Peerless XLS 12"

[The Dudster]

Hello.

I have purchased 4 x 12" XLS woofers as they were priced 40% off for a week at a retailer. Just had to buy them...:-)
Now, been reading about the Thor sub from the linkwitz page and like the idea of equalizing. Planning to buy a 2 x 900W/4 ohm Class D amp from this guy, http://www.cadaudio.dk/amplifierkits.htm.
Thinking about the TP0104. Should be enough power. Now, the question. What happens to the excursion etc if I would halve the speaker box volume from the recommended 47 litres to about 25 litres? The f3 will of course increase and thus the excursion will increase, but how much? Given that I have 4 woofers they may still be within their linear range...Just moved into a apartment complex, so have no idea what the neighbours will say.

BAF

[rabbitz]

I think the excursion would decrease below F3 and not increase.

Don't want to be your neighbour and I know what they'll say.

[Alcaid]

Download WinISD PRO from this page:
http://www.linearteam.dk/default.aspx?pageid=winisdpro
It's free and you can see the effect on cone excursion when changing box size. Easy to use, and I think they have the XLS 12" parameters in the database already.

[kjb]

Hey! I bought two. probobably from the same retailer. Good price indead.
now to my little warning...
I have read (can't remember where) that using XLS with a undersized closed box, it is possible that the rubber suspension will get sucked in and making a 'plopping' sound when the excursion is large.
So I would think twice befor I'll used them in a 25 l closed box.
but I might be wrong, I havn't tried it myself to confirm it.

[The Dudster]

Originally posted by Alcaid
Download WinISD PRO from this page:
http://www.linearteam.dk/default.aspx?pageid=winisdpro
It's free and you can see the effect on cone excursion when changing box size. Easy to use, and I think they have the XLS 12" parameters in the database already.

Downloaded it and it seems that the excursion drops for a given applied signal with a box of 25 litres as opposed 50 litres...Can't be rigth? Or is it that the aquostic output drops below f3 and thus the excursion? That must be it! Yes?

Oh yeah, you live in Stavanger? Small world, just moved into Sandnes...Hehe Cool, VERY small world indeed, gotta love the net.

BAF

[The Dudster]

Originally posted by kjb
Hey! I bought two. probobably from the same retailer. Good price indead.
now to my little warning...
I have read (can't remember where) that using XLS with a undersized closed box, it is possible that the rubber suspension will get sucked in and making a 'plopping' sound when the excursion is large.
So I would think twice befor I'll used them in a 25 l closed box.
but I might be wrong, I havn't tried it myself to confirm it.

Hmm, do you have this article? When the diapraghm moves out of the box, there is a relative underpressure inside the box. Is this enough to suck in the rubber surround? I really would like to see that article. Thanks for the pointer.

BAF

[kjb]

I found it! It was a message in a sweedish hifi/DIY forum.

http://www.hififorum.nu/forum/topic....=peerless,,XLS

read the message from 'jan' and it will explain. It is in danish. A bit hard to understand if you ar not from scandinavia I guess...

[The Dudster]

Hmm, read the article, speaking Norwegian, so Swedish is a breeze...Now, seems that the guy in the post had a guy working for Peerless over to his house. This guy mentioned that in the lab, Peerless had managed to create enough underpressure in the speaker box that the rubber surround was sucked in as the diapraghm moved out. Massive!!!

:-) Ok, guess i'll just replicate the Thor sub then, guess Siegfried Linkwitz knows what he is doing...:-)

Actually. I am very sure that he knows EXCACTLY what he is doing...

BAF

[ashok]

create enough underpressure in the speaker box that the rubber surround was sucked in as the diapraghm moved out.

This must have been in a very small box. In larger boxes this would be impossible to achieve. I am sure you cannot do this in boxes about 22liters. I know , we have built such a box.
Cheers.

[The Dudster]

Cool, did you use the Peerless 12" XLS? Was it equalized? How severe was the excursion? How many drivers did you use, I plan to use 4, 2 in 2 boxes of 50ish litres per box.

BAF