How to make the best from an 8" sub - 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 25th March 2007, 10:49 PM   #1
diyAudio Member
 
Join Date: Mar 2007
Send a message via MSN to Denis.BR
Default How to make the best from an 8" sub

A friend of mine gave me a 8 inches subwoofer with a 9,5 liters box, made for small cars, and i'm using it here in my vintage, but the speakers have more bass than this little one.

The box is made of polyetilen (plastic), thats why is not so good.

What is the best way to use an 8" sub? vented? sealed? band pass? LT?

I don't really need it for powerful-ground shaking-soundsystem, just for a good quality system, and for fun, of course!

Here are the specs:

Power RMS: 120
Power PMPO: 240
Impedance: 4 ohms
SPL 1 W @ 1m (dB) : 86
Frew. Response. @ -10 dB (Hz) 40 to 2,5 k
Ressonace Freq.(Hz): 40
Magnet Weight: 620g
Coil Diameter: 38mm

Qms: 15,8
Qes: 0,65
Qts: 0,62
Vas: 20l
Sd: 0,022m
Vd: 77,9cm
Xmax: 3,5mm
Bl: 8,1 Tm
  Reply With Quote
Old 25th March 2007, 11:27 PM   #2
Speakerholic
diyAudio Moderator
 
Cal Weldon's Avatar
 
Join Date: Jan 2004
Location: Near Vancouver
Hi Denis,

I think you have a woofer rather than a sub so it might be hard to get a lot of extension. Down 10 dB at 40 Hz might need to be EQ'd. Have you thought about a box and a plate amp?
__________________
Next stop: Margaritaville
Some of Cal's stuff | Cal Weldon Consulting
  Reply With Quote
Old 25th March 2007, 11:45 PM   #3
diyAudio Member
 
Join Date: Mar 2007
Send a message via MSN to Denis.BR
good point!

but it is in mid term between a subwofer and a woofer, because it doesn't sound like a woofer and don't go to low frequencies, at least in this original box.

Click the image to open in full size.
  Reply With Quote
Old 27th March 2007, 03:15 PM   #4
OzMikeH is offline OzMikeH  Australia
diyAudio Member
 
Join Date: Mar 2007
If it has PMPO figure stated it probably isn't worth building a box for.
86db/w is pretty poor efficiency too. this means you need a much bigger amplifier for the same noise.
look for something that has a higher efficiency. worth spending a little more on a louder speaker than a lot more on a bigger amp.

I have experienced bass you can feel from a 1W amp with a 103dB/w speaker, this is an extreme case and you don't want to know what that driver cost. But Low power amps are a very good idea in a car, if you can get away with a 20W amplifier everything stays a lot cheaper (no voltage step up circuitry required for amplifiers)

You say a Vintage, I presume you are talking about a car?
Please excuse my rambling if I have missed the point.
  Reply With Quote
Old 27th March 2007, 04:11 PM   #5
diyAudio Member
 
Join Date: Mar 2007
Send a message via MSN to Denis.BR
OzMikeH, I got your point. I thought it would be good build a box just for fun, but if it will sound like the original box I'll leave it behind.

What I mean for vintage, is that I use an old 80's receiver in my bedroom plugged in my computer.

http://www.audiorama.com.br/gradient...m#MODEL%201200
  Reply With Quote
Old 27th March 2007, 04:24 PM   #6
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Hi,
that Qts tells you & the rest of us that the driver is not suitable for use in a vented box.
It is also above the sensible limit for use in a sealed box. If fitted to a sealed box it will need to be very big to keep the final Q below 0.9 and preferably below 0.8. Even those Qs are likely to be boomy (one note bass).
I think you could be talking about use in an open baffle, but the low Xmax would mean pretty low maximum output and that also rules out EQ as well, since it uses up enormous cone excursion to extend the bass lower.
Finally, forget Sub-bass, you are struggling just to get any bass out of it.
__________________
regards Andrew T.
  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
How can I add a "Digital In" to my current cd player ? (Make it work as a DAC ) b_online Digital Source 3 29th October 2014 02:37 AM
As James Brown (almost) used to say... "Make it Fonken...!" Dave the bass Full Range 191 21st June 2010 11:16 PM
Linear voltage regulator: how to make good use of "sense" and "ground sense"? NeoY2k Analog Line Level 7 7th September 2008 12:35 AM
Make Profit For "DIYAUDIO" Forum Pocoyo Everything Else 4 13th February 2007 07:14 PM
cheap 6" or 8" woofer to make great bass for a standard cab pick up zuki Subwoofers 12 15th February 2005 08:54 AM


New To Site? Need Help?

All times are GMT. The time now is 03:15 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