Newly purchased "Perfect" Cornwall 1s: Bass frequency rattles

[Schofield]

Hey everyone, thanks for reading. It's my first post here. I'm audiophile but definitely not an audio equipment expert.

 

I just bought a pair of Cornwall 1s decorators. They were sold as perfect, unmodified condition. They are in amazing condition I would say, given their age. I listened to them prior to sale and they seemed fine.

 

When I listen at home, connected to a new budget level AV receiver (Sony STRDH590), they sound great. That is, except when playing very very low frequencies... the deepest bass sounds in a film, like the epic explosion or thunder, that's really meant to rock you in the chest or rumble your belly. In these moments, there is a tight, flub flub flub, even at moderate volumes (audio file attached). And it's in both speakers. The speakers are placed a foot away from the wall, about 8.5 feet apart.

 

The grills were semi-permanently attached by the original owner using a birch frame that is nailed to the cabinet. They have clearly been well attached and well taken care of. But this means I cannot inspect/report on the driver condition without removing these frames. The back panel can be removed, but I'm not sure what that would reveal.

 

Can anyone diagnose the issue? How serious would the repair be? Advice for further sussing out or reducing the issue? Any help would be much appreciated. I'm very happy with the speakers for music. This specific bass issue is a non-issue for music, since the problematic bass frequency is too low for the tracks I regularly listen to. At the same time, the speakers were not cheap ($2K for the pair). And I hope to slowly build a decent setup around them.

 

Cheers, Fellas. 

Sam

[ssh]

It sounds like they are not as advertised. At the price you paid, they should be. I'd take them back, if possible.

SSH

[OO1]

@Schofield , sounds like there's an issue with the amp , could be the eq settings when playing Digital files versus stereo ,  open the graphic equalizer from the menu and eq adjust the sound when playing movies     .

[wuzzzer]

Do you have any EQ added to the bass frequencies?

[Peter P.]

Yeah, the easy thing to test has been suggested; borrow another receiver and see if the problem remains.

 

I didn't think it was the receiver, however. To me it sounds like the woofers have come detached from the spiders, which control excursion.

 

But do the easy test first.

[JohnA]

Listening through my headphones, I hear a crackling that often indicates amplifier clipping (over-driving).  Your description of flub, flub, that i don't hear, could describe "port chuffing".  While normal, it *is* undesirable.  Your Cornwalls were not built with the massive lows special effects contain, so it it is port chuffing, all you can do is reduce the bass boost or the volume.  That will also reduce amp clipping.  If you have the bass boosted, reduce that the move them closer to corners and the walls to help recover that bass output. 

 

It's easy enough to remove the backs and inspect the woofers.  If they are damaged, replacements are readily available and also recone kits. 

[OO1]

On 4/16/2023 at 11:19 PM, Schofield said:

 

 

The grills were semi-permanently attached by the original owner using a birch frame that is nailed to the cabinet 

  open the backs   ,  vacuum  any dust between the grille fabric and the lower ports   ,  the air passages  must vent 

(   can you post a picture of the grilles )