new HSU VTF-15H
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The room is 17'w x 19'd x10h.
I wasn't planning on using both subs until reading about your idea. But now that I have I'll probably take to opportunity to at least experiment. Ultimately I don't think I'll actually use both subs beyond experimenting because the whole reason I bought the Hsu is that I need a sub for the living room. I had my heart set on a PB-13Ultra with plans t retire the 20-29PC+ to the living room. The HSU seems like a good deal and since Batman got one I need to keep my ankle-humping-lemming status up to date. So... if the Hsu box outperforms the SVS tube than I'll move the SVS down to the living room, or vice-versa. The worst thing that can happen is that I fall in love with the performance of two subs in the HT and have to save my pennies to buy another (insert winning sub name here). I kinda doubt it though because I'm pretty darn happy with the single 20-39PC+ that I'm using in the HT now.
I wasn't planning on using both subs until reading about your idea. But now that I have I'll probably take to opportunity to at least experiment. Ultimately I don't think I'll actually use both subs beyond experimenting because the whole reason I bought the Hsu is that I need a sub for the living room. I had my heart set on a PB-13Ultra with plans t retire the 20-29PC+ to the living room. The HSU seems like a good deal and since Batman got one I need to keep my ankle-humping-lemming status up to date. So... if the Hsu box outperforms the SVS tube than I'll move the SVS down to the living room, or vice-versa. The worst thing that can happen is that I fall in love with the performance of two subs in the HT and have to save my pennies to buy another (insert winning sub name here). I kinda doubt it though because I'm pretty darn happy with the single 20-39PC+ that I'm using in the HT now.
There's technically ideal (as measured scientifically and ultimately heard in realism) and there's really fun to do.
It is really fun to mess around with a bunch of subs even if they don't match and the results can be interesting, exciting, and educational.
The ideal would be to use one great sub in one location tuned perfectly. Or, two or more subs equidistant from the listener in different locations.
A flat response, alone, is not indicative of better (more accurate) sound. If multiple subs can be used to smooth the response by means of phase cancelations and waveform distortion (smearing), then the measured response might flat but the realism will be reduced.
I say experiment, play, have fun. Just remember what you are doing isn't necessarily improving the accuracy. If you decide one day to pursue greater accuracy a different solution might be appropriate.
It is really fun to mess around with a bunch of subs even if they don't match and the results can be interesting, exciting, and educational.
The ideal would be to use one great sub in one location tuned perfectly. Or, two or more subs equidistant from the listener in different locations.
A flat response, alone, is not indicative of better (more accurate) sound. If multiple subs can be used to smooth the response by means of phase cancelations and waveform distortion (smearing), then the measured response might flat but the realism will be reduced.
I say experiment, play, have fun. Just remember what you are doing isn't necessarily improving the accuracy. If you decide one day to pursue greater accuracy a different solution might be appropriate.
nelmr
Active Member
Flint said:
I didn't think about the negative effects of "smearing" the sound. By the way I found the following article (among others) mentioned on AVS forums showing why multiple subs are supposedly "better."
http://mehlau.net/audio/multisub_geddes/
I'd like to help the nulls and modes of my room. But if the second sub reduces realism I'm not sure that would be best. What exactly are you referring to with regards to reducing realism?
There are potential benefits when using multiple subs. Technically, I use multiple subs in my room. But, there are also drawbacks when using multiple subs. Most people don't care about the negative affects as they are so thrilled by the peak SPL, flatter response (easy concept to understand), and the sheer raw adrenaline rush of having all those powerful acoustic engines powering up their HTs. Most people only hear thump and oomph, not notes and real sounds.
Often the waveform distortion is very clearly heard if the woofers are not identical and equidistance from the listener, phase and distortion issues can be problematic, and tuning the overall performance can be extremely complex and time consuming.
Often the waveform distortion is very clearly heard if the woofers are not identical and equidistance from the listener, phase and distortion issues can be problematic, and tuning the overall performance can be extremely complex and time consuming.
nelmr
Active Member
Flint said:
Can the waveform distortion be measured using individual sine waves and THD measurements (i.e. measure with the HSU by itself and compare with both the HSU and SVS running simultaneously)?
The REW program does measure THD for 2-9th harmonics. It also give overall THD and THD + Noise. Since I'm using the RS Meter, The THD+Noise figures on my SVS at pretty much any frequency is really high (i.e. 40%+). I assume it's probably a limitation of the RS Meter and the Laptop internal sound card. THD on the other hand is usually around 1-3% or less depending on freq. If using two subs doesn't change the measured THD much, would this mean that using two subs doesn't introduce much distortion? Or is THD not the only distortion to consider.
Regarding my setup, if I use two subs they will be equidistant (HSU front right corner, SVS front left corner).
As regards phase, the REW program can measure that too. I'll have to play with it since I'm not sure what the graphs mean when I turn on the phase option. Here is an example graph on the REW website. The phase plot it the brighter red with the sharp peaks and drops. What does that graph mean?
nelmr
Active Member
Flint said:
What is Impulse? I saw that option in REW, but the graph didn't make any sense to me.
Even if using a calibration file to adjust such as the following:
10.0 -22.09
11.2 -19.25
12.5 -16.83
14.0 -14.69
16.0 -12.66
18.0 -10.61
20.0 -9.05
22.4 -7.64
25.0 -6.49
28.0 -5.33
31.5 -4.41
35.5 -3.61
40.0 -2.99
45.0 -2.41
50.0 -1.97
56.0 -1.64
63.0 -1.34
71.0 -1.14
80.0 -0.96
90.0 -0.86
100.0 -0.80
112.0 -0.82
125.0 -0.82
140.0 -0.88
160.0 -0.93
180.0 -0.95
200.0 -0.99
224.0 -0.94
250.0 -0.97
280.0 -1.00
315.0 -1.04
355.0 -1.04
400.0 -0.95
450.0 -0.92
500.0 -1.03
560.0 -0.95
630.0 -0.96
710.0 -0.79
800.0 -0.44
900.0 -0.17
1000.0 0.00
Dentman said:
In my opinion the emotional connection with music and the technical pursuits of a good system are separate topics but they are not necessarily mutually exclusive. I've heard bad music sound bad on good systems and I've been moved to tears with good music that I've heard on bad systems. My goal is for the system to be as small apart of the equation as possible, unless I want it to be. I also like to have some idea that what I'm hearing is relatively close to what the producer intended. I don't see how I can do either of those things consistently unless I'm starting from a relatively flat baseline.
Dentman
Well-Known Member
If it's a live performance your after then you really need to saty away from a flat responce. Taking measurements is very important, without doubt. But with that said there is a whole lot more to the story as IG infered. I forgot for a while what it was like to try and have these debates, I'll stick to my rule and stay away from audio topics.
I have always said that first and foremost one should love the music and how it is reproduced. If they love what they hear, then great! Don't change anything.
However, if one wishes to experiment to see if an improvement can be made (or not), then learning what ideals might be reached, what hundreds of years of research into acoustical physics and psychoacoustics have taught us about enjoying reproduced audio.
This hobby allows for dozens, if not hundreds, of ways to enjoy music. Every method is good and acceptable. One should be comfortable with their preferences and choices.
However, if one wishes to experiment to see if an improvement can be made (or not), then learning what ideals might be reached, what hundreds of years of research into acoustical physics and psychoacoustics have taught us about enjoying reproduced audio.
This hobby allows for dozens, if not hundreds, of ways to enjoy music. Every method is good and acceptable. One should be comfortable with their preferences and choices.
Dentman
Well-Known Member
Diy, I see your still jealous of those plaid panels.
IG this is by no means a dig on you as you would have no control of this. Also for the record let me make this clear I agree with roughly 90% of what you prech on this and other sites. The truth is most of what I've learned came from you. As a poster it just gets old when it seems that the only advise taken serious is yours, or the people who do nothing more then quote you down to the letter. I stopped posting advice for a long time because of this.
Towen, my remarks are not meant towards you, they are more just a general remark as a whole. IG, do you understand where I'm coming from here? I hope you can see that I hold no grudge against you for something you have no control over. It has to get old when you never hear a different view point or challenge, well aside from the occasional nut job who gets all pissed off because you didn't like a pair of speakers they think are the end all be all.
I'll just step off to the side again and let the same old same old ride, it's all good. It's not like your giving bad advice, anything but (Health Care aside). :teasing-neener:
IG this is by no means a dig on you as you would have no control of this. Also for the record let me make this clear I agree with roughly 90% of what you prech on this and other sites. The truth is most of what I've learned came from you. As a poster it just gets old when it seems that the only advise taken serious is yours, or the people who do nothing more then quote you down to the letter. I stopped posting advice for a long time because of this.
Towen, my remarks are not meant towards you, they are more just a general remark as a whole. IG, do you understand where I'm coming from here? I hope you can see that I hold no grudge against you for something you have no control over. It has to get old when you never hear a different view point or challenge, well aside from the occasional nut job who gets all pissed off because you didn't like a pair of speakers they think are the end all be all.
I'll just step off to the side again and let the same old same old ride, it's all good. It's not like your giving bad advice, anything but (Health Care aside). :teasing-neener: