Audiophiles, Speaker lovers, lend me your ears! - PeachParts Mercedes-Benz Forum

JamesDean · #1 11-09-2010, 12:45 AM

Hey everyone,

I a subwoofer cabinet built based on a design from SpeakerPlans.com and am having some trouble:

Rather than retype, heres my original thread on their forum
http://forum.speakerplans.com/topic45069_post457464.html#457464

Any thoughts/comments/suggestions would be much appreciated!

Thanks

Kris

Stretch · #2 11-09-2010, 03:17 AM

I got the impression that your question revolves around the dust cap being on or off right?

A picture of the dust cap and the sealing of it would be helpful.

What is the frequency response of the speaker? Do you supply the speaker with an appropriately filtered signal - or are you just asking it to play everything between 20Hz and 20khz?

Generally speaking a small gap would influence high frequency response and large gap low frequency response.

Did you match the port characteristics to that of the box and your speaker? Or have you just bunged it all together?

Questions questions - sorry about that

francotirador · #3 11-09-2010, 08:28 AM

I'm also a bit perplexed by what your current problem is. However, there seems to be a lot of missing information. Did you build the cabinet to the dimensions required by the woofer? You certainly won't get the best response out of the speaker if it's not used in a cabinet built to correct specs. The manufacturer can provide you with optimal cabinet specifications for their speakers. I don't know how much knowledge/experience you have with car audio systems. The crossover point is also crucial. The amplifier is obviously also very important.

I've always built my cabinets to manufacturers specs and set the woofer in from the top after applying silicone around its lip. That makes for easy removal also. I never had any air seepage problems. The cabinets were bulletproof. I also always used high density fiberboard, not plywood as it tends to resonate.

I could go on and on here, but I don't want to write an article on how to construct auto subwoofer cabinets correctly.

Fulcrum525 · #4 11-09-2010, 08:59 AM

here you go

http://www.youtube.com/watch?v=sjjpbsUvggw

JamesDean · #5 11-09-2010, 11:44 AM

Quote:

Originally Posted by Army

I got the impression that your question revolves around the dust cap being on or off right?

A picture of the dust cap and the sealing of it would be helpful.

http://imgur.com/a/fU48k

Quote:

What is the frequency response of the speaker? Do you supply the speaker with an appropriately filtered signal - or are you just asking it to play everything between 20Hz and 20khz?

Driver is a Beyma 18G-50

Impedance 8 ohms
AES Power Rating 750 Watts
Program Power 1,500 Watts
Frequency Response 25Hz - 1.5kHz

Driver was powered by a Crown Microtech 2400 in bridged mono being fed signal by an Ashly XR series cross over between 50-100Hz. Cabinet is designed to handle up to 120 roughly.

Quote:

Generally speaking a small gap would influence high frequency response and large gap low frequency response.

Did you match the port characteristics to that of the box and your speaker? Or have you just bunged it all together?

Questions questions - sorry about that

Cabinet design is not mine, however it was designed with my specific driver as a possible component. I ensured that all the dimensions and specifications were held to as within 1% of the originals.

http://speakerplans.com/index.php?id=184sub is the design.

JamesDean · #6 11-09-2010, 11:57 AM

Quote:

Originally Posted by francotirador

I'm also a bit perplexed by what your current problem is. However, there seems to be a lot of missing information. Did you build the cabinet to the dimensions required by the woofer? You certainly won't get the best response out of the speaker if it's not used in a cabinet built to correct specs. The manufacturer can provide you with optimal cabinet specifications for their speakers. I don't know how much knowledge/experience you have with car audio systems. The crossover point is also crucial. The amplifier is obviously also very important.

I've always built my cabinets to manufacturers specs and set the woofer in from the top after applying silicone around its lip. That makes for easy removal also. I never had any air seepage problems. The cabinets were bulletproof. I also always used high density fiberboard, not plywood as it tends to resonate.

I could go on and on here, but I don't want to write an article on how to construct auto subwoofer cabinets correctly.

I used the designs according to speakerplans (link above).

Now, granted there were some design changes, the removable tray (hindsight says dumb) but at the time it seemed smart.

This cab was built from 18mm birch plywood, like all my other cabinets main cabinets. The others are MDF/Carpeted MDF.

JamesDean · #7 11-09-2010, 11:59 AM

One of the gents on the british board, and I didn't know this or even think of it, said that silicon fumes can eat away at a driver. I googled this and apparently it is so..

This makes sense as we had to silicon seal some of the joints last weekend and shortly after that the cover was off...

As is it now, the cabinet sounds impressive. throws bass everywhere, just like I want. I just hope the silicon fumes havent damaged the rest of it too much.

I've ordered some repair glue from PartsExpress and will reattach the dust cover in-cab...

Stretch · #8 11-09-2010, 12:53 PM

Err sorry but yet again I'm a bit confused - are you happy (for) now?

JamesDean · #9 11-09-2010, 01:16 PM

Its alright.

My primary concern is thus:
1) Dust cap has blown off, due to silicon fumes destroying glue
2) Cabinet now has air passage from upper to lower chamber
3) If i put the cap back on..which I must as it protects the coil/magnet gap...

I wonder how that will influence the sound of the cabinet...