[gregfisk]

I'm posting this here because I'm building a listening room and using Super V's as my mains for 2 channel music, plus I just like the people who hang out here

So, I have an out building which is 20'x30' with a 10' ceiling. The room will have a kitchen at one end which will take up about 1/3 of the space but will be wide open to the rest of the space. The other 2/3rds will be carpet and dedicated to a listening room. Using the Cardas rule the Super Vs would be about 7' from the front wall and about 5.5' from the side wall.

My question is, at what locations should I run wire for subs, how many should I plan for and does it make a difference how good they are if they are being used to help with room nodes and wired out of phase? I'm also wondering what else I should be doing since I have an open slate at this point as it is just a shell with a concrete floor.

Thanks,

Greg

[TomS]

I'm doing the exact same thing with a new room, about the same size 20x30x11h, concrete floor and concrete block for 3 of the walls in my case. I'm building mine as a "room within a room", double drywall, green glue, and iso clips, working with Jeff Hedback on the design of the build out. This permits the walls and ceiling to work for you a bit more while providing sound isolation both in and out. It's really worth it to invest in the modeling if you're going to pay to finish it out anyway.

If you're supplementing the OB's with sealed servo's, I'd suggest locations for possible wiring in the back of the room and sides at 1/3 and 2/3 down the walls on both sides. That gives you some flexibility to tune from there.

[jparkhur]

I agree with Tom on this one also for placement.  Typically I have seen Danny use the single sub in the back of his rooms to supplement the low end and fill it in.  Usually at the back 1/3 of the room.  I would leave some slack in the RCA so you have some good play in your placement.  With 4 subs in the H Frame of the Super V, I would gander a guess that two would be more than enough, but you could always add what you want.  Also, I like the sound of a sealed sub in the back with the Super V's or Super 7's.  You could also do dual 12's with the new hypex amps from Rhythmik and do one on each side for 8 total 12's around the room.  Overkill?   I have no ob subs, but two 15's in front and two 12's in back.  I had to load them at the way back of the room due to kids, but works out really well.

Jon

[gregfisk]

Thanks Guys,

I changes the subject title to broaden what I'm trying to learn here.

Thank you Tom, it sounds like we have very similar rooms, perhaps I should contact Jeff Hedback and get more info. I'm also going to be using RC channel on the walls and ceiling to try and keep the sound in. At the kitchen end of the building I'll be using a double wall as this is the end that has the closest house.

So, if I run wiring for subs 1/3rd back and 2/3rds back and the speakers are about 7' into the room, the woofers would be against the wall about 3' in front of the speakers. If I put the woofers 2/3rds back they would be about 5' behind my seating position.

jparkhur, thanks for your input. I guess as long as I run the wire now, I can go as crazy as I want at a later date .

I'm wondering if the Cardas room set up guide applies to OB speakers or if they should be set up differently?

Something else I'd really like to get some input on is what location to put the audio gear? If the speakers are 7' into the room is a audio rack going to effect the sound stage located on the front wall? Or, would it be better to put the audio gear on the side wall closer to the listening chair? I noticed Danny with his audio gear on the floor which makes since as it keeps from having to use a tall rack. 

Greg

[Danny Richie]

Typically you will get more of a room boom in the corners of the room. So when we go to shows we use a pair of 12" sealed servo subs in the back corners running out of phase from the main speakers. This does away with any low frequency gain that is in the back of the room.

You can experiment with moving them forward as needed.

[Folsom]

When using swarm technique, 4+, isn't part of the intent to accept more of the room's "issues" but given that there's only so many placement options, you'll inevitably create some cancellation and be able to lower the volume and directionality to help, without a lack of bass due to quantity and placement? You can't see Duke's drivers, but I assume they are down or up.

If that run-on makes any sense, too...

Forgive me if I misunderstand, but it seems like swarm technique is mostly to give up on taming a perfect bass response, and just achieve something that's somewhat believable for the room you're in. But given how it functions, it kind of achieves the prior anyway.

Also I assume the origination was thinking of pairing with some pretty low frequency playing speakers, without the intention of playing too much in the range the OB quad's are meant to cover? 

[PDR]

......when we go to shows we use a pair of 12" sealed servo subs in the back corners running out of phase from the main speakers. This does away with any low frequency gain that is in the back of the roo

This is what I do in my room with the Super Vs.......mine are dual 12" non servo that I happened to have.
I used REW to fine tune.......works very well for me.

[Danny Richie]

Also I assume the origination was thinking of pairing with some pretty low frequency playing speakers, without the intention of playing too much in the range the OB quad's are meant to cover? 

Even though the open baffle servo woofers are playing flat down into the teens it still works out really well with the rear sealed woofers. The front woofers alone (even in an open baffle) will put some really low frequency energy through the room. It loads the room differently than sealed subs, but still can create some loading. And tweaking the rear subs can even things out nicely. It can also add additional low end tightness and power especially when the room gets big.

And usually we set the rear subs to cover about 25Hz and down. And not only do they add some additional foundation, but they also improve the imaging. I know that sounds weird, but even changing the damping settings on the rear subs effects the imaging. They also go rather unnoticed at those low settings. You really never know that they are there unless you turn them off.

[*Scotty*]

You know the rear woofers are functioning correctly when the sound-stage image collapses against the front wall when they are turned off.
In fact you may not even realize the rear subs are on until you turn them off.
Scotty

[gregfisk]

Typically you will get more of a room boom in the corners of the room. So when we go to shows we use a pair of 12" sealed servo subs in the back corners running out of phase from the main speakers. This does away with any low frequency gain that is in the back of the room.

You can experiment with moving them forward as needed.

I am fortunate that I can use room treatment at will and I want to wire for the future with the ability to add subs as well. Like I mentioned, the kitchen "and a small bathroom" cover the back 1/3rd of the room so the farthest I could place subs would be about 2/3rd back from the front wall. I'm confused as to why the subs if wired out of phase need to be of high quality, aren't they just sucking out room nodes or are they actually adding something to the music like more bass?

PDR, I will definitely use some kind of measuring tool once I have some time on the system, right now I just want to make sure I don't overlook something important. By the way, I really like your Super V design, very innovative!

I'm still wondering at what location I should put my audio gear, on one hand I need to worry about wire length, on the other I have to worry about messing up the sound stage. I see people normally putting the audio gear in between the speakers which I assume is for the shortest wire runs but I also see people put the gear closer to them probably for ease of use

If you had an open slate and could run smurf tube all around the room at what location would you put your gear?

Thanks for all your input,

Greg

[Folsom]

I actually love stereo subwoofers. I've wanted them again since I moved. Personally I am not yet convinced you can replace what they do.

The swarm is interesting though. One thing about them is they can hide, depending on size.

[Danny Richie]

I'm confused as to why the subs if wired out of phase need to be of high quality, aren't they just sucking out room nodes or are they actually adding something to the music like more bass?

Quality and control are very important or you'll just be adding more boom to the room.

I'm still wondering at what location I should put my audio gear, on one hand I need to worry about wire length, on the other I have to worry about messing up the sound stage. I see people normally putting the audio gear in between the speakers which I assume is for the shortest wire runs but I also see people put the gear closer to them probably for ease of use

Really high quality cables are often not cheap and can get real pricey when lengths get long.

I like gear between the speakers and on the floor. This keeps cables short and gear out of the sound stage.

[gregfisk]

Quality and control are very important or you'll just be adding more boom to the room.

Really high quality cables are often not cheap and can get real pricey when lengths get long.

I like gear between the speakers and on the floor. This keeps cables short and gear out of the sound stage.

Good point,

I wasn't thinking about the cable cost and once I have my own room I will be experimenting more with different cables. Perhaps a low wide shelf would be the way to go. I like PDRs solution, it's low to the ground and has an industrial look.

Thanks,

Greg

[JLM]

Please read Floyd Toole's 'Sound Reproduction' (impressive resume) where he goes into extensive explanation of swarm theory. The concept is to even out peaks and valleys in a room which only be done with multiple bass sources. Random/multiple placement options should be considered so you have flexibility.  Duke LeJune here at AC is a big proponent of swarm and sells swarm systems.  Note that with swarm you really don't need (or want) frequency response from your mains to cover bass frequencies.

I built a Cardas room (8' x 13' x 21' - the smallest room I'd recommend to avoid first reflection issues) with his speaker/listener near field setup and love it. Recommend isolating your room from the outside (building) walls to keep outside sounds (even wind noise) out.  Note that you might want a wider room for A/V use.  I always had a dream to try a room within a building, but too expensive/inconvenient for me.

As far as equipment location goes, I'd keep it in the middle of the speakers and against the front wall (less wire to buy and have R/F issues with) and in a small open rack (unless you want to go nuts with built-ins to isolate the gear from room vibrations and buy custom remote controls to bypass glass doors behind the speakers).  I use a 20" x 16" x 22" Ikea nightstand.

[bdp24]

Quality and control are very important or you'll just be adding more boom to the room.

Really high quality cables are often not cheap and can get real pricey when lengths get long.

I like gear between the speakers and on the floor. This keeps cables short and gear out of the sound stage.

A good way to deal with this whole issue is to, if you are able, have your source components and pre/pro wherever you want (against the front wall, by your listening position, etc.), and run a balanced output interconnect from your pre to your balanced-input power amp/s, which is/are on a low rack/table/stand between your speakers. The cable from your pre to your power can be as long as necessary because of being balanced, and the cost of your speaker cables will be as low as possible. Even better, run the balanced signal to balanced-input monoblock amps, each beside it's speaker, with speaker cables as short as possible (mine are 1' long). You can get really good cables if you're buying only a foot of them! Of course, your interconnect will cost more than if your power amp/s was/were by your pre, so you're going to pay either way. And it works only if you have a balanced system, or really low-capacitance cables at least.

[gregfisk]

Please read Floyd Toole's 'Sound Reproduction' (impressive resume) where he goes into extensive explanation of swarm theory. The concept is to even out peaks and valleys in a room which only be done with multiple bass sources. Random/multiple placement options should be considered so you have flexibility.  Duke LeJune here at AC is a big proponent of swarm and sells swarm systems.  Note that with swarm you really don't need (or want) frequency response from your mains to cover bass frequencies.

I built a Cardas room (8' x 13' x 21' - the smallest room I'd recommend to avoid first reflection issues) with his speaker/listener near field setup and love it. Recommend isolating your room from the outside (building) walls to keep outside sounds (even wind noise) out.  Note that you might want a wider room for A/V use.  I always had a dream to try a room within a building, but too expensive/inconvenient for me.

As far as equipment location goes, I'd keep it in the middle of the speakers and against the front wall (less wire to buy and have R/F issues with) and in a small open rack (unless you want to go nuts with built-ins to isolate the gear from room vibrations and buy custom remote controls to bypass glass doors behind the speakers).  I use a 20" x 16" x 22" Ikea nightstand.

JLM, Very good information, Good advice about keeping noise out, I'm fortunate that the two houses closest to me aren't that close. I will pick up Floyd's book and have a read. Regarding flexibility, I'm thinking about some type of raceway that looks like molding, that way I can run wire around the room later without a problem. I will also be running wire in the walls and smurf tube just is case.

Also, when using the Cardas set up did you still feel you needed room treatment and did you use any? If you used treatment how much difference did it make? My understanding is that the Cardas layout eliminates a lot of the inherent problems to begin with and my room at 20'x30'x10' is almost exactly the example they use.

If anyone else has set up a Cardas layout I would like to know what they feel the outcome was.

Regarding a rack I currently use an 8 foot commercial equipment rack as my ceiling in my house are 17' tall. What I don't like about it even thou it's on wheels is I have to pull it away from the wall to get to the back of the equipment which I find to be a hassle. I would love to have something build in but it still makes it hard to swap out gear which I'm liking to do more and more.

bdp24, thanks for your insight. I agree with a balanced system I would have more flexibility, I will give that some thought.

Thanks to everyone for your input so far, it is appreciated.

Greg

[Russtafarian]

Based on my experience with swarm subs, I would say be prepared to experiment a lot with sub placement.  So keep your wiring options as flexible as possible.

I have two 15" sealed subs on either side of my listening couch, out of phase with the front speakers.  I also have four 8" passive Velodynes that I have tried in various places across the side and front walls.  My "random" placement of small subs (1 left wall, 1 front wall, 2 right wall at different heights) was based on available space within the layout of the room.  Combined with the two 15" sealed, I got fairly even and smooth coverage, certainly better than what I got with just two subs.

Then I tried a layout that I use for live concert speaker setup.  I set the four small subs in a horizontal line on the front wall centered between the main speakers.  The FR is more peaky than the random placement and I had to notch at 80hz.  But I get far more midbass punch without over-exciting room modes.  I can tighten or fatten the overall punchieness of the system by adjusting the Q of the 80hz notch filter.

I'm liking it but it took a lot of experimentation to get to this point.

Russ

[bdp24]

JLM, Very good information, Good advice about keeping noise out, I'm fortunate that the two houses closest to me aren't that close. I will pick up Floyd's book and have a read. Regarding flexibility, I'm thinking about some type of raceway that looks like molding, that way I can run wire around the room later without a problem. I will also be running wire in the walls and smurf tube just is case.

Also, when using the Cardas set up did you still feel you needed room treatment and did you use any? If you used treatment how much difference did it make? My understanding is that the Cardas layout eliminates a lot of the inherent problems to begin with and my room at 20'x30'x10' is almost exactly the example they use.

If anyone else has set up a Cardas layout I would like to know what they feel the outcome was.

Regarding a rack I currently use an 8 foot commercial equipment rack as my ceiling in my house are 17' tall. What I don't like about it even thou it's on wheels is I have to pull it away from the wall to get to the back of the equipment which I find to be a hassle. I would love to have something build in but it still makes it hard to swap out gear which I'm liking to do more and more.

bdp24, thanks for your insight. I agree with a balanced system I would have more flexibility, I will give that some thought.

Thanks to everyone for your input so far, it is appreciated.

Greg

The Cardas Golden Ratio deals with room modes and bass frequencies primarily. The dimensions of the room can't be changed, so if you have room boom, bass traps will be necessary. The other issue is reflections of higher frequencies off the walls, floor, and ceiling of the room. If your floor is carpeted, that leaves the ceiling and walls. The main culprit there is the first reflection point from the speakers off the side walls to your listening position. If you put up panels at those two locations (the midway point on the two walls between you and your speakers), you've taken care of the main room-related issues. Then use diffusion (bookcases, record racks, acoustical panels) on the wall behind you, and you've covered just about everything. This is a simplified version of room acoustics issues, of course.