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#1
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why do I always need bass boost?
I have had a few different setups over the years but one thing seems to
always stay consistent: I've always had to boost the bass on my head unit in order to get decent output from my subwoofers. Right now I have a Pioneer DEH-P2600 which has 2.2V preouts hooked up to a DEI D1200.1 amp and a pair of Infinity Reference subs. I need to have the 40 hz region EQ on my HU maxed out at +12 dB or otherwise I can't even tell I have subs. I've had other setups with completely different components and I have the same result. A lack of bass without any boost. I keep reading about other folks who get sufficient bass output while everything is flat so I don't understand why my systems require a big boost. Can someone suggest why this may be the case? I plan on getting a more expensive subwoofer in the near future and I don't want to be pushing it unnecessarily if I can help it. Thanks, George |
#2
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On Sat, 12 Mar 2005 23:23:44 -0500, George
wrote: I have had a few different setups over the years but one thing seems to always stay consistent: I've always had to boost the bass on my head unit in order to get decent output from my subwoofers. Right now I have a Pioneer DEH-P2600 which has 2.2V preouts hooked up to a DEI D1200.1 amp and a pair of Infinity Reference subs. I need to have the 40 hz region EQ on my HU maxed out at +12 dB or otherwise I can't even tell I have subs. I've had other setups with completely different components and I have the same result. A lack of bass without any boost. I keep reading about other folks who get sufficient bass output while everything is flat so I don't understand why my systems require a big boost. Can someone suggest why this may be the case? I plan on getting a more expensive subwoofer in the near future and I don't want to be pushing it unnecessarily if I can help it. Thanks, George Could be several things. First, I've always been happiest with a slight amount of boost in the bass frequencies rather than setting everything perfectly flat. Nothing near +12dB, though. What frequencies are you sending to your subs? You mentioned that you're boosting the 40 Hz region, but you didn't mention what your low-pass crossover is. If your crossover is set very low, like 50 Hz, and you're playing a lot of tapes, FM radio, MP3, or other sources that don't have very much low-frequency information in them, you just may not be sending much of anything to the subs in the first place. Also, are you sure you have the amplifier gains set correctly on your sub amp? How did you set them? What size/impedance are your subs? Are you using the low-pass crossover on the head unit, on the amplifier, or both? Could your subs be wired out-of-phase and cancelling each other out? What kind of enclosure are your subs in? It sounds like something's misconfigured, because depending on the impedance of your subs, your amplifier should be capable of providing somewhere between 450 and 1200 watts. Even just 450 watts into a pair of subs should be more than enough to make your hair bounce. -- Scott Gardner "If you find yourself in a hole, the first thing to do is stop diggin'." |
#3
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What kind of car? Where are the subs located? What's the box like? Where
is it positioned? "George" wrote in message news I have had a few different setups over the years but one thing seems to always stay consistent: I've always had to boost the bass on my head unit in order to get decent output from my subwoofers. Right now I have a Pioneer DEH-P2600 which has 2.2V preouts hooked up to a DEI D1200.1 amp and a pair of Infinity Reference subs. I need to have the 40 hz region EQ on my HU maxed out at +12 dB or otherwise I can't even tell I have subs. I've had other setups with completely different components and I have the same result. A lack of bass without any boost. I keep reading about other folks who get sufficient bass output while everything is flat so I don't understand why my systems require a big boost. Can someone suggest why this may be the case? I plan on getting a more expensive subwoofer in the near future and I don't want to be pushing it unnecessarily if I can help it. Thanks, George |
#4
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Mark and Scott,
My setup is as follows: Car: 1999 Nissan Altima Subs: Two 12" Infinity Reference 300W 4 ohm single voice coil subs. They are in sealed 1.25 cubic foot boxes which is their recommended volume. I have tried a ported box before and it didn't seem to help much. The subs are in the traditional spot, firing backwards right behind my rear seats in my trunk. The subs are wired directly to each of the two outputs of the amp. It's my understanding that the amp is internally bridged, so hooking a pair of 4 ohm SVC subs to the two terminals would result in a 2 ohm load. Amp: The amp is rated at 1200W @ 1 ohm and 600W @ 2 ohms. I have the low pass filter set at around 90 Hz (with no crossover functions on my head unit). I have the subsonic filter turned off and the bass boost on the amp turned to zero. I have set the gain with a digital multimeter so that when I have my volume turned to 37 out of 62 (which is about the highest I would turn it), a 50 Hz sine wave produces 34.6V or 600W @ 2 ohms. The amp does have a remote gain level knob that I initially set to maximum when setting the gain on my amp. However the last time I set it halfway when setting the gain on my amp because I always had it at maximum before and it seemed to be doing me no good as I would never turn it down. I have a friend with a lesser setup than mine (smaller subs, less powerful amp, similar sedan, sealed box) and his bass is very strong even with very little bass boost. If there are any suggestions you guys can make, I would be willing to try them out. Do you think maybe I set my gain wrong somehow? Thanks very much. George On Sun, 13 Mar 2005 00:20:22 -0500, Scott Gardner wrote: Could be several things. First, I've always been happiest with a slight amount of boost in the bass frequencies rather than setting everything perfectly flat. Nothing near +12dB, though. What frequencies are you sending to your subs? You mentioned that you're boosting the 40 Hz region, but you didn't mention what your low-pass crossover is. If your crossover is set very low, like 50 Hz, and you're playing a lot of tapes, FM radio, MP3, or other sources that don't have very much low-frequency information in them, you just may not be sending much of anything to the subs in the first place. Also, are you sure you have the amplifier gains set correctly on your sub amp? How did you set them? What size/impedance are your subs? Are you using the low-pass crossover on the head unit, on the amplifier, or both? Could your subs be wired out-of-phase and cancelling each other out? What kind of enclosure are your subs in? It sounds like something's misconfigured, because depending on the impedance of your subs, your amplifier should be capable of providing somewhere between 450 and 1200 watts. Even just 450 watts into a pair of subs should be more than enough to make your hair bounce. |
#5
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Yeah, you may want to try repositioning the box around in the trunk to see
if that helps. But I suspect it's just a matter of gains. This is not uncommon. The gains for the other amnps are just too high compared to the gains for the sub amp. Mark and Scott, My setup is as follows: Car: 1999 Nissan Altima Subs: Two 12" Infinity Reference 300W 4 ohm single voice coil subs. They are in sealed 1.25 cubic foot boxes which is their recommended volume. I have tried a ported box before and it didn't seem to help much. The subs are in the traditional spot, firing backwards right behind my rear seats in my trunk. The subs are wired directly to each of the two outputs of the amp. It's my understanding that the amp is internally bridged, so hooking a pair of 4 ohm SVC subs to the two terminals would result in a 2 ohm load. Amp: The amp is rated at 1200W @ 1 ohm and 600W @ 2 ohms. I have the low pass filter set at around 90 Hz (with no crossover functions on my head unit). I have the subsonic filter turned off and the bass boost on the amp turned to zero. I have set the gain with a digital multimeter so that when I have my volume turned to 37 out of 62 (which is about the highest I would turn it), a 50 Hz sine wave produces 34.6V or 600W @ 2 ohms. The amp does have a remote gain level knob that I initially set to maximum when setting the gain on my amp. However the last time I set it halfway when setting the gain on my amp because I always had it at maximum before and it seemed to be doing me no good as I would never turn it down. I have a friend with a lesser setup than mine (smaller subs, less powerful amp, similar sedan, sealed box) and his bass is very strong even with very little bass boost. If there are any suggestions you guys can make, I would be willing to try them out. Do you think maybe I set my gain wrong somehow? Thanks very much. George On Sun, 13 Mar 2005 00:20:22 -0500, Scott Gardner wrote: Could be several things. First, I've always been happiest with a slight amount of boost in the bass frequencies rather than setting everything perfectly flat. Nothing near +12dB, though. What frequencies are you sending to your subs? You mentioned that you're boosting the 40 Hz region, but you didn't mention what your low-pass crossover is. If your crossover is set very low, like 50 Hz, and you're playing a lot of tapes, FM radio, MP3, or other sources that don't have very much low-frequency information in them, you just may not be sending much of anything to the subs in the first place. Also, are you sure you have the amplifier gains set correctly on your sub amp? How did you set them? What size/impedance are your subs? Are you using the low-pass crossover on the head unit, on the amplifier, or both? Could your subs be wired out-of-phase and cancelling each other out? What kind of enclosure are your subs in? It sounds like something's misconfigured, because depending on the impedance of your subs, your amplifier should be capable of providing somewhere between 450 and 1200 watts. Even just 450 watts into a pair of subs should be more than enough to make your hair bounce. |
#6
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The gain could be too low even if I used a voltmeter to set it to the
subs' recommended RMS ratings? George On Sun, 13 Mar 2005 14:12:27 -0500, MZ wrote: Yeah, you may want to try repositioning the box around in the trunk to see if that helps. But I suspect it's just a matter of gains. This is not uncommon. The gains for the other amnps are just too high compared to the gains for the sub amp. |
#7
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On Sun, 13 Mar 2005 16:18:24 -0500, George
wrote: The gain could be too low even if I used a voltmeter to set it to the subs' recommended RMS ratings? George On Sun, 13 Mar 2005 14:12:27 -0500, MZ wrote: Yeah, you may want to try repositioning the box around in the trunk to see if that helps. But I suspect it's just a matter of gains. This is not uncommon. The gains for the other amnps are just too high compared to the gains for the sub amp. Well, when you used the voltmeter and measured 600W at the amp's outputs, did it SOUND like six hundred watts going into a pair of twelves? If not, you may have been using the meter incorrectly, or there could be a phasing problem with your subs. Are you sure the impedance of your subs at 50 Hz is 2 oms? If it's not, that could throw your meter readings off significantly. Scott Gardner -- Scott Gardner "I've been accused of vulgarity. I say that's bull****." (Mel Brooks) |
#8
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The gain could be too low even if I used a voltmeter to set it to the
subs' recommended RMS ratings? Voltmeter to set the gains? Why? Setting gains is simple. You crank it all the way up for the sub amp (at least in your case), and then adjust the other gains relative to that one. Use your ears, not meters. |
#9
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OK, I think I solved the problem. It seems the remote gain knob was
somehow attenuating the output. I simply unplugged the knob's cord from the amp and reset the gain. Now everything seems much better and I don't need 12 decibels of boost. Thanks for your help, guys. Much appreciated. George On Sun, 13 Mar 2005 16:21:58 -0500, Scott Gardner wrote: Well, when you used the voltmeter and measured 600W at the amp's outputs, did it SOUND like six hundred watts going into a pair of twelves? If not, you may have been using the meter incorrectly, or there could be a phasing problem with your subs. Are you sure the impedance of your subs at 50 Hz is 2 oms? If it's not, that could throw your meter readings off significantly. Scott Gardner |
#10
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in the traditional spot, firing backwards right behind my rear seats
in my trunk Traditional?!?!? You mean crappy? You'll get a 3-6 db increase by moving your sub box all the way toward the back of the trunk firing directly at the back of the car. Dynamatting the back wall of the trunk (lower part of trunk lid) helps a lot as well. This position has been proven to prevent all the bass wave cancelling that can occur in your "traditional spot". On Sun, 13 Mar 2005 00:24:03 -0500, "MZ" wrote: What kind of car? Where are the subs located? What's the box like? Where is it positioned? "George" wrote in message news I have had a few different setups over the years but one thing seems to always stay consistent: I've always had to boost the bass on my head unit in order to get decent output from my subwoofers. Right now I have a Pioneer DEH-P2600 which has 2.2V preouts hooked up to a DEI D1200.1 amp and a pair of Infinity Reference subs. I need to have the 40 hz region EQ on my HU maxed out at +12 dB or otherwise I can't even tell I have subs. I've had other setups with completely different components and I have the same result. A lack of bass without any boost. I keep reading about other folks who get sufficient bass output while everything is flat so I don't understand why my systems require a big boost. Can someone suggest why this may be the case? I plan on getting a more expensive subwoofer in the near future and I don't want to be pushing it unnecessarily if I can help it. Thanks, George |
#11
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On Mon, 21 Mar 2005 03:45:48 GMT, Rod wrote:
in the traditional spot, firing backwards right behind my rear seats in my trunk Traditional?!?!? You mean crappy? You'll get a 3-6 db increase by moving your sub box all the way toward the back of the trunk firing directly at the back of the car. Dynamatting the back wall of the trunk (lower part of trunk lid) helps a lot as well. This position has been proven to prevent all the bass wave cancelling that can occur in your "traditional spot". Well, everything in life involves some kind of compromise, and sub placement is no different. In most of the sedans and coupes I've owned, putting a large box where you describe (in the trunk, slid all the way away from the back seats, firing toward the rear of the car) makes the rest of the trunk a pain in the ass to use. With your location, the box is situated right at the trunk opening. Anything you want to put in the trunk has to go in between the box and the edge of the trunk opening, then positioned between the sub box and the rear seat, or off to the sides of the sub box, if your trunk is wide enough. While the conventional location up against the back seat and firing rearward may not give the most SPL, watts are cheap, and if it bothers me that much, I'll buy a bigger amp. -- Scott Gardner "Sense is not cognition but sensation." (Douglas Robinson) |
#12
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Check your newsreader, Rod. I didn't write what you attributed to me.
"Rod" wrote in message news in the traditional spot, firing backwards right behind my rear seats in my trunk Traditional?!?!? You mean crappy? You'll get a 3-6 db increase by moving your sub box all the way toward the back of the trunk firing directly at the back of the car. Dynamatting the back wall of the trunk (lower part of trunk lid) helps a lot as well. This position has been proven to prevent all the bass wave cancelling that can occur in your "traditional spot". On Sun, 13 Mar 2005 00:24:03 -0500, "MZ" wrote: What kind of car? Where are the subs located? What's the box like? Where is it positioned? "George" wrote in message news I have had a few different setups over the years but one thing seems to always stay consistent: I've always had to boost the bass on my head unit in order to get decent output from my subwoofers. Right now I have a Pioneer DEH-P2600 which has 2.2V preouts hooked up to a DEI D1200.1 amp and a pair of Infinity Reference subs. I need to have the 40 hz region EQ on my HU maxed out at +12 dB or otherwise I can't even tell I have subs. I've had other setups with completely different components and I have the same result. A lack of bass without any boost. I keep reading about other folks who get sufficient bass output while everything is flat so I don't understand why my systems require a big boost. Can someone suggest why this may be the case? I plan on getting a more expensive subwoofer in the near future and I don't want to be pushing it unnecessarily if I can help it. Thanks, George |
#13
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"Rod" wrote in message news in the traditional spot, firing backwards right behind my rear seats in my trunk Traditional?!?!? You mean crappy? You'll get a 3-6 db increase by moving your sub box all the way toward the back of the trunk firing directly at the back of the car. Dynamatting the back wall of the trunk (lower part of trunk lid) helps a lot as well. This position has been proven to prevent all the bass wave cancelling that can occur in your "traditional spot". My subs are in the same "traditional spot" and they sound just fine to me. On Sun, 13 Mar 2005 00:24:03 -0500, "MZ" wrote: What kind of car? Where are the subs located? What's the box like? Where is it positioned? "George" wrote in message news I have had a few different setups over the years but one thing seems to always stay consistent: I've always had to boost the bass on my head unit in order to get decent output from my subwoofers. Right now I have a Pioneer DEH-P2600 which has 2.2V preouts hooked up to a DEI D1200.1 amp and a pair of Infinity Reference subs. I need to have the 40 hz region EQ on my HU maxed out at +12 dB or otherwise I can't even tell I have subs. I've had other setups with completely different components and I have the same result. A lack of bass without any boost. I keep reading about other folks who get sufficient bass output while everything is flat so I don't understand why my systems require a big boost. Can someone suggest why this may be the case? I plan on getting a more expensive subwoofer in the near future and I don't want to be pushing it unnecessarily if I can help it. Thanks, George |
#14
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Actually - I think he may have. What he is trying to say is that you
can get your subs to perform better by moving the box. The building of the box can also make a huge difference. Make sure it is sealed 100%. If it is a ported box, it still needs to be sealed everywhere except for the port. It really seems like those subs should be pretty loud. And like Rod said - don't fire them into the back of the seats, as fabric and foam absorb noise. Face them backwards, and move the box closer to the back of the trunk. Sounds weird, but give it a try. You also may have to try different spots to get them in a place where you can use your trunk if need be. Mark MZ wrote: Check your newsreader, Rod. I didn't write what you attributed to me. "Rod" wrote in message news in the traditional spot, firing backwards right behind my rear seats in my trunk Traditional?!?!? You mean crappy? You'll get a 3-6 db increase by moving your sub box all the way toward the back of the trunk firing directly at the back of the car. Dynamatting the back wall of the trunk (lower part of trunk lid) helps a lot as well. This position has been proven to prevent all the bass wave cancelling that can occur in your "traditional spot". On Sun, 13 Mar 2005 00:24:03 -0500, "MZ" wrote: What kind of car? Where are the subs located? What's the box like? Where is it positioned? "George" wrote in message news I have had a few different setups over the years but one thing seems to always stay consistent: I've always had to boost the bass on my head unit in order to get decent output from my subwoofers. Right now I have a Pioneer DEH-P2600 which has 2.2V preouts hooked up to a DEI D1200.1 amp and a pair of Infinity Reference subs. I need to have the 40 hz region EQ on my HU maxed out at +12 dB or otherwise I can't even tell I have subs. I've had other setups with completely different components and I have the same result. A lack of bass without any boost. I keep reading about other folks who get sufficient bass output while everything is flat so I don't understand why my systems require a big boost. Can someone suggest why this may be the case? I plan on getting a more expensive subwoofer in the near future and I don't want to be pushing it unnecessarily if I can help it. Thanks, George |
#15
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Actually - I think he may have. What he is trying to say is that you
can get your subs to perform better by moving the box. The building of the box can also make a huge difference. Make sure it is sealed 100%. If it is a ported box, it still needs to be sealed everywhere except for the port. It really seems like those subs should be pretty loud. And like Rod said - don't fire them into the back of the seats, as fabric and foam absorb noise. Face them backwards, and move the box closer to the back of the trunk. Sounds weird, but give it a try. You also may have to try different spots to get them in a place where you can use your trunk if need be. Mark Actually, it has nothing to do with the fabric and foam of the seats. It has to do with cancellation. Turning your box around automatically moves it towards the rear of the trunk. But, as others have said, it's sometimes impractical to place the box all the way to the rear, because then you lose trunk space. However, behind the wheel wells is often a good spot. Anyway, Rod needs to look at his newsreader or news server because he was quoting someone else when he replied to me. Just a heads up to him. |
#16
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Thanks, MZ. I apologize... I simply replied to the wrong post.
On Mon, 21 Mar 2005 11:22:05 -0500, "MZ" wrote: Actually - I think he may have. What he is trying to say is that you can get your subs to perform better by moving the box. The building of the box can also make a huge difference. Make sure it is sealed 100%. If it is a ported box, it still needs to be sealed everywhere except for the port. It really seems like those subs should be pretty loud. And like Rod said - don't fire them into the back of the seats, as fabric and foam absorb noise. Face them backwards, and move the box closer to the back of the trunk. Sounds weird, but give it a try. You also may have to try different spots to get them in a place where you can use your trunk if need be. Mark Actually, it has nothing to do with the fabric and foam of the seats. It has to do with cancellation. Turning your box around automatically moves it towards the rear of the trunk. But, as others have said, it's sometimes impractical to place the box all the way to the rear, because then you lose trunk space. However, behind the wheel wells is often a good spot. Anyway, Rod needs to look at his newsreader or news server because he was quoting someone else when he replied to me. Just a heads up to him. |
#17
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Good point... I'm struggling with the great sound vs. practicality
issue myself right now. We are considering designing a track-based system whereby my box can be moved back and locked against the back of the seat for when I need the trunk, but rolled and locked against the back of the trunk for when I want the best sound. Getting the track to "fold" up in order to access my spare tire is proving to be the tricky part. If all else fails, we may redesign my rear deck to fit a 12" sub in free air configuration between my 6.5" full rangers. Unfortunately, I want a more stock look to my system so as not to attract thieves. Mounting a 12" speaker in the deck would not help my cause On Sun, 20 Mar 2005 23:01:56 -0500, Scott Gardner wrote: On Mon, 21 Mar 2005 03:45:48 GMT, Rod wrote: in the traditional spot, firing backwards right behind my rear seats in my trunk Traditional?!?!? You mean crappy? You'll get a 3-6 db increase by moving your sub box all the way toward the back of the trunk firing directly at the back of the car. Dynamatting the back wall of the trunk (lower part of trunk lid) helps a lot as well. This position has been proven to prevent all the bass wave cancelling that can occur in your "traditional spot". Well, everything in life involves some kind of compromise, and sub placement is no different. In most of the sedans and coupes I've owned, putting a large box where you describe (in the trunk, slid all the way away from the back seats, firing toward the rear of the car) makes the rest of the trunk a pain in the ass to use. With your location, the box is situated right at the trunk opening. Anything you want to put in the trunk has to go in between the box and the edge of the trunk opening, then positioned between the sub box and the rear seat, or off to the sides of the sub box, if your trunk is wide enough. While the conventional location up against the back seat and firing rearward may not give the most SPL, watts are cheap, and if it bothers me that much, I'll buy a bigger amp. |
#18
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Scott, buying more watts will only ensure that your low bass cancels
itself more effectively, and that you cancel your mid-bass in the cabin that much more. Hard-hitting bass is what makes or breaks a system. When speakers are out of phase with each other, it makes the whole system sound flat and lifeless. On Sun, 20 Mar 2005 23:01:56 -0500, Scott Gardner wrote: On Mon, 21 Mar 2005 03:45:48 GMT, Rod wrote: in the traditional spot, firing backwards right behind my rear seats in my trunk Traditional?!?!? You mean crappy? You'll get a 3-6 db increase by moving your sub box all the way toward the back of the trunk firing directly at the back of the car. Dynamatting the back wall of the trunk (lower part of trunk lid) helps a lot as well. This position has been proven to prevent all the bass wave cancelling that can occur in your "traditional spot". Well, everything in life involves some kind of compromise, and sub placement is no different. In most of the sedans and coupes I've owned, putting a large box where you describe (in the trunk, slid all the way away from the back seats, firing toward the rear of the car) makes the rest of the trunk a pain in the ass to use. With your location, the box is situated right at the trunk opening. Anything you want to put in the trunk has to go in between the box and the edge of the trunk opening, then positioned between the sub box and the rear seat, or off to the sides of the sub box, if your trunk is wide enough. While the conventional location up against the back seat and firing rearward may not give the most SPL, watts are cheap, and if it bothers me that much, I'll buy a bigger amp. |
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