Room Mode Madness

Before you read this post please note that to understand what I'm babbling about you will need to click the following Room Mode Calculator link and enter the 2 sets of LxWxH dimensions found below. I used Bob Golds Room Mode Calculatorto find some ideal dimensions for a Room within a Room construction i am designing for a vocal booth... or so i thought... The maximum internal dimensions i can achieve with my limited space are: 8'L x 5'W x 7'H. Remember this is a vocal room and will mostly be used just for vocals (so i figure relevant frequencies will maybe go down as low as 85hz to capture the harmonics of a very bassy voice). The "Ideal" dimensions I came up with are: 7'3"L x 4'7"W x 6'9"H I have 3 questions regarding the results of these dimensions when entered into this room mode calculator. 1. The resulting room ratio is 1 : 1.47 : 1.58, these numbers fall close but not exactly within the "Bolt Area" graph that i see in my Master Acoustics Handbook, I dont think its that important but should i be concerned about this? 2. There is a dip around 100 hz in the Bonello graph, I understand this is not desirable, but is it less desirable than using these dimensions: 7'3"L x 5'W x 6'7"H whereby the Bonello curve looks slightly more flat BUT there is a problem with the modes in the 113hz-116hz frequency group (as indicated by the Yellow warning color). These are Axial and Tangental mode problems so i figure they're treatalbe since I plan to treat the walls with wideband absorption anyhow. 3. EXTRA CREDIT Question: The test "Fails" the first formula under the Computed Information > R. Walker BBC 1996 heading but the corresponding linked document states that this formula is for a classical music "listening room" is this a problem for my vocal booth? Should I ignore this line altogether? I would guess the first dimensions I indicated (7'3"L x 4'7"W x 6'9"H) might be the best for my situation acoustically, but in terms of width I would also be loosing 5 inches of already cramped space. And if the probelms caused by the second set of dimensions (7'3"L x 5'W x 6'7"H) are easy to correct, I'd rather have the extra width. Does it even matter that much? I'm driving myself nuts here trying to wrap my mind around this design. Any help totally appreciated. HBomb

mate - in a room that small I wouldn't bother about modes - you'll need to add a lot of absorption to wipe out the room sound. 6ft person would only be 1 foot away from the ceiling which would be the closest wall. BTW - not many voices produce anything under 100hz - that why most mikes have a rolloff at 100hz for voice. cheers john