Alright guys....i got lucky.....i got a new 10inch DVC 4 ohm Type S sub for a hundred bucks...they are last years model so they were selling them cheap......So there i was, installing it into the box and my screw driver slipped...in my head, im thinking..nooooooooooo, as the screw driver creates an ever so small divet into the rubber around the sub.....now, this divet is extremely small and did not pierce through the rubber or anything to make a hole. So im thinking it should be fine...any suggestions though...would be appreciated. ...After it was installed, i drove around testing it at high volumes...and the amp shut off on me....because my amp is running this at 2ohms i realised i had forgot to readjust the gain...so i did that at it seems fine so far. But i have a question. I know that gain is essentially input sensitivity...right? so does that mean that a higher gain, means that the amp is working less because of a more clear signal or something? also, when i set the gain, i read a bunch of instrucitions which said to set all settings to zero or off etc. But what about the subwoofer control on the HU..if i set that to zero, then there is no signal being sent to the amp. So what i did, was set the subwoofer volume on the HU to 1...and set the gain using a DMM. but i have found that this is too loud at times and i cant go lower....so i just lowered the gain a bit to give my self some more lee-way....im thinking this should be fine, and ive turned off the bass boost so im hoping that amp doesnt go into shutdown mode again....i will test it later today.....Also, i am having increased dimming issues becuase of the 2ohm load....i have decided to buy a red or yellow top this friday...I have heard that this will solve the problem...i upgraded my 2 ground wires in the 'big three' but did not do the positive wire because the alternator is extremely tough to reach....So my plan is to buy a red or yellow top on friday and see. What you guys think about all this...sorry for such a long post...
Replies (14)
gsandha99 on 10/15/2007 11:16:01
oh and one more thing. my amp has a 'bass expander function'...what the f' is that?
swez on 10/15/2007 17:59:32
The length of the post is OK, but the format is hard to read. Allow me to edit and answer your concerns:
Alright guys....i got lucky.....i got a new 10inch DVC 4 ohm Type S sub for a hundred bucks...they are last years model so they were selling them cheap......
So there i was, installing it into the box and my screw driver slipped...in my head, im thinking..nooooooooooo, as the screw driver creates an ever so small divet into the rubber around the sub.....now, this divet is extremely small and did not pierce through the rubber or anything to make a hole. So im thinking it should be fine...any suggestions though...would be appreciated.
[A thin dab of silicone sealer will often do the trick and flexes with the rubber too. Other glues are rigid when they cure and that would make a crusty spot too. Let the silicone cure for a few hours or use a hair drier on low heat, high air to speed up the curing process. If possible, try to do the repair on the under side of the surround. That way, the repair is invisible.]
...After it was installed, i drove around testing it at high volumes...and the amp shut off on me....because my amp is running this at 2ohms i realised i had forgot to readjust the gain...so i did that at it seems fine so far. But i have a question. I know that gain is essentially input sensitivity...right? so does that mean that a higher gain, means that the amp is working less because of a more clear signal or something?
[The amp gains are input sensitivity compensators. We use this feature to match the HU output voltage to the amp's input side. The best way to do this is with an AC volt meter and a reference level test tone of say 50 Hz., for subs. The sub is getting full power at 24.5 volts AC.]
Also, when i set the gain, i read a bunch of instrucitions which said to set all settings to zero or off etc. But what about the subwoofer control on the HU..if i set that to zero, then there is no signal being sent to the amp. So what i did, was set the subwoofer volume on the HU to 1...and set the gain using a DMM. but i have found that this is too loud at times and i cant go lower....so i just lowered the gain a bit to give my self some more lee-way....im thinking this should be fine, and ive turned off the bass boost so im hoping that amp doesnt go into shutdown mode again....i will test it later today.....
[Here's a video and written instructions on how to set amp gains. They used a resisitive load, but a sub will also work as a test load.]
http://www.clubknowledge.com/cgi-bin/car_audio_faq/faq.cgi?g4813
Also, i am having increased dimming issues becuase of the 2ohm load....i have decided to buy a red or yellow top this friday...I have heard that this will solve the problem...i upgraded my 2 ground wires in the 'big three' but did not do the positive wire because the alternator is extremely tough to reach....So my plan is to buy a red or yellow top on friday and see. What you guys think about all this...sorry for such a long post...
[Yes, light dimming will become an issue as the amp is now pulling 2x the power it did at 4 ohms. A higher CCA rated BAT will help. But, that power line between the ALT and + terminal of the BAT is also important to upgrade. Yes, it may be a pain to get to, but adding another wire to the stock one will lower resistance and allow more power to flow to the BAT. That's the most important line of a Big 3 upgrade.
In this small car, it might only have a #6-8 gage wire as stock. Adding another #4-8 gage line to this will maximize power flow from the ALT to BAT and reduce/eliminate dimming]
Swez
PS Avoid using bass boost and related circuits when possible. If used, a moderate boost of +3 to +6 dB boost is more than enough. Some Rap, Country & Hip-Hop songs have lots of bass juiced into the mix already. Rock, Classical and some Jazz music can use a little help as the bass is not so prominent This is where a little bass EQ can really help bring up the bass.
gsandha99 on 10/16/2007 11:28:17
Thanks a tonne swez...i really appreciate your long and thought out answers.
About the divet in the sub....It is reaaaalllly smaalll.....and i think i should leave it like that for fear of adding something not required at the moment.....i really dont think it will make a difference, or get bigger or anything...what do you think?
WHen you say, "The sub is getting full power at 24.5 volts AC." Are you saying that should be the maximum the sub is getting at any given volume/level? Because...if i set my gains to that...and i turn my volume up, the voltage increases...no? (i havent checked out the video yet, as i am at work, so if that answers the question..sorry).
With regards to dimming....I will be getting the red/yellow top for about 200 bucks this friday. I will try to save up some more from my budget and get the positive wire changed aswell....that will prolly be another 100 dollars, he was saying....but i know it will be well worth it...
And your right, i turned off the bass boost and bass expander...and it sounds much better...these settings were probably over exerting the amp anyways.
swez on 10/17/2007 05:44:16
That video explains amp gain adjustments it very well. (How to set gains properly) Just make note of the steps they use and then adjust the amp gain so that your sub is getting a solid 24-25 volts with a 50 Hz test tone. Doing this correctly will give the sub plenty of "clean" bass power on music that has strong bass tracks.
Defeating the bass expander circuit, prevents over-driving the amp. (This is commonly called "CLIPPING") We want to avoid clipping as it's hard on the sub and amp. (High distortion numbers means clipping) Most Bass Expander circuits can deliver up to +18dB of bass boost @ 45 Hz. This often means severe clipping and high distortion levels to the sub. (Don't use that feature unless you can manage the boost w/o clipping the amp signals to the sub)
Swez
gsandha99 on 10/17/2007 11:54:45
I find that when i properly adjust the gain on the amp to the proper voltoage, that my gain is very high...almost maximum...this also gives the bass sound less of a fullness and crispness in sound...its hard to describe, but it sounds more fluttery
But what i think i will do. Is lower the LPF to 55hz from where i had it at 85hz and see if that fixes the problem...suggestions?
swez on 10/17/2007 19:53:18
Hummm, your amp may be clipping and this will cause the bass to sound raspy and not clean and full. (Fuzzy or sloppy lows are common when the amp begins to clip)
Part of this is the sub size and perhaps the enclosure is not well suited to this sub either. This sub works best in a 0.85 ft^3 sealed box. It can handle a wider range, (0.65 - 1.5 ft^3) but as we go larger than 0.85, the lows are deeper, but not as much cone control and power handling.
What are the dimensions of your enclosure anyway?
Swez
jamesp on 10/18/2007 08:22:05
gsandha99,
Did you have the volume turned up to the point just below where distortion begins when you were measuring the AC voltage?
The video clip shows how to set the gains using a dummy load to represent the load the amp will "see" from the sub. A few amps allow you to set the gains without a load on the end of the speaker wires.
In you case you will probably have to have your sub connected, Play the test tone with no boost or cut as described eariler. Turn the volume up to the maximum level you can achieve with no distortion with your gain set low. Now rotate the gain knob while vwatching the volt meter....CAUTION.....you need some ear protection here...when I used a 60Hz tone at high volume setting my voltage to achieve 500 watts with a 2 Ohm load, it was vibrating my eyeballs...In my case my target AC voltage was around 31.6V ac which required about 3/4 of the travel of the gain knob. when I was close to the desired voltage needed I found that a very small increase in the gain control had much more affect on voltage than the same amount of travel had at lower gain settings.
I think my question to you is; did you set your gains with the head unit volume turned up about 75% or so or did you set it with the volume turned way down?
gsandha99 on 10/18/2007 15:28:33
Hey guys,
Swez...you know, im not sure how big my box is...its a wedge design. Sealed...seems like the standard size...not small..not big....how would i measure it?
James....you know..i didnt have the sub hooked up....so im guessing this is where the problem might lie.....i think your right about the load.....although would it make sense to turn down the gain and up the bass boost to achieve a better sound...or is this not a good idea...im asking if it is good to basically set it by ear....
swez on 10/18/2007 17:33:43
Use the link below to get a pretty close number on the internal volume of the enclosure you have. Just pick the shape of box, fill in the external dimensions & wood thickness as measured and the calculator will do the rest. (Wedge enclosure 1 or 2)
http://www.the12volt.com/caraudio/boxcalcs.asp
Once we know the internal airspace, subtract the sub displacement.
Displacement = 0.050 cu. ft. (0.05 ft^3 here) Then we know the actual internal airspace the sub is working within. Hopefully, the net airspace is under 1.0 ft^3, but larger than 0.70 ft^3.
Proper gain setting is a bit of an art form. We are balancing several parameters here to get it right. When using Bass Boost on some tunes, it's OK to go +3dB or a tad more on Rock and such. On Rap and other similar music, that may be too much as the amp will clip and the sub now sound like "hammered poop". 8~(
Swez
jamesp on 10/19/2007 07:29:40
Swez,
If he is setting the gain to the proper AC voltage with no load on the amp it wont even be close will it. I know that some JL amps will allow you to do this and probably others, but will his amp allow it. I dont know what amp he is using.
It seems that he adjusted his bass boost on the head unit to a setting of 1 and then had to turn the gain knob up almost all the way to get to the required AC voltage. If his amp requires a load to set the gain and he says he didnt have the sub hooked up so the gain setting is probably way to high, right,.......unless of course his amp doesnt require any load to set the input sensitivity.
added at 9:53am: I see that he is using a Kenwood KAC 8101 amp....can the gain be properly set with no load on the the amp output. If not, I suspect that the settings arrived at with no load are resulting in the dreaded square waveform syndrome as the AC voltage at the near maximum gain setting is probably much higher than what it needs to be. Whadduya think ?
gsandha99 on 10/19/2007 11:11:57
Also, the gain that is eventually set....is that amount of voltage a maximum that the amp should get? or is that the minimum...because if i turn up the sub control on HU or volume or w/e, it will obvy be pumping more voltage into the amp than what i originall set it too.
jamesp on 10/19/2007 14:48:52
Gsandha, when you properly adjust the gain, the AC voltage that you set is the voltage the amp sends to the sub to correspond to the RMS wattage of the load(sub) the amp sees.
That is why when you set the gain you first turn the volume up on the head unit to the loudest position that you will ever listen at or the loudest it will go without distorting(clipping)
Now you put your test tone disc into the player and let it play at the high volume that you previously set it at. Now measure the AC voltage at the sub channel speaker outputs with your meter.Start off with the gain at about the mid point and once you read the voltage, adjust the gain knob untill tou reach the target voltage.
For example: my Alpine type R sub is rated at 500 watts RMS and wired in parrallel for a 2 Ohm load. By doing the math or looking at a chart I determine that I need to see 31.6 volts ac at the speaker output in order to be sure that my amp can only give the sub 500 watts at the highest volume that I am likely to be listening.
That is why I cautioned you about ear protection...A 50 or 60 Hz test tone is VERY loud when you are pushing 500 watts worth of it to the sub
Before you start the process set all of the bass, trable, bass boost, mid range etc. settings to 0 or flat. Make sure the loudness or compression feature is turned off and any other distortion or synthesized settings(circle of sound) or whatever your head unit has then begin with a familiar song and turn it up untill it almost distorts and then set the gains.
You may want to make sure the crossovers on your 4 channel amp are set high enough to filter out most of the test tone to protect them after you set your volume with music and before you start your test tone.
As mentioned eariler, some or all JL amps and probably other brands allow you to set gains with no sub or dummy load attached to the amp. I think this is a nice feature.
To answer you question above...when the gains are properly set at the highest volume with no distortion it is matching the preamp voltage output from your head unit to the input on the amp properly to allow you to get all of the power to your particular sub choice that it should get utilizing a clean unclipped signal from your HU.
Does this make sense?
swez on 10/20/2007 05:31:07
Agree w/ James on gain setting. Most amps need a load to do this properly with a meter. (JL is one exception and may use an internal load system)
The "Dummy Load" test is the most reliable and accurate method and we don't need hearing protection for this one. (eD video mentioned earlier and linked below)
http://www.icixsound.com/iv/view_video.php?viewkey=929b125f8597834fa83a
When using a speaker/sub, the voice coil is the "LOAD". We can do this test the same way. The SPL level will be intense from the speaker, but if you lay the sub box face down on a carpeted surface, that will help mute the SPL and still get accurate results.
The last method is tuning by ear. This works fine if one knows the difference between clean tones and excessive distortion. It's interesting that many guys cannot hear the difference between clean and clipped audio until they have trained their ears to detect distortion.
Finally, one sure sign the amp is clipping badly, the amp cycles on/off when listening to heavy bass material. That says the amp is clipping badly and the gain is not set properly.
Swez
swez on 10/20/2007 05:36:40
Oh yea, setting the LPF, (Low Pass Filter) for a sub is easy.
For most daily driver bass systems, 80 Hz., is a good setting. This is good for 10's and 12" subs. If one wished to experiment a bit, try a range between 60 - 100 Hz. However, 80 Hz., is recommended for the typical bass system.
Swez
Replies (14)
gsandha99 on 10/15/2007 11:16:01
oh and one more thing. my amp has a 'bass expander function'...what the f' is that?
swez on 10/15/2007 17:59:32
The length of the post is OK, but the format is hard to read. Allow me to edit and answer your concerns:
Alright guys....i got lucky.....i got a new 10inch DVC 4 ohm Type S sub for a hundred bucks...they are last years model so they were selling them cheap......
So there i was, installing it into the box and my screw driver slipped...in my head, im thinking..nooooooooooo, as the screw driver creates an ever so small divet into the rubber around the sub.....now, this divet is extremely small and did not pierce through the rubber or anything to make a hole. So im thinking it should be fine...any suggestions though...would be appreciated.
[A thin dab of silicone sealer will often do the trick and flexes with the rubber too. Other glues are rigid when they cure and that would make a crusty spot too. Let the silicone cure for a few hours or use a hair drier on low heat, high air to speed up the curing process. If possible, try to do the repair on the under side of the surround. That way, the repair is invisible.]
...After it was installed, i drove around testing it at high volumes...and the amp shut off on me....because my amp is running this at 2ohms i realised i had forgot to readjust the gain...so i did that at it seems fine so far. But i have a question. I know that gain is essentially input sensitivity...right? so does that mean that a higher gain, means that the amp is working less because of a more clear signal or something?
[The amp gains are input sensitivity compensators. We use this feature to match the HU output voltage to the amp's input side. The best way to do this is with an AC volt meter and a reference level test tone of say 50 Hz., for subs. The sub is getting full power at 24.5 volts AC.]
Also, when i set the gain, i read a bunch of instrucitions which said to set all settings to zero or off etc. But what about the subwoofer control on the HU..if i set that to zero, then there is no signal being sent to the amp. So what i did, was set the subwoofer volume on the HU to 1...and set the gain using a DMM. but i have found that this is too loud at times and i cant go lower....so i just lowered the gain a bit to give my self some more lee-way....im thinking this should be fine, and ive turned off the bass boost so im hoping that amp doesnt go into shutdown mode again....i will test it later today.....
[Here's a video and written instructions on how to set amp gains. They used a resisitive load, but a sub will also work as a test load.]
http://www.clubknowledge.com/cgi-bin/car_audio_faq/faq.cgi?g4813
Also, i am having increased dimming issues becuase of the 2ohm load....i have decided to buy a red or yellow top this friday...I have heard that this will solve the problem...i upgraded my 2 ground wires in the 'big three' but did not do the positive wire because the alternator is extremely tough to reach....So my plan is to buy a red or yellow top on friday and see. What you guys think about all this...sorry for such a long post...
[Yes, light dimming will become an issue as the amp is now pulling 2x the power it did at 4 ohms. A higher CCA rated BAT will help. But, that power line between the ALT and + terminal of the BAT is also important to upgrade. Yes, it may be a pain to get to, but adding another wire to the stock one will lower resistance and allow more power to flow to the BAT. That's the most important line of a Big 3 upgrade.
In this small car, it might only have a #6-8 gage wire as stock. Adding another #4-8 gage line to this will maximize power flow from the ALT to BAT and reduce/eliminate dimming]
Swez
PS Avoid using bass boost and related circuits when possible. If used, a moderate boost of +3 to +6 dB boost is more than enough. Some Rap, Country & Hip-Hop songs have lots of bass juiced into the mix already. Rock, Classical and some Jazz music can use a little help as the bass is not so prominent This is where a little bass EQ can really help bring up the bass.
gsandha99 on 10/16/2007 11:28:17
Thanks a tonne swez...i really appreciate your long and thought out answers.
About the divet in the sub....It is reaaaalllly smaalll.....and i think i should leave it like that for fear of adding something not required at the moment.....i really dont think it will make a difference, or get bigger or anything...what do you think?
WHen you say, "The sub is getting full power at 24.5 volts AC." Are you saying that should be the maximum the sub is getting at any given volume/level? Because...if i set my gains to that...and i turn my volume up, the voltage increases...no? (i havent checked out the video yet, as i am at work, so if that answers the question..sorry).
With regards to dimming....I will be getting the red/yellow top for about 200 bucks this friday. I will try to save up some more from my budget and get the positive wire changed aswell....that will prolly be another 100 dollars, he was saying....but i know it will be well worth it...
And your right, i turned off the bass boost and bass expander...and it sounds much better...these settings were probably over exerting the amp anyways.
swez on 10/17/2007 05:44:16
That video explains amp gain adjustments it very well. (How to set gains properly) Just make note of the steps they use and then adjust the amp gain so that your sub is getting a solid 24-25 volts with a 50 Hz test tone. Doing this correctly will give the sub plenty of "clean" bass power on music that has strong bass tracks.
Defeating the bass expander circuit, prevents over-driving the amp. (This is commonly called "CLIPPING") We want to avoid clipping as it's hard on the sub and amp. (High distortion numbers means clipping) Most Bass Expander circuits can deliver up to +18dB of bass boost @ 45 Hz. This often means severe clipping and high distortion levels to the sub. (Don't use that feature unless you can manage the boost w/o clipping the amp signals to the sub)
Swez
gsandha99 on 10/17/2007 11:54:45
I find that when i properly adjust the gain on the amp to the proper voltoage, that my gain is very high...almost maximum...this also gives the bass sound less of a fullness and crispness in sound...its hard to describe, but it sounds more fluttery
But what i think i will do. Is lower the LPF to 55hz from where i had it at 85hz and see if that fixes the problem...suggestions?
swez on 10/17/2007 19:53:18
Hummm, your amp may be clipping and this will cause the bass to sound raspy and not clean and full. (Fuzzy or sloppy lows are common when the amp begins to clip)
Part of this is the sub size and perhaps the enclosure is not well suited to this sub either. This sub works best in a 0.85 ft^3 sealed box. It can handle a wider range, (0.65 - 1.5 ft^3) but as we go larger than 0.85, the lows are deeper, but not as much cone control and power handling.
What are the dimensions of your enclosure anyway?
Swez
jamesp on 10/18/2007 08:22:05
gsandha99,
Did you have the volume turned up to the point just below where distortion begins when you were measuring the AC voltage?
The video clip shows how to set the gains using a dummy load to represent the load the amp will "see" from the sub. A few amps allow you to set the gains without a load on the end of the speaker wires.
In you case you will probably have to have your sub connected, Play the test tone with no boost or cut as described eariler. Turn the volume up to the maximum level you can achieve with no distortion with your gain set low. Now rotate the gain knob while vwatching the volt meter....CAUTION.....you need some ear protection here...when I used a 60Hz tone at high volume setting my voltage to achieve 500 watts with a 2 Ohm load, it was vibrating my eyeballs...In my case my target AC voltage was around 31.6V ac which required about 3/4 of the travel of the gain knob. when I was close to the desired voltage needed I found that a very small increase in the gain control had much more affect on voltage than the same amount of travel had at lower gain settings.
I think my question to you is; did you set your gains with the head unit volume turned up about 75% or so or did you set it with the volume turned way down?
gsandha99 on 10/18/2007 15:28:33
Hey guys,
Swez...you know, im not sure how big my box is...its a wedge design. Sealed...seems like the standard size...not small..not big....how would i measure it?
James....you know..i didnt have the sub hooked up....so im guessing this is where the problem might lie.....i think your right about the load.....although would it make sense to turn down the gain and up the bass boost to achieve a better sound...or is this not a good idea...im asking if it is good to basically set it by ear....
swez on 10/18/2007 17:33:43
Use the link below to get a pretty close number on the internal volume of the enclosure you have. Just pick the shape of box, fill in the external dimensions & wood thickness as measured and the calculator will do the rest. (Wedge enclosure 1 or 2)
http://www.the12volt.com/caraudio/boxcalcs.asp
Once we know the internal airspace, subtract the sub displacement.
Displacement = 0.050 cu. ft. (0.05 ft^3 here) Then we know the actual internal airspace the sub is working within. Hopefully, the net airspace is under 1.0 ft^3, but larger than 0.70 ft^3.
Proper gain setting is a bit of an art form. We are balancing several parameters here to get it right. When using Bass Boost on some tunes, it's OK to go +3dB or a tad more on Rock and such. On Rap and other similar music, that may be too much as the amp will clip and the sub now sound like "hammered poop". 8~(
Swez
jamesp on 10/19/2007 07:29:40
Swez,
If he is setting the gain to the proper AC voltage with no load on the amp it wont even be close will it. I know that some JL amps will allow you to do this and probably others, but will his amp allow it. I dont know what amp he is using.
It seems that he adjusted his bass boost on the head unit to a setting of 1 and then had to turn the gain knob up almost all the way to get to the required AC voltage. If his amp requires a load to set the gain and he says he didnt have the sub hooked up so the gain setting is probably way to high, right,.......unless of course his amp doesnt require any load to set the input sensitivity.
added at 9:53am: I see that he is using a Kenwood KAC 8101 amp....can the gain be properly set with no load on the the amp output. If not, I suspect that the settings arrived at with no load are resulting in the dreaded square waveform syndrome as the AC voltage at the near maximum gain setting is probably much higher than what it needs to be. Whadduya think ?
gsandha99 on 10/19/2007 11:11:57
Also, the gain that is eventually set....is that amount of voltage a maximum that the amp should get? or is that the minimum...because if i turn up the sub control on HU or volume or w/e, it will obvy be pumping more voltage into the amp than what i originall set it too.
jamesp on 10/19/2007 14:48:52
Gsandha, when you properly adjust the gain, the AC voltage that you set is the voltage the amp sends to the sub to correspond to the RMS wattage of the load(sub) the amp sees.
That is why when you set the gain you first turn the volume up on the head unit to the loudest position that you will ever listen at or the loudest it will go without distorting(clipping)
Now you put your test tone disc into the player and let it play at the high volume that you previously set it at. Now measure the AC voltage at the sub channel speaker outputs with your meter.Start off with the gain at about the mid point and once you read the voltage, adjust the gain knob untill tou reach the target voltage.
For example: my Alpine type R sub is rated at 500 watts RMS and wired in parrallel for a 2 Ohm load. By doing the math or looking at a chart I determine that I need to see 31.6 volts ac at the speaker output in order to be sure that my amp can only give the sub 500 watts at the highest volume that I am likely to be listening.
That is why I cautioned you about ear protection...A 50 or 60 Hz test tone is VERY loud when you are pushing 500 watts worth of it to the sub
Before you start the process set all of the bass, trable, bass boost, mid range etc. settings to 0 or flat. Make sure the loudness or compression feature is turned off and any other distortion or synthesized settings(circle of sound) or whatever your head unit has then begin with a familiar song and turn it up untill it almost distorts and then set the gains.
You may want to make sure the crossovers on your 4 channel amp are set high enough to filter out most of the test tone to protect them after you set your volume with music and before you start your test tone.
As mentioned eariler, some or all JL amps and probably other brands allow you to set gains with no sub or dummy load attached to the amp. I think this is a nice feature.
To answer you question above...when the gains are properly set at the highest volume with no distortion it is matching the preamp voltage output from your head unit to the input on the amp properly to allow you to get all of the power to your particular sub choice that it should get utilizing a clean unclipped signal from your HU.
Does this make sense?
swez on 10/20/2007 05:31:07
Agree w/ James on gain setting. Most amps need a load to do this properly with a meter. (JL is one exception and may use an internal load system)
The "Dummy Load" test is the most reliable and accurate method and we don't need hearing protection for this one. (eD video mentioned earlier and linked below)
http://www.icixsound.com/iv/view_video.php?viewkey=929b125f8597834fa83a
When using a speaker/sub, the voice coil is the "LOAD". We can do this test the same way. The SPL level will be intense from the speaker, but if you lay the sub box face down on a carpeted surface, that will help mute the SPL and still get accurate results.
The last method is tuning by ear. This works fine if one knows the difference between clean tones and excessive distortion. It's interesting that many guys cannot hear the difference between clean and clipped audio until they have trained their ears to detect distortion.
Finally, one sure sign the amp is clipping badly, the amp cycles on/off when listening to heavy bass material. That says the amp is clipping badly and the gain is not set properly.
Swez
swez on 10/20/2007 05:36:40
Oh yea, setting the LPF, (Low Pass Filter) for a sub is easy.
For most daily driver bass systems, 80 Hz., is a good setting. This is good for 10's and 12" subs. If one wished to experiment a bit, try a range between 60 - 100 Hz. However, 80 Hz., is recommended for the typical bass system.
Swez
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