Small Fostex Bass reflex

Hello since I have been having so much fun with my OB speakers I forgot to post pics of my small 12liter Fostexfe126e in 1/2" solid pine BR enclosures.The port is 2" x 4" don't ask what they are tuned too??? They do sound great though with surprising bass from the fe126e.They are 9.5" square...I know square...but I found it helps reinforce the bass.
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rjbond3rd

Member
2007-01-24 2:28 pm
Hi audiophile36, nice! I also work in solid pine. Is that an oil finish? Looks excellent.

Regarding the cube shape and bass response, I don't think the cube shape per se would give you a boost there.

Assuming internal dimension is 8.5 inches cubed, I think you would have a resonance of around 1400 Hz and perhaps multiples of that. Also, maybe at 1/4 of that, namely 350Hz.

Not sure though as I am a completely newbie. Maybe one of the experts can chime in?
 
rjbond3rd said:
Hi audiophile36, nice! I also work in solid pine. Is that an oil finish? Looks excellent.

Regarding the cube shape and bass response, I don't think the cube shape per se would give you a boost there.

Assuming internal dimension is 8.5 inches cubed, I think you would have a resonance of around 1400 Hz and perhaps multiples of that. Also, maybe at 1/4 of that, namely 350Hz.

Not sure though as I am a completely newbie. Maybe one of the experts can chime in?

Hello,
Yes that is a Boiled Linseed hand rubbed oil finish.The internal dimensions are actually 9 inches cubed.You ever noticed how perfectly square listening rooms usually have boomy bass aka "boost bass" ...it's because of standing waves which normally is a bad thing,but the low QTS Fostex driver benefits from a little acoustical EQ'ing.It actually seems to boost midbass giving the impression of "more" bass.
 
audiophile36 said:

The internal dimensions are actually 9 inches cubed.You ever noticed how perfectly square listening rooms usually have boomy bass aka "boost bass" ...it's because of standing waves which normally is a bad thing,but the low QTS Fostex driver benefits from a little acoustical EQ'ing.It actually seems to boost midbass giving the impression of "more" bass.

Eigenmodes (aka standing waves) are half WL in nature with both even and odd order harmonics, ergo ~13560"/sec/2/9" = ~753.33 Hz, ~1506.66, ~2259.99, 3013.32 Hz, etc., and since it's a cube, all the modes will sum in amplitude, making the nulls deeper and peaks higher gain. Considering the BW involved I fail to see why it would help with the mid-bass/bass BW. The port's close proximity to the driver will though, tuning the cab higher than predicted.

GM
 
GM said:
Eigenmodes (aka standing waves) are half WL in nature with both even and odd order harmonics, ergo ~13560"/sec/2/9" = ~753.33 Hz, ~1506.66, ~2259.99, 3013.32 Hz, etc., and since it's a cube, all the modes will sum in amplitude, making the nulls deeper and peaks higher gain. Considering the BW involved I fail to see why it would help with the mid-bass/bass BW. The port's close proximity to the driver will though, tuning the cab higher than predicted.

GM

I don't know how it works .but I have made the enclosures with different dimensions while still maintaining the 12 liter spec and the bass is not as pronounced as with the cube...maybe it is the ports closer proximity to the driver????
 
MikeR said:
Those look a lot like the ones for sale on Audiogon.

http://cls.audiogon.com/cgi-bin/cls.pl?spkrmoni&1213097963

Yes I am selling them on Audiogon...I have sold 5 pair on Audiogon over the past year or two and the owners love them.Audiogon member B_gentry favorably compares them to his Lowther Medallions.I also made pair for a customer in the pre finished .38cu PartsExpress cabinets and that customer recently ordered a pair in the solid pine cubes and preferes them to the MDF PartsExpress cabinets.
 
boiled linseed looks great when fresh but....

Those pine boxes look great now, but I think you will be disappointed as they yellow in time from using boiled linseed oil.

I have found using boiled linseed on hard maple and oak turn into a very disappointing color as the linseed oil darkens. I don't see how pine will avoid this phenomenon. Someone correct me if I am wrong.

OTOH, this oil works great on dark woods like black walnut IMO.
 
mus said:
I'm just wondering is solid pine much better than MDF? I mean for the FE126/FE127.

MDF is not a good material to build boxes out of IMHO.

Pine seems to have a character that many people seem to like, but like any solid can change shape and crack with changes in humidity. I'd suggest void free plywood as the material of choice (without going nutso)

dave
 
Re: boiled linseed looks great when fresh but....

rcavictim said:
Those pine boxes look great now, but I think you will be disappointed as they yellow in time from using boiled linseed oil.

I have found using boiled linseed on hard maple and oak turn into a very disappointing color as the linseed oil darkens. I don't see how pine will avoid this phenomenon. Someone correct me if I am wrong.

OTOH, this oil works great on dark woods like black walnut IMO.


I actually like the yellowish look once they age.