Accuton C173-6-090 versions

[igy137]

Hi All,

I recently ordered a new pair of C173-6-090 to replace my older set (one of the pairs started to make strange noises depending on how the screws are tightened on it). To my surprise, the new one is quite different from the older, despite the same model name.

From outside, the biggest difference is the magnet system. The new magnet is more rounded, and lacks the big magnet vent hole. Instead the new has 7 tiny-tiny holes on the back, but I'm not sure if they're really opened, actually. Moreover, the glue used for the anti-resonant cut-outs are also different, and the cone seems to have a very thin slightly shiny back-coating, too (I think that's not the case with the old one).

You can see the old version on the Madisound web page for example, the new one on the Accuton site.

Frequency responses and other graphs do seem also different, and I'm not exactly happy to see this going under the same type number.

Does anybody have some experience with those, can I just blindly drop-in replace the older ones, or should I adjust the crossover (I guess this is a yes, just would be nice to hear the opposite )?

Thanks,

igy

[Matt M]

Hi igy,

I can speak from the experiences replacing a C90-6-079 midrange. Similar story: the newer one has a slightly thinner frame and an added rubber gasket. Cutouts look different. Frequency response differs too: midrange is smoother and breakup is better controlled.
The newer driver IS an improvement. And I get reasonable good results with using the same crossover for both drivers. At least in case of the -079 I appreciate Accutons move to modify the driver.

As much as the changes are disconcerting, it really depends what the actual difference in frequency response and impedance is. Without seeing your actual measurements (gated SPL / nearfield SPL / impedance), it is hard to be more specific.

- Matt

[bvbellomo]

Similar experience with my C173-6-096E, although I never had an old one. Bought 2 drivers, one had a cracked cone, so I contacted them about a replacement - which they did send me free of all charges, but I also brought up that the other driver measured way different from their published spec. Here is there reply:

Regarding the difference between our data and your measurements we’ve been alarmed and made new measurements to find the status of our drivers. And we found that materials from our suppliers changed. The actual data we will issue in our new site which is headed to be published this month

And they did update their website. These drivers are so different, they can't really even be used for the same purpose! The specs for the drivers I ordered were suitable for a sealed 2-way, which these are not (their website gives 175Hz for -3db critically damped). I decided to keep the drivers (not sure if I could have sent them back or not) and went ported, which worked okay to 80Hz. I realize different people have different preferences, but at this price point, they really only make sense for the middle of a 3-way, which is how I intend to use them in the future. If you tried to use 1 of the old drivers for a left speaker and a new driver for a right speaker, you'd be completely screwed.

If the drivers mount the same, I'd call Accuton and complain and try to get them to send you a free or discounted 2nd woofer to match your new one. Otherwise, I would try to get your money back. The SB's new ceramic line looks interesting, measures well, a lot cheaper, and I wonder how well it compares.

[sdl2112]

Well that explains a few things, I bought the first new version from Madisound and my results didn’t match previous results. Thanks for the info.

http://www.htguide.com/forum/showthread.php?42901-Introducing-the-SSA-WG&p=606416&viewfull=1#post606416

[igy137]

Thanks for all the answers guys.
I finally had some time to do measurements comparing the old and the new.
Here's a screenshot of their far field responses measured.
Actually, the new does not look bad at all, seems even slightly better to me.
I decided to just drop-in while I'll have some more time adjusting the crossover.

[Matt M]

This looks pretty fine IMO. If your system is using a passive crossover, the 800Hz dip was never managed in the first place => so the new version is better.
At 3kHz you get an additional +1 dB. That might be worth looking into, if you want to have the fun.
But basically, I think you will be fine using these drivers as it is.

[sdl2112]

Thanks for all the answers guys.
I finally had some time to do measurements comparing the old and the new.
Here's a screenshot of their far field responses measured.
Actually, the new does not look bad at all, seems even slightly better to me.
I decided to just drop-in while I'll have some more time adjusting the crossover.

Thanks for posting igy....it looks like you may have the old and new swapped. The new one has the dip around 1khz and the double peaks in the higher frequency. Very similar to what I measured.

[igy137]

I hope not, here're the two curves separately.

Old:


New:


The double-peak is definitely gone with the new one. I checked my measurements for the older model from two years ago, there the 900Hz dip is not that 'pronounced', so this could be a measurement artifact too, but we're talking about 0.5 to 1dB if I read the scale correctly, so nothing serious here. Anyway, the breakup seems to behave nicer in the new model. (I've not measured the 2nd new one).

[sdl2112]

That is strange. From Accuton's new website the graph looks like this.


The old one looks like this.


Hard to explain unless they have more variations then we know.

Mine of the new type looks like this on a 11.7" wide baffle.

[bigwheel]

Hi Igy,

Unfortunately my older C173-6-090 broke 3 days ago and I started my search for a replacement. I am now looking for 1 second hand older unit (the one with the big hole!). Do you still have the old one lying around? If so, I would be interested.

Best regards, Laurens