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R/E/P => R/E/P Archives => Acoustics in Motion => Topic started by: vladi on October 19, 2009, 11:01:07 am

Title: SOFFIT ATC 110
Post by: vladi on October 19, 2009, 11:01:07 am
HI i am about to soffit a pair of ATC 110 speakers,
the speakers needs to be angled 8 degrees , now  is it OK to just tilt the speakers 8 degrees in a straight wall or should I tilt the wall to.

in other words how important is it to  exactly flush with the front wall.

TNX. VLADI
Title: Re: SOFFIT ATC 110
Post by: vladi on October 19, 2009, 02:52:38 pm
how about turning the speakers upside down, the i wont need to tilt them.

just adjust for the  right height
Title: Re: SOFFIT ATC 110
Post by: Thomas Jouanjean on October 19, 2009, 02:54:09 pm
Here we go to great lenght to flush mount them perfect within the wall and to make the housing/wall as air tight as it can be. So yes, to do it well you need to modify your front wall...

You want an "infinite baffle" type of mounting. Make it nice and neat. Some like them coupled to the front wall, we like them fully decoupled. Different techniques/compromsies that avoid different sets of problems. None of them is perfect. Pick yours Smile

8
Title: Re: SOFFIT ATC 110
Post by: Thomas Jouanjean on October 19, 2009, 02:54:56 pm
vladi wrote on Mon, 19 October 2009 13:52

how about turning the speakers upside down, the i wont need to tilt them.

just adjust for the  right height


Avoid that... Again, if possible.
Title: Re: SOFFIT ATC 110
Post by: vladi on October 19, 2009, 03:02:15 pm
TNX for your reply Thomas,

my Console Bridge ends at 105 cm height, now  can the bass speakers be below that height or must i be able to se them for the best results.

Vladi
Title: Re: SOFFIT ATC 110
Post by: Thomas Jouanjean on October 19, 2009, 05:04:46 pm
Avoid any obstacles. Give them as much free space as possible.
Title: Re: SOFFIT ATC 110
Post by: KB_S1 on October 19, 2009, 05:37:01 pm
Thomas Jouanjean wrote on Mon, 19 October 2009 22:04

Avoid any obstacles. Give them as much free space as possible.


Thomas, for large speakers is there a minimum distance you would try and set between the speaker and the listening position.

Something like Dynaudio M3s for example?
This is slightly following from comments made by a loudspeaker company representative at a seminar recently.
Title: Re: SOFFIT ATC 110
Post by: Thomas Jouanjean on October 20, 2009, 02:45:12 am
KB_S1 wrote on Mon, 19 October 2009 16:37

Thomas, for large speakers is there a minimum distance you would try and set between the speaker and the listening position.

Something like Dynaudio M3s for example?
This is slightly following from comments made by a loudspeaker company representative at a seminar recently.



I would try and have at least 2.1 to 2.4 meters (~7ft to ~8ft) with these.

But the room size and front wall configuration itself will also be a big part of the equation when determining the minimum distance.
Title: Re: SOFFIT ATC 110
Post by: vladi on October 20, 2009, 02:43:33 pm
Thomas could you explain the reasons for not having the speakers up side down.

And is thre any studio that have big speakers that only tilt 5 degrees and have a big console and don´t have any obstacles in the way.

i´m now down to 7 degrees I dont have that extra 90cm for the 5 degrees(see pic)

Vladiindex.php/fa/13619/0/
Title: Re: SOFFIT ATC 110
Post by: Thomas Jouanjean on October 20, 2009, 05:00:40 pm
Real busy here today and tomorrow, will do my best to answer in a couple days max - with a little drawing too  Smile

There are a couple things in your drawing that need to be corrected too. The devil is in the detail, as usual in this field...



Title: Re: SOFFIT ATC 110
Post by: franman on October 21, 2009, 08:43:16 am
I am also curious about your opinion why the speakers cannot be upside down. The only possible complications I see is the study of SBIR with the woofer/floor/ceiling. We often turn speakers with the woofers up, if this works as a better solution and also keeps the woofer/port further away from the vertical center axis in the room.

As Thomas says, there are 'many' things to consider and 'many' different approaches to flush in-wall speaker mounting. We also choose to decouple the speaker, but we do not seek an air-tight opening in the wall.  Also, we have mounted (with great success) up to a max of 10 degrees of tilt. It's all about avoiding first reflections and interference (with regards to positioning). Of course, it is a very complex set of details and we spend A LOT of time coming up with the unique solution for each project. There is no doubt (to me) that lower angle and lower speaker height is better, as this will tend to control reflections off the console surface.

Looking forward to Thomas' reply on the woofer/upside down issue!!

FM
Title: Re: SOFFIT ATC 110
Post by: Thomas Jouanjean on October 21, 2009, 01:41:00 pm
Not upside down, it's indeed because of SBIR! In many cases the calculations show it can really affect the sound, unless (IMO) you 1- have a high enough ceiling 2- with enough/proper slope in it and 3-enough treatment, and the right treatment. Which isn't a given in most places.

Then again, "avoid if possible" isn't "avoid at all costs". There is one or two studios where I actually did put them upside down because the pros wheigthed more than the cons and more important the rooms allowed it.

It's all different shades of grey, and the conditions always differ from one project to the other.

Hence there are only few rules in design, but a lot of guidelines. My guideline is to try to keep them in their "normal position".

Will answer the other question asap!
Title: Re: SOFFIT ATC 110
Post by: Thomas Jouanjean on October 25, 2009, 08:31:57 am
vladi wrote on Tue, 20 October 2009 13:43

Thomas could you explain the reasons for not having the speakers up side down.

And is thre any studio that have big speakers that only tilt 5 degrees and have a big console and don´t have any obstacles in the way.

i´m now down to 7 degrees I dont have that extra 90cm for the 5 degrees(see pic)

Vladi


Vladi,

I started to type something and I actually bumped into an old paper that, while not directly related to the subject, is very close and has a whole part about the Pinna /  HRTF effect.

It is very clear and will show what my point is about the 5
Title: Re: SOFFIT ATC 110
Post by: Thomas Jouanjean on October 25, 2009, 08:57:19 am
So, to make sure it is clear, my point is that in terms of placement (height/angle) you should stay in the area circled on the graph.

http://www.dhorg.net/~astudio/PSW CUE3.jpg
Title: Re: SOFFIT ATC 110
Post by: Greg Reierson on October 25, 2009, 10:13:46 am
Thomas,

Two things. First, it's easy to demonstrate this affect by simply tilting you're head down. HF goes up, for me at least.

Second, I use PMC MB1 XBD floor standing monitors. For proper time alignment (which is easy to verify with pink noise and a bit of head bobbing), PMC specifies that the mid driver be at a 10 degree angle up from the listeners ears. At first I found this a bit strange as the image is slightly elevated, but now I find it completely normal. Imaging is outstanding.

What are your thoughts on their approach? Have you every used either the MB1/2 or BB5 in an installation?

Thanks,


GR
Title: Re: SOFFIT ATC 110
Post by: Thomas Jouanjean on October 25, 2009, 12:07:28 pm
Greg Reierson wrote on Sun, 25 October 2009 09:13

Thomas,

Two things. First, it's easy to demonstrate this affect by simply tilting you're head down. HF goes up, for me at least.




Absolutely, but it's always nice to substantiate a bit Smile - and also put some indicators on what happens and why. This subject is in fact a very complex one.

I feel that when Mixing or Mastering, engineers need to have a faithful representation of the sound stage. Depth, width... Which obvioulsy contain Azimut and Elevation informations. Therefore in your work environment, you need to make sure the conditions are such that you send the right, accurate cues to your brain. When the conditions above are not met, and it's just my opinion, then the information is distorted - when it doesn't have to be.

May seem crazy to some, but I really give all this a great deal of importance.

Greg Reierson wrote on Sun, 25 October 2009 09:13



Second, I use PMC MB1 XBD floor standing monitors. For proper time alignment (which is easy to verify with pink noise and a bit of head bobbing), PMC specifies that the mid driver be at a 10 degree angle up from the listeners ears. At first I found this a bit strange as the image is slightly elevated, but now I find it completely normal. Imaging is outstanding.

What are your thoughts on their approach? Have you every used either the MB1/2 or BB5 in an installation?

Thanks,
GR



I have indeed worked with some PMC speakers MB1 and MB2 - never the BB5. I have both times noticed and heard this problem, which I thought was not acceptable. This is not something I would get used to. IIRC they ask this because the speakers aren't time aligned...

I'm not saying PMCs are bad speakers, but there are a few things in PMC's philsophy that I disagree with and that's one of them.

Take care!
Title: Re: SOFFIT ATC 110
Post by: livingstone on October 25, 2009, 12:55:30 pm
Greg Reierson wrote on Sun, 25 October 2009 09:13

Thomas,
Second, I use PMC MB1 XBD floor standing monitors. For proper time alignment (which is easy to verify with pink noise and a bit of head bobbing), PMC specifies that the mid driver be at a 10 degree angle up from the listeners ears. At first I found this a bit strange as the image is slightly elevated, but now I find it completely normal. Imaging is outstanding.

What are your thoughts on their approach? Have you every used either the MB1/2 or BB5 in an installation?

Thanks,


GR


Hi Greg,

i own a pair of IB2s wich share the same kind of design about time alignement, i built some customs stands to have them exactly at the right height.
true, this way the image is outstanding, but i had some time to be used to it, looking a bit up when turning the knobs to have a true representation of highs (wich is not always easy).
it's like being down the stage just in front of it, it works for some music, but not always.

i had several clients who had a very strange feel about it and i can understand.

i'll change them partly because of this for a pair of Klinger Favre studio 15 (http://klinger-favre-english.blogspot.com/) with 2 velodynes in a month
these speakers are more natural sounding, i think the disposition of apolito is part of it.
i never listened a such soundstage than with these ones.
Title: Re: SOFFIT ATC 110
Post by: Greg Reierson on October 25, 2009, 06:50:46 pm
Thomas Jouanjean wrote on Sun, 25 October 2009 11:07

IIRC they ask this because the speakers aren't time aligned..


Actually, they are time aligned to accommodate their floor standing design. The positioning instructions are very specific.


GR
Title: Re: SOFFIT ATC 110
Post by: livingstone on October 26, 2009, 09:46:30 am
Greg Reierson wrote on Sun, 25 October 2009 17:50

Thomas Jouanjean wrote on Sun, 25 October 2009 11:07

IIRC they ask this because the speakers aren't time aligned..


Actually, they are time aligned to accommodate their floor standing design. The positioning instructions are very specific.


GR


by themselves, they're not time aligned and neither specificaly for their stands,

following PMC instructions to have the mid at 10
Title: Re: SOFFIT ATC 110
Post by: Greg Reierson on October 26, 2009, 10:33:21 am
livingstone wrote on Mon, 26 October 2009 08:46


the position of the drivers has been calculated to be aligned only when the mids are positioned at 10