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Old 06-20-2013, 01:01 AM   #1
beanerman85

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Question Ported and reversed sealed sub on mono amp?

Hello peeps I am wondering if i hook up a 15" RE Audio SEx in a ported box and another one in a sealed box with the sub reversed to a mono block amp if it would make my system sound better, I know if i where to have the sealed sub forward facing would cancel everything out. I just wanna know, im thinking about trying it some time. Let me know your thoughts.
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Old 06-27-2013, 06:37 PM   #2
DjWheeze

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Keep them in the same type and size boxes or you will have sound issues.
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Old 06-29-2013, 06:12 AM   #3
beanerman85

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Quote:
Originally Posted by DjWheeze View Post
Keep them in the same type and size boxes or you will have sound issues.
Awesome thanks for the reply. I'll have to try it.
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Old 07-25-2013, 01:17 PM   #4
LoudOne

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Quote:
Originally Posted by DjWheeze View Post
Keep them in the same type and size boxes or you will have sound issues.
Not true...

if you know what you are doing you can build your box tuned to different frequencies and play a larger variety of music and have better response throughout the low frequency spectrum...

for instance... the proposed setup would work and depending on the box and would possibly work quite well... provided the box was built intelligently...

I have personally built boxes for 2+ subs and all chambers tuned to s different frequency...

The box proposed by the OP would allow the ported sub to hit the lower "boomy" notes and the sealed enclosure to nail the tight "punchy" notes... PROVIDED the box is built appropriately for the subs...and the power is there to move them.
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Old 07-25-2013, 02:38 PM   #5
basicxj

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Quote:
Originally Posted by LoudOne View Post
Not true...

if you know what you are doing you can build your box tuned to different frequencies and play a larger variety of music and have better response throughout the low frequency spectrum...

for instance... the proposed setup would work and depending on the box and would possibly work quite well... provided the box was built intelligently...

I have personally built boxes for 2+ subs and all chambers tuned to s different frequency...

The box proposed by the OP would allow the ported sub to hit the lower "boomy" notes and the sealed enclosure to nail the tight "punchy" notes... PROVIDED the box is built appropriately for the subs...and the power is there to move them.
I don't see the point of doing this (and risking peaky response or cancellation), especially when one properly designed enclosure will provide good response from 80hz on down to where human hearing rolls off. The labor involved in fixing the issues inherent to using two different enclosure designs together in one install will get you beyond the point of diminishing returns pretty quickly.

Most of the "punchy" part of response comes from your front stage when done correctly, and ideally you wouldn't have your subwoofer playing upwards of about 80hz so it blends with your front stage rather than being easily localized by the ear and standing out as a distinct source.
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Old 07-25-2013, 03:02 PM   #6
LoudOne

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You are correct to an extent basic, especially in regards to using the KISS method... I am far from an expert... but, peaky response is the reason for the different chambers for each sub...

we have all heard the system that bangs when the bass is down around 40-50 hz and when it gets up to about 80-100hz it rolls into about half of the SPL a the same volume simply becasue the enclosure is tuned at 45hz so you have a much more distinct peak at those frequencies...

I like to boom at the lower frequencies as much as the next guy... but I want to cover the full spectrum equally...

if you want to see how well your box performs download a sine wave and play it... it will make it painfully obvious were the peaks and valleys are.


Lets say you have a box with 4 subs... one tuned in at 35hz, another at 55, one at 75, then one sealed...

you would cover the peaks on your sub bass quite well then, however, you "may" have some bottoming out on the ones tuned to the higher frequencies right?
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Old 07-25-2013, 04:06 PM   #7
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Quote:
Originally Posted by LoudOne View Post
You are correct to an extent basic, especially in regards to using the KISS method... I am far from an expert... but, peaky response is the reason for the different chambers for each sub...

we have all heard the system that bangs when the bass is down around 40-50 hz and when it gets up to about 80-100hz it rolls into about half of the SPL a the same volume simply becasue the enclosure is tuned at 45hz so you have a much more distinct peak at those frequencies...
I won't say there aren't systems rolling around like that out there because there are, but a properly designed, installed and tuned system (by SQ/accuracy standards) with levels properly matched and phase issues taken care of won't have that problem. Choose and install equipment that can give you a response that is flat +/- 3db or so and there won't be a peak around 40-50hz and there won't be less output where your front stage takes over from the subwoofers .

Quote:
Originally Posted by LoudOne View Post
I like to boom at the lower frequencies as much as the next guy... but I want to cover the full spectrum equally...
Then there are far better approaches than using subwoofers in multiple, differing enclosures in such an install.

Quote:
Originally Posted by LoudOne View Post
if you want to see how well your box performs download a sine wave and play it... it will make it painfully obvious were the peaks and valleys are.
There are better tools for that- try some pink noise and a properly calibrated RTA. It will graphically depict output from 20hz to 20khz (the range where perfect human hearing can detect audio information) in your system and show each of those peaks and valleys...if you have done your system right, any peaks and valleys it exhibits will be so small as to not matter, as the ear will perceive it to be flat. With that said, many car audio enthusiasts do not value a flat response .

I'll repeat what I said in my earlier post, in that if your enclosure is properly designed (in this case for accurate, flat response) then there won't be large peaks and valleys in the system's response, especially if you have properly tuned that system and your subwoofers are level matched to the rest of the system. If the system is designed like most "street beater" systems you encounter, it will be far from flat.

Quote:
Originally Posted by LoudOne View Post
Lets say you have a box with 4 subs... one tuned in at 35hz, another at 55, one at 75, then one sealed...

you would cover the peaks on your sub bass quite well then, however, you "may" have some bottoming out on the ones tuned to the higher frequencies right?
That only takes part of the theory into consideration. I sincerely hope no-one would take the time to build such a setup for flat response...if fed an identical signal to each woofer, it would have a series of peaks all right (from constructive interference), where identical woofers in dissimilar enclosures that affect their response have output that combines where frequencies summing in-phase happen to overlap, but it would also have a series of voids in response and wasted energy where output from one woofer cancels with that from the next (destructive interference). The peaks and voids would measure much larger than just using an ideal sealed enclosure alone that is designed and adjusted for in-car flat response taking transfer function into consideration.

While it might seem like a good idea to you on paper, having subwoofers acting as mini-systems in their own right all playing the same signal with their resulting response altered by differing enclosures all playing into the same shared, enclosed listening environment, doing so won't result in a series of peaks that cover off all of the desired frequencies and amount to or sum to a flat response. When you take transfer function of the vehicle into consideration and how it reinforces a truly flat signal, the better approach would be to design a sealed enclosure that allows one or any number of identical woofers to work together towards that desired flat in-car response.

This isn't really the appropriate place on the forum to take posts in the product specific section so far off-topic. Start a thread over here on the topic:

http://www.caraudioforum.com/forumdisplay.php?f=38

...and we can continue the discussion when I don't have to go to work, and get some feedback from other experienced members who might not visit this section .
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Old 07-25-2013, 06:28 PM   #8
LoudOne

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basic... that was an excellent answer... I feel like I found Neo on the matrix...

will you be my new BFF???

now I have some serious questions for you...

Last edited by LoudOne; 07-26-2013 at 12:21 PM.
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