Harbeth Monitor 40.1 specific

[A.S.]

I found a picture on the internet which shows a generalised situation concerning the low frequency response of most speaker systems, sealed or vented. This is not at all specific to the Monitor 40 or M40.1 (all details are different) but it shows the general idea of the designer's options.

Note that there are a number of frequency response (sound pressure) curves that have been overlaid. Each one represents a choice for the designer who will eventually optimise the speaker system to behave as one and only one curve. Note that all curves pass through a point which I call the 'pivot point' at, in this generic example, 60Hz. You can see that if the designer wants some more output above the pivot point this can achieved done but the trade-off is that there will be less output below that point. In other words, he can trade extension for output around the pivot frequency.

Although the designer will fix the parameters of the bass unit unit and/or enclosure to whatever his marketing dept. tell him is the low end sound needed by the customer, if the box is vented (ported) the user does have a small ability to swing the changes around the pivot frequency. He can stuff the port(s) with socks or similar which will have the effect of reducing output above pivot frequency and increasing below ..... but he will reduce power handling and he will probably change the sonic quality in the middle frequencies as the box can no longer 'breath'.

The relevance of this discussion is how it relates to the M40 and M40.1. In general terms you could say that the M40 and M40.1 have approximately the same pivot frequency, and the M40.1 has been tipped in favour of extended bass, a lower Q, and hence more compatible with typical untreated domestic rooms. The original M40 was specifically designed to mimic the BBC LS5/8 and work in traditional BBC-style control rooms where the deep wall-lagging is tuned to suck-out lots of sound in the 50-100Hz region.

Hope that helps.

[chord]

A different question from the previous discussion.

What is the recommended stand height for 40.1? 14" or 17"? What stand height are most people using for M40?

[skylan]

Hi Chord,

The M 40.1 speakers were on 16" (41cm) stands at the CES show and performed wonderfully.
The original version mostly was placed on 20" stands, here in North America.

Noel Nolan.

[chord]

Hi Skylan,

It seems that Sound Anchors tailor make the stands for M40.1 at two heights: 14" and 17". What would the implication on sonic difference for stands of different heights be?

Would you recommend 14" or 17" yourself?

[Don Leman]

Hi Chord,

Noel "Skylan" Nolen is the manufacturer of Skylan who build highly regarded speaker stands specifically for each Harbeth model. HIs webpage is http://www.skylanstands.com/stands.htm

Don

[skylan]

Hi Charo,

If you are referring to the original M 40 speakers, they were placed on much taller stands to bring the cabinet higher off the floor and thin out the Bass. Some folks had them on 23" stands and were using room correction in the system also. (Remember this speaker was mostly used in recording studios where it was mounted higher from the floor to better accommodate the controller sitting behind the control desk).

However the new M 40.1 is redesigned to work way much better in domestic environments and can now be placed on shorter stands. (Also very much more room friendly in placement to wall boundaries).

So if you are using the original model, don't go below that 17" Sound Anchor stand model you refer to and most important if you are on hardwood floors as this will add to Bass reflection.

Noel.

[chord]

Appreciate for your response.

I am thinking of the stand heights appropriate for the new M40.1 as I am planning to get a pair

[chord]

Sorry to ask the question again. I have to come to a decision soon on the stand height, 14" or 17". The floor is of marble type. I reckon the bass reflection is even worse than hardwood floor?

Should 14" or 17" be more appropriate for M40.1?

[A.S.]

Unfortunately, this question can not be reliably answered by other users. You have to do some basic research yourself, with the help of an assistant.

The stand height that suits me (I am 1.84m tall) when sitting upright on my couch, without small children or animals to worry about and free from cosmetic considerations may not suit you at all. It would probably be too tall for you. But if you are taller than me, and you sit in an office chair then you would probably pick a taller stand than me - or if you are shorter, and you prefer to curl up on a bean bag on the floor, you'd probably select a shorter stand. There are so many factors to consider. What I would do is this to gather some basic data: sit in your normal seat, in your normal posture and ask your assistant to measure how far your ears are above the floor in centimetres. Let's call that number (E). The M40.1s tweeter is 66 cms. above the bottom of the cabinet, as it would sit on the top surface of the stand. Let's call that number (T). Be careful not to mix up inches and cms.

Now we do a simple subtraction: we take away the M40.1 cabinet bottom to tweeter height (T) from the height of your ears above the floor (E) and we have the theoretically optimum stand height. The maths is ....

(E) - (T) = (S) where (S) is stand height in cms.

Divide (S) by 2.54 and you have the stand height in inches.

NOTE: This is the theoretical height which will put the M40.1 tweeter level with your ears. It is a starting guide only. You must consider all factors such as the presence of children before you finalise this. Of course, if the stand has a tilt function, then you can reconsider the situation by tilting the speaker rather than just increasing/decreasing stand height to put the tweeter level with your ears.

Noel (Skylan) says that his stands at the CES/Harbeth room were 16" (about 41cms). The couch-seat was very soft and I sank down into the cushions. This placed my ears a little below tweeter axis.

As for the floor of hardwood or marble I don't think it would make any difference to the sound waves. Turn down the lights in your room. Sitting in your hot spot, hold a torch up by your ear and point it to a point on the hard floor somewhere between you and the speakers. You will find a reflection from the floor onto the speaker's bass unit. That's the place on the floor to put your rug or other absorber for maximum effect.

[chord]

Thanks Alan for the more quantitative guide on stand height.

In plain, it is the principle that the ear level is ideally at the same height level as the tweeter of M40.1 on the stand and, it is dependent on what I sit on. Also, in your previous posts in M40 thread, you once mentioned M40.1 is not fussy about stand height as long as it is between 12" - 20".

Btw, my height is no less or no more than yours.

[A.S.]

Well 12-20" is a significant range. That would be a very extreme situation and will not give me great results at either end of that range. But again, it critically depends upon you - your height, chair etc.

I guess - and this is only a guess - that for moderately tall people like you/me with soft modern chairs probably a good stand height is in the range 14-18". But you really should make some basic measurement to confirm or not my guess.

[A.S.]

Here is a picture of two great stand designers. Holding the M40.1 in his arms is Noel from Skylan. Skylan stands are of lightweight construction, and as shown here at the 2008 CES show, fitted with Tim Ryan's 'kilt' to match the grille cloth of the M40.1 itself.

As you can see, Noel's stands are more than capable of taking his weight plus the M40.1!

>

[Hu]

Oh, could you hold your M40-1 like that, Alan?

[DSRANCE]

I rarely look there, but had a peek on the Naim forum (strange as I sold their ranges for twenty five years...). There's a thread concerning someone who heard the 40.1 driven by a Townshend source and a SIX PACK (6x power amps) Naim system with multiple power supplies etc.. he was nearly beside himself with delight and glee... (I nearly said something else but thought to spare your blushes...... ;) )

I'm getting rather excited at the prospect of hearing them myself.......

[Gan CK]

I rarely look there, but had a peek on the Naim forum (strange as I sold their ranges for twenty five years...). There's a thread concerning someone who heard the 40.1 driven by a Townshend source and a SIX PACK (6x power amps) Naim system with multiple power supplies etc.. he was nearly beside himself with delight and glee... (I nearly said something else but thought to spare your blushes...... ;) )

I'm getting rather excited at the prospect of hearing them myself.......

Wow, i'd love to listen to this setup man! Must be in the goosebumps territory.

[A.S.]

Could someone provide me with the link so we can have a look at this story before publishing here please? Thank you.

[Soundbyte]

http://forums.naim-audio.com/eve/for...5/m/3512984217

Here you go...

[Don Leman]

Alan, could you confirm how many speaker binding posts are on the new Monitor 40.1. From this picture it would seem only two. If this is how the production version is set up one wonders how it could be driven by a SIX PACK.

http://harbeth.co.uk/usergroup/attac...5&d=1197151654

Don
West Coast Audio

[A.S.]

Hello Don,

I've made some enquiries following your message as to the whereabouts of the (only) pair of M40.1 that is in the USA during this past week. I conclude that the comment on the NAIM link is in fact a reference to a user who has listened to and is commenting on the Monitor 40, not Monitor 40.1.

You are absolutely correct that the production Monitor 40.1 has one single pair of binding posts, not the three pairs of the original Monitor 40. This reflects the fact that the M40.1 is significantly easier to drive and requires much more modest amplification. In fact, at the THE/CES 2008 show, we used throughout the excellent DNM power amp, rated at 23+2W (I believe) which filled our busy room with sweet sound. So, as for 6 monoblocks hinted at in the NAIM posting - completely unnecessary - but clean power in careful hands is always thrilling!

[DSRANCE]

They'll be getting their Nait integrateds ready then.......

Seriously, I hope the 40.1 proves to be at least as successful as the previous one. There's "something" about good big bass units (to put it crudely) - this sense of ease, especially at low volume levels (ok Alan, I know the smaller Harbeth models do this too, but I think you know where I'm coming from...lol).