Strange sda placement.....

naturallight

I pulled the SDA 1C's out of the back room, just to test them. I did not think too much about placement just put them inbetween the 12's, about a foot off the back wall.

To my utter surprise, I had massive bass, the SDA "effect" was flying around the room..it was fantastic.

Now yesterday, i pulled the 12's out of the space, moved the SDA's wider apart, thinking they were great before now there going to be better......



Well..again to my surprise..that was not the case. The SDA "effect" seemed to diminish, and maybe a little lose on the bass, but was for sure not the same sound i had.



The problem is that now the left SDA is like over 3 feet from the sidewall, (due to the door)while the other is about 1 1/2 feet from the sidewall.



Now as "insane" as this sounds. They sounded better put in between the 12's.



The only thing i can figure here, is the 12's are taller and longer then the SDA's The SDA's were sitting about 1 foot from the 12's, and a tad back from the front of the 12's. The 12's are really acting like sidewalls for the SDA's...



Now you may say i'm nuts...in fact i would say i'm nuts..but the sound difference between the 2 setups...is not small. Pretty much anybody could tell the difference.



I'm going to move the SDA's back to about the position they were at before, when the 12's were in place.

The 1 foot off the back wall, from the back of the cab, is really were the SDA's like to be. If you move them farther out in the room, you start missing the bottom end. I get the strange feeling the SDA "effect" is not going to improve, as i'm really now moving them father away from the side walls.



Now again, i know that the SDA placement is always something that you need to play with to get the best sound out of them. But the sound with them stuck between the 12's was in a word fantastic, i could not believe my ears...now, without the 12's in place..well it's ok. Yes you can call me nuts..I wish someone was here to HEAR the difference...it's kind of the strangest thing i have ever heard..

oldmodman

Over the years I have discovered that speakers sound best wherever they sound best.
It might not be where your eyes think they should be, and it's almost never where the significant other wants them.
Just be glad that they don't sound best while blocking the doorway or the refrigerator.

naturallight

I have had these SDA 1C's since new in 1987. I have always tried to put them in the "right" space as far as sidewalls and stuff. For the most part, i got them to work.



I just took them from a back room, thru them in between a set of 12's just to test them. The sound from them was amazing...it was like what are you out of your mind putting these in the back room...LOL

The "SDA" sound was there full on..so was the bass. This is for 25 year old speakers!!!!



I sit 15 feet back in this room...the SDA sound was amazing.



I never stick one set of speakers in between another set...It's just because these thing are not easy to move.

BUT the sound was fantastic.....this was only a test...but it was great.



I managed to move the 12's out of the way..move the SDA's Little father apart. The sound difference is not little..it's alot. You would pretty much have to have hearing damage NOT to hear the difference.



Before..If you know what SDA's sound like..these were like the best SDA sound you could get. NOW....at least 50% of that sound is gone. Now maybe moving the SDA's a foot on each side..well maybe. But i sit 15 feet back in the room. I just don't see that much loss in what the speakers can put out.



I just have no real explanation for the sound loss, or why it sounded so good stuck between the 12's

F1nut

Are your speakers 15 feet apart? If not, you are sitting way too far back. With SDA's, you need to sit back the same distance as they are apart.

yeahbuddy

Maybe what you've discovered is that everyone's been throwing their money away on expensive upgrades/mods on their SDA's all these years when really all anyone needs is a pair of 12's to sandwich their speakers between and BOOM! Instant SDA bliss.

naturallight

No F1..thats the kick. Now i have not measuered how far i really sit away..but at min..it has to be 13 feet at least.

The SDA's when stuck between the 12's were no more then 8 feet apart..and they sounded great. Now why..i have no clue. Why they sound worse if you take the 12's away and move the speakers wider apart..again i have no clue.

Maybe like i said, the 12's acted like sidewalls for the SDA's...and whatever is going on in MY room..makes them sound better...is beyound me.

Pretty much i have no answers or understand why they sound better put next to the 12's. I'm pretty much just telling you what i heard..for better or worse.

brgman

Cables.
It must be the cables.

naturallight

I did not post this to debate about anything, nor have stupid comments made about cables or anything else.

I posted this as, i really don't understand why this can happen. But my guess is probably correct.(for lack of any others) That the 12's being taller and wider then the SDA's act as sidewalls for the SDA's since they sit a bit back from the front of the 12's. So some how..(in MY room)your getting massive SDA sound out of this insane setup i have no clue. I'm not saying anything else or really know why this should happen. Just stateing what i heard....nothing more

brgman

Great just what we need in the world.Another miserable,humorless soul.

pitdogg2

brgman wrote: »

Great just what we need in the world.Another miserable,humorless soul.

You call:evil::evil:(insert evil laugh)

naturallight

No..your right...It is a funny comment..sorry...

DarqueKnight

naturallight wrote: »

I pulled the SDA 1C's out of the back room, just to test them. I did not think too much about placement just put them inbetween the 12's, about a foot off the back wall.

To my utter surprise, I had massive bass, the SDA "effect" was flying around the room..it was fantastic.

naturallight wrote: »

I just have no real explanation for the sound loss, or why it sounded so good stuck between the 12's

The 12's are acting as giant passive radiators for the 1C's, reinforcing the sound. The 12's are roughly the same size as the 1C's, have the same number of drivers, have identical driver and passive radiator sizes and have identical driver and passive radiator arrangement.

It is usually a bad idea to have other speakers in the same room because the cone vibrations of the inactive speakers typically muddies the sound of the active speakers. In your case, with inactive speakers close in size and configuration to the actives, you achieved some pleasant sound reinforcement.

During critical listening, you might notice a decrease in midrange detail although the bass and SDA effect is enhanced.

naturallight

well Knight..maybe your right.. I went down and moved the SDA's back to were they were as if the 12's were there. They sounded better.

I went and took measurements. My seat is 14 feet from the front of the speakers. I moved the SDA's closer together...they are only 7+ feet apart...which should say this should not work right..but it dose. They do sound better in that position.



At that point, i said what the hell..tried to move the 12's back into the same position they were in before..not an easy task since these speakers are dam heavy...LOL



Now since the 12's are forward of the SDA's..as far as the front goes..you would think this will really screw up the SDA's and not sound good. But again..i have to say..this is not the case. I tried this out with mostly CSN stuff.



Again..I have no clue why this works..maybe it's just a funnel for the SDA's..but I'm sitting 14 feet back..and, man...you sure get the SDA effect. Maybe i'm willing to say the sound with the 12's in place is not better, as i've been listening for too long, and drinking to much at this point...LOL But the stupid fact is they should sound worse..which they do not..at all. To be honest..they sound great..sit there with your eyes closed and just get with the music..there is really no fault here.



Now why any of this works..beats the hell out of me....it should not..at least according to the stock SDA placement stuff.


I am for sure not going to tell anybody this works for them...I'm not sure why it works in MY basement..but this is what i found out for ME..in MY basement, with MY speakers...thats all i can say

GlennDog

Well descibed . . . B4 and After Pix, please . . . ty

Moose68Bash

naturallight, Your experience is very interesting. I recently moved my 1Cs to my exercise/physical therapy room in my basement to make way for the SRS 1.2s I bought for the family room system. In the basement, the 1Cs sounded as good or better than they ever did in my family room. I was surprised, because my basement is not an optimal space for listening.

When I replaced the SL2000 tweeters with RD0194s, the performance of the 1Cs improved even more.

I write this because I placed a pair of vintage Allison 6 speakers that I use with the television in the basement on top of the 1Cs. I will now have to remove the Allisons to see whether they are acting as not-so-giant "passive radiators," as DarqueKnight suggests your 12s were.

yeahbuddy

naturallight wrote: »

I posted this as, i really don't understand why this can happen. But my guess is probably correct.(for lack of any others) That the 12's being taller and wider then the SDA's act as sidewalls for the SDA's since they sit a bit back from the front of the 12's. So some how..(in MY room)your getting massive SDA sound out of this insane setup i have no clue. I'm not saying anything else or really know why this should happen. Just stateing what i heard....nothing more

Regarding the 12's-as-sidewalls theory, I'm not certain that jives with my understanding of the SDA effect, though I'd certainly defer to someone like DK for a more expert opinion. I always thought that SDA's don't like being close to walls due to the fact that reflective effects from sidewalls destructively act against what the SDA's are trying to do: cancel crosstalk. This is also why SDA technology in Polk's surround soundbars is more effective than many soundbar manufacturers that rely on reflective walls to "bounce" the surround signal to the listener's ears, but the Polk soundbar functions well regardless of room geometry because the SDA effect is utilized.

Which makes me lean towards DK's theory as more plausible...also leads me to think that I should get rid of the extra speakers I have laying around the living room that might be passively radiating me out of better sound.

rooftop59

DarqueKnight wrote: »

The 12's are acting as giant passive radiators for the 1C's, reinforcing the sound. The 12's are roughly the same size as the 1C's, have the same number of drivers, have identical driver and passive radiator sizes and have identical driver and passive radiator arrangement.

It is usually a bad idea to have other speakers in the same room because the cone vibrations of the inactive speakers typically muddies the sound of the active speakers. In your case, with inactive speakers close in size and configuration to the actives, you achieved some pleasant sound reinforcement.

During critical listening, you might notice a decrease in midrange detail although the bass and SDA effect is enhanced.

Just for the record, I think that the OP is referring to RTi12s, not Monitor 12s. This might make a difference to this theory. Other than that I have nothing to contribute here

Mr. Bubbles

I would tend to agree with DK on his points here, Though I'm not sure that is all that is going on here. Generally speaking you would not want additional speakers in the same room as they will vibrate and passively add to the sounds you hear. In this case the drivers, etc are so close to matching and listening position/ speaker placement/ passive speaker placement, are all lining up to give a pleasant reinforcement.

As for the 12's acting like walls for the reinforcement, that is not very likely but possible. If the cabinets are side by side it is not likely that the "wall" would be large enough to allow for pleasant reflections and still allow the SDA to be spread out enough. However walls can reinforce the SDA effect in some cases. The very first pair of SDA's I ever heard were in a guys basement and closer to the wall on the left side than on the right by a pretty large margin. When auditioning the speakers, i could distinctly hear locations along that wall that sounded like more speakers. This was not the case on the right side. Since I started owning SDA's i have played with placement with that memory in mind and find that most times the SDA effect will be pronounced along a wall within a couple of feet to the side of the speaker and not quite as distinctly positioned when farther away. This does 2 things; it emphasizes the wide sound-stage of the SDA's but also limits it's natural sound as many sounds become much more focused even though they are beyond the sides of the speaker cabinets.

A good thing to keep in mind is that not just speakers create passive radiators. i have much more trouble with the "decor" items that my wife likes to place through the listening space. Many arguments ensue as items disappear. One of my 2 ch rigs is in the main family room along with the HT rig. Since the SRS's do not please me in a 5.1 set up, they are in the room with many other speakers. I have performed listening tests with and without all of the other speakers and can hear hardly any difference. I am sure measured data would indicate more negative response than I am hearing.

yeahbuddy

Seems like this is the setup he's talking about, RTi12's like rooftop mentioned.

DarqueKnight

rooftop59 wrote: »

Just for the record, I think that the OP is referring to RTi12s, not Monitor 12s. This might make a difference to this theory. Other than that I have nothing to contribute here

yeahbuddy wrote: »

Seems like this is the setup he's talking about, RTi12's like rooftop mentioned.

OK. Thanks for the clarification. I think the passive radiator theory is still plausible with the RTi12's.

naturallight

This is the setup. Yes the speakers are RTi12's. Now i did measure my seating position, it is 14 feet away. Now the pic may not look it but the SDA's are about 1 foot away from the 12's, and sitting 1 foot off the back wall, measured from the back of the SDA cab. The 12's are so long that even with the SDA's a foot off the back wall, the 12's still stick out some in front of the SDA's , plus there taller. Hence my theory as the 12's acting like sidewalls to some extent. Why this works..have no idea.



When i took the 12's away, put the SDA's in were the 12's were. The SDA "effect" really went down the tubes. To place the SDA's in the "supposed" right position, for the seat distance, the one speaker would be sitting in the doorway. I went and moved them back to the position you see in the pic, "without" the 12's in place.....the SDA effect was much better. Now how much better with the 12's put back in place, as the pic shows..thats up for debate. Now when i first put them in that position, i had not heard these speakers in well over a year...so the SDA "effect" was blowing my mind..it sounded great. Now that i have gotten more used to the sound again, with the 12's in place...may not be THAT much better. But there still is a difference.


why ANY of this works, when it really should NOT....I have no idea and can't tell you.

If there are any Polk SDA guys that live close to Atlanta ,GA and would like to hear these...please feel free to email me.

yeahbuddy

I wonder if you just turn the RTi12's around you'll get the same effect. You'll still have the RTi "side walls" in place so if that's the cause then the effect will still be pronounced. I realize that the passive radiation would still be present but it won't be emanating straight from the front to the listener, so you'll experience any radiative effects as reflections and likely out-of-phase. Might notice a stark difference that way if DK's theory is correct.

GospelTruth

I thought that SDAs were supposed to be 2-3 feet away from any side wall as well. From your picture, they would be almost next to the wall if you placed them where the RTi12s currently are. I know that they might be the right distance apart relative to your listening position, but maybe the distance apart to your listening position isn't as important as the distance the SDAs are from the sidewalls. My thoughts anyway on why they sound better in their current position with or without the RTi12s next to them than they do where they are closer to the sidewalls. I'm sure some of the veteran folks here can comment about what is more important - seating distance vs. sidewall distance.

You could always get dining room chair or the like and move it closer to the speakers to see if moving the seating position closer helps with the SDA effect. I know I've done that myself to see if the effect is better in other seating positions based on the current speaker placement. Just a thought. As always, speaker placement becomes something of a tradeoff given your seating position and the room design.

naturallight

Well you can't go by the pic...it's deceiving. The 12's are well over a foot off the sidewall.



I don't remember what the "supposed" SDA placement should have been at this point. Somebody said if you sit back 15 feet, then the SDA's should be 15feet apart.

That i can't do as they would be sitting in the doorway. Now i'm sitting 14 feet back, and the SDA's are really only 7 feet apart in that pic. YET.....your getting full on SDA sound..and plenty of bass. Pretty much your not missing anything. So to move my seating position more up front...would seem worthless at this point.



Why it works..don't have a clue, but i would have to say..just don't go by stock setups. Every room is different, and you have to move the speakers around in different placements to get the best sound.

Nothing more, I am for sure not telling anybody to do this.....this is just what i hear in MY basement. Nothing more.



The other insane deal hear is the amps. Now what your looking at in the rack..the bottom amp is an Onkyo M-504 power amp. What you see in the second rack up is a QSC M5 500watts per. It uses an Class H series power set up. It is a pro amp.



Now why is it in there. People on here were debating on this pro VS "high-end" amp. SO...I just thru it in there, to try out the 12's. On the the 12's...was not a pleasant amp. It made the 12's too bright for my liking..but then again people say the 12's are too bright for 2 channel music.

The Onkyo is a warm amp..which works fine for the 12's in my 2 channel system...there not overly bright.



Now when i put the SDA's out there....I had the QSC amp hooked up..so saw no reason to mess with it, and just pulled the banana plugs from the 12's to the SDA's. It was only a test....



To MY surprise..again..the SDA's did not seem to mind this amp at all. They sounded great. At least at first hearing. Now i went and put back the Onkyo on the SDA's.....but really. I'm not hearing a major Difference.

At least at this point. I would have to go back....now that im used to the SDA sound..and switch the amps back and forth to really give a good answer on that. Again..nobody go nuts on me....this was just a test in the first place.....right now i would have to sit and listen to both amps....since i'm used to the SDA sound again. I'm not saying it's right or wrong.....I'm just telling you what i heard at the time. Nothing more, and again only MY opinion....nothing more guys..

naturallight

Let me recap all this, so everybody..including myself..LOL has a some what clear picture.

First off, this is a below ground basement, there are no windows. The room size is 17X 28. The red carpet is very, very thin. It's just covering the cement floor. There is a dropped ceiling about 7 1/2 feet high with heavy acoustical panels in it. There are no pic's or anything on the walls. The back of the room has a big bar, a few seats, and a 1/2 height beer fridge. But this is behind my 14 foot seating position.



Let me state that i'm 60 years old with a bad back. So moving speakers around is really hard. The RTi12's are a real pain to move at all. The SDA's are not that bad to move. There studio models, the MDF feet were broken off a while back, so i just took them off completely, so they sit flat on the floor. So there just easy-er to "slide" on the floor.



Now..the 12's work pretty well sitting in the place the pic shows. They are not angled in or anything, just fireing strait ahead. The QSC amp i had sitting around from a recording project, that did not work out. So the amp was never used. When the discussion came up about PRO amps VS "HI-FI" amps, i said what the heck, i have the amp sitting here why not try it out. The 12's did not like the amp. More to the point, it made the 12's too bright for my taste. Or at least for extended listening. The Onkyo M-504 is a much warmer amp, and with the 12's, i don't feel there too bright.



Now when i pulled the SDA's out of the back room, i was really just making sure they still worked, and was thinking about selling them. So placement was not a big thing. SO, i just stuck them next to the 12's as shown in the pic. The QSC amp was still hooked up, so no reason to change it at that point, so i just moved the Banana plugs from the 12's to the SDA's.



Now, what i heard, blew me away. I was like a dear in the headlights. It was kind of like walking into a Polk demo room back in 1987 and having your jaw drop to the floor. SDA stuff was flying all around the room.

I left that setup like it was for a few days, thinking this can't be right, these speakers are 25years old..Plus in a position that they should not work right in..i must be going deaf or something. Yet..they still sounded great the next 2 days, every time i tried them out.



So in my ultimate wisdom, i said...let me get the 12's out of the way, move the SDA's wider apart.

So i got the 12's as far out of the way, as i could manage, I also disconnected the QSC and reconnected the M-504..moved the SDA's to the position the 12's were in. About as far apart as i can get them in the room.



What i heard, after all that work..was not good at all. The SDA "effect" was really screwed up, for lack of better words. I sat there in utter disbelief, I know what i heard before, how can they be that bad.



I went and moved the SDA's back to the position they were, when the 12's were in place.....WHAM...back came the SDA effect..which means the SDA's are only about 7 feet apart at that point.

Again, i'm sitting there scratching my head. The SDA's should not really work in that position, relative to my seating position.



I have no answer for this, and would never tell anybody to do this. But for some reason, in my room..they work..and work dam well.

At that point i just threw up my hands, struggled to get the 12's back into about the position they were before, as i just could not leave them sitting jammed up against the walls.



Do the 12's sitting next to the SDA's help the sound.....at this point i'm not sure, but they don't hurt the sound at all. WHY....I have no clue. Again..it should not work like this.



Dose the QSC amp really sound that good. I'm not really sure. I was so taken back by the SDA sound stage, that there was no real.."critical Listening" going on.


Problem 1. I made to many changes at 1 time. Problem 2 is i really didn't get completely used to the SDA sound stage again, before i made the changes. Going from 12's to SDA 1C's is pretty much night and day.


I'd really like to test this out more, but i just can't move these speakers around, and get behind the rack every time to make changes. The only way i could do this would be to buy some extra speaker cables, pre wire all this in one shot, so i don't have to move the speakers every time.

TennMan

naturallight wrote: »

... I'd really like to test this out more, but i just can't move these speakers around, and get behind the rack every time to make changes. The only way i could do this would be to buy some extra speaker cables, pre wire all this in one shot, so i don't have to move the speakers every time.

Looks to me like your choices are clear.

1. Quit doing tests to try to prove SDA speakers sound better with non-powered speakers sitting beside them.
2. Buy more speaker wire and do more tests to try to prove SDA speakers sound better with non-powered speakers sitting beside them.
3. Go back to doing tests to prove the earth is really flat even though common sense says it's not.
4. Move the 1/2 height beer fridge right beside your listening chair.

:arrow: I recommend #4.

After 3 or 4 beers your back will feel better and your speakers will sound better too.

-

teekay0007

^^ +1

Also, find a neighbor kid, you know, the one who's always looking to mow your lawn or do odd jobs for a few extra dollars. Get him to help you with your listening/testing sessions and have him do the heavy lifting/moving and changing of speakers and cables.

And get those 1Cs onto some spikes, up off the floor. You'd be surprised at the difference that will make!

naturallight

LMAO..well TennMan.....yeah I like your #4 idea..LOL Really there is no need for me to prove or disprove why the SDA's work in the setup they do. I should really just sit back and enjoy. I'm sure this has something to do with my basement which would be useless to anybody else. So to break whats left of my back it figure it out..pretty useless.



The one thing i did find out, after getting used to the SDA sound again. (just today)...yes the SL2000's have to go.

There passable with Steely Dan stuff, but if you put on Rush, which has a lot of treble..man Getty's voice can cut you a new one. Even with the Onkyo, and the Jolida....it's not good.



So these have to go...the RDO's have to be put in. No matter how great the SDA "effect " is man Rush....can make you a NOT happy camper with the SL2000's that are 25 years old...