DIY Monolith subwoofer

asdonk · 28-09-2005, 12:30 PM

today my MF300 and ASBF arrived and together with the new Peerless XXLS12 woofer I 'm going to build a Monolith subwoofer
the diference is that the subwoofer will have a sealed enclosure with a internal volume off 62 litres as advised by Peerless
the XXLS12 is developed out off the XLS range
I have the subwoofer already running as a prototype together with a BSBd200
subamp from BK with very good results

they make great amps those guys at BK

eviljohn2 · 28-09-2005, 6:35 PM

I demand pictures and more information.

If you get this beast working well it should slay almost all competition at any price up to about £2k I reckon.

asdonk · 28-09-2005, 6:57 PM

ofcourse it will , the shape off the enclosure is a pentagon, no not the one
in Washington, and has 40 mm panels
the first question what comes up is why filling the enclosure with damping material to make it look 10 % bigger , as the woofer sees it
first test with a cd full off test tones lets the sub go down to a 25 hz in room
fast and depp bass without any booming

sonic65 · 29-09-2005, 9:49 AM

The filling material should be of cellular form so air is present throughout the material.
The presence of this material slightly increases the effective volume as the sound wave is reduced in speed by passing through it. Therefore the time taken to reach the walls of the enclosure is longer and the box appears apparently larger.
I have just bought a BK BSBP 500watt plate amp and can say the quality is outstanding. I particularly like the switchable EQ and is currently set on +6dB. at 15Hz. Results on my Peerless XLS 12" indicate a really low bottom end. (Not measured it yet.) I am waiting for the Lab12 driver as used in the Monolith to become available (subject to satisfactory TS parameters.)

asdonk · 29-09-2005, 11:58 AM

some pitures on the dark side

http://img228.imageshack.us/img228/1...450x6006bg.jpg

http://img224.imageshack.us/img224/4...600x4505ql.jpg

Timbo21 · 29-09-2005, 12:37 PM

I love the pentagon, no parallel sides and all that

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I wish I knew enough about all this to do that

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Good luck to you

.

Let us know how much you're selling them for

T

**IronGiant** · 29-09-2005, 1:48 PM

I was expecting it to have 5 sides in total- ie a pentahedron

http://mathworld.wolfram.com/Pentahedron.html

Yours makes much more sense, very nice, what wood finish is it?

dave

asdonk · 29-09-2005, 2:33 PM

selling no way, I did get the pentagon enclosure for free
they are made off what we call in dutch waterrecistant multiplex
and it is 40 mm thick and 40 kg

Nimby · 29-09-2005, 9:35 PM

Very impressive construction!

We really ought to demand a response curve from you if you have an SPL meter.

Regards
Nimby

asdonk · 29-09-2005, 9:44 PM

I think Im will first buy a BFD to get the best results

MADMAND · 01-10-2005, 9:24 PM

Quote:

Originally Posted by sonic65

The filling material should be of cellular form so air is present throughout the material.
The presence of this material slightly increases the effective volume as the sound wave is reduced in speed by passing through it. Therefore the time taken to reach the walls of the enclosure is longer and the box appears apparently larger.
I have just bought a BK BSBP 500watt plate amp and can say the quality is outstanding. I particularly like the switchable EQ and is currently set on +6dB. at 15Hz. Results on my Peerless XLS 12" indicate a really low bottom end. (Not measured it yet.) I am waiting for the Lab12 driver as used in the Monolith to become available (subject to satisfactory TS parameters.)

BK are already selling the monolith LAB12 subwoofer in its unmodified state and have done for quite a while it is manufactured by EMINENCE. http://www.bkelec.com/Pro/Drive_Unit...ence/Lab12.htm

asdonk · 02-10-2005, 7:42 AM

looks good the LAB12 woofer but is it not that much different from the modified LAB 12 used in the Monolith subwoofer
the original Lab12 can be used in a 50 ltr sealed enclosure with good results
some bass boost at 20-25 hz might be needed

sonic65 · 02-10-2005, 10:48 AM

I am after the modified LAB12 mainly because it has a butyl rubber surround rather than the foam type. In the past my experience with foam surrounds on other makes of speakers has not been very successful, particularly in the longevity of the material. I hope to obtain the full Thiele-Small parameters from BK, although the free air resonance is easy enough to determine.

asdonk · 02-10-2005, 12:46 PM

I think the modified lab12 is hard to get
maybe specially made for BK, I also searched the web but cannot find any info
or datasheets

sonic65 · 02-10-2005, 1:29 PM

Yes the modified LAB12 is specially made and if not obtainable I will go for another XLS12 as this has a lower Fs than the XXLS12.

asdonk · 02-10-2005, 2:24 PM

what enclosure is the xls12 coming in, refle loaded or sealed

sonic65 · 02-10-2005, 6:35 PM

Designing a twin XLS12 or modified LAB12 reflex cabinet powered by the BK BSBP 500 plate amp but need the TS parameters first. I think your pentagon cabinet is quite something. How did you get those joints so accurate?

asdonk · 02-10-2005, 6:42 PM

these cabinets are build by a professional and I did get them for free
I have 2 off them and i am planning to build a second subwoofer to complete my second stereo set consisting off Focal Triga diy speakers

sonic65 · 02-10-2005, 6:51 PM

You should end up with quite a system, let us know your results!

asdonk · 05-10-2005, 9:13 AM

I am so pleased with the peerless xxls12 so i have plans to build a second
sub as i also have a second pentagon cabinet
the sub will be a peerless xxls12 type 830847 which comes into a 58 ltr basreflex volume, the F3 is 32 hz and with a little boost it wil rech 25 hz without a problem

asdonk · 06-10-2005, 10:31 AM

today ordered the peerless xxls12 woofer for the basreflex subwoofer
it was not at the store and had to be ordere
so I will first fix the enclosure