Another Peerless 830875 Execution

swin1 · 5th July 2009, 12:00 PM

Thought I'd post my latest creation:

http://www.ozphotolink.com/is.php?i=...g=SNV33488.JPG

http://www.ozphotolink.com/is.php?i=...g=SNV33489.JPG

A bit of background - built these over the Christmas holidays after arriving back from the UK. The tweeter is a Seas 27TFFC and the Woofer is a Peerless HDS 830875. Crossover uses bennic caps, standard 18guage air core inductors and 10w resistors. Picked up the drivers from another diyAudio member (thank you Chris) as I saw the opportunity to build a straight forward 2-way with a 7" driver. This is something I've wanted to do for a while but have been living around the world and didn't have easy access to work area or tools!

I was inspired by the idea of a traditional bookshelf (stand mount) design with good power handling using drivers with a smooth and easy rolloff, such as Zaph's SR71. In fact this design uses the same dimensions for the enclosure as the SR71 (Madisound's MD14) enclosure, but you save a little bit on the Peerless driver.

Cosmetically I used Victorian ash veneered 18mm MDF on all sides except for standard 25mm MDF baffle. The sides were chamfered front and back of the box, then copper coated along the edge. This is a good way of seemless mounting of the cut sides woofer which tends to look quite strange I think on uniform coloured baffles. I believe there needs to be something for those sides to line up with, anyone care to describe this in architectural terms?

The crossover is very simple, a design that gives the best power handling for this driver combination (which was my basic request to Madisound.) I am happy to post the LEAP output here:

http://2008.swinbank.fastmail.net/ro...erless2way.pdf

I have been absolutely thrilled by the results. I listen to lots of different kinds of music and what impresses me the most are the smooth bass response, voicing, imaging and handling of complicated passages such as hard rock. Initially I used an 0.82mh inductor on the woofer as this was what was locally available, and after noticing a slightly harsh sound, filled the air core with iron and measured the coil to spec, which flattened the filter out nicely.

Hopefully this gives some more idea's for others to work with!

Peace.

jerome69 · 5th July 2009, 12:05 PM

Hi,

Very nice project

Cheers.

Thebrain · 5th July 2009, 12:08 PM

oh! they are a thing of beauty

you should really not put speakers on hollow plastic boxes.
it will really mess up the bass clarity

swin1 · 6th July 2009, 02:34 AM

Ha ha, yeah I know it's a temporary solution while I rebuild the stands, they are taking a while as the base will be 40mm concrete!

I should remember to post pictures when everything is actually complete.

Amplifier is a modified AMI Jorgen from the 70's, gutted and replaced by LM1875T kit from chipamp.com with 120VA 18v toroid, dead silent!

Thebrain · 6th July 2009, 05:22 AM

Quote:

as the base will be 40mm concrete!

he he nice!

critofur · 22nd March 2010, 05:53 AM

Hey, could you post the pictures and .PDF again? The links have since died. I have the same drivers and may as well try it, since you like it so well

Ling Gowa · 22nd March 2010, 06:37 AM

links not working

swin1 · 23rd March 2010, 07:59 AM

hey guys, pm me your e-mails and I'll send you the details of the project with madisound LEAP crossover design.

critofur · 16th April 2010, 05:10 AM

Pictures as promised:

picowallspeaker · 16th April 2010, 05:16 AM

Nice stands ! Does the amplifier need a resonant chamber , either ?

And those things seem huge !! I just can't imagine how big is a floor tile...

5th July 2009, 12:00 PM	#1
swin1 diyAudio Member Join Date: Aug 2004 Location: ACT	Another Peerless 830875 Execution Thought I'd post my latest creation: http://www.ozphotolink.com/is.php?i=...g=SNV33488.JPG http://www.ozphotolink.com/is.php?i=...g=SNV33489.JPG A bit of background - built these over the Christmas holidays after arriving back from the UK. The tweeter is a Seas 27TFFC and the Woofer is a Peerless HDS 830875. Crossover uses bennic caps, standard 18guage air core inductors and 10w resistors. Picked up the drivers from another diyAudio member (thank you Chris) as I saw the opportunity to build a straight forward 2-way with a 7" driver. This is something I've wanted to do for a while but have been living around the world and didn't have easy access to work area or tools! I was inspired by the idea of a traditional bookshelf (stand mount) design with good power handling using drivers with a smooth and easy rolloff, such as Zaph's SR71. In fact this design uses the same dimensions for the enclosure as the SR71 (Madisound's MD14) enclosure, but you save a little bit on the Peerless driver. Cosmetically I used Victorian ash veneered 18mm MDF on all sides except for standard 25mm MDF baffle. The sides were chamfered front and back of the box, then copper coated along the edge. This is a good way of seemless mounting of the cut sides woofer which tends to look quite strange I think on uniform coloured baffles. I believe there needs to be something for those sides to line up with, anyone care to describe this in architectural terms? The crossover is very simple, a design that gives the best power handling for this driver combination (which was my basic request to Madisound.) I am happy to post the LEAP output here: http://2008.swinbank.fastmail.net/ro...erless2way.pdf I have been absolutely thrilled by the results. I listen to lots of different kinds of music and what impresses me the most are the smooth bass response, voicing, imaging and handling of complicated passages such as hard rock. Initially I used an 0.82mh inductor on the woofer as this was what was locally available, and after noticing a slightly harsh sound, filled the air core with iron and measured the coil to spec, which flattened the filter out nicely. Hopefully this gives some more idea's for others to work with! Peace.

22nd March 2010, 05:53 AM	#6
critofur diyAudio Member Join Date: Jan 2004 Location: Columbus, OH	Hey, could you post the pictures and .PDF again? The links have since died. I have the same drivers and may as well try it, since you like it so well __________________ Critofur http://www.ohmspeakers.com <- all the folks here are my friends

16th April 2010, 05:10 AM	#9
critofur diyAudio Member Join Date: Jan 2004 Location: Columbus, OH	Pictures as promised: __________________ Critofur http://www.ohmspeakers.com <- all the folks here are my friends

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5th July 2009, 12:05 PM	#2
jerome69 diyAudio Member Join Date: Feb 2008 Location: Lyon	Hi, Very nice project Cheers.

5th July 2009, 12:08 PM	#3
Thebrain diyAudio Member Join Date: Aug 2008 Location: Tel Aviv	oh! they are a thing of beauty you should really not put speakers on hollow plastic boxes. it will really mess up the bass clarity

6th July 2009, 02:34 AM	#4
swin1 diyAudio Member Join Date: Aug 2004 Location: ACT	Ha ha, yeah I know it's a temporary solution while I rebuild the stands, they are taking a while as the base will be 40mm concrete! I should remember to post pictures when everything is actually complete. Amplifier is a modified AMI Jorgen from the 70's, gutted and replaced by LM1875T kit from chipamp.com with 120VA 18v toroid, dead silent!

22nd March 2010, 06:37 AM	#7
Ling Gowa diyAudio Member Join Date: Aug 2009 Location: Barrie, Ontario	links not working

23rd March 2010, 07:59 AM	#8
swin1 diyAudio Member Join Date: Aug 2004 Location: ACT	hey guys, pm me your e-mails and I'll send you the details of the project with madisound LEAP crossover design.

16th April 2010, 05:16 AM	#10
picowallspeaker diyAudio Member Join Date: Apr 2007	Nice stands ! Does the amplifier need a resonant chamber , either ? And those things seem huge !! I just can't imagine how big is a floor tile...

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