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]

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.

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]

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]

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]

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]

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.

 

[planet10]

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.

Assumming 1/2" material that would work...

dave

 

[needmorstuff]

for my ease of construction would it be ok to use the manufactured aperiodic vents from either scanspeak or dynaudio

 

[planet10]

for my ease of construction would it be ok to use the manufactured aperiodic vents from either scanspeak or dynaudio

They are too large abd don't afford any tuneability.

These are like having a one port fits all boxes. As such i'm not very keen on them.

dave

 

[needmorstuff]

They are too large and don't afford any tuneability.

These are like having a one port fits all boxes. As such i'm not very keen on them.

dave

good to know, I shall follow the planet 10 design.