Small box for FE103 - ML TL or ML TQWT? - diyAudio
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Old 22nd July 2004, 03:45 PM   #1
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Default Small box for FE103 - ML TL or ML TQWT?

I have done the simulation for a small box base on Martin King's mathcad sheet (a big thank you, Mr King )

The result of the ML TWQT is attached. Any comments on this?
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Old 22nd July 2004, 03:48 PM   #2
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Here is the result for ML TL. The curve is a bit smoother. It seems this is better than the TQWT box.
I also notice the port diameter can makesa very big difference in the ripple.
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Old 22nd July 2004, 04:39 PM   #3
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I'd like to offer a comment; It seems for both of these that the bass levels start to fall away prematurely. It looks as though you are trying to hit 50 hz, and as a result the response below 100 hz is depressed by at least 3 db.

I made a similar mistake on my project (bigger mistake, yours might not hurt so badly) in underestimating the effects of a depressed bass response. The rule of thumb that I heard was that this sort of enclosure can play lower than the driver's Fs (not necessarily a good idea)- all the way down to 0.7*Fs.. any lower than that is a much worse idea. I think that you might want to consider moving your target cutoff a bit higher; to 60, 70, even 80 hz- and use a small sub.
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Old 22nd July 2004, 05:11 PM   #4
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Hi Joe,

thanks for the reply, but I am not trying to go low, but rather, try to have a smooth roll off as I have notice that there will always be quite a bit of room gain under 100Hz. A flat curve to 80Hz and sharp roll-off is definitly not desirable. At lease in my case.
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Old 22nd July 2004, 07:17 PM   #5
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We discussed this not too long ago. Here's the thread.
TQWT for the TB W3-871S
Many of us have concluded that the classic TL design is preferred unless the driver, for whatever reason (Q etc.) performs better in a tapered pipe.
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Old 23rd July 2004, 08:04 PM   #6
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See the recent threads about the "Locust 1.0". It's a MLTL using the FE107E, which is like the 103, but with shielding and a somewhat smoother response.

I'm listening to a pair right now, augmented with a sub crossed over at about 70 Hz. Good stuff.
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Old 23rd July 2004, 08:13 PM   #7
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Quote:
Originally posted by Dave Jones
See the recent threads about the "Locust 1.0". It's a MLTL using the FE107E, which is like the 103, but with shielding and a somewhat smoother response.

I'm listening to a pair right now, augmented with a sub crossed over at about 70 Hz. Good stuff.

They are real easy to build, using 3/4" material all around. The port is just a 1" hole in the front panel. Internal dimensions are H 19.5", W 4", D 5.5". Driver offset is 6". Port (hole) near the bottom.
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Old 23rd July 2004, 08:29 PM   #8
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Quote:
Originally posted by ChuckT
Hi Joe,

thanks for the reply, but I am not trying to go low, but rather, try to have a smooth roll off as I have notice that there will always be quite a bit of room gain under 100Hz. A flat curve to 80Hz and sharp roll-off is definitly not desirable. At lease in my case.
I'm using the Locust I's in a small room, and they are not at all boomy in the 70-100 Hz range. I have a peak at around 200Hz, but I think that's from a wall reflection. Those little speakers are simply not going to deliver loud, deep bass regardless of what kind of box you put them in. They are only 4" in diameter, and have a tiny xmax. I suspect that trying to stretch their low end response below 60 or 70 Hz would just create problems. I tried using them with some EQ on the low end, and they did not appreciate it! Now I use a sub with them, but on a lot of program material the little speakers sound fine all by themselves.

D.
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Old 24th July 2004, 07:06 AM   #9
navin is offline navin  India
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nice designs dave. do you have any pics? those boxes 21" tall 7" deep 5.5" wide look like they can be made a bit smaller if i use 6mm AL instead of 21mm wood.

perfect to wall hang on either side of a plama tv.

now i was thinking of use 2 x 103 or 107 so that the BSC filter can be avoided and to get more bass SPLs.

maybe upfiring the second driver...
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Old 24th July 2004, 02:03 PM   #10
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Navin, for bipole try
L=24"
So=46.75"
Sl=46.75"
Port=1"radius. 1"length
Drivers at 50% of L
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