Re: [Harp-L] Speaking of amp stands...

[Vern <jevern@xxxxxxx>]

It is easy to over-estimate the directionality of an amp.  The mental image of a beam of sound emanating from the front of the amp like a beam of light is unrealistic.  Because  the speakers are small with respect to the the wavelengths of sound being produced, diffraction* causes the sound waves to disperse almost equally in the hemisphere to the front of the amp.  A better mental image would be to think of throwing the amp into a calm lake and watching the resulting waves.

Turning the amp at various angles to a sound level meter and plotting the readings would show the directionality of the amp.  A cruder experiment would be to determine the minimum angle that could be detected by a blindfolded listener.   

* diffraction:  see  http://hyperphysics.phy-astr.gsu.edu/hbase/sound/diffrac.html

Vern

On Jan 30, 2011, at 1:25 AM, Tom Skailes wrote:

> Chris - This stand did look the best of the bunch, but as far as I can tell, is not available in the UK - unless anyone knows of a source?
> 
> JP - if I get the tilt legs I'll be in touch for the reference measurements from the super as I have nothing to go by otherwise. I'm guessing that the amp tilts back a fair angle when set back on the legs - the amp controls will be less accessible, but that's a downside of the amp design. Does the room still get the sound ok, and do the tonal improvements work for the room as well?
> 
> Thanks,
> Tom
> 
> 
> 
> On 30/01/2011 01:22, Cljdm@xxxxxxx wrote:
>> Hi all,
>> I can't say enough about this amp stand, with the optional mic boom. Also packs nicely.
>> http://accessories.musiciansfriend.com/product/Musicians-Gear-Deluxe-Tripod-
>> Amp-Stand-with-PosiLok-Combo-Boom-Arm?sku=431053
>> And I also agree, that the sound is improved once the amp is off the floor.  The highs and lows seem to surround the amp, so to speak. I just notice an improved sound, hard to explain.
>> Best,
>> Chris Mastakas
>> 
>> 
>> 
>> In a message dated 1/29/2011 7:51:21 P.M. Eastern Standard Time, hvyj@xxxxxxx writes:
>> 
>>    Tom,
>> 
>>    I did this to my RI Princeton Reverb with a set of 14" tilt back legs
>>    because i like how the tone opens up on the PRRI when it' s tilted
>>    back. And i don't like carrying around an amp stand.
>> 
>>    Done properly, I think it's a great mod that favorably affects the
>>    tone of the amp more than one might think.
>> 
>>    Hope this helps.
>> 
>>    JP
>>