B&W 800 series midrange torque

[EmilSA]

Hello all, I wish to find out what the suggestions are in terms of the torque required when adjusting the screw at the back of the midrange driver on B&W 800 series speakers.

There is very little in my manuals about this topic, but I have been told that these need to be tightened after transportation. The question here is what is the correct torque measurement?

Hope somebody knows more about this!

[Pio]

Hello all, I wish to find out what the suggestions are in terms of the torque required when adjusting the screw at the back of the midrange driver on B&W 800 series speakers.

There is very little in my manuals about this topic, but I have been told that these need to be tightened after transportation. The question here is what is the correct torque measurement?

Hope somebody knows more about this!

My N802, 802D and 802D2 all came with a small disc and screw that fit in the back of the marlan head for transporting. I've always used a small amount of pressure by hand to tighten the back of the midrange and also the tweeters tube. Honestly, can't remember doing it on the new ones. Anyways, careful about going overboard with tightening the back of the tubes, the manual really doesnt say you need to (unless I totally missed the part that says you do).

[Weetabix]

Ensure the large screw is tightened to just over finger-tight to ensure it is returned to correct tension.

Turn it with either your fingers or a screw-driver until it starts to feel a little bit of friction, then, turn it just that little bit more, such as an eighth to quarter of a turn more, just to provide that slight tightness - this will ensure the mid-range driver is "free-floating" and seated home correctly.

regards

[leo2498]

hi EmilSA, who told you that you need to do that? few month ago I bought my 804D and I don't did it; it's my first diamond speaker and the dealer never say any info like that, thanks for your answer.

[JürgenW]

From an older Q&A by B&W I copied the following:

'There is a large aluminium slotted screw at the back of my speaker, behind the FST midrange. What is it for and should I adjust it?

Apart from in the CM6, our FST midrange unit has an unusual mounting arrangement. The driver is mechanically isolated from its enclosure, whether it is the sphere / tube "head" or a more conventional cabinet, by flexible gel components in the fixing arrangement. To optimise the isolation, a single securing rod is used that runs from the back of the driver to the back of the enclosure. The tension on the rod is controlled by the large head straight slot screw at the back of the enclosure, and this in turn controls the pressure on the flexible gel parts. In order to prevent excessive movement of the driver under impact in transit, a clamping disc is fitted over the screw head, held in place by a cross head screw in the centre. On installation, this clamping disc and centre screw are removed in accordance with the pictorial instructions on the label fitted to the assembly.

It is important that the tension on the rod is set correctly. It is preset at the factory and should not require adjustment, except if the driver has to be removed for one reason or another, but sometimes it may get altered by mistake. This may be because one's natural instinct is to have a fiddle to see what happens, but occasionally removing the transit clamping disc has been known to loosen the main screw if it has bound itself in the thread.

If either of these has happened, refer to your local B&W dealer to have the tension reset correctly. We recommend that you do not attempt this yourself.

[mjb]

From an older Q&A by B&W I copied the following:
'refer to your local B&W dealer to have the tension reset correctly. We recommend that you do not attempt this yourself.

Kind of leaves you hanging, doesn't it. I think its set about finger tight plus a quarter turn, using a small coin as a screw driver. I've never seen any torque settings, but I stand to be corrected.

[EmilSA]

I think finger tight about does the trick. The transport screw did loosen my main screw when I took it out originally. So I had to ask. Unfortunately B&W local agents don't want to get back to me, so I guess that's the end of the story then. Thanks!

[Rod#S]

Something that I have always wondered, why is it that the towers have this design but the HTM2, with the same midrange does not?

[Kal Rubinson]

Something that I have always wondered, why is it that the towers have this design but the HTM2, with the same midrange does not?

You need to look at the HTM1D now, sadly, discontinued. My solution is to use an 800Diamond for the center.

[Kal Rubinson]

I think finger tight about does the trick. The transport screw did loosen my main screw when I took it out originally. So I had to ask. Unfortunately B&W local agents don't want to get back to me, so I guess that's the end of the story then. Thanks!

Well, my L/R 800Di were set up by B&W while the center one arrived later. I found that the L/R were, in fact, set with the screw finger-tight but the center arrived a bit looser. I adjusted it to match. No magic involved. Still, a custom torque wrench would be a reassuring accessory.

[Rod#S]

You need to look at the HTM1D now, sadly, discontinued. My solution is to use an 800Diamond for the center.

Yeah the old HTM1D did have it but it also had the marlan head and the two seem to go hand in hand however both the 804 and 803 have it which leaves me scratching my head why the HTM2 doesn't. It's not like it's a feature of the more expensive speakers because the HTM2 is more than a single 804 and the same price as a single 803. The HTM2 has two ports behind the bass drivers and the terminals are centered behind the midrange but those could have been lowered to accomodate the screw.

[PewterTA]

I just got my 802 Diamonds and I listened to them yesterday for about 4 hours I'd say and really am enjoying them. I remembered this thread and looked at mine. I ended up turning mine a half turn and HOLY CRAP! NIGHT and DAY difference to me...it's so focused and clear now compared to the sound stage being "all over the place." I did try another half turn and it went right back to all over the place. So I backed it off a half turn to a full 180 degree from where I had it... it's just to the point of me having to change my pants. I can't believe how much better (only about 5 or 6 hours now on them) they sound! You can DEFINITELY tell when you've got it just right. I'd do 1/4 turns while playing music you know and you'll find the "sweet spot!"

Hopefully that helps some people in the future! Ha ha... I'm probably the only idiot that is trying to tweek his speakers within the first 10 hours. LOL

But at least I definitely picked up on the difference!

EDIT:

Listened to it some more and felt the mid range was a little strained...so I did a 1/4 turn looser and found the MAGIC!

[EmilSA]

This has turned out to be an interesting discussion actually! Thanks for all the input so far. I must admit that I would have expected some sort of torque setting to have come out of the woodwork by now, but perhaps if is just like a musical instrument that you need to tune by ear in this case? I wonder what would happen if one were to try out a chromatic tuner while the speaker is reproducing destinct notes? I actually think the best time to fiddle with this is right out of the box - I think unscrewing the transport screw is probably the most obvious culprit in loosening the actual adjustment screw, thereafter perhaps transport itself. I like Kal's idea of the third 800D as a centre - that is really privileged! I will be auditioning two Valve Audio Black Widow monoblocks this weekend - made in my hometown in South Africa! 800W (8 Ohm) per channel hybrid power! I'm sure they will sound fantastic on the 800D's! Wish I could find a Stereophile review of these!

[EmilSA]

The Valve Audio Black Widow's are great! I actually decided to buy them after the audition. Another finding is Kimber Select 3033 makes a big difference to bass reproduction and I think it will become my new reference cable.