Tower with good bass extension vs. stand-mount with a sub?

[eddantes]

Sub+standmounts are probably better with all the caveats mentioned above. Wether Kef or Revels will depend if you're in NA or Europe. As for sub - not sure you need to go that upscale as KC62, and again the brand will depend on your location as above.

As for sub placement and configuration - it doesn't need to be as hard or complicated as everyone here suggests to get to a "reasonable" end state. What works for me (right or wrong):

• Use the standard 80hz xover
• Use a room mode claculator to ballpark a location where a sub will least excite modes ~80hz or higher
• Ensure sub is in-phase - not that hard to do by ear and a tone
• Set sub volume low enough - that it doesn't seem to be contributing much if at all...
• Spend some time listening... and raise sub volume a notch
• Spend some time listening... and raise sub volume a notch
• Spend some time listening... if sub contributes too much - roll back 1/2 of last adjustment

In the end - how much your sub contributes is a preference, no matter what anyone will tell you. The goal of the above exercise, is to edge towards your preference without wildly exceeding it and then find yourself oscilating between one type of frustration or another.

Yes you will still have room modes that affect the sound in ways you'd rather they didn't. Yes, you can improve things with a microphone and software - but you will need to spend time learning, or buy something that has Dirac live and let it handle the room for you. You will still need to start somewhere and if you start at a reasonble point (like I believe my advice offers) then measurements and room management will be a bit easier too.

Anyways - this is my experience - others may disagree.

 

[Power Pop 23]

You mean that the gain/crossover settings available via a sub give more tuning options?

I should also have mentioned, perhaps, that I intend to integrate Dirac room correction into the system (MiniDSP SHD, or similar)

With the use of Dirac, I vote for the Polks

I listen mostly to music......

I deployed Dirac for standalone computer using a pair of Revel M16's and a Hsu STF-2 subwoofer. I found Dirac had to do a lot of 'correction' to smooth out the hand off of frequencies between the Revels and the Hsu subwoofer. I swapped out the Revels for a pair of KEF LS50 Meta's and found a similar result. I dragged a pair of Polk ES60 tower loudspeakers into my primary listening space and found Dirac had less work to do to correct the Polk ES60 tower loudspeakers - sans Hsu - in 2.0 setup.

It may be expectation bias, but I prefer the size of the imaging I perceive listening to the Polk ES60's compared to the the Revels or KEFs with my Hsu subwoofer

Consider reading reviews of tower loudspeakers recommended by Amir. In many of the reviews, Amir speaks to the spatial qualities he perceives listening to a floor-standing loudspeaker compared to a standmount loudspeaker.

 

[Open Mind Audio]

Someone needs to give some love to the big guns! It's true that standmounts with subs will give you more flexibility to achieve smooth bass frequencies by moving your one or two subs to the optimal location(s), totally indepenent of the mains, and then using room correction if necessary. (IMO nothing beats placement as a method of room correction.) Another plus for this approach is you can start with one sub and add more later.

But tower speakers are awesome, and with proper or lucky placement, you can get excellent bass through towers without a sub. That minimizes the amount of space needed for speakers, which can be very important for things like, say, marital relations. I listen to KEF LS 60s in one room without subs and Goldenear Triton Ones in the home theater room, also without subs. These speakers have good low range and I never miss having a sub. It's tricky to place the Triton Ones -- you are essentially placing two small left-right subwoofers in the same spot as your mains, and you have to tinker a lot to get that right (to avoid nulls, etc.).

In sum, if you can get full range or close to full range towers that have good bass at the sound levels you like, and if you have the ability to experiment with where you put the mains, you can be extremely happy with just towers vs standmounts and sub.

Both options are great IMO.

 

[terryforsythe]

One word answer: Yes

There are other benefits to adding a sub:

- removes low frequencies from the woofer, so less woofer excursion and therefore less distortion
- increases apparent amplifier power by removing low impedance regions of the frequency response from the mains
- if your mains are ported, you can probably seal up that port. I hate ports.
- subwoofers and proper bass seem to improve the spatiality of the sound.

The difficulties of subwoofer integration should again not be understated. Unless the OP is prepared to DSP and do measurements, he should forget the idea of adding a subwoofer.

I'll add my experience for context. Previously I used my subwoofer using a first order high pass filter on the speaker amplifier and the subwoofer's internal crossover. My subwoofer has a user adjustable crossover frequency, but does not have variable time delay nor user adjustable equalization. My bass never sounded right. Sure, I could get the walls to shake, but the frequency response was not good.

I added a miniDSP, which provides a proper active crossover, parametric equalization and Dirac Live. That transformed my system for the better.

I also plugged my speaker ports, crossing over around 100 Hz since the stand mount speakers don't play as low with the ports plugged. For my system that improved the transition between my stand mount speakers and subwoofer, clearly improving my bass response, and lowering harmonic distortion. However, recently I was communicating with someone in another thread and he stated that in his system he was able to get a smoother bass response by leaving the ports unplugged and crossing over at 60 Hz. I don't think he had much in the way of DSP for parametric equalization, but he did adjust his subwoofer time delay and his frequency response plot did not look too bad.

 

[Keith_W]

I don't think he had much in the way of DSP for parametric equalization, but he did adjust his subwoofer time delay and his frequency response plot did not look too bad.

There is so much more to subwoofer integration than a frequency response plot If you want to read about how much I have suffered, take a look at my system thread, especially the last few pages which illustrate my ongoing struggles with my subwoofers. It really is not for the faint hearted.

However, as has already been said - don't let perfection be the enemy of good.

 

[GaryY]

This is ported vs sealed my left main in (ugly) room without DSP. It doens't look I can get some advantage.

 

[rynberg]

Dosn't plugging the port change the woofer response, as in adding a peak or dip above the cut off? Arnt you changing the loading of the woofers? I have some f226's and a sub and am thinking about try that.

In my opinion, there is almost zero reason to plug the ports on a well-designed freestanding speaker when using a subwoofer, particularly when the port is tuned low like on your F226. For one thing, the response is already down 8 dB+ at the port tuning if you are crossing over at 80 Hz. Secondly, any lumpiness that still resulted even with the decreased output is easily addressed as part of the room correction.

What makes you even consider this in your system?

 

[terryforsythe]

This is ported vs sealed my left main in (ugly) room without DSP. It doens't look I can get some advantage.

Measure the phase of the two setups, and compare them to a phase plot of your subwoofer.

You can use variable time delay to get the subwoofer and speakers in phase at the listening position precisely at the crossover frequency, but the slopes of their phase responses will be different. Thus, they will not be kept precisely in phase in the transition region immediately above and below that frequency. In my speakers, plugging the ports along with adjusting the time delay helped to reduce the phasing differences in the transition region. Your system is different, though, and your milage may vary.

 

[rynberg]

If I had to choose between towers like the Polk R700 and a set of bookshelves+subwoofer, it would be the latter 99 times out of 100. I've never understood how people can be happy with bass response that's rolling off strongly by 40 Hz (open E on a bass is 41 Hz!). The R700 has better extension than most and might be adequate in a small room, but then you have the separate issue of not being able to control the bass response in the room as easily as with a subwoofer.

The main limitations of the bookshelf+subwoofer configuration are (1) output at mid-bass frequencies -- the bookshelf just can't generate enough clean output at 80-100 Hz to keep up with the subwoofer; and (2) the off-axis directivity issues with a 2-way vs a 3-way. Best of all worlds would be a 3-way tower with a subwoofer.

 

[terryforsythe]

the bookshelf just can't generate enough clean output at 80-100 Hz to keep up with the subwoofer

I crossed mine over at 100 Hz. In my miniDSP I used gain control and DSP to tune. It sounds very, very good.

 

[rynberg]

I crossed mine over at 100 Hz. In my miniDSP I used gain control and DSP to tune. It sounds very, very good.

I believe you! Still, a ~6 to 6.5-inch driver can only do so much. My system does both music and home theater and a single 6.5 inch driver covering to 80 Hz becomes the limiting factor. In my experience, a potential problem with crossing over higher than 80 Hz is localization of the sub, which forces one to place the sub between the L+R, something I cannot do in my current living space.

 

[rdenney]

Give me towers any day. (My towers are Revel F12's--two 8" woofers, 5.5" midrange, and tweeter, with rear-facing port that I've never heard chuffing.)

At least to start with.

All those who appeal to the ease of modern tools for placement of speakers and subwoofers must be lucky to have rooms that are rectangular and subject to no external controls. My main listening space doesn't have those features at all. The ceiling of my space is sloped at an 8:12 pitch leading up to a second-story loft. And placement is constrained by the open concept of our house--open walkways, stairs, and lots of windows limit wall space, and also limit where the piano can go, which limits everything else.

Just try to figure out how to calculate modes and sub locations in this room using an online tool:

There is also a big issue of use cases. The need for a subwoofer for home theater is significantly different than for listening to music, and even if limited to music, it varies by genre. I don't listen to thump-thump-thump-thump pop music so I don't really need to shake the wife's collectibles shelves. I can still feel my blood pressure rise when listening to the bass synthesizer sounds on Rick Wakeman (and, for that matter, Philip Glass) recordings, and those go lower with more power than any acoustic instruments, or even bass guitar.

And speaking of wives...(edited)

Yes, I have a null in the right channel at about 70 Hz or a bit above, plus a couple of smaller nulls in the left channel at 55 and 90 Hz.

(Image replaced on edit--didn't link the latest.)

There is, like, one possible sub location in that room, and the chance of it being the right location to fill in that null in that one channel is pretty small, it seems to me. But the probability of it fighting my main speakers is much greater. I'd want a crossover a lot lower than 80 Hz, for one thing, but the null is just at too high a frequency.

For our home theater system, I have a 5.1 arrangement and I let the Yamaha AVR adjust everything, which it did more than well enough for watching TV and movies. That subwoofer hides behind the 50" plasma display, and is quite close to a corner of the room. I've never dared to subject that system to REW--that could undermine my current satisfaction with it for that purpose. That room presents far worse challenges for speaker placement compared to the room above, and is subject to spousal approval to an even greater extent.

Rick "heard complaints this morning about the five tubas scattered around the space above" Denney

 

[terryforsythe]

a potential problem with crossing over higher than 80 Hz is localization of the sub

At 100 Hz I don't have that issue - the wavelength at 100 Hz is 3.43 m, which is too long for me to be able to localize, especially when music is playing from the speakers. I am using very steep crossover slopes, so that helps.

 

[rdenney]

At 100 Hz I don't have that issue - the wavelength at 100 Hz is 3.43 m, which is too long for me to be able to localize, especially when music is playing from the speakers. I am using very steep crossover slopes, so that helps.

That assumes the sub is producing no audible harmonic distortion, which isn't necessarily a given for systems played loudly or with source material that includes a lot of percussive peaks at low frequencies. It doesn't take much harmonic distortion to reach up into the localizable spectrum at audible levels, it seems to me.

Rick "thinking 1% THD in a sub at higher listening levels is on the good end of the scale" Denney

 

[terryforsythe]

That assumes the sub is producing no audible harmonic distortion

The harmonic distortion of my subwoofer at listening levels is pretty low. At 80 dB (at listening position), 100 Hz, the total harmonic distortion is around -60 dB. (Where the plots turn gray they are in the noise floor).

 

[Rotor]

If I had to choose between towers like the Polk R700 and a set of bookshelves+subwoofer, it would be the latter 99 times out of 100. I've never understood how people can be happy with bass response that's rolling off strongly by 40 Hz (open E on a bass is 41 Hz!). The R700 has better extension than most and might be adequate in a small room, but then you have the separate issue of not being able to control the bass response in the room as easily as with a subwoofer.

The main limitations of the bookshelf+subwoofer configuration are (1) output at mid-bass frequencies -- the bookshelf just can't generate enough clean output at 80-100 Hz to keep up with the subwoofer; and (2) the off-axis directivity issues with a 2-way vs a 3-way. Best of all worlds would be a 3-way tower with a subwoofer.

Interesting. Because one of the additional thoughts I am having is whether something like the LS50 Meta is enough with a sub, or something like the R3 (with the additional driver and better lower frequency response) still adds value. Seems like the later, in your view.

 

[rdenney]

The harmonic distortion of my subwoofer at listening levels is pretty low. At 80 dB, 100 Hz, the total harmonic distortion is around -60 dB. (Where the plots turn gray they are in the noise floor).

View attachment 354838

Looks to me like you have frequencies that distort to 1% below 30 Hz, but it looks better than most I've seen. At this and higher listening levels, not many subs are that clean, even when they are highly regarded. Of course, tower speaker woofers will also distort at those frequencies when played loudly, and probably worse, but they aren't facing the problem of being localizable.

And then there's the issue of needing 2-4 subs for really smoothing out those room modes, which just adds dimensions to the problems of living with them.

The subs that really do well in this regard are BIG, especially when paired with speakers that have decent bass response already. (One I looked at was 22x22x18 inches, which is pretty darn big especially if you have multiples of them.)

Lots of people asking this question are looking at tiny stand-mount speakers with single 5 or 6" woofers, and their use of a sub is really to just add a proper woofer to their system. Towers with proper woofers (and my Revels' pair of 8" woofers has about the same radiating area as a single 12" woofer) usually have good extension at least down into the 30's. The folks asking these questions aren't usually trying to get serious content at 20 Hz--they are just trying to get real power at 40-50 Hz. But that's a different objective than taming room modes.

(If they had real power at 20 Hz, what will be localizable are all the tchotchkes on the shelves and picture frames on the walls vibrating noisily. Ask me how I know.)

Rick "who spent half an hour looking for a noisy vibration on a tuba that turned out to be the picture on the wall behind the playing position" Denney

 

[terryforsythe]

Looks to me like you have frequencies that distort to 1% below 30 Hz, but it looks better than most I've seen.

It is a 26+ year old Velodyne, though the plate amplifier was replaced in 2007 (the original amplifier developed a low level hum after about 10 years or so).

The plot was measured at the listening position, which is over 4 m from the subwoofer location. At 1 m the SPL is higher.

Rick "who spent half an hour looking for a noisy vibration on a tuba that turned out to be the picture on the wall behind the playing position"

I feel the pain on that one. When I run frequency sweeps there are some things in the room that rattle. I usually don't notice them when listening to music, though.

 

[waynel]

Using subs is usually better as it allows placement flexibility while avoiding SBIR but to get good results with subs proper bass management with high pass filtered mains and room correction are necessary. Also, btw the Kef subs are both poor value and poor performing, I recommend you look at Rythmik, PSA, Arendal, and SVS and get a pair if possible.

 

[slaweks]

You are really not going to like my answer.

For ultimate quality, nothing beats a sub. The main reason why is because the requirements for speaker position for best bass and best spatial qualities are different. For spatial qualities, you want an equilateral triangle with sufficient distance from room boundaries to delay reflections as much as possible. For best bass, you want the speakers near room boundaries for more reinforcement. Obviously, if you have a one speaker doing everything, it is difficult to position them where they will simultaneously deliver the best spatial response and the best bass response. Using a subwoofer gives you this flexibility.

However, as Amir points out, subwoofers are for advanced users. Having gone through subwoofer problems myself, I have to agree. Integrating a subwoofer is not easy, and I would say it is impossible to integrate a subwoofer properly without DSP. Even with DSP, it can be a bit of a headache.

Integrating subwoofer is not that difficult if you use Dirac or something similar.