Speaker Problem Question

[admin_exported]

Hi,

I've just bought a pair of Mission 751's off ebay. The ad didn't say there was anything wrong with them.

I've connected them to a Marantz PM7001 with bi-amping and banana plugs.

One speaker sounds perfect.

The other speaker has a lot of crackling/distortion - which seems to be mostly/all on the bass.

I've tried switching the speakers around - and the same one still has the distortion.

I've checked the cables are the right way around. The bi-amp "seperates" is turned to off on the amp.

It sounds a little better if I use "source direct" (bypass the balance and tone control) but it doesn't fix it.

I'm not really sure what else to try - I don't have any 2-core speaker cable to try.

Could the speaker be broken? Or could they be incompatible with the amp? The amp output is 75watts at 8ohms and these speakers have a 75watt max at 6ohms - although I've read this doesn't matter as long as you don't turn the amp right up.

Feeling a bit gutted at the moment!

 

[MattSPL]

Are you saying that you have tried the left speaker on the left amp channel and the right speaker on the right amp channel and vice versa? And did the same speaker make the noise both times?

If so, it sound slike a damaged bass driver.

Hope it isn't

 

[Anonymous]

take the speakers to a mates house ... connect to his amp with is cables ... if you still have the same problem, and you bought the speakers off ebay, contact the seller and insist on a full refund (including return shipping)

from what you have said, sounds the one speaker is not working properly

 

[Anonymous]

I have left the cables in the same place and then switched each speaker (left one to right cables, and right one to left cables) around and the same speaker makes the noise.

I've just done that 'slight push' test - and the one with the distortion feels like something very rough and hard is behind it - the other one isnt like this - only very slightly in comparison.

What should I say to the sellar? Because they aren't really as described! The distortion is unlistenable.
Also - would it be worth fixing - rough cost idea? Is it something I could do without any experience - or would they need to be taken somewhere?

 

[MattSPL]

georgejack:dylan_uk:

Hi,

I've just bought a pair of Mission 751's off ebay. The ad didn't say there was anything wrong with them.

I've connected them to a Marantz PM7001 with bi-amping and banana plugs.

One speaker sounds perfect.

The other speaker has a lot of crackling/distortion - which seems to be mostly/all on the bass.

I've tried switching the speakers around - and the same one still has the distortion.

I've checked the cables are the right way around. The bi-amp "seperates" is turned to off on the amp.

It sounds a little better if I use "source direct" (bypass the balance and tone control) but it doesn't fix it.

I'm not really sure what else to try - I don't have any 2-core speaker cable to try.

Could the speaker be broken? Or could they be incompatible with the amp? The amp output is 75watts at 8ohms and these speakers have a 75watt max at 6ohms - although I've read this doesn't matter as long as you don't turn the amp right up.

Feeling a bit gutted at the moment!

Try turning your system off and gently pushing both bass drivers in ONLY SLIGHTLY with equal pressure right around the outer of the cone, if the one you seem to be getting distortion/crackling from feels like it's not moving as freely as the other driver, or as if it's scratching/catching on something, it's most probably been 'over run' at some point and has a burnt voice coil which is rubbing on the magnet channell. If it is that, it's not good and can't be fixed without replacing the driver..

Very good point, the 2 bass drivers in my DB1i's went at new years and melted in position. When i pushed them as described by Geargejack, they came un stuck and were rubbing as described on the magnet.

 

[Anonymous]

I just answered my own question...

I can get a replacement bass driver for £50.

If I replace one - should I replace the other one, or doesn't it matter?

Also - what would re-fitting entail? Do the wires at the back of the driver (I'm guessing this is how it works!) re-attach fairly easily, or is it a soldering job?

I guess I can only ask for a refund of one of them, but do you think it's reasonable to ask for the repair cost to be refunded - as they weren't described as one of them being broken?

 

[MattSPL]

dylan_uk:

I just answered my own question...

I can get a replacement bass driver for £50.

If I replace one - should I replace the other one, or doesn't it matter?

I guess I can only ask for a refund of one of them, but do you think it's reasonable to ask for the repair cost to be refunded - as they weren't described as one of them being broken?

Id replace both as if one went the other probably got a similar input signal that blew the other

 

[Anonymous]

Any idea how you fit a new one? Easy / hard?

 

[Anonymous]

dylan_uk:

.

What should I say to the sellar? Because they aren't really as described! The distortion is unlistenable.

Also - would it be worth fixing - rough cost idea? Is it something I could do without any experience - or would they need to be taken somewhere?

contact the seller immediately and tell him of the problem ... also tell him that you have been on this forum ... be polite ... and ask for his comment/suggestions

tell the seller that if he agrees, you will contact Wembley speakers in London (or a similar repair place), and seek advice and a cost to repair ... if the seller agrees, he should compensate you with the full repair cost (including the shipping and return shipping cost to have them repaired)

seller stated that the speakers were in good condition ... there is no way that the damage could have happened during transit ... sounds like 1 speaker is blown

 

[MattSPL]

dylan_uk:Any idea how you fit a new one? Easy / hard? I think your speakers may be like the mission 731i's i once had.

The drivers are mounted on rods from the rear of the cabinet so you need to unscrew rear panel unless you can see fixings round the drivers on the front baffle

 

[MattSPL]

MattSPL:

dylan_uk:Any idea how you fit a new one? Easy / hard? I think your speakers may be like the mission 731i's i once had.

The drivers are mounted on rods from the rear of the cabinet so you need to unscrew rear panel unless you can see fixings round the drivers on the front baffle

Just found a pic on the net and it has fixings on the front baffle round the driver. Just remove the screws then the driver should pop out

 

[Anonymous]

Thanks for the advice - I'm writing my reply now.

They have like allen key bolts all the way around the front and look like the pull out front-wards... here's a pic of the replacement: http://www.technosound.co.uk/content/eshop/SpeakerSpares/751.751F.LF.JPG

 

[MattSPL]

dylan_uk:

Thanks for the advice - I'm writing my reply now.

They have like allen key bolts all the way around the front and look like the pull out front-wards... here's a pic of the replacement: http://www.technosound.co.uk/content/eshop/SpeakerSpares/751.751F.LF.JPG

Yeah definite easy job, 10min per speaker. Butg as said, you dont want to be spending £100 or more to fix what you were told was a perfect speaker

 

[Anonymous]

I've sent my reply, he sounds like a nice guy so finger's crossed. I had my new turntable all set up and then felt like crying!

Thanks for all your help everyone.