Cabinet design for Morel MW168

[ckwong99]

Hi All,

Can anyone introduce a cabinet (with dimension) for my Morel MW168 + MDT30. I tends to have a rich bass reproduction.

Also how to design the crossover for this system. By two ways of approach 1) Woofer direct connect 2) Through a passive component.

Analogy

[Inductor]

ckwong99 hi,

You should be able to simulate your box dimensions with a software like WinISD or other. Did you test one before? Maybe some one can give you the best box size for that speaker that would save you some time but not the fun for doing it.

Now for the xover, with your Morels you should be fine with this one I designed for Etons. Lpad is joining in the same thread. You should need a -2dB Lpad but there are other values there like a -1,5 dB Tweeter Lpad. You will test for the best flat sound (output) or the way you like. (I can't remember if you need this anyway because, besides there are values there for all the Lpads, you may not need one afterall if the xover filter takes that into account in the first place.)
(Your woofer is 88dB and your tweeter is 90dB) That's why you will need about -2dB pad on the tweeter. Is this Ok?
Have fun.

http://www.diyaudio.com/forums/showt...905#post863905

Parts List:
Capacitors
C1 = 18 uF
C2 = 6.8 uF
Inductors
L1 = 0.91 mH
L2 = 0.35 mH
Resistors
R = n.a.
R1 = n.a.
R2 = n.a.

http://www.diyaudio.com/forums/attac...amp=1141756525

[sreten]

Originally posted by Inductor

(Your woofer is 88dB and your tweeter is 90dB)
That's why you will need about -2dB pad on the tweeter.
Is this Ok?

Hi,

Generally its not unless you like speakers with no baffle step compensation.
Hardly a "rich" alignment. BSC designed mid/treble level is around 84dB.

/sreten.

[Inductor]

Originally posted by sreten

Hi,

Generally its not unless you like speakers with no baffle step compensation.
Hardly a "rich" alignment. BSC designed mid/treble level is around 84dB.

/sreten.

Also it depends in the room you are, the position of the baffle in relation to the floor and on the internal resistance of L. (And on the size and position of woofer on the bafle). How much do you use on your bafflestep? 4dB's? (88-84). At what frequency output, <600Hz? This have little to do with the xover frequency of 2000Hz and up I guess. Or is it something else?

[ckwong99]

Thanks to your reply.

Actually, I tired to calculate the cabinet size but some parameter I can't understand. As a end user I would like my spk have smooth response between 50 to 20k Hz.

http://www.partsexpress.com/resources/pebox.html

Above is my calculation program obtained from partsexpress. It told me what dimension of cabinet but only input the part number. My woofer item number is (297-030) and the optimal size is 1.29 cu ft with 21 x 13 x 8 inches. Not sure this program accuracy and how to verify it ?

The x-over someone told me use 3-4k Hz. Due to this woofer is dual coil for mid-bass range type. How do you think ?

I will use the vented type cabinet because I tends to like a rich bass. In additional, my listening area around 9x10 feet so i intend to locate my spk close near the wall. therefore the air flow hole must be put at baffle (front side of the cabinet). I am not sure where to open the air hole at the baffle surface.

CK

[Inductor]

Morel MW168
http://www.partsexpress.com/pdf/297-030.pdf

Morel MDT30
http://www.partsexpress.com/pdf/277-015.pdf


ckwong99,
Hi, When you analyse this speakers they asked to be crossed at 2K or 2K5 and up. 3K or 4K is goood but not perfect unless you use another woofer. This tweeter Fs is at 700Hz (resonance) so that you want to go way from it (up) and with the right xover you will be fine (what is not the case w/ a 1. order xover). Second on the side of the woofer after 2k5 you start with transients on the frequency output what is telling you is to cross right there.

The duct position is not critical in the baffle.

One thing I dont't understand. You say it is a double voice coil "this woofer is dual coil" . Do you mean a double magnet?

This xover is a good start ( 2. order) but as with everything in life might need some adjustment. Notice the inverted tweeter because of 180º (90º+90º) inversion of phase in 2. order xovers.

Also how to design the crossover for this system. By two ways of approach 1) Woofer direct connect 2) Through a passive component.

To get to your point here, I am not sure a direct connect works with this type of woofer with a voice coil inductance of 0,62mH only. In this case you need a good passive xover. Unless you have an active xover and separeted amplis.
Have fun.

[ckwong99]

Sorry the woofer is double magnet design.



If I follow your x-over at 2K frequency connect to these two Morel units. So how should be the cabinet internal dimension when tunning frequency is 60 Hz ?

What the air flow duct diameter and length ?

Can anyone help me make this calculation. Thanks for your support in advance.

Hi Inductor , what the size of your cabinet and how much your Eton unit ? 5 or 7 inches ?

CK

[Inductor]

MW 168
recommended cabinet 1:
closed cabinet with 1,1 L volume
from 158/99 Hz (-3dB/-8dB)

recommended cabinet 2:
2,4 L volume bass reflex cabinet
with 65 cm long HP70 reflex tube
from 99/74 Hz (-3dB/-8dB).

(from the website: http://www.lautsprechershop.de/hifi/index_en.htm)

Hi Inductor , what the size of your cabinet and how much your Eton unit ? 5 or 7 inches ? ckwong99

Sorry, I don't have cabinets for Etons.

So how should be the cabinet internal dimension when tunning frequency is 60 Hz ? ckwong99

Sorry ckwong, right now I don't have the time (exams) to simulate in WinISD or other software. I din't check the recommended cabinets sizes, so I am not in a position to help you in that either.

To simulate in WinISD is a work I like to do and also very personal in the way that you can choose output and size of cabinet.

[sreten]

Hmmm........

The cabinets are even more inane than the crossover design.

/sreten.

[Inductor]

ckwong, do you work with metric or imperial?

(About) the port, are you looking for a size DxL that you like? (or that you have available?)

When you make the box enclosure() Make sure the internal volume is without speakers vol., port volume, baffle thickness etc.

I used this specs instead.
Morel MW168
http://www.morelhifi.com/products/raw_woofers.html

Morel MDT30S
http://www.morelhifi.com/products/raw_tweeters.html

note: please ckwong, don't get confused because of the use of different softwares, each one has it's own number crunching so that results can be a little different. here is WinISD.