Peerless passive radiator models

[sploo]

Hi,

I was looking at the Peerless 10" passive radiator for sale at BK (http://www.bkelec.com/HiFi/Drive_Uni...ess/XLS10P.htm). It's the 265g version, which is apparently model number 830468.

The only 10" passive I can find on the tymphany website is this (http://www.tymphany.com/datasheet/printview.php?id=34). This one is 400g, and model number 830481.

I notice that the Fs and Qms values are the only differences. If you put the 265g version into BassBox Pro, and change the Mms figure from 265 to 400g, the newly calculated Fs and Qms figures match those for the 400g version.

Does this mean that the two models are effectively the same unit, and I could therefore buy the 265g version and just add 135g?

[sreten]

Hi,

according to the blurb the moving parts are identical to the driver,
which means same Vas, actual mass without added weight =135g.

So the short answer is yes you can.

/sreten.

[Cal Weldon]

DACALL,

We prefer you to advertise in the trading post. Please re-post your passives there.

Thank you.

[sploo]

Originally posted by sreten
So the short answer is yes you can.

That's great news, thanks sreten.

I note that the Peerless app note uses a 400g model, and adds 200g to make 600g. I guess I can then just add 335g to the 265g model?

[kelticwizard]

Sploo:

Just curious, which driver are you using with this 10 Passive Radiator?

Reason I ask is that if it is a really long throw job like a Peerless sub, the conventional thing to do is to buy two PR's and mount them on the sides. That way, on big bass notes, their motion balances out and your enclosure won't move.

With one Passive Radiator, the enclosure can sometimes move.


Then there is also the issue that in some alignments, the single Passive Radiator does not have enough excursion and therefore limits the bass output on lowest and loudest notes.

I know that Peerless Passive Radiators tend to be pricey, unfortunately.

[sploo]

Hi kelticwizard,

I was planning on using the XLS10 driver (830452).

I have seen a few posts mentioning the idea of using two passives, or a larger passive than the woofer. However, the app note on tymphany's website (http://www.tymphany.com/papers/appxls2.htm) details the use of a single passive, with 600g Mms.

I was considering reproducing this, though I want to put the driver and passive on opposite faces of the box. Most of the designs I've seen have them on adjacent faces (i.e. sub pointing towards you, passive towards the floor).

I don't know if there are any particular reasons why you shouldn't have them on opposite ends of a box?

[sreten]

Originally posted by sploo
Hi kelticwizard,

I was planning on using the XLS10 driver (830452).

I have seen a few posts mentioning the idea of using two passives, or a larger passive than the woofer. However, the app note on tymphany's website (http://www.tymphany.com/papers/appxls2.htm) details the use of a single passive, with 600g Mms.

I was considering reproducing this, though I want to put the driver and passive on opposite faces of the box. Most of the designs I've seen have them on adjacent faces (i.e. sub pointing towards you, passive towards the floor).

I don't know if there are any particular reasons why you shouldn't have them on opposite ends of a box?

Hi,

The application note is accurate about the use of one or two PR's.
Detuning (adding mass) to the PR to get the correct power handling
balance between driver and PR is IMO the way to do it for most cases.

For this PR though I would not recommend putting it at the
bottom. Putting the driver at the bottom and PR on the front
is far more sensible in terms of sag due to cone mass.

Opposite faces ? Fine except for top and bottom - sag issues.

Heavy PR's on the bottom should be built for the job.
Drivers on the bottom generally will have much less sag.

Also note the Peerless number are for a 20L box - compact.
In a different box size optimum mass will be different.


/sreten.

[sploo]

Thanks sreten,

I'm planning on having the driver on the front face and the passive on the rear.

Box size would probably be around 30l.

[sreten]

Hi,

have a read of this page :

http://www.hardwareanalysis.com/cont...nch_subwoofer/

I think is says in a bigger box you need less juice to hit the limits.

/sreten.

[sploo]

Thanks sreten - I'd already found that page, and it was partly that article that pushed me towards going for a 30l box.

Right now, I've just got to find a place where I can buy the passives! BK are on their annual hols, and tell me they don't have stocks of the 265g version. Wilmslow don't list them (but would probably charge a fortune anyway).

Anyone know where I can get the 265 or 400g versions in the UK?