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#46 Re: Beyma CP21F match for Beyma TPL150H

Posted: Mon Dec 02, 2019 8:41 pm
by JohnG
The Drivers are at home now, so the first attempt at a Baffle can begin, I intend on using 18mm Buffalo Board, this is a compressed board, I assume it started out as 20+mm board. There are many off cuts of this material at my workplace.

I have the HiFi World Supplement, it is Number 19, put out in December 1995, it contains a Six Page Article on using the
Celestion SL-6000 as a Sub Woofer for a ESL 67. I can make a PDF of this if anybody would like to read up on the content.

There are a few ideas in my mind that are from another time and place, for instance I have always wanted to produce a additional Bass Section for the 57's, and I have been totally keen to produce a OB for a very long time, my break from HiFi put a stop to some of these wants.
Now I am immersed once more, I am trying to turn a few old ideas in a realisation.
If the idea of having a Bass Section for a OB and the Quads is not feasible when using the same parts, then the OB will take the priority, as this is my most important and most invested in speaker project.

As I get a acceptable Bass Note from the Quads, with the 845's driving them.
There is still room to play with the 57's, I have the option to stack, as I have two pairs, One pair is OTA refurbished with OTEC R Treble Panels, and One Pair are Quad Standard.
I can also try the DIY air filled Audax HD-P3 Piezzo Tweeters with the stacked pair, as I believe this is a easier integration for a driver. I can do these in Dipole on each channel, but I am not sure if any of this will have a beneficial effect.
I just really enjoy the Treble from these Piezzo's and good ol' curiosity crept in.
If a Bass unit was also achievable then I can see no reason not to have a go.

Most important, above all else, is to give the OB the best shot I can, and see how the 845's help them perform.

#47 Re: Beyma CP21F match for Beyma TPL150H

Posted: Mon Dec 02, 2019 8:41 pm
by JohnG
The Drivers are at home now, so the first attempt at a Baffle can begin, I intend on using 18mm Buffalo Board, this is a compressed board, I assume it started out as 20+mm board. There are many off cuts of this material at my workplace.

I have the HiFi World Supplement, it is Number 19, put out in December 1995, it contains a Six Page Article on using the
Celestion SL-6000 as a Sub Woofer for a ESL 67. I can make a PDF of this if anybody would like to read up on the content.

There are a few ideas in my mind that are from another time and place, for instance I have always wanted to produce a additional Bass Section for the 57's, and I have been totally keen to produce a OB for a very long time, my break from HiFi put a stop to some of these wants.
Now I am immersed once more, I am trying to turn a few old ideas in a realisation.
If the idea of having a Bass Section for a OB and the Quads is not feasible when using the same parts, then the OB will take the priority, as this is my most important and most invested in speaker project.

As I get a acceptable Bass Note from the Quads, with the 845's driving them.
There is still room to play with the 57's, I have the option to stack, as I have two pairs, One pair is OTA refurbished with OTEC R Treble Panels, and One Pair are Quad Standard.
I can also try the DIY air filled Audax HD-P3 Piezzo Tweeters with the stacked pair, as I believe this is a easier integration for a driver. I can do these in Dipole on each channel, but I am not sure if any of this will have a beneficial effect.
I just really enjoy the Treble from these Piezzo's and good ol' curiosity crept in.
If a Bass unit was also achievable then I can see no reason not to have a go.

Most important, above all else, is to give the OB the best shot I can, and see how the 845's help them perform.

#48 Re: Beyma CP21F match for Beyma TPL150H

Posted: Mon Dec 02, 2019 8:42 pm
by JohnG
The Drivers are at home now, so the first attempt at a Baffle can begin, I intend on using 18mm Buffalo Board, this is a compressed board, I assume it started out as 20+mm board. There are many off cuts of this material at my workplace.

I have the HiFi World Supplement, it is Number 19, put out in December 1995, it contains a Six Page Article on using the
Celestion SL-6000 as a Sub Woofer for a ESL 67. I can make a PDF of this if anybody would like to read up on the content.

There are a few ideas in my mind that are from another time and place, for instance I have always wanted to produce a additional Bass Section for the 57's, and I have been totally keen to produce a OB for a very long time, my break from HiFi put a stop to some of these wants.
Now I am immersed once more, I am trying to turn a few old ideas in a realisation.
If the idea of having a Bass Section for a OB and the Quads is not feasible when using the same parts, then the OB will take the priority, as this is my most important and most invested in speaker project.

As I get a acceptable Bass Note from the Quads, with the 845's driving them.
There is still room to play with the 57's, I have the option to stack, as I have two pairs, One pair is OTA refurbished with OTEC R Treble Panels, and One Pair are Quad Standard.
I can also try the DIY air filled Audax HD-P3 Piezzo Tweeters with the stacked pair, as I believe this is a easier integration for a driver. I can do these in Dipole on each channel, but I am not sure if any of this will have a beneficial effect.
I just really enjoy the Treble from these Piezzo's and good ol' curiosity crept in.
If a Bass unit was also achievable then I can see no reason not to have a go.

Most important, above all else, is to give the OB the best shot I can, and see how the 845's help them perform.

#49 Re: Beyma CP21F match for Beyma TPL150H

Posted: Tue Dec 03, 2019 12:04 pm
by Greg
Last time I looked, Celestion SL-6000 were no longer available.

#50 Re: Beyma CP21F match for Beyma TPL150H

Posted: Tue Dec 03, 2019 12:37 pm
by ed
this all maybe common knowledge...maybe not:

http://www.linkwitzlab.com/proto.htm

#51 Re: Beyma CP21F match for Beyma TPL150H

Posted: Tue Dec 03, 2019 1:37 pm
by steve s
I think John is planning on making his own version of the sl600 dipole bass unit .... if I've read him correctly of course !

#52 Re: Beyma CP21F match for Beyma TPL150H

Posted: Tue Dec 03, 2019 7:27 pm
by JohnG
I think that a Dipole, or Ripole Bass Set up with a Plate Amp, that will drive the Bass Units and also allow for a range of frequency adjustment, will be a type of design that can relate to the HiFi World DIY Supplement SL-6000 Sub Woofer.
I am not sure where they would be seen as different in their designs.
At the moment the Eminence Bass Section is on hold, I am going to work with the Beyma Drivers to get the feel for the work required.

As a initial baffle shape, I am planning on starting with a 500 - 600mm Width x 1200 - 1500mm Height x 18mm Depth Board.
I intend on starting with the TPL150 H's at ear level, and have the CP21F Just above the TPL and inset.
I can make a Straight Sided Oblong Baffle, or have the Sides tapering in towards the top of the baffle, maybe with the top being no wider than 200mm.
Any thoughts on the Baffle would be appreciated, I am thinking to start slightly oversized and trim the Baffle Dimensions if required.

#53 Re: Beyma CP21F match for Beyma TPL150H

Posted: Wed Dec 04, 2019 11:14 am
by ed
slightly familiar:
ob1.jpg

#54 Re: Beyma CP21F match for Beyma TPL150H

Posted: Wed Dec 04, 2019 1:05 pm
by JohnG
Good Find Ed.
It is as close to my proposal as I can imagine.
As I am going to have these OB's in a dedicated space, is there a need for a Baffle to conform to a certain area dimension,
or can the baffle be wider and higher to my proposed dimensions without being detrimental to sound quality.
This is a subject I am not sure I have ever looked into in any measure.

#55 Re: Beyma CP21F match for Beyma TPL150H

Posted: Wed Dec 04, 2019 1:25 pm
by Nick
Don't forget the benifit of having the bass driver close to the floor boundary.