my profile | my password | search | faq & rules | forum home

» Film-Tech Forum ARCHIVE   » Operations   » Film Handlers' Forum   » Suggestions on EQ-inga small room (Page 1)

This topic comprises 2 pages: 1  2

Author Topic: Suggestions on EQ-inga small room Bernie Anderson Jr Master Film Handler Posts: 435 From: Woodbridge, New Jersey Registered: Apr 2000 posted 12-03-2008 04:57 PM                        I've talked to different people about this, but is there any rule of thumb for EQ-ing small theatres or screening rooms? I've been told to roll off the low end sooner and don't drop off the high end as much compaired to the recommended academy curve. Any thoughts on that? Bernie  |  IP: Logged Louis Bornwasser Film God Posts: 4441 From: prospect ky usa Registered: Mar 2005 posted 12-03-2008 09:20 PM                        The roll off specified is designed for all rooms. That is the point of the specification. The only exception is "large" rooms with special circumstances. In fact your small room and the mixing suite should be the same; life is easier in a small room. Louis  |  IP: Logged Christos Mitsakis Expert Film Handler Posts: 242 From: Ag.Paraskevi, ATHENS, GREECE Registered: Sep 1999 posted 12-04-2008 01:35 AM                     Eq flat up to 2KHz falling 1.5dB per octave afterwards, or go up to 4KHz flat, then fall 3dB per octave. Both will give you acceptable responce for small rooms. Christos.  |  IP: Logged Tony Bandiera Jr Film God Posts: 3067 From: Moreland Idaho Registered: Apr 2004 posted 12-05-2008 02:25 PM                     quote: Louis Bornwasser The roll off specified is designed for all rooms. And that is a problem. Smaller rooms, when using an RTA and pink niose, require {LESS} roll-off to avoid sounding {dull}. Edited text in {} The manual for a Goldline RTA goes into detail explaining the differences in roll off for large and small rooms, and the reasons why. (Has to do a lot with reflection times affecting the response at higher frequencies.) I think there is a Goldline manual in our "Manuals" section here.. unfortunately, I sold my Goldline and don't have the manual anymore. [ 12-05-2008, 07:08 PM: Message edited by: Tony Bandiera Jr ]  |  IP: Logged Max Biela Film Handler Posts: 89 From: Dortmund, Germany Registered: Sep 2003 posted 12-05-2008 02:56 PM                     It is the other way around: very small rooms require an almost flat EQ with very little roll off. See SMPTE paper published in the "Technical Guidelines for Dolby Stereo Theaters" in the manual section.  |  IP: Logged Cameron Glendinning Jedi Master Film Handler Posts: 845 From: West Ryde, Sydney, NSW Australia Registered: Dec 2005 posted 12-05-2008 03:05 PM                     I agree with Max, close to flat in a small room  |  IP: Logged Tony Bandiera Jr Film God Posts: 3067 From: Moreland Idaho Registered: Apr 2004 posted 12-05-2008 07:06 PM                     Yep, Max is right, I had that backwards.. my bad.. I'll edit the original post.. Sucks getting old...  |  IP: Logged Pete Naples Phenomenal Film Handler Posts: 1565 From: Dunfermline, Scotland Registered: Feb 2001 posted 12-09-2008 03:39 AM                     OK Here's a quandry. Define a small room? Dimensions/Volume, or Nº of seats?  |  IP: Logged Bernie Anderson Jr Master Film Handler Posts: 435 From: Woodbridge, New Jersey Registered: Apr 2000 posted 12-11-2008 06:44 PM                        Small room: small screening room with maybe 10 seats to a small multiplex auditorium with maybe 50 seats (35'x50')  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 12-11-2008 07:06 PM                     I tend to sub-divide the small rooms into the less than 40-feet from screen to rear wall. The Very-Small room for me is on the order of 20-feet from screen to rear-wall. Like any EQ...use the analyzer but you best listen to your result with known film (a track you have heard in several rooms) and preferrably with several different pieces of material and dialog as well as music better be part of the material. Steve  |  IP: Logged Scott Norwood Film God Posts: 8146 From: Boston, MA. USA (1774.21 miles northeast of Dallas) Registered: Jun 99 posted 12-12-2008 08:09 AM                        Semi-related question: some setups and rooms seem to sound really great for music and lousy for dialogue, while others are the opposite. Why? Is it the extend to which the room is "too live" or "too dead" (what is the technical term for this?)? Is it the setup (EQ, crossover points, etc.) of the system? Large rooms also seem to have low-frequency issues. I'm familiar with one (large 1920s house) that has a nasty bump at around 200-250Hz. How does one go about fixing something like this? Is it wrong to try to fix these issues with EQ alone? Is there material that absorbs certain frequencies that can be installed and, if so, how does one know where to install it and how much to use? Is it just a matter of trial-and-error? What about rooms that have dips at certain frequencies?  |  IP: Logged Louis Bornwasser Film God Posts: 4441 From: prospect ky usa Registered: Mar 2005 posted 12-12-2008 10:12 AM                        The larger, the more reflective room; you will have dialog problems. (if it is really large and reflective, you may have to EQ the normal way, then corrupt the eq to aid articulation.) You do this with all channels off except center; work only with dialog; when finished eq the other channels normally. Lastly, raise the center only 3-6 db if needed. I feel like a real old timer on this since this was normal procedure in the 1930-1950's. Louis  |  IP: Logged Robert Minichino Master Film Handler Posts: 350 From: Haskell, NJ, USA Registered: Dec 2005 posted 12-12-2008 01:04 PM                        From the opposite perspective (3000 seat house), Louis is absolutely right. Our theatre sounds great on music with minimal EQ, but dialog is unintelligible without a substantial and wide hump around 400Hz in the center channel. For deciding what a small room is, my guide would be a combination of the largest dimension and room volume. The larger the largest dimension is, the lower in frequency the lowest room mode is, so that dictates your bass frequency response. The larger the volume of the room the less high frequency reverberation there is with respect to low frequencies. In almost any conceivable home theatre or equivalently-sized screening room I'd run without EQ (or EQ so speaker's near field response is flat) on the high frequencies, and use a combination of room treatments and EQ to get a slightly rising response as you go down in frequency from 120Hz (3dB/oct) with no obvious interaction from room modes. It's been my experience that this combination gives the most "real" bass response in smaller rooms.  |  IP: Logged John Hawkinson Film God Posts: 2273 From: Cambridge, MA, USA Registered: Feb 2002 posted 12-12-2008 05:12 PM                     So, err, why are people asking what defines a small room? EQ the room to the curve and see how it sounds! --jhawk  |  IP: Logged Pete Naples Phenomenal Film Handler Posts: 1565 From: Dunfermline, Scotland Registered: Feb 2001 posted 12-13-2008 02:26 AM                     Just interested in what people consider a small room, nothing more. I've got one tiddler in the Republic of Ireland, it aligns with very little action from the equalizers and sounds great. I put a lot of this down to the fact that you are sitting practically in the throat of the speakers. You are hearing more direct sounds as opposed to the predominantly reverberant field you would hear in a large room. The room being very well damped is helping matters too.  |  IP: Logged

All times are Central (GMT -6:00)

This topic comprises 2 pages: 1  2

Printer-friendly view of this topic

Hop To: Select a Forum: Category: Operations -------------------- Digital Cinema Forum Film Handlers' Forum Large Format Forum Ground Level Feature Info, Trailer Attachments & REAL Credit Offsets Category: Community -------------------- Film-Yak Film Handlers' Movie Reviews The Afterlife Bob Maar's Joke-A-Thon Category: Classified -------------------- Equipment and Supplies Wanted/For Sale Help Wanted/Seeking Employment Category: System -------------------- Software Beta Testing Forum

The Film-Tech Forums are designed for various members related to the cinema industry to express their opinions, viewpoints and testimonials on various products, services and events based upon speculation, personal knowledge and factual information through use, therefore all views represented here allow no liability upon the publishers of this web site and the owners of said views assume no liability for any ill will resulting from these postings. The posts made here are for educational as well as entertainment purposes and as such anyone viewing this portion of the website must accept these views as statements of the author of that opinion and agrees to release the authors from any and all liability.