Hey guys I've come to you once again for some advice. I'm ready to experiment with a bigger sub and box combo for more SPL. I'm currently running a 12W7 in a tuned enclosure to 32Hz installed and tuned under the guidance of the All Mighty Swez. Although this set up sounds good and amazing to most people that have heard it, I need much more SPL without the addition of another 1000/1 and all at upgrades that go along.
I'm looking for a 15" sub to run with my JL 1000/1 that will easily outperform the 12W7 while maintaining sound quality.
I have been looking hard at the Powerbass Xtreme 3XL 15 which would fit the budget of around $550 including $200 for a custom built tuned enclosure. I woul appreciate your advice in chosing a driver to reach my goal.
http://www.powerbassusa.com/products/subwoofers/3xl_subwoofers.html
also have been looking at these Fi subs mentioned by I believe 30Hz specifically the Q series.
https://ssl.perfora.net/www.ficaraudio.com/sess/utn;jsessionid=15462433d15645b/shopdata/0020_Q/product_overview.shopscript
All commentsand suggestions are greatly appreciated.
Demetrios
Replies (29)
trunkisloud on 04/16/2007 23:03:25
man i wish i had deep pockets....theres a wide array of 15's you can get in that range......and good ones at that...im personally a street beater...i like to be really loud and obnoxious so i could name a few speakers to fit that bill..as far as sq, you might wanna talk to others..im not too keen on that dept.
demetman on 04/16/2007 23:08:52
Well the 12W7 actually pumps out some impressive SPL with the JL1000/1 in my fully sound deadened vehicle. I would like the optoin to bang down the streets when I'm feelin it. What doyou think of the 2 subs I listed as potentials?
trunkisloud on 04/16/2007 23:35:24
those look like some nice ones....never heard em before but the specs look good.
swez on 04/16/2007 23:39:12
Well it's good to see ya back Dem and, thanks for th kind remarks... but you did the hard part sir. (My hat is off to you too)
It seems to me that a very efficient sub and enclsoure wouold be the next logical step. Yes, the W7 is a great SQL sub, but not as efficient as some other options. Also, a 15'" sub is often a few dB more efficient and can really put out the deep lows when mated to a well designed enclosure.
The crux of the issue is that it sound like you want an SPL sub that sounds as clean as the W7, but more umph w/o adding more power amps. I like that plan and 1000 Wrms is nothing to sneeze at for a good SLP/SQL sub.
OK, it's research time for now. But on the other side of the equation, it would be great to have a reference point as well. (Meaning, get your present bass engine tested for SPL in this Magnum.) Let's find out how much dB of SPL you are getting now and then figure out a way to squeeze a 3-5 dB increase w/o losing SQ performance too. Can you get this car miked for a ref point? (What's the SPL #'s you are getting now?)
Once we have that established, then press on to seach for a super efficient woofer system that will get ya there w/o adding more amping power.
Do you agree with this plan of attack?
Swez
cplkittle on 04/16/2007 23:55:47
I would think that more of the same (multiple W7s) would be better than mixing it up with different sizes.
demetman on 04/17/2007 00:14:49
kit I plan on removing the 12W7 and enclosure all together and start fresh with a larger 15" sub that has a better sens rating and will optimally perform with my 1000/1 amp. this is more so an experiment to achieve more SPL by replacing the 12W7 in it's enclosure. It will go to the basement before I decide it's fate or resorection. I am simply looking for a 15" driver and optimum enclosure tuned for my vehicle.
Swez, I will look into getting an SPL reading fo the current set up. Would I need to go to an audio shop for a meater reading? I am aware that one can't achieve SQ and SPL so I'm willing to give up some SQL for SPL. Thanks,I'd like to get this project started asap while the funds are available.
Demetrios
30Hertz on 04/17/2007 03:39:31
As far as Fi goes, the Q series is more of the Sq series sub. If your going for SPL, look at the BTL and fully load that sucker!
Also take a look at the Stereo Integrity Magnum D2, They get loud, low and clean also!
demetman on 04/17/2007 09:59:00
Swez I'm having a hard time finding an audio shop that has an SPL meter. The only shop that has a meter is the shop that destroyed an install in a previous vehicle and ripped me off big time. Needless to say I won't be stopping by there. There has been a few privatelly owned shops close down as well as Tweeter Center in the past few months. Is there a way we could move foreward with this project without an SPL reading?
30Hertz, the BTL series Fi sub looks like one bad sub, however I only have a 1000/1 available for power. This sub wants at least 2000Wrms to get it started. I keep refering to the Powerbass 3X do to the 93dB sensativity rating. My 12w7 gets pretty loud but I need to really crank up the volume to get it going, hence the 86dB sens rating.
D
30Hertz on 04/17/2007 14:06:36
Yah I kinda overlooked the minor issue of power here haha. The BTL is a beast, and I'm getting one sometime in the future. One of the guys I know has a single 12 throwing up 151dB on the TermLab but he's pumping about 3000watts do it. (still not that much power for the dB drags). Most guys I know are running 8kw of power on two 15"s.
As far as the sensativity rating, yes the Powerbass 3x has a higher rating, but the 12w7 is a better build quality. Usually woofers with a high BI (motor strength) have a lower overall sensativity rating. I cant say much about the Powerbass since I havent personally ran it. Looks like a stout sub so either one would work.
As far as a SPL Meter, where are you from? Depending on your location I might be able to make some calls and see if I can set up a meter for you.
30
ShootuhMcBustaCap on 04/17/2007 21:20:52
Dem, don't feel too bad, I cant find anywhere do get my whip SPL tested either.
I had typed up two long replies, complete with tons of model reccommendations, but I lost both of them right before I finished. I wanted to ask before I did all of that again, are you totally with the single driver solution, or would consider a multi driver setup? This way you could run a pair of 15's 12's or even 10's to increase SPL, or keep SQL at an optimum setup. With a 1000/1 there really is endless possibilities of sub combinations
I really like the looks and specs of the Fi Q series. I could definitely hang with one of their beastly looking 18's fully optioned at $340.
cplkittle on 04/17/2007 21:25:40
I have installed a few powerbass 3x systems.. all 10's and 12's though. I was REALLY impressed with their performance, and they are still thumping 6-8 months later. They can take some abuse.
demetman on 04/17/2007 22:31:41
A 15" 3XL looks like it requires a 5cf ported enclosure for peak performance. When you guys look at the parameters, is this true? Do you guys think I will achieve a 3-5dB increase in SPL over the 12W7 using this driver? If I only knew that a 13W7 can move 39% more air than the 12W7 at time of purchase I wouldn't be in a situation to shell out $500 more bucks for a little more bass.
http://www.stereointegrity.com/Magnum12.html
This sub looks like a potential winner and fits the power requirements well. The only concern at an ameture glance is the lower X-max of 27mm compared to the 29mm of X-max of the W7.
Maybe the larger cone area would make up for the smaller degree of linear travel capacity of this sub.
30Hz I live in Mays Landing New Jersey just outside of Atlantic City. There really isn't many mobile audio shops in my area as car audio seems to be fading these days. One Stop Car Audio does have an SPL meter but they hacked my vehicle to hell and back on a previous install and I wouldn't even step foot in that place to use their bathroom.
Any ideas guys?
30Hertz on 04/17/2007 22:40:10
Do keep in mind that Xmax isnt a sole indicator of the subs ability to get loud. It helps yes, but your not going to notice a 2mm difference from 27 to 29mm =). Some of the subs you see at the dB drags are hitting huge numbers with a low XmaX sub. Why? Because their burping at higher Hz, doesnt require such a long throw since the sine wave is not as long.
IF you like the D2, Id say go with it! Their a solid sub with proven performance not only as a Daily Driver, but at comps also.
I know a guy that was hitting huge numbers with the SI mag D2 and personally, I would like to run one at some point or another but I've got my eye fixed on a BTL.
Let me see if I can find anyone around that area. Most of the guys I know live in SC, Indiana and some of the other states.
30
swez on 04/18/2007 16:13:22
The SI Mag D2 smacks of the RE designs we are all used to seeing today, but with a few minor mods. As Hertz mentioned, this sub has a few mm of extra excursion and a slight edge in SPL, (1w/1m) over the W7. Power handling is good as is BL and Fs. The box needs are not too unmanagble either.
I have been off on other projects of late and just have not had much time for searching things down like before. In this case, a true 92 - 95 dB of SPL @ 1w/1m from a very reputable sub maker would be an great option at the power level in that amp.
Also, knowing what kind of SPL is coming from your present system would be a good benchmark to know. A 2-3dB bump would be OK, but if we can figure out a way to land you a solid 5-6 dB more, that's gotta be something you would be happy with. The "Wicked One" enclosure is a great design for HT and very large vehicles, but the weight and size of this design would be an issue to consider carefully before diving in. (Using the W7 too)
Another option to consider is a well designed BP enclosure. However, these are best for SPL apps and do not give enough bass range to be considered a serious SQ/SQL sub design. Yes, they are indeed efficient, but of limited use to the SQL guy.
Am still thinking that a more efficient enclosure that does not greatly degrade SQL but gives medium-efficiency subs a few exta dB of SPL would be worth some research time. the question is where to look for such things and then figure out how to make it fit in your Magnum too.
Will ponder and look about as time permits and see what makes the most sense. If I find something of real interest, will come back to ya.
Swez
demetman on 04/18/2007 22:59:07
Sounds good Swez. Just to clarify, the Magnum D2 has less Xmax(27mm) than the 12W7(29mm). I won't purchase anything until we can determine a definate increase in SPL over the 12W7. Let me know if you find a potential product. If anyone has any places for me to search drivers for a high sens rating and power handeling to suit my needs let me know. I think 1-15" driver in a tuned enclosure is the way to go. Thanks
D
demetman on 04/23/2007 20:27:37
Ok I'm pretty convinced that the W7 is the indisputed king of SQ/SPL subs based on research, personal experience and the lack of any potential contenders from this broad base of very talented audio enthusiasts.
What do you guys think about upgrading to a 13W7 w/a custom tuned enclosure to reccomended specs? What kind of increase in SPL would likely be achieved from this larger more powerful driver. I already have a potential buyer for my 12W7 so this upgrade could very well fit the $500 budget. The JL specs show this driver capable of moving 39% more air, 4mm more Xmax than a 12W7 and 1000Wrms is optimum performance power for this sub. Do you guys think I would be happy with this set up? Thanks
D
cplkittle on 04/23/2007 21:09:53
I have never met a customer that was unhappy with a 13W7 and a 1000/1.
I think it is possible to at least double the output over a 12W7, especially if the enclosure is properly designed and constructed.
swez on 04/23/2007 21:17:21
Why would that be Kittle? Do you have any SPL numbers from both subs as a comparison?
Am sure the 13W7 is a premium sub in all respects. (It should be for the money) But why the extra bump? It's efficiency is about the same as the 12W7, but cone area is larger so it can move more air. The "no" of the 13W is also a tad more efficient too.
Any other thoughts?
Swez
cplkittle on 04/23/2007 21:31:40
Just an educated guess...
13W7
32mm xmax 107.35 sq in surface area 1000 watts
12W7
29mm xmax 84 sq in surface area 750 watts
Difference:
4mm Xmax
23.35 sq in more surface area
+250 watts
demetman on 04/24/2007 16:57:00
Wow, it's hard to believe a 13W7 could outperform a 12W7 to a substancial degree of output utelizing the same amount of power and same enclosure design! What does the above equasion(and I know it is a hypothesis) equate to in Db reference? When you say the right enclosure are you refering to a JL reccomended tuned enclosure of 2.375cf with a slot port tuned to 30Hz? Some manufacturers show a couple different ported enclosure specifications to yeild different result sin SPL/SQ. JL's port recommendations are derived through actual tests and measurements, not computer simulations and they only show one reccomended ported enclosure per sub. May be getting close to closure here. Thanks for the info.
D
cplkittle on 04/24/2007 21:11:22
5 posts ago you said you were building a custom enclosure to specs. The enclosure will have alot to do with the sound. Using the same enclosure may not yield the same results.
JL audio will work with you personally if you call them and ask what enclosure is best for your vehicle. I have called them several times in the past for recommended enclosure sizes for different vehicles.
I know +3dB seems like a stretch, but having worked with both the 12 and the 13w7, I do believe it is realistically achievable.
swez on 04/24/2007 22:08:56
The question I would put on JL tech's, How much of a difference in SPL would I likely see with a 12W7 vs a 13W7 in an optimal ported box and 1000 RMS to either sub?
If they say +3dB or more with the 13W7, it's worth a closer look.
Swez
demetman on 04/24/2007 22:35:27
Yes cplkittle I did say an enclosure would be built to exactly JL's specs, as I am aware of how crucial this is. A JL authorized dealer and a small shop owner in business over 15 yrs crafting quality custom boxes made my 12W7 enclosure and that is the only way I would go for a 13W7. I don't cut corners and don't trust my abilities to craft a tuned enclosure for such an expensive product.
The reason I am here probing for info is because JL will sugar coat all results of product output! I was originally planning to add another 12W7 to my set up because after consulting JL (Hector) I was told an increase in at least +3 to +6 dB would definatelly be achieved. I then came to this board asking for your opinions and was advised that no additional increase in SPL would be achieved splitting the 1000w to each driver.(Swez you remember this topic a bit back). Of course they want me to believe I will double my output they want my $700. They also advised me to dump the a/d/s/ comps I have and purchase the ZX comps for better MB perormance(another issue I had and resolved). Forgive me for being a PITA but I don't like to make rash decisions and always research investments to the fullest extent. These things aren't cheap!
D
cplkittle on 04/25/2007 00:04:11
I don't blame you at all for researching this, especially where close to $1,000 is involved.
All I can offer is an opinion. I have never metered the differences of a single 12w7 vs a single 13w7. I have heard both as singles, but for a true comparison, they would have to be metered in identical vehicles under strict conditions.
I am sure it is safe to assume the 1000/1 was tuned properly when this setup was installed. The settings will be different with the 13w7. (gain should increase as power handling is 250 watts more, and SS could possibly be dropped a few Hz).
I guess I should have been more vague and noted that a 3dB increase was an opinion, not a fact. I do firmly believe that you will notice a significant difference between the two subs.
swez on 04/25/2007 09:28:25
Right... some hard numbers are needed here to determine which direction to take.
See, I have worked with Dem at length on this project and have taken a position of ownership on the outcome. Meaning, "If I had this situation, knew all the key parameters and have already hit the SPL wall limits with current gear, what would I do with a given budget?" I would not shoot a wad of cash and "hope" it's better.
Also, the electrical system is pretty well maxed out now too. Adding another 1000 watts and a matching sub would help. But the overall cost of doing so is pretty high for such a minor increase. (~3dB more bass?)
This is why we are looking at a single HO sub that can deliver a solid +6dB more bass at 1000 watts. At this point, "guessing and hoping" are not a good option with the expense that is on the table already.
Dem, would it be possible to demo your 12W7 vs a 13W7 at the shop you have been doing buisness with? If they have a 13W7 and ported box on hand, that would give a better idea what to do next. Other than that, we are fishing in an unknown pool.
Swez
demetman on 04/25/2007 10:38:31
Ok guys I called JL this morning, explained what I was looking for and asked for their opinion. The tech I spoke to explained that adding a 2nd 12W7 in a ported enclosure is the most effective way to achieve a higher SPL using the same power. His quote was "There's no repacement for displacement" and calculated the difference in cone area from a single 12W7 to 2 12W7's and a 13W7.
A trip to the JL dealer is in line and maybe some questions can be answered there. I'll let you guys know what I find out.
D
cplkittle on 04/25/2007 12:13:52
There is no replacement for displacement, but if the displacement of one 12w7 is handicapped ( xmax cut in half due to splitting the power) is anything gained? If another amplifier is added along with another sub, I could see an increase, but dividing the power between the two subs? I don't see an increase there.
I'm just trying to play devil's advocate to hit this from all angles.
swez on 04/25/2007 15:57:10
Well, am wondering if there is a hidden bug in the system. Thinking about "Thermal Compression", (TC) as a possible culprit here???
TC is when the coils are fed lots of watts over an extended period of time and then the coils retain heat and the resistance goes up after a few minutes of heavy thumping and bass SPL drops as resistance goes up in the coils.
Tech Tip: We may be able to detect this in action too.
1. Measure the coil resistace with an ohmeter when cold and record the results
2. Then reconnect sub and let it work at high power for say 15-30 minutes
3. Quickly disconnect the sub wires and measure ohmic again
If the hot coil measurements are notably higher than when measure when cold, this is what is bringing down your sub SPL levels. When coil wires heat up, (the voice coils are very fine wires on a bobbin) they increase in resistance. If that coil set was like 2.5 ohms when cold and is now well over 5 ohms, that would explain a drop in power over time.
In some cases, we may hear a drop in power due to TC issues. An SPL meter can easily confirm it too. I cannot help but wonder if this would explain a loss in bass SPL after the sub warms up.
Basically, it goes like this:
1. On a cold sub, it sounds tight and robust
2. As the coils heat up, the coil resistance goes up
3. As the resistance goes up, SPL output drops in proportion to resistance changes
Anyone else got another possible explaination?
Swez
swez on 04/25/2007 16:12:50
Hey, a very good read for SPL/SQL sub users. Have a close look and mull it over.
This is a neat idea for more efficient cooling of the sub coils. Yes, it takes a machine shop to fabricate the cooling plug, but the idea has merit. Have a look:
http://www.audioroundtable.com/PiSpeakers/messages/17535.html
As long as the ported cooling holes are large enough and do not add any whistle effect noises, the idea makes very good sense huh?
Swez
I'm looking for a 15" sub to run with my JL 1000/1 that will easily outperform the 12W7 while maintaining sound quality.
I have been looking hard at the Powerbass Xtreme 3XL 15 which would fit the budget of around $550 including $200 for a custom built tuned enclosure. I woul appreciate your advice in chosing a driver to reach my goal.
http://www.powerbassusa.com/products/subwoofers/3xl_subwoofers.html
also have been looking at these Fi subs mentioned by I believe 30Hz specifically the Q series.
https://ssl.perfora.net/www.ficaraudio.com/sess/utn;jsessionid=15462433d15645b/shopdata/0020_Q/product_overview.shopscript
All commentsand suggestions are greatly appreciated.
Demetrios
Replies (29)
trunkisloud on 04/16/2007 23:03:25
man i wish i had deep pockets....theres a wide array of 15's you can get in that range......and good ones at that...im personally a street beater...i like to be really loud and obnoxious so i could name a few speakers to fit that bill..as far as sq, you might wanna talk to others..im not too keen on that dept.
demetman on 04/16/2007 23:08:52
Well the 12W7 actually pumps out some impressive SPL with the JL1000/1 in my fully sound deadened vehicle. I would like the optoin to bang down the streets when I'm feelin it. What doyou think of the 2 subs I listed as potentials?
trunkisloud on 04/16/2007 23:35:24
those look like some nice ones....never heard em before but the specs look good.
swez on 04/16/2007 23:39:12
Well it's good to see ya back Dem and, thanks for th kind remarks... but you did the hard part sir. (My hat is off to you too)
It seems to me that a very efficient sub and enclsoure wouold be the next logical step. Yes, the W7 is a great SQL sub, but not as efficient as some other options. Also, a 15'" sub is often a few dB more efficient and can really put out the deep lows when mated to a well designed enclosure.
The crux of the issue is that it sound like you want an SPL sub that sounds as clean as the W7, but more umph w/o adding more power amps. I like that plan and 1000 Wrms is nothing to sneeze at for a good SLP/SQL sub.
OK, it's research time for now. But on the other side of the equation, it would be great to have a reference point as well. (Meaning, get your present bass engine tested for SPL in this Magnum.) Let's find out how much dB of SPL you are getting now and then figure out a way to squeeze a 3-5 dB increase w/o losing SQ performance too. Can you get this car miked for a ref point? (What's the SPL #'s you are getting now?)
Once we have that established, then press on to seach for a super efficient woofer system that will get ya there w/o adding more amping power.
Do you agree with this plan of attack?
Swez
cplkittle on 04/16/2007 23:55:47
I would think that more of the same (multiple W7s) would be better than mixing it up with different sizes.
demetman on 04/17/2007 00:14:49
kit I plan on removing the 12W7 and enclosure all together and start fresh with a larger 15" sub that has a better sens rating and will optimally perform with my 1000/1 amp. this is more so an experiment to achieve more SPL by replacing the 12W7 in it's enclosure. It will go to the basement before I decide it's fate or resorection. I am simply looking for a 15" driver and optimum enclosure tuned for my vehicle.
Swez, I will look into getting an SPL reading fo the current set up. Would I need to go to an audio shop for a meater reading? I am aware that one can't achieve SQ and SPL so I'm willing to give up some SQL for SPL. Thanks,I'd like to get this project started asap while the funds are available.
Demetrios
30Hertz on 04/17/2007 03:39:31
As far as Fi goes, the Q series is more of the Sq series sub. If your going for SPL, look at the BTL and fully load that sucker!
Also take a look at the Stereo Integrity Magnum D2, They get loud, low and clean also!
demetman on 04/17/2007 09:59:00
Swez I'm having a hard time finding an audio shop that has an SPL meter. The only shop that has a meter is the shop that destroyed an install in a previous vehicle and ripped me off big time. Needless to say I won't be stopping by there. There has been a few privatelly owned shops close down as well as Tweeter Center in the past few months. Is there a way we could move foreward with this project without an SPL reading?
30Hertz, the BTL series Fi sub looks like one bad sub, however I only have a 1000/1 available for power. This sub wants at least 2000Wrms to get it started. I keep refering to the Powerbass 3X do to the 93dB sensativity rating. My 12w7 gets pretty loud but I need to really crank up the volume to get it going, hence the 86dB sens rating.
D
30Hertz on 04/17/2007 14:06:36
Yah I kinda overlooked the minor issue of power here haha. The BTL is a beast, and I'm getting one sometime in the future. One of the guys I know has a single 12 throwing up 151dB on the TermLab but he's pumping about 3000watts do it. (still not that much power for the dB drags). Most guys I know are running 8kw of power on two 15"s.
As far as the sensativity rating, yes the Powerbass 3x has a higher rating, but the 12w7 is a better build quality. Usually woofers with a high BI (motor strength) have a lower overall sensativity rating. I cant say much about the Powerbass since I havent personally ran it. Looks like a stout sub so either one would work.
As far as a SPL Meter, where are you from? Depending on your location I might be able to make some calls and see if I can set up a meter for you.
30
ShootuhMcBustaCap on 04/17/2007 21:20:52
Dem, don't feel too bad, I cant find anywhere do get my whip SPL tested either.
I had typed up two long replies, complete with tons of model reccommendations, but I lost both of them right before I finished. I wanted to ask before I did all of that again, are you totally with the single driver solution, or would consider a multi driver setup? This way you could run a pair of 15's 12's or even 10's to increase SPL, or keep SQL at an optimum setup. With a 1000/1 there really is endless possibilities of sub combinations
I really like the looks and specs of the Fi Q series. I could definitely hang with one of their beastly looking 18's fully optioned at $340.
cplkittle on 04/17/2007 21:25:40
I have installed a few powerbass 3x systems.. all 10's and 12's though. I was REALLY impressed with their performance, and they are still thumping 6-8 months later. They can take some abuse.
demetman on 04/17/2007 22:31:41
A 15" 3XL looks like it requires a 5cf ported enclosure for peak performance. When you guys look at the parameters, is this true? Do you guys think I will achieve a 3-5dB increase in SPL over the 12W7 using this driver? If I only knew that a 13W7 can move 39% more air than the 12W7 at time of purchase I wouldn't be in a situation to shell out $500 more bucks for a little more bass.
http://www.stereointegrity.com/Magnum12.html
This sub looks like a potential winner and fits the power requirements well. The only concern at an ameture glance is the lower X-max of 27mm compared to the 29mm of X-max of the W7.
Maybe the larger cone area would make up for the smaller degree of linear travel capacity of this sub.
30Hz I live in Mays Landing New Jersey just outside of Atlantic City. There really isn't many mobile audio shops in my area as car audio seems to be fading these days. One Stop Car Audio does have an SPL meter but they hacked my vehicle to hell and back on a previous install and I wouldn't even step foot in that place to use their bathroom.
Any ideas guys?
30Hertz on 04/17/2007 22:40:10
Do keep in mind that Xmax isnt a sole indicator of the subs ability to get loud. It helps yes, but your not going to notice a 2mm difference from 27 to 29mm =). Some of the subs you see at the dB drags are hitting huge numbers with a low XmaX sub. Why? Because their burping at higher Hz, doesnt require such a long throw since the sine wave is not as long.
IF you like the D2, Id say go with it! Their a solid sub with proven performance not only as a Daily Driver, but at comps also.
I know a guy that was hitting huge numbers with the SI mag D2 and personally, I would like to run one at some point or another but I've got my eye fixed on a BTL.
Let me see if I can find anyone around that area. Most of the guys I know live in SC, Indiana and some of the other states.
30
swez on 04/18/2007 16:13:22
The SI Mag D2 smacks of the RE designs we are all used to seeing today, but with a few minor mods. As Hertz mentioned, this sub has a few mm of extra excursion and a slight edge in SPL, (1w/1m) over the W7. Power handling is good as is BL and Fs. The box needs are not too unmanagble either.
I have been off on other projects of late and just have not had much time for searching things down like before. In this case, a true 92 - 95 dB of SPL @ 1w/1m from a very reputable sub maker would be an great option at the power level in that amp.
Also, knowing what kind of SPL is coming from your present system would be a good benchmark to know. A 2-3dB bump would be OK, but if we can figure out a way to land you a solid 5-6 dB more, that's gotta be something you would be happy with. The "Wicked One" enclosure is a great design for HT and very large vehicles, but the weight and size of this design would be an issue to consider carefully before diving in. (Using the W7 too)
Another option to consider is a well designed BP enclosure. However, these are best for SPL apps and do not give enough bass range to be considered a serious SQ/SQL sub design. Yes, they are indeed efficient, but of limited use to the SQL guy.
Am still thinking that a more efficient enclosure that does not greatly degrade SQL but gives medium-efficiency subs a few exta dB of SPL would be worth some research time. the question is where to look for such things and then figure out how to make it fit in your Magnum too.
Will ponder and look about as time permits and see what makes the most sense. If I find something of real interest, will come back to ya.
Swez
demetman on 04/18/2007 22:59:07
Sounds good Swez. Just to clarify, the Magnum D2 has less Xmax(27mm) than the 12W7(29mm). I won't purchase anything until we can determine a definate increase in SPL over the 12W7. Let me know if you find a potential product. If anyone has any places for me to search drivers for a high sens rating and power handeling to suit my needs let me know. I think 1-15" driver in a tuned enclosure is the way to go. Thanks
D
demetman on 04/23/2007 20:27:37
Ok I'm pretty convinced that the W7 is the indisputed king of SQ/SPL subs based on research, personal experience and the lack of any potential contenders from this broad base of very talented audio enthusiasts.
What do you guys think about upgrading to a 13W7 w/a custom tuned enclosure to reccomended specs? What kind of increase in SPL would likely be achieved from this larger more powerful driver. I already have a potential buyer for my 12W7 so this upgrade could very well fit the $500 budget. The JL specs show this driver capable of moving 39% more air, 4mm more Xmax than a 12W7 and 1000Wrms is optimum performance power for this sub. Do you guys think I would be happy with this set up? Thanks
D
cplkittle on 04/23/2007 21:09:53
I have never met a customer that was unhappy with a 13W7 and a 1000/1.
I think it is possible to at least double the output over a 12W7, especially if the enclosure is properly designed and constructed.
swez on 04/23/2007 21:17:21
Why would that be Kittle? Do you have any SPL numbers from both subs as a comparison?
Am sure the 13W7 is a premium sub in all respects. (It should be for the money) But why the extra bump? It's efficiency is about the same as the 12W7, but cone area is larger so it can move more air. The "no" of the 13W is also a tad more efficient too.
Any other thoughts?
Swez
cplkittle on 04/23/2007 21:31:40
Just an educated guess...
13W7
32mm xmax 107.35 sq in surface area 1000 watts
12W7
29mm xmax 84 sq in surface area 750 watts
Difference:
4mm Xmax
23.35 sq in more surface area
+250 watts
demetman on 04/24/2007 16:57:00
Wow, it's hard to believe a 13W7 could outperform a 12W7 to a substancial degree of output utelizing the same amount of power and same enclosure design! What does the above equasion(and I know it is a hypothesis) equate to in Db reference? When you say the right enclosure are you refering to a JL reccomended tuned enclosure of 2.375cf with a slot port tuned to 30Hz? Some manufacturers show a couple different ported enclosure specifications to yeild different result sin SPL/SQ. JL's port recommendations are derived through actual tests and measurements, not computer simulations and they only show one reccomended ported enclosure per sub. May be getting close to closure here. Thanks for the info.
D
cplkittle on 04/24/2007 21:11:22
5 posts ago you said you were building a custom enclosure to specs. The enclosure will have alot to do with the sound. Using the same enclosure may not yield the same results.
JL audio will work with you personally if you call them and ask what enclosure is best for your vehicle. I have called them several times in the past for recommended enclosure sizes for different vehicles.
I know +3dB seems like a stretch, but having worked with both the 12 and the 13w7, I do believe it is realistically achievable.
swez on 04/24/2007 22:08:56
The question I would put on JL tech's, How much of a difference in SPL would I likely see with a 12W7 vs a 13W7 in an optimal ported box and 1000 RMS to either sub?
If they say +3dB or more with the 13W7, it's worth a closer look.
Swez
demetman on 04/24/2007 22:35:27
Yes cplkittle I did say an enclosure would be built to exactly JL's specs, as I am aware of how crucial this is. A JL authorized dealer and a small shop owner in business over 15 yrs crafting quality custom boxes made my 12W7 enclosure and that is the only way I would go for a 13W7. I don't cut corners and don't trust my abilities to craft a tuned enclosure for such an expensive product.
The reason I am here probing for info is because JL will sugar coat all results of product output! I was originally planning to add another 12W7 to my set up because after consulting JL (Hector) I was told an increase in at least +3 to +6 dB would definatelly be achieved. I then came to this board asking for your opinions and was advised that no additional increase in SPL would be achieved splitting the 1000w to each driver.(Swez you remember this topic a bit back). Of course they want me to believe I will double my output they want my $700. They also advised me to dump the a/d/s/ comps I have and purchase the ZX comps for better MB perormance(another issue I had and resolved). Forgive me for being a PITA but I don't like to make rash decisions and always research investments to the fullest extent. These things aren't cheap!
D
cplkittle on 04/25/2007 00:04:11
I don't blame you at all for researching this, especially where close to $1,000 is involved.
All I can offer is an opinion. I have never metered the differences of a single 12w7 vs a single 13w7. I have heard both as singles, but for a true comparison, they would have to be metered in identical vehicles under strict conditions.
I am sure it is safe to assume the 1000/1 was tuned properly when this setup was installed. The settings will be different with the 13w7. (gain should increase as power handling is 250 watts more, and SS could possibly be dropped a few Hz).
I guess I should have been more vague and noted that a 3dB increase was an opinion, not a fact. I do firmly believe that you will notice a significant difference between the two subs.
swez on 04/25/2007 09:28:25
Right... some hard numbers are needed here to determine which direction to take.
See, I have worked with Dem at length on this project and have taken a position of ownership on the outcome. Meaning, "If I had this situation, knew all the key parameters and have already hit the SPL wall limits with current gear, what would I do with a given budget?" I would not shoot a wad of cash and "hope" it's better.
Also, the electrical system is pretty well maxed out now too. Adding another 1000 watts and a matching sub would help. But the overall cost of doing so is pretty high for such a minor increase. (~3dB more bass?)
This is why we are looking at a single HO sub that can deliver a solid +6dB more bass at 1000 watts. At this point, "guessing and hoping" are not a good option with the expense that is on the table already.
Dem, would it be possible to demo your 12W7 vs a 13W7 at the shop you have been doing buisness with? If they have a 13W7 and ported box on hand, that would give a better idea what to do next. Other than that, we are fishing in an unknown pool.
Swez
demetman on 04/25/2007 10:38:31
Ok guys I called JL this morning, explained what I was looking for and asked for their opinion. The tech I spoke to explained that adding a 2nd 12W7 in a ported enclosure is the most effective way to achieve a higher SPL using the same power. His quote was "There's no repacement for displacement" and calculated the difference in cone area from a single 12W7 to 2 12W7's and a 13W7.
A trip to the JL dealer is in line and maybe some questions can be answered there. I'll let you guys know what I find out.
D
cplkittle on 04/25/2007 12:13:52
There is no replacement for displacement, but if the displacement of one 12w7 is handicapped ( xmax cut in half due to splitting the power) is anything gained? If another amplifier is added along with another sub, I could see an increase, but dividing the power between the two subs? I don't see an increase there.
I'm just trying to play devil's advocate to hit this from all angles.
swez on 04/25/2007 15:57:10
Well, am wondering if there is a hidden bug in the system. Thinking about "Thermal Compression", (TC) as a possible culprit here???
TC is when the coils are fed lots of watts over an extended period of time and then the coils retain heat and the resistance goes up after a few minutes of heavy thumping and bass SPL drops as resistance goes up in the coils.
Tech Tip: We may be able to detect this in action too.
1. Measure the coil resistace with an ohmeter when cold and record the results
2. Then reconnect sub and let it work at high power for say 15-30 minutes
3. Quickly disconnect the sub wires and measure ohmic again
If the hot coil measurements are notably higher than when measure when cold, this is what is bringing down your sub SPL levels. When coil wires heat up, (the voice coils are very fine wires on a bobbin) they increase in resistance. If that coil set was like 2.5 ohms when cold and is now well over 5 ohms, that would explain a drop in power over time.
In some cases, we may hear a drop in power due to TC issues. An SPL meter can easily confirm it too. I cannot help but wonder if this would explain a loss in bass SPL after the sub warms up.
Basically, it goes like this:
1. On a cold sub, it sounds tight and robust
2. As the coils heat up, the coil resistance goes up
3. As the resistance goes up, SPL output drops in proportion to resistance changes
Anyone else got another possible explaination?
Swez
swez on 04/25/2007 16:12:50
Hey, a very good read for SPL/SQL sub users. Have a close look and mull it over.
This is a neat idea for more efficient cooling of the sub coils. Yes, it takes a machine shop to fabricate the cooling plug, but the idea has merit. Have a look:
http://www.audioroundtable.com/PiSpeakers/messages/17535.html
As long as the ported cooling holes are large enough and do not add any whistle effect noises, the idea makes very good sense huh?
Swez
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