Brand new Forte IV static distortion on certain frequency.

[bryan0101]

I just purchased a pair of new Forte IV online from one of the reseller, and notice that 1 of them is producing hoarse static distortion noise around certain frequency (playing piano pieces). 

 

Contacted the seller, and waiting for the reply. 

 

But very disappointing that a brand new pair has this issue from klipsch, QC should have caught it. 

Edited December 30, 2022 by bryan0101

[chuckears]

The brand new pair of original-series Fortes I unboxed myself back in 1988 had a midrange blown - I could tell from vocals, mainly female, which provided a bit of a static rattle, if my acoustic memory serves.

I loaded it up and took it back to the showroom, where they swapped out the mid horn with one in a model they knew worked just fine.

 

It's still running sweet, some 34 years later.
Hopefully, you can be back up and running with it soon...

[wuzzzer]

A lot of piano music sounds terrible on any speaker.

[rebuy]

28 minutes ago, wuzzzer said:

A lot of piano music sounds terrible on any speaker.

Not on my system, it sounds Marvelous.  😃

[chuckears]

12 hours ago, rebuy said:

Not on my system, it sounds Marvelous.  😃

Same with mine… Chorus IIs powered by plenty of dynamic headroom make the larger instruments sound incredible :-).

[amped]

Have you tried switching L to R and R to L channels to make sure it’s the speaker and not something else?

[bryan0101]

It was the K702, the diaphragm was defective. The reseller sent me another and its now singing  beautifully. I can see the Forte staying for very long time.....

[billybob]

There you go... cool.

[OO1]

2 hours ago, bryan0101 said:

It was the K702, the diaphragm was defective. The reseller sent me another and its now singing  beautifully. I can see the Forte staying for very long time.....

Did they send you a new  driver , or just the  diaphragm

[bryan0101]

They sent me the whole new driver. I believe only klipsch or the oem factory can redo the diaphragm. I tested with all the genres from spotify I can think of, and it's good now. And yes, forte iv sounding life-like and awesome. I'm using it as main instead of my usual sopra to break-in as well as hooking up my dual rythmik F12Gs to it for the 20-50 region.

 

Would love to find the schematic for the crossover and see if they can be upgraded in the future.

[OO1]

On 1/17/2023 at 7:20 PM, bryan0101 said:

 if they can be upgraded in the future.

 you would have to wait for  a couple of years for a Forte V  kit ,   currently there is a kit to upgrade a Forte III into a Forte IV  

[sixspeed]

I had the SAME exact problem the OP described on one of my Forte IV's as well. Noticeable on certain piano hits and sine wave like sounds mostly, an obvious shrill distortion of the driver with a slight static to it. Layer sounds, voices and pink noise do not trigger the issue. It's a very specific frequency and sound type where the distortion occurs and is VERY audible.

 

Except in my case it was fine for the first 5-6 months and about a week after a thunderstorm which caused a power outage, one of the Class AB Bryston 2B-LP pro amps I was using in bridged mono, 1 for each of my Forte IV's blew up and had a brief loud static sound and the sound cutout after that.

 

Swapped in a pair of Crown XLS 1002's I had in storage for a few years on both Forte IV's which didn't sound nearly as good but sound was back for a couple weeks. The other Forte was perfect but afterwards the left side one had the distortion exactly like the OP stated. It got better when I later replaced the XLS' which were temporary with Schiit Vidar IIs as Bryston's USA repair facility was shutdown and I haven't got around to sending both for a full restoration to them in Canada. But the Vidar is everybit as good as the late model 2B-LPs with XLR inputs and detachable power cables I was using. Sonically a seamless match for the 9BSST2 powering my other 4 channels. So I may just leave the Vidar in there even after the 2B-LPs get restored.

 

I partially blame myself for not having surge protection for the 2 amps that run those Forte's which sit on the lower shelf of each stand they're on but the peak output of that loud brief noise when the amp blew up couldn't have been more than 60-100 watts tops. Well within the rated peak input of the Forte but compression drivers are fragile to snafus like that. I wouldn't be the first to blow up a driver lol. First time in 20+ years I ever had an amp suddenly and spectacularly blow up on me like that. So whether it was a coincidental driver defect occurring with the amp failure, a combination of both or entirely because of the amp I'll never know. The OP's case leads me to believe that 702 driver is perhaps not quite as robust as it could be. Although my KHorns arrived years ago with one of them having a busted K77D which I presume the internal magnet/voicecoil was damaged during shipping. Klipsch sent me a new 77D for it and they've been singing ever since. Major PIA getting in there though, changing a Forte driver is way easier.

 

Just glad to see replacing the 702 midrange solved the OPs issue which was identical to mine. It sounded like the midrange horn driver anyway. Ironically before I saw this I just ended up ordering the III to IV upgrade kit, 2 of them so I can just replace both mid/hi drivers on both of my Forte IV's for peace of mind so they break in from new identically again. Thankfully the woofers and passive radiators are perfect. Klipsch would have only replaced the defective driver.

 

I wonder if anyone else had had their 702 midrange go bad as well but this is the only other thread I have seen on this. Glad I wasn't alone. The speaker sounds and looks phenomenal otherwise. I felt it was the best overall speaker value/performance wise of the updated Heritage models with the new drivers, phase plugs and crossovers. But after the 2022 price hike the Cornwall is the better deal. I only needed Forte's though for my room and that was that.

 

Six

[Ceptorman]

1 hour ago, sixspeed said:

I had the SAME exact problem the OP described on one of my Forte IV's as well. Noticeable on certain piano hits and sine wave like sounds mostly, an obvious shrill distortion of the driver with a slight static to it. Layer sounds, voices and pink noise do not trigger the issue. It's a very specific frequency and sound type where the distortion occurs and is VERY audible.

 

Except in my case it was fine for the first 5-6 months and about a week after a thunderstorm which caused a power outage, one of the Class AB Bryston 2B-LP pro amps I was using in bridged mono, 1 for each of my Forte IV's blew up and had a brief loud static sound and the sound cutout after that.

 

Swapped in a pair of Crown XLS 1002's I had in storage for a few years on both Forte IV's which didn't sound nearly as good but sound was back for a couple weeks. The other Forte was perfect but afterwards the left side one had the distortion exactly like the OP stated. It got better when I later replaced the XLS' which were temporary with Schiit Vidar IIs as Bryston's USA repair facility was shutdown and I haven't got around to sending both for a full restoration to them in Canada. But the Vidar is everybit as good as the late model 2B-LPs with XLR inputs and detachable power cables I was using. Sonically a seamless match for the 9BSST2 powering my other 4 channels. So I may just leave the Vidar in there even after the 2B-LPs get restored.

 

I partially blame myself for not having surge protection for the 2 amps that run those Forte's which sit on the lower shelf of each stand they're on but the peak output of that loud brief noise when the amp blew up couldn't have been more than 60-100 watts tops. Well within the rated peak input of the Forte but compression drivers are fragile to snafus like that. I wouldn't be the first to blow up a driver lol. First time in 20+ years I ever had an amp suddenly and spectacularly blow up on me like that. So whether it was a coincidental driver defect occurring with the amp failure, a combination of both or entirely because of the amp I'll never know. The OP's case leads me to believe that 702 driver is perhaps not quite as robust as it could be. Although my KHorns arrived years ago with one of them having a busted K77D which I presume the internal magnet/voicecoil was damaged during shipping. Klipsch sent me a new 77D for it and they've been singing ever since. Major PIA getting in there though, changing a Forte driver is way easier.

 

Just glad to see replacing the 702 midrange solved the OPs issue which was identical to mine. It sounded like the midrange horn driver anyway. Ironically before I saw this I just ended up ordering the III to IV upgrade kit, 2 of them so I can just replace both mid/hi drivers on both of my Forte IV's for peace of mind so they break in from new identically again. Thankfully the woofers and passive radiators are perfect. Klipsch would have only replaced the defective driver.

 

I wonder if anyone else had had their 702 midrange go bad as well but this is the only other thread I have seen on this. Glad I wasn't alone. The speaker sounds and looks phenomenal otherwise. I felt it was the best overall speaker value/performance wise of the updated Heritage models with the new drivers, phase plugs and crossovers. But after the 2022 price hike the Cornwall is the better deal. I only needed Forte's though for my room and that was that.

 

Six

Why would Klipsch be liable for a blown driver from an electrical surge?

[sixspeed]

On 6/23/2023 at 5:35 PM, Ceptorman said:

Why would Klipsch be liable for a blown driver from an electrical surge?

 

I never said they were liable in anyway at all which is why I purchased new drivers instead of going through warranty. I even said I blamed myself for not running a surge protector on that amp and that Klipsch only would have replaced the bad 702 driver (and rightfully so). So since I didn't want to have uneven broken in mid/hi horns, I ordered the kit to replace both horns in the pair.

 

Not sure how you inferred that I ever said they were liable for what occurred at all. I clearly said the problem only occurred after an amp blew. It's just rather curious the nature of the defect that happened to the driver was identical to the OPs who did not have an amp/electrical related issue and his was like that new.

 

Going just off rated specs verbatim the fact that it blew the driver (or partially blew it) means at one point the 702 received better than 100W sustained for long enough to damage both the amp and the driver. The loud percussive pink noise like sound when the amp blew was only a second or so long after which it stopped outputting sound.

 

First time I ever had a driver or amp blow up on me and I've had 10s of power surges over the 2 decades I've been into the hobby. Many of those years with Klipsch speakers serving me reliably and well and this incident doesn't change how I feel about that one bit.