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(Complicated) Guitar Cab Tuning Question
(Complicated) Guitar Cab Tuning Question
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Old 5th November 2009, 06:40 AM   #31
andrewskaterrr is offline andrewskaterrr  United States
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Well how does a 4"Dia x 4 3/8"Len port on the back panel in the middle sound?
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Old 5th November 2009, 03:31 PM   #32
Peter M. is offline Peter M.  Norway
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Quote:
Originally Posted by andrewskaterrr View Post
from what I've read, that would give a funky load that the amp would see, you need to have the cap and induc as close to the same frequency as possible
Most speakers are a funky load anyway.
This same thing is often done in two and a half way hifi speakers to get more bass.
In your case removing the cap will even smooth out the resonance impedance peaks as seen by your amp.
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Old 5th November 2009, 04:05 PM   #33
MJL21193 is offline MJL21193  Canada
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Quote:
Originally Posted by andrewskaterrr View Post
The internal dimensions of the box are 13⅜"h x 28½"w x 11⅜" deep = a volume of 2.5 ft^3
The bracing is ¾" h x 1½" w and has a total length of 106" = a volume of .069 ft^3
So the volume of the box would be 2.431 ft^3

I need to know how I would calculate the volume of the 1½" foam, the inductor, and the front loaded drivers (baffle wood is ¾" thick)

Here are the specs of the drivers:
http://eminence.com/bassguitar_speak...2&SUB_CAT_ID=5

There are two drivers (obviously) so the port will have to be tuned for 300w.
That box is too small for 2 of those drivers (the basslite your link shows) in a vented system, it would need to be ~300 litres for optimal performance. Current box is ~60 litres.
Better to leave it sealed.
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Old 5th November 2009, 04:23 PM   #34
andrewskaterrr is offline andrewskaterrr  United States
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Quote:
Originally Posted by MJL21193 View Post
That box is too small for 2 of those drivers (the basslite your link shows) in a vented system, it would need to be ~300 litres for optimal performance. Current box is ~60 litres.
Better to leave it sealed.
I've calculated that my internal volume will be 2ft^3 of open space. i subtracted diver displacement, inductor volume, wire volume, and foam volume to get that 2ft^3

Are you sure it won't work??
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Old 5th November 2009, 04:37 PM   #35
MJL21193 is offline MJL21193  Canada
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Quote:
Originally Posted by andrewskaterrr View Post
I've calculated that my internal volume will be 2ft^3 of open space. i subtracted diver displacement, inductor volume, wire volume, and foam volume to get that 2ft^3

Are you sure it won't work??
How did you calculate?

I used Unibox, a simulator that I rely on 100% and it shows best performance for 2 of these drivers in a bigger box. A smaller box still "works" but the response will be peaking at ~110Hz:

117.PNG

2 Ports would be 10cm dia x 11cm long.
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Old 5th November 2009, 04:41 PM   #36
MJL21193 is offline MJL21193  Canada
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Compare that to a 250 litre box:

117.PNG

Much better low end response.
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Old 5th November 2009, 04:50 PM   #37
andrewskaterrr is offline andrewskaterrr  United States
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Quote:
Originally Posted by MJL21193 View Post
Compare that to a 250 litre box:

Attachment 145756

Much better low end response.
1. i noticed you're not using 300w as the power, each driver is 150w rms
2. what if i use 1 port 4"h 4 3/8"d
3. if you skim through my posts, I explain my specs and reasoning
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Old 5th November 2009, 04:58 PM   #38
MJL21193 is offline MJL21193  Canada
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The power of the drivers is inconsequential - how much power can your amp provide? At what power level does the driver run out of linear excursion? These are important factors.

You want to use the box you have, I don't blame you but to get the best sound from it, it should be sealed.
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Old 5th November 2009, 05:08 PM   #39
andrewskaterrr is offline andrewskaterrr  United States
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Quote:
Originally Posted by MJL21193 View Post
The power of the drivers is inconsequential - how much power can your amp provide? At what power level does the driver run out of linear excursion? These are important factors.

You want to use the box you have, I don't blame you but to get the best sound from it, it should be sealed.
it is already sealed. basically the cab is complete, i just wanted to increase bass output. it's really low
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Old 5th November 2009, 05:12 PM   #40
MJL21193 is offline MJL21193  Canada
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Quote:
Originally Posted by andrewskaterrr View Post
it is already sealed. basically the cab is complete, i just wanted to increase bass output. it's really low
You could EQ. Boost bass 100Hz and lower and you should have some room for that with the drivers Xmax and that box size. This requires more power though.
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