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ballsingtripp 9th April 2009 10:35 AM

Coral Flat 5 t/s
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I've just bought a pair of Coral Flat 5's on ebay..does anyone have any t/s parameters? I was only able to find some info on the Flat 6's. Their DC resistance or a way to measure it would be especially helpful. Unfortunately I can't afford a woofer tester at this point.

aroS3 9th April 2009 12:15 PM

Coral Specs
2 Attachment(s)
Not much...

ballsingtripp 9th April 2009 02:42 PM

Ah..still helpful, thanks!

I'm not sure if these are II's or not..

GM 10th April 2009 04:50 AM

FWIW, a starting point.............

Using the II's minimal specs and erroneously using Qo as Qts, then with Mo, Vas = ~12.97 L, ergo a max flat alignment is theoretically ~35.24 L tuned to ~51 Hz with a ~5.08" diameter hole if a 19 mm baffle is used.


ballsingtripp 10th April 2009 04:31 PM

Hmm..wish I knew what I was talking about. :(

Is there a way to determine Vas from those specs?

GM 10th April 2009 07:10 PM

Not accurately, unless the Mo, Fs, effective radius specs are. As I said, I made some erroneous assumptions to derive what all I calculated, so I chose to assume Mo = Mms to calc Vas. FWIW, the calc'd Vas is within an acceptable range for the driver size, Fs.

WRT the box calc, I have some experience with the simple Qo calculations and since they're fairly accurate in the range around ~0.4 Qts, I chose to assume Qo = Qts figuring at worst, the box would be too big and/or tuned too low, so with a simple vent hole it would have plenty of tuning flexibility for optimizing it to suit your app. This assumes of course that I used the right specs for your drivers and they are accurate.

All thing considered, I doubt they're even remotely close, but I'd be surprised if you can't make the suggested box work and if turns out to be way too large (or too small, which I doubt unless driving them with a high output impedance amp) you can always make new ones, so suggest you just cobble one together from scrap or other cheap materials, even industrial strength cardboard. Just make sure there's no air leaks before each modification or the effort will be wasted.

Vas = 0.01*po*c^2*Sd^2/((2*PI()*Fs)^2*Mms)


po = 1.21 Kg/m^3
c = 344.43 m/s
Sd in cm^2
Mms is in grams

Note that different programs tend to use different po, c values, so for best theoretical accuracy use the ones for the program.

Bottom line, you want accurate specs you'll have to measure them somehow, whether by someone else, use a woofer tester or do it 'long hand':


ballsingtripp 11th April 2009 12:51 AM

I'm sure these won't be the last enclosures for these drivers, and I was planning on handling it like you said too, so some experimentation is fine. :)

Makes sense now..thanks for the help! :D

GM 11th April 2009 01:40 AM

You're welcome!

Please let us know what you wind up with.........


CFT 15th April 2009 04:20 AM

I am interested to know too, I have a same pair as well :D

Mine have Coral 5A II, 3W nomimal, 8W max....on the back. (not sure if they are the Flat 5 II either :xeye: )

I have tentatively made some mini OBs for them....eventually with active xo to be mated with 5" woofers on hand ...

ballsingtripp 15th April 2009 04:28 AM

Haven't actually gotten mine yet, but I hope they can handle more than 3W. :confused:

The auction said 92dB 1w/1m...

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