Top opinions for a pair of SB Acoustics SB29NRX75-6 10 Woofers - Page 2 - diyAudio
Go Back   Home > Forums > Loudspeakers > Multi-Way

Multi-Way Conventional loudspeakers with crossovers

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 10th June 2008, 11:39 PM   #11
frugal-phile(tm)
diyAudio Moderator
 
planet10's Avatar
 
Join Date: Oct 2001
Location: Victoria, BC, NA, Sol III
Blog Entries: 5
Quote:
Originally posted by tinitus
btw ... it seem theres a new model FR125 with different (better?)chassis
To meet RoHS the FR125S was moved to a new chassis. It has 4 legs instead of 6 and is more open. The new designation is FR125SR.

As Al Wooley has shown these can make an excellent mid-tweeter ... and they respond to a little care & attention as well

dave
__________________
community sites t-linespeakers.org, frugal-horn.com, frugal-phile.com ........ commercial site planet10-HiFi
p10-hifi forum here at diyA
  Reply With Quote
Old 5th August 2008, 06:48 PM   #12
diyAudio Member
 
Jimmy154's Avatar
 
Join Date: Jun 2002
Location: NH, USA
I have obtained my drivers:

Seas 27TDFC - http://www.madisound.com/catalog/pro...roducts_id=792

CSS WR125S - http://homepage.mac.com/tlinespeaker...asurements.pdf

SB Acoutics SB29NRX75-6 10" Woofer - http://www.madisound.com/catalog/pro...oducts_id=8303

I'm going to use an active computer controlled x-over. I would like to make the speaker 6-7 inches wide, but this means I would have to side mount the woofer. Or I could mount it at a 30 degree angle from the front of the woofer to the side panel. I would like to cross the mid to woofer around 300 Hz, but might be able to go as low as 200 Hz or lower, I don't know.

Is there any way to pull off a slim speaker with my driver choices?

I will make the 10" woofer sealed or ported. An optimum TL will be too large I think. If I can't make a slim speaker I think I might make a Avalon type clone. Might actually be better, now that I think about it, so kids don't knock it over. Although, I can always make the bottom wider with the slim speaker.
__________________
I give up lol
  Reply With Quote
Old 15th August 2008, 10:31 PM   #13
diyAudio Member
 
Jimmy154's Avatar
 
Join Date: Jun 2002
Location: NH, USA
Interesting note about the SB woofer:
The sensitivity is taken at 31.6 cm at 2.83 Volts and is advertised at 88 "2.83V/1m" when is should be 10 dB less, I think. Or more accurately: the graph should be down 10 dB at 1 meter. What a bunch of dirty birdies, lol.

Also the Madisound specs differ from SB website specs.

I gave up on the idea of making the SB woofer side mounted.

Almost forgot, here's the graph: http://www.sbacoustics.com/images/10_graph.jpg
__________________
I give up lol
  Reply With Quote
Old 15th August 2008, 10:39 PM   #14
breez is offline breez  Finland
diyAudio Member
 
Join Date: Jul 2004
Location: Finland
Probably the graph has been adjusted to show sensitivity at 1 meter even if measured nearer. 79dB/2.83V is ridiculous.
  Reply With Quote
Old 16th August 2008, 01:37 PM   #15
diyAudio Member
 
Jimmy154's Avatar
 
Join Date: Jun 2002
Location: NH, USA
Yeah, I briefly thought that. But then I thought about the Dayton RSS265HO-4 which in it's specs boasts a 87 dB 2.83 V/1m and in the pdf a 84 dB 1 W/m, which makes sense, but it's graph shows it at maybe 82 dB, although it doesn't note the mic distance or power input.

The Sb Acoustics SB34NRX75-6, I think is more like 79 db at 2.83 Volts at 1 meter or slightly under 2W per meter. At 1W per meter it looks like it could be 76 dB.

I could measure it, but it doesn't matter to my speaker design. Both the SB34NRX75-6 and the Dayton RSS265HO-4 look liek they are about 80 dB at 2.83 Volts or 2W per meter, if tested on the same type of baffle.
__________________
I give up lol
  Reply With Quote
Old 16th August 2008, 03:54 PM   #16
breez is offline breez  Finland
diyAudio Member
 
Join Date: Jul 2004
Location: Finland
I have the 6" SB Acoustics woofers (88-90dB in graph, mic at 31.6cm), but no SPL calibrated microphone. When I get my boxes, I'll have to see how great the difference in sensitivity is to Seas H1499 quoted at 92dB/2.83V/1m with graphs showing almost 95dB at high midrange. Luckily I'm going for a digital crossover so I don't have to deal with a possible 10dB+ difference in sensitivity
  Reply With Quote
Old 16th August 2008, 04:47 PM   #17
diyAudio Member
 
Jimmy154's Avatar
 
Join Date: Jun 2002
Location: NH, USA
I will also be using an active cross-over, but I thought the claimed SB SPL was worth mentioning. It's a 10 dB lie. That's a lot of dBs to lie about lol -- I do have to hand it to them though, they did mention the mic distance and Voltage and Baffle type in the SPL graph.

Also I wanted to know whether I should use these specs at madisound or SB Acoustics to build my speakers. But I don't think any one can say which QMS and QES is correct. I guess I will have to go with madisound specs or measure them myself

Madisound:

Mechanical Q-factor (Qms) 8.4
Electrical Q-factor (Qes) 0.37
Total Q-factor (Qts) 0.36


SB website:

Mechanical Q-factor (Qms) 5.7
Electrical Q-factor (Qes) 0.38
Total Q-factor (Qts) 0.35
__________________
I give up lol
  Reply With Quote
Old 16th August 2008, 05:16 PM   #18
breez is offline breez  Finland
diyAudio Member
 
Join Date: Jul 2004
Location: Finland
The difference in paramters seems pretty minor. I'm not familiar with TL, all I know at this point that vented enclosures are much more sensitive to differences in T/S parameters than closed enclosures. Try modeling with both and see if the difference is anything to worry about?
  Reply With Quote
Old 17th August 2008, 03:37 PM   #19
diyAudio Member
 
Jimmy154's Avatar
 
Join Date: Jun 2002
Location: NH, USA
I modeled both the parameters madisound's and SB's in dosbox. Not much difference according to the dosbox, especially for a tl as you (breez) stated.

I decided on a TL of 600 cm^2 cross-sectional area and 2 meters long. Dosbox does not have an input value for the distance of the woofer from the starting point of the line (28 cm I'm thinking). Is this really significant? I used to use MJK's worksheets to model some tls and they had some sort of driver position value. I don't notice much of a difference in response when changing the driver distance from the start of the line.

I will be using http://kxproject.lugosoft.com/ as the software (and firmware?) for the cross-over hopefully.

I guess I will make the midrange sealed. I also thought of making some type of resonance killing enclosure (variant of a tl?) for the mid, but I guess there is no room. I think I might try to draw this enclosure in Autocad before I make it. That might fill me with rage though
__________________
I give up lol
  Reply With Quote
Old 22nd August 2008, 12:41 AM   #20
diyAudio Member
 
Jimmy154's Avatar
 
Join Date: Jun 2002
Location: NH, USA
How small can I make the enclosure for the WR125S high passed at around 300 Hz at 12 or 24 db, without hurting the sound quality?

I realize this is a moronic question. But I think it can be very small since I am high passing it at 300 Hz, 200 at the lowest. I don't think the Q of the box should matter too much.
__________________
I give up lol
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
SB Acoustics 10" woofers Jimmy154 Swap Meet 15 4th May 2011 09:23 AM
FS: 2 - SB Acoustics 10" SB29NRX75-6 Jimmy154 Swap Meet 3 10th July 2009 08:30 PM
Pair AE Acoustics TD10X woofers audiokinesis Swap Meet 5 13th February 2009 02:00 PM
Davis acoustics opinions/thoughts RyanC Multi-Way 1 24th May 2005 07:53 PM
Pair Vintage Micro Acoustics 10" Woofers/speakers !!!!! dale cooper Swap Meet 0 13th April 2005 12:22 AM


New To Site? Need Help?

All times are GMT. The time now is 06:41 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2