Hey all,
Long read... trying to be brief!
- I have a Kenwood KAC-7252 amp which is bridged (mono) giving me 1000 watts peak, 500RMS.
- I'm using a bassworx slot ported enclsure for a 12" sub. It's tuning Frequency is 38Hz.
- I'm using a Pioneer Premier DEH680MP head unit.
I managed to fry my Audiobahn AW122N 12" 1100w @ 550 RMS sub probably because I used too much bass boost. Its not dead... it just smoked up alot. Still seems to work but I am replacing the sub regardless.
I orignally purchased a 30KHz subsonic filter (the ones that plug in line with the RCA inputs to the amp) as my amp did not have subsonic filtering... So I used the 30KHz subsonic filter as a high pass filter, and set my head unit to about 100Hz for my low pass filter (80 - 120Hz was recommended by audiobahn).
The sub im getting is a Pioneer TS-W3002SPL.
http://www.pioneerelectronics.com/pna/v3/pg/product/details/0,,2076_4061_232689560,00.html
its a 2 ohm DVC, I was planning on running it in series with my amp bridged (1000peak 550RMS @ 4 ohm)
I have no clue if this sub is going to be alright with my 38Hz (tuning Freq) enclosure, but im going to try and make it work.
Now that im getting a new sub, I could use some advice on how to setup my high pass and low pass filter settings, and run my head and amp at safe levels for the sub. I would very much like to avoid frying my new sub !!!
My amp can set either a HPF or LPF ranging from 50 - 200 Hz
I still have the 30Hz In line filters as well.
My deck can set a HPF and a LPF (simultaniously or either or) within these presets: 50/63/80/100/125 Hz
so... which should I use to set a HPF and LPF? head unit or amp?
which HPF and LPF ranges should I aim for?
Sorry for the long post... im a noob at this stuff!!
Replies (8)
ShootuhMcBustaCap on 10/8/2006 22:48:46
Whattup Poke, I'm also a noob but I'll try to help. Your amp doens't match up to the specs of the sub very well, your RMS rating is little more than half that of the rated sub you plan to run. Peak is barely more than a third. That can cause problems, because if you set your gain too high to power the sub it can cause damage. The self proclaimed Dinosaurs of the baord may or may not dispute this, but from personal expeireince I have blown a sub because of this.
That is caused by distortion, clipping and things of such nature when your making the amp work harder than it can. Similar to a Taco Bell worker spitting in the beans, It decides the work load is too much, and decides that clipping, square wave and high thd levels (snicker) are It's way of getting even. Again This may be disputed by the Swez and the Brownstone, but this is my personal expeirence. setting the gain too high could have caused your Audiobahn's untimely demise. Check out www.BCAE1.com to learn more on that.
By the way, what crossover frequency did you use with the amp's low pass filter when you blew the Audiobahn? Did you use only the Head Units? A freind of mine has the same Pioneer, and it's internal crossovers don't seem to work very well.
As for your box, what is the size in cubic feet? That can make a huge difference in your Subs performance. Swez or somebody else can help you better with things of that nature, as that's not my field. I do know that a box built to specks rocks, as I built a bandpass box to speck for an Infinity Reference and it was awesome.
Hope I helped
Shootuh
swez on 10/9/2006 11:01:07
Agreed! That amp is solid up to ~500 watts RMS and will feed any medium-strong sub well, if we avoid excessive clipping, use proper enclosure designs and in vented enclosures, use an infrasonic filter.
Your settings appear to be correct on amp and adequate F-mod choice was used. (30 Hz, HPF) However, a 'smoked coil', is often a sign of too much heat and not enough speaker cone movement to keep it cool. This excess heat is often caused by a heavily clipped audio signal, coming from the amplifer. Improper amp gain settings are part of that. The other would be excessive bass boost. Combine them together and even a stout sub can be cooked in time.
Here are the specs for your Pioneer Sub. Note the power and enclosure recommendations for same. If we use a larger box than specified, the sub will still work OK, but power handling may suffer a bit, as the sub may reach X-max, (Max excursion range) well before maximum input power is applied.
http://www.pioneerelectronics.com/pna/v3/pg/product/details/0,,2076_4061_232689560_tab=B,00.html?compName=PNA_V3_ProductDetailsComponent
FYI: As I was reading your post, I saw Audiobahn sub all over the page even before getting to that detail. hehe These subs are notorious for failure as they seem not well designed for adequate cooling under severe conditions. The Pioneer is definitely a step up, but keep your amp from excess clipping.
Using an AC volt meter to measure your amp output will help. The target voltage for a 4 ohm sub and 500 watts of clean power, will be about 45 volts AC tops. If you see short/long peaks above that number, the amp is clipping!!! Avoid that and you should be just fine.
Do you have a link or specs for that sub enclosure mentioned? This one? (GP12 box?)
http://www.bassworx.com/pdfs/NA2005BassCatalog2005.pdf
If yes, this box should be fine for your Pioneer sub. Just make sure you set amp gains as noted earlier.
swez
pokesmot on 10/9/2006 15:35:36
thanks for the replies, I was only using an LPF of about 100Hz on the head, and nothing on the AMP when it blew.
as far as box size, it is in fact the bassworx GP12 enclosure; so the box is about 1.9 cubic feet. So I now know the box is good, thanks :)
as far as HPF, should I rely solely on the FMOD 30Hz filter? or should I set the amps 50 Hz HPF as well?
or should I just keep tweaking settings between the head and amp (withing previously mentioned specs) until I measure no more than 45 volts at the amp?
will go out and measure the voltage from the amp before I install the sub. Until then, I'll just stick to my cheap audiobahn... Kinda figured this sub was too good to be true!!
on a side note; is this a really crappy amp? should I invest in a mono class D amp that includes a subsonic filter, or should this amp be adequete? (in terms of getting the most out of my new sub)
thanks again for the replies!!!
-pokesmot
swez on 10/9/2006 16:35:10
Use the LPF on your amp for sub apps only. Set that between 80-100 Hz., and you'll block all signals above that range.
The F-Mods (HPF's) are there to block harmful lows, (below Tuning Freq) and passes everything above that. You are fine with what you have now.
Your HU HPF should be used if you have small format, full range speakers. Here's a general guideline for setting that feature: (Only for full range speakers, not sub apps)
4" Mids 200-300 Hz.
5.25" Mid/woofers 80-100 Hz.
6.5" Midbass/woofers 60-80 Hz.
The Kenwood is a decent amp and the newer ones seem to fudge a bit on real power ratings. Frankly, most amps are overrating now that we have CEA rated compliance rules. (RMS output = 1% THD, 14.4 volts as a supply voltage)
It would be best suited for modest sub applications below ~400 RMS @ 4 ohms when bridged to MONO. However, it makes for a very good full range amp for mids and highs.
If you really want a better sub amp, stick with Class D designs that deliver rated power like Alpine, Rockford, Kicker, JBL, Infinity, Crossfire and JL. (yes, there are MANY more too)
If on a tight budget, the Kenwood KAC-9152D. Here are the specs on it: It's a tad overrated too, but for well under $200.00, it is a pretty solid amp for that $$$.
http://www.cardomain.com/item/KENKAC9152D?ref=gogwr&utm_source=google&utm_medium=ppc&utm_term=kac-9152d
Best Prices:
http://www.google.com/search?sourceid=navclient&ie=UTF-8&rls=GGLG,GGLG:2005-41,GGLG:en&q=KAC%2d9152D
Comments?
swez
PS That sub and your present box should be fine. However, if you jump to a Class D amp, that can handle 1 ohm loads or like the JL Slash series, PG's Xenon Series and JBL's newest amp that delivers same power between 1.5-4.0 ohms.
pokesmot on 10/9/2006 19:56:54
thanks for the info on setting the head HPF. I have 6.5's and 6x9's so im going to go with either the 63 or 80Hz setting. (3 way fronts and 5 way rears)
the Kenwood KAC-9152D looks good.
if only I bought that instead of this KAC-7252 :(
If you had the pioneer sub I had, which amp would you pick? The kenwood, or would you save up and go for something better?
thanks again, your opinion is greatly appreciated!
-pokesmot
swez on 10/10/2006 16:57:28
Set the HPF for your full range speakers at 80 Hz., as this blocks the lows covered by the correct driver. (a subwoofer) If using the HU amps to power your main speakers, they will also get more clean power from the HU. (Not wasting power on frequencies below 80 Hz.)
The sub amp LPF can now be set at 80 Hz., and your 30 Hz., F-Mods will block harmful lows to a ported sub as mentioned before. (This is basically an active BP filter network.)
Consider using that KAC-7252 as a full range power amp (80-20,000 Hz.) for your front & rear speakers. Here, to get decent balance between F & R speakers, we can use power resistors to tone down the rear speakers to desired levels that balance out F & R staging.
What is the make & model # on your front and rear speakers? Am curious how much RMS power they can take...
swez
pokesmot on 10/13/2006 10:24:04
UGH Just finished typing a long reply and it got cleared when I submitted...
Front and rears are both pioneer
Front - TS-A641P 50 watts RMS / 260 max
http://www.pioneerelectronics.com/pna/v3/pg/product/details/0,,2076_310069906_191756363,00.html
my amp will probably kill these speakers. both are 4 0hm.
thanks again
-pokesmot
Rear - TS-A6991R 80 watts RMS / 460 max
http://www.pioneerelectronics.com/pna/v3/pg/product/details/0,,2076_310069902_168472238,00.html
swez on 10/13/2006 11:46:04
Not if you used -3dB attenuators on the input side of the amp and are very prudent with gain settings.
I believe most Premier HU's are 4 volt preouts. If we used 3dB attenualtors, this would cut your amp output and power consumption by ~50% and would be safe for your Pioneer speakers too. (Output would now be ~2 volts and set gain at 4 volts)
These F-Mods should do the trick:
http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=266-240
Understand what I just offered you as an option? (A 1:2 ratio gain structure)
swez
Long read... trying to be brief!
- I have a Kenwood KAC-7252 amp which is bridged (mono) giving me 1000 watts peak, 500RMS.
- I'm using a bassworx slot ported enclsure for a 12" sub. It's tuning Frequency is 38Hz.
- I'm using a Pioneer Premier DEH680MP head unit.
I managed to fry my Audiobahn AW122N 12" 1100w @ 550 RMS sub probably because I used too much bass boost. Its not dead... it just smoked up alot. Still seems to work but I am replacing the sub regardless.
I orignally purchased a 30KHz subsonic filter (the ones that plug in line with the RCA inputs to the amp) as my amp did not have subsonic filtering... So I used the 30KHz subsonic filter as a high pass filter, and set my head unit to about 100Hz for my low pass filter (80 - 120Hz was recommended by audiobahn).
The sub im getting is a Pioneer TS-W3002SPL.
http://www.pioneerelectronics.com/pna/v3/pg/product/details/0,,2076_4061_232689560,00.html
its a 2 ohm DVC, I was planning on running it in series with my amp bridged (1000peak 550RMS @ 4 ohm)
I have no clue if this sub is going to be alright with my 38Hz (tuning Freq) enclosure, but im going to try and make it work.
Now that im getting a new sub, I could use some advice on how to setup my high pass and low pass filter settings, and run my head and amp at safe levels for the sub. I would very much like to avoid frying my new sub !!!
My amp can set either a HPF or LPF ranging from 50 - 200 Hz
I still have the 30Hz In line filters as well.
My deck can set a HPF and a LPF (simultaniously or either or) within these presets: 50/63/80/100/125 Hz
so... which should I use to set a HPF and LPF? head unit or amp?
which HPF and LPF ranges should I aim for?
Sorry for the long post... im a noob at this stuff!!
Replies (8)
ShootuhMcBustaCap on 10/8/2006 22:48:46
Whattup Poke, I'm also a noob but I'll try to help. Your amp doens't match up to the specs of the sub very well, your RMS rating is little more than half that of the rated sub you plan to run. Peak is barely more than a third. That can cause problems, because if you set your gain too high to power the sub it can cause damage. The self proclaimed Dinosaurs of the baord may or may not dispute this, but from personal expeireince I have blown a sub because of this.
That is caused by distortion, clipping and things of such nature when your making the amp work harder than it can. Similar to a Taco Bell worker spitting in the beans, It decides the work load is too much, and decides that clipping, square wave and high thd levels (snicker) are It's way of getting even. Again This may be disputed by the Swez and the Brownstone, but this is my personal expeirence. setting the gain too high could have caused your Audiobahn's untimely demise. Check out www.BCAE1.com to learn more on that.
By the way, what crossover frequency did you use with the amp's low pass filter when you blew the Audiobahn? Did you use only the Head Units? A freind of mine has the same Pioneer, and it's internal crossovers don't seem to work very well.
As for your box, what is the size in cubic feet? That can make a huge difference in your Subs performance. Swez or somebody else can help you better with things of that nature, as that's not my field. I do know that a box built to specks rocks, as I built a bandpass box to speck for an Infinity Reference and it was awesome.
Hope I helped
Shootuh
swez on 10/9/2006 11:01:07
Agreed! That amp is solid up to ~500 watts RMS and will feed any medium-strong sub well, if we avoid excessive clipping, use proper enclosure designs and in vented enclosures, use an infrasonic filter.
Your settings appear to be correct on amp and adequate F-mod choice was used. (30 Hz, HPF) However, a 'smoked coil', is often a sign of too much heat and not enough speaker cone movement to keep it cool. This excess heat is often caused by a heavily clipped audio signal, coming from the amplifer. Improper amp gain settings are part of that. The other would be excessive bass boost. Combine them together and even a stout sub can be cooked in time.
Here are the specs for your Pioneer Sub. Note the power and enclosure recommendations for same. If we use a larger box than specified, the sub will still work OK, but power handling may suffer a bit, as the sub may reach X-max, (Max excursion range) well before maximum input power is applied.
http://www.pioneerelectronics.com/pna/v3/pg/product/details/0,,2076_4061_232689560_tab=B,00.html?compName=PNA_V3_ProductDetailsComponent
FYI: As I was reading your post, I saw Audiobahn sub all over the page even before getting to that detail. hehe These subs are notorious for failure as they seem not well designed for adequate cooling under severe conditions. The Pioneer is definitely a step up, but keep your amp from excess clipping.
Using an AC volt meter to measure your amp output will help. The target voltage for a 4 ohm sub and 500 watts of clean power, will be about 45 volts AC tops. If you see short/long peaks above that number, the amp is clipping!!! Avoid that and you should be just fine.
Do you have a link or specs for that sub enclosure mentioned? This one? (GP12 box?)
http://www.bassworx.com/pdfs/NA2005BassCatalog2005.pdf
If yes, this box should be fine for your Pioneer sub. Just make sure you set amp gains as noted earlier.
swez
pokesmot on 10/9/2006 15:35:36
thanks for the replies, I was only using an LPF of about 100Hz on the head, and nothing on the AMP when it blew.
as far as box size, it is in fact the bassworx GP12 enclosure; so the box is about 1.9 cubic feet. So I now know the box is good, thanks :)
as far as HPF, should I rely solely on the FMOD 30Hz filter? or should I set the amps 50 Hz HPF as well?
or should I just keep tweaking settings between the head and amp (withing previously mentioned specs) until I measure no more than 45 volts at the amp?
will go out and measure the voltage from the amp before I install the sub. Until then, I'll just stick to my cheap audiobahn... Kinda figured this sub was too good to be true!!
on a side note; is this a really crappy amp? should I invest in a mono class D amp that includes a subsonic filter, or should this amp be adequete? (in terms of getting the most out of my new sub)
thanks again for the replies!!!
-pokesmot
swez on 10/9/2006 16:35:10
Use the LPF on your amp for sub apps only. Set that between 80-100 Hz., and you'll block all signals above that range.
The F-Mods (HPF's) are there to block harmful lows, (below Tuning Freq) and passes everything above that. You are fine with what you have now.
Your HU HPF should be used if you have small format, full range speakers. Here's a general guideline for setting that feature: (Only for full range speakers, not sub apps)
4" Mids 200-300 Hz.
5.25" Mid/woofers 80-100 Hz.
6.5" Midbass/woofers 60-80 Hz.
The Kenwood is a decent amp and the newer ones seem to fudge a bit on real power ratings. Frankly, most amps are overrating now that we have CEA rated compliance rules. (RMS output = 1% THD, 14.4 volts as a supply voltage)
It would be best suited for modest sub applications below ~400 RMS @ 4 ohms when bridged to MONO. However, it makes for a very good full range amp for mids and highs.
If you really want a better sub amp, stick with Class D designs that deliver rated power like Alpine, Rockford, Kicker, JBL, Infinity, Crossfire and JL. (yes, there are MANY more too)
If on a tight budget, the Kenwood KAC-9152D. Here are the specs on it: It's a tad overrated too, but for well under $200.00, it is a pretty solid amp for that $$$.
http://www.cardomain.com/item/KENKAC9152D?ref=gogwr&utm_source=google&utm_medium=ppc&utm_term=kac-9152d
Best Prices:
http://www.google.com/search?sourceid=navclient&ie=UTF-8&rls=GGLG,GGLG:2005-41,GGLG:en&q=KAC%2d9152D
Comments?
swez
PS That sub and your present box should be fine. However, if you jump to a Class D amp, that can handle 1 ohm loads or like the JL Slash series, PG's Xenon Series and JBL's newest amp that delivers same power between 1.5-4.0 ohms.
pokesmot on 10/9/2006 19:56:54
thanks for the info on setting the head HPF. I have 6.5's and 6x9's so im going to go with either the 63 or 80Hz setting. (3 way fronts and 5 way rears)
the Kenwood KAC-9152D looks good.
if only I bought that instead of this KAC-7252 :(
If you had the pioneer sub I had, which amp would you pick? The kenwood, or would you save up and go for something better?
thanks again, your opinion is greatly appreciated!
-pokesmot
swez on 10/10/2006 16:57:28
Set the HPF for your full range speakers at 80 Hz., as this blocks the lows covered by the correct driver. (a subwoofer) If using the HU amps to power your main speakers, they will also get more clean power from the HU. (Not wasting power on frequencies below 80 Hz.)
The sub amp LPF can now be set at 80 Hz., and your 30 Hz., F-Mods will block harmful lows to a ported sub as mentioned before. (This is basically an active BP filter network.)
Consider using that KAC-7252 as a full range power amp (80-20,000 Hz.) for your front & rear speakers. Here, to get decent balance between F & R speakers, we can use power resistors to tone down the rear speakers to desired levels that balance out F & R staging.
What is the make & model # on your front and rear speakers? Am curious how much RMS power they can take...
swez
pokesmot on 10/13/2006 10:24:04
UGH Just finished typing a long reply and it got cleared when I submitted...
Front and rears are both pioneer
Front - TS-A641P 50 watts RMS / 260 max
http://www.pioneerelectronics.com/pna/v3/pg/product/details/0,,2076_310069906_191756363,00.html
my amp will probably kill these speakers. both are 4 0hm.
thanks again
-pokesmot
Rear - TS-A6991R 80 watts RMS / 460 max
http://www.pioneerelectronics.com/pna/v3/pg/product/details/0,,2076_310069902_168472238,00.html
swez on 10/13/2006 11:46:04
Not if you used -3dB attenuators on the input side of the amp and are very prudent with gain settings.
I believe most Premier HU's are 4 volt preouts. If we used 3dB attenualtors, this would cut your amp output and power consumption by ~50% and would be safe for your Pioneer speakers too. (Output would now be ~2 volts and set gain at 4 volts)
These F-Mods should do the trick:
http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=266-240
Understand what I just offered you as an option? (A 1:2 ratio gain structure)
swez
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