My "adventures" with the Velodyne SMS-1 (experts needed -- help)

V

Vaughan Odendaa

Senior Audioholic
I'm located in South Africa. Curt has helped me but his help has reached it's limit. He tells me that there is nothing more that I can do and that because my peaks have been reduced that it gives less perceived deep bass.

Fair enough.

But then I also increased (by a fair margin) a large portion of the FR to get a flat response. So whatever peak I may have had should be offset at the overall increased FR at my location.

He tells me that if I'm not satisifed that I should talk to my dealer and get a possible refund. My dealer popped around and I told him that the SMS-1 is a wonderful tool and that it has made a difference.

I don't think I'll get a refund. But I did spend a lot of money on this thing and IMO, at least not yet, does the price warrant the performance I've achieved.

Like I've said before, perhaps I've done something wrong. I will take your suggestions to heart. I'll re-eq my response but will tweak using the phase control in the SMS-1 first before making any drastic changes.

Apparently, everything I've done is correct. I played back Master and Commander at MV -8, both settings have ample power. But I can't seem to tell a big difference in bass clarity.

The range has been boosted, especially in areas which had big dips and I can't honestly tell that there is difference. In music, this is completely different. I can hear a difference.

I do listen to music but I am even more of a film buff and I like to calibrate flat for films. I don't like overblown bass that drowns out the midrange and high frequencies. So I don't know.

Now I don't know if I'm doing this right, but let me explain a few things. After I EQ my graph for a flattish result, I leave the SMS-1 volume alone (it's 15 at the moment) and go directly to the pink noise in my AVR and calibrate the levels of the sub. But I don't touch the subwoofer level. I use the SMS-1 volume to calibrate at this point because I want to compare results between a level matched flat response and a level matched uneq'ed response.

With my uneq'ed response, I need to use a volume on the SMS-1 as 37 which is very high. My subwoofer level in my AVR is at it's very lowest setting, -10. Using the SMS-1, I find that in order for me to get a flat reading (73-74 dB's), I need to increase the SMS-1 volume from -15 (which is the baseline measurement level for both settings) to around -19.

The only reason why I've chosen the sub level so low is because of reports of input distortion on the SMS-1. This is not conclusive but one unit has exibihited large amounts of distortion in the input stage.

Should I increase the sub level and decrease the SMS-1 volume ? So if I toggle between the eq'ed results and the uneq'ed results, the volume for both presets are as follows for measured flat level calibration --

Eq'ed -- -19 on SMS-1
Uneq'ed -- 37 on SMS-1.

Have I done something wrong or am I doing this correctly ? Thoughts and suggestions would be most appreciated. I just would like to also say thanks to all those who have participated and who are trying to help me with this tool.

It is a tool and I think it's great for diagnosing problems. Although it is expensive IMO. :)

--Regards,
 
V

Vaughan Odendaa

Senior Audioholic
Alright, I have some new graphs. I changed something that I never thought would make a difference in my system. I changed polarity from positive to negative.

My word. The difference was substantial.

Graph one : unequalized



Graph two : equalized



Finally, graph three : equalized (slight boost between 15-19 hz 3 dB's )



Right, so what do you guys think ? Thoughts ? Suggestions as to how I could improve the graph ?

Thanks very much.

--Regards,
 
V

Vaughan Odendaa

Senior Audioholic
Just a thought : My subwoofer is placed in the corner (spaced 3-4" from the wall) if I place a subwoofer in a corner the decay times of deep bass frequencies will be longer than if spaced away from, correct ?

If I achieve two graphs that are identical in every way but are in different physical positions, one being in a corner and the other spaced 2 to 3 meters out, would my decay times be substantially better ? I wondering if I could improve on my decay times as a temporary measure by taking the sub out the corner and perhaps equalizing for flat response a bit closer to my position.

Music should benefit and movies too.

Just pondering. :)

--Regards,
 
newsletter

  • RBHsound.com
  • BlueJeansCable.com
  • SVS Sound Subwoofers
  • Experience the Martin Logan Montis
Top