I'm a little puzzled why you're conflating cabinet mass with imaging (whatever that is, since there isn't a specific definition)? Lack of stability or excess resonances may cause issues, but assuming x is 'key' is probably a bit of a stretch since different things come into play as they cause a variety of issues. 😉
They were very good speakers of their type for the time; one of the first to use laser interferometry and extensive computer modelling in the design. Miserable efficiency of course, like the cheaper SL6 they're based on, & limited outright dynamic range. As I recall, the midbass drivers had a PVC surround too, so they would actually change a little with room temperature -especially at colder levels.
They were very good speakers of their type for the time; one of the first to use laser interferometry and extensive computer modelling in the design. Miserable efficiency of course, like the cheaper SL6 they're based on, & limited outright dynamic range. As I recall, the midbass drivers had a PVC surround too, so they would actually change a little with room temperature -especially at colder levels.
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Hi because that was my experience I have a pair of speakers A crazy friend offered my to load the cabinets with lead slabs
I knew very well the sound of them before the experiment After the loading i listened to some pipe organ tracks but also jazz with bass and the sound was completely changed Before the pipe organ was weak and inside the speakers After the mod was very out of the speakers A lot of
Moreover the speakers sound as they are disconnected from the amp The sound is quite out of the cabinets
laser interferometry to check what ? that is another big curiosity of mine I hear often of this laser interferometry measurements What they measure specifically ?
That is not a problem at all Drivers can be changed quite easily with some similar size Scanspeak or similar Really not a problem
My guess is that the star here is not the driver clearly on the basis of what you say I am mostly insterested in soundstage I would say ONLY interested in soundstage Is what made me to fall in love with stereo listening
What we have here in the SL600 is a speaker very stiff but also very light If we can agree that it is a soundstage champion this rule out mass as an influencing parameter of soundstage reproduction I would like to understand if there is a key parameter for soundstage and which one is
I hate when people say ... everything counts Yes and there is no more middleseasons ... I need to set some stakes
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This will do nothing for rigidity, but certainly increase mass and potentially the physical stability of the individual panels, and load it more effectively to the floor. However, it will also likely have caused some other changes depending on exactly what 'slabs' were used, such as reducing internal volume & altering tuning as a result. These may or may not be significant, but I would be very wary about assuming or attributing a given result to a single cause without considering other factors.
Depends on what they're looking for, but as far as the SL6 / SL600 / SL700 & variations went, if memory serves it was primarily cone resonant profiles at varying frequencies; I think they did some for the panels too, but as noted, I'm going by memory & the file I have on them is in storage (like most of my things).
I didn't say it was for something else; I was talking purely about the SL600 (and its directly related models).
The drivers were actually very highly regarded for the era; early copper & latterly aluminium dome tweeters, a shed-load of work done on the midbass unit's cone, suspension & motor etc., and one of the earlier filters developed using computer modelling to help the development process. But a multiway is the sum of its parts and what you do with them -especially with the filter. A well-designed speaker using reasonably priced, decent-quality drive units can easily outperform a poorly designed speaker with extremely expensive, technically superior drive units. Or an equally well-designed one, that doesn't have characteristics that suit a particular set of requirements.
There is no specific / universal definition for soundstage that I know of -it's mostly (mostly) a term popularised by the hi-fi magazines from the '70s onward -especially those heavily or entirely reliant on subjective reviews. So without isolating specific features, you could end up chasing your tail with this. For whatever it's worth, I tend to agree with Zaph's comment:
'Some phrases are deceiving, such as soundstage width, depth, or height. What people are really hearing is a system's power response and it's [sic] interaction with the room.'
Assuming you have a relatively well behaved room & we're talking conventional direct radiators (and excluding line arrays), breaking this down a bit, I would generally say an even / consistent polar characteristic out to 45 degrees or so tends to lean in that direction, preferably with good phase-tracking through the transition band. A waveguide based system may suit if the room is more problematic or you prefer a slightly more focused dispersion character.
Except you suggest about that your lead-lined boxes (which will not be much stiffer than the originals, just heavier) improved in this regard, which seems to contradict your theory.
See above, but short version is that there isn't, because the term has no technical meaning in itself.
The problem is that everything does count to some extent, at least on generalised areas where numerous areas come into play, from the dispersion characteristics of the drive units (potentially their non-linear distortion as well), the quality of the filter design in marrying them together, the frequency & potentially the consistency of the polar response etc., the impedance load presented to the amplifier (a highly reactive load is rarely a good thing), the physical stability of the enclosure & whether it has any audible resonant issues, and then their positions in a given room. It's very tempting to try to focus on one thing and assume it is the one true physic 😉 (I suspect we've all been there), but unfortunately, most things are in practice a bit more complicated. Would that they weren't -life would be a lot easier.
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Yes of course lead is not a rigid material at all But to dampen vibrations i guess is one of the best around even if handling it is not the nicest job to do
They were lead foils thick about 2-3mm glued and screwed to the internal side of the cabinet panels So the reduction of the internal volume should be quite minimal And he took out all the mineral wool inside saying that was not needed anymore
I swear the effect on instruments with a lot of bass has been very evident At some point the speakers seemed completely disconnected from the amp
I saw a video from Wilson Audio describing a similar feeling with their speakers So my guess is that is a nice thing to get
But i understand also that dampening could absorb also energy through the driver frame Reducing its output ?
But ok I got the message I have to look more for stiffness and so it would be better to think of bracing a cabinet instead of loading it with mass
This is very important to me and also safer Lead is very toxic
Thank you very much Now i see better They used laser to check the diaphragms behaviour and not the cabinet vibrations I was confused because Laser Interpherometry is also used in vibrations analysis from what i have read I am reading now a review https://www.stereophile.com/standloudspeakers/744/index.html of the SL600si that confirms exactly what you say
Limiting the emission angle at least for dome drivers is a child game Felts are handy for that and indeed many designers have used them to limit the drivers H and V emission That it is easy to get Maybe some tests are needed to place them correctly around the drivers What is the reason to have a speaker that emits 180 degrees and then have to put on the walls all kind of accessories to block reflections ? why not deal with the out of axis emissions at speaker level ? what does not leave the speaker will not reach the walls I am fine with a great soundstage just in the listening spot
Lenses are more challenging for a DIY approach I do not see many lenses for dome tweeters for instance on the market
I like tweeter with little horns indeed
you say tempting I would say challenging I am not an expert but when we face a complex problem i think that one approach is to break it down in its components and analyze them separately ? for instance a stiffer cabinet would be a nice improvement with any drivers and crossoversThere isn't, because it has no technical meaning.
The problem is that everything does count to some extent, at least on generalised areas where numerous areas come into play, from the dispersion characteristics of the drive units (potentially their non-linear distortion as well), the quality of the filter design in marrying them together, the frequency & potentially the consistency of the polar response etc., the impedance load presented to the amplifier (a highly reactive load is rarely a good thing), the physical stability of the enclosure & whether it has any audible resonant issues, and then their positions in a given room.
It's very tempting to try to focus on one thing and assume it is the one true physic 😉 (I suspect we've all been there), but unfortunately, most things are in practice a bit more complicated. Would that they weren't -life would be a lot easier.
. This is where you need to nail down exactly what it is you are identifying as a characteristic. Once you've done that, it's usually easier to establish ways to achieve it (preferably on a repeatable basis).
A better driver who behave like a piston would be better with any cabinet and crossover And ... crossover i do not know which is the design better for soundstage honestly I read 1st order types ? dont know exactly
I wonder which is the stiffer wood I would think that all should be using it With additional internal bracing of course
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Well, assuming a good connection it lowers the overall panel Fs. Whether far enough to shunt it below the critical box operating region, or whether it simply stuffs it into that zone will depend on the box of course. I'd avoid lead like the plague though.
Oh dear. Yes, I bet it has. 😉
Not really (it would need to be very severe for the conversion efficiency to be significantly affected. But if there are vibrations in, or reintroduced into, its structure, that's not ideal. You want it stable & preferably isolated, as the pioneers did back in the day, rather than having it moving around which may affect the coil / suspension movement & increase linear / non-linear distortion.
Of the two that would certainly be my preferred option for bass enclosures (and especially avoiding lead) but it's not a panacea and the presence of mass with stiffness can sometimes be useful, so it's not a 'one is good, other is bad' situation.
They are, and this is frequently done. A 'child's game' however it is not, as the configuration, positioning & density have a significant impact on behaviour. Short version: they who do not measure do not know.
I've no idea. I haven't referred to a speaker with such a characteristic. I did mention through that a reasonably consistent polar response out to about 45 degrees tends to be beneficial in terms of stereo imaging, assuming a reasonably well-behaved room acoustic & good positioning, without significant issues with first reflections &c. A non-uniform power response amongst other things can affect the perception of tone, so consistency here is usually advantageous. This is not a synonym for 'flat response on & off axis' -just that it's usually better to avoid obvious flares or narrowings in the transition band from one unit to another -especially if they are abrupt.
Quoting my post above: 'A waveguide based system may suit if the room is more problematic or you prefer a slightly more focused dispersion character.'
That's news to me. Which is what I was trying (not very well) to explain. I doubt anybody would disagree that breaking down complex matters into component areas is good practice. But when doing so, it's very easy (tempting) to fixate on a single one of those (as you have just done there) and announce it to be some kind of panacea, when it actually isn't. A 'stiffer cabinet' would not, in fact, 'be a nice improvement with any drivers and crossover'. It might be for some, but definitely not all.
That (with no offense intended) is technical nonsense.
As I pointed out above, this will vary depending on the type of speaker & the situation it's intended for. The filter heavily influences (in some areas determines) the system frequency, power, polar, phase & impedance responses. In general, I would say that you want good phase tracking through the transition band, a relatively uniform polar / power response without obvious rapid flares, a sufficiently easy impedance load not to present the amplifier with excessive current-swings, and a frequency response trend that suits a given set of requirements. All of these can be manipulated to varying extents in the crossover, but there is no single type or design that will provide x characteristic in all situations.
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Hi thanks for the very kind and valuable support I was dreaming to solve my probems with just some lead slabs
Anyway i remember someone filling speakers with sand or even lead bullets For sure also sand is not stiff
I am not looking for SOTA performance ... just a little improvement for a boxy speaker (I have now lead in 4 pairs ... i am protected against radiations)
this i dont understand honestly If the dampening sucks out energy from the driver this should be measurable in some way And my best guess is that the speaker/driver sensitivity should decrease consequently This could be also tolerable if an high efficiency driver is used
Some dBs can be wasted if they are a lot
Anyway i was watching some TOTL subs on the Rel website and actually considering that they have also an amplifier on board are not that heavy
Much less than what i thought I guess they have very stiff cabinets as you recommend
No more doubts about stiffness the way to go I was reading about the old Celestion SL600 ... great soundstage from a speaker with a very light cabinet but also very stiff So mass is not needed
Ok but still not a big issue From the graph i am seeing many speakers intended also for professionals and very very expensive have like a sound channel very narrow above about 1kHz ... they "channel" the emission in a +/-30 degree I think that they are looking more for a constant/regular emission than a wide emission I like this approach a lot Like speakers shooting very precisely at me in the listening spot I usually do not dance when i listen to music or watch a concert
for sure my room is problematic Moreover i like the idea to save on acoustic treatment For instance to treat the ceiling is out of question
And side walls also because i have paintings Front and rear walls instead can be treated without big issues So yes i guess that for me a waveguide system is the way to go Or using felts on a conventional speaker ... i was watching the AR93 using them already in the 1985 (and also two lower woofers back to back )
this i cannot understand really A better cabinet should improve the performance of any driver anytime
And i am sure that there are indeed better designed and built cabinets Just i do not know which they are I would like to see a masterpiece of cabinet
Anyway from what you told me i think that the Matrix cabinet of the 801 should be an example of very very good cabinet
fwiu the stiffness comes from extensive internal bracing ? And they are made out of MDF if not chipboard Not a very exotic material indeed
I had in the past a pair of B&W Matrix 1 that i destroyed to see inside From what i remember i did not like the sound of the woofer ... sluggish
But now i have cleared up my mind a lot
If i had to mod a speaker cabinet i would place just a very thick brace above the woofer and stop like in this speaker here
https://i.pinimg.com/originals/8f/06/59/8f06590f26c575d193ae2afeeff7c0af.jpg
Thanks again and good to know. I focus on the cabinets because crossover design is much more complex and completely out of my reach
When i see filters with dozens of parts i am shocked But as always there are measurements to show that complexity often pays dividend in terms of sound quality
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Stiffness doesn't prevent absorption, it is part of the resonance. You might look to push the resonance higher in frequency.
Mass makes the panels take more to move, but it also takes more to stop them.
Are we talking about high volume when we talk about the material in the box?
I don't think my boxes I made in mdf move a bit when I play music.
I don't think my boxes I made in mdf move a bit when I play music.
You could always go FR speaker on an OB. Set both the cabinet factor and crossover factor to "none". Even then, it's not easy-peasy; take away the cabinet housing structure, what's the speaker pushing against then? A flappy-board... Complexity of mechanical physics coming back at you as you try to solve those problems.
The listening level won't come into play... more cone movement, more push against the cabinet. It's all proportional.
In any case the cone is much lighter than the box by some orders of magnitude, and the box itself isn't free floating.
Hi thanks again Let me see if i have understood correctly If i use a very stiff cabinet connected to the woofer the resonance is moved to high Hz and so easier to dampen with simple sheets of dampening material ? this is very interesting But to get stiffness from wood i guess that high thickness or layered panels are needed With the best option being metal panels that will be much stiffer than any wood ?
The only experience i have with FR is a Redheko speaker that i liked but i found lacking in the very bass and the very high An exciting speaker for sure But also FR i am afraid not
I dont like OB I cannot explain why But in general i dont like speakers that emits also towards the rear wall I much prefer direct firing speakers
That's OK; there were times in my life I wouldnt have liked it either. My post was mostly to illustrate how far to the fringes one can go, if crossovers and cabinets are overly perplexing. And to say there's still problems with that!
I've done some - very little - playing with cabinet materials. A couple findings perhaps relevant to your pursuit;
1. A differing material layup - the only one I've done is wood-cork-wood - beats straight wood. The more layers in the layup, the better, even with straight wood, which is commonly known.
2. The cabinet is going to emit something and the material it's made from makes a difference in the sound quality of that emission, whatever it is. In acoustic guitar building, they have this concept of "tone wood", which simply means some woods are better than others regarding the instruments sound quality.
3. I'm pretty sure I've observed a "hashy" sound coming through a commercial speaker cabinet built using MDF, which suggests non-linearity in its transmission characteristics. I'll walk out on the plank here and suggest better wood - er, material - doesnt do that so much and the best wood doesnt do it at all.
4. Philosophy; you can move heaven and earth to try and completely quell (think steel reinforced concrete) any cabinet movement in response to SPL and vibration input from speaker drivers - or you can drop the fight, work with it instead to somehow craft a good sounding speaker cabinet. In guitar building land, they say a good sounding acoustic guitar sounds like a piano - all notes about equal. I have no idea how they do it, however some people do have that knowledge, as they can craft and sell instruments in the $10k and up range.
I'm pretty sure no one pays that much for a clinky, boxy sounding guitar. It better sound like it was made in Heaven. Could a similar characteristic be attained in the cabinet for a speaker, if the goal of "inert" is dropped for "if the cabinet is going to emit something, it might as well be pleasant"?
Hi thanks a lot for your valuable advice Actually i have seen many "layered" cabinets ... both vertically and horizontally where thin layers of maybe different woods are glued and pressed together Or even thicker layer That for sure makes construction much more challenging
I was even thinking to use inserts and bolts to join different panels to simplify things But almost no one uses this technique
i dont understand completely when speaking of speakers we start to talk about musical instruments The requirements of an acoustic instruments in my mind are completely opposite of the requirements for a speaker The "cabinet" of an instrument makes the sound The cabinet of a speaker should have no sound by itself The driver makes the sound not the cabinet To see a speaker as an instrument is completely wrong The cabinet should not add anything to the sound If so it will colour it unnaturally Like adding distortion
one thing for sure i have observed ... boxiness The sensation that the speaker is not letting the sound coming out from the box And it is really bad indeed There are some points that are really obscure to me Like when they say that a overdamped cabinet will suck out energy from the drivers
Then i said that this should reflect in a decrease in sensitivity And they told me no This is not possible If after heavy dampening of the speaker the sensitivity remains the same it means that no energy is really wasted It could be that indeed the sensitivity will go down This i dont know
I did not measure it on my overdamped speakers
I am sorry to repeat myself but i am using a very simple test to check for the tendency of a speaker cabinet to resonate
I am using one of this mechanism
https://m.media-amazon.com/images/I/71jBdMQozUL._AC_SL1500_.jpg
it is an extremely telling test that was suggested to me at an audio fair You put it on the cabinet of which you want to check the tendency to resonate and rotate the mechanism The louder the sound the more resonant the cabinet
Of course it is qualitative but very telling I can say that the unloaded cabinet sounded much louder than the dampened cabinet
However i have never tried a stiff and light cabinet My speakers are all made of cheap chipboard
thank you for the very interesting information but again i think that going on comparing two completely different applications can be misleading
The test with the carillon is very very telling It can be also used to check the resonant character of single panels alone Even if i am afraid a cabinet being a box will resonate much more than one of its panels
And one costs about 4 euro I have the jingle bells one
I would love to use it on a speaker like the Celestion SL600 Its cabinet is completely opposite than mine Very stiff and not dampened The Celestion
When i saw their weight of only 11.25 lbs i was shocked And they say that they are soundstage champions My ultimate dream
Attachments
The "philosophy" I presented is based on the idea that a speaker cabinet will make radiant sound when excited by the drivers. Unless you "move Heaven and Earth" to stop it from doing so completely. It's the nature of human sound perception to pick up on the small, which is why it takes a lot of effort to get those emissions below what anyone may still hear.
So a cabinet will make it's own sound from speaker excitation, you almost cant get rid of it completely no matter what - so why not "judo" the situation and make whatever the sound the cabinet will do a pleasant one, as long as you're - possibly - going to hear something from it?
I fully understand the idea that a speaker's enclosure isnt a musical instrument. Yet, if it's gonna emit something, it should be a pleasant sound, versus a nasty one as I think I experienced through that MDF cabinet. I think it's achievable, such that cabinet A simply sounds OK, "sweeter", more "alive" than B with the same drivers / xover, as subtle as the difference may be. And you know what folks will pay for those subtle differences in all things that make sound.
I think i understand the idea First there is reality and ideality The best result is the one the approach ideality more We tend to ideal behaviour as the ultimate goal
The more radiant sound a cabinet makes the more its behaviour deviates from ideality Because a speaker must not make/amplify the sound It must reproduce it The drivers makes the sound
I know that some manufacturers try to "marry" the cabinet sound together with the drivers sound This is a wrong approach imho
If their speakers sound good anyway i am sure that the same drivers and xover would sound even better in a less resonant cabinet Because the less resonant cabinet would be more ideal
I would say good luck with that I see the task extremely challenging indeed I think that to design and make a non resonant cabinet is much less challenging then what you are willing to do Some lead strategically placed would cancel almost any resonance It is the most acoustically dead material i know
You hit a lead slab with a hammer and hear almost nothing Just a tud
The only doubt i still have is about the final sensitivity of the speaker If the dampening indeed decreases the overall efficiency of the speaker that is a real problem Because the speakers/drivers should be the more efficient possible No energy should be wasted
We have a speaker manufacturer here in Sweden that fills the speakers with foam rubber.
He orders speaker drivers with special small parameters to adapt them in the boxes.
He is a trained sound professor and he knows everything about how the ear experiences different frequencies.
We are extra sensitive to frequencies between 2000hz - 4000hz to, for example. He creates speakers that are adapted accordingly.
The boxes are quite common but time-optimized between bass/mid range and treble. The treble is placed further back than the bass/mid range.
He orders speaker drivers with special small parameters to adapt them in the boxes.
He is a trained sound professor and he knows everything about how the ear experiences different frequencies.
We are extra sensitive to frequencies between 2000hz - 4000hz to, for example. He creates speakers that are adapted accordingly.
The boxes are quite common but time-optimized between bass/mid range and treble. The treble is placed further back than the bass/mid range.
i still have not understood if all the sides of a cabinet are equally important for resonances I thought naively that front baffle was the more critical
But in all the measurements i have seen (i.e. mostly in Stereophile magazine) they place accelerometers practically everywhere but the front baffle
Never Then i see brands like Avalon that has used even 4.5" thick baffles and other side around 1" And i get even more confused
But in all the measurements i have seen (i.e. mostly in Stereophile magazine) they place accelerometers practically everywhere but the front baffle
Never Then i see brands like Avalon that has used even 4.5" thick baffles and other side around 1" And i get even more confused
If it is mainly the low frequencies that affect most of the vibrations from the box, then they are difficult to locate. If they come from side panels that are probably less stiff than the front, they might measure from those.
Maybe the sides of the box disturb the sound more than you think.
Maybe the sides of the box disturb the sound more than you think.
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