need help choosign subs
Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=41809
Printed Date: May 02, 2024 at 6:05 PM
Topic: need help choosign subs
Posted By: lightnygga20
Subject: need help choosign subs
Date Posted: October 28, 2004 at 12:09 PM
i am looking at either purchasing 2 12 inch kicker l7s or 2 12 inch mtx thunder9500 for my 2 door chevy blazers are there any recommendations on which one to get or any other subs which i shoudl get i am also looking gfor ideas to replace the factory speakers i listen to mostly rap and someone told me it woudl be better for me to keep my factory head unit then to replace it is this true also thanks
Replies:
Posted By: jeffchilcott
Date Posted: October 28, 2004 at 5:04 PM
I would go with the 9500's just because they have a little edge on the SQ side for daily listening, I like L7's dont get me wrong but in a open cab for daily listening I dont know about how well that would sound
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2009 0-1000 Trunk WR 154.0DB 2009 1001+ Trunk WR
2007 USACI World Champion
2007 World Record
2006 USACI Finals 2nd Place
Posted By: Rushman
Date Posted: October 28, 2004 at 5:27 PM
As far as keeping the factory head unit , thats up to you but since your asking , I would personaly swap it out no question. Most , not all , factory H/U just dont have the same quality output as most aftermarket units. This also depends on what you want to spend $$$ on the unit as they can start at $50 wal-mart to $2,000 for a Nakamitchi. Remember usually with car stereo gear , you get what you pay for. Keep that in mind if you decide to change out the factory deck. I believe you can get a much better quality sound and maybe even more features and options (bells and whistles) with a new deck. Good Luck.......
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99 F-one fitty
Pioneer Premier H/U
Alpine EQ
Kicker 1200 amp
4 Kicker comp 10s
6 kicker SS65.2 components
Posted By: Poormanq45
Date Posted: October 28, 2004 at 6:04 PM
The efficiency/sensitivity on those subs is a little too low for my liking. I don't recommend getting any Speakers/Drivers/Woofers/Subs that have a efficiency/sensitivity lower than 92Db 1w/1m. I would recommend anything from Cerwin Vega. I recommend looking at these sites:
https://www.adelcom.net/CerwinVegaSSSubs.htm
https://www.adelcom.net/CerwinVegaVSSubs.htm
https://www.adelcom.net/CerwinVegaStealthBX.htm
https://www.cerwinvega.com/products/mobileaudio/index.html
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Posted By: 94legend
Date Posted: October 28, 2004 at 8:33 PM
I would suggest that you go with 12" Sony P5's !
^_^
Posted By: stevdart
Date Posted: October 28, 2004 at 10:12 PM
Poormanq45 wrote:
I don't recommend getting any Speakers/Drivers/Woofers/Subs that have a efficiency/sensitivity lower than 92Db 1w/1m.
That bit of advice......as it were......is that a joke or something? You've eliminated just about every quality subwoofer and most other drivers. Surely you typed it wrong. The Adire Brahma 12 has a true efficiency rating of 84.1 1W/1m. Are we to believe that it should be eliminated from our field of choices? ------------- Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
Posted By: Poormanq45
Date Posted: October 28, 2004 at 10:24 PM
No, I did not miss type that.
Lets put my 15in Cerwin Vega with a sensitivity of 98Db 1w/1m against your Adire Brahma with a 84.1Db 1w/1m and see which plays louder. For the fun of it, we would only feed them 32 watts. My cerwin Vega would be putting out approximately 113Db at 1m. The Adire Brahma would be putting out approximately 99.1Db at 1m. My Cerwin would be playing ~4 times as loud.
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Posted By: Rushman
Date Posted: October 28, 2004 at 10:25 PM
94legend.......How do they new Sony P5s sound compared to earlier models? I was never impressed with thier subs.
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99 F-one fitty
Pioneer Premier H/U
Alpine EQ
Kicker 1200 amp
4 Kicker comp 10s
6 kicker SS65.2 components
Posted By: Poormanq45
Date Posted: October 28, 2004 at 10:26 PM
So, I would be able to effectively power my sub by only using my Head Unit. Doesn't that sound good
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Posted By: stevdart
Date Posted: October 28, 2004 at 10:33 PM
So it's all about sensitivity then, is it? Great advice. I'll keep my eyes open for subs with 92 or better.  ------------- Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
Posted By: Poormanq45
Date Posted: October 28, 2004 at 10:36 PM
Further more, even if you feed the Brahma the maximum RMS power (1600w right?), it would still "only" play at 114.1 Db. That just plain sucks.
If I feed my Cerwin Vega the maximum RMS power (500w), it will play at 127Db.
Also, from what I've found out on the Brahma, it has a 29mm one way excursion, that means that it has a peak-to-peak excursion of 58mm? I don't like the idea of have the cone moving back and forth that far. By upgrading to a 15in, you could reduce the excursion ~25% and still get the same acoustical output.
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Posted By: Poormanq45
Date Posted: October 28, 2004 at 10:41 PM
It's not all about sensitivity. But the higher the sensitivity, the less power you have to put into the driver to get the same output level. And the less power you put into a driver, the less chance there is for distortion to occur. I like to drive my speakers at %25 of there RMS power rating. This allows that to play extremely clear. Now, I am not saying that when I put the full RMS power into them that they distort, it is a known fact that under-powering a driver will allow it to play more clearly.
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Posted By: Steven Kephart
Date Posted: October 28, 2004 at 10:56 PM
Poormanq45 wrote:
The efficiency/sensitivity on those subs is a little too low for my liking. I don't recommend getting any Speakers/Drivers/Woofers/Subs that have a efficiency/sensitivity lower than 92Db 1w/1m. I would recommend anything from Cerwin Vega. I recommend looking at these sites:
https://www.adelcom.net/CerwinVegaSSSubs.htm
https://www.adelcom.net/CerwinVegaVSSubs.htm
https://www.adelcom.net/CerwinVegaStealthBX.htm
https://www.cerwinvega.com/products/mobileaudio/index.html
You don't want to base your decision strictly on efficiency. For one thing, there are many different ways to measure efficiency. Some companies actually measure efficiency at 2.83 volts (4 ohm coils so not a 1 watt measurement) at half a meter and in vehicle. It makes their subs look really efficient, but it is kind of cheating. I'm not sure how CV rates their efficiency. Also, to gain a high efficiency, there had to be some compromising elsewhere. The sub either requires a much larger enclosure for a given alignment, or gives up low frequency extention. Sure our Brahma's aren't very efficient. But power is cheap, and we figured a smaller enclosure would be a better design goal. And as stevdart pointed out, a lot of other companies went this direction as well.  Steven Kephart Adire Audio -------------
Posted By: Steven Kephart
Date Posted: October 28, 2004 at 11:07 PM
Poormanq45 wrote:
Further more, even if you feed the Brahma the maximum RMS power (1600w right?), it would still "only" play at 114.1 Db. That just plain sucks.
How do you figure that? I will guarantee you that you can get a whole lot louder than 114 dB with 1600 watts to the Brahma. Heck, I've metered my Brahma 10 in a .36 cubic foot sealed enclosure at 143.7 dB. And that was with only about 1200 watts. Poormanq45 wrote:
Also, from what I've found out on the Brahma, it has a 29mm one way excursion, that means that it has a peak-to-peak excursion of 58mm? I don't like the idea of have the cone moving back and forth that far. By upgrading to a 15in, you could reduce the excursion ~25% and still get the same acoustical output.
Why not get a 15" Brahma then? Steven Kephart Adire Audio -------------
Posted By: Poormanq45
Date Posted: October 28, 2004 at 11:12 PM
Ya, I understand that companies use different ratings. I have a decible(can't remember real name) and power meter that I use when testing electrical equipment. I hooked up the power meter between the amp and the sub. And I placed the decibel meter ~3ft infront of the sub. (*Note: this was all done outside of the car.) The decibel always showed within 2Db of the rated efficiency at every power input level. So, I think the rating is pretty accurate. Cerwin Vega has been around for a while. There Sound quality is tried and true.
"Also, to gain a high efficiency, there had to be some compromising elsewhere. The sub either requires a much larger enclosure for a given alignment, or gives up low frequency extention. "
A higher efficiency can also be gained by: using a lighter weight cone, using a larger(greater magnetic flux) magnet, and/or using a tighter woven.larger voice coil.
Hear is an exerpt from a thesis I wrote a while back:
"One of the major disadvantages of the low efficiency that often is not readily detected by the novice is the limitation it places on any chance to use a bass-boost control on the amplifier (often desirable because of a poor listening room and/or recording)."
Consider a system that is 1-percent efficient. To produce 100-db spl at eight feet would require forty electrical watts from the amplifier (100-db spl at eight feet requires 0.4 acoustical watt from the speaker). Suppose still further that a 60-watt amplifier is being used-real continuous watts, not music power, peak, or other short-term values. In quality amplifiers, a 12-db bass-boost capability is usually considered conservative. A mere 6-db boost in bass response requires 160 electrical watts (40 watts times four), 100 watts more than the 60-watt amplifier can provide; 12-db boost would require 640 electrical watts. This means that the bass-boost controls are not really usable with the speaker selected.
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Posted By: Poormanq45
Date Posted: October 28, 2004 at 11:14 PM
"How do you figure that? I will guarantee you that you can get a whole lot louder than 114 dB with 1600 watts to the Brahma. Heck, I've metered my Brahma 10 in a .36 cubic foot sealed enclosure at 143.7 dB. And that was with only about 1200 watts."
I didn't actually go into an indepth calculation of the Db. I only used the standard 3Db increase requires a doubling of power.
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Posted By: Steven Kephart
Date Posted: October 28, 2004 at 11:15 PM
Poormanq45 wrote:
It's not all about sensitivity. But the higher the sensitivity, the less power you have to put into the driver to get the same output level. And the less power you put into a driver, the less chance there is for distortion to occur. I like to drive my speakers at %25 of there RMS power rating. This allows that to play extremely clear. Now, I am not saying that when I put the full RMS power into them that they distort, it is a known fact that under-powering a driver will allow it to play more clearly.
You are forgetting something though. Efficiency and power handling are dictated more by the enclosure used than the sub itself. You can get the Brahma to full excursion with only 600 watts in the right size enclosure. Also, the Brahma uses our XBL^2 motor which means it will naturally have less distortion. It isn't like a standard subwoofer where distortion increases as you turn it up. The Brahma stays clean up until it's moving 50 mm peak to peak. Take a listen to one and you will see what I mean. Steven Kephart Adire Audio -------------
Posted By: Poormanq45
Date Posted: October 28, 2004 at 11:20 PM
Steven Kephart: wow, I just realized that you work for Adire.
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Posted By: Poormanq45
Date Posted: October 28, 2004 at 11:26 PM
Posted By: Steven Kephart
Date Posted: October 28, 2004 at 11:27 PM
Poormanq45 wrote:
Cerwin Vega has been around for a while. There Sound quality is tried and true.
Yeah, but they mainly do pro sound where efficiency is important, and enclosure size isn't really an issue. There is a reason why most car audio companies don't have high efficiency as their main goal.
Poormanq45 wrote:
A higher efficiency can also be gained by: using a lighter weight cone,
Which also raises Fs, thereby decreasing your low frequency extention. Poormanq45 wrote:
using a larger(greater magnetic flux) magnet,
Sure, which decreases your Qts and increases your Fs, again decreasing your low frequency extention. Poormanq45 wrote:
and/or using a tighter woven.larger voice coil.
Actually that would add more weight which would decrease your efficiency. You just can't beat Hoffman's Iron Law. If you want high efficiency, you must sacrifice either extention or enclosure size. There is no way around it. Steven Kephart Adire Audio -------------
Posted By: Steven Kephart
Date Posted: October 28, 2004 at 11:31 PM
Poormanq45 wrote:
I didn't actually go into an indepth calculation of the Db. I only used the standard 3Db increase requires a doubling of power.
That's what I figured you used. But as you can see, it really doesn't work out well to real life. It doesn't take into acount BL compression, power compression, the transfer functions of the vehicle, the enclosure used, etc. We actually had a really good technical discussion on subwoofer a while ago. It included one of the best descriptions of how the physical parameters and theile/small parameters inter-relate and effect eachother, provided by my boss. Here's the link: https://caraudiotalk.com/forum//index.php?showtopic=2384 Steven Kephart Adire Audio -------------
Posted By: Steven Kephart
Date Posted: October 28, 2004 at 11:34 PM
Poormanq45 wrote:
Steven Kephart: wow, I just realized that you work for Adire.
"
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" If you want you can e-mail it to me at skephart@adireaudio.com. Steven Kephart Adire Audio -------------
Posted By: lightnygga20
Date Posted: October 29, 2004 at 9:35 AM
thanks and what about an amp to power them any recomendations money isnt a problem
Posted By: Ravendarat
Date Posted: October 29, 2004 at 11:51 AM
Back to the original question, I would also go with the 9500's just based on the fact that in open cab the solo's arent gonna be able to stick with the 9500's in sq. I would use a mtx1501d to power the subs, just make sure you have good cabling and a good charging system
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double-secret reverse-osmosis speaker-cone-induced high-level interference distortion, Its a killer
Posted By: boxmaker85
Date Posted: October 29, 2004 at 4:29 PM
Money isn't a problem...... *sigh* I only wish........
Posted By: Rushman
Date Posted: October 29, 2004 at 4:31 PM
I hear ya Boxmaker............must be nice huh?
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99 F-one fitty
Pioneer Premier H/U
Alpine EQ
Kicker 1200 amp
4 Kicker comp 10s
6 kicker SS65.2 components
Posted By: boxmaker85
Date Posted: October 29, 2004 at 8:28 PM
dude.... I'm scrapping for $50 to get another sub. Been saving for months now.... sucks.
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