dcstep
dcstep's picture
Offline
Last seen: Never ago
Joined: Sep 16 2007 - 4:59pm
Sumiko Speaker Set
tom collins
tom collins's picture
Offline
Last seen: 11 years 7 months ago
Joined: Apr 3 2007 - 11:54am

great discussion. i have been working on placement with my speakers for sometime now with incremental improvements and you have inspired me to continue. thanks.

tom

dcstep
dcstep's picture
Offline
Last seen: Never ago
Joined: Sep 16 2007 - 4:59pm

Tom, my advice to DIY set up is don't give up on the bass. It's hard to integrate with the mids and VERY sensitive to the slightest movement, with nodes coming and going in 1/4" movements.

The two or three sure signs that you've got it right are; first, the bass production will make it seems as if your speakers are twice as large or more; second, the mids will be even and clear, with no beaming; three, you'll listen at volume settings considerably higher than before, with no distress; four, as you move around the house the sound will hold together better from other rooms as it carries through the structure much more freely.

This is a hard DIY project, so I'd recommend to most that they pay up and have a Sumiko dealer do it for them. For hard core DIYers, start with bass on one speaker, then the other speaker, then get the bass in sync, then mids, then balance and rake. Remember, very small movements can make a giant difference.

Dave

dcstep
dcstep's picture
Offline
Last seen: Never ago
Joined: Sep 16 2007 - 4:59pm

Click on Dave's Virtual System then click on "Sumiko Master set" in my Virtual System to see the jpeg graph of my system's in-room response. Here's the post I added in my Virtual System thread:

At the request of a sceptic or two, I added a graph of the in-room response from 25hz to 200hz. I used that range because that's what's available on the Stereophile test CD. 20hz is down to 65dB and 1000hz is 87dB. The response is very smooth, averaging 85dB. At 31.5hz the response is a pretty healthy 80dB, but there's a dip down to 72dB at 40 Hz. BTW, my average listening level ranges around 85-87dB, so these measurements should correlate well with my listening experience.

It's interesting, this dip is the only serious measured roughness, but it doesn't create a perceived "hole" when listening to music, perhaps because it's so low. Now that I've got 40Hz in my head I'll start listening for it in music. At 50Hz the response is just a couple of dB over the average, reading 87dB.

I may do a more involved study in the near future. It's interesting to note that if I move the speakers back two inches the 50Hz reading bumps up over 90dB. The Master Set apparently removed the peaks and really smoothed the lower midrange and upper bass.

I was a little reluctant to post this curve because I don't want readers to think that the Master Set is all about frequency response. As much effort goes into minimizing Intermodulation Distortion by properly aligning the speakers in relation to each other and the room. I don't know how to measure IM Distortion, but if someone does know, please let me know. I'm really curious to see that.

Still, there's no doubt that avoiding bass nodes and over-emphasis has a big impact on midrange clarity. Before the Master Set, working by myself, I couldn't get both a smooth midrange and a full bass. I ended up sacrificing bass by moving the speakers way out into the room. This is a very common solution, but I think it's really a shame when your system doesn't work to its full potential.

Some people like to insert a complex EQ circuit into the system to electronically do what Master Set did with physical placement. I think that's valid, but I've spent a great deal of effort making my system transparent, detailed and stress free and I doubt that inserting any device will add to that transparency. Also, those insertations may not be able to deal with IM Distortion.

Dave

Log in or register to post comments
-->
  • X