Help me design my home theater - planning stage - Page 4

Yes with regard to the Onkyo.

The Denon 4311 has XT32 and can do all 11 channels. Frankly, I don't care very much about the THX certification. I have a video processor which is THX-certified and it was defective from the very beginning.

By the way, I've gone through your thread and I've noticed that you plan to paint your walls a dark burgundy. I think that's fine, provided that the area directly around your screen should have a neutral color or, even better, black. My walls are dark burgundy and my ceiling is wood. I decided to change the color of the walls and ceiling around the screen to black. The improvement in the apparent contrast ratio was pretty substantial.

Mark

"Reference level" is, in layman's terms, just plain LOUD - that refers to the power amp and not the preamp. The best way to achieve that is through an external power amp. Your room is big but it's not that big in terms of volume. Your speakers are reasonably efficient and you say that you don't listen at very loud levels anyhow. Therefore, you should have no problem with your Emotiva. Furthermore, make sure that your speakers are set to "Small" with a crossover of typically 80 Hz or higher. This will send the heavy bass signals to the subwoofer and increase the headroom for your other speakers.

Regarding Height speakers, I fully agree with you not to punch holes in the ceiling. However, you might still want to experiment with Height speakers on the wall, just as high as they can go. Borrow some speakers and then try it out with a temporary rig. If you don't like it, all you've lost is the cost of some conduits.

Mark

(****I will preface my comments by stating this is for informational purposes only, that one can achieve stellar performance *without* THX certification, and that THX certification is not required to have an excellent sounding HT. I am not recommending THX to you, nor do I want your thread to devolve into a debate about the relative merits of THX certification, which can certainly happen very quickly on this forum.)

With the above preface, if one is using THX certified speakers, one could consider THX certification of the receiver or pre/pro for several reasons:

1. To be certain of having the capability to achieve "Reference Level" in the specifically sized room, and at the specific listening distances described in the THX spec. For THX Ultra2, that means 85 dB average levels with 20 dB of headroom:
http://www.thx.com/consumer/thx-tech...ference-level/
in a room of 3,000 cubic feet and at a listening distance of 12 feet.
http://www.thx.com/consumer/home-ent...ce-categories/
Your room is bigger than that, and your listening distances will be greater than that, so THX RL may not quite be achievable in your system. However, RL is *very* loud, and few people can listen at full RL for extended periods. I usually listen at -6 to -8 dB below RL.

2. To be able to mate THX speakers and subs with the THX crossover. The speakers, subs and the crossover work as a system. When the "system" is design from the start to work together, the ideal crossover can be achieved. The THX crossover is designed specifically to work with the roll-off characteristics of THX speakers. The result is the ideal Linkwitz-Riley, dual 4th order crossover, which is free from phase shift. Many non-THX receivers use the same crossover points and slopes as the THX crossover. However, it is not *required* in a non-THX receiver/pre/pro.

3. To be able to use the THX processing modes. Some people find benefit in the THX processing modes:
http://www.thx.com/consumer/thx-tech...iver-features/
These processing modes are only available in THX certified receivers or pre/pros.

THX is a certification process which enables the consumer to be assured that the product carrying the certification meets a specific set of performance criteria, and that any THX certified product will work with any other THX certified product to achieve the prescribed levels of performance. Whether it has value to any one consumer is up to that consumer.

Again, it is certainly *possible* to put together a non-THX system that performs as well or better than a THX system. It's just up to the consumer to ensure everything works together as required.

Craig

The THX crossover is 80 Hz with a 24 dB/octave slope above that. There is no benefit to a sub with upper extension to 200 Hz if you low pass filter it at 80 Hz with a steep slope.


My suggestion is to find out if the Denon uses a 12 dB high pass on the speakers and a 24 dB low pass on the subwoofer for its' 80 Hz crossover. If it does, then it mimics the THX crossover and it will work just as well as a THX receiver/pre/pro for that aspect. Since you are using external amplification, RL is not an issue. Since you will be using Audyssey, and Audyssey performs something similar to most of the THX processing modes, that also becomes a moot point.

Bottom line, if the Denon uses the THX crossover algorithm, and 11.2 is important to you, it will do everything you want.

Craig

I think you found your receiver! Denon used to have a lot of their receivers THX certified, so I'm sure they're aware of the spec's. I have no doubt the 80 Hz crossover would be an exact implementation of the THX crossover.


Steve is a great guy and extremely helpful. He'll give you excellent advice. Tell him I said "Hi".

Craig

1. My biggest concern is with the height speakers. I think their location has been determined mainly by your desire to place them behind the screen. The problem is that if they are placed there, they will not be functioning properly when used as Audyssey DSX Height speakers. One of the important concepts of the Wide and Height speakers is that they fill the gap between the front and surround speakers. In your diagram, you can see that the Wide speaker is nicely filling in part of that void between the surrounds and the fronts. The Height speakers, however, are also meant to fill in the gap between the Wides and Fronts. This is why the recommended angles are 30, 45 and 60 for Fronts, Heights and Wides. In your diagram however, the Heights are located, not between the Fronts and the Wides but between the 2 Fronts. The bottom-line is that I would much prefer to locate the Heights on the side walls, close to its top corner with the false front wall. I think that would be a better compromise.

2. If the surrounds will be at 90 degrees from the main listening position, they should ideally be dipoles.

Other than these 2 comments, I think the lay-out is fine and should sound great.

Mark

With regard to the Height speakers, I can see your concern about having them ceiling-mounted. If they will be only 5' away, there is a danger that they will be localizable. I have also never heard ceiling-mounted height speakers. Chris Kriakakis, the CTO of Audyssey, has said that they would work but I still don't think they would be ideal unless you can actually tilt the drivers so that they point at the Main Listening Position.

The main problem with your plan now is that the Heights have an even smaller horizontal angle than your Fronts. They should be between the Fronts and Wides.

Mark

Can you put the Heights on the walls just beside the subs? This would give you a much better angle and still keep the Heights hidden. I assume that the false wall will have acoustically transparent fabric.

By the way, Audyssey DSX speakers (Wides and Heights) are supposed to be monopole. I don't think it will be a good idea to make them bipole or dipole. I suspect they are also used for panning (which had an extraordinary improvement in my system after installing DSX), in which case they must be monopole. Perhaps the Dolby Height speakers can be bipole but that isn't the case with Audyssey DSX and in my view, DSX is much better than Dolby Height.

Mark

My guess is that even with Audyssey DSX Height speakers that are dipole or bipole, you will still have a positive experience, but Chris Kyriakakis, CTO of Audyssey (see quote above), has specifically stated that they should be direct radiators. It may be different for Dolby Heights.

Mark

I agree that the recommendation of bipoles for the Heights probably considers a Dolby Height system, which is totally different from Audyssey DSX. Between the two systems, I would opt for DSX any time because I've listened to both and DSX has a much bigger positive impact.

A direct radiator is a normal speaker, as opposed to bipoles, dipoles, tripoles, etc. A direct radiator can be a floorstander or a bookshelf speaker. I have seen only two setups with floorstanders used as Heights, one of which was in the Audyssey lab and another was an incredible feat of engineering. Nearly everyone else uses an ordinary bookshelf speaker for the Heights - I do. Typically, you use the same bookshelf speaker for your Heights, Surrounds and Surround Backs.


Mark

Sorry, yes, if your LR surrounds are at 90 degrees, they should be dipoles. For the rears, there are varying opinions but I would agree that they certainly can be bipole. In my own setup, all speakers are direct radiators but this is partly a result of my particular room lay-out.

Yes, I believe that the Wides are more critical. If you listen to them carefully, they have pretty high SPL and the sound is full-range. That's why my own Wides are floorstanders.

Mark

Given that the Wides are more important than the Heights, if I had to use the B&W 805 HTMs, I would use them for the Heights and use the 4400 LR's for the Wides.

I think that DSX is an awesome piece of technology. It's magical. The main feature is that it greatly expands both the depth and width of the soundstage, way beyond the limits of your screen, and it wraps you in a seamless cocoon of sound. In addition, it greatly enhances panning (left to right, front to back, up to down and vice-versa). Once you start reading more about acoustics and psychoacoustics, particularly the topic of good and bad reflections, then you start to get a glimpse at the science behind the technology. In a word, Audyssey MultEQ minimizes the effects of unwanted reflections, while DSX injects the good reflections so as to enhance apparent source width and listener envelopment.

I have an 11.x system. The Wides clearly contribute more. However, when I changed my speakers so that all of them were from the same family, the impact of the Heights was improved. Then, when I installed the Heights at the proper elevation (I had previously forgotten to take into consideration ear height), the effect was improved even more.

My conclusion is that if I were you, I'd get 2 pairs of 4400 LR's and use them for Heights and Wides. Otherwise, you'll always be wondering how much improvement you will have if you change your B&W 805 HTM's.

Mark

Biggest Jamb I've ever seen, one step closer to another great NoVA theater.

Riser concept

Why not mount the Buttkickers to the chairs themselves? Many chairs already have a landing area / mounting spot for the Buttkicker to mount directly to the chair. And then there are other "Brackets" that slip under the feet of the chairs for low or no profile (height) applications. You don't need to build a small riser IMHO.