Celestion BN15 - 400S Neo speaker (8 ohm)

[alanbass1]

Is this a real bargain at £82 plus VAT and shipping or have they inflated their price?

[url="http://www.watfordvalves.com/product_detail.asp?id=3035"]http://www.watfordva...ail.asp?id=3035[/url]

Edited November 22, 2011 by alanbass1

[Moos3h]

+ vat

[alanbass1]

Looks like these are available at £104 incl VAT elsewhere

[Bill Fitzmaurice]

[quote name='alanbass1' timestamp='1321950384' post='1444621']
Is this a real bargain at £82
[/quote]Have you modeled it ? With only 2mm xmax I'm not sure it would be a 'bargain' at any price. The BL15-400 is infinitely better.

[Moos3h]

2mm Xmax? Isn't that practically useless then?

[Bill Fitzmaurice]

[quote name='Moos3h' timestamp='1321973822' post='1444975']
2mm Xmax? Isn't that practically useless then?
[/quote]If you want a highly compressed bottom thin tone or your only running 30 watts I guess it's OK. The BN15 400X is good at 4mm, though the .59 Qts of both it and the BL15 400 is a bit dodgy,

[Musky]

Don't Celestion use a different way of measuring Xmax to most other manufacturers? I seem to recall some discussion that multiplying by something like 1.7* gives a figure that could be compared directly to an Eminence driver for instance.

*Might be wildly wrong!

[Bill Fitzmaurice]

[quote name='Musky' timestamp='1322092861' post='1446558']
Don't Celestion use a different way of measuring Xmax to most other manufacturers? I seem to recall some discussion that multiplying by something like 1.7* gives a figure that could be compared directly to an Eminence driver for instance.

*Might be wildly wrong!
[/quote]Eminence use Klippel Analysis, which is more accurate than plate minus coil. But at best the Celestion figure might go up by 20% with a Klippel figure, so that 2mm might go up to 2.4mm.

[LawrenceH]

I have an old pair of Celestion K300 12s which only have a nominal 2mm xmax...they sound fab on bass and have sufficient grunt that we have on occasion used them with active crossovers as stand-in PA subwoofers, a job they've done just as well as any other compact reflex box I've heard. I'm sure they're technically distorting away but you have to drive them HARD to make them audibly fart out. For musical instrument speakers one could argue that xmech is a more important parameter, along with the behaviour of the speaker on exceeding xmax. But this is not straightforward to measure or model.

I don't think Celestion's designers are quite as clueless compared to the mighty Eminence as they seem to be made out to be in internetland - perhaps this comes partly from the very different relative costs of each in US versus UK. At £89, which was about what they used to be before prices went silly, they're pretty reasonably priced for a lightweight pressed steel 15" driver. £190 is clearly stupid and suggests Celestion may be effectively giving up on neo bass speakers for the time being other than for OEM replacements.

[muttley]

[quote name='Bill Fitzmaurice' timestamp='1322105918' post='1446597']
Eminence use Klippel Analysis, which is more accurate than plate minus coil. But at best the Celestion figure might go up by 20% with a Klippel figure, so that 2mm might go up to 2.4mm.
[/quote]

I'm pretty sure the Celestion figure is based on Herr Klippel's machine (I visited the R&D facility a couple of years ago).

[LawrenceH]

[quote name='muttley' timestamp='1322216416' post='1447967']
I'm pretty sure the Celestion figure is based on Herr Klippel's machine (I visited the R&D facility a couple of years ago).
[/quote]
According to their datasheets, quoted xmax is still using the arithmetic method. Be interested to know if they have Klippel figures as well though! Btw I don't think Bill's 20% increase rule of thumb is necessarily accurate, if you look at the B&C 10CL51 for example it has a quoted Xmax of 6mm (Klippel) but an arithmetic Xmax of ~4mm. For the 10NW64 it's 8 and 4 respectively. They also claim the 10% THD is ambiguous and prefer Xvar, based on physical behaviour of the driver rather than output signal. It's perhaps pertinent that although Eminence rule the roost in bass cabs, in high-end PA it's a different story.
For me, it just suggests that TS parameters are good for modelling small signal LF behaviour but to understand how a speaker performs at volume, easiest way is to build it!

[muttley]

Interesting. I had a look at the datasheet for the driver mentioned by the OP but didn't notice the definition of Xmax (basic arithmetic, Klippel, or otherwise).

[LawrenceH]

[quote name='muttley' timestamp='1322225912' post='1448190']
Interesting. I had a look at the datasheet for the driver mentioned by the OP but didn't notice the definition of Xmax (basic arithmetic, Klippel, or otherwise).
[/quote]
It's only defined on the datasheets for their 'pro' range PA drivers, but the voice coils and gap depths all strongly imply that they use the same calculation for their bass ones too. Interestingly, using the arithmetic method favoured by other manufacturers (Hvc - Hg)/2 + Hg/4 that particular driver clocks in at 4.5mm. Alex's very helpful Vd figures on his site suggests that for the Eminence drivers this value is close, but a bit optimistic compared to the distortion method, whereas the B&C drivers mostly meet or exceed it. Where these Celestions sit, who knows? But personally I'd choose this driver over the green labels for the midrange response, without losing any sleep over the xmax.