Stand-mounted vs. Floorstanding

[March Audio]

I invite you over for a listen, after the pandemic of course.

I'm going to play side 2 of The Dave Brubeck Quartet LP by Columbia Records "Time Further Out".

The drum track (first song on side 2) and following hand clapping track are going to make a believer out of you.

Then will play ELP's "Lucky Man", just the song not whole LP, followed up by playing both sides of Pink Floyd's Dark Side of the Moon, a master recording version.

The Goodbye Yellow Brick Road LP by E.J. might have a few worthy tracks, but bring some of your own stuff and put it though the paces.

You will be forced to reconsider your use of "never", never say never.

Mate, I have done it, got the t shirt and measured it. I don't need to to listen to your system. This is physics and the science of acoustics. There aren't special laws that apply in your room.

Have you measured the response in your room?

Have you ever actually heard a smooth low frequency response such as below to know what it's like?

 

[Karu]

Mains delay is not something that you should guess-adjust, you need to adjust it based on measurment. Typically it is in the range of 10-15ms but that really depends on DSP board in the sub.

How would you measure it? I do of course run also my passive mains via MiniDSP and then power amp after.

 

[kach22i]

Ok, let's say it's 5 ms. How exactly do you think you can shift sub response 5ms to the future by moving it around the room?

It's about a foot a millisecond, right?

So five feet?

http://www.gbaudio.co.uk/data/time.htm

Feet 20

delay in milliseconds 17.9

Approx. 20 FT = 20 milliseconds, I' mean 18 is close to 20 with a hand grenade, right?

So the amazing improvements I experience last night when I moved my stupidly large subwoofer 6-inches towards be, making it proud of the main speakers flanking it was just getting the big box out of the soundstage area a little more?

I can see that.

If I move my sub a whole five feet towards me I can maybe use it as a footstool, except it's too tall.

An under seat subwoofer location is looking like a great idea suddenly.

 

[kach22i]

Have you ever actually heard a smooth low frequency response such as below to know what it's like?

Are you inviting me over now?

I hope you live close.

 

[March Audio]

Ok, let's say it's 5 ms. How exactly do you think you can shift sub response 5ms to the future by moving it around the room?

You don't need to, you are not sensitive to this level of group delay at this low frequency.

Your main speakers will also have group delay increasing towards 100Hz and below.

Bear in mind that 1 cycle at 20Hz takes 50ms to put things into context.

 

[Xulonn]

You guys are turning me into a "waffle master" (in the U.S - to waffle is to not decide, e.g., to keep changing your decisions about something so that no clear decision is made.)

With my limited income, small listening room, and the cost of forwarding goods from the U.S. to Panama, a positive attribute of waffling is that it can dampen purchasing impulses, and hopefully help lead to a better final decision. Being long-since retired, and currently stuck at home due to COVID-19, I have even more time to explore audio possibilities.

As you can see from my system (listed in my signature lines), I have an excellent little pair of bookshelf speakers that are very bass limited. And if you have read my recent posts, I have been considering a pair of small towers and eventually adding a subwoofer or two. However, the discussion in this thread has convinced me to seriously consider a stand-mount plus sub(s) option.

One of the things I noticed recently is that the ultimate "sonic output" or "peak SPL" is actually listed in the specs for some loudspeakers, and that it varies - more than I had realized - as you go from mini bookshelf speakers to larger floor-standers. Looking at Wharfedale's matrix of speakers, at the lower end, I see the little D310 stand-mount at 86dB peak SPL, and at the other end, a peak SPL of 110dB for speakers like the much larger Diamond 250 tower.

My current sentiment has me considering the Wharfedale Evo 4.2's. I have owned and enjoyed speakers with both AMT and ribbon tweeters in the past. I once had the original ESS Heil AMT-1 speakers, and upgraded to the larger AMT-1T towers with transmission line woofers - until my ex-wife got them in a divorce. I also owned a pair of Apogee Centaurus Monitors with 4" ribbon tweeters for over 12 years before moving to Panama in 2012. The Wharfedale Evo 4.2's are a large (18" tall) three-way "bookshelf" speakers with AMT tweeters (pic below). They should do work nicely on 22"-24" stands. Although reviews of the Evo 4.2 are very good, most reviewers mention that they have limited bass in spite of their size. (The Evo 4.2's are rated at 105 peak SPL.)

And that gets me to the real problem - choosing the best subwoofer(s) for my room and music requirements. Movie sound tracks are secondary for me in my office/listening room, which is 10' x 16' plus a 4' x 7' "L" leg. Area is 188 sq.ft., and with a low 7.5' ceiling, volume is about 1,410 cu.ft. (40m^3)

Another other issue - a subject for which I cannot find any guidance, if there is a recommended low frequency limit for very small rooms. Is there anything wrong with going as low as 24Hz in my room?

As I researched subwoofers, I noticed that small, reasonably-priced subwoofers are offered by respected companies such as REL with its $400 Class-D powered T Zero. However, that highly-rated little unit with its 6-1/2" woofer has a -6dB point at only 38 Hz. Other the other REL T-series "music" type (vs. HT), Class-AB powered subwoofers, get pretty expensive as you go up in size. I ended up thinking that if I want bass down to 24Hz, I will buy a used KEF Kube 10b.

Two "stand speaker + sub" options are on my list now, and preferred one with the Evo 4.2's is a fair bit more expensive than the other. Although the probability for additional waffling is strong, my current plan is to start by buying a used, open box or other discounted KEF Kube 10b soon, and use it with my Paradigm Atom v6 monitors. Then i can replace the Atoms with Wharfedales in a few months

The two options:

1. A $1K pair of Wharfedale Evo 4.2 speakers and one $650 KEF Kube 10b subwoofer - Total cost ~ $1,000-1,200 as used, open box, etc.
2. A $250 pair of the much smaller (12.5" tall) Wharfedale D320 speakers, and the same KEF Kube 10b subwoofer.

 

[Siwel]

Don't fret.
Less volume, lower crossover.

Play with it.

There is a correct level, phase setting and crossover point for any given system. You may think of the crossover point as variable according to taste if you like but there is likely one point within a fairly limited range where a choice will be measurably optimal. Of course with LF energy, compromise is built into the puzzle.

There will still be an optimal combination of level and delay, phase angle, but it's worth experimenting with Xover frequencies within limits since any given situation will be unique to that combination. There may even be a preference for the slope of the crossover as well......12dB/octave, 24/dB p.o. etc. You can play with that.

But level and phase angle are correct at one particular setting for any given crossover frequency and sub/sat geometry in the room. You can physically put level wherever you like as a matter of preference but there is still a particular setting for level as well as delay and phase angle (if the crossover/processor is so featured) that will give the proper match and best measured response. It's pretty specific to any given arrangement and frequency, but there is an optimal setting. There are methods for finding it that have been covered in this thread (I think). That calibration should be your reference for the particular frequency and speaker geometry you created. If you get that right and start from there, you won't get lost because you will have a proper reference level unique to your combination. It doesn't take much to do it. I like to use an SPL meter because it identifies nulls better than I do. You need tones for each frequency you have in mind and by moving a few wires around and fiddling with a couple of knobs, you'll be in business. Read the Barry Ober "Sound Doctor" articles that were linked to by a previous contributor.

I think one of the hardest parts about my latest experiment has been figuring out where to put everything. For me, using my space wisely is the most complex part of getting close to what I want. I find it more complex and clearly a ton more work than say, setting up a crossover, or bothering with delays (which I consider not worth the fuss with my current rig).

If there is a downside to big speakers it is that they are hard to move around for placement and they generally need space once they get there. If you can deal with that, then bring the good stuff, big and tall is great. I like them to sound wall to wall and eight feet tall. Little speakers don't do that like the heavyweights.

 

[QMuse]

You don't need to, you are not sensitive to this level of group delay at this low frequency.

Your main speakers will also have group delay increasing towards 100Hz and below.

Bear in mind that 1 cycle at 20Hz takes 50ms to put things into context.

My point here was that you cannot shift things in time by moving the

You don't need to, you are not sensitive to this level of group delay at this low frequency.

Your main speakers will also have group delay increasing towards 100Hz and below.

Bear in mind that 1 cycle at 20Hz takes 50ms to put things into context.

When you are listening to one speaker which phases shifts continuously in LF area that is true, but in the XO area where you have 2mains and sub playing the same tones and sub is delayed by 5ms or more you will hear it. That is why all AVRs have delay settings for multiple speakers setup.

 

[QMuse]

How would you measure it? I do of course run also my passive mains via MiniDSP and then power amp after.

You can meaasure it with REW with sweeps which include timing reference signal. It has been described in detail somehere on this forum, just search for it. The idea is to measure (for example) left main and sub while right main plays timing reference signal. Substracting those 2 delays give you delay between left main and sub.

 

[QMuse]

You guys are turning me into a "waffle master" (in the U.S - to waffle is to not decide, e.g., to keep changing your decisions about something so that no clear decision is made.)

With my limited income, small listening room, and the cost of forwarding goods from the U.S. to Panama, a positive attribute of waffling is that it can dampen purchasing impulses, and hopefully help lead to a better final decision. Being long-since retired, and currently stuck at home due to COVID-19, I have even more time to explore audio possibilities.

As you can see from my system (listed in my signature lines), I have an excellent little pair of bookshelf speakers that are very bass limited. And if you have read my recent posts, I have been considering a pair of small towers and eventually adding a subwoofer or two. However, the discussion in this thread has convinced me to seriously consider a stand-mount plus sub(s) option.

One of the things I noticed recently is that the ultimate "sonic output" or "peak SPL" is actually listed in the specs for some loudspeakers, and that it varies - more than I had realized - as you go from mini bookshelf speakers to larger floor-standers. Looking at Wharfedale's matrix of speakers, at the lower end, I see the little D310 stand-mount at 86dB peak SPL, and at the other end, a peak SPL of 110dB for speakers like the much larger Diamond 250 tower.

My current sentiment has me considering the Wharfedale Evo 4.2's. I have owned and enjoyed speakers with both AMT and ribbon tweeters in the past. I once had the original ESS Heil AMT-1 speakers, and upgraded to the larger AMT-1T towers with transmission line woofers - until my ex-wife got them in a divorce. I also owned a pair of Apogee Centaurus Monitors with 4" ribbon tweeters for over 12 years before moving to Panama in 2012. The Wharfedale Evo 4.2's are a large (18" tall) three-way "bookshelf" speakers with AMT tweeters (pic below). They should do work nicely on 22"-24" stands. Although reviews of the Evo 4.2 are very good, most reviewers mention that they have limited bass in spite of their size. (The Evo 4.2's are rated at 105 peak SPL.)

And that gets me to the real problem - choosing the best subwoofer(s) for my room and music requirements. Movie sound tracks are secondary for me in my office/listening room, which is 10' x 16' plus a 4' x 7' "L" leg. Area is 188 sq.ft., and with a low 7.5' ceiling, volume is about 1,410 cu.ft. (40m^3)

Another other issue - a subject for which I cannot find any guidance, if there is a recommended low frequency limit for very small rooms. Is there anything wrong with going as low as 24Hz in my room?

As I researched subwoofers, I noticed that small, reasonably-priced subwoofers are offered by respected companies such as REL with its $400 Class-D powered T Zero. However, that highly-rated little unit with its 6-1/2" woofer has a -6dB point at only 38 Hz. Other the other REL T-series "music" type (vs. HT), Class-AB powered subwoofers, get pretty expensive as you go up in size. I ended up thinking that if I want bass down to 24Hz, I will buy a used KEF Kube 10b.

Two "stand speaker + sub" options are on my list now, and preferred one with the Evo 4.2's is a fair bit more expensive than the other. Although the probability for additional waffling is strong, my current plan is to start by buying a used, open box or other discounted KEF Kube 10b soon, and use it with my Paradigm Atom v6 monitors. Then i can replace the Atoms with Wharfedales in a few months

The two options:

1. A $1K pair of Wharfedale Evo 4.2 speakers and one $650 KEF Kube 10b subwoofer - Total cost ~ $1,000-1,200 as used, open box, etc.
2. A $250 pair of the much smaller (12.5" tall) Wharfedale D320 speakers, and the same KEF Kube 10b subwoofer.

View attachment 55038

Well, you know the answer to that dilemma so go for it if you can afford it.

Btw, I had a chance to EQ Cube 10b for a friend, that is a fine peace of machinery. Detailed test with measurements here (it's in German, but Google translate does a decent job with translation).

 

[QMuse]

It's about a foot a millisecond, right?

So five feet?

http://www.gbaudio.co.uk/data/time.htm


Approx. 20 FT = 20 milliseconds, I' mean 18 is close to 20 with a hand grenade, right?

So the amazing improvements I experience last night when I moved my stupidly large subwoofer 6-inches towards be, making it proud of the main speakers flanking it was just getting the big box out of the soundstage area a little more?

I can see that.

If I move my sub a whole five feet towards me I can maybe use it as a footstool, except it's too tall.

An under seat subwoofer location is looking like a great idea suddenly.

Sure, moving a sub 20ft closer to your seat relative to the mains would do the job. You can aslo sit on it for additional excitiment.

 

[Xulonn]

Btw, I had a chance to EQ Cube 10b for a friend, that is a fine peace of machinery.

That simple line from an ASR member whose judgement I trust after reading many posts is a stronger recommendation to me than accolades for it from a subjectivist reviewer trying to not offend the hand that feeds him.

And thank you for the link - autotranslate in Chrome Canary did a good job with the translation.

I will look for a used or refurbished KEF Kube 10b after the coronavirus pandemic finishes here in Panama.

 

[March Audio]

My point here was that you cannot shift things in time by moving the


When you are listening to one speaker which phases shifts continuously in LF area that is true, but in the XO area where you have 2mains and sub playing the same tones and sub is delayed by 5ms or more you will hear it. That is why all AVRs have delay settings for multiple speakers setup.

You won't. As I said you are not sensitive to this level of group delay at these low frequencies.

If you are talking about phase matching at crossover to get even amplitude then that's a different thing.

 

[QMuse]

If you are talking about phase matching at crossover to get even amplitude then that's a different thing.

Well of course I am. Folks should be clear that when they are integrating their subs with mains they are actually creating a crossover, and crossover should ensure not only smooth FR but also smooth phase response. So, if you have 5ms difference between sub and mains at XO point of say 80Hz than that would certainly be an audible issue.

That scenario cannot possibly be compared to a smooth phase drift of a woofer at LF where 5ms of GD at 80Hz is definitely not an issue.

 

[March Audio]

Well of course I am. Folks should be clear that when they are integrating their subs with mains they are actually creating a crossover, and crossover should ensure not only smooth FR but also smooth phase response. So, if you have 5ms difference between sub and mains at XO point of say 80Hz than that would certainly be an audible issue.

That scenario cannot possibly be compared to a smooth phase drift of a woofer at LF where 5ms of GD at 80Hz is definitely not an issue.

Why "of course"?

Firstly it's not what kach was referring to. Secondly it doesn't automatically follow that you are going to have a massive dip that is audible.

You have to put "5ms" in the context of the wavelength. Also don't forget that your main speakers also start exhibiting group delay at these frequencies.

 

[QMuse]

Why "of course"?

I said "of course" because discussion was about integrating sub with mains which is about XO design. I didn't mean it to sound hursh, though.

You have to put "5ms" in the context of the wavelength. Also don't forget that your main speakers also start exhibiting group delay at these frequencies.

So does the sub. But when doing XO design between 2 drivers (in this case between sub driver and woffer in mains) it is not about GD - it is about getting the smooth phase hand-over at XO point between 2 drivers.

GD is simply a derivation of phase response vs frequency. If you get the phase curve handover smooth at XO by fixing the delay and correcting the phase of the sub and woofer in mains to be slope matched GD curve of total phase response will remain smooth.

 

[Frank Dernie]

So the amazing improvements I experience last night when I moved my stupidly large subwoofer 6-inches towards be, making it proud of the main speakers flanking it was just getting the big box out of the soundstage area a little more?

A rectangular room has 3 main modes which will be excited plus their harmonics.
In the same way as the tone of a string varies depending on where you pluck/bow it the extent to which these main modes and their harmonics will be excited depends on precisely where in the room the subwoofer is located.
It may well be that moving your sub 6" changes the excitation of one of the harmonics a LOT.
Before cheap DSP compensation positioning the bass units to minimise the excitation of the modes and their harmonics was the only way to make the bass reasonably even in a room.

 

[March Audio]

I said "of course" because discussion was about integrating sub with mains which is about XO design. I didn't mean it to sound hursh, though.



So does the sub. But when doing XO design between 2 drivers (in this case between sub driver and woffer in mains) it is not about GD - it is about getting the smooth phase hand-over at XO point between 2 drivers.

GD is simply a derivation of phase response vs frequency. If you get the phase curve handover smooth at XO by fixing the delay and correcting the phase of the sub and woofer in mains to be slope matched GD curve of total phase response will remain smooth.

No the point of discussion was about kachis hand waving regarding "out of time energy"

Yes I'm perfectly aware of this. The point you are missing is that the mains speakers phase and group delay is shifting too. You can't simply distill this into "5ms of group delay equals disaster".

 

[QMuse]

Yes I'm perfectly aware of this. The point you are missing is that the mains speakers phase and group delay is shifting too. You can't simy distill this into "5ms of group delay equals disaster".

First of all I am speaking about 5ms of delay in impulse response between mains and sub. Why are you putting an equal sign between that and 5ms in GD???

 

[March Audio]

First of all I am speaking about 5ms of delay in impulse response between mains and sub. Why are you putting an equal sign between that and 5ms in GD???

I'm not.

You do realise that the vast majority of speakers have delays between woofer and tweeter and yet they can still sum at the xo and sound fine.