Clarity on Seas Thor Kit

[troystg]

And a few pics of Reputes nude bottoms...

[ericmcclurg]

I'm building a fat thor. Almost complete with the fabrication and construction however when I put the front panel on I noticed that I made a huge mistake. My speaker cut outs are exactly 6" below where they should be. My question is: Will the new speaker locations cause a problem other than simply not being at listening level?
Oh, I'm using 1" MDF for the front panel and I'm out of 1" MDF. I used 1" all the way around because I didn't want to make the braces. The internal volume is the same as used in the 3/4" design.
Hope someone out there can help me.

[ericmcclurg]

Ah hah! Man I'm a genius. OK. To fix this all I do is cut 6" from the top of the panel and simple glue it to the bottom. Now my speakers aren't 6" too low.
Thanks everyone.

"Ideas may drift into other minds, but they do not drift my way.
I have to go and fetch them. I know no work manual or mental to equal the
appalling heart-breaking anguish of fetching an idea from nowhere."

[planet10]

Originally Posted by ericmcclurg

Oh, I'm using 1" MDF for the front panel and I'm out of 1" MDF. I used 1" all the way around because I didn't want to make the braces.

The braces are still needed... thicker material does nothing to brace the drivers to the back of the box.

dave

[Mutuano]

Greetings!
Sorry if I’m posting at the wrong place but I would like to say thanks to Scottmoose, Planet10 and Martin J King for the excelent work done with the Small, Short and Fat Thor project.
Recently I’ve made a clone of the Small Thor speakers, using the same cabinet except for the drivers. I’m using 2 mids from Akronaudiotec (Akron KB6 - AKRONAUDIOTEC - Accesories and DIY - Mid Bass Akron KB6) and a Hiquphon OW4 tweeter.
The idea came up when I was playing with Martin’s worksheets and noticed that these drivers performed very similar to the SEAS Excel at the Small Thor cabinet.
Here some photos during the DIY Fest Rio:




Outstanding performance!!!
Regards,
Mutuano

[jackinnj]

Mutuano -- finding less expensive but comparable drivers paves the way for even greater use of this schema. Congrats!

[Mutuano]

Absolutely!
Thank you, Jack!
Regards,
Mutuano

[planet10]

Originally Posted by jackinnj

Mutuano -- finding less expensive but comparable drivers paves the way for even greater use of this schema. Congrats!

Scott & i have also just done a commission for a VIFA P17 Thor-alike. Not road-tested yet thou.

dave

[Mutuano]

Hi Dave!
That is an interesting project for sure.
One thing that I’ve noticed in this clone is the tremendous low frequency output. I’m still amazed with how low and loud this loudspeaker can go!!!
So that’s keep me wondering what is going to happen when I fire this speakers in my small room (it’s a 10X10ft room)…
The speaker is now with the guy who designed the x-over.
Because of that I’m already simulating a new MTM using a 5” drive instead of the current 6,5”, the Scan-Speak 15W/8530K01.
The simulations are not finished yet and you will probably see them at Martin’s Yahoo Group for discussions.
Many thanks once again!
Regards,
Mutuano

[ichiban]

Just read an interesting review over at 6moons,

In the 1970s, Joseph D'Appolito created an acoustical array of two mid/woofers symmetrically arranged above and below the tweeter in a vertical alignment. The main purpose was to eliminate lobing errors in multi-way speakers. Increasing vertical directivity wasn't initially important. Under certain conditions where poor listening room acoustics normally ruined the sound, one soon observed improved imaging and sound quality with this alignment. After more critical investigations, certain problems became evident as well. A D'Appolito system sounded vertically unstable and vague with even the slightest movement in the listening position. Thought the D'Appolito array today still has its supporters, most manufacturers ignore its strengths due to its compromises. The main problems with the D'Appolito configuration are:

• Interference at the crossover frequency: In most cases the distance between the radiating surfaces of the mid/woofers is larger than the crossover frequency's wavelength. This causes strong interference while moving in the vertical axis. Once you add a tweeter into this mess, the result is an acoustically very unstable behavior in the vertical axis.

• Different kinds of waveform behavior between tweeter and mid/woofers: Personally I find the even bigger problem to be that in a traditional D'Appolito configuration, the tweeter operates as a spherical radiator whilst the two symmetrical midranges tend to generate cylinder waves at the crossover frequency. While a cylinder wave fades at 3dB over distance, this doubles with a spherical wave to 6dB. The result is output instability over listening distance. To correctly balance a D'Appolito system is pretty difficult. Even in the best case the result will be more or less unstable. Is there a way to get a D'Appolito array to work properly?

http://www.6moons.com/audioreviews/aurelia/aurelia_2.html