Parts express Totally tubular questions.

[lapoltba]

HI all,

I saw this project on Parts express' website and i thought it was very interesting.

http://www.partsexpress.com/projects...lar/index.html

I was wondering if it would be possible to change these to a sealed design. I planned on using a sub with them as well as an active crossover. I like the idea of an MTM design using pvc its just a cool looking design.

thanks.

-Brian

[sreten]

Hi,

Of course you can make them sealed, you can also
reduce the length of each pipe by 50% if you want.

Active crossover - your going to need it as the crossover design is
poor and the speaker apparently has no baffle step compensation.

checkout : http://www.zaphaudio.com/BAMTM.html

/sreten.

[sdclc126]

Originally posted by sreten
Hi,

Of course you can make them sealed, you can also
reduce the length of each pipe by 50% if you want.

Active crossover - your going to need it as the crossover design is
poor and the speaker apparently has no baffle step compensation.

checkout : http://www.zaphaudio.com/BAMTM.html

/sreten.

Hi streten - how would you correct the crossover design (passive) on the TT? Thanks.

[lapoltba]

what BSC would be needed? as designed, there is a minimal "baffle" so i would think there is minimal effect, and only an effect on the higher frequencies right? Im new to diy speaker building so let me know if im wrong....

I thnik for those particular drivers a .5 cu ft box per speaker is recommended, so basically... pi*(R)squared*length = volume using a 6' pvc pipe.....

3.14 *9*x=.5

x= about 2 inches? seems a bit tiny to me.. lol
i was thinking of a 6 inch pipe about 5 or 6 inches long would be a nice space conserving size. idk how well it would be acoustically though.

[sreten]

Originally posted by sdclc126


Hi sreten - how would you correct the crossover design (passive) on the TT? Thanks.

Hi,

I'd use Zaph's data and the methodology outlined here :

http://www.rjbaudio.com/Audiofiles/FRDtools.html

/sreten.

[sreten]

Originally posted by lapoltba
what BSC would be needed? as designed, there is a minimal "baffle" so i would think there is minimal effect, and only an effect on the higher frequencies right? Im new to diy speaker building so let me know if im wrong....

I thnik for those particular drivers a .5 cu ft box per speaker is recommended, so basically... pi*(R)squared*length = volume using a 6' pvc pipe.....

3.14 *9*x=.5

x= about 2 inches? seems a bit tiny to me.. lol
i was thinking of a 6 inch pipe about 5 or 6 inches long would be a nice space conserving size. idk how well it would be acoustically though.

Hi,

1) - no. The speaker is the baffle, ripple and step are relatively severe.

2) 0.5cuft = 12*12*6 = 864 cubic inches internal.
A 6" internal pipe = 30.5" long.

/sreten.