8" - 10" driver...looking for opinions... - 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 1st July 2012, 02:28 PM   #1
diyAudio Member
 
sideways's Avatar
 
Join Date: Feb 2007
Location: S'toon
Default 8" - 10" driver...looking for opinions...

Greetings!!

I am looking for a driver capable of hitting mid 30's cleanly that can go in a 20L sealed cabinet...ideas??

I've done a lot of reading on here but nothing conclusive has come out of it so I thought I would ask!!

Thanks kindly to all who respond...greatly appreciated!!
  Reply With Quote
Old 1st July 2012, 02:51 PM   #2
diyAudio Member
 
chlorofille's Avatar
 
Join Date: Jul 2008
Location: Malaysia
Try the Scanspeak 8'' sub. In a 20L closed box, F3 = 40Hz anechoic. In a typical room, the F3 would be at least in the mid 30's. Efficiency is terrible though.
  Reply With Quote
Old 1st July 2012, 03:14 PM   #3
diyAudio Member
 
chris661's Avatar
 
Join Date: Feb 2008
Location: Sheffield
Blog Entries: 8
Any driver can hit those frequencies in a sealed box. How loud it'll be is another thing entirely, but I will say this: unless the box is really really tiny, Xmax will become a problem first.

ESP - The Linkwitz Transform Circuit
  Reply With Quote
Old 1st July 2012, 04:58 PM   #4
diyAudio Member
 
sideways's Avatar
 
Join Date: Feb 2007
Location: S'toon
There was a couple of Tang Bangs and a Dayton that looked ok...possible???

As for efficiency...I never really listen loud but I do want presence at low volumes...again possible??
  Reply With Quote
Old 1st July 2012, 05:04 PM   #5
diyAudio Member
 
sideways's Avatar
 
Join Date: Feb 2007
Location: S'toon
Chris661...good read...thanks!!

So maybe I might have to go to a 12" or a 15"??

I do have a set of Eminence Beta 12CX's kicking around but I doubt they will get me that low in a sealed cabinet...

See...I want to incorporate something into a tower build...open baffle tweeter...possibly an open baffle midbass driver or seal that too...
  Reply With Quote
Old 1st July 2012, 06:09 PM   #6
diyAudio Member
 
Join Date: Feb 2008
Location: Jackson,michigan
here is a couple suggestions,

Recommended sub for PC to match pair of full range monitors.

Recommended sub for PC to match pair of full range monitors.

Or this one,

http://www.youtube.com/watch?v=Ca3ReyteqMs

What sub to build for small TV room?

FWIW

jer

Last edited by geraldfryjr; 1st July 2012 at 06:31 PM.
  Reply With Quote
Old 1st July 2012, 08:05 PM   #7
diyAudio Member
 
chris661's Avatar
 
Join Date: Feb 2008
Location: Sheffield
Blog Entries: 8
Quote:
Originally Posted by sideways View Post
Chris661...good read...thanks!!

So maybe I might have to go to a 12" or a 15"??

I do have a set of Eminence Beta 12CX's kicking around but I doubt they will get me that low in a sealed cabinet...

See...I want to incorporate something into a tower build...open baffle tweeter...possibly an open baffle midbass driver or seal that too...
It rather depends.

For a while, I used a pair of 8" drivers in a sealed cabinet, and added ~14dB boost to get to 28Hz.
They weren't particularly high quality drivers (the 3mm Xmax was a giveaway in hindsight), but at reasonable-to-quite-loud levels, went plenty low enough.

They fell down when it came to movies played at movie levels: they bottomed out several times during the Dark Knight.
IMHO, for a compact sealed subwoofer, don't try to eq below 40Hz. Below that, excursion and power requirements become silly. 35Hz with a low Q (~0.5) would be okay, but add an infrasonic filter to stop the cones flapping around.


The PA drivers you mention won't be of much use here...

PA drivers are designed primarily for high output, with limited low end. They use lightweight cones and short-throw motors (where almost all the coil is in the magnetic gap, no overhang: efficiency improves but Xmax is small).
Remember at this point that most PA systems consist of a woofer and a tweeter in a smallish ported cabinet, driven by an amplifier. Below port tuning, the woofers unload (there's nothing holding the cones still, so they're free to flap around), and the operator perceives this as running out of bass.
No problem: turn up the low end on a graphic eq, tone controls, whatever.
So now you have a speaker that's mechanically unloaded, with excess LF power being fed into it to make up for the cabinet rolloff.

Any HiFi speaker would give up at this point and the voice coil would start smacking into various other parts of the speaker. PA speakers don't: they employ suspensions that are very non-linear.
A linear suspension means low distortion (perfect for HiFi), but of course if the user isn't careful, you risk mechanical damage. That's alright though - most HiFi speakers aren't pushed near their limits.
So, these non-linear suspensions mean, once the excursion starts, there's also increasing amounts of distortion. This is of little consequence to most people listening to the PA system as the sound will remain more-or-less intelligible (some people like the added harmonics, but that's irrelevant). Point is you'll never bottom them out, which will badly screw up the sound (and the audience will notice).

Thing is, if your subwoofer suddenly starts adding lots of harmonics to the sound, it'll immediately draw attention to itself, which is the opposite of what you want: subwoofers shouldn't noticably add to the sound, but you should be able to tell if someone switches it off.
The harmonics would also mean you'd be able to locate the subwoofer in the room. If the subwoofer's between the front two speakers, not so bad. If it's off to one side somewhere, you've got a problem.


Okay, so you need a dedicated (sub) woofer. If you're using two of them, decent 8"s will probably suffice, but if the 10"s aren't much more expensive, I'd be inclined to go with those.

What's your budget?

Chris
  Reply With Quote
Old 1st July 2012, 11:18 PM   #8
diyAudio Member
 
sideways's Avatar
 
Join Date: Feb 2007
Location: S'toon
Hey Chris

So I guess I should mention...these are for music only...no movies...I just need them to be able to fill in a bit...

I'm running 2 Velodynes right now...mid 30's...fine enough but real estate dictates I need to scale down somewhat LOL!!!

So I figured if I could incorporate them into a tower build I would be a bit further ahead!!

Another thing...those subs are vented...what are the chances I could pull the drivers out and use them in a sealed cabinet??
  Reply With Quote
Old 2nd July 2012, 03:30 AM   #9
diyAudio Member
 
audiosteve's Avatar
 
Join Date: May 2004
Location: Niwot, CO
I built this a few years back and have been very happy with it. Its an 8" Tang band in a box slightly larger than you want, self powered and down 3db down around 33 Hz. Check out post #15. What can I do with this 8" TB sub without a 100 foot long port?. http://www.diyaudio.com/forums/galle...php/photo/4223
__________________
Nihilism is best done by professionals.

Last edited by audiosteve; 2nd July 2012 at 03:34 AM.
  Reply With Quote
Old 2nd July 2012, 10:38 AM   #10
diyAudio Member
 
chris661's Avatar
 
Join Date: Feb 2008
Location: Sheffield
Blog Entries: 8
Quote:
Originally Posted by sideways View Post
Hey Chris

So I guess I should mention...these are for music only...no movies...I just need them to be able to fill in a bit...

I'm running 2 Velodynes right now...mid 30's...fine enough but real estate dictates I need to scale down somewhat LOL!!!

So I figured if I could incorporate them into a tower build I would be a bit further ahead!!

Another thing...those subs are vented...what are the chances I could pull the drivers out and use them in a sealed cabinet??
If they're only needed to fill the sound out a little, 40Hz will be okay.

You could pull the drivers and put them in sealed cabinets. Ideally, you'd have the thiele-small parameters for them (perhaps you can get them measured?) so you can simulate and figure out the right specs for a Linkwitz Transform. You might find them okay without any LF boost, but there's no guarantee there. To get an idea of what you'll end up with, disconnect the internal amplifier, connect a different amplifier to the speaker (run the wire through the port) block up the ports (I use socks/scarves for this), and add something solid inside until the cabinet volume is ~20L. Have a listen. If you have some form of eq to hand (eg, Foobar2000), you could play with that until you're happy with the bass.

With some care, you could probably use the subwoofer plate amps too. Problem is that the manufacturer may have added eq in the plate amp for that driver in a ported box, so this would have to be bypassed or results would be unpredictable at best.

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
Opinions on pc/mobo "onboard spdif to Ian's FIFO kit" or "USB to WaveIO" to I2s? edbk PC Based 0 1st May 2012 03:40 PM
kinda ot... 10" x 10" x 10" aluminum block/bar, does such thing exist? Mickey Pass Labs 9 15th November 2011 09:22 PM
8" or 10" sub driver to go with computer speakers, music only, sealed cabinet. doors666 Subwoofers 9 25th November 2010 04:17 PM
Best Value 8",10" or 12" Driver cj.9 Subwoofers 15 8th December 2004 11:28 AM
HT: scale 10" sub cabinet for 12" driver? bbaker6212 Multi-Way 9 8th May 2003 07:54 PM


New To Site? Need Help?

All times are GMT. The time now is 04:56 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