Surrounds for HT+audio setup - Jamo (timbre matched) or Polk (flexible)? - AVS Forum
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post #1 of 7 Old 01-08-2013, 10:59 PM - Thread Starter
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I'm new to decent audio systems and I'm in the process of speccing up a new (and my first) 5.1 HT audio system (display to come later). I've done some reading and I'm probably learning enough to be dangerous. After auditioning a number of speakers including some from Klipsch, Mission and B&W, I finally met a pair of Jamo C607s which made (not just) my ears prick up.

These will be assisted by a Jamo C60CEN centre speaker and driven by a Marantz SR5007 or SR6007. A REL T-7 or T-9 will help round out the lower frequencies.

System usage will probably be 80% movies 20% 2ch music but who knows how that will change once it's in.

The room is 4.8x5.2m (16x17') with concrete rendered brick walls and a concrete ceiling. Ceiling height is about 2.4m.

I can't mount the speakers to the immediate left and right of the seating position due to a large sliding door in the way on the right hand side, unless I mount them far above ear level pretty much touching the ceiling. (there's a bit of space above the door)
On the left hand side, the wall is about 1.5m further away so I am hoping Audyssey's time correction can help with this. Use of a stand (other than against the wall) or ceiling hanging arrangement would not be very practical.

For the surrounds I am tossing up between Jamo C60SUR dipoles and Polk FXi A4's which can operate in either dipole or bipole mode for flexible placement. The FXi A6's would be great but they are huge. I'm looking for a dispersed sound, not a directed one so would prefer to avoid direct radiating speakers (I think).

My feeling is that the FXi A4's seem like the 'safer' option. They will provide more flexible placement options - whichever works best sonically in this room:

* to the sides but 0.3-1m behind listening area in bipole mode
* on the back wall in bipole mode
* at ceiling height directly to the sides of the listening area in dipole mode

But - the Jamo C60SUR's get good reviews, have two midrange drivers and would be well timbre matched - but it seems that in my scenario, there's a risk they'll sound less than ideal at ceiling height and if I mount them lower, further back on the side wall, the listening space will likely be outside the dipole null.

What would you do given these two options?
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post #2 of 7 Old 01-09-2013, 04:49 PM - Thread Starter
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Maybe I should be more succinct. In short - how critical is placement of dipole speakers? Is placement on the side wall a metre or a little more behind the listening position an issue (meaning the listener will likely be outside the speaker's real null)?

If so, are they likely to perform OK at height and do they need some breathing room between them and the ceiling?

Also is placement of the side left speaker about 1.5m further out from the middle seating position going to pose much of an issue?

Any input appreciated.
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post #3 of 7 Old 01-09-2013, 04:59 PM
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... In short - how critical is placement of dipole speakers? Is placement on the side wall a metre or a little more behind the listening position an issue (meaning the listener will likely be outside the speaker's real null)?
A meter or a little more behind the listening position puts them almost within the arc of rear surrounds in a 5.1 set-up, and means that you'd essentially have one face acting as a direct-firing speaker. IMO, you should consider a good pair of bookshelf speakers for surrounds (if you haven't done so already).
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If so, are they likely to perform OK at height and do they need some breathing room between them and the ceiling?

Also is placement of the side left speaker about 1.5m further out from the middle seating position going to pose much of an issue?
Audyssey should be able to adjust EQ, distance and level settings to compensate.
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post #4 of 7 Old 01-09-2013, 08:56 PM - Thread Starter
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Thanks for the feedback Eljay.
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Originally Posted by eljaycanuck View Post

A meter or a little more behind the listening position puts them almost within the arc of rear surrounds in a 5.1 set-up, and means that you'd essentially have one face acting as a direct-firing speaker.

Yeah. According to the C60 owner manual the dipoles should be within a 20 degree arc of the immediate side position, so unless they're right up at ceiling height they would have to be further back as you say - in the orange positions on the attached dodgy room sketch.
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Originally Posted by eljaycanuck View Post

IMO, you should consider a good pair of bookshelf speakers for surrounds (if you haven't done so already). Audyssey should be able to adjust EQ, distance and level settings to compensate.

I have considered wall (or stand) mounted bookshelf speakers and it'd be easy to get matching Jamo's but I'm concerned about the directionality of the sound especially due to the small distance from ear to speaker. Maybe some of this could be mitigated by careful aiming; I'm not sure. It seems to me that dipoles or bipoles will be better for a diffuse sound field in this room, but direct firing monopoles would have obvious benefits if I move into multichannel music. In all honesty I think I won't know until I try it.

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post #5 of 7 Old 01-10-2013, 06:38 AM
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Seeing the diagram, I'd start with a 5.1 system, with direct-firing bookshelf speakers placed on stands (or wall-mounted) where the orange dots are. If you really feel that you're not getting a sufficiently immersive experience, you can always reconfigure your system for 7.1 and add bi-/di-pole side-surrounds.

Directionality shouldn't be an issue with the right rear speaker given that i) the bulk of the content comes from the front three speakers and ii) Audyssey should match the levels of the surrounds (raise the left, lower the right) to give you balanced output in back. (And you can always tweak to taste afterwards.)
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post #6 of 7 Old 01-11-2013, 07:31 PM - Thread Starter
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I appreciate the input Eljay. I agree with the logic of what you're saying.

I went down to the store and had a good discussion with the owner about it; long story short I've laid down the cash on the system with the Polk switchable bipole/dipoles. There's a shorter lead time on them than the Jamo C601's which I was considering as direct firing puppies. If I don't like the match of the Polks against the rest of the Jamo's, I can return the Polks and change them out for C601's within the first couple of weeks.
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post #7 of 7 Old 06-20-2014, 03:21 PM
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hi segmentor,

Where did you end up mounting your C60SUR speakers? I'm working on finalizing my mounting spots for them now. I am currently planning to place them between 90-110 degrees from listening position as my seating may move forward/backward within about a foot or so. Are you happy with their placement?
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