A Debate on the many different aspects of sound
02-20-2005, 05:04 AM
#112
500 Watt CAFz'r
Join Date: Oct 2004
Posts: 870
I have zero experience with ported doors, but I'm in the middle of a serious glass project on a 2000 Cavalier. The original plan was to put a pair of FPW-1200's in the trumk, and two 6's in the doors, and maybe 8's or 10;s in the rear sides.
I always thought that mixing sealed and ported causes too much phase shift and group delay, and we're trying to avoid having to have time alignment in this car. But the extra SPL of porting is tempting.
I could see some advantage of ported midbass, (lower excursion / higher mechanical power handling), but what is the trade off?
This car is being built more to show off, than as a pure SQ car, but I still want it to sound as good as I can get it, and I know it's going to be played hard.
Still can't find the procedure for measuring T/S of a driver...and of course no specs for the mids we're using.
I think I can squeeze at least a cu ft in the door enclosures.
Any thoughts?
I always thought that mixing sealed and ported causes too much phase shift and group delay, and we're trying to avoid having to have time alignment in this car. But the extra SPL of porting is tempting.
I could see some advantage of ported midbass, (lower excursion / higher mechanical power handling), but what is the trade off?
This car is being built more to show off, than as a pure SQ car, but I still want it to sound as good as I can get it, and I know it's going to be played hard.
Still can't find the procedure for measuring T/S of a driver...and of course no specs for the mids we're using.
I think I can squeeze at least a cu ft in the door enclosures.
Any thoughts?
02-20-2005, 08:35 AM
#113
500 Watt CAFz'r
Join Date: Oct 2004
Posts: 870
I found an on-line calculator...have to try it with a speaker with published specs and see how close it is.
http://www.bcae1.com/spboxad3.htm
http://www.bcae1.com/spboxad3.htm
02-20-2005, 08:56 AM
#114
Guest
Posts: n/a
port them, those that dicsount venting midbass/midrange on this forum have never done it themselves or ever bothered to experiment(if i am wrong correct me with your real world results) the speculation and opinions posed by these people are based on no actual testing. not every speaker will benefit most pratically everyone i have ever tested benefitted, some more that others but without parameters it can be difficlult, contact the menufacturer of the speakers, they should have them, then build a test box and actually try it you might be surpised
02-20-2005, 09:13 AM
#115
1000 Watt CAFz'r
Join Date: Oct 2003
Posts: 1,783
I've mentioned this before in some PMs, but I've found porting midrange drivers to affect more than just "deep" bass.
Even if you build just one box for one driver to try it out, I recomend trying a ported midrange driver playing from 500hz up. Make your own conclusions from that. Some drivers it may affect in a positive way, some not.
I don't think discounting an idea based on preconcieved notions of the possible benifits is very scientific. I'm not suggesting there's an absolute perfect approach to this, just that there are factors involved that convolute driver theory beyond the expected results.
I think everyone here can relate to practical experiences that made things work when theory could not.
Adam
Even if you build just one box for one driver to try it out, I recomend trying a ported midrange driver playing from 500hz up. Make your own conclusions from that. Some drivers it may affect in a positive way, some not.
I don't think discounting an idea based on preconcieved notions of the possible benifits is very scientific. I'm not suggesting there's an absolute perfect approach to this, just that there are factors involved that convolute driver theory beyond the expected results.
I think everyone here can relate to practical experiences that made things work when theory could not.
Adam
02-20-2005, 09:13 AM
#116
500 Watt CAFz'r
Join Date: Oct 2004
Posts: 870
Yep...the more I think about it, the more I want to do it. Any suggestions as to how to get a port into a small thin door panel? I guess I could just mould em outa glass, but maybe a quicker way.
I have the back and sides of the door panels moulded already...of course the back coutours to the door, so it's far from flat.
I have the back and sides of the door panels moulded already...of course the back coutours to the door, so it's far from flat.
02-20-2005, 09:19 AM
#117
1000 Watt CAFz'r
Join Date: Oct 2003
Posts: 1,783
I would not suggest using the factory door panel as any part of the driver enclosure or driver support. Having it fit on top of your fabricated enclosure is ok, but beware you are still going to transmit some energy from the driver/enclosure through the factory door panel. Even my heavily modified factory door panels vibrate to the touch.
I would suggest building a door pod that is mechanically isolated entirely from what's left of your factory door panel. That is the best case scenario, chose your own compromise.
Adam
I would suggest building a door pod that is mechanically isolated entirely from what's left of your factory door panel. That is the best case scenario, chose your own compromise.
Adam
02-20-2005, 09:55 AM
#118
Guest
Posts: n/a
Originally posted by defro13:
port them, those that dicsount venting midbass/midrange on this forum have never done it themselves or ever bothered to experiment(if i am wrong correct me with your real world results) the speculation and opinions posed by these people are based on no actual testing. not every speaker will benefit most pratically everyone i have ever tested benefitted, some more that others but without parameters it can be difficlult, contact the menufacturer of the speakers, they should have them, then build a test box and actually try it you might be surpised
port them, those that dicsount venting midbass/midrange on this forum have never done it themselves or ever bothered to experiment(if i am wrong correct me with your real world results) the speculation and opinions posed by these people are based on no actual testing. not every speaker will benefit most pratically everyone i have ever tested benefitted, some more that others but without parameters it can be difficlult, contact the menufacturer of the speakers, they should have them, then build a test box and actually try it you might be surpised
Y'know, I did install some tweeters in the AC vents once or twice back in the day and it sounded alright so I suppose I should promote that stellar install idea even though there are other ideas that are less effort for better results eh? [img]graemlins/thumb.gif[/img]
You haven't even offered a quantitative reason why a vented door is a better idea. All you have been able to offer is that "you like it".
What are you tuning these enclosures to?
What purpose are you trying to achieve?
How did that vent shooting at your hip bolster your front image?
My immediate reasoning for a vented door would be to bolster lower frequency response. But you run a front "woofer" as well that you laud the effects of so either that isn't the reason or it did not work for ****?
I have offered reasoning why it is a fruitless endeavor. How about you offer why it is worth the time and effort other than "it sounds good to me"
Oh yeah - token smiley since this is a friendly conversation: [img]smile.gif[/img]
02-20-2005, 10:00 AM
#119
500 Watt CAFz'r
Join Date: Oct 2004
Posts: 870
I'm cutting the bottom half of the OEM panel off and making a totally new bottom. I took a mould off the OEM panel to get the shape of the edge of the panel, and to get the moulded in factory screw insets...took a couple of tries before i got the mould to release clean off the new panel, but it turned out nice finally...I ended up priming and painting my mould, and covered it liberally with fluid film..waxed resin seems to be the trick too, as opposed to the laminating mix. My goal is to keep the inevitable layer of bondo to a minimum, and keep the weight down. Stock 2.2 under the hood.
Going to rebuild the rear sides as well....we just got a couple of racing seats in for the back seats, and we're making a new console to run all the way into the trunk
I'll post a pic or two tomorrow. This one's going to be another learning experience for me.
Going to rebuild the rear sides as well....we just got a couple of racing seats in for the back seats, and we're making a new console to run all the way into the trunk
I'll post a pic or two tomorrow. This one's going to be another learning experience for me.
