Audioholics: please tell me if I’m crazy (for considering a subwoofer purchase)

[ATLAudio]

REW is a free app for use with a laptop, along with a MiniDSP Umik1 ($70?) is what most folks around here use. You can see how your sub behaves and with a ($100) MiniDSP 2x4 you can load in EQ adjustments.

A few caveats...

REW is not the easiest application for the lay person, and I'm an SAP specialist by trade.
After Audyssey you'll likely gain little based off what I'm seeing.
It's an f***rabbit hole.

 

[shadyJ]

Could you point me in the direction of the type of measurement microphone that you have suggested? Do you know of any online tutorials where I could learn the best way to calibrate subwoofer(s) using one of these microphones? Many thanks.

It isn't all that complicated. To make everything simple, I would go for a UMIK-1 calibration microphone and a miniDSP 2x4 for equaliztion. Setting up the mic and taking measurements is easy. You will want to download REW. Just plug the mic in, and select your mic as the input device in REW. Select the appropriate output device in REW, then just take a few measurements. We helped someone through the process recently in this thread.

Here is a simple guide to connecting the mic and taking measurements.
Here is a guide on how to EQ the subs once you have the response.

The in-room frequency response is by far the greatest determinate of the sound quality of bass. Whatever subwoofers you decide on, proper placement and EQing the room response will make them a much greater value. Audyssey can only clip peaks, but to shore up nulls you will need to resort to placement and measurement. To do that effectively, you need to know the response.

 

[Henry Howards]

It isn't all that complicated. To make everything simple, I would go for a UMIK-1 calibration microphone and a miniDSP 2x4 for equaliztion. Setting up the mic and taking measurements is easy. You will want to download REW. Just plug the mic in, and select your mic as the input device in REW. Select the appropriate output device in REW, then just take a few measurements. We helped someone through the process recently in this thread.

Here is a simple guide to connecting the mic and taking measurements.
Here is a guide on how to EQ the subs once you have the response.

The in-room frequency response is by far the greatest determinate of the sound quality of bass. Whatever subwoofers you decide on, proper placement and EQing the room response will make them a much greater value. Audyssey can only clip peaks, but to shore up nulls you will need to resort to placement and measurement. To do that effectively, you need to know the response.

Thanks for all the helpful advice and links. Because of the small dimensions of my home, I have limited options for subwoofer placement (that diagram of my studio leaves out a lot of the furniture in the room, such as the fold-down futon frame I sleep on...) It's probably a good thing I'm an old bachelor and I don't have to contend with the additional complications of SAF (Spouse Acceptance Factor).

 

[Henry Howards]

It's a f***ing rabbit hole.

That's what scares me a little...

 

[lovinthehd]

Nothing horrible about starting by choosing the best among your possible sub location options, run the avr's Audyssey routine and enjoy.

 

[Henry Howards]

Nothing horrible about starting by choosing the best among your possible sub location options, run the avr's Audyssey routine and enjoy.

Thanks. There are four subwoofer placement options that are available to me, and with any luck, one of those four will work well.

 

[ATLAudio]

Thanks. There are four subwoofer placement options that are available to me, and with any luck, one of those four will work well.

One great thing about your set up is that you're already off-set from the squarish dimensions of your room. It's incredibly common for folks to set up their main listening seat dead center in a squarish room, and that's literally the worst place for small room sub dynamics.

If you go with an S1500 from PSA and after a week or two, you wish you went bigger, I think you could work out something with Tom at PSA, but you'd need to call him and discuss it. I'm not saying he'd let you do a free upgrade within a month tryout, but I wouldn't be surprised if he did. Since you have the $2k budget in mind, it wouldn't hurt going with something a little bigger for a single sub. Take a look at the S1800, he's also taking opening orders on the new S1801; something I'd take at look at if I were you!

 

[Henry Howards]

One great thing about your set up is that you're already off-set from the squarish dimensions of your room. It's incredibly common for folks to set up their main listening seat dead center in a squarish room, and that's literally the worst place for small room sub dynamics.

I was fortunate that this arrangement produced good acoustical results, because as I mentioned earlier, due to the placement of doors, windows, cabinets, appliances and furniture in this studio, the only possible positions for my loudspeakers and television are the exact spots they now occupy. I have had these same Paradigm speakers set up in different room environments before this one, and I am convinced that they sound better in this studio than anywhere else I have heard them. Several of my guests have had a similar response. When I play music or a movie, their first remark will often be, "That sounds really nice." I admit I have a few lingering doubts about buying a subwoofer for this place. I don't want to screw things up by introducing a sub that might disturb this good balance.

If you go with an S1500 from PSA and after a week or two, you wish you went bigger, I think you could work out something with Tom at PSA, but you'd need to call him and discuss it. I'm not saying he'd let you do a free upgrade within a month tryout, but I wouldn't be surprised if he did. Since you have the $2k budget in mind, it wouldn't hurt going with something a little bigger for a single sub. Take a look at the S1800, he's also taking opening orders on the new S1801; something I'd take at look at if I were you!

I definitely agree with you about consulting with Tom before I made a purchase, to learn what my options might be. Because the S1500 is lighter and easier to move than the more expensive models, it wouldn't be difficult to maneuver it into the four different positions I have available for a sub, as an experiment to discover where it sounds the best. If the results were overwhelmingly positive, I could find myself feeling the urge to upgrade to the S1801 sub you recommend.
I just noticed there is a thread on a different audio forum devoted exclusively to PSA Subwoofers. The thread was started in 2011 and has over 30,500 posts. (I don't mean to be dismissive, but in past visits to that forum I haven't been terribly impressed with the erudition exhibited in much of the commentary -- you have to slog through a lot of idle conjecture to read the scattered posts that have something genuinely insightful to say...)

 

[Henry Howards]

I have noticed that very few subs include balanced XLR ports, and I wonder why that is. I'm thinking it would be beneficial to connect a sub with a balanced cable...

 

[shadyJ]

The signal to noise ratio of informative posts is pretty good here, unlike many other forums. Audiophile BS does not thrive here.

There isn't any need for XLR cables unless you are making long cable runs or are in an electrically noisy environment. For typical home audio setups, there is no advantage.

 

[ATLAudio]

The PSA thread on AVS receives a lot of traffic, and is also a bit of a hangout with fellow PSA enthusiasts. They can get on tangents here and there but I try to keep up with it and a few other manufacture specific threads at AVS.

Balanced connections are only truly neecessary when going incredibly long lengths, like 200 feet across a stage, and ran next to 20 other cables next to it.

 

[Henry Howards]

The signal to noise ratio of informative posts is pretty good here, unlike many other forums. Audiophile BS does not thrive here.

Your metaphor is brilliant (and true).

There isn't any need for XLR cables unless you are making long cable runs or are in an electrically noisy environment. For typical home audio setups, there is no advantage.

I see. I was thinking balanced cable could help avoid ground loop hum (which would be really annoying with a subwoofer). I'm concluding that in most cases, the problem wouldn't be resolved by XLR connections anyway, and would need to be addressed through a different approach.

The PSA thread on AVS receives a lot of traffic, and is also a bit of a hangout with fellow PSA enthusiasts. They can get on tangents here and there but I try to keep up with it and a few other manufacturer specific threads at AVS.

Your equanimity is admirable. I could use more patience...

 

[KEW]

Remember the actual audibility of group delay; the lowest threshold for the audibility of group delay in bass frequencies I have ever heard about was 20 ms. There isn't a lot of research on this subject, but it is generally thought that group delay will be related to the cycle length of the individual frequencies, which is why group delay charts are typically shown the way they are. By the way, group delay graphs would be better for looking at the kind of behavior you are looking for. There the measured stored energy is separated from the frequency response, whereas in the spectrograms you are looking at, the separation is not as clear.

As you say, there is not so much research on the subject. I expect any effort to evaluate the minimum audible delay is done using a simple pulse and seeing what delays people can discriminate between. However, I am not so quick to dismiss the possibility of an audible effect from more complex and continuous signals (such as music has). But that is pure speculation on my part. My positions still stands if we say 20ms is not too bad; most (if not all) of the subs I am criticizing are well over 20ms!
Group delay graphs are fine by me. Unfortunately I do not see them for many subs that are pretty mainstream. Jman has targeted a lot of subs which are more commonly affordable. There is no group delay chart that I can find for the Rythmik E15HP which is a major example of a good sub to my ear. The PSA XS15se does have group delay charts and if you can point me to a ported sub which exhibits better behavior, that would be cool (but I bet it won't come cheap...if one exists)!

Furthermore, the original poster expressed an interest in deep frequency Pipe Organ music, and it may be that an elevated response in the 16 Hz to 30 Hz band may be preferred here. That would strengthen the sound of the fundamental, and the excess delay in such a low frequency isn't likely to matter so much.

Although it is up to the individual, I totally disagree with this. I have listened to many many BS speakers which often have "bumped up" bass (to sound more like full range). As I listen to a broad array of music, I always find places where the increase in one frequency band results in a perceived lack of detail in the adjacent band(s). I agree that it can sound better for specific music passages which do not involve much content in the adjacent band. However most organ music I know is well distributed across the frequency spectrum, and the OP said he enjoys organ music on occasion, not exclusively.
I consider it a simple truism that staying true to accurate reproduction is the most consistent and best route to good sound quality. I have certainly heard instances where artifice has resulted in an improvement in a song or even most music by one artist. However, invariably, that artifice comes out in other music in a way that is more offensive that the benefit of that artifice.

That said, I have to admit to being a total hypocrite when it comes to HT. As long as the dialect is clear, I can tolerate (or even enjoy) a lot of differing forms of artifice in the sound effects!

 

[KEW]

The problem is, what does that decay mean in those graphs? Where does the subwoofer group delay end and the room begin? How much of that is actual decay and how much of it is just due to the long wave cycles of low frequencies? Its just not clear in those spectrograms, as opposed to a group delay graph, where it is clear. What would the ideal response be in those spectrograms? I couldn't tell you, but I can tell you what it would be in a group delay chart.

With your experience, the ideal response should be understood! Remember, this is the same info as a waterfall chart! The ideal would be a uniform red right up against the y-axis (at x=0). If the signal lasts 1 ms then the theoretical ideal would be a vertical red/pink line 1 ms "thick" and everything else black!
Just as with a waterfall chart, the ideal would be a horizontal line across the back with nothing but emptiness on the "floor".
Of course these are ideals and no mechanical system (with concerns such as mass inertia and momentum) will be that responsive, but faster is better.

 

[shadyJ]

Although it is up to the individual, I totally disagree with this. I have listened to many many BS speakers which often have "bumped up" bass (to sound more like full range). As I listen to a broad array of music, I always find places where the increase in one frequency band results in a perceived lack of detail in the adjacent band(s). I agree that it can sound better for specific music passages which do not involve much content in the adjacent band. However most organ music I know is well distributed across the frequency spectrum, and the OP said he enjoys organ music on occasion, not exclusively.

I am talking about bass hot in the region around 20 Hz, not 100 Hz which is where you find elevated bass response in so many speakers. On the occasions that the massive pipe organs hit those extremely low notes, having them be a bit more powerful than what is recorded is not going to offend any pipe organ enthusiast.

As for the audibility of group delay in low frequencies, I have not heard of any rigorous scientific testing of delay perception below 500 Hz, and I have looked, through JAES archives, JASA archives, and IEEE archives (yes, they do publish research in audiology). The 20 ms thing is kind of a informal guideline within certain parts of the audio industry, and there is no research to back that up. Among the findings, it takes 10 ms to identify a 500 Hz tone correctly 90% of the time for healthy human hearing, and that is double the duration of the cycle.

Here is an informative graphic related to the subject:

"Pitch also depends on duration. A tone must last more than a minimum amount of time (~10-60ms, depending on frequency and intensity) in order to sound more than a 'click' and convey a clear sense of pitch (see the figure, below)."

What this says to me is that audiophiles have a far greater estimation of the acuity of their hearing than the reality.

 

[shadyJ]

With your experience, the ideal response should be understood! Remember, this is the same info as a waterfall chart! The ideal would be a uniform red right up against the y-axis (at x=0). If the signal lasts 1 ms then the theoretical ideal would be a vertical red/pink line 1 ms "thick" and everything else black!
Just as with a waterfall chart, the ideal would be a horizontal line across the back with nothing but emptiness on the "floor".
Of course these are ideals and no mechanical system (with concerns such as mass inertia and momentum) will be that responsive, but faster is better.

The problem is I am not sure of the timing they employ, and I'm not sure it is just like the waterfall charts you see in REW. If the signal is 1 ms showing a 1 ms red line the vertical axis, than what is a 20 Hz signal supposed to look like? A 50 ms 'wide' red line. But of course it depends on the timing of the input signal vs recorded signal. It looks to me what you are attributing to overhang is largely a matter of frequency response. Look how closely the red part of the graphs correspond to anything over 85 dB on the frequency response charts.

If you want to know overhang, this sort of thing is a lot more clear in group delay graphs. And let's not lose sight of the audibility of group delay vs the audibility of linear distortion (changes in frequency response). They are barely comparable; linear distortion has a far greater impact on perceived sound quality.

 

[KEW]

I am talking about bass hot in the region around 20 Hz, not 100 Hz which is where you find elevated bass response in so many speakers. On the occasions that the massive pipe organs hit those extremely low notes, having them be a bit more powerful than what is recorded is not going to offend any pipe organ enthusiast.

We will have to agree to disagree on this one. Based on my experience with treble and (admittedy upper) bass, an over-emphasis in the 20-30Hz range is likely to obscure any detail in the 30-50Hz range.

As for the audibility of group delay in low frequencies, I have not heard of any rigorous scientific testing of delay perception below 500 Hz, and I have looked, through JAES archives, JASA archives, and IEEE archives (yes, they do publish research in audiology). The 20 ms thing is kind of a informal guideline within certain parts of the audio industry, and there is no research to back that up. Among the findings, it takes 10 ms to identify a 500 Hz tone correctly 90% of the time for healthy human hearing, and that is double the duration of the cycle.

Here is an informative graphic related to the subject:

"Pitch also depends on duration. A tone must last more than a minimum amount of time (~10-60ms, depending on frequency and intensity) in order to sound more than a 'click' and convey a clear sense of pitch (see the figure, below)."

What this says to me is that audiophiles have a far greater estimation of the acuity of their hearing than the reality.

The duration of a tone to discern its pitch is interesting, but not the same as the duration of the decay to prevent music from sounding muddy.


I think part of what we are seeing in those graphs is the non-linear resonant response of a port. I don't know your background, but any port relies on resonance to do it's job. It takes so much energy for a resonance to become excited, and once it does, it will react disproportionately (IOW doubling the input will more than double the output).

I do believe what you are saying about having a greater estimation of acuity than reality, but until we have definitive data, I am going to look for the tightest subs I can find because I have experienced too many that have bloat among subs often recommended here. It may be that I do not have the proper cause-effect relationship and am on the wrong track looking at spectrograms or waterfall charts, but the experiental correlation is sound among the subs I have heard and looked at data for.

 

[KEW]

Lets keep it really really simple!
Here is impulse response for JL Audio E112 which did not sound good:

Here is Impulse response for XS15se which did sound good (to my ear):

I don't know if the above data reflects what I hear or is just coincidental, but the sound quality of the PSA XS15 is better than the JL to me. I'll welcome you speculation as to why that might be.

 

[KEW]

Henry,
Getting back to the essence of your post, If you do make it to visit your friends in Marietta and get over this way for a demonstration, I think the best demonstration I can offer is a comparison of PSA S1500 vs SVS PC12 Ultra. We could do this as dual or single subs.
I think you have read up on the S1500. If I was doing it over, I would choose the $900 15S after verifying with Tom V that there are no differences in SQ between the models (I am pretty sure there is not, but when the designer is so easily available, it makes sense to ask). So I believe the 15S is a viable solution for you and the S1500 is as close as I can demonstrate.
The SVS PC12 Plus goes for $1200 each, so is a little beyond your desired budget, but I believe anyone here who recommends a ported sub would be comfortable recommending that you buy the PC12 plus if the price was $900, and to my ear, there is little contest between them. They certainly fill the room with low frequencies for HT, but for music, they just can't disappear into the main speakers as they should! they keep saying "Hey! Over here...yep, that's me! You have a sub in your room!"

This is my comment after first hearing the PSA XS15se (I added the orange comment today to clarify):

I never heard the sub, which I see as a good thing. Bass was solid, and I know the sub did that, but the sub maintained these qualities (tight, impactful, and articulate) (from the speakers) without ever being it's own voice. That is perfectly what a good sub should do with music (and what the Rythmik E15HP's I normally listen to do, and what the JL Audio E112's fail to do)!

Oh, and please do understand! If you listen to these subs and decide the PC12 Plus is the sound you want in your room, I will probably be a bit incredulous, and ask you to listen to some specific passages of music (like some Steely Dan) that is very tight. However, knowing that you have heard both back to back is pretty much the final word, until that day comes, I will continue to be an aggressively proactive advocate for sealed designs which are not heavily EQ'ed when someone says music is their priority.

 

[Henry Howards]

Henry,
If you do make it over this way for a demonstration, I think the best I can offer is a comparison of PSA S1500 vs SVS PC12 Ultra. We could do this as dual or single subs.

Your offer to set up a demo is genuinely appreciated, though a timely trip to Georgia just doesn't seem to be in the cards for me. I'm actually curious to hear a comparison between the S1500 and the Hsu ULS-15 MK2, but I'm guessing that the PSA might be superior. (Looks like Hsu has lowered the price on the Rosewood model, which makes me wonder how seriously I may allow myself to be swayed by a purely cosmetic feature...)

So I believe the 15S is a viable solution for you and the S1500 is as close as I can demonstrate.

I imagine these models are essentially identical, it terms of what would be discernable to my hearing. For some (unscientific) reason I actually have a slight preference for the front-firing S1500. But the thought does occur to me that a down-firing sub might actually be better for creating more complex modes within a room. What is your opinion about this?

The SVS PC12 Plus just can't disappear into the main speakers as they should!

That is a deal-breaker for me. I'm already almost certain that I'm looking for a sealed subwoofer, as fine as that cylinder sub may be. Its 40" height also narrows down placement options to a single spot in my room, whereas a "cube" sub would allow me to experiment with as many as 5 different locations, a definite advantage.

I never heard the sub, which I see as a good thing. Bass was solid, and I know the sub did that, but the sub maintained these qualities (tight, impactful, and articulate) (from the speakers) without ever being its own voice.

That is EXACTLY what I want.

I will continue to be an aggressively proactive advocate for sealed designs which are not heavily EQ'ed when someone says music is their priority.

Your diligent advocacy is fine by me.

That said, I admit to being a total hypocrite when it comes to HT. As long as the dialog is clear, I can tolerate (or even enjoy) a lot of differing forms of artifice in the sound effects!

I can be even more extreme in this regard. Some movies have LFE that I find positively irritating, and it is not unusual for me to turn off the sound completely during those rumbustious scenes and just read the subtitles. I crave sonorous bass, rather than being bludgeoned by noise.

I would be interested in hearing your opinion on the servo control used in the Rythmik subs -- it makes a lot of sense to me. Do you believe it makes a significant contribution to improving the sound?
Thanks for all your advice -- I am finding it very helpful.