Help with speaker stand design please...

My girlfriend has decided my stands are too tall (they're only 1 foot as it is) as they make the speakers too imposing in the new shared lounge. So I'm in the middle of experimenting to make some much shorter alternative stands, to see if they will sound ok. If it all turns out to be a disaster I'll go back to the original stands. I would like some input for ideas...

What I have ordered to be made so far is just the base platform, laser cut from 20mm thick solid steel, measuring 330 x 450 mm, with tapped holes to accept either three or four carpet piercing spikes per speaker. This will be the foundation baseplate that I can try different supports between this and the speaker itself (PMC IB2). Now what would be the best thing between the plate and speaker?...

1. Bluetak?
2. Some sort of specialist cone or spike?
3. Some kind of thin metal legs to try and divert energy out of the speakers corners?
4. Squash balls cut in half?

I found these on the net...any thoughts?...Thanks ....


https://www.audiophilecandy.com/prodet.asp?pcode=I-CLE-RDC5&rel2=I-CLE&0=More+Info

 

new girlfriend?

Bob

 

...between the baseplate and speaker?

 

I seem to remember reading of a home made stand that consisted of two sheets of MDF which sandwiched ballbearings? Did that work? Is it appropriate in this instance and if so can anyone else remember how it was put together?

or

didn't Steve of 7th Veil use superballs balanced on doorstops

 

Ooh dear, that really will screw up the sound - have you tried the position already?

 

Not yet. I once tried it with the cabinets just sitting on the carpet and the bass was messed up a little, unsuprisingly. I hope to achieve a sound very similar to the original stand setup, but with it being 6 or 8 inches shorter. The lower height with respect of the tweeter height is ok, as our sofa is pretty low for slouching.

 

Paul, it's the coupling of the bass unit to the floor that's the problem, and to be honest, given the bass boost inherent in the PMC's, raising them even higher would be prefereable from an accuracy POV. Put simply, the floor is a boundary just like the rear wall. Bass is omnidirectional so it cannot tell the difference between floor and wall. Therefore as you move your bass unit closer to the floor, you have the same effect as when you move them closer to the rear wall. Hence loudspeaker manufacturers make stands that they feel provide the correct bass balance.

I really can't see the value in spending so much on such a good pair of loudspeakers and then compromising with the position.

 

I don't want to mess the sound up, so if it doesn't work out I'll just use the original stands. It's just an experiment really, so at least I can say I tried to keep her happy.

Thanks for the advice though. It seems your saying I need to keep a set distance from the floor surface. I wonder if a trench in the lounge would help

 

Try them upside down then, to raise the bass port/driver. Tip them back to aid the tweeter with some junk mail wedged under the front edge

 

The main problem lowering the speakers is the tweeter height, idealy this needs to be at ear level [of your listening position]. Too far off the dispersion axis of the tweeter, can't remember which one pmc use, will lead to a variety of compromises.

If the pmc only use a pucker stand of 12" I can see a number of alternatives.

The mdf cross quick and dirty.......not my fav diy

The down pipe stand..... cut the pvc down pipe to length make a base plate secure pipe and fill with sand or concrete, and cap. use at least three, but five or seven pipes will work, if the speaker base is big enough.

Stone stands, take trip to the garden centre and look at small plinths the sort they use for big pots. Or get a stone murchant to cut you some to fit off cuts are reasonable.

Get a thick stone 3-4 " base cut to the size of your speaker base, attach via the spike threads. This will increase the cabinet mass, lower the centre of gravity etc , all good things for speakers. Then look at the floor interface long adjustable cones see parts express.

Off the wall suggestion, use a 18mm mdf sandwiched with foamed butyl rubber, several layers will build up to the hieght you need. This will be different from the convential stands...some speakers react rather well ......others don't

Make a box the size of the speaker base .....filll box with tennis balls [new] and float a top plate or speakers straight on to balls. This should isolate that pescy speaker floor boundary. Make certain the speaker does not touch the outer box.

Your only really limited by your imagination ....and of course how the speaker sounds on its new stands.

 

I say new gurl friend
Or you can always stand up to her be masterful she'll melt in your arms!

 

...I remember numerous conversations I had with Roger Stone of iF Designs who had experimented with just about every type of material in as many different combinations over the years who stated that sheet steel on it's own is a terrible material to use in a stand design as it introduces it's own 'ringing' effect (noise).

Rogers reference stands uses a combination of materials but where he used steel (for the top-plate), he designed a special 'sandwich' where thin layers of sheet steel were separated with another substance (can't remember what it was). A simple finger flick test shows that pure sheet steel rings like a bell whereas his plate does not.

Just another idea to throw in the equation,...personally I would be telling the girlfriend that you came with the audio kit so like it or lump it! hehehe

...if you were to develop your negotiation skills you would get your girlfriend to be spending more time thinking about the sonic qualities rather than the visual. LOL

 

It did occur to me that a thinner sheet of steel could ring under certain conditions. That is why I specified very thick 20mm material, which will weigh an absolute ton. I can't see that ringing unless I belt it with a sledge hammer. However your suggestion of isolatiing the steel seems like a sensible point, just to be on the safe side. I could sandwich another medium (perhaps Dynamat?) between the steel baseplate and an upper surface made from 25mm marine ply. This material looks lovely when it's properly finished, highlighting the stripes.

I also think angling the speaker slightly will reduce the effect of them being lowered in the first place, from the tweeters point of view anyway. I have some adjustable threaded and balljointed feet which could be used for this application.

If all this fails I always have the original stands, or the junk mail suggestion

 

I hope she's worth the hassle, Paul

DT

 

I've spent a few days with my new stands now. I'm pretty happy with the results so far. It still sounds controlled, with a very mild sub bass lift, which sounds especially lovely when the volume is lower. The look pretty cool too. I may swap back to the originals in a month to see which I prefer longterm.

(In the end it was 20mm black steel with dynamat layers, triple spikes, adjustable legs to angle the speaker up a touch, plus a spot of blutak on the speaker cabinet edges).

 

Your description sounds rather like the stuff from these guys http://www.sounddeadsteel.com who have just about the worst website in history
If it's not too costly I might try and get some.

 

Paul,

Out of interest, what were the original stands you were using? I need some stands about 12-15" high for a pair of speakers that measure 350mm wide by 450mm deep and even Atacama's SL series will look a bit small under them!

Adam.