Cal,
You will find some T/S measurements here, scroll downt to the "Coral Corner":
http://de.geocities.com/peter_rehkop/system.html
Grab the excel file. (no, it's not my homepage)
Some more here:
(from: http://www.rahaso.de/foren/msg.php?f=audiotreff_fullrange&x=1&idx=10946&)
Coral Beta-8, TSPs
Treiber 1 Treiber 2
Sd (cm2) 214
Re (Ohm) 6.85 6.86
Fs (Hz) 53.5 51.4
Qe 0.47 0.43
Qm 4.78 5.06
Qt 0.43 0.40
Vas (l) 79.9 75.2
Mms (g) 7.17 8.29
Cms (mm/N) 1.23 1.16
B*L (N/A) 5.9 6.5
Rms (kg/s) 0.5 0.5
Le (mH) 0.39 0.41
/Peter
You will find some T/S measurements here, scroll downt to the "Coral Corner":
http://de.geocities.com/peter_rehkop/system.html
Grab the excel file. (no, it's not my homepage)
Some more here:
(from: http://www.rahaso.de/foren/msg.php?f=audiotreff_fullrange&x=1&idx=10946&)
Coral Beta-8, TSPs
Treiber 1 Treiber 2
Sd (cm2) 214
Re (Ohm) 6.85 6.86
Fs (Hz) 53.5 51.4
Qe 0.47 0.43
Qm 4.78 5.06
Qt 0.43 0.40
Vas (l) 79.9 75.2
Mms (g) 7.17 8.29
Cms (mm/N) 1.23 1.16
B*L (N/A) 5.9 6.5
Rms (kg/s) 0.5 0.5
Le (mH) 0.39 0.41
/Peter
wow ... that's faster than me, haven't got time to chech T/S yet, no wonder I coudnlt find it.. it's in german.
thanks guys,
Now what .. ?
I saw the sealed, ported box from the reccomendation Coral it self but I don't like them.
I like Big, Horn.... well not to big, about 2 meter tall is my size !
Scottmoose,
with bruce design box, no need mods ata all ?
what do you mean by run mathcad sim ?
sorry my basic question....
let me know what you can do with mathcad .
those T/S can be trusted ? I think thay can, correct me if I'm wrong, they tested 7 times and the average is the number that I should pick... right ?
still confuse which box I should build ? help...
cal
thanks guys,
Now what .. ?
I saw the sealed, ported box from the reccomendation Coral it self but I don't like them.
I like Big, Horn.... well not to big, about 2 meter tall is my size !
Scottmoose,
with bruce design box, no need mods ata all ?
what do you mean by run mathcad sim ?
sorry my basic question....
let me know what you can do with mathcad .
those T/S can be trusted ? I think thay can, correct me if I'm wrong, they tested 7 times and the average is the number that I should pick... right ?
still confuse which box I should build ? help...
cal
Don't miss the the excel sheet, what's the excel shetet data average for ?
why they test the 8 different driver for ?
this data is what I need right ?
Some more here:
(from: http://www.rahaso.de/foren/msg.php?...&x=1&idx=10946&)
Coral Beta-8, TSPs
Treiber 1 Treiber 2
Sd (cm2) 214
Re (Ohm) 6.85 6.86
Fs (Hz) 53.5 51.4
Qe 0.47 0.43
Qm 4.78 5.06
Qt 0.43 0.40
Vas (l) 79.9 75.2
Mms (g) 7.17 8.29
Cms (mm/N) 1.23 1.16
B*L (N/A) 5.9 6.5
Rms (kg/s) 0.5 0.5
Le (mH) 0.39 0.41
why do I need other's data like the 7 drivers on the excel ?
I don't ?
cal
why they test the 8 different driver for ?
this data is what I need right ?
Some more here:
(from: http://www.rahaso.de/foren/msg.php?...&x=1&idx=10946&)
Coral Beta-8, TSPs
Treiber 1 Treiber 2
Sd (cm2) 214
Re (Ohm) 6.85 6.86
Fs (Hz) 53.5 51.4
Qe 0.47 0.43
Qm 4.78 5.06
Qt 0.43 0.40
Vas (l) 79.9 75.2
Mms (g) 7.17 8.29
Cms (mm/N) 1.23 1.16
B*L (N/A) 5.9 6.5
Rms (kg/s) 0.5 0.5
Le (mH) 0.39 0.41
why do I need other's data like the 7 drivers on the excel ?
I don't ?
cal
You test a large number of drivers because no two drivers are exactly the same. Generally figures + / - 5% of the average are considered acceptable. That's why you will frequently see the phrase 'pair matching'. Specialist sellers like, for example, Planet10 hifi (Dave), Validator (Thorsten) etc will test a batch of drivers themselves and match them into pairs who's characteristics are as closely aligned as possible.
MathCad refers to Martin J. King's seminal MathCad worksheets, which I use in designing every speaker I come up with. There's a variety -horns, TLs, isobaric, sealed box, open baffle etc.
I ran a quick check. Q of the Coral is a little high to be ideal, so the low frequencies roll off a little below 100Hz, but in some ways that's probably a good thing as Bruce could get a bit hefty with some drivers unless you're careful over setup. You should get a solid 40Hz. The Schmacks horn I've never modelled in MathCad -I really should look into it at some point. It's got plenty of internal volume, so it should do well -by the above accounts it works well enough.
MathCad refers to Martin J. King's seminal MathCad worksheets, which I use in designing every speaker I come up with. There's a variety -horns, TLs, isobaric, sealed box, open baffle etc.
I ran a quick check. Q of the Coral is a little high to be ideal, so the low frequencies roll off a little below 100Hz, but in some ways that's probably a good thing as Bruce could get a bit hefty with some drivers unless you're careful over setup. You should get a solid 40Hz. The Schmacks horn I've never modelled in MathCad -I really should look into it at some point. It's got plenty of internal volume, so it should do well -by the above accounts it works well enough.
thanks guys,
now I'm interested in MatchCad,
1. how you test/calculate for this case ? any screen capture ?
2. could someone give me step by step how to do this case with mathcad, I mean like tutorial captureing the screen ?
3. any sample mathcad file ?
scottmoose,
you said final test olways in after the building, so... after building what we can do is play the RTS ? then we know which freq. is "not there" right ?
you said again that every box design you calculate with mathcad, suppose I design the enclosure with Sphere ( no corner at all), this idea can be calculate with mathcad right ?
how do we know that this design will work ? I mean will this sound better than other design ?
now I'm interesting in designing my own.
now I become greedy
I think my friend has MatchCad .
cal
now I'm interested in MatchCad,
1. how you test/calculate for this case ? any screen capture ?
2. could someone give me step by step how to do this case with mathcad, I mean like tutorial captureing the screen ?
3. any sample mathcad file ?
scottmoose,
you said final test olways in after the building, so... after building what we can do is play the RTS ? then we know which freq. is "not there" right ?
you said again that every box design you calculate with mathcad, suppose I design the enclosure with Sphere ( no corner at all), this idea can be calculate with mathcad right ?
how do we know that this design will work ? I mean will this sound better than other design ?
now I'm interesting in designing my own.
now I become greedy
I think my friend has MatchCad .
cal
Scoot,
" Should do. If you want a tweak, increase the cabinet width by 1in which should give a bit more volume, which the Coral likes. Otherwise it should perform decently."
increse the width by 1 inch, so it become 11 inch right ?
just make sure, so I think I decide to build this Bruce 1.1
do you think thicker MDF will be better ?
cal
" Should do. If you want a tweak, increase the cabinet width by 1in which should give a bit more volume, which the Coral likes. Otherwise it should perform decently."
increse the width by 1 inch, so it become 11 inch right ?
just make sure, so I think I decide to build this Bruce 1.1
do you think thicker MDF will be better ?
cal
There is a Schmacks version made in France where the driver is situated in the side on the cabinet and they have some helmholz resonantor to even out the response.
Jericho 08 in Hobby Hi-Fi 02/2008, has more elegant proportions than the squat Schmacks horns. 0.4 m wide 1 m high and 0.5 deep. I plan to build these for other drivers.
Any "best" cabinet is a compromise.
8" fullrange drivers tend to have very light cones and short cone motion (to get any high range response). To get the most bass out of a very short stroke a horn like the Jericho 08 is "best". However, the thin cone makes the driver unusually sensitive to internal reflections messing up what the cone is doing. Jericho has many surfaces very close to the driver and not that much damping material.
A big welldamped closed box will give minimal internal reflections. But then you will need a subwoofer below 80 Hz.
A big reflex box will add some bass for some tradeof in internal reflection.
So my best cabinets
Small room: Bass reflex
Large Room. strickt fullrange, horn, here it really depends on how large horn you can accept in your room. Build as big as possible and not smaller than the Jericho 08. Smaller horns than that is just pipes.
Large room, full range above 80 Hz; Closed box and subwoofer
Jericho 08 in Hobby Hi-Fi 02/2008, has more elegant proportions than the squat Schmacks horns. 0.4 m wide 1 m high and 0.5 deep. I plan to build these for other drivers.
Any "best" cabinet is a compromise.
8" fullrange drivers tend to have very light cones and short cone motion (to get any high range response). To get the most bass out of a very short stroke a horn like the Jericho 08 is "best". However, the thin cone makes the driver unusually sensitive to internal reflections messing up what the cone is doing. Jericho has many surfaces very close to the driver and not that much damping material.
A big welldamped closed box will give minimal internal reflections. But then you will need a subwoofer below 80 Hz.
A big reflex box will add some bass for some tradeof in internal reflection.
So my best cabinets
Small room: Bass reflex
Large Room. strickt fullrange, horn, here it really depends on how large horn you can accept in your room. Build as big as possible and not smaller than the Jericho 08. Smaller horns than that is just pipes.
Large room, full range above 80 Hz; Closed box and subwoofer
Dear,
Did you ever get all parameters of these Coral Beta 8 speakers complete?
I would like to have them too as I yust got to a almost new set of these beauties.
Mariogert
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