Very unusual room - need advice

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Spirit

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Very unusual room - need advice
« on: 12 May 2018, 11:57 pm »
I have attached a drawing of my situation.
This is the basement of my home.
It is completely finished with drywall on all walls and ceiling. The celing is about 7 feet high.
The drawing is NOT to scale - particularly the distance from the speakers to the chair.
Here are some notes:
1: the areas that I am most concerned about are marked in dark marker:
The areas behind the couch and the area in front of the speakers.
2: the speakers are Apogee Duettas - which are dipole ribbons. So the sound emanates from the front and the back.
3: in case it is not clear: the width of the room is 33 feet (9.5 feet + 14.5 feet + 9 feet for the width of the alcove behind the speakers.)
I think you can see why I consider this area to be more of a "space" as opposed to a "room".
Any direction that can be offered would be great.  If you can point me to actual products that GIK makes  so that I can see what they are would be great!


Glenn Kuras

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Re: Very unusual room - need advice
« Reply #1 on: 16 May 2018, 02:55 pm »
Sorry about the delay getting to you. We don't get to check AC all that much so I would recommend filling out the following form to give us your information. I can then have one of my designers directly work with you. ;) 
http://www.gikacoustics.com/acoustic-advice-form/

Hipper

Re: Very unusual room - need advice
« Reply #2 on: 18 May 2018, 06:48 pm »
That is an awkward set up! Can you place the speakers and chair elsewhere in the room. I would suggest that finding the best locations is the start, then look at room treatment.

The way you have it in the diagram seems too lopsided for balanced sound from both speakers. The left speaker is directing sound onto a wall nearer then the right speaker, and also against a nearer back wall. You could try a diagonal arrangement which some have had success with and which I would think could suit your situation. The speakers would be placed either side of the top right corner with your chair roughly where it is now. You should then move the speakers and chair around a bit to get the best, most balanced sound. It takes time to do this but should be worth it. It can help a lot to use a measuring device to do this, but that will add to the learning you need to do. Room EQ Wizard is recommended (there's info on the GIK site about how to use this).

After that, listen to GIKs advice.

JLM

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Re: Very unusual room - need advice
« Reply #3 on: 18 May 2018, 10:02 pm »
From what I can gather the top/right corner looks to have a clear floor space of about 18 foot x 20 foot before running into the highlighted corner where the chair is shown.  Can you center the system closer into that corner (speakers centered 9 - 10 feet from the corner)?  Should be enough space, even with dipoles, oriented either way or as Hipper mentioned on an angle.  Best to keep the speakers and the listening position away from walls to minimize room effects. 

I have an 8ft x 13ft x 21ft room, which is the Cardas Golden Cuboid and the setup is also ala Cardas (roughly 6 foot near-field triangle), but my speakers are traditional (forward facing drivers).  I have six GIK 244 panels plus three bookshelves on the side walls, but they offer almost no benefit in this "ideal" situation no matter how I try to orient the panels and the speakers (the GIK panels work miracles elsewhere).  The system images really gels in the listening chair.

Room impact on sound reproduction is greatly under rated.  Treatments aren't cure-alls, better thought of as a band-aid.  Recommend reading Floyd Toole's "Sound Reproduction".

Speakers should be selected for the given room (space).

Spirit

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Re: Very unusual room - need advice
« Reply #4 on: 18 May 2018, 11:05 pm »
That is an awkward set up! Can you place the speakers and chair elsewhere in the room. I would suggest that finding the best locations is the start, then look at room treatment.
You are correct - it is an awkward setup!! But unfortunatly it is what it is - I can't move it anywhere. A drawing just represents an area but in real life what is blank on the drawing is full of other "stuff" in real life.

Quote from:
The way you have it in the diagram seems too lopsided for balanced sound from both speakers.
I know all too well!

Quote from:
The left speaker is directing sound onto a wall nearer then the right speaker, and also against a nearer back wall. You could try a diagonal arrangement which some have had success with and which I would think could suit your situation. The speakers would be placed either side of the top right corner with your chair roughly where it is now. You should then move the speakers and chair around a bit to get the best, most balanced sound. It takes time to do this but should be worth it. It can help a lot to use a measuring device to do this, but that will add to the learning you need to do. Room EQ Wizard is recommended (there's info on the GIK site about how to use this).

After that, listen to GIKs advice.
As mentioned above - I can't move anything - so I did contact GIK today and dealt with a very nice young man named Zak who sent me his suggestions and a quote. Now I have to figure out how to pay for it!

Spirit

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Re: Very unusual room - need advice
« Reply #5 on: 18 May 2018, 11:09 pm »
From what I can gather the top/right corner looks to have a clear floor space of about 18 foot x 20 foot before running into the highlighted corner where the chair is shown.  Can you center the system closer into that corner (speakers centered 9 - 10 feet from the corner)?  Should be enough space, even with dipoles, oriented either way or as Hipper mentioned on an angle.  Best to keep the speakers and the listening position away from walls to minimize room effects. 

I have an 8ft x 13ft x 21ft room, which is the Cardas Golden Cuboid and the setup is also ala Cardas (roughly 6 foot near-field triangle), but my speakers are traditional (forward facing drivers).  I have six GIK 244 panels plus three bookshelves on the side walls, but they offer almost no benefit in this "ideal" situation no matter how I try to orient the panels and the speakers (the GIK panels work miracles elsewhere).  The system images really gels in the listening chair.

Room impact on sound reproduction is greatly under rated.  Treatments aren't cure-alls, better thought of as a band-aid.  Recommend reading Floyd Toole's "Sound Reproduction".

Speakers should be selected for the given room (space).
Thanks for the reply JLM. I wish I could move things around but I can't. I just have to make the best of it. Truthfully it really is not that bad - surprisingly - but I want to make it as good as I can.
I totally agree with you that room impact is definitely under rated. Audio hobbyists will go out and pay thousands of dollars for cables and power cords but don't think to invest that money in acoustic treatment that will benefit the system so much more.

Hipper

Re: Very unusual room - need advice
« Reply #6 on: Yesterday at 10:02 am »
If following GIK's advice doesn't complete the job you could use Digital Signal Processing (DSP) or some sort of equaliser.

I use a Behringer DEQ2496 which is complicated to use. Better and easier would be a Mini DSP with Dirac, or if you are PC based, just Dirac.

These will act like very sophisticated tone controls.

JLM

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Re: Very unusual room - need advice
« Reply #7 on: Yesterday at 11:39 am »
I'd experiment by pulling the chair away from the small corner.  Don't be afraid of nearer field listening to further reduce room effects.   Then apply treatments, but only as needed, even Toole listens in a quite ordinary room at home.  The western ear is acclimated to listening in rooms, again of the ideal shape (in ratios of 5:8, height to width and width to length).   Treatments can be in various forms but generally fall into two camps: absorption and diffusion.  Absorption can be a simple as stuffed furniture and can be overdone (sounding muffled).  Diffusion is simply based on laws of physics and the size of sound waves, so most commercially available products are only effective down to roughly 1100 Hz (7 inches deep), and many aren't very effective as they aren't made of reflective materials.  I use 3 tall randomly filled bookshelves on the side walls half way back into the room.

Finally DSP (or EQ) should only be thought of as the icing on the cake and then only carefully applied.  These can only be effective at a single location in the room.  They absolutely shouldn't be used to make up for poor speaker performance.  And if done by ear can really mess up the sound and even destroy your gear, because deep dips cannot be addressed.  Deep dips in frequency response, like -30 dB, which can occur requires 1,000 times the wattage to compensate due to the logarithmic relationship between power and sound pressure.  This 1,000 fold power increase would clip the amp at higher sound pressure levels and send a torturous signal to the speaker, likely frying the voice coils out.  If using DSP/EQ, best to do it with unit that includes a microphone and does it automatically.  Note that a narrow dip can't be heard anyway.

Spirit

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Re: Very unusual room - need advice
« Reply #8 on: Yesterday at 02:09 pm »
Thank you Dipper and JLM for your replies and advice and also for be so giving of your time to write!
DSP: I guess I should have written this in my OP: I am using a Dspeaker Anti Mode 2.0 already. This made an enormous improvement on cleaning up the sound below 500hz. My goal was to see whether adding some absorption or diffusion would help wilth the higher frequencies which the Dspeaker does not tame. Zak's recommendation was to place floor to ceiling absorbing panels both in front of the speakers in the alcove area and behind the listening chair.
I did some sleuthing on the internet last night and came across a newsletter written about 30 years ago by the late Jason Bloom -  the President of Apogee. In the newsletter there is a section titled: "the Apogee 10 Commandments". Commandment #1 is; and I quote:
"1. Never use heavy acoustical damping directly behind the loudspeaker."
Very interesting - you must admit.
After commandment #10 and in conclusion Mr. Bloom wrote:
"Follow these commandments wisely, the alternative could be wandering around in an audio desert for 40 years!"
How prophetic was that statement!

poseidonsvoice

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Re: Very unusual room - need advice
« Reply #9 on: Yesterday at 03:08 pm »
Spirit,

Since you mentioned the commandments, let’s publish the whole thing for all to see:

The Apogee Ten (and half) Commandments

1. Never use heavy Acoustic damping directly behind your loudspeaker.
2. Never “toe-in” Apogee speakers more than 3/8” (most people place them directly parallel to the rear wall).
3. Always bi-wire your speakers for maximum performance.
4. For most rooms speakers should be placed a minimum distance of 68” to a maximum of 84” from inside edge of one speaker to another. (Obviously room size and seating positions will dictate the final installation.)
5. Always place your Apogee speakers 36”-60” from the rear wall depending on model. Generally the larger the model the greater the distance.
6. Do not place your speakers closer than 10” to the side walls.
7. Never use high capacitance speakers cable
8. With the appropriate Apogee speaker always use the factory provided “plumb bob” to determine the manufacturer’s recommended rake angle or tilt back angle with the exception of the Diva.
9. Always secure your speaker cable connection but do not over torque the 5 way binding posts.
10. If after following commandments one through nine you ‘are still unsure of some aspect, our tenth commandment is to call us (replace it with email to Graz). Apogee (graz) never frowns on any of your questions no matter how great or small.


Best,
Anand.