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I have a pair of 805s speakers, which I've had since new.
They've always sounded a bit flat; great bass and mid range but a bit muddled. I was using 605 speakers, for surrounds, and would use all 4 speakers when listening to music, which improved the situation.
So, moved into a barn style residence a couple of years back: cavernous space with concrete floor and mix of corrugated steel and gyprock walls. Kids were older now and I could turn music up. Sound in barn was more " muddy" and listening at loud volumes was not pleasant. I put this down to my amp, the terrible room acoustics and wondered whether my Monster cable bi wire cables were not up to standard.
So, changed old amp, Yamaha RX-V 3077, to a Marantz SR8015. Huge improvement and loud volume listening definitely better. Sat speakers on Isoaccoustic stands and another leap forward but still something missing. Still found listening to "all speaker stereo" added something ( surrounds now a combination of B&W M-1 and AM-1 speakers).
Then changed speaker cables to Van den Hull CS 122 Hybrid cables, bi-amped on the Marantz, again an improvement but same problem.

 

Now the next part is embarrassing, as I can't believe I hadn't tried this long ago.
Whilst playing music, I pulled out the cable going into the top of the Left speaker which made absolutely NO difference to the sound. Tried the same with the Right speaker, and again NO difference. Then ran speaker cable straight from Amp, not bi amped,  to TOP terminals of the speaker. No sound.

Only the  bottom terminals will deliver sound, upper terminals currently ornamental. ( still can't believe I didn't try this years ago). 
I can still hear cymbals / high hats, but softly (quite a testament to the ability of the 805s driver). I suspect upper terminals aren't merely ornamental and I'm missing out on a lot of high range.

So, HELP!
Now, both speakers are the same. Physically they are essentially "as new" and tweeters slightly dusty as I've never touched them, but undamaged. I can't remember any incident of damage, nor any period of abnormal sound coming from the speaker.
So, is this a fault/ breakdown and what could be the possible source? Anything you could suggest for me to try ? Any suggestions would be much appreciated. It's quite incredible the 805s are currently sounding as good as they are, without the high frequency, but I would love to hear them at their full potential.

I live near Sydney.

Many thanks in advance.

 

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You could disconnect the tweeters from XO and test resistance of the tweeters with a DMM and see if they are OK.

 

That would be my first check.

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Looks like there is a molex connector inside that connects wires from the XO to the tweeter, you can unplug there and test the tweeter from there.

 

IMG_20200503_205334.thumb.jpg.1a688d6539029ca48bdb2daa529d9e04.jpg

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Thank you for the reply, effort and photos Muon. A bit intimidated removing driver but seems just undo screws; is there some glue there as well?

Ok, so ignorance again, but what is XO? Where do I check the resistance and what should this be? Is this with terminal unplugged ?

I assume this would differentiate between tweeter and crossover as source of problem?

 

Thanks again.

 

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ok, again pardon the ignorance, would there be measurable voltage out of crossover with source playing. Is this potentially damaging to XO to check with DMM while source playing?

 

Thanks again.

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So, had been using Monster Bi Wire cable: L and R plus into front channel on amp, L "High Pass" plug to top L terminal on 805s, R HP plug to upper R terminal on 805s, L "Low Pass" speaker cable plus to lower L terminal on 805s and R HP plug to R lower terminal.  Thought problems with sound due to challenging room acoustics. Finally frustrated enough to removed one of the upper terminal speaker plugs: no difference to sound at all.

Then changed amps and cables. Ran cables in bi amped fashion using same amp: FL amp output to lower left terminal, FR to lower R,  FL amp 2nd output to upper Left terminal and 2nd FR to upper R. Sounded much better new amp, even better with a day of running in Van Den Hul cables. Then, tried removing plug at upper L terminal: no difference or loss of sound coming from speaker. Then plugged back in upper and removed a lower plug: no sound at all. Reveres amp outputs, i.e main amp outputs to upper speaker terminals, 2nd amp to lower terminals: similar sound and same issues: unplugging top terminals , no change in sound, unplugging bottom terminals : no sound. 

Then change amp configuration back to single amp output: only sound output if connected to lower terminal.  Then added jumpers from lower terminals to top, as per B&W, and again nil change in sound when top plugs removed. 

Now back to single amp configuration to lower terminals, I've left top plugs attached to 2nd amp output but not using . Photo attached.

 

Thanks.

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Photos would really helping and not just the speakers terminals. Something like this and how you connect to the amplifier with perhaps the front as well showing the settings since you using an Av receiver. 
side note with these speakers a 2ch stereo amplifier with Av bypass would be more appropriate to drive the 805 than Av receiver even if it’s a flagship one. 

Neo

151CB8DE-E7FE-4C7A-8D03-67AC5FA31968.jpeg

Edited by Neo
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Don't measure anything with the speakers in use!

 

Measure resistance (not voltage) with the DMM with nothing attached to the speakers..

 

But first post some pics and answer questions like others have requested.

 

 

Edit: if you are not comfortable removing a driver and measuring resistance ect', it might be best to get a professional to check your speakers.

Edited by muon*
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Thanks. Had trouble attaching previously.

Now driving through front L an R on receiver with my temporary jumpers ( original jumpers doing service with 685 speakers in man cave).

Updated receiver in our HT system, 9.1.2, and since started process have refound my joy for my music, so an enjoyable  step wise progression with a dedicated 2 ch amp down the line. I did want to try bi-amping with 4 Chanels off the Marantz first: 2 Chanels available and step wise progression as stated.805s.pdf

1850169730_805s3.pdf 805s Fault.pdf

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Think they're up now.

 

Thanks Muon that's why I ask before I do and ask some very basic questions so Im not assuming. I enjoy tinkering, don't like breaking.

 

So if I get game enough to remove drive, use DMM with red/black wires down from  tweeter. Any idea what the resistance should be?

805s.pdf

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Sorry, photos not opening as others have shared above?

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21 hours ago, Medart said:

Think they're up now.

 

Thanks Muon that's why I ask before I do and ask some very basic questions so Im not assuming. I enjoy tinkering, don't like breaking.

 

So if I get game enough to remove drive, use DMM with red/black wires down from  tweeter. Any idea what the resistance should be?

805s.pdf 19.09 MB · 12 downloads

The resistance reading of the tweeter will be a little less than it's impedance figure, so a 8 ohm tweeter might read 6.8 ohms resistance give or take.

 

But I thought you had your sound back now?

 

Or did I misread?

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Sorry for long explanation .

In short, tried various configurations but no change to sound when upper plugs removed.

Main driver providing some highs, but nil change to sound with upper terminal disconnected or connected ( whether directly to amp or jumper lead to lower terminal:: only lower terminal provides sound).

I've sent a message to B&W support and see if I get a response.

Seems unusual both speakers doing same thing. 

Thanks. 

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Sorry Muon, just looked at earlier post: meant the photos were up. 

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Thanks mate, was struggling with that. Using MacBook , kept uploading as PDF, no matter what I tried. 

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So, response from B&W support:

 

 
"Many thanks for getting in touch; we're sorry to hear of the issue you have described.
 
It would be nigh on impossible to identify the origin of the fault after this amount of time, especially, if the tweeters have been inactive for all, or the majority of this time.
 
I would be inclined to make use of the experience of your nearest dealer and take the speakers to them, to inspect and ascertain whether there is any fault now with the crossovers (unlikely, but possible).
 
We can no longer supply parts for models of that era, but they may be within the realms of someone like Loudspeaker Design & Restoration, to repair them.
 
For your local dealerships, please use our dealer locator if you need to:
 
 
For Loudspeaker Design & Restoration Services
 
 
Many thanks,
 
Neil
Customer Technical Support"
 
 Shame its a 3-4 hour round journey to the dealer from where I live. Disappointing no suggestion other than to take to a dealer.
 
Should I assume most likely tweeters are damaged? I've come across a few 805s videos online regarding tweeter changes as well as B&W schematics. I'll contact dealer but may try checking tweeter resistance prior to making a road trip. 
 
Ill let you know how I go. 
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So, armed with a couple of YouTube tutorials, removed tweeters. Tested resistance at tweeter terminals, with tweeters still connected to crossover: reading 8-14 ohms. Disconnected tweeters and checked resistance at tweeter terminals again: OL.

Wanting to play further with multimeter, tried lower input terminals of speakers themselves: 8-14 ohms. Then tried upper terminals on speakers: OL.

So, I assume both tweeters are blown. Have ordered x2 quoted "original" tweeters, which were posted from Netherlands same day. Estimated 10 working days to get here, can't wait.

I'll let you know what transpires.

 

Also contacted B&W again, who provided much higher level of support than their initial reply. Thanks Neil.

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I'm confused

 

Did you test tweeters alone by disconnecting the tweeters and placing the DMM probes on just the tweeter plus and minus without involving any other parts?

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Sorry Muon. Yes.

Tested, firstly , with tweeter still connected to XO:      8-14 ohms

Then, disconnected tweeters and pulled them out of housing. Reading on disconnected tweeter only: OL

 

Hope that clarifies

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  • 2 weeks later...

Okay, so a happy ending!

Ordered tweeters through Good HiFi, from Netherlands. Tweeters sent same day, noted on Post NL tracking, but delay through journey. 

Arrived today, in B&W packaging so would seem genuine. Out with old tweeters and in with the new and wow, speakers are back to life. Can't wait till the morning to pump up the volume!

Many thanks to those that offered advice and Myrko and  Maroesjka at Good HiFi.

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Thanks Pops.

Well put, it is  like having new speakers, wow.

Still most embarased I didn't realise both tweeters had failed, ouch to audiophile ego. The positive is that the journey making incremental changes, ( new receiver, speaker cables, isoacoustic stands and Bluesound node with USB of my lossless music) has reignited the hi fi bug in me and most worthwhile as my home music has never sounded better! 😁

So now  temptation to roll on with next purchase: ? a dedicated amp for the 805s's leaving the Marantz 8015  feeding the rest of the HT speakers. Will try to hold the bug at  bay for now and just enjoy my collection again and system as is. Ponder that at a later point.

 

 

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