• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

DIY Subwoofer

jhaider

Major Contributor
Forum Donor
Joined
Jun 5, 2016
Messages
2,822
Likes
4,514
Actually once you know the trick its quite easy. You need to make one of these for your router out of a bit of ply.

View attachment 15456

View attachment 15457

That's a neat jig. It looks more intuitive to use than the commercial ones, such as the "Jasper Jig."

365-250_HR_0.jpg


However, the assumption is that one has a router to attach to the jig. That is a fairly specialized tool. If someone is not already a fairly avid woodworker, the assumption that one has a router sitting idle is unlikely to be true.
 

dalbert02

Member
Joined
Aug 14, 2018
Messages
20
Likes
14
Location
miami, fl
The Jasper Jig with a cheap harbor freight plunge router is perfect. I keep them permanently attached. The HF router isn't exactly a 'use every day' kinda router and I don't cut circles but maybe two dozen times a year. HF also has 20 to 25% off coupons rather frequently.
 
OP
F

FrantzM

Major Contributor
Forum Donor
Joined
Mar 12, 2016
Messages
4,337
Likes
7,730
Ok

From iPad...

The bucket subs work and rather well. They require a lot of power. At least 200 Watts. I will try to measure this weekend and post the measurements.
I have performed simple REW measurements and have eq accordingly. Sounds good but not enough SPL for my leaky (typical tropical construction with open windows) room.
Later
 
OP
F

FrantzM

Major Contributor
Forum Donor
Joined
Mar 12, 2016
Messages
4,337
Likes
7,730
Hi
I will ask for your kindness... I am a neophyte at this and am trying to learn on the fly .. With so much going in my business not much time to mess with things but the bucket subs work. This is the FR I got with 2 JBL LSR308 and the bucket-subs powered by a 100 wpc Rotel Amp... EQ via min DSP ....
FR in ROom with 2 BUSKET-SUBS.jpg


I am impressed I didn't believe it was going to be that good... It does sound like it though... MAX SPL @55 Hz is a low-ish 92 dB .. Am I reading this right or ???
 

RayDunzl

Grand Contributor
Central Scrutinizer
Joined
Mar 9, 2016
Messages
13,198
Likes
16,981
Location
Riverview FL
92dB maximum?

Have you tried to estimate their sensitivity? 2Vrms or 2.83Vpk signal - what SPL?
 

RayDunzl

Grand Contributor
Central Scrutinizer
Joined
Mar 9, 2016
Messages
13,198
Likes
16,981
Location
Riverview FL
Will try to figure out how

I would:

Take away the EQ and the 308s...

Put an A/C voltmeter on the speaker leads.

Play a tone with REW - 60Hz should not be inappropriate for a meter.

Adjust volume to produce 2Vrms or 2.83Vpeak - that's 1W at 8 Ohms, 2W at 4 Ohm

Perform SPL measure at various frequencies or sweep. Match the sweep level with the tone level in REW.
 
  • Like
Reactions: trl
OP
F

FrantzM

Major Contributor
Forum Donor
Joined
Mar 12, 2016
Messages
4,337
Likes
7,730
Not yet
Will try to figure out how
I would:

Take away the EQ and the 308s...

Put an A/C voltmeter on the speaker leads.

Play a tone with REW - 60Hz should not be inappropriate for a meter.

Adjust volume to produce 2Vrms or 2.83Vpeak - that's 1W at 8 Ohms, 2W at 4 Ohm

Perform SPL measure at various frequencies or sweep. Match the sweep level with the tone level in REW.
i will do it next week

Thanks Ray!
 

restorer-john

Grand Contributor
Joined
Mar 1, 2018
Messages
12,579
Likes
38,278
Location
Gold Coast, Queensland, Australia
Adjust volume to produce 2Vrms or 2.83Vpeak - that's 1W at 8 Ohms, 2W at 4 Ohm

2.83V RMS is 1watt @ 8 ohms. (2W @ 4ohms) The peak voltage will be 4V, or 8V peak to peak.

2V RMS is 1 watt @ 4ohms. (0.5W @ 8ohms) The peak voltage will be 2.83V, or 5.65V peak to peak)

An AC voltmeter/DMM will read either True RMS or Average, which on a 60HZ sinewave will be the same (or close enough) :)
 

RayDunzl

Grand Contributor
Central Scrutinizer
Joined
Mar 9, 2016
Messages
13,198
Likes
16,981
Location
Riverview FL
Oooh...

My bad... Should have compared my volatile memory to the calculator...
 
OP
F

FrantzM

Major Contributor
Forum Donor
Joined
Mar 12, 2016
Messages
4,337
Likes
7,730
Hi

I was trying to measure the sensitivity of my subwoofers. Lowish perhaps 83 dB but they were rattling like crazy. I decided to ditch the Leaktite buckets and went for 5-gallons paint buckets ... The Quikrete is setting now in these new enclosures and I will get back to the subs later and tell you all about them :)
 

bigx5murf

Addicted to Fun and Learning
Joined
Nov 6, 2018
Messages
522
Likes
343
Did you ever end up measuring just the subs? The plans say this thing should be flat down to 25Hz. But plugging the specs into BassBox6 is showing F3 of 50Hz and F6 of 43Hz. While 25Hz is at -16db. There also seems to be a slight peak from 85Hz to 105Hz.
 
Top Bottom