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Do dipolar surrounds make a difference?

3155 Views 62 Replies 19 Participants Last post by  OneTimeCRX
I'm a relative newcomer to home theater, only really getting into 5.1 sound about 2 years ago. I've already gone through many upgrades, most recently replacing my mains (buying Mission m35i's). I am quite happy with the stereo performance of my system, but I have never been satisfied with the 5.1 aspect. I would like to feel completely immersed in a movie...hear rain all around me, hear things passing behind me...but I feel like I never hear anything from my rears, no matter where I put them. I have tried mounting them high up on the wall, having them directly behind me, and having them at the back wall of the room...with little success. The rear speakers (JBL 2500 bookshelves) sound great on their own when run in 6-channel stereo mode, so this isn't a case of just having crappy speakers. My system is calibrated with a SPL meter so levels aren't the problem.


My question is, would adding a pair of side surround bipoles make much of a difference in my system? My current receiver is only 6.1 so upgrading to 7.1 would involve a receiver upgrade in addition to buying the bipoles, so this would be a rather large investment...I would like to eventually have all of my speakers from the same line, matching my Mission fronts. Mission does make dipole surrounds in my line.


What do people do out there to make a movie a completely immersive experience?
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Man thats a big question this late at night.


You used the words Dipole and Bipole interchangeably. Some dipole speakers have a switch to change them to bipole configuration.


A dipole will mount on the side wall in line with where you sit BUT you have to have space behind you [Pref 6+ft]for them to work properly. At this point you would have 5.1. Add the rear on the back wall and we have 6.1. Depending on the ability of the receiver you may be able to put 2 speakers in parallel on the 6th channel on the rear wall. If the receiver is lower power and can't handle low impedance than wire the 2 in series and turn up the volume to the 6th channel


Ok that said, you may not have your receiver set up properly for the sound field you are trying to use for the material. Reread your manual you may be missing something simple.


Dipoles are really nice and the can enhance the rear effect but you should be doing very well with the JBL's.

Got to be missing something in the set up. After you read the book again call the factory tech.

One thing that can really bring out the rears is put a second sub off of the rear surround speakers using "speaker line in" and then to the L+R rear surrounds. Often a 10" is enough. THe ratio is 2:1 sub : woofer size {R^2X3.14= Area}


Another thing that can effect the experience is room acoustics. If your room is like a cubed ping pong table the sound will be very uncontrollable and one may have a tendency to turn it down to keep it from being painful and then we loss ,depth spaciousness or emersion.


Also consider getting a pink noise set up disk to EQ your set up. Avia is decent. There are some 5.1 set up discs out now . Reeves is one.

The speaker/amp set up is the most tedious and leanthy part but the most rewarding for the $$$ spent. It will give you a better understanding of room acoustic too.


I'm Around if you want to chat more, because a lot of basic questions have to be answered before a solution is found.

Also there are others out here chomping at the bit to add their $0.02 of good wisdom.


Bear!
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bear paws,


I have moved with this system several times and have set it up manually each time. I feel like i've memorized the manual. Its not that the rear speakers are not working in 5-channel mode, i just don't find the rear effects to be that noticeable or immersive.


EQ is the other major thing i'm considering. If I did get a disc like Avia, how would I use the results of my frequency sweeps? My receiver is a Yamaha Rx-V640, it does not have YPAO or any EQ features. Do the newer receivers with auto setup like MCACC and YPAO make much of a difference? I've also considered an eq for my sub like a BFD, but It would be nice to have a receiver that could handle the EQ of frequencies below 60 Hz, which the newer Yamaha's can not.
Have you tryed any sound treatments yet? It may be the last thing to cross you're mind but I can be one of the best improvements you do. I made 4 DIY panels for my room & it made more of an improvement to my sound than anything I have done/tryed before.

I didn't have a problem with hearing my rear surrounds as you describe, but things just never really sounded clear to me. I built the traps & hung them & wow BIG change. Now the surrounds are much more noticeable, detail in all the speakers is much finer & easy to make out. I have noticed things in quite a few movies that I never heard before. Plus the room is much more relaxing now just from the added quietness.


Anyway I'm sure sound traps aren't to the answer to you're problem, but they can be a very big help. I had thought about doing it for years but never thought they could make that much difference. Now I wouldn't go without them for anything, they are by far the best improvement (tweak) I have ever done.
Quote:
Originally Posted by lazyhaze
I feel like I never hear anything from my rears, no matter where I put them
Try raising the volume of the surrounds speakers until you feel you can hear them better. You won't harm anything and can always return to calibrated levels if you want to afterwards.


Sanjay
Quote:
Originally Posted by sdurani
Try raising the volume of the surrounds speakers until you feel you can hear them better. You won't harm anything and can always return to calibrated levels if you want to afterwards.


Sanjay
yeah, if you can't hear them, turn the surrounds up or turn the mains down and the master up.
I am not familiar with the Yami 640. Or any Yami for that fact.

But I find it difficult to belive that any modern day receiver would not have some means of adjusting the HIGHs, TREBLE, and BASS. frequencies for each channel. Now this is not super EQ as in a BFD or other multi freq. EQ controllers but unless you really are into this stuff I find that basic set ups are more than adequate.


Sonytheater is correct{read my above post paragraph #5 on acoustics} Re "cubed ping pong room".

All too often we blame the equipment when its really the room and the fix is a hell of a lot cheaper. THe volume level may appear to be too high and annoying but its actually ricoshaying around in there and causeing a din.


Take a run up to Rives Audio web site and look at their downloadable graph for plotting Freq. response. They do a pretty good job of explaining it. All you need is the RS SPL meter or equiv.


Also at the beginning of this AVS section "speakers" there is a "sticky" called Whats the big deal about crossovers. There are a few links in there that are really good.


Sanjay and Hyper have valid points about raising the volume as long as the room is tame to some degree. Equal speaker output is a starting point or as some Tecnos call it reference.


IMHO EQing is a bandaid, a poor one at that, to cover up some another problem like acoustics or speaker deficienties.


AS a side note; I have always used, with great success, the 2:1 rule. Meaning when you go up to the next speaker size in the chain, go up by no more than twice the cone area of the previous one. Unless you use VERY expensive drivers, this method eliminates HOLES in the sound field and gives smoooooth transitions.


Bear!
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This is neat tech stuff, this r^2 x 3.14 = area thing aka 2:1 rule, but my feeble mind needs help. Please explain.


Is this why my B & W 12" sw (750) matches my 703's in front and the ds7's on the sides?


Perhaps this is what speaker OEM's do for you when you buy speakers in a standard producct set-up as oppose to mismatching with a buy/build as you can approach.
Norm


Nah, its not tech stuff, just a method or formula I found that works good without breaking the bank.


Lets say you have a mid range driver/speaker that is 6" and you want to add to that a larger driver like a woofer to lower the range father. 6/2=3^2=9x3.14=28sq inchs of driver area. The next driver up in size should not be greater than approx. 56sq inches in area. So a 8" woofer [50.24sq"] would be the next driver in the chain up. Than a 12" =113sq".


Now there are crossover freq. that have to be worked into this also to round out the package/speaker.


This method keeps the drivers from being driven into distortion, a narrower response band thus less black sound holes and you can use less expensive drivers because they don't need to reach for the extremes.


Help?


Bear!


Like all man made rules they are to be broken on occassion.


Yes on your edit.
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thanks
10-4


Bear!
My Yamaha does have a treble and and a bass knob, but you can't apply that individually to each channel. I don't believe that raising the volume on my rears is a solution because they are already calibrated with a SPL meter from my normal sitting position...and they sound too loud if I boost them and then listen to music in 6-channel stereo mode, which is what i use my system for 80% of the time. As Sanjay suggested I could boost them for a movie and then return them to normal. but I would prefer to have a solution that doesn't require repeated tinkering.


Room treatments are interesting, although I admit I know nothing about them. I am a student and move frequently, so I have to deal with a different room setup every time I move.


I know how to plot a frequency response graph, I am in electrical engineering. But again I have the problem with what to do with this information...I can't give any of that information to my receiver.


I watched a movie again last night and noticed the usual problems...i even experimented with turning the rears off during the movie and it didn't make much of a difference. I wish more DVD's were mixed in DTS as from my experience DTS tends to utilize the rear channels more.
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Please excuse my ignorance of your reciever but;


When you play a movie thru the Yamaha is it really in 6.1 "dts" or is the reciever in a neo6.1 mod. Neo meaning emulated, which would really be sterio. Is there some indication that the reciever is receiveing or in DTS mod, like a light/led on.


Second, is the DVD set up really outputing DTS. Or is it combineing all the tracks into sterio, due to wrong set up or even out put jacks. What are you useing for interconnects. Digital coax , toslink, ??? No disrespect ment but I have to get this clear in my mind.


Bear!
lazyhaze,


When I read your words " ... I have never been satisfied with the 5.1 aspect. I would like to feel completely immersed in a movie...hear rain all around me, hear things passing behind me...but I feel like I never hear anything from my rears ... ", it was like deja vu all over again when I had a 5.1 speaker set up. I was not satisfied with the surround envelopment.


I then added two rear speakers to expand to 7.1, using Logic 7 to generate 7.1 "discrete" outputs from various input sources, and the surround envelopment was significantly improved. It made a big difference in my system.


My suggestion is to go to a 7.1 set up and trade your receiver in for one with DPLIIx and/or Logic 7.


Bruce
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I'm guessing that you live in an apartment and that your HT room is open to the kitchen and a hallway. You're never going to get that immersed feeling out of a big open room like that. There are so many things wrong, but start with the fact that surround sound needs walls to bounce off of, especially diapoles. That is why 7.1 can be more effect. There is less need to bounce the sound around and more direct surround sound.
----K---


Even at that he at least should be hearing diff channels and I'm not certain thats the case.


Bear!
My home theater is in my bedroom in a 10x20 rectangular room in the basement of a house. It looks somewhat like this:


*RR**Desk**RL*







------Futon------




*MR***C***ML*



My listening position is a futon approximately half way between them. It should theoretically be a good setup, as I have lots of space behind my sitting position to get a sense of space.


bear paws, I am hearing different channels. My Yamaha amp displays the number of channels it is receiving, with a little symbol for each received channel. It also automatically chooses the correct decoding with a DTS or Dolby signal. I have a coaxial connection from my computer, and an optical connection from my DVD player. If I have a two channel source like music I can select Neo:6 but that is not my concern. I am quite familiar with audio hardware and setup, I work in the production studio at a radio station.


-BruceOmega

I've tried experimenting with the various DSP options in the Yamaha but they haven't really made much of a difference. Is Logic 7 really a big improvement?
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I'm lost. :(
From his description, it really isn't clear what he is hearing and isn't or if maybe his expectations are too high for the mismatch speakers and poor room that he has.


I agree with you that it sounds like something isn't set up right: like the DVD player is sending 2-channel and the receiver is using pro-logic to fill in the surround. One thing I find odd is that he claims he can't turn up the rear channels, because then music is too loud. This sounds like pro-logic to me. The receiver should be set to Dolby Digital mode for DVDs and to Stereo mode for music. All mid-level receivers that I've delt with allow you to have differnt channel settings for the differnt modes. He should be able to boost the rears in Dolby Digital mode to a good level, but leave them at the balanced level for the Stereo mode and never have to switch.


If everything is setup correctly, I think he just has too high of hopes for his room. A big open floor plan just won't give that immersed fealing.
Quote:
Originally Posted by lazyhaze
My home theater is in my bedroom in a 10x20 rectangular room in the basement of a house. It looks somewhat like this:
Do you have walls on both sides of the room?
Quote:
It should theoretically be a good setup, as I have lots of space behind my sitting position to get a sense of space.
Our human hearing gets its sense of space from lateral (sideways moving) sound. The best and easiest way to stimulate these spatial cues is with speakers placed along your sides. Is this possible with your room?
Quote:
-BruceOmega

I've tried experimenting with the various DSP options in the Yamaha but they haven't really made much of a difference. Is Logic 7 really a big improvement?
Not to speak for Bruce, but I don't think it's so much about LOGIC7 as it is about the advantages of a 7.1-speaker set-up over a 5.1 layout. If you don't have L7, you can get excellent 7.1-channel processing from Dolby Pro Logic IIx.


Sanjay
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