Tech evaluation of the Iron Driver Loudspeakers

[r-carpenter]

Re: Tech evaluation of the Iron Driver Loudspeakers

This speaker sports the flattest frequency response of all contenders. Smooth falling off axis response and amp friendly impedance.

[r-carpenter]

Re: Tech evaluation of the Iron Driver Loudspeakers

Excellent work over all. Low linear and non linear distortions.
My only issue with this system and a subjective issue at that, was laid-back mid-range. Saxophone is an aggressive and vibrant instrument and on Ron's MTM it sounded very polite. I am guessing it's the sonic character of a smaller ring radiator. I would also try to flatten and extend port output by changing it's size but that's me and room I like.
CSD show well addresses internal standing waves. Over all, lots of attention to every detail. Meticulous design.

[r-carpenter]

Re: Tech evaluation of the Iron Driver Loudspeakers

this is it for now. more will be posted later on today.
now comments can be made

[ryanbouma]

Re: Tech evaluation of the Iron Driver Loudspeakers

Awesome design RonE.

[Ron_E]

Re: Tech evaluation of the Iron Driver Loudspeakers

Thanks for all the work you put into these measurements. I'm glad to see the C-Notes measured as well as I hoped they would. I'm relatively new to passive crossover design and the only thing that saves me is a technical background and good software. This is the first ported design I've ever done and has been a great learning experience.



Ron

[johnnyrichards]

Re: Tech evaluation of the Iron Driver Loudspeakers

Personally, I am glad to see it isn't just my samples of the Vifa ring radiators to show a rising 2nd order in the top end.

[Wolf]

Re: Tech evaluation of the Iron Driver Loudspeakers

Attaboy, Peepaj!!!
Wolf

[Wolf]

Re: Tech evaluation of the Iron Driver Loudspeakers

Nice as usual, Ron!
Wolf

[mzisserson]

Re: Tech evaluation of the Iron Driver Loudspeakers

Attaboy, Peepaj!!!
Wolf

One of my favs of the day, actually.

[ryanbouma]

Re: Tech evaluation of the Iron Driver Loudspeakers

Will we be shown detailed ratings by the listeners? It would be interesting to see how people rated their own speakers. Like if monoiz15 really ranked our speaker low, that would be funny. And also to see how they were rated. For instance, if someone wanted a speaker with great bass and refused to run subs, perhaps the winner isn't the best speaker. Or if they wanted great imaging, then speaker X might be best. Etc. That and it would be interesting to see.

[donradick]

Re: Tech evaluation of the Iron Driver Loudspeakers

Roman, thanks for the writeup. I think it's a very nice bonus to the designers to have a complete set of measurements along with an
expert analysis.

As usual I have some questions.

I recognize the linear distortion measurement with ARTA, but what package did the other distortion measurements?
What makes them a measurement of non-linear vs linear distortion?

You mention energy storage problems in several systems.
Is that shown by the CSD vs frequency graph or the other CSD.
Does this reveal only internal box resonances (inadequate filling or wall lining) or can it also show inadequte bracing?

regards,

[r-carpenter]

Re: Tech evaluation of the Iron Driver Loudspeakers

Will we be shown detailed ratings by the listeners? It would be interesting to see how people rated their own speakers. Like if monoiz15 really ranked our speaker low, that would be funny. And also to see how they were rated. For instance, if someone wanted a speaker with great bass and refused to run subs, perhaps the winner isn't the best speaker. Or if they wanted great imaging, then speaker X might be best. Etc. That and it would be interesting to see.

I think it's a good idea but not sure if Mike keeps individual scoring or it was discarded after data was imputed in spreadsheets by Mike and J.
But regardless, the winner is the winner based on over all scores. The budget and conditions of the listening set a framework for design and conceptual decisions.
Also, neither me nor Mike were judging loudspeakers. We were just mules. ;) We new what was playing at the time. Speakers, aside from last two entries were chosen randomly.

[r-carpenter]

Re: Tech evaluation of the Iron Driver Loudspeakers

Roman, thanks for the writeup. I think it's a very nice bonus to the designers to have a complete set of measurements along with an
expert analysis.

As usual I have some questions.

I recognize the linear distortion measurement with ARTA, but what package did the other distortion measurements?
What makes them a measurement of non-linear vs linear distortion?

You mention energy storage problems in several systems.
Is that shown by the CSD vs frequency graph or the other CSD.
Does this reveal only internal box resonances (inadequate filling or wall lining) or can it also show inadequte bracing?

regards,

Hi Don. You are very welcome.
Second package was "Sound Easy". I've positioned mic closer to one driver or another in order to get cleaner distortion reading in the range I was interested.
Linear distortions is aberrations in frequency response of a loudspeaker. There's no VS of linear and non linear. They are just aspects of loudspeaker performance.
Energy storage I mentioned, shows up as a long ridges on the CSD. It means that there's a standing wave present. It is often caused by the not enough if any padding on the walls and the amount of stuffing. In extreme cases it will also show as a distortion spike.
Unbraced panels resonances will show up as the impedance spikes . It means that the panel resonates itself and becomes somewhat a transducer on it's own. I have only seen it in a larger sub woofer oriented commercial enclosures that were made, let's say on the cheap side. The magnitude of the low F output of the iron driver systems and the sizes pretty much prevented this issue by default. Also, the usual approach of DIYers to overbuild anything, made a difference.

[Brewski]

Re: Tech evaluation of the Iron Driver Loudspeakers

I think it's a good idea but not sure if Mike keeps individual scoring or it was discarded after data was imputed in spreadsheets by Mike and J.
But regardless, the winner is the winner based on over all scores. The budget and conditions of the listening set a framework for design and conceptual decisions.

The numeric data still exists in the spreadsheet so it'll eventually be posted up or sent out to competitors Mike's choice there. In the sheet the criteria used for scoring are averaged so besides being a useful way for us to get the scoring done quickly it'll hopefully be semi useful for providing the designers feedback.

Take it easy
Jay

Will we be shown detailed ratings by the listeners? It would be interesting to see how people rated their own speakers. Like if monoiz15 really ranked our speaker low, that would be funny. And also to see how they were rated. For instance, if someone wanted a speaker with great bass and refused to run subs, perhaps the winner isn't the best speaker. Or if they wanted great imaging, then speaker X might be best. Etc. That and it would be interesting to see.

Just a PS the reviewers sheet is anonymous so you'll not be able to tie a set of results to a specific reviewer. Each speaker has it's own sheet in excel so if the results were treated like mwaf you'd only get to see your specific detailed results and then have the option of sharing them. I'm not sure how the result data will be handled.

[Pete Basel]

Re: Tech evaluation of the Iron Driver Loudspeakers

Nice work Ron, very nice! It looks from the dip in the woofer output as if the system is tuned
to about 28 Hz, and if you check the total summed output the response is very far down, about
20 dB relative to 1K. The system being so far down will not have much useful output there.
I suggest that you bring the port tuning up to about 35 to 40 Hz and you should
see a significant improvement in output. The cone excursion should be low at the tuning freq
but it is high at about 1.4 times it, tuning higher will provide better excursion limited output
at both the tuning frequency and above. Still, a very nice design, looks professional also!