Go Back   Home > Forums > Live Sound > PA Systems

PA Systems A forum for discussion of all parts of a sound reinforcement or DJ system: loudspeakers, mixers (desks) etc.

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 27th September 2013, 07:19 PM   #1
diyAudio Member
 
chris661's Avatar
 
Join Date: Feb 2008
Location: Sheffield
Blog Entries: 8
Default PA subwoofer help please

Hi guys,

At a local shop, there's a single Tannoy T40 passive subwoofer on sale for 80. I'm rather tempted - it'll hit 40Hz with plenty of output, and is reasonably compact as subwoofers go.

My question is this: can it be bettered for similar money and size?

I think a 12" tapped horn might be a good shout, but I'm struggling to get them to pass 120dB in 2pi space, down to about 40-50Hz, and in a slightly bigger cabinet than the T40, which will go much louder.

This is to pair up with a pair of Das Audio RF12s - basic 12" two-ways, 98dB@1w, with half a kilowatt between them.

Advice and help would be much appreciated

TIA

Chris
  Reply With Quote
Old 28th September 2013, 07:47 PM   #2
diyAudio Member
 
Join Date: Mar 2006
Location: Montana Missoula
Hard for DIY to compete with used Pro-sound equipment. The little bits add up fast and then you have the issue of resale. That looks like a good deal Tannoy T40 Powerful Subwoofer
  Reply With Quote
Old 30th September 2013, 12:59 PM   #3
diyAudio Member
 
chris661's Avatar
 
Join Date: Feb 2008
Location: Sheffield
Blog Entries: 8
I know it was ex-club install, so its likely to have been thrashed a bit. I'll have a listen to it when I get there - no point having it if its knackered.

I'll take some pictures if I bring it home/open it up: I'm fairly sure its a 6th order bandpass, but I don't know much more than that.

I might fire up Hornresp and see if I can get anything useful in a similar form-factor.

Chris
  Reply With Quote
Old 30th September 2013, 02:07 PM   #4
diyAudio Member
 
Join Date: Mar 2006
Location: Montana Missoula
Bandpass boxes look good on paper but can sound funky and develop rattles with use. I would defiantly run it through some sweeps @ power.
  Reply With Quote
Old 1st October 2013, 02:20 PM   #5
diyAudio Member
 
chris661's Avatar
 
Join Date: Feb 2008
Location: Sheffield
Blog Entries: 8
Sounded nice enough to me, and no rattles.

That said, it has been painted a couple of times, so I might do something about that: probably starting by sanding it all smooth, and going over with a charcoal grey, and highlighting the ports in a neon green like some of DrDyna's subwoofer designs.

Pictures soon - its currently shoved in the corner of the lounge, as my PA system is now the house stereo.
Call it headroom, not overkill.

Chris
  Reply With Quote
Old 7th October 2013, 09:05 AM   #6
diyAudio Member
 
Join Date: Oct 2013
Location: Leicestershire
Mmmm. Caught this thread whilst searching for a Tannoy driver cross reference. You should have a 3803 in that one.
I was going to ask where it was, but you had already taken the wiser option and bought it.
80, brilliant price and they do go beautifully low......
Your best option for paint is Tuff Cab from Blue Aran. Roller it on thickly, and it creates a splatter coat effect, covering all smaller nicks & scratches.
  Reply With Quote
Old 9th October 2013, 10:49 AM   #7
diyAudio Member
 
chris661's Avatar
 
Join Date: Feb 2008
Location: Sheffield
Blog Entries: 8
Cheers for the paint recommendation.

I took the bottom off to clear out a load of glass from the bottom enclosure. Haven't taken the driver out the box yet, but I can confirm it has a cast frame.

99dB@1w half-space, with -3dB at 36Hz. I was very impressed with the specs they've managed to squeeze out of a single driver, and might well purchase another if one becomes available - they're the right size for a one-man lift without much trouble, but much bigger would get more difficult.

I'll be using it for a house party in the basement of an old thick-stone-walls type of house, later this month. Throw it in the corner and it should go >100dB@1w. High-pass at 30Hz and add a 300w amp. Lets see what this thing can do

Gotta run now, lectures in 10.

Chris

PS - if another comes up on eBay with delivery, let me know if you're going to bid so I won't bid against you.
  Reply With Quote
Old 9th October 2013, 12:30 PM   #8
diyAudio Member
 
Join Date: Oct 2013
Location: Leicestershire
Thanks for that offer, if you're going for a pair, I won't challenge you, so keep in touch in that respect, so I don't. Beware of buying one too new, because they changed the drivers 3803 is RCF L15P540. Not sure of the newer one, I think it's Celestion, but matched is better.
I've already got a pair, (Using with i8) I was just thinking, 80, and you didn't want it, a spare is always useful.
  Reply With Quote
Old 9th October 2013, 01:41 PM   #9
diyAudio Member
 
chris661's Avatar
 
Join Date: Feb 2008
Location: Sheffield
Blog Entries: 8
Yeah, I saw a pair that looked rather new go for 350/pr on eBay. More than I'd want to spend atm - I've only just paid back the Das Audio speakers and some rack stuff.

Pheeow. Just looked up the RCF driver and they're more than I paid for the cabinet!

How much power do you throw at your T40s?

Cheers
Chris

PS - had a quick play around in Hornresp. Looks like the Tannoy specs are pretty close to simulation, though I get ~96dB half-space, with a maximum corner-loaded SPL of ~130dB, within Xdamage, but beyond Xmax.

Last edited by chris661; 9th October 2013 at 01:51 PM.
  Reply With Quote
Old 27th October 2013, 05:23 PM   #10
diyAudio Member
 
chris661's Avatar
 
Join Date: Feb 2008
Location: Sheffield
Blog Entries: 8
Last night the Tannoy died.

It put up a decent fight, but in the end a Samson Servo-550 bridged put paid to it. The music was Pop music that was being mashed into the compressors, so there was an awful lot of power delivery there.

Some pictures of the post-mortem:

1 - no wonder the amp went into protection - not much will stand bridging into 1.7ohm
Click the image to open in full size.

2 - might be difficult to see, but the cone has seized slightly forward of its rest position.
Click the image to open in full size.

3 - dead voice-coil. Nuff said.
Click the image to open in full size.

I'll probably order another of these drivers, as that Tannoy sub is rather good: Sounds nice, hits the low 30s, and rather loud when corner-loaded.

... Unless there's anything out there that'll do better in a similar package?

Chris
  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
Best pa subwoofer. (Technically) H Burch PA Systems 42 10th October 2013 12:03 PM
Looking for subwoofer designs for PA use scameron78 Subwoofers 18 8th June 2011 03:24 AM
PA Subwoofer suchuwato Subwoofers 22 30th September 2008 03:48 PM
Newbie needs PA subwoofer advice poorbutproud Subwoofers 25 26th July 2002 03:31 PM


New To Site? Need Help?

All times are GMT. The time now is 02:13 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