Casters vs Spikes

[NickofWimbledon]

FWIW I am shitposting to some degree as the audiophile groupthink regarding spikes is just so absolute, all encompassing and exists in almost total isolation to pro-audio (where isolation is favoured/coupling avoided) that I just find it amusing. I’m sure the point of “we need to put spikes on this because people expect spikes on this” was reached decades ago and as such it is now just marketing/groupthink rather than based in any logic or credible research. I also feel the whole marketing thing this is connected to has conditioned people in dem rooms to select the leaner and more attacking of two choices and over the 40+ years that this mindset has existed audio has moved far too far from a genuinely natural balance and presentation. I’m of the mindset that if a hi-fi system sounds very different from say a well setup pair of Quad 57s, BBC monitors, HD-600s or whatever then it is quite simply wrong.

That said spikes do clearly have some use with narrow top-heavy speakers e.g. slim floor-standers, mini-monitors etc when used on carpeted floors as they are inherently unstable structures. A wide spiked base makes them vastly more stable and can be achieved without nailing them to the floor and transmitting every vibration directly into the room structure (which to my thinking is a very bad thing). The more I think about the ‘problem’ the more I suspect the ideal mini-monitor stand would be a lightweight low-resonance wide-footprint tripod without any spiking top or bottom, i.e. felt pads at the top, rubber feet at the bottom. The footprint would give stability without rocking, a light material (wood, carbon, fibreglass or whatever) would avoid all the negatives of mass-loading (energy storage, sucking dynamics etc). The nearest I’ve seen to what I have in mind are the Audio Chic wood stands and I’d love to try a pair under the JR149s & LS3/5As, but they are far too expensive to just take a random punt on.

That looks very fair - it's one of the least challenged bits of 'conventional wisdom'.

From trying things out, I have concluded that coupling a massive concrete floor to a speaker usually works very nicely - if the speaker is able to energise (say) 5 tons of concrete in any meaningful way, you are playing too loud. Spikes on a sprung wooden floor may still help ensure the speaker doesn't rock, wobble or fall over, but closely coupling speakers to soundbox-flooring is not the perfect idea.

It is interesting that, without making a fuss about it, increasing numbers of makers offer spikes in the box but actually demonstrate their speakers on Gaias.

 

[Purité Audio]

Just worth remembering that there has to be enough structural borne vibration to create an AUDIBLE resonance from the floor.
Keith

 

[James]

One of the more extreme measures I have seen to deal with a suspended floor was to extend a pair of pillars to the ground below. The loudspeakers were perched atop the pillars. This required two holes to be cut in the floor. The land lord was not pleased.

 

[Mullardman]

They will almost certainly make things sound worse IME. Mass is generally bad, adding even more moves things in the wrong direction to my ears.

That's a rather sweeping statement Tony....in the face of innumerable possible scenarios...which is why I said upthread that I don't believe in 'one size fits all' solutions.
That includes spikes. They work with my speakers, getting through carpet etc., down to a solid floor and mostly, allowing for a solid stable set up. I can't comment on spring supports, having not tried them.

In the context of a suspended wooden floor, perhaps. Not in the case of coupling a smaller vibrating thing to a something magnitudes more massive like a concrete pad.. But each to their own, and by their own experiences.

Just what I have. The spikes get through the carpet and allow me to get the speakers vertical. That's just a simple practical consideration and not really an 'audiophile' thing.

However, regarding sound, two things worth pointing out.
Way back, courtesy of Hi Fi World, I had a nice pair of the original Tannoy 603s .with the nice 'tortoiseshell' inlay and the dedicated stands. As I recall there was provision for the speakers to be bolted to the stands. Some chap wrote to hi fi world saying that he'd loosened the bolts on his and got 'much better bass'. It tried and and, unsurprisingly to me, got flabby, slow bass, like a cheap AV sub droning on for days after the note is struck. That says something to me about holding speakers steady.
I know Tony disagrees with me on this, but I firmly believe that as a bass cone moves, and moves air, it will suffer 'lost motion', if the cabinet which it is fixed into is able to also move, which I'd expect as a result of Newton's Third Law.
There is no doubt in my mind that my speakers, being effectively a floorstander, sounded way better after I replaced the lightweight Rogers MDF plinth with a granite base of wider profile and higher mass, which prevents rocking.

There is also the argument, which I can neither confirm nor deny, that movement of a small speaker induced by the antics of a bass cone, can interfere with the hf units/ tweeters, upsetting imaging.

All I know is that on decently recorded material, my speakers sound damned good the way I have them set up.
Nothing can save crap recordings.

 

[Mullardman]

Just worth remembering that there has to be enough structural borne vibration to create an AUDIBLE resonance from the floor.
Keith

Maybe. I'm not sure. But maybe at least allow the possibility that any resonance in the floor could 'beat' with the sounds from the speaker, to detrimental effect..

 

[James]

Some chap wrote to hi fi world saying that he'd loosened the bolts on his and got 'much better bass'. It tried and and, unsurprisingly to me, got flabby, slow bass, like a cheap AV sub droning on for days after the note is struck. That says something to me about holding speakers steady.

It says something about what 'better bass' means to some people.

 

[Tony L]

I know Tony disagrees with me on this, but I firmly believe that as a bass cone moves, and moves air, it will suffer 'lost motion', if the cabinet which it is fixed into is able to also move, which I'd expect as a result of Newton's Third Law.
There is no doubt in my mind that my speakers, being effectively a floorstander, sounded way better after I replaced the lightweight Rogers MDF plinth with a granite base of wider profile and higher mass, which prevents rocking.

There is also the argument, which I can neither confirm nor deny, that movement of a small speaker induced by the antics of a bass cone, can interfere with the hf units/ tweeters, upsetting imaging.

I certainly don’t disagree with Newton’s Third Law, I just think many audiophiles tend to start from a total misunderstanding of it!

It is clear a loudspeaker is a vibrating device. The driver, cabinet mass, and the vibrational frequency also need to be clearly understood. This is where most people fall down. In your case you have a 5” bass-mid driver trying to move a 5kg cabinet at a complex broadband frequency from around 50Hz through to 20kHz. This input is effectively self-cancelling AC once you factor cabinet mass and audio frequency. Yes it brings some supplemental sympathetic vibration into the cabinet structure itself, but not at a frequency that can possibly be stabilised by a “rigid” stand (an item which actually doesn’t exist on this planet). It is far better IMHO to pick a loudspeaker where the cabinet resonance has been carefully analysed and engineered to be at a certain level and ‘Q’ so it is non-destructive musically and also doesn’t store too much energy. This is why personally if I want a box speaker it is likely going to be a BBC designed one as they really thought this stuff through rather than just fling mass at the problem (which is a disaster to my ears as it just sucks dynamics and life). I really do not like the sound of heavy loudspeakers, especially ones made from MDF, which stores energy like a capacitor. Give me a light damped cab with a calculated and controlled resonance behaviour every time. The mass of the cabinet is still vastly greater than the driver energy at the frequencies concerned, so it isn’t going anywhere in the grand scheme of things.

The key mistake audiophiles and dealers make is to associate “rigidity” with what it feels like to push something with their finger, i.e. does a stand feel “fixed in space”. This is a real idiot-grade misunderstanding of the forces in place at the frequencies they are occurring at. It really does not matter if something “feels rigid” unless you are measuring that movement and energy release right up in the audio band, i.e. unless you are capable of moving a stand at 30Hz, 1kHz, 10kHz or whatever that perception really is irrelevant! In reality you’ll likely find a “rigid” stand is actually adding resonance in the audio band by ringing etc. I’m certain this is the case with some lightweight resonant stands e.g. Kan stands. Some folk like this, and when designed-in as part of a system it is a legitimate approach (I do like Kans!). Just don’t think of them as being rigid as they clearly aren’t. No stand is.

As you know I am not a fan of the Rogers AB1s and would consider them about the worst place imaginable to put a nice pair of mini-monitors. As such you are to my mind starting from a very odd and compromised place; a narrow-footprint hollow MDF box with an audio-frequency vibration device inside! Maybe the added floor mass may help here, I’ve no idea. It’s out of my ballpark as I’d personally far, far prefer the Studio 3s, which I’m sure I’d like a lot, without subs on a nice pair of stands. In that scenario I’m pretty certain the granite would move things backwards sonically to my ears. I’d actually put money on it.

 

[Mullardman]

I'm not going to insist that you are incorrect about the possibility of a cabinet moving backwards, as a cone pushes forward. I see your point about 'self cancellation' and of course I'm also aware of inertia, but I'd surmise that the forward motion of a cone working against ambient pressure in the room is different to the cone moving back to 'rest'. Of course ambient pressure plus the lowered pressure in the ( sealed) box caused by forward motion will 'encourage' the cone back. But forward and back motion are not necessarily equal. Surely the cone behaves aerodynamically differently going forward and backwards simply because it is a cone, not a flat surface?
Eitherway I doubt that issue can be resolved for sure without suitable testing with accelerometers or whatever, so I'm happy to continue with my setup.
I can't discuss Kans other than to say that I've never heard a pair I liked, however driven and on whatever stands. I had an early pair briefly and could never get them to do much other than shreik, using several different and highly competent amps. I'm not sure allowing for a resonance in lightweight Kan stands, just because you like the effect really helps your case.
AB1. You are of course entitled to dislike them. I'm guessing you've heard them with LS3/5As. I haven't. Eitherway, whatever the charms and the extensive following of the LS3/5A, it was only ever designed as a grade 2 near field broadcast monitor and has its limitations in both power handling/ max SPL and bass extension.
So. The Studio 3. Just as a reminder it was designed by Andy Whittle at Rogers, as a (presumably commercially imperative) replacement for the LS3/5A, after KEF had a fire and the supply of drive units, specifically T27 tweeter and B110 mid bass drivers, was interrupted, with the potential to close off production of Rogers' flagship product.
The Studio 3 uses the same size cabinet as the LS3/5A, made from the same birch ply and beech fillets, with critically damped panels and internal foam damping. The drive units and crossover differ from the BBC design and the result is a speaker with a quoted frequency response of 80Hz-21kHz +/-2dB, as opposed to LS3/5A 80Hz-20kHz +/-3dB.
Overall an arguably more domestically friendly and practical set of numbers.
So.. I soon found that I loved the S3s to bits. I liked their overall sound balance, but mostly I loved their speed and agility. I've said more than once on here that I've not heard a speaker with similar balance that can keep up with Ashkenazy playing Mozart piano without falling over itself. The S3 does so with ease.
The downside I faced was that I have space issues, such that I can't position the S3s for ideal bass response. So.. it was stands..a Sub, or something else..
The S3 manual says " the Studio 3 will sound at its best when mounted on high mass, floor keyed supports approx 60 cm high." I'd take issue with 'floor keyed' where suspended floors are concerned..but it works for solid floors...and in the context of this discussion the recommendation is for high mass.
I explored various quality high mass stands, but when Rogers came up with the AB1, I asked if they could work with the S3. Andy Whittle told me yes, and that the different crossover needed for S3 was already worked out., but Rogers new Chinese owners had vetoed production, presumably due to much smaller potential volume sales of S3.
Whatever, Andy made me a pair.
They add sufficient bass weight to compensate for positioning issues, go louder as an overall system, relieve the S3 of some of the load of dealing with the LF end, further enhancing clarity/speed, and of course also also as stands, which, with the addition of granite bases to replace the rather Wimpish Rogers AB1 bases, also comply with Rogers' recommendation for high mass stands.
Also worth mentioning that your description of the AB1/AB3, is more than a little derogatory. It is far more than an 'MDF box with a driver in it.'

 

[Del monaco]

I had casters on my rack for a while. Seemed to make little difference to the sound compared to the spikes I used at the start. It made it a hell of a lot easier to move the kit around though. Measurements are only interesting if you can hear their impact. If not, who cares?

 

[Chops54]

I modified my IMF stands to take nylon rollers. They protrude some 4mm from the bottom rail so you don’t notice them even on laminate flooring. The speakers are just so much easier to move now and I can’t honestly say they sound any different.

 

[Tony L]

I'm not going to insist that you are incorrect about the possibility of a cabinet moving backwards, as a cone pushes forward. I see your point about 'self cancellation' and of course I'm also aware of inertia, but I'd surmise that the forward motion of a cone working against ambient pressure in the room is different to the cone moving back to 'rest'.

It isn’t “going back to rest” (that’s the middle zero db point), a loudspeaker driver is an AC device, the negative wave cycle just as important as the positive. Look at an audio waveform in Audacity or whatever in relation to the zero crossing point and you will understand it better. It is also a broadband device, i.e. it is simultaneously handling all frequencies (within its crossover range).

Surely the cone behaves aerodynamically differently going forward and backwards simply because it is a cone, not a flat surface?

A moving coil driver is usually a cone or dome due to that structure being inherently more rigid, stable, and lightweight than a similarly stiff flat surface. It still handles both the positive and negative phases of the AC audio waveform. If there was an imbalance here you would very clearly hear it. One can argue a panel such as an ESL is a superior design conceptually, but every speaker pushes and pulls equally to recreate an AC audio waveform. Even omnidirectional drivers such as MBLs.

PS For clarity: again I am not arguing there is no vibration transmitted to a cabinet, even on occasion amplified by them, I am just calling ‘bullshit’ on the audiophile misconceptions as to its explanation and the simply laughable idea of “rigid” stands. It has far more to do with cabinet resonance and in well designed speakers is deliberately engineered to be non-destructive sonically. All materials resonate, good design factors this and negates the impact. Cabinet resonance is a fairly narrow band affair, just the frequency the box panels vibrate, e.g. someone thinking a pair of stands “feel rigid” or whatever does not mean they are stable at this specific audio-band frequency, and in some situations they may even amplify it.

 

[Sue Pertwee-Tyr]

Just worth remembering that there has to be enough structural borne vibration to create an AUDIBLE resonance from the floor.
Keith

Bollocks

 

[dalryc]

Just take a punt on some M6 or M8 threaded castors for about £15 or £20 from Amazon and take a listen and spin - it doesn't need to be complicated.