musical subwoofer for Usher 2 ways - diyAudio
Go Back   Home > Forums > Loudspeakers > Subwoofers

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 7th March 2007, 11:43 PM   #1
qguy is offline qguy  Canada
diyAudio Member
 
Join Date: Mar 2005
Location: Burnaby
Send a message via AIM to qguy Send a message via MSN to qguy Send a message via Yahoo to qguy
Default musical subwoofer for Usher 2 ways

I currently have an Usher 2 way with the 8945 woofers and 9950 tweeters


The Plan

The plan is to make 2 boxes with two Usher 8955 in each box. These would serve as stands for the bookshelves. ala Wilson watt /Puppy config. . The Usher 8955 came to mind as this would be the closest matching driver to my current woofer and being similar in size and construction wont lag behind the 8945 mid/woofer. I plan to operate the sub from 25 to about 40 HZ

any thoughts on this ?
__________________
na
  Reply With Quote
Old 8th March 2007, 04:37 AM   #2
Ap is offline Ap
diyAudio Member
 
Ap's Avatar
 
Join Date: May 2002
Location: Sydney, Australia
Thats more of a bass driver than a sub driver - how far up do you intend on using them? If its beyond 100hz then stick with them, if it is for sub duty only (20-50hz) then I would pick the Dayton RS 10 or 12" - you could go side-fired if you want to keep cabinet wodth down.
  Reply With Quote
Old 8th March 2007, 03:13 PM   #3
bjorno is offline bjorno  Sweden
diyAudio Member
 
Join Date: Mar 2005
Location: Jacobsmountain
Send a message via MSN to bjorno
Hi guy,
Iíve designed a lot of similar systems with the corresponding Scan Speak elements and think if I had used the Usherís, they would have very similar performances and qualities.

Youíve made a very good choice to extend the 8945ís as you seem to aiming at a very low distortion system, but are you aware of the seize that this would mean if designing for 25 Hz?

Do you have T/S data for the specific 8955ís you have or will buy? What about the sub-amp specifications you surely need for crossing over at 40 Hz.

The ability to interface without adding artefacts from the definition of the low-end side to will be crucial for this application i.e. the sub amp, in this case, bandwidth definition must reach very low frequencies and without any low end filtering higher than first order and about 10 Hz.

For me its look like you are trying to crossover a ported 8945 at 40 Hz without considering the very mess and footprint this would imply to the summation by destroying the possible low-end definition and fidelity.

Another way to circumvent this possible sonic disaster, is by choosing a cutover higher than 80 Hz, preferably at 100 or even higher, if a ported box, or close the mid-woofer ports and eventually adjust the volume to suit a transfer function that integrates smoothly with the sub amp LP filter and so on.

b
  Reply With Quote
Old 8th March 2007, 09:01 PM   #4
Ap is offline Ap
diyAudio Member
 
Ap's Avatar
 
Join Date: May 2002
Location: Sydney, Australia
Yes check the specs, for a box volume of 1.9cu.ft. you are looking at an F3 of 39hz - this driver will not do 25hz.
http://www.partsexpress.com/resource...s/sb_guide.cfm
  Reply With Quote
Old 8th March 2007, 09:30 PM   #5
qguy is offline qguy  Canada
diyAudio Member
 
Join Date: Mar 2005
Location: Burnaby
Send a message via AIM to qguy Send a message via MSN to qguy Send a message via Yahoo to qguy
The specs for the 8955 woofer is

Specifications: *Power handling: 80 watts RMS/90 watts max *VCdia: 1-5/8" *Le: .50 mH *Impedance: 8 ohms *Re: 5.7 ohms *Frequency range: 25-7,000 Hz *Fs: 25 Hz *SPL: 87 dB 2.83V/1m *Vas: 4.70 cu. ft. *Qms: 2.00 *Qes: .38 *Qts: .32 *Xmax: 6.0mm

I was thinking of a woofer stand that would be 24 tall and about 9 inches across and X inches deep ?

How big a box do I need for one 8955 when going for 25 or say 30 hz ?
__________________
na
  Reply With Quote
Old 8th March 2007, 10:05 PM   #6
Ap is offline Ap
diyAudio Member
 
Ap's Avatar
 
Join Date: May 2002
Location: Sydney, Australia
Check the link to partsexpress gives you a quick idea of optimum volumes.
Otherwise if you model with WinISD (its free) I come up with 2.2cu. ft (thats 24hx9wx24d) tuned to 30hz, gives an f3 about 35hz - but efficiency is going tio be quite low - I doubt you can stretch this driver (or any 8") to much below 35hz.
  Reply With Quote
Old 9th March 2007, 03:23 AM   #7
Ap is offline Ap
diyAudio Member
 
Ap's Avatar
 
Join Date: May 2002
Location: Sydney, Australia
Thinking some more - if you are going for a single driver, then why not check out Aurum Cantus AC-250F1 10",
2.4cu.f t gets you down to 31hz plus it is 90db efficiency and 7ohms, plus a little cheaper than the usher too.
http://www.partsexpress.com/pe/showd...number=296-430
  Reply With Quote
Old 9th March 2007, 04:12 AM   #8
diyAudio Member
 
paulspencer's Avatar
 
Join Date: Sep 2003
Location: Melbourne, Australia
Right now I'd say you are in "no man's land" with what you have in mind. IMO best to stick to either:

1. subwoofer with a true sub driver with the upper bandwidth determined by placement and the performance of the driver (most subs perform poorly above 40 Hz)

2. stereo woofers crossing between 80 - 300 Hz with a lighter driver with smooth midrange, low inductance, a good linear motor and decent xmax

What you are doing is crossing low and operating in the range where a true sub driver will perform adequately and give you greater headroom and depth, yet you are using a woofer and in two boxes which could actually cross up higher very easily and improve the performance of your mains.

Some of the better subs can actually happily go up to 80 or even 100 Hz.

So, my suggestion is either make it a sub, or consider crossing your woofer higher. The simplest solution is run your mains full range and just add in a single sub.

As far as musical subs go, Rythmik Direct Servo is definately worth considering.
  Reply With Quote
Old 9th March 2007, 07:56 AM   #9
bjorno is offline bjorno  Sweden
diyAudio Member
 
Join Date: Mar 2005
Location: Jacobsmountain
Send a message via MSN to bjorno
Quote:
I was thinking of a woofer stand that would be 24 tall and about 9 inches across and X inches deep ?
Quote:
How big a box do I need for one 8955 when going for 25 or say 30 hz ?
qguy,

Between 63 to 83L seem right if you chose o build a MLTL/MLTQWT and I believe the 9Ē width (f-3dB 25 Hz) is not as good as 12Ē (f-3dB 25 Hz), which has a shorter port (less ringing).The Zalytron closeout sale is each for $ 80, maybe you can afford to build 4 speakers and gain about +6 dB?

b
Attached Images
File Type: gif u.gif (97.8 KB, 231 views)
  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
The New 2-ways. Spasticteapot Multi-Way 16 19th November 2006 12:39 AM
Two ways with a low x over tade Multi-Way 2 20th May 2006 06:22 PM
WTB 3 qty Usher T-9950 & Usher Qty 1 - 8845 markmelheim Swap Meet 1 17th May 2006 10:15 PM
Is a subwoofer needed for musical enjoyment?? dont argue folks(discussion) Andre Baptiste Subwoofers 52 19th March 2004 11:47 AM
small musical subwoofer? Dave Jones Subwoofers 8 20th September 2003 01:40 PM


New To Site? Need Help?

All times are GMT. The time now is 12:02 PM.


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