DIY Sub project

[SLAYER]

Hi folks,
this will be my first diy home sub project
i have not decided on driver yet
was considering dayton 12" or above
also the sub will be an imitation to sonotube but square
im considering going with dayton plate amp.
how much power do i need?
will 500 watt be enough?
the box outside dimensions im thinking is about(could be taller) 24"x24"x48"
have not thought about weather im going sealed or ported or maybe passive radiator as port

any input/help will be apreciated thanks guys

[SLAYER]

I seem to be alone in this .
oh well.
anywho im starting to settle on dayton 15" titanic 295-420
http://www.partsexpress.com/pe/pshow...0&ctab=10#Tabs

[Mike P.]

Hi Slayer,
The Dayton is a good sub. As for how much power, you'll need to narrow things down a bit whether you want sealed or ported. Is this strictly for HT ?

[SLAYER]

hi,thanks for replying mike.
yes i want to concentrate on ht.
is ported better suited for that purpose?
as for music my preference is BASS (DJ MAGIC MIKE "FEEL THE BASS")but thats another sub
for this project i want to concentrate on ht i have full range speakers at 40 hz which sound great
paired with onkyo 504
but im missing the feel of things.
i want to build something that will throw me of my chair "if such thing is possible"

[Mike P.]

How big is yout HT room?

[SLAYER]

my temp "ht" room is 12'x12'x8'(high)

[SLAYER]

thanks for taking time out to help.
i know its a small room but thats what i have now.
i have a cheap $100 sub and actually considered getting another, beacause of the room.
but thats not what i want.
i want to make something that will rival any retail sub outthere including svs.

[SLAYER]

i considered using a sonotube but the pictures ive seen of finished LLT so far are rather ugly
(no pun intended or disrespect to anyone) so i decided to go with a big and tall box with a rosenut finish.
from all the info i have read a down firing sub/port on top is the best combination to achieve my purpose? if thats true then considering the driver i chose all i need is to know how much power i need and how low should it be tuned .
i dont worry about room size since i use to have my own house with a living room space twice that.
if when i finish this project i feel i need more power i could always build another sub
as for the plate amp i want to go with dayton .

[Mike P.]

Your box design will be 12.5 cu. ft. net. Tuning should be 15 Hz with one 6 inch port 23 inches long. Cone excursion is reached at 21 Hz and 13.5 Hz with 360 watts. SPL in the low end should be around the 110 Db mark plus room gain. This is all according to WinISD. For this setup 500 watts would be enough.

[SLAYER]

thank you very much mike
now to ask a stupid question
is that considered a monster sub for ht use?
and what sub model/make would it rival?

[Mike P.]

No such thing as a stupid question when you're learning things. If you mean "monster" size, then the definition of a monster sub would be a Steve Callas sonotube. Yours will be big, but not that big. If you mean "monster" output, yours will do well. There's always bigger and better, especially when you get into the 18 inch subs. I can't say which make and model yours will compare to as I'm not to familiar with "commercial" subs. Maybe someone else can chime in here and give you an idea.

[SLAYER]

you're right, i am learning a lot

[SLAYER]

so i settled on dayton 500 watt plate amp , wish i could afford the bigger one oh well
http://www.partsexpress.com/pe/showd...816216#reviews

and heres the driver again
http://www.partsexpress.com/pe/showd...474156#reviews
also these seem like a good idea
http://www.partsexpress.com/pe/showd...857907#reviews

i wonder whats the best thing to use for a port

[SLAYER]

question is this recomended ?
and if so whats the thickness recomended?
http://www.partsexpress.com/webpage....ctGroup_ID=137

[Mike P.]

If you want to keep the cost down, then use a 6 inch diameter piece of sonotube for the port. Use a router and a round over bit to "flare" the end. A cheap way to line the sub is to use egg crate foam from WalMart. They sell it as mattress pads for about 15 dollars. There should be enough in a "twin size" to line the walls. The Acousta-Stuf you linked to is for stuffing a sealed sub or for adding to a ported sub to make the box seem bigger to the woofer, which you don't need to do.

[Geoff St. Germain]

I'm going to move this thread to the DIY Subwoofer section.

[SLAYER]

hi mike, i think i know what you mean, but is that a necesity? will it help with the sound?

well i started looking for mdf and other resources its a good thing i deciced on this particular box for the ease of use .

even i cant screw this up

http://www.homedepot.com/webapp/wcs/...ctId=100012018

[SLAYER]

are these the clamps to use for the cabinet?
i remember they being $20 , is there anything cheaper?

http://www.homedepot.com/webapp/wcs/...ctId=100154253

[hddummy]

If you want more power, you could always get the buttkicker amp for that same price.

http://www.thebuttkicker.com/home_th...bka1000-4a.htm

twice the juice, less bell-and-whistles.

[Geoff St. Germain]

hddummy wrote:

If you want more power, you could always get the buttkicker amp for that same price.

http://www.thebuttkicker.com/home_th...bka1000-4a.htm

twice the juice, less bell-and-whistles.

Depending on how the PE amp actually measures, the buttkicker may not offer much more power. The buttkicker was measured by a guy on the AVS forum and it managed 720 W @ 1 kHz @ 4 ohms with 6% THD and 550 W @ 1 kHz @ 4 ohms with 1 % THD. To be "fair" the specs on the Buttkicker site don't list the THD or frequency for the specs. I still find them to be misleading, though it is designed to power shakers, so perhaps for that application the distortion isn't much of an issue. I can't guarantee that the PE amp performs any better, especially since the specs on the site don't list either the frequency or distortion level for it's rated output, but I would be wary of using the Buttkicker.

[SLAYER]

500 Watt Class G Subwoofer Amplifier
#300-806
Specifications
Rated Power Output: 273 Watts MAX. into 8 ohms @ .06 % THD
540 Watts MAX. into 4 ohms @ .15 % THD
Operation of the amplifier at nominal
impedances below 4 ohms is not
recommended and may void the warranty.
Signal to Noise Ratio: 98 dB A-weighted
Efficiency: 75%
Input Impedance: 12K ohms
Dimensions: 11-15/16” W x 11-15/16” H x 5-¼” D
Enclosure Cutout: 10” x 10”
Power Requirements: 110-120 VAC, 60 Hz (8A GMA fuse)
Weight: 15.2 lbs.
PARTS EXPRESS
725 Pleasant Valley Dr., Springboro, OH 45066-1158
PHONE: 937-743-3000 FAX: 937-743-1677

Thank you for purchasing the #300-806 subwoofer amplifier. This amplifier offers a new level of
high fidelity performance when combined with the modern generation of high power/high
Xmax subwoofers. Key features of this sub amp include patented Class G circuitry used
exclusively in premium amp designs, a hefty toroidal power supply transformer, an ultra
efficient design that eliminates the need for bulky heat sinks, and a sophisticated fully
parametric equalizer that permits the user to achieve optimum performance in almost any
room environment. The amp is fully protected against thermal overload and excessive line
draw, and also contains advanced “soft clip” circuitry to eliminate the harsh sound and
potential speaker overload that can result from occasional input peaks.
Class G designs employ the proven high fidelity circuit characteristics of Class AB without
compromising audio quality and reliability the way some Class D or Class H designs can. A
Class G circuit makes both a low level supply and a high level supply available to the output
devices, instead of the single supply in less advanced designs. The voltage is delivered by
whichever supply “rail” matches the actual demand, so the output stage only draws the exact
amount of power that is required at any given time. This results in an operating efficiency of
up to 86%, and a corresponding reduction in heat.
Input Connections
Left/Right Inputs: RCA style jacks that will accept standard line level inputs from a preamp level source. They will
accept a stereo signal and internally combine it into mono. Both left and right input jacks must
be connected to the source in order to drive the amplifier to full output. The use of a “Y” cord is
suggested if a mono source is all that is available.
LFE Direct Input: RCA jack that will accept a signal from the mono LFE (Low Frequency Effects) output on a preamp
or receiver that is equipped with a dedicated sub bass output. This input bypasses the
amplifier’s own internal low pass filter circuitry, relying instead on the processed output
provided by the source equipment. This would be the recommended connection for most home
theatre surround sound receivers and pre-amps. We would also suggest the use of the LFE
input when an external line level electronic crossover or frequency dividing network is used.
Power Input: This unit features an IEC grounding type power input connector. The IEC connector allows the
user to quickly exchange the power cord if it is damaged, or if a longer cord is desired. The IEC
inlet connector also features an integrated fuse holder that contains the AC line fuse.
Controls/Indicators
Low Pass, Gain: Will match the amplifier’s input sensitivity to the output of the pre-amp source. If the source
output has a variable control, we recommend that the user spend a moment or two determining
the best balance between the two controls. When a balance is found between low noise, linear
level control, and sufficient level to drive the amp to the required output, the gain knob can be
considered to be the “volume control” for the subwoofer system.
Low Pass, Frequency: This control is used to establish the highest frequency that the subwoofer will reproduce and
has a range between 30 and 200 Hz. If your main speakers have good bass capability, you
could set the control to a fairly low value at 40, 60, or even 100 Hz. If the main speakers are
smaller or do not have much bass output, set the control higher. Experiment with the amount of
“overlap” that you will experience when all speakers are playing in the same range. This can be
helpful when integrating the subwoofer with the rest of the system and with the room.
Power LED: When the power switch is moved to the “on” position, the LED will illuminate in green, and the
amp will be in “stand by” mode. If a low level signal of about 3 millivolts or greater is applied to
the input, the light will change color to yellow to indicate that the amplifier is fully operational
and receiving typical music program. As input signal increases to the onset of clipping the LED
will turn red, which indicates that the clip limiting circuitry is activated. If an input signal is not
detected for 10 to 15 minutes, the amp will go back to “stand by” mode and the LED will change
back to green.
Phase: This two-position (NOR = 0° phase and REV = 180° phase) switch helps to compensate for
differences in the acoustical and electrical characteristics between the subwoofer and the main
system speakers. The relative locations of speakers in the system can cause significant
disturbances in speaker interaction due to time delay issues, or the destructive phase
interferences that can occur at certain frequencies. The use of this switch in conjunction with
altering the location of the subwoofer can have a dramatic effect on system integration. The
“NOR” setting would be considered the normal or default setting, but be sure to experiment
during system set-up.
Parametric Equalizer
The #300-806 Amplifier features a fully parametric equalizer to help you to achieve the best possible subwoofer
performance. Professional sound engineers have for many years considered the parametric EQ to be one of the most
accurate, versatile, and high fidelity tools for audio enhancement. A greater degree of control can be achieved when using
the EQ’s unique ability to vary the frequency to be affected, the amount of boost or cut, and the width or narrowness at
the selected frequency.
EQ-Frequency: Establishes the specific frequency at which EQ boost or cut may be applied between
18 Hz and 80 Hz.
EQ-Bandwidth: Determines how narrow or wide the EQ curve will be within a range of 0.1 to 1.0. If for example
a frequency of 60 Hz were selected along with a Q of 0.1, the frequencies to either side of 60
Hz would be less affected. This is a narrow bandwidth that could be useful for “surgically”
removing an offending peak without disturbing adjacent frequencies. At the other extreme, a Q
of 1 would result in a much broader effect which could be used for smooth overall bass boost or
cut, to balance the overall tone character of the sub.
EQ-Level: Permits the application of up to 6dB of boost or 14.5dB of cut at the selected frequency and
bandwidth. Setting the control at the 0 position effectively removes the EQ from the circuit path.
It is good to remember that high levels of boost reduce amplifier headroom; it is the same as
turning up the low pass gain control but only at the selected EQ frequencies. It would be helpful
to reduce or increase the low pass gain control to balance the amount of cut or boost applied
by the EQ.
Notes About Hum
The addition of a new component to an existing system can sometimes result in an audible hum. While it would be easy to
assume that the new product is at fault or even defective, it is usually just an indicator that it is time to take a closer look at
the overall grounding of the audio system. To start with, verify that all audio equipment is on the same AC power circuit.
The outlets in an area may or may not all be on the same breaker, some could even be on a completely different breaker
panel. Always make sure that all equipment grounds are in good condition, and NEVER remove the ground pin from a
power plug. There are some cases where the actual power line has some form of interference but the most common
cause of noise is a ground loop, meaning that the system’s different ground points lack a common potential. The cable TV
line can be the cause of hum in multi-source home audio/video systems. Just temporarily disconnect the cable line, and if
the hum stops then the use of an inline isolation transformer (part #180-075) is suggested. Other situations may require
the installation of an improved earth ground (connection to a metal water pipe or grounding rod) in the vicinity of the
audio/video system. The key is to proceed slowly and step by step, taking care to identify which cables or combinations of
cables cause noise when connected.
PARTS EXPRESS
725 Pleasant Valley Dr., Springboro, OH 45066-1158
PHONE: 937-743-3000 FAX: 937-743-1677

[SLAYER]

what i find misleading about buttkicker amp is the fact that it states .

1100 watts at 4 ohms and 2100 watts at 2 ohms1050 watts per Buttkicker when 2 units are wired in parallelRCA and inputs with 160V and 1.25 Volt sensitivities eliminates the need for a separate pre-amplifier Variable high cutoff 40-160 Hz low cutoff 25 Hz switchable Class D switching technology and 120-240v switchable worldwide usage 12W x 4 3/8H x 11D1 year manufacturers warranty

and only costs $274.96