Improving loudspeaker crossovers (SBL's)
 

I find myself amazed that we're collectively prepared to spend thousands
on
new amplifiers, CD players etc, let alone silly money on cables or mains
conditioners, when we're not willing to put in some basic acoustic
treatment.

----------------

As important IMO as the equipment. I've had to make the best of a bad
situation, lashing out on wall papering all the walls, large carpet mat on
top of a floored carpet & some soft furnishings (not to mention myself!) in
the likes of cuddly animals & comfy chairs, the listening one being the most
comfy :-) In addition I've kept the speakers away from the corners &
slightly out into the room. Currently experimenting with marble base plates
(bread boards) to rest the speakers on.

Improving loudspeaker crossovers (SBL's)
 

"Rob" wrote in message
...
Serge Auckland wrote:
"Rob" wrote in message
...
Serge Auckland wrote:
"Stevie Boy" wrote in message
...
snip leaving rigid definition part

Neutrality: Where a sound is reproduced as accurately as possible
without emphasis of any frequency.
In other words as life like as possible.
The two statements are not synonymous. Lack of emphasis of any
frequency means a flat frequency response, with no sharp peaks or
troughs, especially peaks. "As life like as possible" implies not only
a flat response, but also low distortion and accurate dispersion
characteristics which, when the room acoustics are included, result in
an accurate representation of the recorded event. The closest approach
to the original sound anyone?

If the OP had added that accurate meant 'original', and that emphasis
meant change, would that have cheered you up?

And 'an accurate rendition' of an 'original' need not represent
'lifelike'. If someone thinks an oboe sounds more like an oboe with
certain things added or taken away from the original recorded sound (as
opposed to the performance), is that not more lifelike, and hence
neutral?


Bass weight: A stronger representation of the lows as if it were a
larger speaker.
How does this differ from extention?

Perhaps it does mean extension, although not necessarily linearly.

Imaging: placing voices & instruments at a point in space.

Soundstaging: How a performance fills the room, does the sound feel it
is in the room (if so does it fill the whole room or sound as if it is
confined to within the speaker listening positions), confined towards
the speakers or eminating from the speakers!
This is primarily a function of the room, together with the dispersion
characteristics of the loudspeakers.

Room a big factor no doubt, but often not practical to remedy. I do find
that valve amplification and a vinyl source create (recreate?!) a sense
of space, making sound more like music. Just thought I'd mention it ;-)

Rob

Now that electronics have reached the present level of perfection, the
room is the single biggest factor affecting accurate sound reproduction.

I find myself amazed that we're collectively prepared to spend thousands
on new amplifiers, CD players etc, let alone silly money on cables or
mains conditioners, when we're not willing to put in some basic acoustic
treatment. Maybe it's the low WAF, or maybe we're not artistic enough to
make the stuff look acceptable, or maybe it's a bit more difficult to
brag down at the pub that I've just bought a new bass trap.

Whatever the reason, we throw money at equipment without tackling first
what the equipment is going to work into, i.e. the room. I have visited
several friends with what would otherwise be very good systems, to find
that the sound is dire due to poor loudspeaker positioning (e.g. QUAD
ELS63s in corners) poor acoustics (bare tiled floor, minimalist decor),
large 'speakers in tiny rooms for hi-fi when the TV is in the large
room, stereo 'speakers at different heights on top of furniture, and
don't get me started on people's surround-sound efforts. Get the room
right *first* using a modest system, then upgrade.


Well, I'm not amazed. The little I've read on the subject seems to
indicate a need to make and understand measurement, extensive listening
with a range of music (and films etc), and converting living space into
some sort of sound box. The act/art of compromise is also tricky. Do you
have a favoured book/web resource you could point me to?

I've just plonked some Castle Harlech* speakers in my front room - they
shouldn't work, but on a lot of music they sound splendid.

Rant over! Merry Christmas
S.

Pick it up in the new year! Merry xmas to you and all.

Rob

* at my local dealer, £300, leaving me nowhere to go :-)


Nice buy at £300! Hope you get them working well in the room.

As to acoustics, a lot of what I know has just come for 35 years experience
of designing and working in Broadcast studios, albeit as a broadcast
engineer, never as an acoustician. Have a look at my web site and you can
see what I've done to my own listening room. There are also links to a very
useful forum and to some DIY acoustic absorbers. Finally, have a look at
www.acoustics101.com It's aimed at small recording studios, but the
principles are identical to a domestic setting, you just need to pay a bit
more attention to cosmetics, or have a very understanding partner. Either
way, the acoustic treatment I did cost only a few hundred pounds excluding
the rug, the most expensive thing was the curtains to hide it all behind.

Have fun,

S.


--
http://audiopages.googlepages.com

Improving loudspeaker crossovers (SBL's)
 

"Stevie Boy" wrote in message
...

I find myself amazed that we're collectively prepared to spend thousands
on
new amplifiers, CD players etc, let alone silly money on cables or mains
conditioners, when we're not willing to put in some basic acoustic
treatment.

----------------

As important IMO as the equipment. I've had to make the best of a bad
situation, lashing out on wall papering all the walls, large carpet mat on
top of a floored carpet & some soft furnishings (not to mention myself!)
in the likes of cuddly animals & comfy chairs, the listening one being the
most comfy :-) In addition I've kept the speakers away from the corners &
slightly out into the room. Currently experimenting with marble base
plates (bread boards) to rest the speakers on.
Wallpaper will make a very small difference, unless it's 100mm thick! What
you're trying to achieve is a short reverberation time which means plenty of
soft furnishings, carpeted floor and so on. In "normal" sized listening
rooms you're also trying to suppress early reflections from side walls,
which requires some wide range absorption on the sides. Early reflections,
especially if there is some frequency dependant absorption, will confuse the
stereo image, and change the perceived frequency response. This is most
easily achieved by 75-100mm of rockwool positioned from ground level up to,
say, 150cm high up the walls. These can be in the form of free-standing
panels (gobos) or attached to the walls.

You also may need to suppress the echo from the ceiling , but provided the
room is reasonably symmetrical, this will affect both channels equally and
won't have too serious an effect on the stereo image. It *will* affect bass
resonance by allowing standing waves, but if the floor is very absorbent
(e.g. thick carpet and underlay), then resonances will be reduced somewhat.

Corners will cause a bass boom, so if you can, position some corner
absorbers, or move the 'speakers about to minimise the effect. You will
probably end up with conflicting requirements for 'speaker positioning, one
position gives good imaging but the bass booms, another minimises bass
problems, but early reflections affect the image and so on. Ultimately, some
rooms just aren't any good for stereo. However, if you are willing to
experiment, most rooms can be made usable.

My web site shows what I've done to my own listening room, there are also a
couple of useful links to acoustics web sites. Also, have a look at
www.acoustics101.com for more advanced ideas. It's aimed at the small
recording studio, but is equally valid domestically, albeit with more
attention to the cosmetics.

What do you think will be achieved by standing the 'speakers on breadboards?
If you have suspended wooden floors I would isolate the 'speakers by
mounting them on rubber. Alternatively, you could use mass, but you'll need
an awful lot more than a marble slab ( a couple of tombstones might work!
I'd like to hear the discussions with one's wife over than suggestion....)

Anyway, good luck.

S


--
http://audiopages.googlepages.com

Improving loudspeaker crossovers (SBL's)
 

"Stevie Boy" wrote in message
...

* Laminated iron core inductors are much better than ferrite core
inductors.

Actually it turns out they are ferrite cores.

**If you replace them, ensure the resistance of the replacement coil is
identical. I am not well pleased with ferrite core inductors.


* Solder all connections.

It's built on a copper track PCB.

**ALL Connections. That includes connections to the drivers.


* Cover all internal surfaces with a suitable damping material. I rather
like Bostik Sound Deadening panels.

Are you talking about the cabinets themselves?

**Of course.

The crossovers are externally
mounted.

**Your point being?

Trevor Wilson

Improving loudspeaker crossovers (SBL's)
 

On Sat, 22 Dec 2007 18:45:44 -0000, "Serge Auckland"
wrote:

As important IMO as the equipment. I've had to make the best of a bad
situation, lashing out on wall papering all the walls, large carpet mat on
top of a floored carpet & some soft furnishings (not to mention myself!)
in the likes of cuddly animals & comfy chairs, the listening one being the
most comfy :-) In addition I've kept the speakers away from the corners &
slightly out into the room. Currently experimenting with marble base
plates (bread boards) to rest the speakers on.

Wallpaper will make a very small difference, unless it's 100mm thick!

But it may be audiophile wallpaper from Russ Andrews :-)

Improving loudspeaker crossovers (SBL's)
 

Laurence Payne wrote:
On Sat, 22 Dec 2007 16:25:08 +0000, Rob
wrote:

I've just plonked some Castle Harlech* speakers in my front room - they
shouldn't work, but on a lot of music they sound splendid.

What DON'T they sound splendid on? Can you analyse why?

Any pop/rock that sounds edgy/sibilant at the mid/top end - the Castles
seem to exaggerate it. Classical sounds superb, on the other hand, even
relatively shrill strings. It's difficult for me to tell whether they're
simply showing up bad recordings or source, or they're 'tuned' that way.
Also, when loud, the sound is simply uncomfortable and exaggerates this
effect. I wouldn't say distorted, more 'shouty'. They've taken the place
of some Dynaudio Contour 1.1s, which never had these traits - so I'd
conclude the Castles have a tendency towards edgy treble. The bass,
while a little uneven at times ('inaccurate'), is plentiful and enjoyable.

Keith would never thank me for this (!), but the overall tone reminds me
of some of his horn speakers.

Difficult to tell whether they're here to stay. I've found some music
sounds astounding, good as I've heard - well recorded pop (Pink Floyd,
say) and classical, but if I find myself not listening to music because
of their foibles, they may have to move along ...

Having said this, I'll have a look into Serge's ssuggestions on rooms.

Rob

Improving loudspeaker crossovers (SBL's)
 

Serge Auckland wrote:
"Rob" wrote in message
...
Serge Auckland wrote:
"Rob" wrote in message
...
Serge Auckland wrote:
"Stevie Boy" wrote in message
...
snip leaving rigid definition part

Neutrality: Where a sound is reproduced as accurately as possible
without emphasis of any frequency.
In other words as life like as possible.
The two statements are not synonymous. Lack of emphasis of any
frequency means a flat frequency response, with no sharp peaks or
troughs, especially peaks. "As life like as possible" implies not only
a flat response, but also low distortion and accurate dispersion
characteristics which, when the room acoustics are included, result in
an accurate representation of the recorded event. The closest approach
to the original sound anyone?

If the OP had added that accurate meant 'original', and that emphasis
meant change, would that have cheered you up?

And 'an accurate rendition' of an 'original' need not represent
'lifelike'. If someone thinks an oboe sounds more like an oboe with
certain things added or taken away from the original recorded sound (as
opposed to the performance), is that not more lifelike, and hence
neutral?


Bass weight: A stronger representation of the lows as if it were a
larger speaker.
How does this differ from extention?

Perhaps it does mean extension, although not necessarily linearly.

Imaging: placing voices & instruments at a point in space.

Soundstaging: How a performance fills the room, does the sound feel it
is in the room (if so does it fill the whole room or sound as if it is
confined to within the speaker listening positions), confined towards
the speakers or eminating from the speakers!
This is primarily a function of the room, together with the dispersion
characteristics of the loudspeakers.

Room a big factor no doubt, but often not practical to remedy. I do find
that valve amplification and a vinyl source create (recreate?!) a sense
of space, making sound more like music. Just thought I'd mention it ;-)

Rob

Now that electronics have reached the present level of perfection, the
room is the single biggest factor affecting accurate sound reproduction.

I find myself amazed that we're collectively prepared to spend thousands
on new amplifiers, CD players etc, let alone silly money on cables or
mains conditioners, when we're not willing to put in some basic acoustic
treatment. Maybe it's the low WAF, or maybe we're not artistic enough to
make the stuff look acceptable, or maybe it's a bit more difficult to
brag down at the pub that I've just bought a new bass trap.

Whatever the reason, we throw money at equipment without tackling first
what the equipment is going to work into, i.e. the room. I have visited
several friends with what would otherwise be very good systems, to find
that the sound is dire due to poor loudspeaker positioning (e.g. QUAD
ELS63s in corners) poor acoustics (bare tiled floor, minimalist decor),
large 'speakers in tiny rooms for hi-fi when the TV is in the large
room, stereo 'speakers at different heights on top of furniture, and
don't get me started on people's surround-sound efforts. Get the room
right *first* using a modest system, then upgrade.

Well, I'm not amazed. The little I've read on the subject seems to
indicate a need to make and understand measurement, extensive listening
with a range of music (and films etc), and converting living space into
some sort of sound box. The act/art of compromise is also tricky. Do you
have a favoured book/web resource you could point me to?

I've just plonked some Castle Harlech* speakers in my front room - they
shouldn't work, but on a lot of music they sound splendid.

Rant over! Merry Christmas
S.
Pick it up in the new year! Merry xmas to you and all.

Rob

* at my local dealer, £300, leaving me nowhere to go :-)


Nice buy at £300! Hope you get them working well in the room.

As to acoustics, a lot of what I know has just come for 35 years experience
of designing and working in Broadcast studios, albeit as a broadcast
engineer, never as an acoustician. Have a look at my web site and you can
see what I've done to my own listening room. There are also links to a very
useful forum and to some DIY acoustic absorbers. Finally, have a look at
www.acoustics101.com It's aimed at small recording studios, but the
principles are identical to a domestic setting, you just need to pay a bit
more attention to cosmetics, or have a very understanding partner. Either
way, the acoustic treatment I did cost only a few hundred pounds excluding
the rug, the most expensive thing was the curtains to hide it all behind.

Have fun,

S.


Many thanks for that, I'll have a look. I think an enduring point is
your experience - you could look at a room and diagnose/treat with some
accuracy fairly quickly. It'd take me a fair while, and I'm not very
good at evaluating sound under test conditions. But it does look this
side of fun, if not quite new year resolution material :-)

Rob

Improving loudspeaker crossovers (SBL's)
 

Serge Auckland wrote:

What you're trying to achieve is a short reverberation time which means plenty
of
soft furnishings, carpeted floor and so on.

Well it's a combination of reducing the reverberant field's *intensity* as well
as the reverberation time.

You don't want to 'overdamp' a room though, it won't sound natural. The ear
adaps naturally to dealing with a modest reverberant field.

Graham

Improving loudspeaker crossovers (SBL's)
 

**ALL Connections. That includes connections to the drivers.


Easier said than done as the driver cabinets are extremely difficult to get
into as the drive units use a sealant to ensure a air tight fit.

* Cover all internal surfaces with a suitable damping material. I rather
like Bostik Sound Deadening panels.

Hmm I'm not saying this is a bad idea as I've used sound deading panels &
materials in car door panels before with great effect (car doors arn't
exactly rigid affairs) but the SBL's use some rather unique tuning devices
(not sure what they are made of) that are adhered to the inside of the
enclosures. I know this as I saw an internal unit at thier launch. It's also
a one of treatment, like it or hate it once it's done.

The crossovers are externally
mounted.

**Your point being?

My point was to merely mention where they were as I was not sure in your
post what you were refering to in damping.

Improving loudspeaker crossovers (SBL's)
 

"Eeyore" wrote in message
...


Serge Auckland wrote:

What you're trying to achieve is a short reverberation time which means
plenty
of
soft furnishings, carpeted floor and so on.

Well it's a combination of reducing the reverberant field's *intensity* as
well
as the reverberation time.

You don't want to 'overdamp' a room though, it won't sound natural. The
ear
adaps naturally to dealing with a modest reverberant field.

Graham

Indeed. Too short a RT and the room sounds dead. However, in my view what
you don't absorb should be diffused, so I mix a certain amount of absorbtion
with diffusion. In a domestic setting, a bookcase with different size books,
and with several gaps which could have small ornaments (standing on felt so
they don't rattle) makes an acceptable diffuser. A slatted ceiling can be
very effective as both a diffuser and absorber, and look attractive if well
done.

S.


--
http://audiopages.googlepages.com