Super 8 questions

[badman]

I was hoping for some more detail on the Super 8. Dimensional drawings would be extremely helpful, as would a frequency response.

More than those, however, I would love to see a validation of the .157mH Le spec, which is extremely low, particularly for a driver of this type. If it's verifiable, then these jump up on the desirability scale by about 6 notches.

Thanks!

[woody]

Badman, I have an cheap and I do mean cheap meter that typicaly is off about 20%
using that meter I get .289 mh then using the CHEAP woffer tester from PartsExpress
I get .45mh so that .157mh may be a little low. One strange thing about that driver
is it has a rather wide bandwith. It's been a long time since I measured it but I think I
rember it going to above 10K but having said that it does have a rather nasty peak
about 2k but in subwoffer use that shouldn't be a major concern. Let me say again
my measurements may be off a country mile....

Why does the low Le make it more desirable to you?

[badman]

Low Le tends to mean a few things with respect to motors. 1 is that the Le(x) typically will be much flatter with a very low Le. This is source of distortion, though more high-frequency oriented. It also tends to be an indicator of certain characteristics in motors, mostly desirable. In this case, it may only be that there's a lot of clearance in the gap, to allow a little rocking during extreme (approaching Xlim) situations, though there is a chance, given the (impression of) build quality, that there's some shorting in the motor. It's likely a single-layer coil, too, and in whatever case, the steel seems like it'll be saturated under all conditions, which is obviously desirable.

[Apex Jr]

If you go back to the website and click on the picture there are
some more pictures and information listed about this driver.

Also check this out;
http://www.youtube.com/watch?v=P-fTjTcNQRM

3-17th-2011 found another link
http://www.youtube.com/watch?v=XXif_q5YkLs

Steve

[Shaun]

Originally Posted by Apex Jr

If you go back to the website and click on the
Also check this out;
http://www.youtube.com/watch?v=P-fTjTcNQRM

Wow! I didn't know a Super8 could do that!

Originally Posted by woody

One strange thing about that driver
is it has a rather wide bandwith. It's been a long time since I measured it but I think I rember it going to above 10K but having said that it does have a rather nasty peak about 2k but in subwoffer use that shouldn't be a major concern. Let me say again my measurements may be off a country mile....

It's been a few years, but I built an active sub using the Super8 and the full-range amp from ApexJr. The driver seems to be a true sub, in that it did not have much usable upper frequency extension. My experience is different to yours.

[form109]

i Disected one of the Two Super 8's i bought...the Woofer is a Monster and the build quality is excelent....the Voice Coil was a 2 Layer 2" Coil on a Kapton Former...the Pole Piece was Extended,i dont have any means of Measuring to gather real numbers...but the Super 8 does play well into the midrange...however it is not particulary clean,and by ear it sounds a bit Peaky,and nasal...the bass extension is it's strong suite...despite the rather Stiff Suspension and Highish FS (Posted around 47 Hz) the Super 8 Plays Deep,and even subsonic notes Easily...(that Large Magnet must make a Very Strong Motor)....being advertised as an 8" Sub the Large Surround on the Super 8" means the actual cone area is more like 6.5",not a big deal considering its low bass capibility.

[planet10]

I've been quite happy with my push-push Super8 woofer. I have measures but that doesn't include Lvc

dave

[Bluto]

Wish I'd have started this thread. I came within a nats hair of buying 4 of these a year back.

Couldn't find anyone who'd built them.

Got a deal from another member on some TB long throw 8's so went that route. Haven't decided what to build with them. Numbers are fairly close as I recall and was toying with Dave's design on the Apex Jr. site.

Sorry to hear opinion that the TB's aren't of same quality as the little Apex Jr.

As long as we're here; how about some comparisons by those experienced between Steves available amps with Dayton or OAudio.

[grubyhalo]

Originally Posted by planet10

I've been quite happy with my push-push Super8 woofer. I have measures but that doesn't include Lvc

dave

That's interesting. I'm considering a pair of Fonkens and wondering if it would play nice with a push-pull Super 8 for bass-heavy music. Would appreciate your opinion...

[planet10]

Up till now i've only been using the Apex PP with the HT (& a variety of mains including the Fonken)

I've been thinking of hooking it up to the mains now that i have a stand alone plate amp. I'll let you know.

dave