The Subwoofer DIY Page v1.1
[ The Subwoofer DIY Page - Discussion Forum ] [ FAQ ]

Choosing a system
Sealed Systems
Ported Systems
Passive Radiator Systems
4th Order Bandpass Systems
6th Order Bandpass Systems
Transmission Line Systems
Dipole Systems
Car Audio Subwoofers

[Previous Message] [Next Message]

Date: September 23, 2013 at 17:44:25
From: shawn, [174-21-54-34.tukw.qwest.net]
Subject: Looking for help with driver selection and frequency calculations


I am looking to build a subwoofer for ht. It will be
about 50/50 for music and movies, my emphasis is more
on the movie side though. I want to build a ported sub
for the lower range for movies.my understanding is i
want the qts to be in the 30's for this. my experience
is pretty limited and alot of these numbers dont make
since to me. right now i have a 5.0 set up sony
strdh720, two polk audio monitor 45b as rears, tritrix
center and two old klh full range floor speakers (plan
to build the tritrix TL after the sub). Hopefully i
will be moving within a couple of years so i dont want
to build around my current living room.

right now i have two drivers in mind
http://www.parts-express.com/pe/showdetl.cfm?
Partnumber=295-467

http://www.madisoundspeakerstore.com/approx-12-
subwoofers/scanspeak-discovery-30w/4558t-12-subwoofer/

For the scanspeak i came up with the following
fs 17hz
qts .32
qes .34
vas 197L
vb 91.7257244 L
FB 21.54572909 hz
F3 23.7967668
DBPeak .053650195
pe max 350w
dia 28cm
xmax 12.5mm
SPL 86.3841117
PAR .569934257
PER 207.689046
Peak SPL 11.8247921

For the dayton
FS 20.9hz
qts .38
qes .42
vas 60.031
vb 49.28235382
fb 22.21825455
f3 22.7955216
dbpeak .068576919
pemax 1400w
dia 30.48cm
xmax 14mm
spl 82.99647153
par .777985571
per 618.4781903
peak spl 114.4577519

It looks to me as though the ss would be the better
speaker. do i understand it correctly that it would
require a 200 watt amp? i dont mind the larger box i
plan on making this into a side table. I plan on making
a isosceles trapezoidal prism with a round table on
top. roughly a base of 24in a top of 12in and a height
of 26in with all four sides the same. I will adjust the
size as needed. The dayton sounds like it was made for
cars. I am open to suggestions of other drivers, i
would like to keep it under $400.

When i did the frequency responce calculations on
either of these the numbers always came out negative,
is this normal? just plug in any number for F right?
such as 20hz. Thanks for any help/advice.
Moderated By: brian@diysubwoofers.org


  • View entire thread
  • Posted with TalkShop version 2.77 BETA

    [Previous Message] [Next Message]




    Follow Ups:

    [ The Subwoofer DIY Page - Discussion Forum ] [ FAQ ]


    websmall.gif (584 bytes)