Clarity on Seas Thor Kit

[Byrd]

"His results are incorrect." If you make a statement as absolute as this you are under obligation to prove it. If you had said "My belief is that his results are incorrect" you would then be entitled to your opinion

As to subjectivity - there are numerous reports indicating that bass is quite sufficient

[planet10]

Originally posted by Byrd
Again I ask you for proof that you know for a fact that the measurements provided by Joe d'Appolito are incorrect. Simply because Seas measured one speaker correctly does not mean that they did so with the Thor.

Come on... only Joe knows and we don't really care. We know you want to build these -- you may even have bought the bits -- and it must be unsettling to see the unresolved issues surrounding the Thor.

The drivers are outstanding (if you like the Danish school of drivers). Build the box & see.... you can always build a different box if needed.

personally, from ScottMoose sims, a bipole of close to 2x the volume of the Thor would be a safer bet (you wouldn't catch me buying those drivers thou -- even if i could afford them)

dave

[Byrd]

Planet - Until it is proven that Joe's results are incorrect a statement such as "His results are incorrect" without proof is non factual as it is an absolute statement.

I was under the impression that "Posting non factual information" was frowned upon by the moderators?

If read post #6 - My intention all along was to build 2 prototypes.

[catapult]

One last time and I'm done with this tar baby. Measuring in an anechoic chamber is always superior to trying to "fake it" with mathematics and in-room measurements. Bjorn Idland, the Seas tech in charge of measuring speakers and drivers, is quite competent and I trust his results over anybody's "quasi-anechoic" measurements. There is simply very little to go wrong if you have a chamber at your disposal. Joe does not have chamber and his results are therefore suspect. I won't venture a guess about where he went wrong but there are many places along the line where it could have happened. Turn the question around, other than stubbornness and blind faith in a "guru", why are you so sure the measurements in the article are right when all the evidence indicates otherwise?

You can lead a horse to water......

[Byrd]

This is still not proof. It is supposition based on your assumption that Bjorn is competant. This may well not be the case in this instance.

By "in -room" measurements - you are refering to CLIO of course.

I have not once stated that d'Appolito's measurements are accurate, nor has anybody else stated that his measurements are innacurate for that matter. They may have suggested it - but did not state it as fact.

"All the evidence" does not correlate. Joe's shows one version, MK's calcs show another and so does the Seas measurement. BTW the official response from Seas - who you trust - is "No attempt was made in that measurement to splice the port output with the woofer output". As the port is rear facing measurement of port output would have been severly diminished

[catapult]

As the port is rear facing measurement of port output would have been severly diminished

Oh, please. You're just displaying your ignorance now. Bass doesn't care which direction it is "pointed." I'm finding it hard to be polite so I'll just sign off. Enjoy your speakers.

[planet10]

Originally posted by Byrd
was under the impression that "Posting non factual information" was frowned upon by the moderators?

If the mods were to polic every instance of someone saying, "X is" instead of what they really meany, "it is my opinion, X is" we'd need 10x as many mods... you just have to read between the lines....

dave

[planet10]

Originally posted by Byrd
Until it is proven that Joe's results are incorrect a statement such as "His results are incorrect" without proof is non factual as it is an absolute statement.

No one is going to prove anything wrt this. Give catapult the benefit of the doubt. Joe's results are certainly suspect -- i was suspicious of them since i 1st read the article. Can't remember where but i've seen other Thor measures -- they are closer to SEAS results than Joe's.

On another point. The SEAS results -- and Joe's statement -- indicate that these have been stuffed to the point of being aperiodic. That means that response will be substantially similar to a sealed box of the same size (but with less time-smear from back re-radiation and a smaller impedance peak).

dave

[bidland]

Hello,

I got an e-mail from Ross Saunders about this ongoing discussion and I see my name has been mentioned earlier in this thread.

I think D'Appolito's work is well documented in his AudioXpress article and I hope you understand that I cannot answer on behalf of him as a designer of the Thor speaker.

I can confirm that the measurement of the Thor speaker found on our web page is done in a 4pi anechoic chamber.
http://www.seas.no/kit/thor.m%E5ling.pdf

Measurement conditions:
Our chamber have these inside dimensions: L: 960cm x W: 650cm x H: 755cm. All walls, floor and roof is covered with 1m long absorbents (leaving 5cm of air between the wall and the absorbents). The room weighs 200 tonnes and is decoupled from the ground with steel springs. We have an absorption factor higher than 0.99 down to 70Hz. We use a Bruel & Kjaer 4133 mic capsule and a Type 2606 mic amp.

I have attached a measurement of another Thor speaker that also shows the nearfield output of the woofer and port. The level of the nearfield measurements are offset from the 1meter anechoic response.

I have not done any correction of the port output level, as D'Appolito has done in his article.

Hope this helps, but if you need other measurements I'll try to find the time to do this.

Martin King's spreadsheet looks like a very good tool for calculationg TL's. Has anybody built a TL with the W18E001 using his spreadsheet?

Bjorn Idland
Lab tech.
Seas

[JDeV]

Originally posted by bidland
I can confirm that the measurement of the Thor speaker found on our web page is done in a 4pi anechoic chamber.
http://www.seas.no/kit/thor.m%E5ling.pdf


I have attached a measurement of another Thor speaker that also shows the nearfield output of the woofer and port. The level of the nearfield measurements are offset from the 1meter anechoic response.

Bjorn Idland
Lab tech.
Seas

Hi Bjorn,
Thanx for your assistance in this matter. Although I did not really participate in this discussions, I also completed a Thor about 5 days ago and am interrested in the outcome.

The attachement (of the other Thor ) you are talking about, is it the pdf on the Seas website, or are you still going to post it?

Thanx again.