Tech evaluation of the Iron Driver Loudspeakers

[r-carpenter]

This part will describe tech aspects of each loudspeaker presented and go in to details of the performance. I will also add my own comments which should be looked at just as so.
Over all, designs presented where done at a very high technical level. Concepts and decisions by each designer were fairly clear and justified. Where were no random choices in components or crossovers and the results are impressive to say the list. Only two systems presented potential issues for the amplifiers and we also played these systems last at the subjective evaluation (for the fear of blowing fuse on the amp).

Also, I am downsizing graphic files for posting but if anyone wants a full size set, pleas email me. Total graphic size of all loudspeakers is 240mb. all bitmaps


NONE of the Levels are absolute.

[r-carpenter]

Re: Tech evaluation of the Iron Driver Loudspeakers

Kenny K, Audio Noir.

This system had a potential short in the crossover (both speakers) causing impedance to be voltage dependance. In other words, over all impedance would drop to 1ohm at 2.83v applied and go back up to 3ohm or 4ohm at a lower voltage. We played this speaker system last for this reason. Mike was visibly sweating as well as his amp, on the loud passages.
Kenny, you need to inspect crossover schematic and find an issue.

[r-carpenter]

Re: Tech evaluation of the Iron Driver Loudspeakers

Continuing

[r-carpenter]

Re: Tech evaluation of the Iron Driver Loudspeakers

Over all a low distortion system. Some energy storage issues in the case (top to bottom) but nothing that cannot be remedied with padding.
Woofer response is designed flat without BSC compensation. Tweeter was a bit too hot and crossover transition between woofer and a tweeter wasn't worked out to perfection.
STI and RASTI are very good and off axis response is smooth falling. Excellent first try and with some adjustments this baby can play tunes like a chickadee.

[r-carpenter]

Re: Tech evaluation of the Iron Driver Loudspeakers

Second system that caused Mike to worry was ScottQ's. No problems in the impedance but rather a very inefficient loudspeaker. I could not play it very loud with my Carver 100wtpch amp but Mike's beast forced it to the set SPL level.

Over all a very complex 3-way system with modified woofers, semi-dipole firing mid-range and 3 short ports. Lots of thinking went in to this one and lots of good ideas. I also know that Scott had issues with his measurement gear and was very short on time.
I have taken a few extra measurements to see whats what and so here it is.

[r-carpenter]

Re: Tech evaluation of the Iron Driver Loudspeakers

Box was stuffed fairly tight. No pronounced ringing is present in the drivers or internal structure. Very heavy cabinets.

[r-carpenter]

Re: Tech evaluation of the Iron Driver Loudspeakers

I've looked in to side firing openings of the mid-range. The magnitude of the signal was very low in relation to the front firing SPL of the mid-range.

[r-carpenter]

Re: Tech evaluation of the Iron Driver Loudspeakers

Linear distortions of the system are fairly high but nonlinear are admirable. 5k noise is external and not the systems fault.
Over all, the system scored low and my guess for the reason behind, would be it's ragged frequency response. This speaker has a multitude of factors contributing to the performance and shows to be big challenge. Tough balancing act, especially on the budget.

[r-carpenter]

Re: Tech evaluation of the Iron Driver Loudspeakers

Jeff Sonney.
Another Ring Radiator marriage.
Nice system. May be a bit outgunned by other competitors sizes. Very smooth frequency response on and off axis. Top octave is a bit rolled off which I suspect affected the total score and made the speaker sound somewhat dark, compare to others. Energy storage issue but rather inaudible in the listening test. I was trying to spot the ringing during the program and couldn't. Smooth impedance with not much phase swing.

[r-carpenter]

Re: Tech evaluation of the Iron Driver Loudspeakers

continuing Jeff Sonney

[r-carpenter]

Re: Tech evaluation of the Iron Driver Loudspeakers

Over all, low linear and non linear distortions. Very well balanced with perhaps a tweeter choice as a weak point(my opinion only). Amp friendly impedance as well. Interestingly, behind the screen, the loudspeaker sounded much bigger then it's actual size. Me and Mike were going "wow!" silently...... One of the better looking speakers IMO as well.

[r-carpenter]

Re: Tech evaluation of the Iron Driver Loudspeakers

Biff + Boroson
Large MTM with felt surrounded ring radiator tweeter (and a handle on the back. Thanks!)

[r-carpenter]

Re: Tech evaluation of the Iron Driver Loudspeakers

continuing

[r-carpenter]

Re: Tech evaluation of the Iron Driver Loudspeakers

Over all.
Well build and stuffed/padded cabinet. Some good ideas implemented. Probably tightest and deepest bass among the rest of competitors.
Unsatisfactory (to my taste) tweeter/mid balance. Subjectively, system sounded very laid back and was missing a few details. Impedance dropping just a bit lower then 4ohms at the crossover but not much.

[r-carpenter]

Re: Tech evaluation of the Iron Driver Loudspeakers

RonE
Mid sized slim MTM with smaller ring radiator tweeter.
Clean casework, spotless finish.