To Soffit mount, or not?

[cborg]

I've got a couple of wonderings:
How do you select the position of the monitors that you will soffit/flush mount regarding to the room/shape?
Mathematical only or by measurement as well?
And in the case of measurement: How do one evaluate the measurement with regards to adding a angled wall partition in which to create the soffit/flush mount?

[Jeffrey Hedback]

Hello cborg,

Great questions and here are some of my thoughts on the topic.

You have to position the monitors based on the horizontal character of the speaker. What is the on-axis response, 15deg hor, 30deg hor and even out to 45deg horizontal??? This is primarily above ~1K. So you can (if the manufacturer doesn't supply trust worthy data), place your speaker in a dry environment above this region and do tests at 1 meter and 2 meters. Doing vertical studies on axis, 15deg and 30deg can help at times.

With that data, create 60 degree spread between (30 deg each side from center axis) so that the speakers triangulate ~18"-32" behind the desired mix location. I use BEM studies to see where the likely mix position is going to be best positioned (this way I can factor the non-rectangular geometry). The range of ~18"-32" would be determined by the the horizontal directivity data. If your speaker is a CD type (controlled directivity...er, compressions driver/horn), those can be flat off-axis out to 60deg or more which can open up even wider distances between L & R spkrs.

[audiothings]

Hi ake . Room is 10.6W x 18L x 7.6 ft H.

Radial, I didn't get past that post... I know this thread is long and you may have sorted your scene out, but I had ten minutes to kill and I asked myself what I could come up with... BTW, I usually think NE and not RFZ, and the 10" of absorption around the room, in my idea, would comprise of metal panel absorbers, with a facade of 4" of 705.



and another

[pitchfork]

whoa. slow down.

He was addressing Opus of Trolls and his suggestion of changing to pressure absorbers..... Andre was simply expressing that Opus could have no idea what you were actually doing based on the information he had at hand.

My apology if that is not the case.

Just for starters he could be using Invisible Alpha© absorption in that part of the room.

I don't know bout you John, but I'm inclined to take things at face value, and in this case, to me, it was blindingly obvious, based on past interactions. But I never claimed to be an expert in decoding subtle humor, vs your expertise. Should that be the case, then by all means..the laughs on me.

[kasmira]

Originally Posted by pitchfork

I don't know bout you John, but I'm inclined to take things at face value, and in this case, to me, it was blindingly obvious, based on past interactions. But I never claimed to be an expert in decoding subtle humor, vs your expertise. Should that be the case, then by all means..the laughs on me.

You realize that Invisible Alpha is a fun term Andre coined to explain hidden absorption, right? It is not a commercial product. It is not for sale.

[cborg]

Originally Posted by Jeffrey Hedback

Hello cborg,

Great questions and here are some of my thoughts on the topic.

You have to position the monitors based on the horizontal character of the speaker. What is the on-axis response, 15deg hor, 30deg hor and even out to 45deg horizontal??? This is primarily above ~1K. So you can (if the manufacturer doesn't supply trust worthy data), place your speaker in a dry environment above this region and do tests at 1 meter and 2 meters. Doing vertical studies on axis, 15deg and 30deg can help at times.

With that data, create 60 degree spread between (30 deg each side from center axis) so that the speakers triangulate ~18"-32" behind the desired mix location. I use BEM studies to see where the likely mix position is going to be best positioned (this way I can factor the non-rectangular geometry). The range of ~18"-32" would be determined by the the horizontal directivity data. If your speaker is a CD type (controlled directivity...er, compressions driver/horn), those can be flat off-axis out to 60deg or more which can open up even wider distances between L & R spkrs.

Many thanks for sharing Jeff!
So with sufficient data on the speakers selecting positions is done primarily by modeling the response.
Interesting to see you mentioning above 1k as well , because that's my (much more limited) experience too.

[pitchfork]

You realize that Invisible Alpha is a fun term Andre coined to explain hidden absorption, right?

Let me get this right once and for all. Your use of , suggests that because andre has such prolific and world wide recognition in the world, that his coining of a phrase should be recognized by each and every visitor, if not regular interested parties to this site, and should they not, then woe be them that doesn't understand that quasi-scientific analogy's can be used to infer stupidity on behalf of the beholder. Did I get that right?

[pitchfork]

So with sufficient data on the speakers selecting positions is done primarily by modeling the response.

Maybe in your Parallel Universe. I'd submit that human ears plays the bigger part.

[kasmira]

Originally Posted by pitchfork

Let me get this right once and for all. Your use of , suggests that because andre has such prolific and world wide recognition in the world, that his coining of a phrase should be recognized by each and every visitor, if not regular interested parties to this site, and should they not, then woe be them that doesn't understand that quasi-scientific analogy's can be used to infer stupidity on behalf of the beholder. Did I get that right?

[cborg]

Originally Posted by pitchfork

Maybe in your Parallel Universe. I'd submit that human ears plays the bigger part.

Then how do you select soffit/flash mount positions and how do does it correspond to before and after introducing the presumably angled wall partition?

[johndykstra]

man this thread took a really bizarre turn.

Pitchfork, for what it's worth, Andre spent months with me in private chat going over the finer points of what is my live room/rehearsal space. He was instrumental in it's development. In fact he was instrumental in my caring about this voodoo science as I do.

He did the same for another user a few years back by the name of Spencerc. I sat in on those chats as well and learned a gold mine worth of acoustic technique. While Andre helped him design a studio from the foundation up.

These are only two examples but I'm confident there are a truckload more of such examples, as I've never known Andre to be anything but friendly and helpful... perhaps a bit forked tongued when it comes to a refusal to provide asked for information, but rightfully so in my estimation.

I'm not saying that my personal "vouching" should be of any value to you, but I can't for the life of me figure out why you suddenly decided Andre is a "bad guy" or whatever the heck you're doing here.

[pitchfork]

but I can't for the life of me figure out why you suddenly decided Andre is a "bad guy" or whatever the heck you're doing here.
1 Week Ago 08:48 AM

Holy moly. Why in the heck don't I get notified???

Ok, let me address this now. In the first place...what makes you think "I" thought andre is a "bad guy"??

When I read this...

Just for starters he could be using Invisible Alpha© absorption in that part of the room.

Look John, let's get something straight here...right or wrong, I took it as a if he were suggesting I didn't know what the **** I was doing...as in "invisible" absorption...as in...he doesn't see any..so I must not have used it behind the diffusers...as in...what a schmuck. I mean..after all..why would anyone suggest "Invisible Alpha", if they were telling the previous poster that maybe he just couldn't see the REAL absorption...because of the scale of the model, or whatever. The fact is..he called it "invisible"....like it wasn't even there...like..what a dimwit.


But I wasn't sure..so that's why I said...

I get the feeling some people here don't like it when they themselves don't understand my intent. My apology if that is not the case.

You have to understand something here. I never inferred andre is a "bad guy, " but we've butted heads a few times in the past, and his "tone" was the same then as it SEEMED to be here. Now, if that doesn't clear this up...well too damned bad. This is TWICE I've tried to clear it up. Ain't doin it again.

Andre...I absolutely abhor trying to read between the lines. Next time..if there is a next time...if you have a negative view of my work..spit it out. If this wasn't the case here...then by all means I owe you an apology.

There. Can we move on now?? Cool.

[avare]

Originally Posted by pitchfork

When I read this...

Look John, let's get something straight here...right or wrong, I took it as a if he were suggesting I didn't know what the **** I was doing...as in "invisible" absorption...as in...he doesn't see any..so I must not have used it behind the diffusers...as in...what a schmuck. I mean..after all..why would anyone suggest "Invisible Alpha", if they were telling the previous poster that maybe he just couldn't see the REAL absorption...because of the scale of the model, or whatever. The fact is..he called it "invisible"....like it wasn't even there...like..what a dimwit.

Invisible Alpha© is described in this thread.

But I wasn't sure..so that's why I said...



You have to understand something here. I never inferred andre is a "bad guy, " but we've butted heads a few times in the past, and his "tone" was the same then as it SEEMED to be here. Now, if that doesn't clear this up...well too damned bad. This is TWICE I've tried to clear it up. Ain't doin it again.

I went over the posts that you have made in this forum and I could not find ANY thread where you and I have had contrary discussions. I did find post #30 of this thread and post #11 in this thread.

Why are you dis'ing me? That is not a rhetorical question.

Andre...I absolutely abhor trying to read between the lines. Next time..if there is a next time...if you have a negative view of my work..spit it out. If this wasn't the case here...then by all means I owe you an apology.

My post that you jumped on was not directed at you. I think that you have a fine job with your design. I WAS DEFENDING YOUR WORK!

Confused,
Andre

[pitchfork]

Invisible Alpha© is described in this thread.

WTF!!! And here I thought you might have been making a fool of me. Well, looks like I did a pretty good job of it myself. My BAD!(god I hate that saying)

btw, I'd never heard of that or saw that thread.

Well then..ummmm, my apology notwithstanding,...what can I say andre? Unless I can use my Irish nature as an excuse. ..ie..I have a short temper and my judgement sucks.

I went over the posts that you have made in this forum and I could not find ANY thread where you and I have had contrary discussions. I did find post #30 of this thread and post #11 in this thread.

Holy cow...you went and searched? Well, let me tell you something andre. In case you didn't know...this is FITZ....now do you understand? How bout at Studiotips? How bout at John Sayers? Do those ring a bell? We DID have a few..ummm..let's just call them "disagreements" ....like...ummm, and I hate to bring it up but..how bout..ETHAN WINER??? Now do you remember. But lets just drop it, ok? I've apologized. I made a mistake.

Why are you dis'ing me? That is not a rhetorical question.

Dis'ing you? I don't even know what that means?

My post that you jumped on was not directed at you. I think that you have a fine job with your design. I WAS DEFENDING YOUR WORK!

Man, I can be such a maroon sometimes. Well...in that case...HOLY SHIT. Ok, well that about does it. I didn't understand that.

Let's do this. I'll write "I'm sorry andre"...1k times on the chalkboard while wearing a dunce hat. Will that make up for it. Done deal.

alright, guys, I was wrong, wrong, wrong, wrong .wron wro wr w ...

[Syncamorea]

I hope this thread can stay on track... I'm planning to surface mount my monitors in my mix room rebuild this fall. Since they are active monitors, I will need to provide ventilation for the rear heat sinks. I think it was Glenn that said this can be done if the front edges were sealed well. My plan was to use a well-manicured orifice and make up the gap with a few gaskets of a dense closed cell foam. The well manicured orifice would be a hole cut in the outer layer of the front wall. So my plan was to have a rigid wall made of wood and concrete with the finished side (that which is visible from listening position) wall made of hardwood plywood, glued and screwed to the concrete/wood support wall. Does that materials list/plan sound reasonable? Would it be a bad idea to use Green Glue between the wood/concrete wall and the finish surface plywood covering?

[avare]

Originally Posted by Syncamorea

I hope this thread can stay on track... I'm planning to surface mount my monitors in my mix room rebuild this fall. Since they are active monitors, I will need to provide ventilation for the rear heat sinks. I think it was Glenn that said this can be done if the front edges were sealed well. My plan was to use a well-manicured orifice and make up the gap with a few gaskets of a dense closed cell foam. The well manicured orifice would be a hole cut in the outer layer of the front wall. So my plan was to have a rigid wall made of wood and concrete with the finished side (that which is visible from listening position) wall made of hardwood plywood, glued and screwed to the concrete/wood support wall. Does that materials list/plan sound reasonable? Would it be a bad idea to use Green Glue between the wood/concrete wall and the finish surface plywood covering?

I am having difficulty understanding your description. A pdf of a Sketchup drawing would help.

Andre

[Syncamorea]

I'll give it a shot as soon as I get time. Thanks!

[Syncamorea]

OK, so I need to spend some time learning Sketchup... This is an overhead, cross sectional view through the flush mount.

[IMG] Uploaded with ImageShack.us[/IMG]

So my point earlier was wondering if you had a relatively tight-fitting orifice to flush mount into, could you use a dense foam (shaded black in the drawing) to seal the monitor and not have the typical box built into the wall that the monitor sits in? This plan would leave the heat sink of the powered monitor open to radiate into the space behind the flush mount.

Also, thinking of bonding a thin piece of hardwood plywood ("surface trim" in the drawing) to the structural wall, I mentioned green glue. Basically, I don't want any buzzing or resonance, so I'd like to put an adhesive like liquid nails or possibly use green glue in the gap . Thoughts?

[avare]

Originally Posted by Syncamorea

OK, so I need to spend some time learning Sketchup... This is an overhead, cross sectional view through the flush mount.

[IMG] Uploaded with ImageShack.us[/IMG]

So my point earlier was wondering if you had a relatively tight-fitting orifice to flush mount into, could you use a dense foam (shaded black in the drawing) to seal the monitor and not have the typical box built into the wall that the monitor sits in? This plan would leave the heat sink of the powered monitor open to radiate into the space behind the flush mount.

Also, thinking of bonding a thin piece of hardwood plywood ("surface trim" in the drawing) to the structural wall, I mentioned green glue. Basically, I don't want any buzzing or resonance, so I'd like to put an adhesive like liquid nails or possibly use green glue in the gap . Thoughts?

The drawing and text cleared it up. Yes you can do it the way you described.

Thank you for writing "flush mount" when you meant "flush mount."

Andre

[Syncamorea]

Originally Posted by avare

Thank you for writing "flush mount" when you meant "flush mount."

You're welcome, and thanks for your advice! I'm flushed with excitement for this project.

Off-topic but I've been searching threads here and elsewhere for treatment solutions in small rooms. I'm trying to synthesize it all together and plan to put up a build thread and incorporate some discussion about the trade-offs. At the moment, I'm trying come up with a measurement plan that will be consistent start to finish. I am thinking about upgrading to a decent quality mic. I have a DBX RTA-M and can probably spend around $300, so off I go shopping Gearslutz recommendations!

[OpusOfTrolls]

I have the same mic and it does a great job. Unless you absolutely need direct linear conversion of sound energy to frequency response, the cost really offsets the gain.

[Syncamorea]

I know measurement mics are generally noisy but my DBX seems way noisy. I just found out one of my friends has the Beyer and he's going to let me check it out. Thanks for the advice.

[OpusOfTrolls]

Well in that case, go for it. Mine is exceptionally clean sounding but I take good care of it, and leave it in the case when I don't use it.