Best Subwoofer Design

[Haggar]

Hi,
Taken the plunge and I am making a subwoofer. Considering 2 designs 1)
Bandpass Parallel Double Tuned with the low F3 point at 27.56 Hz and
the high F3 point at 62.54 Hz. This design really suites the driver (a
Response 10" Jaycar PN CS-2274) and 2) standard bass reflex with the F3
point at 28.93 Hz. Not being a really experienced subwoofer user, will
the bandpass design have enough usable frequency(for movies and music)
considering that most subwoofer amplifiers have adjustable frequency
cutoff to around 150 Hz ? Interested to know what frequency most people
set the frequency cutoff to. If you need to know, the front/main
speakers that I will be using will have the F3 point at around 30 Hz,

cheers,
Glenn


--
Haggar

[Philip Vafiadis]

Haggar wrote:
> Hi,
> Taken the plunge and I am making a subwoofer. Considering 2 designs 1)
> Bandpass Parallel Double Tuned with the low F3 point at 27.56 Hz and
> the high F3 point at 62.54 Hz. This design really suites the driver (a
> Response 10" Jaycar PN CS-2274) and 2) standard bass reflex with the F3
> point at 28.93 Hz. Not being a really experienced subwoofer user, will
> the bandpass design have enough usable frequency(for movies and music)
> considering that most subwoofer amplifiers have adjustable frequency
> cutoff to around 150 Hz ? Interested to know what frequency most people
> set the frequency cutoff to. If you need to know, the front/main
> speakers that I will be using will have the F3 point at around 30 Hz,
> cheers, Glenn

Glen, if you intend using the subwoofer in a surround sound system for
the 'point 1' channel and/or with bass management, then extended high
end response is beneficial. Try to get at least one full octave of flat
response above any electical filtering (roll-off) points.

As a general comment, the low frequency -3dB point is just one thing to
consider in your subwoofer design. A sub also needs to be able to play
at a usefull SPL (volume) with low enough distortion to realisticaly
reproduce sound without making other obvious sounds (puffing, blapping,
rattling, buzzing etc). When designing your subwoofer, it is a mistake
to aim for the lowest -3dB point without consideration for the other
two factors. The majority of bass (and the loudest) in movies is
between 30Hz and 35Hz, you will need high output capability and low
distortion in this range.

There are many computer modeling software programs available now (and
low cost to download) but use them as a guide only. Achieving accurate
theoretical modeling results requires many driver and cabinet variables
to be measured and calculated. This is unlikely to be possible for the
casual constructor. Using this type of software is a good place to
start though, as they may help you to understand how all the various
parameters interact.

Kind regards
Philip Vafiadis
Founder, VAF Research Pty Ltd.

[Jocelyn Major]

Hello,
I check with WinISD and a bandpass does'nt look to be the best design
for the speaker you are using (Car Subwoofer). 1st the F3 point is very
close to your main speaker (F3 30Hz). The best design IMHO will be a
bass reflex base on a Isobaric Configuration. In that Configuration your
F3 will be 23Hz @-3dB, But you will need a second driver.

I Have a little question... Why did you choose a Car Subwoofer for a
home use?. Car Subwoofer are design to give lot of Bass in a very
confined environment. They are not design to give lot of "Clean" Bass in
a home environment. Most use of car Subwoofer in a home environment is
always far from HI-FI (Mainly very boomy, 1 note sub).

Always try to design a subwoofer that will play 1 octave lower that you
main loudspeaker. Since you main bottom out at 30Hz @ -3dB so you should
build a sub that "Idealy will go from 15 to 30Hz. But since not much is
being played below 20 you could design a great sub with a driver build
for Home use like the Perless 269SWR51XXLSS its -3dB is 19hz and you can
shoose a cutoff of 40 Hz.

My sub is an Isobaric consisting of a pair of 15in Speakerlab. Its spec
are as follows : F3 16Hz @-3dB, Upper cutouf is 40hz @ -3dB. Most of the
time it make no sound at all, but when needed it shows. The experience
is viceral.

Good Luck with your Project

Jocelyn

Haggar a écrit :
> Hi,
> Taken the plunge and I am making a subwoofer. Considering 2 designs 1)
> Bandpass Parallel Double Tuned with the low F3 point at 27.56 Hz and
> the high F3 point at 62.54 Hz. This design really suites the driver (a
> Response 10" Jaycar PN CS-2274) and 2) standard bass reflex with the F3
> point at 28.93 Hz. Not being a really experienced subwoofer user, will
> the bandpass design have enough usable frequency(for movies and music)
> considering that most subwoofer amplifiers have adjustable frequency
> cutoff to around 150 Hz ? Interested to know what frequency most people
> set the frequency cutoff to. If you need to know, the front/main
> speakers that I will be using will have the F3 point at around 30 Hz,
>
> cheers,
> Glenn
>
>

[Mark Hathaway]

Hello Haggar and Jocelyn

Its been a long time since I ran the numbers on the xls' I've used, with 2
passive radiators loaded up to IIRC 600grams, in an extended bass shelf
alignment, which yeilds great in room response, my measured f3 was below
10hz uncorrected. (i'm running a tact rcs on it too) The peerless XLS
drivers, not sure on the XXLSS, can be obtained form wes components, leagues
in front of the jaycar drivers.

BUT impedance is rather low for the xls, drops below 3 ohms in certain
alignments.

unibox, http://www.pvconsultants.com/audio/boxmodel/unibox.htm is free and a
lot better then winisd, etc, for modelling your drivers intended alignment.
Vance Dickasons book, "loudspeaker design cookbook" is well worth
purchasing.

www.madisound.com who are an online retailer of drivers big and small, have
a great discussion board you should check out.

A BIG sub that measures flat anechoic can sound pretty bad inroom, flat to
20hz (or whatever) in an anechoic environment, when in a room with room gain
added on the top, can sound similar to one note car bass.

Enjoy the experience of building your own sub, just because you've built it
yourself doesn't mean the design will work for you in YOUR room as well as
expected first time round, it can take a few tries. It helps if you've had a
listen to a good variety of commercial offerings


Regards,
Mark Hathaway













"Jocelyn Major" <majorj@videotron.ca> wrote in message
news:xdyoe.1350$Ab4.898@weber.videotron.net...
> Hello,
> I check with WinISD and a bandpass does'nt look to be the best design for
> the speaker you are using (Car Subwoofer). 1st the F3 point is very close
> to your main speaker (F3 30Hz). The best design IMHO will be a bass reflex
> base on a Isobaric Configuration. In that Configuration your F3 will be
> 23Hz @-3dB, But you will need a second driver.
>
> I Have a little question... Why did you choose a Car Subwoofer for a home
> use?. Car Subwoofer are design to give lot of Bass in a very confined
> environment. They are not design to give lot of "Clean" Bass in a home
> environment. Most use of car Subwoofer in a home environment is always far
> from HI-FI (Mainly very boomy, 1 note sub).
>
> Always try to design a subwoofer that will play 1 octave lower that you
> main loudspeaker. Since you main bottom out at 30Hz @ -3dB so you should
> build a sub that "Idealy will go from 15 to 30Hz. But since not much is
> being played below 20 you could design a great sub with a driver build for
> Home use like the Perless 269SWR51XXLSS its -3dB is 19hz and you can
> shoose a cutoff of 40 Hz.
>
> My sub is an Isobaric consisting of a pair of 15in Speakerlab. Its spec
> are as follows : F3 16Hz @-3dB, Upper cutouf is 40hz @ -3dB. Most of the
> time it make no sound at all, but when needed it shows. The experience is
> viceral.
>
> Good Luck with your Project
>
> Jocelyn
>
> Haggar a écrit :
>> Hi,
>> Taken the plunge and I am making a subwoofer. Considering 2 designs 1)
>> Bandpass Parallel Double Tuned with the low F3 point at 27.56 Hz and
>> the high F3 point at 62.54 Hz. This design really suites the driver (a
>> Response 10" Jaycar PN CS-2274) and 2) standard bass reflex with the F3
>> point at 28.93 Hz. Not being a really experienced subwoofer user, will
>> the bandpass design have enough usable frequency(for movies and music)
>> considering that most subwoofer amplifiers have adjustable frequency
>> cutoff to around 150 Hz ? Interested to know what frequency most people
>> set the frequency cutoff to. If you need to know, the front/main
>> speakers that I will be using will have the F3 point at around 30 Hz,
>>
>> cheers,
>> Glenn
>>

[Haggar]

Mark Hathaway Wrote:
> Hello Haggar and Jocelyn
>
> Its been a long time since I ran the numbers on the xls' I've used,
> with 2
> passive radiators loaded up to IIRC 600grams, in an extended bass
> shelf
> alignment, which yeilds great in room response, my measured f3 was
> below
> 10hz uncorrected. (i'm running a tact rcs on it too) The peerless XLS
> drivers, not sure on the XXLSS, can be obtained form wes components,
> leagues
> in front of the jaycar drivers.
>
> BUT impedance is rather low for the xls, drops below 3 ohms in certain
> alignments.
>
> unibox, http://www.pvconsultants.com/audio/boxmodel/unibox.htm is free
> and a
> lot better then winisd, etc, for modelling your drivers intended
> alignment.
> Vance Dickasons book, "loudspeaker design cookbook" is well worth
> purchasing.
>
> www.madisound.com who are an online retailer of drivers big and small,
> have
> a great discussion board you should check out.
>
> A BIG sub that measures flat anechoic can sound pretty bad inroom, flat
> to
> 20hz (or whatever) in an anechoic environment, when in a room with room
> gain
> added on the top, can sound similar to one note car bass.
>
> Enjoy the experience of building your own sub, just because you've
> built it
> yourself doesn't mean the design will work for you in YOUR room as well
> as
> expected first time round, it can take a few tries. It helps if you've
> had a
> listen to a good variety of commercial offerings
>
>
> Regards,
> Mark Hathaway
>
>
>
>
>
>
>
>
>
>
>
>
>
> "Jocelyn Major" <majorj@videotron.ca> wrote in message
> news:xdyoe.1350$Ab4.898@weber.videotron.net...
> > Hello,
> > I check with WinISD and a bandpass does'nt look to be the best design
> for
> > the speaker you are using (Car Subwoofer). 1st the F3 point is very
> close
> > to your main speaker (F3 30Hz). The best design IMHO will be a bass
> reflex
> > base on a Isobaric Configuration. In that Configuration your F3 will
> be
> > 23Hz @-3dB, But you will need a second driver.
> >
> > I Have a little question... Why did you choose a Car Subwoofer for a
> home
> > use?. Car Subwoofer are design to give lot of Bass in a very
> confined
> > environment. They are not design to give lot of "Clean" Bass in a
> home
> > environment. Most use of car Subwoofer in a home environment is
> always far
> > from HI-FI (Mainly very boomy, 1 note sub).
> >
> > Always try to design a subwoofer that will play 1 octave lower that
> you
> > main loudspeaker. Since you main bottom out at 30Hz @ -3dB so you
> should
> > build a sub that "Idealy will go from 15 to 30Hz. But since not much
> is
> > being played below 20 you could design a great sub with a driver
> build for
> > Home use like the Perless 269SWR51XXLSS its -3dB is 19hz and you can
> > shoose a cutoff of 40 Hz.
> >
> > My sub is an Isobaric consisting of a pair of 15in Speakerlab. Its
> spec
> > are as follows : F3 16Hz @-3dB, Upper cutouf is 40hz @ -3dB. Most of
> the
> > time it make no sound at all, but when needed it shows. The
> experience is
> > viceral.
> >
> > Good Luck with your Project
> >
> > Jocelyn
> >
> > Haggar a écrit :
> >> Hi,
> >> Taken the plunge and I am making a subwoofer. Considering 2 designs
> 1)
> >> Bandpass Parallel Double Tuned with the low F3 point at 27.56 Hz
> and
> >> the high F3 point at 62.54 Hz. This design really suites the driver
> (a
> >> Response 10" Jaycar PN CS-2274) and 2) standard bass reflex with the
> F3
> >> point at 28.93 Hz. Not being a really experienced subwoofer user,
> will
> >> the bandpass design have enough usable frequency(for movies and
> music)
> >> considering that most subwoofer amplifiers have adjustable
> frequency
> >> cutoff to around 150 Hz ? Interested to know what frequency most
> people
> >> set the frequency cutoff to. If you need to know, the front/main
> >> speakers that I will be using will have the F3 point at around 30
> Hz,
> >>
> >> cheers,
> >> Glenn
> >>

Thanks guys for your feedback. I am no expert on speaker design and I
did not actually realise that the Jaycar sub I bought was designed for
a car, I grabbed it as it was a discontinued model and going cheap $50,
and when I checked it with some speaker calculators, it looked to have
good low end responses compared to some other ones for sale. How can
you tell which subs are designed for cars or Home theatre ? (if the
supplier does not state)

Mark,
Just so I can do a comparison, can you give me a link(or a current part
number) to a suitable sub speaker(peerless OK, could not seem to find a
suitable one on the link that you gave me) for the home and I'll run
some more calculations, including the one that you recommended.

I am making a sub really just for fun, I don't expect that it will be
an award winner, but I do like good quality base, mainly for HT and
general music, does not need to be loud, I'm past that stage. My budget
is small, not really in a hurry, and have not sorted amplication yet,

cheers, Glenn


--
Haggar

[Jocelyn Major]

Hello Glenn,

You can check at www.solen.ca they have several subwoofer. About how to
know is a sub is designed for a car or home look at the impedance. Most
4 ohms sub are design for Car but some 4 ohms are also designed for home
except they are design to be used as a pair connected in series in an
isobaric configuration. The sub I design personnally are build around a
pair of Speakerlab W1504s. Those are a pair of 15inch 4 ohms with a fs
of 18hz the f3 of my Sub is 18Hz @ -3db and they still give enough
power at 16Hz. They are flat from 18 to 100hz, the upper crossover
cutoff is 40Hz. It took me 3 days to build it but 2 weeks of tuning
until it was perfect. I am lucky enough to have a room where the longest
wall is exactly 32 feet so yes the sub-bass is tremendous. When you
design a sub take the longuest wall length in consideration because that
will be the longuest wave length you will get. I listen a lot to organ
music an I am lucky to have a room big enough to allow me to feel the 32
feet pedal organ (16HZ) since those 15 inch with the 512 Watts subwoofer
amps I get at Solen can really move a lot a air That is a problem with a
lot of sub with below 10 inch driver: 1st: a 8 inch cannot move lot of
air. 2nd: Most of the time they are powered with a 50-100 watts sub amps
so they rarely give a 30Hz @ 110dB and if they do it is with so much
distortion that they are not listenable. The Jaycar can go to 110dB but
at this level can it go at 30Hz without cone breakout?

Here is a link to Speakerbuilding web site where you can find info on
building speakers including several sub.
http://www.speakerbuilding.com/diy/

A link on various DIY audio project
http://web.telia.com/~u87124019/diy.html

Also here is a link showing a picture of my sub with some pictures of my
latest tower speakers
http://groups.msn.com/u6f19vq00q2r6ibekubq2bsbh1/enceintes.msnw?Page=1

Haggar a écrit :
> Mark Hathaway Wrote:
>
>>Hello Haggar and Jocelyn
>>
>>Its been a long time since I ran the numbers on the xls' I've used,
>>with 2
>>passive radiators loaded up to IIRC 600grams, in an extended bass
>>shelf
>>alignment, which yeilds great in room response, my measured f3 was
>>below
>>10hz uncorrected. (i'm running a tact rcs on it too) The peerless XLS
>>drivers, not sure on the XXLSS, can be obtained form wes components,
>>leagues
>>in front of the jaycar drivers.
>>
>>BUT impedance is rather low for the xls, drops below 3 ohms in certain
>>alignments.
>>
>>unibox, http://www.pvconsultants.com/audio/boxmodel/unibox.htm is free
>>and a
>>lot better then winisd, etc, for modelling your drivers intended
>>alignment.
>>
Yes it is better than WinIsd except that it was not stable enough on my
older computer.
Vance Dickasons book, "loudspeaker design cookbook" is well worth
>>purchasing.
A very good books likeDavid B. Webbs book, "How to design, build & test
complete speaker systems"

>>www.madisound.com who are an online retailer of drivers big and small,
>>have great discussion board you should check out.
>>
>>A BIG sub that measures flat anechoic can sound pretty bad inroom, flat
>>to 20hz (or whatever) in an anechoic environment, when in a room with room
>>gain dded on the top, can sound similar to one note car bass.
Like several cheap subs.
>>Enjoy the experience of building your own sub, just because you've
>>built it yourself doesn't mean the design will work for you in YOUR room as well
>>as expected first time round, it can take a few tries. It helps if you've
>>had a listen to a good variety of commercial offerings
May I had a variety of *good* commercial offerings. There is a big
quantity of sub on the market.
Some very good and several really not so good. I have listened to
several sub (commercial and diy) and I have see some diy that where
simple incredible and I have see several sub (several of them come with
all in a box Home Theatre) that where incredibly bad (mostly one note
bass).


>>
>>Regards,
>>Mark Hathaway
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>"Jocelyn Major" <majorj@videotron.ca> wrote in message
>>news:xdyoe.1350$Ab4.898@weber.videotron.net...
>>
>>>Hello,
>>>I check with WinISD and a bandpass does'nt look to be the best design
>>
>>for
>>
>>>the speaker you are using (Car Subwoofer). 1st the F3 point is very
>>
>>close
>>
>>>to your main speaker (F3 30Hz). The best design IMHO will be a bass
>>
>>reflex
>>
>>>base on a Isobaric Configuration. In that Configuration your F3 will
>>
>>be
>>
>>>23Hz @-3dB, But you will need a second driver.
>>>
>>>I Have a little question... Why did you choose a Car Subwoofer for a
>>
>>home
>>
>>>use?. Car Subwoofer are design to give lot of Bass in a very
>>
>>confined
>>
>>>environment. They are not design to give lot of "Clean" Bass in a
>>
>>home
>>
>>>environment. Most use of car Subwoofer in a home environment is
>>
>>always far
>>
>>>from HI-FI (Mainly very boomy, 1 note sub).
>>>
>>>Always try to design a subwoofer that will play 1 octave lower that
>>
>>you
>>
>>>main loudspeaker. Since you main bottom out at 30Hz @ -3dB so you
>>
>>should
>>
>>>build a sub that "Idealy will go from 15 to 30Hz. But since not much
>>
>>is
>>
>>>being played below 20 you could design a great sub with a driver
>>
>>build for
>>
>>>Home use like the Perless 269SWR51XXLSS its -3dB is 19hz and you can
>>>shoose a cutoff of 40 Hz.
>>>
>>>My sub is an Isobaric consisting of a pair of 15in Speakerlab. Its
>>
>>spec
>>
>>>are as follows : F3 16Hz @-3dB, Upper cutouf is 40hz @ -3dB. Most of
>>
>>the
>>
>>>time it make no sound at all, but when needed it shows. The
>>
>>experience is
>>
>>>viceral.
>>>
>>>Good Luck with your Project
>>>
>>>Jocelyn
>>>
>>>Haggar a écrit :
>>>
>>>>Hi,
>>>>Taken the plunge and I am making a subwoofer. Considering 2 designs
>>
>>1)
>>
>>>>Bandpass Parallel Double Tuned with the low F3 point at 27.56 Hz
>>
>>and
>>
>>>>the high F3 point at 62.54 Hz. This design really suites the driver
>>
>>(a
>>
>>>>Response 10" Jaycar PN CS-2274) and 2) standard bass reflex with the
>>
>>F3
>>
>>>>point at 28.93 Hz. Not being a really experienced subwoofer user,
>>
>>will
>>
>>>>the bandpass design have enough usable frequency(for movies and
>>
>>music)
>>
>>>>considering that most subwoofer amplifiers have adjustable
>>
>>frequency
>>
>>>>cutoff to around 150 Hz ? Interested to know what frequency most
>>
>>people
>>
>>>>set the frequency cutoff to. If you need to know, the front/main
>>>>speakers that I will be using will have the F3 point at around 30
>>
>>Hz,
>>
>>>>cheers,
>>>>Glenn
>>>>
>
>
> Thanks guys for your feedback. I am no expert on speaker design and I
> did not actually realise that the Jaycar sub I bought was designed for
> a car, I grabbed it as it was a discontinued model and going cheap $50,
> and when I checked it with some speaker calculators, it looked to have
> good low end responses compared to some other ones for sale. How can
> you tell which subs are designed for cars or Home theatre ? (if the
> supplier does not state)
>
> Mark,
> Just so I can do a comparison, can you give me a link(or a current part
> number) to a suitable sub speaker(peerless OK, could not seem to find a
> suitable one on the link that you gave me) for the home and I'll run
> some more calculations, including the one that you recommended.
>
> I am making a sub really just for fun, I don't expect that it will be
> an award winner, but I do like good quality base, mainly for HT and
> general music, does not need to be loud, I'm past that stage. My budget
> is small, not really in a hurry, and have not sorted amplication yet,
>
> cheers, Glenn
>
>

[Mark Hathaway]

Hello Haggar,


the peerless range can be seen here at the manufactures website:
http://www.tymphany.com/prodpeerless.php


a 830847 or a 830846 would be a good driver to use, worth saving up your
pennies for.


Regards,
Mark



"Haggar" <Haggar.1q5n3p@no-mx.forums.eyo.com.au> wrote in message
news:Haggar.1q5n3p@no-mx.forums.eyo.com.au...
>
> Mark Hathaway Wrote:
>> Hello Haggar and Jocelyn
>>
>> Its been a long time since I ran the numbers on the xls' I've used,
>> with 2
>> passive radiators loaded up to IIRC 600grams, in an extended bass
>> shelf
>> alignment, which yeilds great in room response, my measured f3 was
>> below
>> 10hz uncorrected. (i'm running a tact rcs on it too) The peerless XLS
>> drivers, not sure on the XXLSS, can be obtained form wes components,
>> leagues
>> in front of the jaycar drivers.
>>
>> BUT impedance is rather low for the xls, drops below 3 ohms in certain
>> alignments.
>>
>> unibox, http://www.pvconsultants.com/audio/boxmodel/unibox.htm is free
>> and a
>> lot better then winisd, etc, for modelling your drivers intended
>> alignment.
>> Vance Dickasons book, "loudspeaker design cookbook" is well worth
>> purchasing.
>>
>> www.madisound.com who are an online retailer of drivers big and small,
>> have
>> a great discussion board you should check out.
>>
>> A BIG sub that measures flat anechoic can sound pretty bad inroom, flat
>> to
>> 20hz (or whatever) in an anechoic environment, when in a room with room
>> gain
>> added on the top, can sound similar to one note car bass.
>>
>> Enjoy the experience of building your own sub, just because you've
>> built it
>> yourself doesn't mean the design will work for you in YOUR room as well
>> as
>> expected first time round, it can take a few tries. It helps if you've
>> had a
>> listen to a good variety of commercial offerings
>>
>>
>> Regards,
>> Mark Hathaway
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> "Jocelyn Major" <majorj@videotron.ca> wrote in message
>> news:xdyoe.1350$Ab4.898@weber.videotron.net...
>> > Hello,
>> > I check with WinISD and a bandpass does'nt look to be the best design
>> for
>> > the speaker you are using (Car Subwoofer). 1st the F3 point is very
>> close
>> > to your main speaker (F3 30Hz). The best design IMHO will be a bass
>> reflex
>> > base on a Isobaric Configuration. In that Configuration your F3 will
>> be
>> > 23Hz @-3dB, But you will need a second driver.
>> >
>> > I Have a little question... Why did you choose a Car Subwoofer for a
>> home
>> > use?. Car Subwoofer are design to give lot of Bass in a very
>> confined
>> > environment. They are not design to give lot of "Clean" Bass in a
>> home
>> > environment. Most use of car Subwoofer in a home environment is
>> always far
>> > from HI-FI (Mainly very boomy, 1 note sub).
>> >
>> > Always try to design a subwoofer that will play 1 octave lower that
>> you
>> > main loudspeaker. Since you main bottom out at 30Hz @ -3dB so you
>> should
>> > build a sub that "Idealy will go from 15 to 30Hz. But since not much
>> is
>> > being played below 20 you could design a great sub with a driver
>> build for
>> > Home use like the Perless 269SWR51XXLSS its -3dB is 19hz and you can
>> > shoose a cutoff of 40 Hz.
>> >
>> > My sub is an Isobaric consisting of a pair of 15in Speakerlab. Its
>> spec
>> > are as follows : F3 16Hz @-3dB, Upper cutouf is 40hz @ -3dB. Most of
>> the
>> > time it make no sound at all, but when needed it shows. The
>> experience is
>> > viceral.
>> >
>> > Good Luck with your Project
>> >
>> > Jocelyn
>> >
>> > Haggar a écrit :
>> >> Hi,
>> >> Taken the plunge and I am making a subwoofer. Considering 2 designs
>> 1)
>> >> Bandpass Parallel Double Tuned with the low F3 point at 27.56 Hz
>> and
>> >> the high F3 point at 62.54 Hz. This design really suites the driver
>> (a
>> >> Response 10" Jaycar PN CS-2274) and 2) standard bass reflex with the
>> F3
>> >> point at 28.93 Hz. Not being a really experienced subwoofer user,
>> will
>> >> the bandpass design have enough usable frequency(for movies and
>> music)
>> >> considering that most subwoofer amplifiers have adjustable
>> frequency
>> >> cutoff to around 150 Hz ? Interested to know what frequency most
>> people
>> >> set the frequency cutoff to. If you need to know, the front/main
>> >> speakers that I will be using will have the F3 point at around 30
>> Hz,
>> >>
>> >> cheers,
>> >> Glenn
>> >>
>
> Thanks guys for your feedback. I am no expert on speaker design and I
> did not actually realise that the Jaycar sub I bought was designed for
> a car, I grabbed it as it was a discontinued model and going cheap $50,
> and when I checked it with some speaker calculators, it looked to have
> good low end responses compared to some other ones for sale. How can
> you tell which subs are designed for cars or Home theatre ? (if the
> supplier does not state)
>
> Mark,
> Just so I can do a comparison, can you give me a link(or a current part
> number) to a suitable sub speaker(peerless OK, could not seem to find a
> suitable one on the link that you gave me) for the home and I'll run
> some more calculations, including the one that you recommended.
>
> I am making a sub really just for fun, I don't expect that it will be
> an award winner, but I do like good quality base, mainly for HT and
> general music, does not need to be loud, I'm past that stage. My budget
> is small, not really in a hurry, and have not sorted amplication yet,
>
> cheers, Glenn
>
>
> --
> Haggar

[conradvr@yahoo.com]

Hi Haggar,

You may be able to use your sub and get a 'good enough' result. I did
my own project about 2 years ago and found using the Speaker Workshop
project (www.speakerworkshop.com) a great tool as you can measure the
drivers parameters and then design the enclosure on these measurements
(most published data is inaccurate). My final design used the Peerless
XLS and passive radioators. A design is also given at
http://www.linkwitzlab.com/thor-intro.htm - has some interesting
comments by the designer on factors that are important to him.

Good luck and enjoy
Con