THOR (seas) built Mjølner version pros and cons

[Ante]

Hi

Im thinking on building a THOR kit using seas drivers. Ive been reading a bit on different forums and they all conclude that the orig design was rather bad. Ive tryed to design a cabinet that is in the area between Short THOR ans SMALL THOR. I call it MJØLNER But I do not know if its is worth building. So I hope some of you have some experience and can give me some pointers, good ore bad.

If there is any reason why I should not do this built now is a good time to let me know

Ill be happy fore all inputs.

More pictures and distances will be provided as required.


Ante

[JonMarsh]

well, I think a statement like that should be qualified- one thing I hear frequently is that there are a number of versions of the crossover, some clearly better than others at suppressing the high frequency breakup modes of the drivers. Of course, the same can be said for RS180 + RS28a MTM's, of which there are quite a few variants.

Have you done a T/S analysis of your proposed construction using a program like Unibox?

What materials are you planning on using for the cabinet? (just to say, I'd rather have an MTM with the RS180 built with LBL, than an MTM based on the Thor design built with MDF).

Then, too, which crossover, and what quality of parts?

And finally, what does your room and your source gear look like?

All of these are factors in how satisfied you're going to be with the end results, versus the money spent. (and what are you currently listening to- is this going to be a big upgrade, or more of a lateral move?)

[Ante]

HI and thanks for your reply
Yes I have understood that there are many varieties of XO out there. I think and hope I have found the latest variant of jimangie73 XO design. I hope this will work well.
Im using 18mm birch plywood fore the internal.(cheese, topp, botton and ribbs). 3X6mm birch plywood plus 5mm oak fore the curved sides. Solid wood used fore the baffle and back.
I have not yet tried the simulation, but have googled UNIBOX now and wil try it out, Thanks 
I'm just at the beginning of the build and have onely done Car audio before. Here I used Alpine and JL Audio. So this will be the first built for home use and a decent upgrade from a Yamaha system I have today.
When it comes to amp I'm not sure yet. Hope I get to try different settupp when I'm done with the speakers. Considering both tube and regular. Someone who has experience?
The room they are going to play in is not yet defined.. But its probably going in my photo studio which is about 50 square meters. (7,5m X 6,5m with a height of 2.3m.) The challenge in this room is that one corner, I have built an infinitywall. It is almost like the inside of a circle. Curved transitions in ceilings, walls and floors. I do not know how this affects the sound. But there are quite a bit odd acoustics in the room..
Alternatively, in the living room if I can convince my wife. The living room is relatively small and narrow, so I can see this is not the ideal placement.
There are a lot of iffs here but Ill have to make the best of it and I realise I need help from you all

thank you

Ante

[TEK]

In a 50m2 room a MTM construction might have some challenges when it comes to bass response.
Are you planning on having one or more subs in addition to the speakers? If not it might be that this is not the design to fit your requirements.
What do other thinks? Will a MTM setup give a decent bass output in 50m2 room?

[Ante]

Hi TEK

No Im not planning on subs in this setup. Hopefulle Im allowed to have the speakers in the livingroom. Ill messure it today. If I have to put them in the studio I thougt the curved corner would be my biggest Challenge. If the studio wil become the permanent place, size does not mather anymore I still hope Ill be Abel to convinse my wife to hav it in Our livingroom though.

[tktran]

Do you already have the parts for this project?

Eg. Drivers, crossover parts etc?

I have an MTM based on Jimangie LR4 1.9Khz crossover in a 2 cu foot vented speaker, tuned to
38Hz. I also have a measurement system to verify that it measures very close to Jim Mitchell's spec.
I would say it a good speaker, much more livable speake than the original
Thor. But that's not saying much, because the original Thor is terrible. I got my pair of Thors
at a giveaway price, because the original owner couldn't stand it. It was his first DIY speaker and probably his last, confiding in me what he bought after he sold it to me. lol.

However, if you are starting from scratch, I would say- don't bother.

The W18E isn't the first choice for a pure midrange, and as a mid-bass, it just doesn't do bass very well. Not in 1997, and certainly not by 2017 standards. The tweeter is no longer state of the art, and poor value.
Jim Mitchell and others have done a fine job trying to rescue this speaker.

But starting with a clean slate will yield much better results.

[Ante]

No I have not bougt any parts yet. I figured that I have to figure out if its Worth it before I start bying parts. (just got an offer on the kit from Dynabell today 1550$) But as you point out, its an old system, I alsow had my conserns regarding the age. on the other hand, its a well tested system and a lot of resech is done to Perfect this design. So my question is if its still wortf it compered to other kitts today. I appreciate alternative kits to consider

[Steve Manning]

My $.02 ...... back when I joined the forum I was considering building the Thor's as well. I had some dialog with Jon and he convinced me into building a pair of Modula MTM's. I was very pleased with the results and as I recall component cost was a fair bit less than doing the Thor's. The Nat P's have a modified crossover and tweeter to the Modula's if I recall correctly and you have the option of going stand mount or floor stander.

[wkhanna]

choosing the room (size) will have to be the first step.

another consideration may be where Ante, is located & what materials & drivers are readily available.

just off the top of my head (& to fulfill my own latent desires) my recommendation would be a "Duded-Up" set of 68 litre, curved sided, Natalie Portmans.

these would offer the precise detail, or as Ante stated, " open, clean and honest", along with substantial SPL, albeit possibly a bit anemic on bass if they were exiled to the larger studio room.

[wkhanna]

What is, in your opinion Bill, the best setup on the Nat Ps? Drivers, tweeter, volume and XO?

Hi, Ante.

i have lived with my 68 litre floor-standing Nat P's built with standard drivers & xo for over eight years now.
in that time i have also been going to many audio shows, high-end shops, & visiting my many friends with upper-mid & high-end systems.

my room is 14 feet x 19 feet.
i typically listen at around 70 to 75 dB.
all my music is either vinyl (over 600 lps), CD's ripped to lossless 44.1 or hi-res files.
resolution & accuracy are V important to me.
every time i hear a better system/speaker than mine, when i come home, i am still V happy with my Nat P's.
their ability to accurately reproduce real music & voices never disappoints me.

granted, there are many systems/speakers better than mine.
they may have better bass, imaging, or maybe the ability separate out individual instruments in a symphony orchestra, or not get quite as congested with massed instruments at higher listening levels.

still, anyone who has ever heard them always complements me on their clarity, smoothness, naturalness & realism.

i am currently in the process of a $1k upgrade with ScanSpeak tweeters & high-end xo components.
some might think it unwise to invest so much into an eight year old, somewhat nondescript looking speaker.

i can already say, with full confidence, this new investment will return many times over on its initial cost.

hope this helps to provide some answers to your questions.

[Renron]

that is a build anyone could classify as 'End Game'

Bill, I wholeheartedly agree with you. If I hadn't already built the Ardents, those would be next. Everyone who has built them enjoys them. Thor killers.
Ron

[Ante]

Poit taken. Im trying to set opp a New drawing With all the imputs that you all have given me. the base is the mix from deewan. Do the mid tunnels have to be scuere? It seems easyer to use cirkular pvc pipe like the one used in the Anthologys. Yes theyr open in the back now. Ive put the drivers as they were With the tweet about 960mm above the floor. the With of the baffel is 290mm and are dobbel layer viner. the toatl hight wil be around 1240mm. the Depth is 500mm. I thinking on using a 3" by 4" vent in the front below the botton woofer. The mid vent will bi slightly longer than the original, wil this be ok? I hope I can use the PVC pipe and I wil manage to fit the foam.

deewan: If you could give me the Hight, Depth, Baffel with and hight on Your tweet in the mix build I would be moust happy And if you dont mind me asking, are you still happy With Your statement II?

[wkhanna]

i will be more than happy to manage the thread modifications if it is ok with Ante.

[DFAL Minion]

utilizing teachings from my Master, ET, i have executed a DFAL Dark Force transformation on this original thread whose progress may be found HERE