Sometimes you can get lost in all the technical details and fail to see the forest for the trees ... or maybe fail to hear the sound for the electronics ...
No one really knows exactly what from a technical point of view exactly relates to perception
So I pose the question - who has actually done blind AB testing? Or at least a fair side by side comparison where all you change is the amp?
Who heard something that went against what their theory/experience/expectations told them?
No one really knows exactly what from a technical point of view exactly relates to perception
So I pose the question - who has actually done blind AB testing? Or at least a fair side by side comparison where all you change is the amp?
Who heard something that went against what their theory/experience/expectations told them?
If you can get over the fan noise, a pro amp can be very hi-fi. Crown and QSC are large companies that build very sonic amplifiers. They have been in business for years, and their products are used in recording studios, theatres, operah houses etc.
They know that amplifiers are made of transistors, resistors, heatsinks, etc., and not snake oil. They are as capable of putting sound quality in their amp as any of the big hi-fi manufacturers.
They have the numbers to go head to head with so-called hi-fi amps ten times their price. The hi-fi industry is riddled with companies claiming that numbers don't matter, but generally that comes from companies that lack the numbers.
You can bet the hi-fi magazines that get their revenue from hi-fi manufacturer and vendor advertising won't publish an honest double blind review of a pro amp and some hi-fi amp. It would turn the hi-fi snake oil industry as we know it up side down.
They know that amplifiers are made of transistors, resistors, heatsinks, etc., and not snake oil. They are as capable of putting sound quality in their amp as any of the big hi-fi manufacturers.
They have the numbers to go head to head with so-called hi-fi amps ten times their price. The hi-fi industry is riddled with companies claiming that numbers don't matter, but generally that comes from companies that lack the numbers.
You can bet the hi-fi magazines that get their revenue from hi-fi manufacturer and vendor advertising won't publish an honest double blind review of a pro amp and some hi-fi amp. It would turn the hi-fi snake oil industry as we know it up side down.
About the alesis ra-500: look this, seems to be the same component!
http://www.behringer.com/A500/index.cfm?lang=ENG
http://www.behringer.com/A500/index.cfm?lang=ENG
Behringer EP2500
Just wanted to state the following:
I have tested a behringer 2500 pro amp under "home" conditions and compared it to other amps such as Gamut 500 monos, Transcedent T8 tube OTL, velleman k4040, hybrid tube ATC, home made solid state amp two monos 150w pc with 80000uf psw capacitance per channel. The preamp used was a Basie from DIYhifsupply, the speakers were B&W 7NTs
Results
1. the behringer was not good and clearly the worst of all without the pre-amp used .
1. With the preamp used with the behringer the OTL was better on the highs and mids but no comparison on the lows.
2. With the preamp used the home brewed amp was a bit better on the mids and highs but the lows were still better with the behringer
3. The behringer with the preamp used was clearly better than the Gamut monos 500 and the D250, overall.
4. The velleman was OK but the hybrid lagged behind by a huge margin.
5. Overall in terms of balanced sound ie bottom end mids and highs the behringer used with the preamp was the best combination of all.
Conclusion
300US preamp +300 US power amp were much better than a few thousand USD of equipment.
Kit building is more fun, but does cost a lot more in parts & time, having in mind that the toroidal alone used in the behringer costs more to buy alone than the whole amp, not to mention the power transistors, case, heatsinks, caps etc.
My next project would be to tweak the behringer and remove some triac and heat protection on the signal path and increase the PSU capacitance.
I guess if one were a use a better pro amp made by Crown, QSC etc one would really get a lot more out of such a combination.
(the above are strictly my own subjective experiences ie the experiences of a layman with no background nor education in music reproduction and should be taken with a lot of salt!).
Just wanted to state the following:
I have tested a behringer 2500 pro amp under "home" conditions and compared it to other amps such as Gamut 500 monos, Transcedent T8 tube OTL, velleman k4040, hybrid tube ATC, home made solid state amp two monos 150w pc with 80000uf psw capacitance per channel. The preamp used was a Basie from DIYhifsupply, the speakers were B&W 7NTs
Results
1. the behringer was not good and clearly the worst of all without the pre-amp used .
1. With the preamp used with the behringer the OTL was better on the highs and mids but no comparison on the lows.
2. With the preamp used the home brewed amp was a bit better on the mids and highs but the lows were still better with the behringer
3. The behringer with the preamp used was clearly better than the Gamut monos 500 and the D250, overall.
4. The velleman was OK but the hybrid lagged behind by a huge margin.
5. Overall in terms of balanced sound ie bottom end mids and highs the behringer used with the preamp was the best combination of all.
Conclusion
300US preamp +300 US power amp were much better than a few thousand USD of equipment.
Kit building is more fun, but does cost a lot more in parts & time, having in mind that the toroidal alone used in the behringer costs more to buy alone than the whole amp, not to mention the power transistors, case, heatsinks, caps etc.
My next project would be to tweak the behringer and remove some triac and heat protection on the signal path and increase the PSU capacitance.
I guess if one were a use a better pro amp made by Crown, QSC etc one would really get a lot more out of such a combination.
(the above are strictly my own subjective experiences ie the experiences of a layman with no background nor education in music reproduction and should be taken with a lot of salt!).
I have the behringer EP2500 but I use it for my subs. I have run my mains on it just out of curiosity, and it sounded quite decent. I've also used other similar high power PA amps. With one in particular, my parents actually spent more time sitting on the couch just listening to music than ever before. They never do that, so it made me think it certainly can't be that bad if even they are drawn in to the music!
Still my position on amps is that the differences are very subtle and that even cheap amps come far closer to ideal performance than the best speakers you can get.
Having said that, I've noticed subtle differences on amps compared side by side even when I wasn't expecting to hear anything.
Still my position on amps is that the differences are very subtle and that even cheap amps come far closer to ideal performance than the best speakers you can get.
Having said that, I've noticed subtle differences on amps compared side by side even when I wasn't expecting to hear anything.
there is no dount that building an amp using prime parts and topology as many of those offered by decent kit vendors with a good PSU will get you everywhere but my main point is that these Chinese manufactured amps are one hell of a bargain even as they come out of the box and even for hifi.
would one of these pro amps sound better with a pair of speakers than, just having them hooked up to say a newer yamaha or denon reciever? or do you need a good preamp/amp for it to be a noticable difference. That alessis looks nice I was htinking of trying that or the behringer to hook up to my yamaha htr-5760 to my line arrays. thanks
I am not a home cinema type of guy myself so I cannot really compare. I have serious doubts if any home type of dts receiver sold nowadays will even come close to a good pre amp / amp combo.
If you need power (in my opinion everybody does and you wont know till you test it) then the pro amp is a good cost efficient solution towards that objective, but always in combination with a good pre amp.
The best solution would be to buy independent modules and build the amp from scratch, that is if you have the time. It will cost more but the benefits outweigh the costs. If you dont have the time then the pro amp is a good cost efficient way round it.
If you need power (in my opinion everybody does and you wont know till you test it) then the pro amp is a good cost efficient solution towards that objective, but always in combination with a good pre amp.
The best solution would be to buy independent modules and build the amp from scratch, that is if you have the time. It will cost more but the benefits outweigh the costs. If you dont have the time then the pro amp is a good cost efficient way round it.
Re: Behringer EP2500
Dear Sir,
thank you for your very interesting post.
In the end it seems that the power amp has just to do the "heavy work" (i.e. to supply current to the load) and the preamp gives the overall tone to the sound.
This is very interesting.
Needless to say that some of your words could cause an earthquake like:
" 3. The behringer with the preamp used was clearly better than the Gamut monos 500 and the D250, overall."
" 5. Overall in terms of balanced sound ie bottom end mids and highs the behringer used with the preamp was the best combination of all."
expecially taking into account the very high reputation of the Gamut brand in the high-end circles.
Now a question, have you heard the smaller Behringer EP1500?
Someone tried both, I mean the 1500 (class AB) and the 2500 (class H, but I do not know what this means), and found the EP1500 better sounding.
Thank you very much again for your very valuable post.
Kind regards,
beppe
Villaw said:
Dear Sir,
thank you for your very interesting post.
In the end it seems that the power amp has just to do the "heavy work" (i.e. to supply current to the load) and the preamp gives the overall tone to the sound.
This is very interesting.
Needless to say that some of your words could cause an earthquake like:
" 3. The behringer with the preamp used was clearly better than the Gamut monos 500 and the D250, overall."
" 5. Overall in terms of balanced sound ie bottom end mids and highs the behringer used with the preamp was the best combination of all."
expecially taking into account the very high reputation of the Gamut brand in the high-end circles.
Now a question, have you heard the smaller Behringer EP1500?
Someone tried both, I mean the 1500 (class AB) and the 2500 (class H, but I do not know what this means), and found the EP1500 better sounding.
Thank you very much again for your very valuable post.
Kind regards,
beppe
Villaw, I had a look back at your previous post and it was very interesting. I use the Behringer EP2500 for my subs and I think there really is no substitute for brute force (unless you have very efficient bass) and reserve power as bass is very dynamic and demanding.
Your comments highlight one of the advantages of going active - use amps where they perform best. Use the Behringer for bass, then you can use lower powered amps that perform well in the range they cover. Then the get the best of both worlds.
Going active you don't need as much power as well. Here's an example. Suppose you have a 100w amplifier and a 3 way speaker. Depending on xo points, you might have 40% power to the bass, 45% to the mid and 15% to the treble, although in practice you would need more power for the bass.
Now we have instead of a 100w amp, 40w, 45w, 15w. The tweeter could be driven with a low power tube amp if desired.
Allowing for the efficiency improvement since power is not wasted heating up the passive xo, the tweeter could be driven by a lower powered amp, and the mid could probably be 30w.
If you wanted serious output then you could go something like this:
Behringer EP 2500 for the bass 2 x 650w
Behringer RA500 for mid 2 x 230w or something like a Rotel
and a regular hifi 50ish watt amp for the treble
I'm also suspicious of the quality of a lot of AV receivers, but some of them such as NAD have pre outs on no too expensive models so you can add on power amps, but with NAD you can still use those power amps if you want to go active.
Your comments highlight one of the advantages of going active - use amps where they perform best. Use the Behringer for bass, then you can use lower powered amps that perform well in the range they cover. Then the get the best of both worlds.
Going active you don't need as much power as well. Here's an example. Suppose you have a 100w amplifier and a 3 way speaker. Depending on xo points, you might have 40% power to the bass, 45% to the mid and 15% to the treble, although in practice you would need more power for the bass.
Now we have instead of a 100w amp, 40w, 45w, 15w. The tweeter could be driven with a low power tube amp if desired.
Allowing for the efficiency improvement since power is not wasted heating up the passive xo, the tweeter could be driven by a lower powered amp, and the mid could probably be 30w.
If you wanted serious output then you could go something like this:
Behringer EP 2500 for the bass 2 x 650w
Behringer RA500 for mid 2 x 230w or something like a Rotel
and a regular hifi 50ish watt amp for the treble
I'm also suspicious of the quality of a lot of AV receivers, but some of them such as NAD have pre outs on no too expensive models so you can add on power amps, but with NAD you can still use those power amps if you want to go active.
Hi Paulspencer,
I am inclined to believe this
I cannot give clipping levels as the poster has done but I believe the shouting you hear when music is turned up is due to the very high peak voltages that get clipped from short duration events.
To avoid this you need enormous headroom on dynamic signals.
With active amps/speakers you can avoid some of the peak voltage problems by splitting the frequencies to each amp.
However, getting to my main point I think your advice on power splitting is very misleading. I think there is some evidence that peak voltage between bass, mid and treble needs a little tailoring but at most this is likely to be 100%, 100%, 80%. This leading to a power recommendation of 100%, 100%, and a slight reduction to 64% for treble (-2db). Much of the reduced power capability of the treble amp will be made up by the typically more efficient treble drivers that are often 1db to 3db more sensitive than the mid/bass or true mid drivers and even less efficient true bass drivers (not including PA & guitar drivers that roll off at 40 to 50Hz). This results in the same SPL at all frequencies and not the -5db you indicate.
In conclusion, I would recommend the power split for a three way as 50W +50W +30W into drivers of about 88db, 88db, 90db, giving peak SPL of about 105db, 105db, 105db for all the drivers in a typical 3way.
If you choose a 85db bass driver then the bass amp needs to be re-scaled to 100W to match the 105db SPL.
I am inclined to believe this
from thread; Feel the power! 1.5 KW amp.
I cannot give clipping levels as the poster has done but I believe the shouting you hear when music is turned up is due to the very high peak voltages that get clipped from short duration events.
To avoid this you need enormous headroom on dynamic signals.
With active amps/speakers you can avoid some of the peak voltage problems by splitting the frequencies to each amp.
However, getting to my main point I think your advice on power splitting is very misleading. I think there is some evidence that peak voltage between bass, mid and treble needs a little tailoring but at most this is likely to be 100%, 100%, 80%. This leading to a power recommendation of 100%, 100%, and a slight reduction to 64% for treble (-2db). Much of the reduced power capability of the treble amp will be made up by the typically more efficient treble drivers that are often 1db to 3db more sensitive than the mid/bass or true mid drivers and even less efficient true bass drivers (not including PA & guitar drivers that roll off at 40 to 50Hz). This results in the same SPL at all frequencies and not the -5db you indicate.
In conclusion, I would recommend the power split for a three way as 50W +50W +30W into drivers of about 88db, 88db, 90db, giving peak SPL of about 105db, 105db, 105db for all the drivers in a typical 3way.
If you choose a 85db bass driver then the bass amp needs to be re-scaled to 100W to match the 105db SPL.
Very interesting quote.
I'm not giving advice, I'm making a rough example. If you go from a passive speaker driven by an amp, you don't need 3 amps of the same power to get the same result in terms of SPL. You should get there with less total. The percentages are based on a guess at typical xo points and based on an article by Elliot Sound Products which seems to make sense.
My point is not to debate the finer points of going active as this isn't the thread for that, but instead to point out that it's worth considering going active, and that it might even be more cost effective than some of the alternatives.
But, of course different views is what it's all about here.
I'm not giving advice, I'm making a rough example. If you go from a passive speaker driven by an amp, you don't need 3 amps of the same power to get the same result in terms of SPL. You should get there with less total. The percentages are based on a guess at typical xo points and based on an article by Elliot Sound Products which seems to make sense.
My point is not to debate the finer points of going active as this isn't the thread for that, but instead to point out that it's worth considering going active, and that it might even be more cost effective than some of the alternatives.
But, of course different views is what it's all about here.
paulspencer said:
Hello Paul
A while pack I participated in an "amp off" where we compared denon, crest, adcom and souncraftsmen amps driven full range and in the bass of a biamplified system.
Expectations were that the adcom would probably sound the best (being a "high end" amp) and the crest probably would hit the hardest, and the denon would sound pretty good as well.
To our surprise the denon couldn't handle the test and would shut down almost immediatly - it was out of it's league driving hard bass.
The adcom ran extremely hot on one side of the chassis, we were worried that it might be close to failing and didn't push it. It didn't sound good at all.
The real surprise was that in a slugfest the soundcraftsmen clearly out powered the crest in both bass and dynamics. The crest running out of steam and sounding harsh and strained near it's limits.
The souncraftsmen won. It sounded the best, didn't shut down, and actually remained cool throughout the test. You would think it was a preamp from it's case temp.
anyway, just my $.002.
K-amps said:
Mcintosh autoformer amps can drive very low (0.5 ohm) impedance's safely.
http://mcintoshlaboratory.tripod.com/aa/mc2300.htm
The greatful dead used the mc2300 in there "wall of sound" I believe.
http://en.wikipedia.org/wiki/Greatful_dead#Wall_of_Sound
The SAE 2401 could drive very low impedances according to stereo reviews test (900 watts into low impedance). SAE was used professionally at that time. while being rated at only 250 into 8 ohms.
http://www.jims-sae-site.com/01_brochure/2401d.jpg
The souncraftsmen A5001 had an "auto buffer" circuit that allowed it to drive low impedance loads safely. We verified this by hooking up 3 boston acoustics passive subs in parallel to one chanel and it handled it no problem.
http://www.hifi-museum.com/images/pa/sc_test1_p3.jpg
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