KEF R400B or PV1D

DandyCobalt

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As my old subwoofer from my KEF eggs days seems to be on the way out, I'm looking to replace it . Budget £1,200, and aesthetics count for domestic acceptibility. (Used mainly for movies).

But I understand there is now a three-month wait for the B&W PV1D, which would be a natural choice to go with my B&W CM8s/1s etc.

Should I wait for the pv1d, or go for something like the KEF R400B?

I already have an Antimode s/w eq, so another thought was to get a second-hand older PV1 - but potentially no warranty etc could be a gamble.

Any thoughts most welcome.
 

Frank Harvey

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Like B&W's DB1, the PV1D and the R400 share the same basic design - dual force cancelling drivers. This reduces cabinet resonances, and gives you a cleaner bass than a normal box can manage. With a normal subwoofer, regardless of how well the cabinet is constructed or braced, the force from the driver pushes the cabinet back and forth. With dual driver, force cancelling arrangement, you not only double the air shifting capabilities, but the opposing drivers cancel out the forces produced by the other driver. It feels weird when you first touch a force cancelling sub, as you can hear all this low bass being churned out, but you can't detect any cabinet vibrations!

You should find the R400b will reach deeper as it has more cabinet volume, and the KEF uses dual 9" drivers instead of the PV1D's dual 8" drivers - you'll probably find that extra 1" isn't far off having another 8" driver on the PV1 in terms of area. I think your antimode will have less work to do with the R400b than your old sub, but it's worth making sure you're getting the best from it. You should find that because of the clean output from the R400b, it'll work well with the CM series.
 

DandyCobalt

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Hooray! Just picked up my new PV1D, after a long "out of stock" wait. Just in time for the weekend.

First thoughts to follow, once up and running..
 

Frank Harvey

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BenLaw said:
FrankHarveyHiFi said:
you'll probably find that extra 1" isn't far off having another 8" driver on the PV1 in terms of area.

Maths not your strong point then? Why give advice in fields you are not qualified? Why guess?

Do feel free to enlighten us with the correct answer. Extra marks will be given for showing the working out.
 

BenLaw

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FrankHarveyHiFi said:
BenLaw said:
FrankHarveyHiFi said:
you'll probably find that extra 1" isn't far off having another 8" driver on the PV1 in terms of area.

Maths not your strong point then? Why give advice in fields you are not qualified? Why guess?

Do feel free to enlighten us with the correct answer. Extra marks will be given for showing the working out.

You really don't know the formula for area of a circle? As I say, I'm staggered you would proffer advice on this basis when you don't have a clue.
 

The_Lhc

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BenLaw said:
FrankHarveyHiFi said:
BenLaw said:
FrankHarveyHiFi said:
you'll probably find that extra 1" isn't far off having another 8" driver on the PV1 in terms of area.

Maths not your strong point then? Why give advice in fields you are not qualified? Why guess?

Do feel free to enlighten us with the correct answer. Extra marks will be given for showing the working out.

You really don't know the formula for area of a circle? As I say, I'm staggered you would proffer advice on this basis when you don't have a clue.

Why should David have to behave any differently to any other member of the forum?
 

DandyCobalt

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BenLaw said:
FrankHarveyHiFi said:
BenLaw said:
FrankHarveyHiFi said:
you'll probably find that extra 1" isn't far off having another 8" driver on the PV1 in terms of area.

Maths not your strong point then? Why give advice in fields you are not qualified? Why guess?

Do feel free to enlighten us with the correct answer. Extra marks will be given for showing the working out.

You really don't know the formula for area of a circle? As I say, I'm staggered you would proffer advice on this basis when you don't have a clue.

Thank you both (by my rusty maths it's an extra approx 3" circle area) Looking forward to enjoying the music that comes out of whatever sized drivers are in it.
 

Frank Harvey

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In between doing everything I have to do (I won't list everything here), I've worked it out for the benefit of those anal enough to want exact details. I'm just checking my maths again though, as I'm a totally dumb ****.
 

BenLaw

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The_Lhc said:
BenLaw said:
FrankHarveyHiFi said:
BenLaw said:
FrankHarveyHiFi said:
you'll probably find that extra 1" isn't far off having another 8" driver on the PV1 in terms of area.

Maths not your strong point then? Why give advice in fields you are not qualified? Why guess?

Do feel free to enlighten us with the correct answer. Extra marks will be given for showing the working out.

You really don't know the formula for area of a circle? As I say, I'm staggered you would proffer advice on this basis when you don't have a clue.

Why should David have to behave any differently to any other member of the forum?

I feel there should be an additional degree of care taken by a dealer.

In this case, it was completely unnecessary to say, there was other content in his post. It's just marketing bollocks.
 

TheHomeCinemaCentre

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The_Lhc said:
BenLaw said:
FrankHarveyHiFi said:
BenLaw said:
FrankHarveyHiFi said:
you'll probably find that extra 1" isn't far off having another 8" driver on the PV1 in terms of area.

Maths not your strong point then? Why give advice in fields you are not qualified? Why guess?

Do feel free to enlighten us with the correct answer. Extra marks will be given for showing the working out.

You really don't know the formula for area of a circle? As I say, I'm staggered you would proffer advice on this basis when you don't have a clue.

Why should David have to behave any differently to any other member of the forum?

I like that!
 

BenLaw

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FrankHarveyHiFi said:
In between doing everything I have to do (I won't list everything here), I've worked it out for the benefit of those anal enough to want exact details. I'm just checking my maths again though, as I'm a totally dumb ****.

8 x 8 = 64

9 x 9 = 81.

Doesn't take much checking.
 

gregvet

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BenLaw said:
8 x 8 = 64

9 x 9 = 81.

Doesn't take much checking.

Unless Im missing something, those calulations would only apply if the drivers in question were square. At least make sure you get it right if you are going to criticise other peopls maths :doh:
 

gregvet

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8x8 driver area = 50.3 square inches (to one decimal place)

9x9 driver area = 63.6 square inches (to one decimal place)

The difference is actually closest to the area given by a 4 inch diameter driver, just in case anyone is actually interested.

Time for more beer I think .....
 

BenLaw

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Oops, in my haste I did leave it with diameter figures rather than radius; I thought the pi could be taken as read. Rather a long way off double as David was suggesting.
 

Frank Harvey

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gregvet said:
BenLaw said:
8 x 8 = 64

9 x 9 = 81.

Doesn't take much checking.

Unless Im missing something, those calulations would only apply if the drivers in question were square. At least make sure you get it right if you are going to criticise other peopls maths :doh:

Thank you gregvet. I got busy after posting on here so couldn't make it back on. You do sometimes find that when people are trying to catch other people out, they do tend to make their own mistakes in the haste of it all...

Let's not forget as well that we are talking about the area of TWO drivers, not one. So the difference between the two going by gregvet's figures changes from 13.3 to 26.6, which is a tad over half of an 8" driver. So, my quote of "not far off" isn't as way off the mark as some were trying to make out...

:)
 

The_Lhc

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BenLaw said:
The_Lhc said:
BenLaw said:
FrankHarveyHiFi said:
BenLaw said:
FrankHarveyHiFi said:
you'll probably find that extra 1" isn't far off having another 8" driver on the PV1 in terms of area.

Maths not your strong point then? Why give advice in fields you are not qualified? Why guess?

Do feel free to enlighten us with the correct answer. Extra marks will be given for showing the working out.

You really don't know the formula for area of a circle? As I say, I'm staggered you would proffer advice on this basis when you don't have a clue.

Why should David have to behave any differently to any other member of the forum?

I feel there should be an additional degree of care taken by a dealer.

Why? He's not actually selling anything on here (sure he might make the odd sale due to being here but that's not the same thing), we're not paying him to come here and give advice. As far as I'm concerned the dealers here can often be the only people contributing who actually have any experience of what they're talking about. The forum would be infinitely* poorer without their presence.

*And don't bother doing the maths on that one either...
 

AlbaBrown

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surely all the maths is largely inconsequential if the product doesn't sound fantastic?

There are many great sounding products out there which measure quite poorly...
 

DandyCobalt

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Getting back to the really important stuff - how does the PV1D sound?

Well, I'm always a bit worried if you need a computer to help you set up a loudspeaker...and not compatible with a mac!

Anyway, I connected my Antimode subwoofer EQ in line through to the PV1D, and then let it rip with, and in bypass mode. (I had already done the Antimode set up with microphone in listening position.)

The PV1D certainly shifts some air, but, placed in the corner of my room, it was bursting one of my eardrums in one seating position, and almost silent in another.

Activating the Antimode, ie taking out of bypass, yep, now it was doing it's stuff - very musical and responsive to the bass coming through.

I was testing it with the blu-ray of Jeff Beck at Ronnie Scott's - the one with the 12 year old (or looks like it) bass player. Superb!

But for a £1,200 speaker, which many would have positioned in a far-from-ideal place (like mine in corner), why don't they include the gubbins from an Antimode, with remote microphone EQ?

My feeling is that a PV1 (without the digital stuff) in combination with an Antimode EQ would have been much more cost-effective, if they hadn't discontinued it many months ago.

Anyone else had experience like this? I really don't know what parts of the complicated digital stuff I can actually use in the PV1D. I have it connected (via the Antimode) to a Pioneer LX52 receiver. Am I missing the benefits somehow?
 

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