Hi -- I just finished building a pair of pensil cabs with Markaudio 11MS drivers to go with the ACA I recently built. I took them for a test run. They sound amazing. The only problem is when I walk on the floor near them, especially when walking hard, they "skip," meaning that the vibrations from from my feet are enough to make the cones move further in an out then they are supposed to, causing them to misfire and making the sound go off. I have wood floors and no isolation pads or spikes on the cabs yet. I tried some foam isolation pads but they don't help. I'm considering adding spikes, if you think they will help. My kids and I like to put on a records and dance around the living room, which just won't be possible with these speakers unless I can find a solution. My previous speakers were bookshelf speakers on stands, but these cabs are way too big for stands in my small living room. Any thoughts beyond adding spikes? Is it because these drivers don't have a traditional spider, so move in and out more easily?
Thanks for your thoughts and advice! Now back to listening to some records (but not dancing to them). 🙂
Thanks for your thoughts and advice! Now back to listening to some records (but not dancing to them). 🙂
They're not skipping. They're moving out further than they should which sound similar to the TT skipping. 100% sure it's not the TT. I can see the cones of the driver doing this.
Use something other than a TT as source. The symptoms you describe are very much what is expected when the TT is disturbed.
With the high Rout of the ACA you may need a bit more damping than usual.
What speaker wire?
dave
With the high Rout of the ACA you may need a bit more damping than usual.
What speaker wire?
dave
If you hang the TT from the ceiling and it doesn’t happen it is the TT (of just use the tuner or CD).
dave
dave
That's a classic case of mechanical feedback. The more you dance around, the more the floor bounces up and down, transmitting this movement to the turntable, which in turn reproduces this low frequency oscillation to the speakers.
jeff
I had to add a flying buttress to the outside of the wall my TT hangs on to inimize the issue.
dave
dave
The many Joys Of Vinyl ... keep asking myself, do I really want to re-visit that audio era of my youth?
^Pretty much. I may have 30 LPs in mint playable condition, some of which are still in the wrapper recent purchases when at concerts, and another 30 who knows what's.
That must be it. The needle isn't skipping in the groove but the rumble is being transferred through the TT to the speakers! They cones don't move if I just jump up and down in front of the speakers when they're not on. I'll test w/ my CD player and report back. I even have a pre-amp designed to cut down on rumble but these speakers are obviously much more sensitive than my previous ones. If it's turntable rumble, what do you recommend? Will isolation pads under my TT's feet work?
The best way to avoid that kind of rumble is a sandbox: The TNT SandBlaster 1.0 That is the way i do it with my tunrtable.
An easier way is using a piece of strong foam or rubber sandwisched between two heavy stone tiles, it's a combo of damping and weight that eliminate those vibrations in any way. This is used by a lot of clubs in my area to avoid that the subwoofer affects the vinyl trough the floor, and that the dj stage interact with the turntable. Mostly they use 2 to 5cm thick granite or basalt plates for this and a plate of EPS floor isolation (which is also often used for acoustic isolating to the floor below in big buildings).
An easier way is using a piece of strong foam or rubber sandwisched between two heavy stone tiles, it's a combo of damping and weight that eliminate those vibrations in any way. This is used by a lot of clubs in my area to avoid that the subwoofer affects the vinyl trough the floor, and that the dj stage interact with the turntable. Mostly they use 2 to 5cm thick granite or basalt plates for this and a plate of EPS floor isolation (which is also often used for acoustic isolating to the floor below in big buildings).
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Yup. TT rumble was the problem. I had some felt pads that I used under my previous TT -- two square stacks of medium thick, rubber backed carpet pad cut to size. When I put those under the feet, it stopped the problem. Thanks all! Now I can listen and jump up and down if I want to! 😀
Any loudspeaker with a hole in th e box will unload below its tuning frequency. Rumble is invariably below that in frequency and the woofer becomes uncontrolled.
dave
I have solved the problem by hanging the TT from the ceiling. Good as long as you don’t bump it.
dave