The "3 foot from the side wall" rule for SDAs.

audio_alan

All,

Regarding the "3 foot from the side wall" rule for SDAs, here's my situation...

I have a living room with a couple "nooks" on either side of a fireplace. I'd like to recess my SDA-SRSs into the nooks (as well as the equipment), but only deep enough to where the front of the speakers are flush with the front of the fireplace wall. I know SDA's like to be close to back walls, so you can see how the current setup is less than optimal (not to mention they are currently too close to the side walls).

Oh, and I don't use the fireplace, so I have no concerns about them getting too hot or anything. That also would allow me to mount my flat screen just above the mantle without problems as well...

Any problems with doing that?

Thanks,

Alan

audio_alan

My picture won't post for some reason. Here's a link to my original post when I bought the SRS's:

http://www.polkaudio.com/forums/showpost.php?p=1421138&postcount=16

kawizx9r

Here you go.







-Freddy

audio_alan

Thanks! For some reason it didn't post, and it wouldn't let me try to add them again, saying they were already attached...

audio_alan

This might make it a little clearer. The attached drawing is a top view of the room - the left side being what the setup is now, and the right side is what I'm proposing. Make sense?

Alan

F1nut

None of it is going to be ideal, but your new idea might result in better sound.

ESavinon

There's only one way to find out.

audio_alan

F1nut wrote: »

None of it is going to be ideal, but your new idea might result in better sound.

Unfortunately, without moving, that's the area I have to deal with...

ESavinon wrote: »

There's only one way to find out.

True, but there are shelves back there. If it were as simple as pushing them back, I probably would have already tried it. But since I'm going to need to rip out a couple shelves, I thought I'd poll the group first...

Anyone tried something similar? I'm hoping I don't get some strange interference with them being in a hole like that. Perhaps if I installed acoustic treatment / bass traps behind them, I could minimize any weirdness. ???

Face

How's the low end now?

Toolfan66

Alan,

I would not do that. If I was you I would go with room treatments, and for gods sake SPIKE them, get them off the floor..

IMO rooms that are not that ideal for SDA's room treatments are the only thing to help balance the sound..

Just my .02

falconcry72

I would imagine that your bass response will get better in the nooks, and the imaging shouldn't see much difference since either way they have less than a foot on the sides. Boths ways are not particularly SDA friendly, but that doesn't mean they'll sound bad, it just means they won't sound as good as they could.

The one aspect that will improve greatly when you move them into the nooks, and put the flat screen over the mantle, is that your room will look a hell of a lot better!:)

I say move'em!!!:D

audio_alan

Face wrote: »

How's the low end now?

The low end isn't that great right now, but the driver "leak down" test shows that I lose pressure fairly quick. I need to replace a few drivers that have tears in them (which lets air escape), so I'm assuming it will improve somewhat (or drastically?) after I replace them...

TOOLFORLIFEFAN wrote: »

Alan,

I would not do that. If I was you I would go with room treatments, and for gods sake SPIKE them, get them off the floor..

IMO rooms that are not that ideal for SDA's room treatments are the only thing to help balance the sound..

Just my .02

Yeah, spikes are in the plans. Do you think I'd get some weird echoes coming out of the "nooks"? How much sound really comes out of the back/sides of the cabinet? I'm concerned that if I don't get them closer to a back wall, they'll never put out the bass that I'm looking for...

audio_alan

falconcry72 wrote: »

....

The one aspect that will improve greatly when you move them into the nooks, and put the flat screen over the mantle, is that your room will look a hell of a lot better!:)

I say move'em!!!:D

Falconcry - Yeah, that's one of my main motivations (and to try to get better imaging and bass, of course). It's fairly cluttered right now with the speakers and equipment domninating about 1/4 of the room. If I do that, it will really open up the room.

So am I hearing that the "3 foot" rule applies to the side of the cabinet also, and not just that the front plane of the speaker needs to be 3 ft from a side wall? If not, and it really only applies to sound projected from the front (so you don't get immediate reflections from the sound coming forward out of the speakers), I would think pushing them back into the nooks would conform more to what Polk recommends in the manual.

audio_alan

Ok, one more post might help summarize my options (sorry for the triple postings).

Basically, I see three options at this point:

A) Leave it alone - Probably the worst idea.
Remove the shelves and recess the speakers into the nooks, but possibly have interference on the inside (or all) walls in the nook (?).
C) Move them closer to the center of the room, but don't recess them (possibly improve imaging, but not much more bass)

(The lines are what I imagine is happening with sound reflections. Obviously "A" should be the worst).

Note how on option "B" the front of the speakers are technically 3' from the side walls, but the cabinets are not. This is what I'm trying to figure out. Is this really bad, or does that actually conform to the 3' rule?

Thanks for the input so far!

Alan
P.S. Sorry for the quick/sloppy paint drawing, but I figured it would help everyone visualize what I'm thinking. One thing to note, the nooks probably aren't near as deep as the drawing would lead you to believe. Recessing them would probably make the Speakers about 6-8" off the rear wall, which would be perfect in a regular wall setup...

Audioquest

OPTION 1: I would move the speakers close to the TV, and put the sub on one side and the audio rack on the other, outside of the speakers. A little closer together is better than right beside the walls. Better yet, move the sub to the other end of the room, and the rack to the side wall out of the way.

OPTION 2: sell them to me!

yeahbuddy

I'd vote to get them away from the walls as much as possible. I know in setting mine up I had one channel at about 2' or so from a side wall, and moving that guy to the 3' mark opened up the soundstage substantially. I think ideally you'd want nothing between them either, but mine do and I don't notice any issues so I'm not sure the 'interference' worries from your drawing will come into play. Gotta love the MS Paint layoutd drawing.

Meanwhile, I just put Larry's rings on which allows me to tighten the drivers and passive as hard as I want: air leaks no more! Probably a good route to go if you're looking to get that bass going.

audio_alan

Audioquest wrote: »

OPTION 1: I would move the speakers close to the TV, and put the sub on one side and the audio rack on the other, outside of the speakers. A little closer together is better than right beside the walls. Better yet, move the sub to the other end of the room, and the rack to the side wall out of the way.

OPTION 2: sell them to me!

So option 1 is a vote for "C", and option 2... Hahahaha, funny guy! Not a chance, well at least not until I buy a set of 1.2tl's.

yeahbuddy wrote: »

I'd vote to get them away from the walls as much as possible. I know in setting mine up I had one channel at about 2' or so from a side wall, and moving that guy to the 3' mark opened up the soundstage substantially. I think ideally you'd want nothing between them either, but mine do and I don't notice any issues so I'm not sure the 'interference' worries from your drawing will come into play. Gotta love the MS Paint layoutd drawing.

Meanwhile, I just put Larry's rings on which allows me to tighten the drivers and passive as hard as I want: air leaks no more! Probably a good route to go if you're looking to get that bass going.

Another vote for C, possibly B. Going the B route will definitely give me more floor space...

audio_alan

Good one, Sal! But I doubt I'll be moving any time soon, so until then I'm stuck with the current room. That "room" is actually fairly large though (it opens up into the kitchen and dining room, high valuted ceilings, etc), but the wall that I want them on just isn't as wide as it needs to be. Dang it, didn't the architects know about SDA's!? I suppose I could turn them sidesways onto the longer wall, but the functionality just wouldn't be the same.

Now that's the true definition of an audiophile -- Buys new speakers, has to look for a new house to properly set them up.

ben62670

TOOLFORLIFEFAN wrote: »

Alan,

I would not do that. If I was you I would go with room treatments, and for gods sake SPIKE them, get them off the floor..

IMO rooms that are not that ideal for SDA's room treatments are the only thing to help balance the sound..

Just my .02

Yep. I feel that the 3 foot rule is mostly to prevent the reflections from **** with SDA effect.

audio_alan

Ah ha!!!! I re-read the manual and I think it answered my question. The manual states: "Your speakers will generally sound best when placed close to the back wall. Also, the front baffles should be at least 2 inches foward of any obstructing objects, such as cabinets."

I suppose that doesn't specifically say that it can be buried inside a cabinet or nook, but it suggests that the most critical reflections (that could make or break the SDA effect) occur in front of the cabinet - not on the sides or rear. I take that to mean I can recess them, but have them sticking out 2+" into the room and all should be well.

Doesn't anyone think that the "front baffle" statement is saying something else? Or perhaps personal experience has dictated otherwise?

Thanks again for everyone's input...

Alan
P.S. Yeah, I should probably just try it, but I'd prefer not to rip apart my shelves and find out it's going to sound like dung afterwards...

ben62670

You don't want them tucked in a cubby.

dorokusai

I've yet to hear an SDA in the perfect, manual suggested, setup and every one has always sounded quite good. You need to simply try some different arrangements and pick the one that sounds best, simple. Stop thinking, start doing.

F1nut

but it suggests that the most critical reflections (that could make or break the SDA effect) occur in front of the cabinet - not on the sides or rear.

Nope.

audio_alan

ben62670 wrote: »

You don't want them tucked in a cubby.

Ben - So what does that statement in the manual mean? You can have them in a room, but not in a cubby/cabinet, but next to a cabinet is ok as long as the front baffle is 2" in front of the cabinet? Sounds like splitting hairs to me. Wouldn't the cabinet be somewhat acting as a cubby hole - blocking the side of the cabinet from breathing?

Either way I'm not going to be getting a perfect setup. I'm either going to get them nowhere near 6-8" from the back wall, or they are going to be tucked into the cubby hole. You're suggesting that I should sacrifice bass for the possibility of the sides of the cabinets causing bad reflections that would affect the SDA effect? The manual seems to suggest that only the front 2" matter... <shrug> I'm not trying to be a pain, seriously. I'm trying to figure out the best possible solution for a less-than-optimal room...

I suppose I could actually enclose part of the cubby hole to effectively move the wall forward, thus giving me a solid backing to act as if they were only 6-8" off the back wall.

dorokusai wrote: »

I've yet to hear an SDA in the perfect, manual suggested, setup and every one has always sounded quite good. You need to simply try some different arrangements and pick the one that sounds best, simple. Stop thinking, start doing.

I figure I can spend a day asking questions before I destory my shelves... or not.

ben62670

If you make that cubby flush with the front baffle of the speaker you are essentially making the wall part of the baffle.

audio_alan

But what if the speaker is sticking out of the cubby (at least 2", as the manual suggests), letting the tweeters disperse their sounds without running into walls directly on the left and right (as would happen if it were pushed too far back into a cubby)?

ben62670

Thats better.

audio_alan

ben62670 wrote: »

Thats better.

Ok, that's what I was suggesting... based on what the manual was stating... and as shown in the picture on post #21. Not totally hidden, but let the front baffle breath while still removing most of the speaker from the floor space of the room.

Believe me, the last thing I want to do is make these speakers sound bad. But, if I could reclaim about 3' of floor space, that would be great!

audio_alan

Update - Well, I decided to try shifting some stuff around last night. I moved the sub/equipment rack to the outsides of the room, and moved the SRS's in closer to the TV and back, nearly against the shelves in the nooks. (Basically drawing "C" above")

The good news - Suprisingly, the bass is MUCH stronger now, even though the cabinets are still about 20" from the rear wall. :eek: It took putting my 2.3's about 6-8" from a rear wall to notice that much of an increase in bass, so the nooks must really be helping to reinforce the bass. Hmm, maybe I'd actually end up with too much bass if I recessed them (although removing the shelves would also change the shape and dynamics of the nook).

Now for the bad news - Moving them closer together noticably reduced the width of the soundstage. The SDA effect seemed about the same, just smaller. Perhaps I should move them back out a bit (but still leave them back up against the shelves), and put acoustic treatments at the first reflection points? Then I'd have the extra bass I'm looking for, and a wider soundstage as well.

Maybe I'll follow Sal's advice and go buy a new house...

P.S. As always, thanks to everyone for your insights and advice!

thsmith

Alan, my 1Cs are at least 26" from the back wall and never felt bass was deminished.

I do try to maintain the side wall equal distance and in my case 34" with 2" in front of my Mits 73" rphdtv.

Doubt that helps but thought I would through that out there.

F1nut

It took putting my 2.3's about 6-8" from a rear wall to notice that much of an increase in bass, so the nooks must really be helping to reinforce the bass.

Six to eight inches off the back wall is pretty much the norm for SDA's.

Placing yours in the nooks is basically corner loading.