Partially Blown??

mjock3 · « **on:** 14 Apr 2011, 05:53 pm »

I was wondering if I might have a partially blown speaker. It sounds OK at lower volume but when turn up it is distorted. Whereas the other speaker is still clear. Any help appreciated. Also if it is blown any idea where I can get the driver, it is a Sonus Faber Concerto.

Thanks in advance,

Mark

Pez · « **Reply #1 on:** 14 Apr 2011, 05:59 pm »

It is very possible the driver is blown. Is this something that has happened recently or has it been on going? Also tell us a little more about what you have in your system.

srb · « **Reply #2 on:** 14 Apr 2011, 06:12 pm »

I assume you have swapped the left and right speakers to make sure there is not a problem with one channel of the source or amplification (or even a speaker wire if only partial contact is being made)?

If you have determined that it is the speaker for sure, I would then determine whether it is the woofer or tweeter that is distorting and carefully remove the driver to check the connections to the driver terminals. If they are Faston-type push-on terminals, it's possible a loose terminal might cause the symptoms you describe, but more likely there could be a problem with the driver.

I'm not sure whether the Concerto used stock drivers or OEM modified drivers (usually Scanspeak or Seas), but drivers for older models may be hard to find.

At that point, I would contact the distributor, Sumiko, for information and assistance. http://www.sumikoaudio.net/idx_contact.htm

Steve

mjock3 · « **Reply #3 on:** 14 Apr 2011, 06:18 pm »

It has been going on for probably a month. Just today it seemed more obvious. The was some bass coming through very distorted. I have a Sonic Frontiers Integrated amp. About 50wpc. A Ah! 4000 cd player and a turntable setup. Which is what first showed me the distortion. I was setting up the cartridge with an isolator standing at the turntable and started playing a record and noticed distortion out of the right speaker. Checked the left and it sounded fine. So the my story and I'm sticking to it.

mjock3 · « **Reply #4 on:** 14 Apr 2011, 06:20 pm »

Have not switched the speaker wires. Thanks for the suggestion I will check that out.

mjock3 · « **Reply #5 on:** 14 Apr 2011, 07:09 pm »

O.K. I switched the speaker wires and still happening in the right speaker.

Pez · « **Reply #6 on:** 14 Apr 2011, 07:11 pm »

blown... Sorry.

richidoo · « **Reply #7 on:** 14 Apr 2011, 08:29 pm »

Check that the driver mounting screws are tight. Check the electrical connections throughout. Especially where wires connect to rear (internal) of speaker post and where they connect to the drivers. It is hard to blow a high end speaker because audiophiles usually don't ignore the bad sound of clipping. If there was no "incident" like bad pop or someone else partying with them then it could just be something loose or out of whack. Check that the reflex port is clear. Good luck

Pez · « **Reply #8 on:** 14 Apr 2011, 08:37 pm »

While Audiophiles may not push past distortion it is always possible that the speaker left the factory with some sort of defect that went undetected for a while then later got much worse. I had that happen to me where a speaker was never run hard, but had major distortion problems months after purchase.

mjock3 · « **Reply #9 on:** 14 Apr 2011, 08:41 pm »

I just did check driver connections and they are nice and tight. As for popping, I do get a popping when my frig turns on and off. Don't know why, I have a dedicated circuit for the stereo. Also a couple of times I forgot to mute the amp when switching turntable on and off and some loud popping took place there. You may have a point on that. And yes, I do not crank it up to any distortion level ever.

Anyone have any ideas why I get the popping from the fridg and turntable?

mjock3 · « **Reply #10 on:** 14 Apr 2011, 09:34 pm »

Yikes!!! $350.00 for a replacement driver

srb · « **Reply #11 on:** 14 Apr 2011, 10:10 pm »

Quote from: mjock3 on 14 Apr 2011, 09:34 pm

Yikes!!! $350.00 for a replacement driver

I assume that's a quote you got from Sumiko? That's fairly outrageous. A Scanspeak Revelator midwoofer, which is most certainly a much more expensive driver, goes for ~ $225.

You, of course, need to find the exact model replacement, as similar drivers will have different specs and parameters and wouldn't work as designed for your crossover and/or cabinet.

I did come across a forum post where one owner said there were no brand, model or other markings on his Concerto drivers. Is that the case with yours, or can you come up with a model no.? A quick eBay search unfortunately only found a pair of these 5.5" WO070001 in Hong Kong. http://cgi.ebay.com/Sonus-faber-TOY-5-5-MIDWOOFER-PAIR-NEW-BOX-/140535167693?pt=Speakers_Subwoofers&hash=item20b88c7acd

Steve

mjock3 · « **Reply #12 on:** 14 Apr 2011, 10:22 pm »

I tried getting a quote from a dealer on Audiogon but was told Sumiko wants me to use a local (State) dealer. I called them and they gave me the $350 quote. I did look while I had the woofer out checking connections and I did not see anything identifying the driver. I really did not think it would be that much for the driver. I guess I'll have to hold off on some other projects in the works.

srb · « **Reply #13 on:** 14 Apr 2011, 10:26 pm »

If you have identified the woofer as the driver that is distorting, you may want to rule out any problems with the crossover or other internal wiring and swap the woofers between enclosures to see if it does in fact follow the driver or the crossover/enclosure.

Steve

mjock3 · « **Reply #14 on:** 14 Apr 2011, 10:27 pm »

Great idea! Thanks Steve.

richidoo · « **Reply #15 on:** 14 Apr 2011, 10:39 pm »

It is expensive because it is obsolete part for an obsolete design. They got you. If it really is the driver, you must replace it with the original part to retain the performance of the original speaker.

I'd try to get the driver tested with a woofer tester to verify the specs are in the ballpark, and compare the broken driver to the good one. If you push the cone in slowly with your hand, do you hear it rubbing? If no rubbing and specs same, I would look for another explanation.

The pop from the TT is DC offset. The pop from the fridge is EMI (or RF?) from an old relay arcing. Unless it was loud as a gunshot it shouldn't hurt the woofer, but it might break from a minor pop if it was a runt close to defect like PEz said. But Scan drivers are not prone to defect.

HAL · « **Reply #16 on:** 15 Apr 2011, 02:47 am »

I would contact Parts Express and see if they can rebuild the original woofer. They maybe able to source the original parts to do the repair.

When I had B&W 805 Matrix and had a bad woofer, B&W rebuilt my original as the latest production were different. Saved big bucks at that time many years ago.

Just a thought.

mjock3 · « **Reply #17 on:** 15 Apr 2011, 06:50 pm »

Well here is the update. I swapped drivers and the distortion remained in the same enclosure?!?

What components in the crossover could cause this?

Thanks for all the help, much appreciated.

Mark

face · « **Reply #18 on:** 15 Apr 2011, 10:51 pm »

Quote from: mjock3 on 15 Apr 2011, 06:50 pm

Well here is the update. I swapped drivers and the distortion remained in the same enclosure?!?
What components in the crossover could cause this?

Thanks for all the help, much appreciated.

Mark

Bad cap possible. Pull the crossover take a pic for us.

mjock3 · « **Reply #19 on:** 16 Apr 2011, 04:35 pm »

I took the crossover board out and examined it and concluded things looked good. I put it back and hooked up again before I got previous post. Hooked things back up played at moderate levels clear as a bell.

Well, I have concluded it is else where and not in the speaker. When I did the speaker wire switch I must not have let it warm up enough. When amp is cool the moderate levels of music is clean as a whistle. But once it warms up it give the distortion out of right channel only at moderate levels. At low levels thing are fine. Going to try some tube swapping and bias check.

Thanks,

Mark