Home Theater Forum and Systems banner

1 - 20 of 26 Posts

·
Registered
Joined
·
105 Posts
Discussion Starter #1
Last night I received three Ascend Sierra-1s (bought from the classifieds on HTS) and replaced my front three PSB T45/C40 speakers (5.1 system). I did not have the time to re-run Audessy on the Denon 988, yet the Sierra-1's sounded spectacular.

1) This made me wonder if Audessy is mainly correcting for room acoustics and therefore its results are relatively independent of the speakers, as long as the speakers are similarly placed in the room?

Since both PSB and Ascend are designing their products to be as frequency flat as possible across the operating range, they might appear interchangeable as far as Audessy is concerned.
2) If this is so, do I need to re-run Audessy at all?

Thoughts?

Cheers,
XEagleDriver
 

·
Registered
Joined
·
578 Posts
Audyssey EQs your system based on how it interacts with your room. Change one element - a component in the system, something about the room - and the interaction changes.

The two sets of speakers may have similar characteristics, but they won't be identical. I'd re-run Audyssey to ensure that it EQs your system to account for whatever differences may exist.
 

·
Registered
Joined
·
105 Posts
Discussion Starter #5
Gonna agree with eljay and Peter. Definitely re-run Audyssey.
Thanks to all for the advice.

I will rerun Audyssey . . . especially since I just upgraded to 60" plasma and wall mounted the display. So now even the room acoustics should have changed.

Cheers,
XEagleDriver
 

·
Registered
Joined
·
512 Posts
Audyssey EQs your system based on how it interacts with your room. Change one element - a component in the system, something about the room - and the interaction changes.
Audyssey addresses issues that result from the speaker interacting with the room, which will be unique to each speaker and/or room. There is more to it than frequency response.
These posts make it sound like Audyssey specifically addresses issues resulting from a speaker interacting with the room, as if room interaction were separate from the response of the speaker itself and the rest of the system. It isn't, of course, and Audyssey addresses issues everywhere in the system by creating filters in response to measurements of the entire system including speaker response, room interaction, and theoretically even response changes imposed by cabling.

And to be clear, Audyssey corrects for the results of room/acoustic interactions and issues, but it doesn't change room acoustics. Audyssey is very, very good (especially XT32) at what it does, but it's unfortunate the company markets it as an acoustic modifier. It doesn't modify acoustics, it corrects for the result of modified acoustics. Very different. There's no drying up a long reverb time with Audyssey, for example, though it can to an extend work on the effects of non-flat off-axis response in a reflective room.
 

·
Registered
Joined
·
78 Posts
Why is it that every time I run XT32 the place where I put the mic in the 1st position there is 0 bass? I have run it in four different rooms (all differing in sizes and layouts) and every time the results are the same 0 bass from the mic one position, which happens to be the so-called sweet spot, directly between the speakers.

Others have said I have a null but I took measurements with a SPL meter and found none! I followed the extensive manual online and on posts exactly and no difference and understand their explanation reference bass vs preference bass. So I increase the trim levels to get bass there and then it is so overpowering in other parts of the room, specifically the side the sub is on.

Really tough to show off system to others when you say sit in the sweet spot for the imaging, soundstage, vocals, etc. but then sit over here to hear how amazing the bass is! Frustrating!
 

·
Premium Member
Joined
·
15,054 Posts
Why is it that every time I run XT32 the place where I put the mic in the 1st position there is 0 bass? I have run it in four different rooms (all differing in sizes and layouts) and every time the results are the same 0 bass from the mic one position, which happens to be the so-called sweet spot, directly between the speakers.
What are the dimensions of your room? Are you using a tripod for the mic and placing it at ear level pointing up?
Where are your subs located?
 

·
Registered
Joined
·
78 Posts
My room is 14'wx21'd with the couch about 11' back which is where the first mic spot is. I actually use a lamp with a base and a single telescoping rod - the mic actually screws right into the top where you would screw on the nut to tighten down the lampshade. I obviously take off the lamp shade so all I have is one single 1" thick rod that the mic screws onto so for all intensive purposes it's the same as the tripod stand except has a steel base instead of tripod feet.

Yes pointing up!

I mean 0 bass meaning you don't hear or feel any bass other than a little bit from what sounds like it's coming from the speakers and I have it xover at 60 hz. As you move to the right or left you start to hear and feel bass. If you move to the left (side the sub is on) you obviously hear/feel more of it than the right.

I have my speakers set up like this LF - Sub - Center - RF. I am in the process of adding another sub in the next month hoping to balance things off but it's just goofy how this is setup. I have re-run Audyssey many times thinking I've done something wrong but it's pretty foolproof!
 

·
Premium Member
Joined
·
15,054 Posts
Ok I see a problem already, your seating position is dead centre of your room, that is the place wher all the bass frequencies intersect. There is very little you can do other then move your seating back a few feet.
 

·
Registered
Joined
·
78 Posts
I looked a little closer and from the front wall it's 15.5' but the sub is pulled out a few feet out so the distance from the sub to seat position is about 12.5' or so, I think audyssey put it at 11 something or 12 and I have moved the seat back a few feet and nothing changed when I did it (a month or so ago) can't rerun it today with the kids around.

I do know that if I stand behind the couch it is only a pinch better but I want it to get it to where it sounds like it does on the left side - deep, tight, clean with a lot of weight.

Once I get the other sub will that help even things off?
 

·
Registered
Joined
·
78 Posts
Do I just measure the distance with a tape measure and put that value in or can I just slide the couch back, run Audy and then slide the couch back up to trick it into thinking the distance is different?
 

·
Premium Member
Joined
·
15,054 Posts
no, the sub measurement is not actual distance it is taking into account how long it takes for the sound produced by the sub to reach the listening position. Bass frequencies take longer to travel so audyssey has to compensate for that. Normally the distance is around twice as much but not always.
 

·
Premium Member
Joined
·
15,054 Posts
running Audssey is the best way. My thoughts are you need to move your sub to a different spot in the room. Have you done a crawl test? You do this by placing the sub where you sit and crawling around the outside of room playing some bass heavy stuff. Where the bass sounds best thats where you should place the sub.
 

·
Registered
Joined
·
512 Posts
no, the sub measurement is not actual distance it is taking into account how long it takes for the sound produced by the sub to reach the listening position. Bass frequencies take longer to travel so audyssey has to compensate for that.
Not quite. The entire sound sprectrum travels at the same speed through air. The problem with Audyssey getting sub distances right is in the method it has to use to arrive at the number, which is basically an FFT. With all FFTs most of the total information lies from 1KHz and up, and very little data exists from 1KHz and down, and painfully little data exists from 100Hz and down. In an FFT, precision is related to the amount of data you have to crunch, and you get that by taking more time. There's no way to take that time at 100Hz and down with a chirp (or any other time-related sweep), so the data is sketchy, and the conclusions are less accurate. However, since wavelengths at 100Hz and down are huge, it doesn't matter what that distance figure is. Simply not important. However, what Audyssey does better than a standard FFT is arrive at the real, equalizable frequency anomalies even at low frequencies. It does that by its method of combining multiple measurements using "fuzzy clustering", a high-math method of combining correlated data while ignoring tiny location-specific anomalies, thereby increasing the resulting precision at low frequencies way beyond that of a standard FFT. However, that process is not used for distance measurements, and that's not important anyway.
Normally the distance is around twice as much but not always.
I've done a lot of rooms with Audyssey, mostly it comes pretty close, even with subs. I find sub phase determination is far more erratic, and even sometimes the phase determination of the mains can be flakey.
 

·
Registered
Joined
·
512 Posts
So how do I change it to the correct value?
running Audssey is the best way. My thoughts are you need to move your sub to a different spot in the room. Have you done a crawl test? You do this by placing the sub where you sit and crawling around the outside of room playing some bass heavy stuff. Where the bass sounds best thats where you should place the sub.
Try that phase switch first before you move the sub or re-run Audyssey. Check the level control on the sub too, make sure it's up. Check Audyssey's results too, particularly sub level. If it's within a +/- 6dB range, no problem, outside of that you might adjust the actual sub control to put it in range.
 
1 - 20 of 26 Posts
Top