Well I just dont know!

8675309

Member
2007-06-24 9:41 pm
Background. I am a 20 year bassbox and xover pro user.

I have recently been working on a design that will fit my current modified expensive 100lb cabinets.

My original thought was to use a satori 5 and Morel ST728 2 way with 4 SB acoustic poly 5's for low end. The satori has it's own sealed chamber and the SB's have a bass reflex chamber. My thought was do a 2 way on the satori and 728 passive 2 way with the SB's running active low passed for a little more low end. So 3.5k (modeled) on the satori and 728 and 150 between the satori and SB's using onkyo highpass on the satori 728 passive and separate amp low pass on the SB's. With appropriate impedance filters and plenty of measuring to dial them in.

So basically a 3 way.

So where it gets confusing for me. Spoke to the sales house that starts with an M and they thought it should work. Called back for advice before the order of drivers and got the engineer. He beet my horse to a point I am not sure my horse or years of experience will make this work.

So I am now looking at 3 options.. Go with my original design of hybrid active passive 3 way with lots of work

or

ST728 and Scan Speak 18W4531G00 2way

or

ST728 and Morel TCSW 634 2 way.

I am 100% confident in my enclosure design for any of the 3. I am confident I can make the 2 ways work perfect. I am not so sure on the multi driver satori and SB setup even though they look good in a model environment.


Thoughts

I will be happy to post more on my multi driver design.
 

AllenB

Moderator
Paid Member
2008-10-18 11:31 am
He beet my horse to a point I am not sure my horse or years of experience will make this work.
A sound reproduction system can't be truly perfect, but what isn't perfect isn't necessarily a problem. The compromises can get quite complex and dependent on each other. An engineer might see a plethora of issues along with solutions, so not necessarily a problem..but to someone else this might look like an impossible situation.

I'd try to keep it simple. Make sure the drivers can be overlapped. Don't run the cone drivers into their breakup region and look at how others have used them. Don't make the cabinets ridiculously narrow and round the edges if you can. It's all a learning experience.
 

eriksquires

Member
2013-05-10 4:11 pm
I'm completely confused. Too many part contractions. Can you list out your choices, including your 3 way, with links to the Madisound pages? You can say Madisound here, it's OK. :)

Something like:

- 1 Tweeter type (link here)
- 5 midranges in line array of type Morel 12345

Above your typing area you'll see icons. One has a world with a chain. That is the link icon. Highlight your text and then click that link icon. Cut/paste a URL to the parts you are talking about. :)


Best,


Erik
 

Lojzek

Member
2012-02-10 12:12 pm
Croatia

I suggest if you're gonna pay for the ST728 over $200/piece,
then it better have a replacement voice coil available as well.
I can't see any on Madisound or PE. Don't you find interesting
that other Morel tweeters in the range of $ 70-250 have exactly
the same voice coil assembly. ;)

edit: Have you tried to simulate bass extension of both of the
variants ( 4 SB's vs. single SS/Morel)?
 
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8675309

Member
2007-06-24 9:41 pm
I did model the drivers. The SS and Morel both go a bit lower however I have dedicated subs that can handle the low end. The SB setup has a bit higher sensitivity and a bit more cone area than just the single SS or Morel.

Having an extra set of voice coils for the ST728's. I already have the 728's. The only reason I got them is because they are matched drivers and I have always been a fan of Morel tweeters. However that being said should I be looking at something else?

The Transition between the Satori, SS, or Morel all have good transition. The Satori and Morel are able to crossover a bit higher than the SS however to keep the off axis response decent I will stay in a lower region. Unlike my competition cars where I ran mids as high as they would work.

And last it was mentioned not to make the cabinets narrow and to round over the edges. From all the information I have reviewed it was mentioned that less edge on the enclosure could assist with diffraction? Am I missing that concept?

At this point I don’t mind rebuilding cabinets because I do have a bit of extra space. Was just trying to get away with updated cabinets from a previous build that has a lot of money tied up in Russian Birch, MDF, and hours to build.
 

AllenB

Moderator
Paid Member
2008-10-18 11:31 am
And last it was mentioned not to make the cabinets narrow and to round over the edges. From all the information I have reviewed it was mentioned that less edge on the enclosure could assist with diffraction? Am I missing that concept?
By 'less edge' do you mean a closer edge?

There is not much point in declaring one cabinet size to be correct, none will be, and this has been discussed for sharp edged cabinets without a clear outcome. It is just my preference to use wider cabinets and I only suggested it to avoid anything extreme.

There are two broad concerns for a given cabinet size and one, diffraction especially in the kHz region can be reduced by rounding the cabinet. This results in what I would call 'less edge'. The other is the frequency where the baffle disappears and dispersion changes, aka the baffle step.
 

8675309

Member
2007-06-24 9:41 pm
So the only legitimate way to truly avoid diffraction is to router out cookies with the outer edges you need and glue and stack those cookies to build your enclosure. I have been considering this approach however my time restraints have been holding me back.

Basically this in a way.

[IMGDEAD]http://www.stereomojo.com/AcousticPreferenceGraciosoSpeakers.htm/images/AP-ZVOCNIKI068.jpg[/IMGDEAD]


From my reading, anything less than a 2" diameter rounding of the edge will not reduce that "edge", or diffraction "spray".
 

8675309

Member
2007-06-24 9:41 pm
I should add that I am considering the 2 way as I think this is something I can work with and possibly achieve good results without all of the work compared to multi driver setup.

The question would be which driver the morel or Scan Speak? The Morel drivers are close to $400 more per set however they look really good modeled and specs.

The SS are proven performers.

@ $397 Each
TSCM 634 - Morel

@ $211 Each
http://www.scan-speak.dk/datasheet/pdf/18w-4531g00.pdf
 

AllenB

Moderator
Paid Member
2008-10-18 11:31 am
So the only legitimate way to truly avoid diffraction is to router out cookies with the outer edges you need and glue and stack those cookies to build your enclosure.
It really is more involved than that, but your example is good for a box like that. You could always do something simple like cut up the cardboard core from a carpet roll or use quad cut timber to get there.
 

wintermute

Administrator
Paid Member
2003-08-03 11:43 am
Sydney
From my reading, anything less than a 2" diameter rounding of the edge will not reduce that "edge", or diffraction "spray".

I'd contest that :) even a 1" bevel has some effect, it won't eliminate the diffraction but it will smooth it out somewhat... I learned the hard way though, that it can make things worse (I did a 1" bevel all round, I would not do the bottom edge if doing it again).

Tony.
 

8675309

Member
2007-06-24 9:41 pm
It seems that the morel may have a wave guide built in?

[IMGDEAD]http://speakeraddict.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/m/o/morel-st-728-supreme-1-18-soft-dome-tweeter-pair-1.jpg[/IMGDEAD]
 
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AllenB

Moderator
Paid Member
2008-10-18 11:31 am
I'd contest that :) even a 1" bevel has some effect,
1" is a quarter wavelength at 3k4 after all, this stands to reason.
It seems that the morel may have a wave guide built in?
Interesting device. If a wild guess is in order I'd suggest this tries to dispense with the issue close to the dome so it comes under the precedence effect. By my humble opinion it doesn't qualify as a waveguide as such, but might achieve a similar quality. What do others say about this unit?