Css Fr125sr 4.5

[needmorstuff]

Hi All,

I am trying to design a set of 5 speakers for my home cinema.
They will all use a single CSS FR125SR 4.5" Fullrange Driver.

The box will be 12" high x 7" wide and 6" deep.

I have modeled with winisd and with a 45mm diameter port that is 17cm long the box tunes to about 80hz.

Could someone run the numbers for me as I am an absolute winisd newb and want to get things correct before I cut the wood.

thanks for any help.

[sreten]

Hi,

Qts = 0.6 = venting is a no-no.
Assuming 3/4" stock box = 4L. (1/2" = 5L)
Sealed and stuffed is your only sensible option.
Venting at 80Hz gives a 4dB bass peak.

/sreten.

[sdclc126]

Are you going to build a sub? You'll need one!

[planet10]

I have found that these drivers work best in an aperiodic box. I'd suggest building one of -- or a variation of -- the recommended 7 litre bass reflex and then stuffing the port to taste. Stuff it sufficiently and it will be sealed.

dave

[needmorstuff]

Originally posted by sreten
Hi,

Qts = 0.6 = venting is a no-no.
Assuming 3/4" stock box = 4L. (1/2" = 5L)
Sealed and stuffed is your only sensible option.
Venting at 80Hz gives a 4dB bass peak.

/sreten.

Originally posted by sdclc126
Are you going to build a sub? You'll need one!

thanks for the replies :-)

only vented the box as I assumed it gave a lower extension and have seen it done by vikash.

yes I am using a sub - at the moment it will be an svs sb12+

I really wanted the speakers ot be good down to 80hz - is this achievable given my design constraints? the box will be 3/4" MDF but if 1/2" is ok then I am happy to use that to give the extra volume.

[planet10]

Originally posted by needmorstuff
I really wanted the speakers ot be good down to 80hz - is this achievable given my design constraints? the box will be 3/4" MDF but if 1/2" is ok then I am happy to use that to give the extra volume.

Sealed or aperiodic should get you down to 80 hz with better control than a BR.

1/2" ply or HDF is better than 3/4" MDF (you won't find me using MDF at all)

dave

[needmorstuff]

Originally posted by planet10
I have found that these drivers work best in an aperiodic box. I'd suggest building one of -- or a variation of -- the recommended 7 litre bass reflex and then stuffing the port to taste. Stuff it sufficiently and it will be sealed.

dave

7 litres is fine for my centre channel but the other 4 channels are limited to 4 litres..

[planet10]

Originally posted by needmorstuff



7 litres is fine for my centre channel but the other 4 channels are limited to 4 litres..

4 litres is just a tad small... there are 2 different 4.5 litre aperiodic designs on the p10-hifi site. I'd recommend going all the way round with something like that.

dave

[needmorstuff]

Originally posted by planet10



4 litres is just a tad small... there are 2 different 4.5 litre aperiodic designs on the p10-hifi site. I'd recommend going all the way round with something like that.

dave

If i am going with 1/2" material then my enclosures can be 5 litres :-)

I have been on the site all day! excellent site. I will be wall mounting the other 4 speakers so they will need to be 5 litres but slimmer than the designs on the site.. I need them to be quite low profile to fit in with my room (read wife)

The shape I am after is like (dare I say it) the kef ace series.

With 5 litres in a non aperiodic design will they get down to 80hz?

[needmorstuff]

apologies- just found the page (i think).. I could go with the a slimline aperiodic design of roughly (external) 12"high 8"wide (bottom) 5" deep to give me the 4.5 litres I require.