Guys with JL Audio W7's come in
11-22-2005, 05:26 AM
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Guys with JL Audio W7's come in I just bought a 12W7 and I have a memphis 1000watt amp to power it. I was wonderin what everyone thinks of their subs and if oyu are running ported or sealed boxes. All teh W7s I have heard have been in ported boxes and from what I hear thats the only way to run one they dont sound good in sealed boxes supposedly. If you have a 12W7 how many watts are you pushin on it? Eventually I want to go to 3 12W7's once my new motor and trans is in. What is your overall opinion of it? Tryin to find a place in the Houston area to build a custom box for it. Does anyone have a box with atleast one fiberglass side. I dont know if any of you car guys have fiberglass boxes but for truck when buildign a box for under the rear seat there is hump in th emiddle that when building a custom box alot of builders build the bottom of the box out of fiberglass to hug the floor better for max airspace. I dont know if it changes the sound or not.
11-23-2005, 12:54 AM
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I dont have them but I have installed them.
I agree with the ported boxes sounding the best but I also dont like the sound of sealed boxes mainly because of cone double/wistle.
That sub can get really loud if you put the power to it.
Its much better to have the right sub, in the right airspace, with the right amount of power then it is to have more subs.
I would put at least 600+ watts on that 12W7
Heres a chart. Yours is the second one from the bottom.
I agree with the ported boxes sounding the best but I also dont like the sound of sealed boxes mainly because of cone double/wistle.
That sub can get really loud if you put the power to it.
Its much better to have the right sub, in the right airspace, with the right amount of power then it is to have more subs.
I would put at least 600+ watts on that 12W7
Heres a chart. Yours is the second one from the bottom.
11-23-2005, 10:30 AM
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Originally Posted by 1slow01Z71
I just bought a 12W7 and I have a memphis 1000watt amp to power it. I was wonderin what everyone thinks of their subs and if oyu are running ported or sealed boxes. All teh W7s I have heard have been in ported boxes and from what I hear thats the only way to run one they dont sound good in sealed boxes supposedly. If you have a 12W7 how many watts are you pushin on it? Eventually I want to go to 3 12W7's once my new motor and trans is in. What is your overall opinion of it? Tryin to find a place in the Houston area to build a custom box for it. Does anyone have a box with atleast one fiberglass side. I dont know if any of you car guys have fiberglass boxes but for truck when buildign a box for under the rear seat there is hump in th emiddle that when building a custom box alot of builders build the bottom of the box out of fiberglass to hug the floor better for max airspace. I dont know if it changes the sound or not.
11-24-2005, 09:51 AM
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that chart is totally inaccurate. manville smith himself told me that it is there to prevent unknowledgeable people from overpowering their subs. the 13w7 was tested to take over 10kw thermally and the W7 supposedly is impossible to bottom out. i have yet to see any W7 bottom out, but i'm not so sure that i believe it's impossible.
a W7 is actually designed to work well both ported or sealed. if you look at the Qts it indicates that it could easily go either way, and the EBP indicates the same. the W7 is a large xmax sub, so i personally enjoy using them in a sealed box to take advantage of that. that said, i always prefer ported simply for advantages in efficiency and the ability to easily net an anechoic response. so again, it's really either way.
a W7 is actually designed to work well both ported or sealed. if you look at the Qts it indicates that it could easily go either way, and the EBP indicates the same. the W7 is a large xmax sub, so i personally enjoy using them in a sealed box to take advantage of that. that said, i always prefer ported simply for advantages in efficiency and the ability to easily net an anechoic response. so again, it's really either way.
11-24-2005, 02:56 PM
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Originally Posted by Punk0Rama
that chart is totally inaccurate. manville smith himself told me that it is there to prevent unknowledgeable people from overpowering their subs. the 13w7 was tested to take over 10kw thermally and the W7 supposedly is impossible to bottom out. i have yet to see any W7 bottom out, but i'm not so sure that i believe it's impossible.
a W7 is actually designed to work well both ported or sealed. if you look at the Qts it indicates that it could easily go either way, and the EBP indicates the same. the W7 is a large xmax sub, so i personally enjoy using them in a sealed box to take advantage of that. that said, i always prefer ported simply for advantages in efficiency and the ability to easily net an anechoic response. so again, it's really either way.
a W7 is actually designed to work well both ported or sealed. if you look at the Qts it indicates that it could easily go either way, and the EBP indicates the same. the W7 is a large xmax sub, so i personally enjoy using them in a sealed box to take advantage of that. that said, i always prefer ported simply for advantages in efficiency and the ability to easily net an anechoic response. so again, it's really either way.
Come on, impossible to bottom out? I believe that almost any transducer can take 10k thermally for a few pico seconds, but I dont believe that no sub is unbreakable. You remember Orion XTR "unblowable" subs? They had ferriofluid that coated the voice coil and the bobin which was liquid iron that kept the temperatures down under high stress. The first day these subs came out I put a US Amps 2600 and blew the cone clear out of the basket.
You cannot look at just the Qts (electrical average of mechanical vs electrical resistance) and determine that the box is best suited for x application. There are ALOT of thiele-small parameters that determine this factor. Xmax is quite high on that subwoofer but again does not determine a sealed or ported enclosure. Xmax is simply the linear excursion of 1/2 pulse on a given frequency. Xmax is usually limited to the length of the voice-coil vs. the length of the gap and is only a measure of linear excursion.
11-24-2005, 03:14 PM
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Originally Posted by 2MuchRiceMakesMeSick
Come on, impossible to bottom out? I believe that almost any transducer can take 10k thermally for a few pico seconds, but I dont believe that no sub is unbreakable. You remember Orion XTR "unblowable" subs? They had ferriofluid that coated the voice coil and the bobin which was liquid iron that kept the temperatures down under high stress. The first day these subs came out I put a US Amps 2600 and blew the cone clear out of the basket.
Originally Posted by 2MuchRiceMakesMeSick
You cannot look at just the Qts (electrical average of mechanical vs electrical resistance) and determine that the box is best suited for x application. There are ALOT of thiele-small parameters that determine this factor. Xmax is quite high on that subwoofer but again does not determine a sealed or ported enclosure. Xmax is simply the linear excursion of 1/2 pulse on a given frequency. Xmax is usually limited to the length of the voice-coil vs. the length of the gap and is only a measure of linear excursion.
Qts = Qes*Qms/(Qes+Qms)
Qes = Re*Sqrt(Mms)/(BL^2*Sqrt(Cms))
Qms = Sqrt(Mms)/(Rms*Sqrt(Cms))
which other important t/s parameters are we needing to use?
i am fully aware of what xmax is. i will assume you are fairly familiar with xmax vs motor force. in a sealed enclosure, xmax is one of the most valuable considerations in terms of linear displacement. if you have a sub with low xmax, you will have limited output in a sealed enclosure. provided the motor force is of an acceptable value, it would perform much better in a ported enclosure where xmax is much less of a concern, particularly near tuning frequency.
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11-24-2005, 03:49 PM
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Originally Posted by Punk0Rama
not sure if you missed where i said i didn't believe that, but i never did say i believe that.
i am curious as to which other t/s parameters you use to make your decisions. consider this:
Qts = Qes*Qms/(Qes+Qms)
Qes = Re*Sqrt(Mms)/(BL^2*Sqrt(Cms))
Qms = Sqrt(Mms)/(Rms*Sqrt(Cms))
which other important t/s parameters are we needing to use?
i am curious as to which other t/s parameters you use to make your decisions. consider this:
Qts = Qes*Qms/(Qes+Qms)
Qes = Re*Sqrt(Mms)/(BL^2*Sqrt(Cms))
Qms = Sqrt(Mms)/(Rms*Sqrt(Cms))
which other important t/s parameters are we needing to use?
You just gave me the definition of Qts(average e vs m), Qes(electrical), and Qms (mechanical).
Thats great, I have those definitions but did you know those are speaker specific parameters.
We havent even begun to talk about any box parameters yet. You need a lot more then those three parameters when
calculating the box such as vas, fs. They derive a Vb which is used in many other calculations.
Box creation/tuning is much more complicated then three formulas.
Originally Posted by Punk0Rama
i am fully aware of what xmax is. i will assume you are fairly familiar with xmax vs motor force. in a sealed enclosure, xmax is one of the most valuable considerations in terms of linear displacement. if you have a sub with low xmax, you will have limited output in a sealed enclosure. provided the motor force is of an acceptable value, it would perform much better in a ported enclosure where xmax is much less of a concern, particularly near tuning frequency.
Yes I am quite aware but the xmax vs motor force but you make it sound as if they are the deciding factors. They do NOT determine the boxes destiny.
Although it may play a small role, there are many other important factors to consider.
When your limited on Xmax youll have limited output reguarless of the box. They use tuned/ported/ducted enclosures to gain +3db back.
11-24-2005, 04:01 PM
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Originally Posted by 2MuchRiceMakesMeSick
You just gave me the definition of Qts(average e vs m), Qes(electrical), and Qms (mechanical).
Thats great, I have those definitions but did you know those are speaker specific parameters.
We havent even begun to talk about any box parameters yet. You need a lot more then those three parameters when
calculating the box such as vas, fs. They derive a Vb which is used in many other calculations.
Box creation/tuning is much more complicated then three formulas.
Thats great, I have those definitions but did you know those are speaker specific parameters.
We havent even begun to talk about any box parameters yet. You need a lot more then those three parameters when
calculating the box such as vas, fs. They derive a Vb which is used in many other calculations.
Box creation/tuning is much more complicated then three formulas.
Originally Posted by 2MuchRiceMakesMeSick
When your limited on Xmax youll have limited output reguarless of the box. They use tuned/ported/ducted enclosures to gain +3db back.
11-24-2005, 07:27 PM
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I use to build boxes professionaly, many of them which went to iasca db drag and outlaw classes, so I would consider myself as part of that "crowd". You have good theory but its just a little more involved then three parameters.
Back on topic...
Which amp do you have?
MC1000D or PR1KD
Back on topic...
Which amp do you have?
MC1000D or PR1KD
11-24-2005, 08:00 PM
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in order to calculate Qts, you need every other parameter. that means that every other parameter is considered in Qts. your argument is that it is inaccurate because there are more parameters involved. i agree that there are more involved, but they are included in the parameter Qts. i have no doubt you built db drag enclosures. but i think you are the first person i have ever talked to from that crowd who has stated that Qts is not accurate in determining a particular enclosure.
11-25-2005, 09:07 AM
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the jackhammer is a useless, impractical sub. if you took a RE MT with the same amount of power, you could beat it quite easily in an spl comp and they would sound close to the same for daily driving.
11-26-2005, 01:23 AM
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Jackhammer is more of a marketing gimmick then anything.
Heres 8500 watts on that sub to get a WHOPPING 130 decibels
http://www.nearlygood.com/files432666/mtxjackhammer.wmv
Heres 8500 watts on that sub to get a WHOPPING 130 decibels
http://www.nearlygood.com/files432666/mtxjackhammer.wmv
11-26-2005, 12:56 PM
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i just took out 2 L7 kickers out of my 04 ZO6 (sealed enclosure) and put in one 10W7 in a ported box (used specs from JL website) and it hammers way harder and lower than it did before. i am still using the same amp, phoinex gold XS2500.
11-27-2005, 09:02 AM
#17
Hey, i have a 12W7 in a custom ported box to JL specs and i absolutely love it. I have 3 10's in the back before sealed and this sub blows them away in SPL and DEFINATELY in SQ. To me, SQ suffers in the proted box, but these subs are so clean, u really cant tell a difference wiht a ported box. Get a ported box and trust me u wont be dissappointed. Also, i am pushing about 825-850 watts to it so shes welll powered. 
11-27-2005, 09:04 AM
#18
https://ls1tech.com/forums/wiring-stereo-electronics/375149-show-your-sub-amp-setup.html scroll about halfway down the page and look for my post with 2 attacthed pictures, that should give u a pretty good idea.
