Try moving them out slightly from the wall, or closer... also lifting them off the floor...
When ur in the corner ur loading to the room is quite different than at the wall/floor intersection.
pi space is on a floor, pi/2 is a floor and a wall, pi/4 is floor and two walls (corner).
The freq response is different in each position as are the room nodes.
If you are smack dab into the corner, you are more or less tightly coupled to pi/4, but if you move it out or up, ur then less tightly coupled, so the effect is modified some... if you are able to run a freq sweep or FFT and see the curve in your listening position area that might help as well.
Also, you may be actually hearing the alignment of the speaker - Qts - in a way that you find displeasing, whereas when the same speaker is elsewhere it may be that the "extra" bump in response helps due to a suck out, etc...
One would have to know more about the speaker and the room and the measured response to make a much better guesstimate as to what is happening, imo.
_-_-bear
When ur in the corner ur loading to the room is quite different than at the wall/floor intersection.
pi space is on a floor, pi/2 is a floor and a wall, pi/4 is floor and two walls (corner).
The freq response is different in each position as are the room nodes.
If you are smack dab into the corner, you are more or less tightly coupled to pi/4, but if you move it out or up, ur then less tightly coupled, so the effect is modified some... if you are able to run a freq sweep or FFT and see the curve in your listening position area that might help as well.
Also, you may be actually hearing the alignment of the speaker - Qts - in a way that you find displeasing, whereas when the same speaker is elsewhere it may be that the "extra" bump in response helps due to a suck out, etc...
One would have to know more about the speaker and the room and the measured response to make a much better guesstimate as to what is happening, imo.
_-_-bear
If you can reposition the subs, try pulling them forward so that the distances to the side and rear walls are different. I recently modified by HI-Fi speakers and the extra restiction in the ports tuned them lower - I found I was able to get closer to the corner to compensate with the loss of bass efficiency. I positioned them by just listening at my normal listening position. I found that repositioning the speakers by as little as 2" (50mm) made an audible difference.
Try this trick:
Put the subwoofer in your listening chair, then walk around the room until you hear the best bass. Once you've found the location that delivers the best-sounding bass, put the subwoofer there. Room acoustics work in reverse at low frequencies, so what you hear at your seat should be similar to what you heard when you were walking around the room.
Put the subwoofer in your listening chair, then walk around the room until you hear the best bass. Once you've found the location that delivers the best-sounding bass, put the subwoofer there. Room acoustics work in reverse at low frequencies, so what you hear at your seat should be similar to what you heard when you were walking around the room.
First it's in the corner... So you corner loaded.
Second, as stated a little more technically..
You are at the back wall with the corner at the ceiling again, you get a rolling reflection from that edge, it can be upwards of +3db, although pretty nice if you don't mind the incredible power that the sound can have it's great for when you can't have it up loud.
Second, as stated a little more technically..
You are at the back wall with the corner at the ceiling again, you get a rolling reflection from that edge, it can be upwards of +3db, although pretty nice if you don't mind the incredible power that the sound can have it's great for when you can't have it up loud.
OK, last night I pulled them out of the corners and they really tighten up. Here are a couple plots from the room reinforcement program and it shows (the first one) that the bass is increased but fairly flat. Not so in real life. The next graph show an increase in responce when the subs are pulled out 3' from both the side wall and back wall.
Looking at the first graph, I figured since it was so flat, I could just turn down the volume and had a good flat responce, but noooooo. Didn't work out that way. What gives.
Looking at the first graph, I figured since it was so flat, I could just turn down the volume and had a good flat responce, but noooooo. Didn't work out that way. What gives.
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Taterworks reciprocity suggestion is good advice.
That said, the graphs posted show nothing of the in room response of your subs, and the phase relationship of your subs with your main speakers.
Have you determined that your subs are both in polarity with the mains, and both mains are proper polarity ?
What are you using as a crossover between the two?
Have you taken the subs outside to determine they don't have a big peak that is being reinforced by the corner placement?
Yes, the subs are in polarity with the mains and the mains are right to eachother.
I am using the BASH 300 plate amp and have that set to 100hz and have a 100uf oil cap on the positive side of the fostex.
I don't have any measuring equipment but I did run a step sweep on them and by my ear, there was no Obvious peaks or vallies.
I should also mention that I have two other subs in the back of the room set to a lower volume so the responce anywhere in the room is consistant.
100uf is should be around 3 dB down at 200 Hz for a nominal 8 ohm load, might be hard to dial things in with that much underlap.
It would be lucky if your two other subs happen to match the phase, frequency response, and crossover point of the plate amp subs.
I'd suggest downloading some pink noise for testing, sine wave tones in small rooms are not very useful when you are trying to set by ear.
Put the subs on casters, blow some noise, and start moving things around.
Good luck, have fun!
By ear. Thats is all I have at the moment, so I set up 4 subs and listened. When I had just my one and only sub in the room, there was 1 seat that was over powered and 1 seat in which you could barely hear any sub signal.
Without measuring equipment it is all Guess-and-by-God, but:
1. I was not going to "not" do it because I didn't have the proper equipment
2. It sounds way better than with just one sub.
Without measuring equipment it is all Guess-and-by-God, but:
1. I was not going to "not" do it because I didn't have the proper equipment
2. It sounds way better than with just one sub.
It is essential to assess the sound in some coherent way.
But some people get skilled using tools that seem pretty faulty to others. For example, I've played certain recordings in dozens on set-ups. That's pretty poor for figuring out what freq. are booming as compared to using my ancient Ballantine AC meter or my freeware real-time spectrum analyzer and a mic, but as many people will recognize, actually closer to basic criterion and more meaningful.
I've never been sure if sustained sine waves are a good test or not. Yes, I understand the theoretical acoustical issues but then some wannabe engineers do not understand the musical issue that music has sustained notes in reverberation scale of time.
Worse, how do sweep sine tones relate to things?
Frankly, all things considered, my most useful tool is the PopScience test record sweep tone 300-20 that I've been playing for 50 years. It has chirp markers every 50 Hz and that is altogether more useful than unstructured sweeps even with a stop watch (think of watching and listening for lightening.... kind of the same problem between using the stopwatch and detecting the booms but in terms of perceptual processing, not speed of light!).
I think many people (Golden Ears) are all to confident, even arrogant, that they can hear in an analytic way just by playing music.
But some people get skilled using tools that seem pretty faulty to others. For example, I've played certain recordings in dozens on set-ups. That's pretty poor for figuring out what freq. are booming as compared to using my ancient Ballantine AC meter or my freeware real-time spectrum analyzer and a mic, but as many people will recognize, actually closer to basic criterion and more meaningful.
I've never been sure if sustained sine waves are a good test or not. Yes, I understand the theoretical acoustical issues but then some wannabe engineers do not understand the musical issue that music has sustained notes in reverberation scale of time.
Worse, how do sweep sine tones relate to things?
Frankly, all things considered, my most useful tool is the PopScience test record sweep tone 300-20 that I've been playing for 50 years. It has chirp markers every 50 Hz and that is altogether more useful than unstructured sweeps even with a stop watch (think of watching and listening for lightening.... kind of the same problem between using the stopwatch and detecting the booms but in terms of perceptual processing, not speed of light!).
I think many people (Golden Ears) are all to confident, even arrogant, that they can hear in an analytic way just by playing music.
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Testing 1 2
Hi djn and bentoronto,
My question for djn was about "...setup according to the Geddes paper...". I was just wondering how he was doing this, as it seems to be a method based on rather rigorous repeated measurements.
I am not critical of his methodology as I use listening as my main tool. I use pink noise to identify phasing problems, and a 1/3 octave warble generator which I prefer over discrete sine waves. As I assume most of us, I have a number of recordings that I think I know well enough to be able to identify system differences. In the bass range I found it is very easy to fool myself, and I'm aware that there are great physiological differences in the low frequency hearing between individuals.
But todays digital technology is quickly making the old tools obsolete.
Regards,
Hi djn and bentoronto,
My question for djn was about "...setup according to the Geddes paper...". I was just wondering how he was doing this, as it seems to be a method based on rather rigorous repeated measurements.
I am not critical of his methodology as I use listening as my main tool. I use pink noise to identify phasing problems, and a 1/3 octave warble generator which I prefer over discrete sine waves. As I assume most of us, I have a number of recordings that I think I know well enough to be able to identify system differences. In the bass range I found it is very easy to fool myself, and I'm aware that there are great physiological differences in the low frequency hearing between individuals.
But todays digital technology is quickly making the old tools obsolete.
Regards,
I would like to get some measuring equipment in the room, but no work for going on 14 months now so making due with what I have. Also, this is all going to change as we are moving from this house with a listening room design by the previous owner who was the chief audio engineer for Ford Motor to an apartment.
Yeh, when I said the Geddes paper, I was just refering to the multiple sub set up not the measurment part. Multiple subs sure do make a difference.
Yeh, when I said the Geddes paper, I was just refering to the multiple sub set up not the measurment part. Multiple subs sure do make a difference.
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