me a free standing CAR speaker. Could you please explain how they "mimic the -6dB high shelf power response of freestanding speakers"? And why? Soffet mount speakers sound BETTER toi me than free standing. So why mimic "free standing" speakers in a LISTENING environment rather than a monitoring environment that needs to MIMIC the "typical" listening environment?

Sorry to jump in, but he said car speakers mimic free standing, they aren't actually free standing.

I think the point is that they may sound better, but they don't translate better.

Free standing has high freq -6dB filter to compensate for the omnidirectionality and achieve a flat on-axis early response. This leaves a +6dB low freq ambient response that you don't get with soffit mounts.

So when you mix, you compensate for this and it translates "dark".

That's what I've taken from what he said.

The way i can think to mimic it, in a car/soffit, is to add slight reverb/ambience with a HF -6dB filter, or just have a slight HF filter on the whole track.

But surely you want to mix in a flat environment so it translates well on every system. Yeah it might translate "dark" on a freestanding system, but if you compensate for this, it might translate "bright" on headphones etc.