questions on a FE167 TQWT design.

[AudioGeek]

After more studying... I have decided on a FE167 design.

I was reading a little about these and have decided that the flare shall be out of the top like these:

http://www.melhuish.org/audio/DIYTQ8.html

question is: where do i find out about enclosure dimensions for this style.. ?

Of course I will add an BSC circuit and a zobel network..

any help would be appreciated.

 

[MJK]

Before building a TQWT design, I suggest reading Bob Brines' site for an excellent tutorial on tapered pipe designs. His site is linked from mine and he has a design for the FE-167E already done.

Or you might want to consider my ML TQWT design. The FE-167E is a drop in replacement for the discontinued FE-164 driver. Many people have built this design and provided very positive feedback. Several examples can be seen in my gallery where there are e-mail links so that you can ask the builder questions directly.

Hope that helps,

 

[Nelson Pass]

The dimensions for Terry's enclosure are given in the
text of his article, which are 7 x 14 x 70 inches and he
gives additional details on driver location and internal
baffle.

BTW, it's my experience that if you are out in the room
with such an enclosure (as opposed to the corner or
perhaps against the wall) you should consider turning
them upside down and see what you get. If they are
firing into the floor carpet, you can get a pretty nice effect.
Of course they must be elevated to create an opening, but
you can tune the opening by varying the height.

 

[AudioGeek]

40-1354

Is this RS driver similar to the FE167??

Also, what about stuffing the line?... any rules of thumb?

Thanks!

 

[AudioGeek]

going to use this design:

http://geocities.com/rbrines1/

Click on the straight pipe info.

question is this: this design uses a 5 1/4 driver with throat = Sd and mouth area = 4 Sd.

where are these areas in the diagram?

for a 6in driver like the FE167... how much do I need to increase the size of this enclosure?

Thanks!

 

[MJK]

Is this RS driver similar to the FE167??

No, don't waste your time with the RS driver. The Fostex FE-167E is a much better driver.

Also, what about stuffing the line?... any rules of thumb?

The drawings all show the location and stuffing density. Why would you want to do something different?

question is this: this design uses a 5 1/4 driver with throat = Sd and mouth area = 4 Sd.

S0 = 1 x Sd is at the top of the enclosure, the small pointed and closed end.

SL = 4 x Sd is at the bottom of the enclosure, the larger end with the opening.

Bob's plans show the dimensions at each end and the location of the stuffing.

for a 6in driver like the FE167... how much do I need to increase the size of this enclosure?

To answer this question you will need to rerun the MathCad simulation with the properties of the FE-167E driver. This is a complete redesign of Bob's RS 1354 pipe and will be a bigger enclosure and a different BSC circuit. Are you willing to take on the effort required to redesign the enclosure? I am not sure where you are headed.

 

[Nelson Pass]

Certainly it's easy enough to play with the stuffing location
and density.

I stuff the enclosures to taste. In addition to the vagaries
of the location and room, your own subjective needs need to
be considered.

 

[AudioGeek]

redesign

Yeah... i want to re-design the enclosure.

I am D/L the mathcad software as we speak.

How does the port or slot loading at the mouth area or SL come into play?

For the FE167 the S0 is 20 square inches, SL is 80 square inches.

correct?

The BSC circuit doesn't bother me... I can design that with zobel and baffle step compensation.

 

[MJK]

How does the port or slot loading at the mouth area or SL come into play?

If you look at the cabinet design section of my Project #4, there is a write up that describes how the port works in a ML TL. The same idea is true for the ML TQWT.

For the FE167 the S0 is 20 square inches, SL is 80 square inches. correct?

Looking at the drawing in my Project #2 article.

S0 = 2.5 x 10 = 25 in^2

SL = 14 x 10 = 140 in^2

L = 60 in (height of my enclosure)

r_port = 1.5 in

L_port = 2 in (in my final configuration)

That is what I ended up building.

 

[Bob Brines]

Since my name is getting thrown around here, I guess I should comment.

My experiece is that any driver that will work in a TQWT will work in a rectangular MLTL. The only reason for choosing the TQWT is aesthetic, bacause the MLTL will be much more compact. My current enclosure for the FE167E is 40"x8.5"x8.5", the driver 11.5 down from the top and a 3"x4" port 4.5" up from the bottom. I'll update my web page someday.

These dimensions were chosen to minimize ripple an still get F3 down to 40Hz. Wiht a lining of 1/2" yellow fiberglass, very little additional stuffing is needed.

Before you do the "Bigger is Better" or a scaled up version, run a MathCAD sim on it. You may be surprised.

Bob

 

[Nelson Pass]

At the risk of being jeered at publicly, I will say that I have
had some good results lining my TL's with fiber acoustic ceiling
tiles. They don't absorb much at low frequencies, but they
do a decent job of deadening the higher ones, and still leave
lots of space for dacron or whatever.

 

[planet10]

At the risk of being jeered at publicly, I will say that I have
had some good results lining my TL's with fiber acoustic ceiling
tiles. They don't absorb much at low frequencies, but they
do a decent job of deadening the higher ones, and still leave
lots of space for dacron or whatever.

Rick Shultz uses that stuff too... i will often use thick, dense wool-felt (salvaged from old speakers) to line the walls before stuffing -- in the BD-Pipes this consitutes most of the damping.

dave

 

[planet10]

My current enclosure for the FE167E is 40"x8.5"x8.5", the driver 11.5 down from the top and a 3"x4" port 4.5" up from the bottom. I'll update my web page someday.

I've heard a design based on the drawing on bob's page and it is a very good speaker.

dave

 

[GRollins]

Carpet scraps make dandy liners for transmission lines.

Grey