Box variations on the MLTL for the Fostex FE167e

[loninappleton]

After a long time of using only cast hole cutters I had some success making a hole size over 5" with my simple tools and a better router bit. The process went pretty smoothly even on some rugged chipboard stuff.

So with my new found skill I feel better about moving up to one of the 6.5 in Fostex. Can someone give some measures for this?

I have been doing my research and scouted around for some of the
completed projects by Martin and Bob Brines.

This test box would emulate the succesful design by GM for the FE127e and shown at zilla speak.

The difference between what's available and what I would build
is that the port goes on the bottom. I find the arrangement of
MLTL on a small stand with port exposed and extended at the
bottom to be most satisfying.

Also I think that getting the width greater than the depth will give a larger and better front baffle without going to a suprabaffle doubling the hole depth.

One possibility would be driver off set of center to achieve the 'wing effect' that Jeff (Godzilla) was experimenting with.

Unfortunately I have not worked the Mathcad program by MJK.

[GM]

I prefer floor loading too.

Yeah, I'm pretty much a 'broken record' about wide baffles.

Right, you never want to place the driver dead center of a wide baffle.

Anyway, what 'measures' are you asking for?

GM

[loninappleton]

Originally posted by GM
I prefer floor loading too.

Yeah, I'm pretty much a 'broken record' about wide baffles.

Right, you never want to place the driver dead center of a wide baffle.

Anyway, what 'measures' are you asking for?

GM

Well whatever you come up with for the FE167e in MLTL. I did a search but the searches turned up other drivers and the Brines MLTL.

Other thing I noticed is that Bob's and Martins MLTL's have the driver
positioned higher than the design you made for the FE127e.

Right now I'm putting together a test box from scraps with my practice cut-out. Haven't ordered the speaker yet. And yes I'm still using one MLTL and one BIB asymmetrically.

The goal for me is to get driver and port tube terminus near ear height using the small stand system I've done with the FE127e:
bottom exiting port with tube extended through the top of the
stand/platform. There is no theory for this, just personal preference and making do with what comes to hand.

:-)


Speculating on this asymmetrical build style, if I had one FE167e MLTL, I could add a FF165 BIB build per Jeff's suggestion that the
165 is best in a BIB. But one thing at a time.

[Godzilla]

>>> I could add a FF165 BIB build per Jeff's suggestion that the
165 is best in a BIB.

I am not sure the 165k is best in a BIB. It's a great choice but there are others equally excellent.

If you were going to continue with your asymmetrical build style it would likely be best to use the same drivers. Interesting idea actually. I can imagine a BIB in one corner, a MLTL against the wall sitting near a sub...

[Bob Brines]

Originally posted by loninappleton

Other thing I noticed is that Bob's and Martins MLTL's have the driver
positioned higher than the design you made for the FE127e.

I usually design to minimize the third/fifth harmonic. In a straight MLTL, that means the driver is 25% down the pipe.

Bob

[loninappleton]

Hi Jeff,

The only subs I have are made with bread.

The BIB gives excellent low frequencies for my usage. We mentioned before how good those low piano notes ring from the BIB.

With this in mind, I always position the MLTL to the left and the BIB to the right as a piano would be positioned in the soundstage. So highs and mids left of center and bass notes right of center. I do all this listening and building alone so it may all be hooey.



The only subs I have ever heard is that junk sold with computers. It was not much of a musical experience. And that experience was extremely brief.


On the high end, I've wondered what the orchestra range is. I have wanted to complete another MLTL with a 5 inch Tangband which is not a full ranger. I'm dodging talking about that so the post doesn't get moved-- again. But in general TB's use more power than a high efficiency Fostex. That was my experience with the W3 871 anyway.

[loninappleton]

Originally posted by Bob Brines


I usually design to minimize the third/fifth harmonic. In a straight MLTL, that means the driver is 25% down the pipe.

Bob

I have not made much progress over time in design admittedly. But I still like the company here.


The Brines MLTL looks more like the Alpha TL only with a port.
I got the idea that positioning the driver -- I think it's 1/3 down --gave the fullness of sound I've come to appreciate with it. And that on a wider baffle with shallow depth.

Today I've begun whacking together a test box. I am getting the yen to buy something from Madisound-- too bad I can't just go down there and pick up an order.

[Godzilla]

>>> I am getting the yen to buy something from Madisound-- too bad I can't just go down there and pick up an order.

Yes, it makes it more difficult to hide what you've spent on drivers from the wife!

Yes, TB will be less efficient but that does not mean they sound any less good overall. Some even prefer their sound to Fostex.

As for subs... i knew a shockingly beautiful girl that used to work at a nearby Subway. If someone picked up my order she would call me on the phone to tell me she made my sandwich. She was Indian, trying to make money so she could continue going to school in the USA. Her friends coaxed her into entering a modeling competition and without any experience she went down the catwalk and took second place. Later that year her uncle in India found her a husband to marry. She went back to India and never was heard from again.

We complain about not being able to hear drivers before we buy... imagine not being able to meet your husband before you marry him? As far as i'm concerned, the guy got to marry a Feastrex! Imagine that showing up on your doorstep.

Enough about subs...

[GM]

Originally posted by loninappleton

Well whatever you come up with for the FE167e in MLTL.

Other thing I noticed is that Bob's and Martins MLTL's have the driver
positioned higher than the design you made for the FE127e.

Yes, I place the driver based on a length to CSA ratio to minimize anomalies in the driver's acoustic phase. Whether the differences between the two design paradigms is audible or at least subjectively different I can't say since I'm an 'if it ain't broke, don't fix it' type.

Anyway, the sim I initially published is somewhat larger for the same tuning than BB's AFAIK, so you may want to use his if it's available:

L = 56"
CSA = 85.168"^2
zdriver = 19.75"
dport = 4"
Lport = 1.5"

Recommend spacing the cab up between 1.25 - 3.375" if bottom vented, otherwise locate it near/at the bottom.

GM

[loninappleton]

Originally posted by GM


Yes, I place the driver based on a length to CSA ratio to minimize anomalies in the driver's acoustic phase. Whether the differences between the two design paradigms is audible or at least subjectively different I can't say since I'm an 'if it ain't broke, don't fix it' type.

Anyway, the sim I initially published is somewhat larger for the same tuning than BB's AFAIK, so you may want to use his if it's available:

L = 56"
CSA = 85.168"^2
zdriver = 19.75"
dport = 4"
Lport = 1.5"

Recommend spacing the cab up between 1.25 - 3.375" if bottom vented, otherwise locate it near/at the bottom.

GM

I seem to recall this one just a bit or something similar. Thanks for putting it in here.

I have renewed my acquaintanceship with Madisound and know that it will be about $75 ea. to order.

The test box I'm making is nearly finished. It is larger than that for the 127e but way smaller than a floor stander in the 56 in range.

When I go ahead with a more finished piece from what you've given, what is the suggestion for driver offset, if any?

This time I'll put your sim in a safe place and not lose it.



How is the housebuilding going?