Issue with ProAc D40 speaker - any suggestions to resolve the issue


Hi,


I recently bought used ProAc D40R couple of months back, and driving them with Bluenode streamer —> Digital Audio company Marachino Class D Mono blocks.


After a month or so I realized that absence of the sound from one of the ribbon tweeter, showed it to local audio equipment dealer, they fixed the issue (it was loose tweeter harness wire), now I get the sound from both the tweeter.


Recently i compared these speakers against my exiting DIY Audio Nirvana 8” Alnico single driver speaker using ‘Spanish Harlem’ Track by Rebecca Pidgeon, to my surprise Audio Nirvana sounded more clear and I can hear all the details especially shakers in the left back corner and all other details while on ProAc D40r I can barely hear all those tiny details in the background to me that should not happen with ProAc being such great speaker especially with Ribbon tweeter, so just wondering What could be the issue, Can it be a Crossover Caps issue (as the person I bought these from mentioned those were in storage for almost a year and I read it somewhere here on audiogon thread that caps in crossover may go bad if you store it for long time). 

Really appreciate any recommendations/remedies to resolve the issue, eventually i will have take it back to audio dealer but just wanted to check on forum that if anyone else experiences this kind of issue and what was the solution.


Thank you,



listener111
If there is a defect (hard to know without doing a frequency sweep and using proper measurement equipment), it may be a crossover component, wiring fault, or faulty driver. Caps are unlikely to just fail after being in storage for 1 year, but that doesn’t mean there isn’t a fault somewhere.

In the meantime, perhaps do some basic testing with a microphone app. Level match the amp volume to the speaker outputs at a given frequency using a test tone (e.g. 261hz, middle C), then compare the volume levels at different frequencies. Ensure also the volume levels match between the individual left and right Proacs.

Not sure what frequencies shakers are at; going off of hi-hats and cymbals, have your testing include the 2khz-3khz range, and up from there, if we're suspecting there's an issue with treble reproduction. 
Thank you motokokusanagi, will try comparing the speakers with level matched though as this will be first attempt to do that so will have to wait and see how it goes.
Sure thing. The crossover frequency should be between 2-4khz. You can verify any gross discrepancies in volume output using your phone, using the old speakers as a control, then the left and right Proacs, and both together. Find some percussive music also and do a sanity check if you find a discrepancy using just test tones. If you find a drop in volume output between the individual speakers of -3db or more, then there's a fault.

Subsequent fault diagnosis would require removing the drivers and crossovers.
wow sorry to hear you are having that problem

i have had 8-10 pair of various proacs since the 1990’s...even moved two pair to asia and back when i worked there... i have never had a single driver/x-over problem like that

yes you need to find a tech do a proper sweep of the drivers and crossovers make sure all is working properly... even though a d40 has prodigious bass there is no way the speaker should obscure detail like that!!! won’t be cheap or easy to accomplish... at any time but especially now with covid etc etc
Thanks Milpai,
Even though the bass is more than Audio Nirvana it’s not really overpowering and seems fine as its same as what i used to get from Usher CP 6381 i used to own. (though i will try pulling those further away from wall and will see if that makes any difference). The sound is not as balanced, there is not much depth to soundstage as compared to audio nirvana or other speakers i used to own. based on what i am reading D40R should sound much better. I even saw few other videos of other ProAc speakers playing "spanish harlem" and i hear those tiny details through my headphones on youtube video but can’t hear much with D40r
Thanks jjss49,

looks like that is the only option i have, will see if i can take it to local audio dealer over the weekend. Just trying to figure out if there is something i can do before i take it back to the local dealer.
@rcprince might be right. @listener111 mentioned previous diagnosis said tweeter wiring was loose. IIRC, Proac crossovers generally have the tweeters connected in reverse polarity. They’re probably attached using quick connects, so if you felt up to it, carefully unscrew and remove the tweeters and check the wiring and connections are consistent both left and right. If one is not wired the same as the other, rewire it so that both are the same and see if that fixes it. It might be wired after the last "fix" so that they’re now out of phase and cancelling each other out left and right.

Levels discrepancies from 2-3khz and above would occur if that is what’s happening if you still wanted to test that way.

Hopefully Proac’s internal wiring cable distinguishes positive (e.g. red) and negative (e.g. black) legs. If reverse polarity, then the black (negative cable) would be going to the positive tweeter terminal (usually marked with a red dot)

Otherwise, http://www.troelsgravesen.dk/polarity.htm
When I bought my d30r, one of the tweeters was not working and it was due to loose screws that held the crossover board to the back of the cabinet just on the other side of the binding posts.  The screws can be tightened by removing the woofer driver. I'm not sure if that is your problem as well but maybe a good idea to check. 
Thank you rcprince and jaferd, i will see if i can remove the woofer and tweeter to check the connections.
listener

let us know... hope it is something simple as has been suggested!!
sure, sorry just was busy in work whole day hopefully over the weekend i will open the drivers and will check and will let you know.
Hi,

I was able to look at woofer connections, tweeter connections, seems to be all right, was unable to see anything that is wrong just by looking at the crossover (unfortunately don't know much about the crossovers), so looks like i will have to take it to the local dealer in next few days, will let you know if dealer comes back with anything.

Thanks,
Did you check to see if the screws holding the board to the back was tightened? 
Thanks for the suggestion Jaferd, looked at the boards (inside for the speaker binding post) and those looked secure as well.
Took the speakers to the local dealer, really nice Guy (Who fixed the tweeter connections a month back), we connected speakers to Naim power amp (not sure which one) and he listened to the song that he normally use to evaluate the speakers and told me there is nothing wrong with the speakers and eventually we listened to ‘Spanish Harlem’ Track by Rebecca Pidgeon as well, at the time at the shop i was able to hear the details those were missing at home (shakers in the background) .. the reason I believe is that volume was way up (I normally do not listen at that volume at home), as well as there was huge space around the speakers behind as well as on the side .. which is not possible at home. Brough speakers home and listened at high volume i can hear the details but only at high volume (bass is more pronounced as well and sometimes overpowering at high volume), Audio Nirvana single driver speakers are more reveling and forward sounding, as those are high efficiency i can hear those details at low volume. Will give it some more time will play positioning as well as with the cables/other components will look into getting the better DAC / different pre amp (currently the bluenode directly feeds into Class D mono blocks).

Thank you for all for helping me out figuring out what’s the issue with the speaker (looks like there i stone except that Audio Nirvana are more efficient and more detailed at low volume than ProAc’s)