A Debate on the many different aspects of sound
02-02-2005, 01:27 PM
#31
Yankee
Join Date: Oct 2003
Posts: 3,599
I think the point everyone is dancing around is control. We usually talk about processors controlling the sound but this thread is about how we control the back wave or more accurately the entire performance of the midbass driver. This answer SHOULD be unique to the driver (speaker) and vehicle. Some speakers will benefit by sealing up the door some will not, and the benifit may not be due to better frequency responce, but due to isolating the driver from the door. I think the goal here is to put together a system that allows the speaker/ amplifier combo to perform at its highest level (to me this could provide more benefit than TA or EQ). I have been using a sealed box for my midbass but I have recently vented it and have found the performance much more dynamic/ punchier. This midbass is removed from my door because I could not get rid of all my door rattles and I was just not happy with the ragged freq responce from that driver in my door
[ February 02, 2005, 08:48 PM: Message edited by: JohnVroom ]
[ February 02, 2005, 08:48 PM: Message edited by: JohnVroom ]
02-02-2005, 02:01 PM
#32
Guest
Posts: n/a
[quote]
The beauty of F1 is the quality is so high you need less processing to make it sound right.
[quote]
If one needed a $5000 processor to correct for how the gear sounds then they should look at different gear...
As for doors... (you knew the opinion was coming.)
First I totally agree with Fattywack that the driver should be used as it was designed to be used. If one is fortunate to have the t/s specs and understands how to use them then that's great. I also agree that most caraudio mids are not designed for a box at all, let alone a vented one. I would even suggest that 'car audio' mids that spec out for vented boxes are merely reborn home audio mids with 4ohm coils.
Next I would have to wonder on the reasoning behind venting a door midrange/midbass when vented subwoofer boxes are so looked down upon in the SQ world. I prefer a vented subwoofer to enhance and accentuate a particular range of sound. Then I cut off the response of the driver shortly above that range. Basically the net is that I have added gain to the woofer's entire range of play. Free output if you will.
Now, since a midbass or midrange usually operates over a much larger range I don't see why one would want to accentuate part of that range. Seems to me that if one has a multichannel system and wants to blend in their midbass to their subwoofers that gain matching would be an easier method.
To recap - use the particular driver properly.
The beauty of F1 is the quality is so high you need less processing to make it sound right.
[quote]
If one needed a $5000 processor to correct for how the gear sounds then they should look at different gear...
As for doors... (you knew the opinion was coming.)
First I totally agree with Fattywack that the driver should be used as it was designed to be used. If one is fortunate to have the t/s specs and understands how to use them then that's great. I also agree that most caraudio mids are not designed for a box at all, let alone a vented one. I would even suggest that 'car audio' mids that spec out for vented boxes are merely reborn home audio mids with 4ohm coils.
Next I would have to wonder on the reasoning behind venting a door midrange/midbass when vented subwoofer boxes are so looked down upon in the SQ world. I prefer a vented subwoofer to enhance and accentuate a particular range of sound. Then I cut off the response of the driver shortly above that range. Basically the net is that I have added gain to the woofer's entire range of play. Free output if you will.
Now, since a midbass or midrange usually operates over a much larger range I don't see why one would want to accentuate part of that range. Seems to me that if one has a multichannel system and wants to blend in their midbass to their subwoofers that gain matching would be an easier method.
To recap - use the particular driver properly.
02-02-2005, 02:41 PM
#33
Guest
Posts: n/a
i sort of agree with dukk, the speakers should suit the enclosure, but more above average quality spekers will benefit from venting than those that wont, i never said that all speakers will benefit, but many will. venting mids is the furthest thing from being frowned upon, but many times its not possible due to vehicle limitations. i was very fortunate to have the benefit of a legnthy discussion with one af the alpine led engineers behind f#1 in las vegas this year and he enlightened me on this exact subject and why its makes sense to vent if possible. the first and foremost reson was the low freq excursion limiting of the vented box with proper x-over, the benefits of that which im sure that we dont have to argue that point, as well as the harmonic advantages a vented midrange/midbass box over particularily the ib set up, and dukk the idea of venting a midrange isnt to accentuate a freqency range but rather to extend the low frequency capabilities of a speaker without accentuating a particular frequncy. maybe rather than discredit it, why doent everyone do a little experiment, take a good set of speakers that you can get some decent parameters for, and build some vented boxes for them. contact the manufacturer if you want to get a idea for a correct box, build it and listen to it both vented and sealed and draw your own conclusions, i have yet to hear even 1 set of speakers that didnt benefit from venting and ive built alot of boxes for alot of different speakersuch as , eton4", every avi ever built practically, focal 5.25", focal 7", davis acoustics 6.5", ads 325is(old) pg zeropoint 5.25" and 6.5", alpine f#1 6", kef uniq 6.5", a ton of vifa speakers, all of these over the last 10 years, so im talking without experience. i hope some of you take the time to experiment, i would like to hear your conclusions
02-02-2005, 02:57 PM
#34
Guest
Posts: n/a
My opinion is that it is easier to put a sub up front than to build vented enclosures in the doors. My favorite bookshelf speakers also are vented, but they are very different drivers in a totally different environment than a car. If you want to go through the trouble of venting your frontmids, by all means go ahead. It's not a terrible idea, but seems like a ordeal that will take more time than other ideas that will have a better effect. And if you say that you have all the time in the world, then I say bust out the plasma cutter and put a ten up front.
02-02-2005, 05:36 PM
#36
Guest
Posts: n/a
^ For sure a vented box extends the lower range of the mid. This is great if there is no driver to fill in the bottom couple of octaves. This is not the case in car audio where 99% of the time a subwoofer is present in the system.
Yes, most of the time the sub is in the back and we are not.
Like Dereck, I am just not of the opinion that the work required for vented doors has enough repayment for me. I do not hold the 'cost and time is no object' attitude. I have very limited time to work on my car so I have to put it where I think it does the most good.
Even so, I am just not convinced that the mid needs the bottom end response reinforcement that a vented box offers when a sub is there to provide that range already.
Yes, most of the time the sub is in the back and we are not.
Like Dereck, I am just not of the opinion that the work required for vented doors has enough repayment for me. I do not hold the 'cost and time is no object' attitude. I have very limited time to work on my car so I have to put it where I think it does the most good.
Even so, I am just not convinced that the mid needs the bottom end response reinforcement that a vented box offers when a sub is there to provide that range already.
02-02-2005, 06:08 PM
#37
Guest
Posts: n/a
i guess one of these days i hope you will get the chance to try it. then again i dont believe that you can get up front bass with woofers in the back so getting as much controlled deep bass from my midbass is critical for me in achieveing good up front bass, something that i have never heard done with rear woofers. i always like this discussion, its fun and makes people think, wanna talk about cost justification or processing now 
02-02-2005, 08:03 PM
#38
1000 Watt CAFz'r
Join Date: Oct 2003
Posts: 1,783
"Fattywhack" LMFAO!!
For my car, it's easier to vent the doors than put a sub up front.
People are refering to drivers having parameters that allow for porting. For all the NOOBs, it would be nice if someone were to spell that out in terms of a Qts # for example.
Adam
For my car, it's easier to vent the doors than put a sub up front.
People are refering to drivers having parameters that allow for porting. For all the NOOBs, it would be nice if someone were to spell that out in terms of a Qts # for example.
Adam
02-03-2005, 06:22 AM
#39
I modeled my mids/midbass before I built any enclosure... the mid range went in like .25cubes with a QTS of around 1.2 and should play flat down to 300hz (hardly ideal for a midbass- these things need 1cube or more!)
Anyway.. the two pair of midbass are sort of vented in that the back of the enclosure has a hole opened up to the rest of the area inside the door... I have no idea how it will effect sound, but I think I can consider them more/less IB....
Its pretty clear why some kickpanels lack alot of midbass.... people use the wrong drivers for such a tiney enclosure !!!
Anyway.. the two pair of midbass are sort of vented in that the back of the enclosure has a hole opened up to the rest of the area inside the door... I have no idea how it will effect sound, but I think I can consider them more/less IB....
Its pretty clear why some kickpanels lack alot of midbass.... people use the wrong drivers for such a tiney enclosure !!!
02-03-2005, 07:12 AM
#40
Guest
Posts: n/a
basic ts parameters explained
fs - the resonant frequncy of a speaker, everything that moves vibrates, everything that vibrates has a frqeuncy that it will vibrate at the most efficiently, that being the fs
re - the dc resistance of the voice coil
qms - the mechanical resonance at fs
qes - the electrical resonance at fs
qts - the total combined resonanace at fs
mms - the mass(weight)of the speaker compponents(not magnet or frame), ie, surround,cone, voice coil, former etc
xmax - the maximum linear excursion of a speaker in 1 direction
these are the basic parameters that are used when designing most boxes, therea re far amore parameters that can be used but these are the basic ones
fs - the resonant frequncy of a speaker, everything that moves vibrates, everything that vibrates has a frqeuncy that it will vibrate at the most efficiently, that being the fs
re - the dc resistance of the voice coil
qms - the mechanical resonance at fs
qes - the electrical resonance at fs
qts - the total combined resonanace at fs
mms - the mass(weight)of the speaker compponents(not magnet or frame), ie, surround,cone, voice coil, former etc
xmax - the maximum linear excursion of a speaker in 1 direction
these are the basic parameters that are used when designing most boxes, therea re far amore parameters that can be used but these are the basic ones
