416-8B question

[Russnohio]

I just noticed something I've never noticed before. When playing music at very low volume levels ....volume at about 8 o'clock position...CD player NOT a turntable...I can actually see cone movement in my 416-8B woofers. (Model 19).Not just tiny vibrations either, sometimes they'll "bounce" at least half an inch! I've never noticed this before simply because I'm not normally in the habit of staring at my woofers while playing music. Now of course, at LOUD & moderate levels cone movement is a given especially with lots of bass....but at low "talk-while-the music-plays levels? Amp power source is a sansui G9000, and yes BTW...with the loudness button ON at very low volume but still....I tried the same EXACT process with my JBL 4312 speakers and visable cone movement is barely noticeable at all until I turn them up.


Normal for a 416-8B? Is this happening because they are very sensitive speakers? FWIW the sound is just fine.

Just curious and thank you!
Russ

[LICORNE]

Yes it's normal thats how they operate. Probably what gives them all that detail definition and efficiency.

By uing the loudness function you incrrease 17 DB
at 70 HZ also.

So don't be surprise and enjoy them . Altecs are the best.


..........

[Tom Brennan]

Hmmm, I don't see the woofers on my 19s move unless it's really loud and low; you know explosions in movies and junk like that. I bet it's the boost from the loudness.

[Ronald Lee]

Originally posted by Tom Brennan:
Hmmm, I don't see the woofers on my 19s move unless it's really loud and low; you know explosions in movies and junk like that. I bet it's the boost from the loudness.

<font size="2" face="Verdana, Helvetica, sans-serif">I would agree with you on the boost in the mid-bass due to the loudness button.

[scott fitlin]

Yup, the loudness cotrol is boosting low frequencies, and the 416 is a high compliance suspension, and this is whats making them move like you describe.

[Russnohio]

Thanks for the replies guys, Appreciate hearing confirmation that nothing is wrong. I won't worry about it then....not that I really was in the first place, but I just found it odd because my other speaker woofers don't move as much at the same given level.

Russ

[gamalot]

I will get back to you on this Russ.
Since we have about the same set up, G 9000 and 19s I should be able to reproduce the same actions.
I don't spend alot of time watching the woofers with grills off either so will make some observations.
I don't know what visible characteristics might be seen if the alnicos have lost some of their charge but I did have a pair of 19s that after many years began to display an annoying trait of what I called doubeling at high volumes. Woofer tended to get lost and just rumbled. I was never sure if this was from the lack of magnetic power or the lack of power from the amp.
I sold the speakers long before I ever became involved here or had any clue as to what the cause may have been.

Gary

[bfish]

416-8B Xmax = 0.15" (0.3" peak-to-peak), max excursion before damage = 0.7" peak-to-peak. Leaky, poorly-sealed boxes can cause over-excursion, and I understand M19s only construction seal is mechanical fit.

[sburke]

A few things you might look at that I haven't yet seen mentioned:

- Subsonic oscillations being caused by a mismatch of your tonearm/cartridge combination. For example, if you have a high compliance cart mounted on a high mass tonearm, the resonance frequency could be too low.

- Subsonic oscillations being caused by your amplifier. Could be anything from a feedback loop gone bad to a bad capacitor or resistor that would cause the filtering of that particular part of the circuit to be off.

- Inadequate isolation between your TT and its platform causing acoustic feedback.

- Record warps

If none of the above is true in your case, many folks get past this problem by using a subsonic filter to limit the ultra low frequencies.

[sburke]

Forget the parts about the TT. I just noticed you're having the problem with cd's not your TT. Duh!

You may still look at acoustic coupling between your cd player and what it is sitting on as well as how close it is to your speakers.