Definitive Technology Mythos Series Thread - Page 114

Hi, hipertec:

First of all, what a beautiful room!

What exactly sounds off to you? Is it a muddy center channel, lack of bass, too much bass, non-convincing surround field?

Here's a few thoughts:

1. The most important instrument in your room is the room. Many problems can be traced back to the room characteristics. What are the dimensions of your room. Where are your seating positions located? If they are on any of the even fractions of any axis, your system will not reach it's full potential.

2. Distances are tough to judge on photos, but I think that if you are looking to improve the surround image, your side/rear surrounds are too close to your seating positions to use direct radiators. I would suggest moving your side and rears up as high as you can go to make them less localizable. Also, you might consider switch to bipole/dipole speakers to avoid firing towards the listening positions. (I used the Def Tech UIW surrounds as my side surrounds for this reason--they are voiced the same, but have a bipole-like configuration that are much more diffuse). If that is not feasible, you might be able to aim your direct radiators to bounce off a side surface to diffuse things better than you have currently.

3. I agree with Snowmanick. Audessey has been known to do some weird stuff at times. I'd try a manual/SPL meter calibration first and use a laser to aim your fronts and center to see how things sound with Audessey off. If you aim your fronts so that their axis intersects just in front of your primary listening position, you may find you have a much better soundstage (this is the case in my set up). Also, it's surprising how many centers are misaimed.

4. Be sure you are blending that extra sub carefully. I use a Velodyne sub-EQ; SVS makes one as well. If you aren't careful with your phases and EQ, those subs could be causing peaks which could be harming the midbass and treble of your Mythos' This will result in just a dull sounding set up. I was surprised at how much better things sounded in my dual sub setup when I carefully EQ'ed things and was able to see an FR curve.

5. The Mythos are excellent at music. In fact, it's a real strength in terms of how articulate the midbass and upper end are. (there is no midbass hump by design.) However, the subs need to be blended carefully (not an issue with your STS, but that second sub may be messing with things--see above). You might also try moving the STS away from the boundaries a little to see if that helps--the ideal space for your subs may not be the ideal place for your mains--you'll have to experiment to find out, and it's amazing what a few inches will do.

6. You mentioned that one of your subs is in a cabinet. Are any of your front three in a cabinet? That may be the issue right there. Mythos' need to be free!

7. Perhaps the most efficient way to solve your issues is to get a professional calibration. You'd end up with a top tuned system if the calibrator is good, and you wouldn't have to mess with it yourself (although I personally think that's half the fun!) They can also make better recommendations than I with regards to room treatments, etc.

Good luck!

Hi, hipertec:

If the bass in one row is markedly different that the other, that implies that your first row is sitting in a bass null.

Can you show us a schematic with actual measurements in terms of the placement of your head in the front row at the primary seating position? I'd guess you are sitting at some multiple of 1/2; 1/4; 1/6; or 1/8th dimension of your room length, width, or height. If that's the case, you'll need to adjust the positon of the row to get the best results.

You can smooth out your bass with a second sub, but it has to be thought out well and there is some trial and error--you'll need at least an SPL meter and the ability to adjust phases on your subs. It's not that complicated usually, but it does require some care.

As others have pointed out, I'd start with optimizing your room, seat positions, and speaker placement first before investing in new equipment--you'll likey be amazed at the results.

PS: Before I forget, the rear surrounds problem is likely because your second row is behind the main surrounds. (Even if your receiver has the capability to matrix 5.1 mixes into 7.1 mixes in your receiver, the majority of the sound you're going to get in the rear row (from the rear surrounds) won't provide a great surround experience. ) One way to deal is to raise those surrounds up and consider moving the back row forward or move the side surrounds back a little and/or bounce them off something. All bipoles in the back might help, but I suspect the position is the key. If space is an issue, you might even consider going ceiling mounted for the side surrounds--this is what I did with the Def Tech Bipoles and it worked out really well for me. In addition, those beautiful rear drapes are probably also helping deaden some of the reflections from the rears, which may be hampering the surround effect as well.