My speakers sound amazing!

[Hifi_swlon]

So, after a lot of messing around with DSP, cables, placement, footers, EQ, etc - all trying to get a bit more bass slam that I felt the room was sucking out - I tightened my LF drivers yesterday by chance (the tool finally came to tighten a replaced driver so went to check the rest and they weren't what I'd call tight).

The upshot, they sound bl***y great!

Bass is how I remember a demo pair (in their room) - the bass I've been wondering where the hell it's been for a year. But not just that, everything sounds great, and the treble less harsh. Soundstage is better. The whole sound is less fatiguing.

Bearing in mind my post over in the speaker cables thread, am I imagining this, or could it actually be possible? Could it really be that simple? OMG if it is I'm a total moron (albeit a happy one, other than the fact that I might have needlessly worsened my hearing over the past year).

[ogs]

So, after a lot of messing around with DSP, cables, placement, footers, EQ, etc - all trying to get a bit more bass slam that I felt the room was sucking out - I tightened my LF drivers yesterday by chance (the tool finally came to tighten a replaced driver so went to check the rest and they weren't what I'd call tight).

The upshot, they sound bl***y great!

Bass is how I remember a demo pair (in their room) - the bass I've been wondering where the hell it's been for a year. But not just that, everything sounds great, and the treble less harsh. Soundstage is better. The whole sound is less fatiguing.

Bearing in mind my post over in the speaker cables thread, am I imagining this, or could it actually be possible? Could it really be that simple? OMG if it is I'm a total moron (albeit a happy one, other than the fact that I might have needlessly worsened my hearing over the past year).

Very pleased to read this! Loose drivers can have all sorts of effects. Lack of bass impact is certainly one of them. I once had a pair of speakers with two bass units in each. The stereo image was drawn to one side and I could not understand why. Then I discovered that one of the bass drivers was not tightened properly. After fixing this the stereo image was nicely centred!

[Hifi_swlon]

Interesting.

I mean they weren't loose so to speak, just not tight. I could turn the bolts with practically no force so just carefully finger tightenened them further. They're only a 2.5mm allen bolt so I'm guessing not designed for huge force.

No idea whether PMC don't tighten much, or they'd loosened over time with the previous owner (who said they had very few hours as a demo pair).

Either way they sound much more like the pair I demoed.

The question now is - how tight should they be?! I don't want to overtighten. For now they sound great so am leaving them. Have asked PMC but no reply so far.

[Axel]

Interesting.

I mean they weren't loose so to speak, just not tight. I could turn the bolts with practically no force so just carefully finger tightenened them further. They're only a 2.5mm allen bolt so I'm guessing not designed for huge force.

No idea whether PMC don't tighten much, or they'd loosened over time with the previous owner (who said they had very few hours as a demo pair).

Either way they sound much more like the pair I demoed.

The question now is - how tight should they be?! I don't want to overtighten.  For now they sound great so am leaving them. Have asked PMC but no reply so far.

I checked the bolts on my ProAcs recently and found that they were not fully tightened. I got the right sized Allen key out and proceeded to tighten them, tightening one, then the one opposite and so on.
I cranked them down as much as I could, bearing in mind that they were fairly small bolts into soft wood.  I couldn't detect any change in the sound, but it's pretty obvious that if the driver can move, then your  SQ will suffer.

[Rufus McDufus]

Torquing up the screws so that they were all equal is something I used to play with quite a lot back when I had Linn speakers. There tended to be an optimum torque level. Of course especially with speakers you have to be *really* careful not to break anything such as over-tightening and pulling captive nuts through the wooden surround or however they're constructed.   
I'm rather disappointed  speaker manufacturers in particular don't appear to use fixed torque settings when assembling them.   Veering off at a tangent (no pun intended) to circuits boards, I've also found manufacturers over-tighten boards to such an extent that damage could be occurring. When you need to use a foot-long or more arm on a wrench to untighten the bolt holding a delicate and multi-layer circuit board, I tend to feel they might just be over-tightening it a tad.

[Confused]

Oddly enough, even measured torqueing of screws and bolts is very inaccurate in terms of the actual load exerted and stress imposed in the bolt. What matters is the load / extension force on the bolt. As an example, a super lubricated bolt will impose many times the actual force compared a non lubricated bolt with a given identical torque load. To be honest, these are speaker bolts were are talking about here, so common sense and a careful touch and lots of feel are what is required and as good as anything. If you are known amongst your mates as 'Mr gorilla hands' or similar, maybe get someone else to do it!

[ogs]

Interesting.

I mean they weren't loose so to speak, just not tight. I could turn the bolts with practically no force so just carefully finger tightenened them further. They're only a 2.5mm allen bolt so I'm guessing not designed for huge force.

No idea whether PMC don't tighten much, or they'd loosened over time with the previous owner (who said they had very few hours as a demo pair).

Either way they sound much more like the pair I demoed.

The question now is - how tight should they be?! I don't want to overtighten.  For now they sound great so am leaving them. Have asked PMC but no reply so far.

Are you using the SAM profile?

[Antoine]

This is indeed a great tip to 'tighten' up things litterally and figuratively. But don't overdo it of course as the bolts/screws at a certain point will start to work as a drillbit...

If your speakers are on spikes it's good to also check every once in a while if the nuts tightening the spikes are also still secure. This'll have a similar effect on tightness. You'll want those drivers and loudspeakers to have maximum transmission of energy into the air their in and nothing else.

[Hifi_swlon]

Yeah, I was careful (I have torque wrench I use for my cycle, but it's not great at very low torque, so I use a light grip).

But like Rufus says, it's a shame they don't give a torque because it's going to be expensive to overdo it. (Plus I'd probably cry). But maybe it can be a tighter and sound even better

PMC seem to avoid answering, so I guess they do it by feel but don't want to say that....

They've been off their spikes for a few weeks as I had speakers on demo and it's too complicated moving them around with spikes on (and on granite blocks on wooden floor). Will sort that out next week hopefully.

[Hifi_swlon]

Are you using the SAM profile?

On and off. I'm running it now at around 10%. For a period I preferred without but I moved speakers around a lot a few weeks ago and once they were in their final (slightly adjusted) place, I kind of liked it on at a low level.

I'm hot and cold with SAM. Previously I would have been happy to disable it (and did). Now I like it low. In the early days I had it 70% or so. It seems really dependent on slight position changes in my room/setup and can sound worse on in some cases.