I think I am going to go with the W8-740P version. So now I need to decide how to insulate the box. I found that my local fabric store has a much broader set of insulation types, from poly-fiber to cotton. Now I just need to decide which and how much. Ideas?
Somehow this paragraph didn't make it into my past last night...
From some reading research, it seems the answer to how much is "try it and see". Most seem to pretty much fill the TL with insulation, but then "vary" it to get the right sound. The problem is there also seems to be the "speaker break-in period" problem. So getting the speaker to sound good "now", does not mean it will sound good "later".
Ideas on how to deal with this?
From some reading research, it seems the answer to how much is "try it and see". Most seem to pretty much fill the TL with insulation, but then "vary" it to get the right sound. The problem is there also seems to be the "speaker break-in period" problem. So getting the speaker to sound good "now", does not mean it will sound good "later".
Ideas on how to deal with this?
Your drawing shows more a MLTL with a very long vent, so personally would line the closed end, one side and back with 1" acoustical fiberglass insulation and damp the vent as required to quell any audible pipe harmonics, but most folks around here use polyfil, so stuffing the cab proper with around 0.3 lbs/ft^3 and add some as required in the vent tube.
Note that there was a thread not long about stuffing types IIRC, so do a 'loudspeakers' forum search to get more opinions. Seems that a shredded jeans? based product was very popular.
Well, I guess it might not be acceptable for some golden eared types that believe they can hear a slight tuning shift in the bass over time that typically occurs, but us mere mortals can't.
GM
Note that there was a thread not long about stuffing types IIRC, so do a 'loudspeakers' forum search to get more opinions. Seems that a shredded jeans? based product was very popular.
Well, I guess it might not be acceptable for some golden eared types that believe they can hear a slight tuning shift in the bass over time that typically occurs, but us mere mortals can't.
GM
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So what air speed in the "tube" section is low enough so I don't get any troubles with noise? Right now, my design has less than 2 m/s velocity max with 33 volts rms.
At all frequency's?
That's very low.
How long is the 'tube'? Watch out for port resonance.
I would stay under a meter / 3 feet
Staying below 14m/s is optimum but sometimes not possible.
That's very low.
How long is the 'tube'? Watch out for port resonance.
I would stay under a meter / 3 feet
Staying below 14m/s is optimum but sometimes not possible.
The "tube" is 8.5" x 2.7" x 37". I am using Hornresp to model the subwoofer. I thought that program took care of the port resonance thingy.
The program shows you the (sloth) port resonances, you have to take care of it by designing the tube (length) based on the results of the simulations.
Try keeping the ports first resonance well above the LPF frequency.
Try keeping the ports first resonance well above the LPF frequency.
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