Mission 752 Freedom problems

[Rogerdodge]

Hi
I've just got a set of 752F, wanted these ever since I first heard them over 20 years ago. My system up until now was Mission 733i's, Marantz CD63se KI and a old A&R Cambridge Arcam Alpha. On hooking up the 752F's i was quite disappointed at the harsh treble on high voices. I did't have this problem with the 733i's, any clues as to what i can do would be most appreciated.

[Macca]

could be any number of issues.

If you're certain the speakers are not faulty or damaged I'd look to the amplifier. If it was fine with the 733i it should be fine driving the 752. But maybe not.

[Gazjam]

From memory of hearing the 752f’s back in the day, they were smooth but very clear...no treble harshness?
Also the Freedom version moved from a mesh dome metal tweeter to a silk dome, so more reason for there not to be harsh treble?

[Lawrence001]

I've seen threads like this to round in circles and drive people nuts eg Mike's valve amp thread. What you need is a second (experienced) opinion. Given there we are with lockdown this is tricky for a while.

As an alternative, I'd suggest getting a frequency generator app on your phone and plug it into the amp with a headphone to RCA lead. Run frequency sweeps on one speaker at a time. If you can't hear any obvious resonances then it's more likely to be a sensitivity to the speaker.

Have you given then a few days to bed in? Sometimes they sound better after a while. Whether that's due to them being run in (if they've not been used) or your ears getting used to them is a controversial subject but either way it often helps.

If there's nothing obvious then I'd suggest putting them to one side and keeping the old ones going until you're in a position to have visitors.


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[Filterlab]

What speaker cables do you have Rog?

[walpurgis]

I'd be inclined to try new capacitors and if the tweeters come apart, new ferrofluid.

[Rogerdodge]

They look in exceptional condition from what I can see

[Rogerdodge]

From memory of hearing the 752f’s back in the day, they were smooth but very clear...no treble harshness?
Also the Freedom version moved from a mesh dome metal tweeter to a silk dome, so more reason for there not to be harsh treble?

That is how I remember them, which is why I wanted them?

[Rogerdodge]

could be any number of issues.

If you're certain the speakers are not faulty or damaged I'd look to the amplifier. If it was fine with the 733i it should be fine driving the 752. But maybe not.

They look in exceptional condition from what I can see, I know that may not be the whole story. I think the amplifier is ok even thought it is over 30 years old.

[Rogerdodge]

I've seen threads like this to round in circles and drive people nuts eg Mike's valve amp thread. What you need is a second (experienced) opinion. Given there we are with lockdown this is tricky for a while.

As an alternative, I'd suggest getting a frequency generator app on your phone and plug it into the amp with a headphone to RCA lead. Run frequency sweeps on one speaker at a time. If you can't hear any obvious resonances then it's more likely to be a sensitivity to the speaker.

Have you given then a few days to bed in? Sometimes they sound better after a while. Whether that's due to them being run in (if they've not been used) or your ears getting used to them is a controversial subject but either way it often helps.

If there's nothing obvious then I'd suggest putting them to one side and keeping the old ones going until you're in a position to have visitors.


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I will try the Frequency test. As you say it's difficult at the moment to get another pair of ears

[Rogerdodge]

What speaker cables do you have Rog?

I'm using QED 79 Strand

[Rogerdodge]

I'd be inclined to try new capacitors and if the tweeters come apart, new ferrofluid.

Okay that is something I will look into :)

[Macca]

What's the source Roger?

[Rogerdodge]

What's the source Roger?

It's a Marantz CR63SE KI

[Rogerdodge]

It's a Marantz CR63SE KI

I also have a Rega Planner 3 to connect at some time when space allows (1985 version)

[Macca]

it's a sweet sounding player, almost gentle, so don't think that's the problem.

I'd try a different amp just to eliminate that possibility. Borrow one or buy one cheap second-hand. Always worth having a back-up amp in any case.

If you are cranking it up a bit then it could be the amp clipping on the peaks as it is pretty low powered. Probably not that but worth checking. If you get the same break-up even at very low levels then it's not a clipping issue.

[Rogerdodge]

it's a sweet sounding player, almost gentle, so don't think that's the problem.

I'd try a different amp just to eliminate that possibility. Borrow one or buy one cheap second-hand. Always worth having a back-up amp in any case.

If you are cranking it up a bit then it could be the amp clipping on the peaks as it is pretty low powered. Probably not that but worth checking. If you get the same break-up even at very low levels then it's not a clipping issue.

Okay, I'll try getting hold of another amp, thanks

If I was to buy myself another amp would you have any suggestions? Would I be better buying new or classic?

[Macca]

Okay, I'll try getting hold of another amp, thanks

If I was to buy myself another amp would you have any suggestions? Would I be better buying new or classic?

If you don't want to spend big I'd suggest getting one of these second hand http://www.hifi-review.com/150474-nad-c320bee.html - I'm using one at the moment. Gives almost nothing away to much more expensive amps (I've got lots!) and was only £110 delivered off eBay.

[Filterlab]

So not the source or the cables, or the speakers of all is well. The NAD will work a treat with that combo.

[fatmarley]

new ferrofluid.

That would be the first place I'd look.

[Rogerdodge]

Now got a budget of about £500 for an amp, any suggestion new or pre-loved?

[Stratmangler]

If you don't want to spend big I'd suggest getting one of these second hand http://www.hifi-review.com/150474-nad-c320bee.html - I'm using one at the moment. Gives almost nothing away to much more expensive amps (I've got lots!) and was only £110 delivered off eBay.

I have been running a C320BEE since 2003 (bought it new from Richer Sounds, and then it was £220.00 IIRC), and it's a great amp.
And as you've already said, it gives very little away to much more expensive amps.

My son has an Arcam Alpha 7R, and it is another great sounding, built like a tank amplifier.
They can be had for sensible money on Ebay.

[Lawrence001]

Stick the old speakers back in just to check. You never know something could have happened at the same time you changed over.

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[Filterlab]

See if you can find a minty Arcam Diva A85 - you should get one for £350-ish. Blummin' wonderful amps for the cash. I have one in my second system (but it's staying there). :lol:

[Rogerdodge]

Stick the old speakers back in just to check. You never know something could have happened at the same time you changed over.

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I have just done that and the sound was still there but not as pronounced, it turns out the vocal on the track I was listening too had a strange effect on it. They sound great with everything else, just a bit of bass missing form from what I like.

[Rogerdodge]

See if you can find a minty Arcam Diva A85 - you should get one for £350-ish. Blummin' wonderful amps for the cash. I have one in my second system (but it's staying there). :lol:

I'll have a look, thanks

[Rogerdodge]

An update on what I've done.

I've managed to get an Arcam SA20 at a great price pre-loved. Although better I was still not entirely happy. Today I thought I'd download the manual for the speakers and it mentioned that before you use them that you check that the drive unit screws are all tight, not heard of this before? Anyway I've checked them and I couldn't believe that the were all loose! So the noise I've been hearing is vibration, they are now sounding sweet and I'm really happy :)

ps thanks for everybodys input :)

[Filterlab]

Nice. Very often the answer is so simple it evades many.

[Lawrence001]

Good call I always check this when I buy a pair of speakers I should have thought of it.

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