...seems better, more 'accurate'? perhaps the synchronization is better now. I wonder if somehow the length of the sub cable affects Audyssey's readings. Although my sub is physically around 14 ft away, I've routed the cable through and under the floor then back up...cable is 35 ft long.

Audyssey sets my subs at 24.5 feet even though they are only 12 feet away. I gave up on experimenting with closer distances when I didn't really hear any improvement - and read countless times that you should not change the distance which has been calculated because of the DSP delay in the EP-500s. Anyway my sub performance really improved when I added a second one.

Your measurements are nearly the same as mine. Next time Alan's on I'll ask him for his advice, seems to sound better set at the actual distance of 14 vs 25 ft, but I don't know if it's because I EXPECTED it too or not.

I was coincidentally able to learn something interesting with my 35 foot cable when I added my second EP-500 and was messing around with different placements. I daisy chained the second EP-500 with the 35 foot cable and immediately noticed a dramatic drop in sound level from that second sub. I had to significantly up the gain to get an equal sound pressure. Didn't like the placement anyway so I abandoned the 35 footer (it was a good coaxial cable). So...makes me wonder about how much signal loss would be occurring with that kind of cable length. I now daisy chain the sub with a 12 foot cable and there is no need to adjust the gain different from the first sub.

IBmack - what you've observed sounds strikingly similar to an oddity in Axiom's amplifiers (particularly EP600) that causes subwoofers daisy chained through them to drop off drastically in volume.

Awhile back someone much more inclined to electric engineering than I (Mojo) measured the input impedance of the amp and determined that it was abnormally high, which causes this effect. The fact that it went away when you switched cables means that maybe the EP500 does not suffer from the same effect, but it sounds so similar that I thought I'd at least mention this problem with the EP600 amplifiers and daisy chaining.

Jason

Placement of the sub makes a huge difference, at least that is what I've found with all these years of trying different scenarios. As I mentioned above, my 600 is now up front dead center between my m80's. If I use the receivers 26.6ft distance for the sub, the only way I get any impressive low results up front is when I have the 80's set to large. However, with the EP600 at 13-14ft distance, I can put the 80's on small with an 80hz crossover.

Now switching back/forth from Stereo 2 CH and Direct mode, it sounds the same, no difference. With the 26.6ft setting, Stereo mode sounded so weak with hardly any bass, and Direct mode was the only way to get any useful LFE.

Also, I have my subs all daisy chained and there is NO signal loss over distances, and there should not be. It is the EP amps that cause this, many have had this issue as Jason has hinted. I'm using a combination of 15ft, 25ft, and a 50ft cables from Monoprice and Bluejeans.

I have an EP500.


My audio engineer friend found something similar the first time he listened to my system. Just a few cannon shots into Master and Commander he cocked his head and said “wow that’s off.” He said that the time alignment between the mains and subwoofer were off. He reset the subwoofer distance from about 25’ found by the Auto Setup to about 18’ (physical distance was about 8 feet) Sure enough we replayed the scene and instead of the cannons going boooooooom? they went BOOM! Even I could tell the difference. Just so happens his hobby is sound effects and cannons are his favorite.


AFAIK you are right Randy. With my 2807 you run the Auto Setup first which determines what channels have speakers, there “size” (lower extension) and distance. These settings remain in the receiver even if the EQ is turned off. Next you run the Audyssey EQ measurements first of which is from the exact same place you ran the Auto Setup measurement from. So it seems to me that the Audyssey builds upon the data collected from the Auto Setup. Unfortunately you can’t (at least on the 2807) interrupt this process and input your own speaker sizes for Audyssey to use. This often resulted in my QS8s being set to large (corner loaded) and occasionally my M80s being set to small. While I change those settings to what I wanted at the end I’m sure it threw off the “perfect” EQ curve Audyssey had calculated based on it’s settings.

Cheers,
Dean

Lol, Dean, that scene in "Master and Commander" was the one I used as a reference when I switched from the Audyssey 25 ft setting to the 'actual' 14 ft setting of my sub, and felt like the timing, or synchronization was greatly improved. This has got me wondering about some of the Audyssey settings, in particular distances, of my other speakers.

I manually entered the actual distances for my speakers in my receiver. After reading this I hooked up my mic and ran YPAO on my Yamaha. It set the distance of my sub to 22ft. Actual distance is 9-10 feet. The mains (M22s) YPAO set perfectly to the actual distances.

Normally I just use the Parametric EQ of YPAO and tell it to skip all other tests. My receiver also lets me edit the Parametric EQ to my own tastes.

I'll have to listen to hear any difference. I'm not sure I have the movie Master and Commander.

Ok maybe I'm not understanding things correctly. I thought the way Audyssey worked was to measure the time it takes from the initial signal leaving the receiver to the time it hits the microphone and thereby compute the corresponding distance based on delay? That being the case it seemed like a pretty reasonable explanation that subs with DSP would look further away than they actually were due to the signal doing whatever it does as it gets amplified and emitted. It is then up to the receiver/Audyssey to adjust the timing of the various signals leaving the receiver so that they arrive at your ear at just the right time. Based on this perhaps faulty understanding it seems to me that arbitrarily changing the sub distance to more accurately match the physical distance will be screwing up the syncronization. Please educate me.

EDIT: I should add that nothing above should suggest that I disagree with the adage if it sounds good it is good.