speaker match for 282/200

I am not sure Huge, placing a subwoofer in a corner is often, but not always recommended, and seems to vary on the design of the subwoofer and whether it has a downward facing driver or a lateral driver,  as it produces the most dense standing waves and reduces the possibilities of nulls and excites all possible room nodes in a circular pattern out from the speaker. Having two subwoofers in each corner would be even better to get an averaging effect. 

Placing a subwoofer near to the speaker plane close to a wall and within the speakers is an alternate..

But the whole sub placement in a typical living space is a compromise where there are usually no bass traps - hence why a DSP can be useful... and I have ordered a miniDSP to play with

With regard to to your central placement scenario- according to my calculations that is equally advantageous and as fraught as a lateral firing subwoofer in a corner -  other than it would  give a different set of dimensions to play with for a given room - albeit they would be harmonically related

Simon, I've seen the recommendation for placing a sub in the corner, but I've never seen any modelling that indicates this to be the best position for an even response.  The usual reason for recommending the corner is that "it's most efficient" or "it sounds louder that way".  This is true, but that loudness comes at the expense of control and is most often a pyrrhic victory.  Placing two subs in opposite corners usually doesn't alleviate the problem of excessively exciting the primary room modes as both subs behave the same way.

A real alternate to center placement is to position it at a point on the golden ratio, but even this couples to the primary modes more than is desirable.

In practice using subs, I haven't found a problem with nulls, as they tend to occur at frequencies higher than the sub / main speaker crossover region, whereas exciting the primary room resonances is almost always a problem.  Destructive interference patterns created between the main speakers and the sub in the crossover region can be a problem, but if the phase relationship / group delays are aligned for the primary listening zone, then these problems won't actually be heard when listening seriously as they occur at different places in the room.

Incidentally the direction in which a sub fires makes no significant difference to the far field sound distribution as they are pressure mode devices, not directional.

Also don't forget that unless efficient bass traps are used the room will normally be underdamped at it's primary resonant frequencies and hence not only will these frequencies be much louder, but the decay will be much slower, causing the 'bass overhang' effect.

Simon-in-Suffolk posted:

Ok, calling those with PMCs, I am not sure if it's the 25.21 I am auditioning not being full run in or not, but on choral music with strong treble soprano I hear a very slight coarseness to the upper treble in the voices ... anyone else heard that... having been a chorister in my early youth, I notice these things unfortunately..

Worth trying the Fact range.  The tweeter is more extended and to my ears not harsh.  This series also has similar openess/transparency/clarity of the ATC SCM19 and 40.

Fact 3 works amazingly well in my system and room.  You can alter treble and bass response too in this range-makes positioning a lot less critical.

There are now subs, too.

Downside - price (I was lucky to find Fact 3 and matching stands at less than the SCM19 price with 23 years warranty remaining) 

Jude ;-)

 

Thanks Jude, I have decided to stay with my ATCs for now, they really are the speakers to beat ... I am looking at a sub now to fill in the lower octave in my listening room.. I did discover with my recent 'investigation' of demoing other speakers (always keep an open mind) I am missing some useful info down there with my 19s

Simon-in-Suffolk posted:

Thanks Jude, I have decided to stay with my ATCs for now, they really are the speakers to beat ... I am looking at a sub now to fill in the lower octave in my listening room.. I did discover with my recent 'investigation' of demoing other speakers (always keep an open mind) I am missing some useful info down there with my 19s

Difficult to match the 19s.  I would have ended up with these if I didn't come across the Fact 3.

BTW, I got it wrong re Fact series subs- no subs (PMC launched centre speakers in this range earlier this year).

Hope the hunt for a sub ends happily - worth giving REL a try.

Simon-in-Suffolk posted:

... I am looking at a sub now to fill in the lower octave in my listening room ...

I'm not sure where I'd put a sub but would be interested in any further findings. Although we tried other more bass oriented speakers and still preferred the ATC SCM19 in our room, I also want to keep an open mind.

Huge posted:

Incidentally the direction in which a sub fires makes no significant difference to the far field sound distribution as they are pressure mode devices, not directional.

Indeed, but at the frequencies we are talking and for many domestic rooms we are talking near field aren't we? Regarding bass traps - irregular shaped rooms help here as well..

Simon,

When the speaker is driving a void at less than about 3λ-4λ, the whole concept of near field vs far field breaks down.  The whole room is driven to almost the same energy density (interference fringes excepted), since the sub's pressure output is essentially time average acoustically coupled to the entire room, not just to the air immediately in front of it.  The pressure behind a sub is almost identical to the pressure in front at the same distance from the cone, in effect the sub is a behaving as an omnidirectional pressure source, not a device that emits a 'beam' of sound.  The combined effect of these is that sound from a sub is always multiply reflected back and forth around the whole room, hence the situation in the whole room more closely approximates to far field than near field.

In practice I find this to be true: the perceived bass volume around my room varies much less than the perceived mid-range volume.

It also makes no significant difference to the bass level or resonance patterns no matter which way I orient the sub (however turning it to closely face the wall slightly alters the distribution of 2nd and 3rd harmonic distortions).

Jude2012 posted:
Simon-in-Suffolk posted:

Ok, calling those with PMCs, I am not sure if it's the 25.21 I am auditioning not being full run in or not, but on choral music with strong treble soprano I hear a very slight coarseness to the upper treble in the voices ... anyone else heard that... having been a chorister in my early youth, I notice these things unfortunately..

Worth trying the Fact range.  The tweeter is more extended and to my ears not harsh.  This series also has similar openess/transparency/clarity of the ATC SCM19 and 40.

Fact 3 works amazingly well in my system and room.  You can alter treble and bass response too in this range-makes positioning a lot less critical.

There are now subs, too.

Downside - price (I was lucky to find Fact 3 and matching stands at less than the SCM19 price with 23 years warranty remaining) 

Jude ;-)

 

Fact 12s sound great (to my ears), with full bass extension belying their small size, also 'tiltable' to boost or cut bass slightly to help tailor to different rooms. My only reservation was in a rectangular room firing across the width the soundstage seemed a little compressed, although that wasn't evident in a different (squarer) room.

Huge posted:

For me there are three reasons for using a sub

1)  The position of the main speakers can be fully optimised for upper bass and midrange response without having to compromise the position to get a more even low-bass to mid-bass response.

2)  The sub can be positioned to optimise the evenness of the bass response without having to compromise the position to get an even midrange response.

3)  It enables a DSP to be used selectively on the lower bass range (leaving the critical midrange undisturbed), to ameliorate room resonances. This can then be done without detracting from the quality of the midrange (where the most critical and finest of the musical detail can be heard - or lost!).

Huge, if I am not mistaken, you are using a single subwoofer in your system. Would appreciate if you can elaborate on the effectiveness of using a single sub rather than a pair of subs which is the recommended setup for a stereo system. In "Get Better Sound" by Jim Smith,  the use of a single sub in a stereo system is not recommended.

I ask this question as my PMC TLE-1 sub has been lying around for ages after it was retired from the Home Theater setup many years ago. I was thinking if I should put it to some good use sometime, or retire it.

Any insight would be appreciated.

Simon-in-Suffolk posted:

 The SCM 19 mk2 I have currently work quite well at low volume, although the bass extension semis to contract a little.

It is a bit worrying that you find the bass on the SCM 19 Mk2 to be deficient as I am looking at the SCM 11. May I ask, how big is your listening room and how far away are you sitting from the speakers?

ryder. posted:
Huge posted:

For me there are three reasons for using a sub

1)  The position of the main speakers can be fully optimised for upper bass and midrange response without having to compromise the position to get a more even low-bass to mid-bass response.

2)  The sub can be positioned to optimise the evenness of the bass response without having to compromise the position to get an even midrange response.

3)  It enables a DSP to be used selectively on the lower bass range (leaving the critical midrange undisturbed), to ameliorate room resonances. This can then be done without detracting from the quality of the midrange (where the most critical and finest of the musical detail can be heard - or lost!).

Huge, if I am not mistaken, you are using a single subwoofer in your system. Would appreciate if you can elaborate on the effectiveness of using a single sub rather than a pair of subs which is the recommended setup for a stereo system. In "Get Better Sound" by Jim Smith,  the use of a single sub in a stereo system is not recommended.

I ask this question as my PMC TLE-1 sub has been lying around for ages after it was retired from the Home Theater setup many years ago. I was thinking if I should put it to some good use sometime, or retire it.

Any insight would be appreciated.

Provided the integration of the sub to the main speakers is arranged correctly (crossover frequency, amplitude, cut rates and phase - N.B. true phase, not just 0°/180°) then use of a single sub is fine, since for bass frequencies you locate sounds by their harmonicas, not the fundamental.

To get the phase integration of a sub right usually means having a shorter distance to the listener for the sub than for the main speakers to compensate for the group delay of the sub's amplifier.  Using two subs located beside the main speaker is usually a far more compromised setup as then it's almost always impossible to get the phase integration right.

Huge posted:

Provided the integration of the sub to the main speakers is arranged correctly (crossover frequency, amplitude, cut rates and phase - N.B. true phase, not just 0°/180°) then use of a single sub is fine, since for bass frequencies you locate sounds by their harmonicas, not the fundamental.

To get the phase integration of a sub right usually means having a shorter distance to the listener for the sub than for the main speakers to compensate for the group delay of the sub's amplifier.  Using two subs located beside the main speaker is usually a far more compromised setup as then it's almost always impossible to get the phase integration right.

Thanks for that. Do you know of any links or articles that describe on the proper integration of a single subwoofer to the system with diagrams showing the recommended placement of the sub in the room?

 
Huge posted:

"Provided the integration of the sub to the main speakers is arranged correctly (crossover frequency, amplitude, cut rates and phase - N.B. true phase, not just 0°/180°) then use of a single sub is fine, since for bass frequencies you locate sounds by their harmonicas, not the fundamental."

I'm impressed, when did you learn to play the bass harmonica?

 

 

I've just read an article on Sound on Sound:-

"...crawl around on the floor listening at each potentially practical subwoofer location for which position gives the most consistent and natural bass sound."

Looks like it's not a straightforward job to place the subwoofer.

ChrisSU posted:
 
Huge posted:

"Provided the integration of the sub to the main speakers is arranged correctly (crossover frequency, amplitude, cut rates and phase - N.B. true phase, not just 0°/180°) then use of a single sub is fine, since for bass frequencies you locate sounds by their harmonicas, not the fundamental."

I'm impressed, when did you learn to play the bass harmonica?

Just now on the computer keyboard! 

ryder. posted:

I've just read an article on Sound on Sound:-

"...crawl around on the floor listening at each potentially practical subwoofer location for which position gives the most consistent and natural bass sound."

Looks like it's not a straightforward job to place the subwoofer.

Something that can give a good starting position (for subsequent optimisation) is to use the <Room Simulation> dialogue of "REW" to work out a few candidate positions to try.

ryder. posted:
Simon-in-Suffolk posted:

 The SCM 19 mk2 I have currently work quite well at low volume, although the bass extension semis to contract a little.

It is a bit worrying that you find the bass on the SCM 19 Mk2 to be deficient as I am looking at the SCM 11. May I ask, how big is your listening room and how far away are you sitting from the speakers?

Being small speakers the SCM19s don't have the greatest of bass extensions in the first place - meanwhile as sound levels reduce human hearing sensitivity drops off at the bass end more than middle frequencies, so with low level listening it is inevitable that the bass will sound lighter (unless the speaker rolls off so high as to not have much bass below about 100Hz at higher sound levels, therefore nothing to notice reducing in perceived level)

Huge posted:
ryder. posted:

I've just read an article on Sound on Sound:-

"...crawl around on the floor listening at each potentially practical subwoofer location for which position gives the most consistent and natural bass sound."

Looks like it's not a straightforward job to place the subwoofer.

Something that can give a good starting position (for subsequent optimisation) is to use the <Room Simulation> dialogue of "REW" to work out a few candidate positions to try.

I had a look at REW, but it seems it can only cope with simple rectangular rooms. Mine is full of alcoves, and I couldn't see how I could put any meaningful data into it.

ChrisSU posted:
Huge posted:
ryder. posted:

I've just read an article on Sound on Sound:-

"...crawl around on the floor listening at each potentially practical subwoofer location for which position gives the most consistent and natural bass sound."

Looks like it's not a straightforward job to place the subwoofer.

Something that can give a good starting position (for subsequent optimisation) is to use the <Room Simulation> dialogue of "REW" to work out a few candidate positions to try.

I had a look at REW, but it seems it can only cope with simple rectangular rooms. Mine is full of alcoves, and I couldn't see how I could put any meaningful data into it.

Hi Chris,

Unless the alcoves are particularly deep, then approximating a flat wall by using the mean distance between the walls will give a fairly good first approximation. True it doesn't cater for the edge diffraction or side reflections from the alcoves, but most people have furniture and it doesn't allow for that either!  After all, we're only after a 'first guess' at the position here.  The data below 200Hz are almost certain to be relatively unaffected by alcoves, as the wavelength is quite long (>1.7m).

Innocent Bystander posted:

Being small speakers the SCM19s don't have the greatest of bass extensions in the first place - meanwhile as sound levels reduce human hearing sensitivity drops off at the bass end more than middle frequencies, so with low level listening it is inevitable that the bass will sound lighter (unless the speaker rolls off so high as to not have much bass below about 100Hz at higher sound levels, therefore nothing to notice reducing in perceived level)

Thanks IB. That is certainly a valid point. I have read on the HifiPig review, I think, that the SCM11 or SCM19 needs to be played at 70dB and above to sound good and "complete". I am not sure if these speakers which have reduced bass output would sound acceptable at 50 to 60 dB as I sometimes listen at lower than average volumes. Having said that, both SCM11 and SCM19 got stellar reviews on Hifipig. The reviewers surely liked these speakers (not sure if there is anything that they don't like though).

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Drewy
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