Question for T3mpest

[rumblefish 10+ year member]

I just read your response to the gentleman not happy with the output of his SA12. You mentioned that with his box orientation he would have a dip around 60. I started a thread 2 days ago about my Starr Mountain enclosure. According to my imprint software, I have a huge dip around 60 as well. The subs are up but the port is back. It's bolted down, so it's not easy to just flip it. Just wondering if you think that could be the problem. Thanks.

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[T3mpest 10+ year member]

Almost certain it is. It it's a huge null right at 60 and nowhere else then that's likely what it is. Unbolt the box, face it rear and you dip should go away. Sub back port up generally doesn't have alot of ouput from the port though. If this does fix your 60hz problem, you may want to do another box with sub back port back or sub back port side. BTW, I was really suprised to see my name on the first page lol. Don't forget about using PM's.

 

[rumblefish 10+ year member]

Thanks for the response. I did try to use a PM but it said your box was full. That's why I started a thread.

 

[rumblefish 10+ year member]

I am curious as to why this is such a popular orientation if it causes cancellation at the stated frequencies .

 

[T3mpest 10+ year member]

Mainly because most people don't care. There are plently of car audio subs that can barely make it up to 60hz, or if they do, rolloff fairly hard after that regardless of how they are placed. Heavy coils, very stiff suspensions, low efficiency and usually nothing to control inductance to go along with all of it. Other main reason beyond that, and part of why subs are designed as they are, is because alot of people just want "groundpounders".. If the sub can play from around 30 to 45hz, they are happy. Not many people shoot for flat response so having a null where they tend to cross their woofers over at anyway isn't a big deal, especially if they aren't listening for it.

Lastly, sub up port back does eliminate alot of rattles in most vehicles. It seems better in that regard for distortion vs firing at the rear as you don't need to do as much work to deaden if you fire up.

 

[rumblefish 10+ year member]

Outstanding response sir. Thank you.