AudioNervosa
Systemic Development => Bipolar System Disorders => Topic started by: James Edward on January 14, 2023, 02:57:49 PM
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I’m really enjoying what I’m hearing from my system- I’ve got one sub now, and giving serious thought to adding a second. Any thoughts one way or the other? As my title implies, they’re both going up front.
I was never able to make a large set of speakers deliver tight bass- placement and problematic room caused various booming that I could not tame. That’s why subs and open baffle speakers. Q control on the sub really seems to tighten things up.
A single sub is serving me pretty well- overall great sound but a few holes/nulls as I move around the house.
Equipment list below if it helps.
Jim
PS- Just played a bunch of 12” 45 RPM records- man they sound great.
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For optimal sound, subs are always supposed to be used in pairs (2, 4, etc.).
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Sounds good- no pun intended to
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+1 on the pair. Unless it has DSP. A big help. I like the Golden Ear Sub with DSP as a single sub or Rythmic with no DSP in a pair.
charles
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At least two...
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I had one for the longest time, but man things really changed for the better when I added a second one.
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Stereo here, but always thought a SWARM sub setup would be interesting to try.
Heard that at RMAF a few times with really good results.
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Four is better than two😁
You may also get a much flatter bass response if the two in back are 180° out of phase
with the front two.
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Four is better than two😁
You may also get a much flatter bass response if the two in back are 180° out of phase
with the front two.
That is an interesting point , and there is truth behind it. Here is a relatively recent article on the subject of out of phase speakers when on the opposite side of the room:
https://boomspeaker.com/subwoofer-phase-0-or-180/
The thing is, in my experience, it's more trouble and problematic to achieve than it seems. In this case, the "it's" I'm referring to is when you opt to fire speakers (subs or not) towards/at each other.
In my opinion, that doesn't work well for two channel stereo listening. Surround sound, perhaps.
Correctly implementing a sub with other speakers is difficult on its own. Having them fire towards one another just makes an already difficult task even more difficult, if the end goal is to achieve optimum sound quality.
Besides that , if you're going to spend on four quality subs , you're probably better off spending on two subs and then spending the additional money on room treatments.
Best.
Hal
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The article needlessly complicates the subject. The speed of sound is about 1,100/sec.
Roughly speaking a sound wave travels about 1ft/milli-second. Ideally your receiver would have more than
30 milli-seconds of total delay available. This would allow you to cancel the bass sound wave
before it could hit the back wall of most listening rooms. If you can reduce this primary
reflection's amplitude sufficiently you can achieve far flatter bass frequency response
at the listening position than is normally achieved by any other stratagem that I am aware of.
Even if you don't have a receiver with delay, a worthwhile improvement can be had
by had reversing the phase of the sub or subs behind your listening position.
If you have reduced the magnitude of the reflected bass from the wall behind your listening position
you should hear a marked improvement in the spaciousness of the sound stage
and an improvement in the stereo image. The bass should also have a quite noticeable reduction in bloat and boominess.
I run two Rythmik L12 subs in reverse phase and a QSC DSP 30 digital delay set for 15 milli-seconds of delay.
Scotty
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"The speed of sound is about 1,100/sec.
Roughly speaking a sound wave travels about 1ft/milli-second." - _Scotty_
Assuming that the 1100 in your quote is meant to represent feet then this would be true. The operative word there is roughly because the speed of sound is a variable depending on temperature and other environmental variables.
I'm on the road now and cannot give this thread (my response) the attention perhaps it deserves but those two equations are basically indicating the same thing. First you're using the word " sound " and then "sound wave"... they're the same thing, traveling at the same speed.
"If you can reduce this primary
reflection's amplitude sufficiently you can achieve far flatter bass frequency response
at the listening position than is normally achieved by any other stratagem that I am aware of." _Scoty_
I did previously write that you have an interesting point and there is truth behind it.
All I'm saying is it's a lot easier to put it on paper or make a post here in the form thread than to actually implement it (four subs two of which are facing the other two) for the betterment of sound. If you've achieved that , then that's terrific and kudus to you.
For the type of music that I listen to and my preferences, I personally would never use that arrangement. I'm a two channel, two speaker person (in my case this two speakers have built-in subs). Both speakers are firing in front of me.
I never cared to listen to anything recorded where sound is coming from above me, behind me , to the sides of me , or from any other place than the front of me.
And I believe that proper room treatments are essential to achieving good frequency response and that would be true regardless of however many speakers you use and where you're placing them.
The answer to the ops question though appears that we all universally agree. Get another sub for a total of two. Or, get another three subs for a total of four. The placement of those subs becomes a completely different issue, and technically outside of the scope of the ops question.
Best.
Hal
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I helped a person with a 4 sub setup. The rear subs had to be closer to the listening position and was causing cancellation. I used the dspMusik 2x8 DSP XO and added time delay to the rear channels. After getting everything dialed it his comment was "It now sounds better than the pipe organ at my church" It had bass response after the time delay at the listening position. Not that hard to setup.
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Four is better than two😁
You may also get a much flatter bass response if the two in back are 180° out of phase
with the front two.
I remember your sub set up. The best I have heard in a Home.
charles
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Thanks Chuck, the system only has to make 2 people happy, me and my wife. That it satisfied a
third person is pure gravy. Especially considering you're a picky cuss. 😆
Scotty
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Thanks Chuck, the system only has to make 2 people happy, me and my wife. That it satisfied a
third person is pure gravy. Especially considering you're a picky cuss. 😆
Scotty
I recall sitting right next to the sub and heard nothing from it. Well done
charles
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Thanks Chuck, the system only has to make 2 people happy, me and my wife. That it satisfied a
third person is pure gravy. Especially considering you're a picky cuss. 😆
Scotty
That is true on all accounts. :D
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Thanks Chuck, the system only has to make 2 people happy, me and my wife. That it satisfied a
third person is pure gravy. Especially considering you're a picky cuss. 😆
Scotty
I recall sitting right next to the sub and heard nothing from it. Well done
charles
Charles, sitting right next to a sub may not be the optimal way to judge it's performance. Low frequencies take many feet for the waveform to fully propagate/develop.
Best.
Hal
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At the time Charles was completely inside the zone of cancellation and the woofer output volume was quite
low,only enough output to cancel out the bass coming from the front. The rear woofers are supposed to contribute next to nothing to the perceived volume of the bass at the listening position. If you can localize them or realize that they are back there at all they set for too high an output or crossed over too high or both.
The object here is that you shouldn't know they are there and operating at all unless they are turned off
while listening to a passage of music. Then you hear the problems they were solving.
I haven't posted this link to a deep dive on the use of multiple subs to optimize low frequency response
in listening rooms in a while. This is a link to the PHD Thesis of Adrian Celestinos.
From the thesis "The scope of the thesis and the research concerns itself with the performance of loud-speakers in rooms at low frequencies. The research concentrates on the improvement of the sound distribution in the room produced by loudspeakers at low frequencies.The work focuses on seeing the problem as an acoustic problem in the time domain."
https://vbn.aau.dk/ws/portalfiles/portal/12831869/AC-phd.pdf
Since I first ran across his doctoral thesis it appears that he has done well and is now working for Samsung
as senior DSP engineer, cool. https://www.aes.org/events/139/presenters/?ID=3714
Scotty
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Hi _scotty_
I have no reason to doubt you have an amazing sounding system, and frankly I'd love to hear it at some point assuming that it's logistically possible and you're up for company.
You write very intelligently and informatively. And you've also gotten Charles to write how grate your system sounds :)
You're also posting links from people with phds and thesis data on the subject, so I'm personally in no position to question that type of authority.
To your point about the subtleties of the sub woofer so as to not draw unnecessary attention to itself , that too is very very true.
But this is the reason that I'm stating that it's not so simple to implement. I'm sure you'll agree you have two basic components to the matter ( some other things too but the two basic major ones) which are your crossover frequency (where the sub begins to kick in) and the output level setting.
The sub shouldn't be noticable (meaning shouldn't draw unnecessary attention to itself) when it isn't needed, meaning it isn't being called for by the source content of the recording.
On the other hand, setting the subs in such a subtle manner has to be balanced with the fact that there is plenty of music content that demands the use of subs in all of its glorious splendor.
For example, play (assuming you have access to this music) mickey hart - The Gates of Dafos - vinyl remaster 1644.
When played at a proper decibel level , say 90 DB or above, your subs should essentially emit such power, that it now gives you an opportunity to check if there are any unwanted resonances in the room. In other words, the bass and subbass is anything but subtle. The sound would certainly be penetrating walls.
Now what I don't know (have never tried it) is if using four subs in total (two in the rear and two in the front) means that the two that are in the rear and out of phase (as you suggested) firing towards the front subs is going to result in an accurate representation of how that particular song track should sound.
I suppose this is one of those cases where life is not being in the "know", it's being in the "mystery".
Best.
Hal
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Thanks Chuck, the system only has to make 2 people happy, me and my wife. That it satisfied a
third person is pure gravy. Especially considering you're a picky cuss. 😆
Scotty
I recall sitting right next to the sub and heard nothing from it. Well done
charles
Charles, sitting right next to a sub may not be the optimal way to judge it's performance. Low frequencies take many feet for the waveform to fully propagate/develop.
Best.
Hal
Not according to Paul McGowan. I say dont rule anything out. Try it, if it doesnt work, change it.
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Thanks Chuck, the system only has to make 2 people happy, me and my wife. That it satisfied a
third person is pure gravy. Especially considering you're a picky cuss. 😆
Scotty
I recall sitting right next to the sub and heard nothing from it. Well done
charles
Charles, sitting right next to a sub may not be the optimal way to judge it's performance. Low frequencies take many feet for the waveform to fully propagate/develop.
Best.
Hal
My comment was about that I did NOT hear it being so close was the point. That is the trophy
charles
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Not according to Paul McGowan. I say dont rule anything out. Try it, if it doesnt work, change it.
I've seen, as we all have, a number of PS Audio (a.k.a. our beloved Paul McGowan) youtube videos. I think he's usually correct. I recently watched him doing a video about room treatments, and I think (not sure though) it was related to his latest speakers Aspen FR20. Or it could of had something to do with his listening room with the iconic Genesis speakers. Anyway, he talked about the front wall. And BTW, he went on for a minute or two to clarify that some folks refer to it as the back wall but clarified that he meant by the front wall is the wall behind the speakers (i.e. behind the way the drivers are facing/firing). He was adamant to state that no room treatment should be applied to that area. Seriously? I mean, maybe if your room is professionally designed where the wall itself is an absorber/diffuser combo perhaps but in the typical home environment? His statement in that regard cannot be true. I've had two acoustic engineers at my place, and one virtually - courtesy of GIK acoustics - all of whom claimed I needed absorption behind (front wall) my speakers.
Moral of the story, as with anything else, consider the information with a grain of salt.
Let's see with our heart
These things our eyes have seen
And know the truth must still
Lie somewhere in between
Blues For Allah
Lyrics: Robert Hunter
Music: Jerry Garcia
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There seems to be a pair of Ryhmic Subs knocking at the door. FS12G that is. Pull the trigger do not pull the trigger.
charles
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Just pulled the trigger on a second Hsu ULS 15 Mk2. Ordered Belden 12 gauge 2 conductor to feed each one. The only issue I have, and not a biggie, is getting power to it in an unobtrusive manner. System is in my living room, so I’m going to try an ‘under carpet’ power cord. I have a pretty good way to conceal the speaker cable, but I don’t want the A/C cord running parallel to it.
Someone here posted some flat power cables from Amazon; I’m going to try one of those, but if the sub gets here first, oh well, aesthetics can wait- I have plenty of orange extension cords.
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Just pulled the trigger on a second Hsu ULS 15 Mk2. Ordered Belden 12 gauge 2 conductor to feed each one. The only issue I have, and not a biggie, is getting power to it in an unobtrusive manner. System is in my living room, so I’m going to try an ‘under carpet’ power cord. I have a pretty good way to conceal the speaker cable, but I don’t want the A/C cord running parallel to it.
Someone here posted some flat power cables from Amazon; I’m going to try one of those, but if the sub gets here first, oh well, aesthetics can wait- I have plenty of orange extension cords.
Best of luck with your new (second) sub, James. :)
Besides the logistics of the power cord, I imagine you may run into challenges integrating the sub "seamlessly" into the rest of the system. It can be challenging in a good way though. :)
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Just pulled the trigger on a second Hsu ULS 15 Mk2. Ordered Belden 12 gauge 2 conductor to feed each one. The only issue I have, and not a biggie, is getting power to it in an unobtrusive manner. System is in my living room, so I’m going to try an ‘under carpet’ power cord. I have a pretty good way to conceal the speaker cable, but I don’t want the A/C cord running parallel to it.
Someone here posted some flat power cables from Amazon; I’m going to try one of those, but if the sub gets here first, oh well, aesthetics can wait- I have plenty of orange extension cords.
Jim,
I was going to suggest one of those flat cables. Let us know how it works out
Nick
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Just pulled the trigger on a second Hsu ULS 15 Mk2. Ordered Belden 12 gauge 2 conductor to feed each one. The only issue I have, and not a biggie, is getting power to it in an unobtrusive manner. System is in my living room, so I’m going to try an ‘under carpet’ power cord. I have a pretty good way to conceal the speaker cable, but I don’t want the A/C cord running parallel to it.
Someone here posted some flat power cables from Amazon; I’m going to try one of those, but if the sub gets here first, oh well, aesthetics can wait- I have plenty of orange extension cords.
BTW, running parallel is wise to avoid, but not to be obsessed over either, especially if the distance between the cables is > 1ft and/or one of the cables has rfi/emi shielding.
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Just pulled the trigger on a second Hsu ULS 15 Mk2. Ordered Belden 12 gauge 2 conductor to feed each one. The only issue I have, and not a biggie, is getting power to it in an unobtrusive manner. System is in my living room, so I’m going to try an ‘under carpet’ power cord. I have a pretty good way to conceal the speaker cable, but I don’t want the A/C cord running parallel to it.
Someone here posted some flat power cables from Amazon; I’m going to try one of those, but if the sub gets here first, oh well, aesthetics can wait- I have plenty of orange extension cords.
BTW, running parallel is wise to avoid, but not to be obsessed over either, especially if the distance between the cables is > 1ft and/or one of the cables has rfi/emi shielding.
Yeah, my speaker cable to the Spatials is not shielded, nor is the speaker cable I will be running to each sub, and I don’t have a foot to spare. The flat cable will allow me the distance I need under the rug. I’m a bit fanatical about noise/hum, etc.- no chargers, dimmers, LED’s, allowed near the system. I’m all incandescent too- a different topic for a different day, but I loathe LED and fluorescent lighting.
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I’m a bit fanatical about noise/hum, etc.- no chargers, dimmers, LED’s, allowed near the system. I’m all incandescent too- a different topic for a different day, but I loathe LED and fluorescent lighting.
As well you should be. LED, fluorescent, quartz lighting are nothing but little radio stations. When I was designing recording studios, I spec'd the lighting to be in banks of lights instead of using stage dimmers which are still noisy.
Low light - first bank
Medium light add bank #2
Bright lighting - Add bank #3
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So… Some details- The second sub is in place and hooked up. I’m using Belden 12 gauge for wire. I haven’t gotten the flat power cord yet, but I’ve been monitoring for noise or hum, neither of which has surfaced. I quite literally have an extension cord running alongside the main speaker wire and sub wire, with zero noise. If I put my ear up to the tweeter at full volume I hear a bit, but I’ve heard much worse in my own system and in others. At normal ‘high volume’ there is no noise.
I’m still dialing them in- Hsu phone help is very good, patient and knowledgeable. I’ve had several calls just going over ‘what ifs’ and various setting scenarios. There’s volume, two EQ settings, Q, phase; with two subs there seems to be more interaction both room wise and with each other. Having an asymmetrical room doesn’t help matters.
So far though, so good. My main goal, having it sound like there are no subs, is being achieved.
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So… Some details- The second sub is in place and hooked up. I’m using Belden 12 gauge for wire. I haven’t gotten the flat power cord yet, but I’ve been monitoring for noise or hum, neither of which has surfaced. I quite literally have an extension cord running alongside the main speaker wire and sub wire, with zero noise. If I put my ear up to the tweeter at full volume I hear a bit, but I’ve heard much worse in my own system and in others. At normal ‘high volume’ there is no noise.
I’m still dialing them in- Hsu phone help is very good, patient and knowledgeable. I’ve had several calls just going over ‘what ifs’ and various setting scenarios. There’s volume, two EQ settings, Q, phase; with two subs there seems to be more interaction both room wise and with each other. Having an asymmetrical room doesn’t help matters.
So far though, so good. My main goal, having it sound like there are no subs, is being achieved.
Tweak on, Brother, tweak on! 😁
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..........So far though, so good. My main goal, having it sound like there are no subs, is being achieved.
Hi James. I don't think you literally mean the portion of your post I've quoted. Just my .02 and opinion, but having your system sound like there are no subs defeats the purpose. If you want your system to sound like you have no subs, don't use any. The trick is (and this is what I eluded to previously in this thread) is to have them integrated properly, which isn't necessarily all that easy to do. You want to hear/feel the subs at the appropriate time, when the music content calls for it. When heard/felt, it could be subtle or not so subtle, again, depending on the music (sound if home theater).
Glad to read it's working out to your liking though. :)
Best.
Hal
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Yes Hal- not literally, but in the audiophile sense of having them disappear as a source but still contribute when the music dictates.
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Still tweaking… Had a couple of people over and they gave me some things to consider and things to try.
I had initially modeled my second sub settings on the initial one I had.
After careful analysis with an SPL meter and test tones, it became apparent that one sub had significantly louder db levels because of its placement in the room. I’m talking 10-11 db louder!
I addressed that, and the sound improved.
My guest also felt that a closer listening position sounded better- he was right, and my listening chair is now two feet closer to the speakers. I rarely listen ‘critically’, and rarely sit in this chair, but the difference was significant enough to make the change permanent.
Today, I broke out the meter again to experiment with phase settings… Much to my surprise, even though the subs are up front and facing the same way as the mains, the 180 degree phase setting had about a 2-3 db higher output than 0 degrees. I never expected that. I used tones just above and below 50Hz, where I have my sub’s crossover set.
I’d say the sub tweaking yielded 5-10 per cent better sound, and the chair movement, when listening critically, as much or more.
“We suffer for our craft,” as my guest jokingly said.
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I will add that perhaps the phase setting that I find counterintuitive is due to my open baffle speakers? The subs are basically 18” behind the mains, also toed in to the listening area, but at a little more of an angle.
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I'm pretty sure that there is no universally correct phase setting, because it can vary by virtue of the source recording (and other components). One phase setting should cause the woofer to move outward. The other or out of phase setting should cause the woofer to move inward. Absolute in phase is achieved when the microphone diaphragm moves inward and the speakers reproduce that by having their diaphragm move outward. There's no right or wrong per se and listener preference usually prevails. I'm just pointing out that don't be surprised if you find (hear) "better" bass with the phase set the opposite way you have it, with certain recording. I have the ability to invert phase with my DAC, but never do. I live with one setting, so I set it and forget it so to speak. But I know that ideally, I should change it every now and again, depending on what I'm listening to.
Glad to read your making improvements, experimenting, etc. :)