What happened to my bass?


Ok, for those of you willing to read a bit, I have, as usual, something driving me nuts. I'm a speaker builder. Current speakers look like Watt/Puppy, consist of 11 inch Eton, 7 inch Scan Speak, Scan Speak Revelator tweeter. They perform very well and I haven't changed anything about them in 5 years.....but I have changed houses and of course rooms. Prior room was twice the size of the current, rather small, living room. Bass was a tad shy in the prior bigger room which was in a basement with a good amount of exposed insulation and floor joists up above. Current room is plaster covered drywall, bass traps in front room corners. Bass is generally quite a bit better in the smaller room and according to my pipe organ tracks, very low bass is no problem. So, finally, to the point. Yesterday I am listening to Bygone Days (Eileen Ivers violin track) and it dawns on me that that track has sounded different in the past. In fact, on second listen, there are bass notes completely missing that I clearly remember. I assume the memory goes back to the prior bigger, bass-shy room! I just don't get it. My sense is that bass is fuller and more balanced in this room on everything else I have listened to, and then I get to this Ivers track and there are bass notes that actually had some growl to them, completely missing? It's really wierd when you anticipate something in music and it has disappeared. Room null? By the way, it makes no difference where I am in the room. I even stuck my head behind the speakers. Am I the only one whose system drives them nuts from time to time?
240zracer

Showing 8 responses by 240zracer

Magfan, you are absolutely right. I didn't know about the Rives CD till about a week ago when I stumbled on it here. And my meter is analog.
Thanks for responses! And sorry, I have been out most of the day. I'm 99 percent sure it is not a phase issue. I reserve the 1 percent, because I build crossovers and have discovered many ways to make mistakes. So much so, that the first thing I throw in the player is a test CD. I have a dead center image with only the woofer section of the crossover playing and with the full crossover playing. I think the walls are drywall with "thincoat" plaster on the drywall. Looks like they used a sponge to create texture. House built in mid-forties. Shadorne, about 2 months ago, I was considering the room measurement setup described by Ethan Winer on his site. Generates waterfall plots on a PC. Is that your setup does? Up to now I have gotten by with my Radio Shack meter and test tones. I guess things like this bug me so much is that I consider them setbacks. I will try some things tomorrow and I will definately be taking this Cd to some friends houses in the near future.
I posted this on Ethan Winers forum as well. His response: "Yes, it is probably one or more deep nulls". And he also says to measure the room.
I hear ya, Foster 9! There have been times that I have looked at something 20 times and saw that it was wrong the 21st time. Crossovers are really bad that way. Brand new cartridges with the stylus mounted way out of whack. Imaging seems to play with my head more than anything else, and really the way some music is mixed it is easy to get frustrated. You have to be very careful selecting music to use as a reference. Luckly I have a couple audiophile friends with younger ears than mine.
Results from playing Stereophile Test CD #2 frequency tests and measuring db with a Radio Shack meter, listed as freq/db: 20/64, 25/69, 31/73, 40/76, 50/76, 63/70, 80/72, 100/72, 125/71, 160/72, 200/68. Midrange: 250/62, 315/64, 400/68, 500/74, 630/74, 800/74, 1000/74, 1250/71, 1600/71, 200/72. Treble: 2500/74, 3150/75, 4000/75, 5000/74, 6300/71, 8000/64, 10000/56, 12500/56, 16000/56, 20000/50. Crossover points are 250 and 2500. Not very scientific, but I don't see a reason for missing any bass.
Paulsax....I'm doing all this critical listening (which might be a bad habit) because I had the idea of upgrading parts on my crossover boards. I even built a second order crossover with slightly different crossover points in case I might have a nice surprise. Well, the second order crossover points of 200Hz and 2000Hz resulted in some sharp treble that was not easy to tame, and less satisfying bass. So the forth-order at 250 and 2500 seems to be a winner. I have to believe that some production speakers might suffer from bad crossover decisions just like hobbyists. See if you can find a song called "call me" by Hans Theessink. Talk about a nice raspy voice. I have it on one of those Burmester CDs.
My former, larger room is still what you see when you look at my "system" photos. It was very unusual with all the exposed insulation and floor joists and 2x4 walls. While it was probably a dead room, it also must have been a sound-absorbing room. My bass in that room was definately on the slim side. I am starting to have the opinion that the bass I heard in this track of music, in that room, was probably some anomaly that doesn't happen in my current room. Too bad because the track sounds way better with the bass. I was initially pretty worried that if I was missing something in that piece of music, I must be missing something in general. That really doesn't seem to be true though based on listening and my crude testing. So that CD is going on the back shelf and I say thank you to everyone who chimed in. In time I'll get set up for some better method of measuring response.
Yeah, it was not ideal. It was the best room I had in that house though. There was insulation to the right only, and a big reflecting window, no insulation up above or in the left wall. I had a wider and deeper soundstage there than I do in this smaller room. I built 6-inch rigid fiberglass bass traps for the front corners, and absorbers for the side walls of my current room last winter. I can't figure how bass traps work with the foil facing into the room, but they definately work. I guess sound waves are pretty good at penetrating things. What kind of treatments did you have behind you? Bass traps or high-freq absorbers? Maybe I can learn how to improve my soundstage somehow.