How many chips + filter capacitance to be be used to get kickdrum bass to be tight...
I read many reviews that these amps are not muscle amps and are weak at producing tight bass is it true?
can anybody give suggestions that how to achieve bass as tight as using Bryston 4BSST amps or so?
please help me...
thanks,
Ken
I read many reviews that these amps are not muscle amps and are weak at producing tight bass is it true?
can anybody give suggestions that how to achieve bass as tight as using Bryston 4BSST amps or so?
please help me...
thanks,
Ken
Let me tell u my actual loudspeaker configuration..
1.1 inch dual concentric tweeter
6.5 inch mid-bass from wavecor
10 inch Scanspeak 26W Revelator woofer..
now I want to drive the speaker which can easily serve enough power.
I read reviews about Jeff Rowland Concentra with Wisdom Audio M-50 where a 12 inch UNderHung voice coild woofer is being driven by the amp which has 6 chips in BPA config but there was no slam but still the amp was giving enough power. But I really need to calculate the figures...
Jeff Rowland himself said that no speaker can take beyond 8 amps of continuous current since the voice coil wire guage itself cant pickup that huge amount of current. So he said it serves the purpose...
Some people say that Jeff Rowland Model amps and Concentra are atmost performing amps which has LM3886 chips in their model...
http://www.audioasylum.com/forums/amp/messages/7578.html
Here the only doubt is that how to get that slam from the chip amps...
I finall thought to build a 8 chips in BPA 400 configuration so that the amp can feed atleast 1 amp of continous power to feed my speaker.
I was planning to buy Bryston but after reading review of
http://www.audioasylum.com/forums/amp/messages/7578.html
I just step back since It looked foolishness to spend arround 3000 Pounds for an amp where one can build a superb amp like concentra for a very fraction of price..
JUST JUST JUST one thing which bothers me is the bass.. since I will be using Scanspeak 10 inch Revelator woofers it sucks tons of current from the amp.
Any professional please guide me...
I am planning to build either of the following...
BPA 300 with 6 chips in bridged and parallel + with 47,000 ufd for all chips...
BPA 400 with 8 chips in same config as above with 60,000ufd
my problem is not something that i will be always banging at full volume but even at the lower volumes the bass should be tight enough..
ANY experts please guide me...
1.1 inch dual concentric tweeter
6.5 inch mid-bass from wavecor
10 inch Scanspeak 26W Revelator woofer..
now I want to drive the speaker which can easily serve enough power.
I read reviews about Jeff Rowland Concentra with Wisdom Audio M-50 where a 12 inch UNderHung voice coild woofer is being driven by the amp which has 6 chips in BPA config but there was no slam but still the amp was giving enough power. But I really need to calculate the figures...
Jeff Rowland himself said that no speaker can take beyond 8 amps of continuous current since the voice coil wire guage itself cant pickup that huge amount of current. So he said it serves the purpose...
Some people say that Jeff Rowland Model amps and Concentra are atmost performing amps which has LM3886 chips in their model...
http://www.audioasylum.com/forums/amp/messages/7578.html
Here the only doubt is that how to get that slam from the chip amps...
I finall thought to build a 8 chips in BPA 400 configuration so that the amp can feed atleast 1 amp of continous power to feed my speaker.
I was planning to buy Bryston but after reading review of
http://www.audioasylum.com/forums/amp/messages/7578.html
I just step back since It looked foolishness to spend arround 3000 Pounds for an amp where one can build a superb amp like concentra for a very fraction of price..
JUST JUST JUST one thing which bothers me is the bass.. since I will be using Scanspeak 10 inch Revelator woofers it sucks tons of current from the amp.
Any professional please guide me...
I am planning to build either of the following...
BPA 300 with 6 chips in bridged and parallel + with 47,000 ufd for all chips...
BPA 400 with 8 chips in same config as above with 60,000ufd
my problem is not something that i will be always banging at full volume but even at the lower volumes the bass should be tight enough..
ANY experts please guide me...
Hi rhythmdiy,
I suppose you are using a Scan Speak 26W/4867T00 woofer which can be seen here http://www.bmm-shop.nl/Product.asp?Product_ID=4683
You don´t give us much information about your loudspeakers, are they diy ones? BR enclosures? Volume used? In case they are diy ones have you measured the woofer for T/S parameters?
The data sheet for the above driver says a VAS of 223 l but the measurement in the German Klang&Ton shows 148 l . Qts doesn´t differ much 0,3 vs 032 and a Fs of 18.75 Hz vs 18 Hz is noting to write home about. But the difference in VAS is more than I would have accepted. BTW I have rejected Scan Speak drivers because of the vast tolerances that shows up and not just in this case.
If you are a well-known manufacturer (like a Swedish one) you may return the unacceptable ones, but they may hit the diy market instead.
I´m very interested in rhythmical music as reggae and afro music.
The reproduction of the bass notes are essential; improvements here have a synergistic effect on the mid range and high frequencies as well. But it´s also the other way around. You can´t look at one parameter more than temporary if you are going to succeed!
You may or may not be on the right track when you concentrate on the amp. My guess is that you overlook a few other important things.
I can only give you some hints of how to achieve a dynamic sound for the bass.
Use DC coupled amps, because phase errors add to each other in a system. If you need a high pass filter such as a rumble filter keep it in the "turntable chain".
Use an active filter for the bass amp and hence the woofer, any coil between the amp and the woofer will consume energy.
Room acoustics and speaker placement and listening position will be of very much importance. Room treatment such as bass traps is necessary in most rooms. You can equalize some but it wan´t help to solve a fundamental problem with room modes.
Decouple the speaker from the floor so that the floor doesn´t act as a delayed sound source. I use feet called the SD-feet and this is a big improvement as the concrete floor is more "silent" now.
Think of the system as precisely what it is; a rather complicated system where you have to focus on the totality.
Your amplifier hypothesis may be verified or not if you borrow a really potent power amp to start with. It´s probably not only a question of delivering enough power but how to handle the back-EMF from the speaker as well.
Eight amperes? It depends on so many things I´m always sceptical about such figures. For how long duration? Does it apply to big PA drivers as well?
I suppose you are using a Scan Speak 26W/4867T00 woofer which can be seen here http://www.bmm-shop.nl/Product.asp?Product_ID=4683
You don´t give us much information about your loudspeakers, are they diy ones? BR enclosures? Volume used? In case they are diy ones have you measured the woofer for T/S parameters?
The data sheet for the above driver says a VAS of 223 l but the measurement in the German Klang&Ton shows 148 l . Qts doesn´t differ much 0,3 vs 032 and a Fs of 18.75 Hz vs 18 Hz is noting to write home about. But the difference in VAS is more than I would have accepted. BTW I have rejected Scan Speak drivers because of the vast tolerances that shows up and not just in this case.
If you are a well-known manufacturer (like a Swedish one) you may return the unacceptable ones, but they may hit the diy market instead.
I´m very interested in rhythmical music as reggae and afro music.
The reproduction of the bass notes are essential; improvements here have a synergistic effect on the mid range and high frequencies as well. But it´s also the other way around. You can´t look at one parameter more than temporary if you are going to succeed!
You may or may not be on the right track when you concentrate on the amp. My guess is that you overlook a few other important things.
I can only give you some hints of how to achieve a dynamic sound for the bass.
Use DC coupled amps, because phase errors add to each other in a system. If you need a high pass filter such as a rumble filter keep it in the "turntable chain".
Use an active filter for the bass amp and hence the woofer, any coil between the amp and the woofer will consume energy.
Room acoustics and speaker placement and listening position will be of very much importance. Room treatment such as bass traps is necessary in most rooms. You can equalize some but it wan´t help to solve a fundamental problem with room modes.
Decouple the speaker from the floor so that the floor doesn´t act as a delayed sound source. I use feet called the SD-feet and this is a big improvement as the concrete floor is more "silent" now.
Think of the system as precisely what it is; a rather complicated system where you have to focus on the totality.
Your amplifier hypothesis may be verified or not if you borrow a really potent power amp to start with. It´s probably not only a question of delivering enough power but how to handle the back-EMF from the speaker as well.
Eight amperes? It depends on so many things I´m always sceptical about such figures. For how long duration? Does it apply to big PA drivers as well?
Im not an expert in that way that Im able to calculate stuff in the advanced way in theory like our good source AndrewT and others. Im more of a build-and-see-guy, but this is my experiance.
2 pieces of this boards bridged:
together with an unregulated power supply ( => 1000VA) and 47000uF/channel, is able to deliver a punchy rappid bass that I think would live up to your demands.
I've been using this for a week now and the bass is deep, natural and does not take over the sound (witch I hate), until it's really meant to. I have been making many different amps and my experiance is that bridge/parallel-config together with a heavy powersupply gives best performance.
2 pieces of this boards bridged:
An externally hosted image should be here but it was not working when we last tested it.
together with an unregulated power supply ( => 1000VA) and 47000uF/channel, is able to deliver a punchy rappid bass that I think would live up to your demands.
I've been using this for a week now and the bass is deep, natural and does not take over the sound (witch I hate), until it's really meant to. I have been making many different amps and my experiance is that bridge/parallel-config together with a heavy powersupply gives best performance.
Hello All,
It is sounding to me (no pun intended ) like everyone who has posted to far has plenty of amp, with plenty of speed. One thing concerning the huge amount of capacitance some of you are using: Are the caps a bank of smaller ones, or are some of you using a single 47,000uf cap?
A bank of smaller caps is faster! For instance, if I wanted 10,000uf of capacitance on each rail of a power supply, I wouldn't use a pair of 10,000uf caps. I would use 2 pairs of 2200uf, and 2 pairs of 3300uf.
Another thing that hasn't been mentioned yet as far as correctness of bass is concerned: Make sure the signal is getting to your speakers in the correct polarity! In the real, acoustic, world the beginning of any acoustic sound begins with a pressure wave. To reproduce it accurately via electronics, a pressure wave will be recorded as a positive rise in current, and the rarefaction immediately after the pressure wave will be recorded as a dip towards the negative rail. You have to make sure that when your system is trying to play back that pressure wave, it is pushing the speaker cone OUT, not pulling it in. That's why the pressure wave is recorded as a positive rise in current!
Now, does checking polarity involve doing complicated tests? No. You can do it that way if you like, but simply swap the connections on the back of your speaker, red for black, on BOTH speakers. If suddenly the bass sounds correct, especially on a bass, or kick, drum you have found the issue. The fix? If you only listen to one source, you're done!
If you listen to more than one source, here's a hint: Most CD players invert polarity. A correctly set up turntable does not. Tuners generally do not. Tape decks generally do not, but that depends on what was used to record the tape. The iPod inverts.
There are many solutions, of varying degrees of cost and difficulty, but there are many nice preamps out there that can handle the problem on the fly, by pressing one button, even though sometimes that button is incorrectly labeled "phase invert".
Don Taylor
BrassTeacher
It is sounding to me (no pun intended
) like everyone who has posted to far has plenty of amp, with plenty of speed. One thing concerning the huge amount of capacitance some of you are using: Are the caps a bank of smaller ones, or are some of you using a single 47,000uf cap?A bank of smaller caps is faster! For instance, if I wanted 10,000uf of capacitance on each rail of a power supply, I wouldn't use a pair of 10,000uf caps. I would use 2 pairs of 2200uf, and 2 pairs of 3300uf.
Another thing that hasn't been mentioned yet as far as correctness of bass is concerned: Make sure the signal is getting to your speakers in the correct polarity! In the real, acoustic, world the beginning of any acoustic sound begins with a pressure wave. To reproduce it accurately via electronics, a pressure wave will be recorded as a positive rise in current, and the rarefaction immediately after the pressure wave will be recorded as a dip towards the negative rail. You have to make sure that when your system is trying to play back that pressure wave, it is pushing the speaker cone OUT, not pulling it in. That's why the pressure wave is recorded as a positive rise in current!
Now, does checking polarity involve doing complicated tests? No. You can do it that way if you like, but simply swap the connections on the back of your speaker, red for black, on BOTH speakers. If suddenly the bass sounds correct, especially on a bass, or kick, drum you have found the issue. The fix? If you only listen to one source, you're done!
If you listen to more than one source, here's a hint: Most CD players invert polarity. A correctly set up turntable does not. Tuners generally do not. Tape decks generally do not, but that depends on what was used to record the tape. The iPod inverts.
There are many solutions, of varying degrees of cost and difficulty, but there are many nice preamps out there that can handle the problem on the fly, by pressing one button, even though sometimes that button is incorrectly labeled "phase invert".
Don Taylor
BrassTeacher
A check list to eliminate possible faults may be a good thing. The problem can be up to a few things that together contribute to the non optimal sound. Or it can of course be up to one important factor like the power amp isn´t capable of delivering the current needed.
Fault finding usually takes time because you have to check the possible errors that have some sort of hierarchy in your mind in order of probability. But in reality, the order can be reversed so the fault that was the last on your list was the one you should have started with.
Excuse me for being a bit theoretical, I am still not convinced that the problem is due to too little current when driving the speakers.
I can be wrong about this, but speakers and especially the cooperation between the drivers is crucial. In addition the woofer has to return fast enough after the pulse of e.g. a kick drum. The used woofer has a relatively high Cms value of 0.9 which means the suspension is soft. This also leads to the low Fs of 18 Hz.
I read about the claims made by Talon ( a loudspeaker manufacturer) some years ago, that a low Fs isn´t always a good thing because the cone of the woofer has not much support from the suspension to return to rest, and thus has to rely solely on the current driving the voice coil.
It´s true that different amps have different abilities to control the drivers of a loudspeaker. Damping factor is a somewhat complicated matter and has been discussed on this forum.
I can only advise you to check the hypothesis that the problem is caused by the amp. Try to borrow an amp that has a documented ability to produce kick drum bass.
It´s much about synergy so what one person reports about an amp is not generally true. Hi-fi magazines often make claims that are not valid.
Fault finding usually takes time because you have to check the possible errors that have some sort of hierarchy in your mind in order of probability. But in reality, the order can be reversed so the fault that was the last on your list was the one you should have started with.
Excuse me for being a bit theoretical, I am still not convinced that the problem is due to too little current when driving the speakers.
I can be wrong about this, but speakers and especially the cooperation between the drivers is crucial. In addition the woofer has to return fast enough after the pulse of e.g. a kick drum. The used woofer has a relatively high Cms value of 0.9 which means the suspension is soft. This also leads to the low Fs of 18 Hz.
I read about the claims made by Talon ( a loudspeaker manufacturer) some years ago, that a low Fs isn´t always a good thing because the cone of the woofer has not much support from the suspension to return to rest, and thus has to rely solely on the current driving the voice coil.
It´s true that different amps have different abilities to control the drivers of a loudspeaker. Damping factor is a somewhat complicated matter and has been discussed on this forum.
I can only advise you to check the hypothesis that the problem is caused by the amp. Try to borrow an amp that has a documented ability to produce kick drum bass.
It´s much about synergy so what one person reports about an amp is not generally true. Hi-fi magazines often make claims that are not valid.
As with all chipamps, they are very limited with impule current delivery. You should at least parallel 2 or more of them if you wan't them to perform on par with Scan-Speak Units...
As of now I don't think that much capacitance in the PSU will help that much. Just look that at least 100uF are placed as close as possible with thick traces to the chip's. Maybe 1uF film caps directly at the power pins....
As of now I don't think that much capacitance in the PSU will help that much. Just look that at least 100uF are placed as close as possible with thick traces to the chip's. Maybe 1uF film caps directly at the power pins....
Thanks alot for the replies.
My major doubt is this one..
""Or it can of course be up to one important factor like the power amp isn´t capable of delivering the current needed. "" first I want to bridge that gap.
So what I am planning to use is use 1000uf caps in 60 units for each channel so that the recharge time is fast enough and then stores up quickly...as well as supplies such a current that fast...
But my doubt comes from even reviews where they claim on Jeff Rowland Concentra and Model 10, 12 that the bass is not punchy enough.
So I was worried to drive big drivers with it...
But If I look at stereotimes review where Jeff Rowland 112 is being used to drive a Wisdom Audio m 50 with a massive 12 inch woofer and he claims that the soundstage was never tend to shrink even at higher volume...
It was very impressive but there are more negatives about the bass on the reviews...
I will be keeping lower -3db cuttoff at 8hz
what do u say guys any further discussions ....
My major doubt is this one..
""Or it can of course be up to one important factor like the power amp isn´t capable of delivering the current needed. "" first I want to bridge that gap.
So what I am planning to use is use 1000uf caps in 60 units for each channel so that the recharge time is fast enough and then stores up quickly...as well as supplies such a current that fast...
But my doubt comes from even reviews where they claim on Jeff Rowland Concentra and Model 10, 12 that the bass is not punchy enough.
So I was worried to drive big drivers with it...
But If I look at stereotimes review where Jeff Rowland 112 is being used to drive a Wisdom Audio m 50 with a massive 12 inch woofer and he claims that the soundstage was never tend to shrink even at higher volume...
It was very impressive but there are more negatives about the bass on the reviews...
I will be keeping lower -3db cuttoff at 8hz
what do u say guys any further discussions ....
The Linn Klimax Twin uses three chip amps per channel and a SMPS. Many seem to be happy with it. There are many review for instance this one.
http://www.avrev.com/home-theater-p.../linn-klimax-twin-stereo-power-amplifier.html
http://www.avrev.com/home-theater-p.../linn-klimax-twin-stereo-power-amplifier.html
big drivers are usually more efficient than small drivers.rhythmdiy said:
A more efficient big driver will deliver better bass than a smaller less efficient driver.
I consider F-3db=8Hz for the input filter to be too high.
I usually recommend that the input filter F-3db<=2Hz.
The NFB filter MUST be set lower than this and the PSU effective filter frequency must be lower than both.
I can only comment from mexperience with my chipamp, and my B&W P4's..
It has a hefty psu (around 20000 uF on each rail, and a high current pair of bridge rectifiers). Could it do kick drum.. Hell YES.
You'd feel the 'pressure' transient, and be able to hear clearly the decayof the strike on the skin.
The chip amps dont do 'bloomy' bass - if you're after a tight, fast, *accurate* sound, they excel.
You'll find that things get muddy when you:-
1/ parallel lots of chips
2/ dont match up resistors and caps
3/ drive the input closer to the max - I personally stick with a 'lower' output from my preamp (around 1V rms), and allow myself 3db of power amp continuous operation headroom.
25W of uncompressed clean power, with another 25W of transient capability is PLENTY loud enough for me - and that is deliverable by one chip...
I say build one to Nuuk's design using a single chip, keep the volume control in 'sensible' bounds, and prepare to be astounded.
Have fun
Owen
It has a hefty psu (around 20000 uF on each rail, and a high current pair of bridge rectifiers). Could it do kick drum.. Hell YES.
You'd feel the 'pressure' transient, and be able to hear clearly the decayof the strike on the skin.
The chip amps dont do 'bloomy' bass - if you're after a tight, fast, *accurate* sound, they excel.
You'll find that things get muddy when you:-
1/ parallel lots of chips
2/ dont match up resistors and caps
3/ drive the input closer to the max - I personally stick with a 'lower' output from my preamp (around 1V rms), and allow myself 3db of power amp continuous operation headroom.
25W of uncompressed clean power, with another 25W of transient capability is PLENTY loud enough for me - and that is deliverable by one chip...
I say build one to Nuuk's design using a single chip, keep the volume control in 'sensible' bounds, and prepare to be astounded.
Have fun
Owen
Hi All,
I'm not too knowlegable on amp design, I use a chip amp with 7480's and a bank of 1000 uF caps which works for me.
What I am somewhat familiar with is speaker building. Have you tried driving just one speaker with your amp? What was the bass like in that configuration? The reason I ask is that, while browsing through this thread I didn't notice anyone mention trying this. If your woofers are out of phase from one speaker to the other it will cancel "A LOT" of bass. If you try only one speaker connected to the amp and then only the other one by itself and both have better bass than you've had before, then one speaker's woofer is out of phase.
BTW: I happen to know this is easy to do, some very well known pro designers have done just that and it took some time to figure out! It's easy to troubleshoot and fix once you consider the possibility that, in spite of one's ego, anyone can make a mistake.
Try the above and see what the results are. Good Luck!
Best Regards,
TerryO
I'm not too knowlegable on amp design, I use a chip amp with 7480's and a bank of 1000 uF caps which works for me.
What I am somewhat familiar with is speaker building. Have you tried driving just one speaker with your amp? What was the bass like in that configuration? The reason I ask is that, while browsing through this thread I didn't notice anyone mention trying this. If your woofers are out of phase from one speaker to the other it will cancel "A LOT" of bass. If you try only one speaker connected to the amp and then only the other one by itself and both have better bass than you've had before, then one speaker's woofer is out of phase.
BTW: I happen to know this is easy to do, some very well known pro designers have done just that and it took some time to figure out! It's easy to troubleshoot and fix once you consider the possibility that, in spite of one's ego, anyone can make a mistake.
Try the above and see what the results are. Good Luck!
Best Regards,
TerryO
weissi said:
I agree. If you want real kickbass try adding a pair of these to your setup:
http://www.speakerplans.com/index.php?id=hd15horn
Astounding speakers in that department.
I think its possibly not the amp that is the problem...
rhythmdiy said:
I don't get this. Big drivers are usually much easier to drive.
At the time when i had the unavoidable five minute fling with chip amps none could produce acceptable bass from my speakers, irrespective of PS capacitance. Even anaemic PP tube amps were more convincing, let alone real solid state amps. Unusually speaker dependable.
The fact that so many non-commercial reviews agree about the JR bass probably means something.
analog_sa said:
My experience has been somewhat different as I've found my 7480 based chipamp to equal or nearly equal my Sansui AU-7900 integrated amp in the bass registers. Since they're both about 70 watts, I wouldn't think that either one would have problems with insufficient power, at least at the levels I listen to music.
As there are so many varieties of chipamp designs, it's awfully hard to make a blanket statement encompassing a whole plethora of different designs, topographies and layouts. It may be that the chipamp doesn't synergize with the preamp, I've noticed on mine, that a "passive preamp" really isn't a good match, although the impedance matching may account for a lot of it.
Back to our friend's bass problem, he should try a buddy's conventional amp to determine if, in fact, that he has an amp problem. The short-cut that I mentioned above was to eliminate the possibility of a miss-wired woofer on one of the speakers. It would certainly cause any speaker to sound bass shy as the out of phase bass notes would cancel each other to a great extent. If driving one speaker at a time gives greater bass output that both driven together then he needs to check the wiring to the woofers and determine which one is out of phase.
Until all possible errors are factored out, it doesn't make much sense to recommend any changes to the system.
Best Regards,
TerryO
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