I recently bought a 300W+300W from coldamp, intending it for the woofer on a bi-amped open baffle I'm building. I tried out the amp on my passive 3-ways (OB not finished yet) and was really impressed with the sound, so much so that I'm considering going class-D for the full rangers of my OB. My issue is that the woofers can safely handle the power, but my full rangers would be annihilated if I accidentally gave them full whack.
My question is what are people using to protect low power rated speakers from high power amps?
S
My question is what are people using to protect low power rated speakers from high power amps?
S
Hi Matty,
It seems like you have got the Oris Orphean from Bert Doppenberg with dedicated passive filters for the BMS coax. If that is the case, then I would seriously consider NOT using an active filter between the mid and the high section of the coax, but only an active low pass for the bass system. I believe that Bert has put a lot of effort in the passive filters for the BMS coax (for instance making them phase coherent), and I would not mess with them or get rid of them. First, filters for the BMS drivers are difficult to get right (I have tried - unfortunately in vain), and second, since the crossover point between the mid and the high section of the coax is around 6-7,000 Hz, the eventual benefit of dedicated amps for the highs are probably minor.
With regards to amps for the bass:
I have tried 3 different Class D amps: (1) eAR MK II amps from Acoustic Reality using ICE modules; (2) TacT/Lyngdorf 2175, and (3) LcAudio ZapPulse ver. 2.2. All have been used on a large horn rig with 29 Hz straight bass horns each using double 15" pro woofers. Of these amps the Ice powered amps sounded the best - also in the bass. Actually the Ice modules sounded as if they went a whole octave deeper than the Tact/Lyngdorf 2175 even though Lyngdorf suggests using these 2175 amps for bass (in my opinion the TacT/Lyngdorf 2175 amp sounds nice, but is least adequate for bass duty). In short: Ice amps are super - also for bass!
Good luck!
Best regards
Peter
It seems like you have got the Oris Orphean from Bert Doppenberg with dedicated passive filters for the BMS coax. If that is the case, then I would seriously consider NOT using an active filter between the mid and the high section of the coax, but only an active low pass for the bass system. I believe that Bert has put a lot of effort in the passive filters for the BMS coax (for instance making them phase coherent), and I would not mess with them or get rid of them. First, filters for the BMS drivers are difficult to get right (I have tried - unfortunately in vain), and second, since the crossover point between the mid and the high section of the coax is around 6-7,000 Hz, the eventual benefit of dedicated amps for the highs are probably minor.
With regards to amps for the bass:
I have tried 3 different Class D amps: (1) eAR MK II amps from Acoustic Reality using ICE modules; (2) TacT/Lyngdorf 2175, and (3) LcAudio ZapPulse ver. 2.2. All have been used on a large horn rig with 29 Hz straight bass horns each using double 15" pro woofers. Of these amps the Ice powered amps sounded the best - also in the bass. Actually the Ice modules sounded as if they went a whole octave deeper than the Tact/Lyngdorf 2175 even though Lyngdorf suggests using these 2175 amps for bass (in my opinion the TacT/Lyngdorf 2175 amp sounds nice, but is least adequate for bass duty). In short: Ice amps are super - also for bass!
Good luck!
Best regards
Peter
Common sence and my ears. As long as the power is clean and undistorted you should not be afraid of you drivers. They will be able to handle a lot of short term power. Just don't make them distort for a longer period.
Hi Peter,
yes I have the Orpheans with the modified BMS4592nd from Bert, but I did not purchase the passive crossovers from him. I visited him several times and discussed with him, that I plan to completely use active crossovers with a PC based software solution (Thuneau Allocator/Phase Arbitrator) He told me, that he thinks that it is not too difficult to design an active crossover for the bms though he is not a fan of digital solutions.
The crossovers designed by him are quite pricy (at least 679 € VAT excl.), though I'm sure that they are very well designed. Perhabs you are right and I should think about this solution too, instead of looking for a 3-way solution ...
Btw, that leads me to another question. Bert told me, that he doesn't like ClassD or Tripath amplifiers. As far as I remember, among other things, he based this on the fact, that ClassD designs typically have a load dependent frequency response. But after reading lots of pages about different ClassD amplifiers I think I learned, that well designed ClassD amplifiers (e.g. Hypex, ColdAmp) dont't have these problem?
So what's the truth? How can I identify, if a ClassD is well designed at this point? Or isn't it a problem with the latest genaration of amplifiers at all? How about tyical Tripath designs, e.g. Hifimediy T3?
Lots of questions. I know ...
Hi Peter,
yes I have the Orpheans with the modified BMS4592nd from Bert, but I did not purchase the passive crossovers from him. I visited him several times and discussed with him, that I plan to completely use active crossovers with a PC based software solution (Thuneau Allocator/Phase Arbitrator) He told me, that he thinks that it is not too difficult to design an active crossover for the bms though he is not a fan of digital solutions.
The crossovers designed by him are quite pricy (at least 679 € VAT excl.), though I'm sure that they are very well designed. Perhabs you are right and I should think about this solution too, instead of looking for a 3-way solution ...
Btw, that leads me to another question. Bert told me, that he doesn't like ClassD or Tripath amplifiers. As far as I remember, among other things, he based this on the fact, that ClassD designs typically have a load dependent frequency response. But after reading lots of pages about different ClassD amplifiers I think I learned, that well designed ClassD amplifiers (e.g. Hypex, ColdAmp) dont't have these problem?
So what's the truth? How can I identify, if a ClassD is well designed at this point? Or isn't it a problem with the latest genaration of amplifiers at all? How about tyical Tripath designs, e.g. Hifimediy T3?
Lots of questions. I know ...
Hi Matty,
I haven't got the Orhpean's - sorry, I did not make that clear. I used the standard (non-modified) BMS 4592ND for some time on different horns with different passive filters (I bought the drivers just before Bert launched the Orpheans....). But I never manached to get them sound right. There was simply to much sibilance (over pronounced s- and t- sounds on female voices) for my taste and finally I gave up. Whether this was because of the non-modified drivers, or because of the filters, or the horns (or a combination of these factors) - I don't know. I have not heard Bert's Orpheans, but would like to! He is very knowledgable for sure and will be able to exploit their potential better than I.
As long as you use some of the better classD amps, I do not think that will make the biggest difference - the speakers will! I have not heard other classD amps than the ones I mentioned above. If I were to start out all over again with classD amps, then from what I have read, I would probably go for Ice amps for the bass and Hypex for the mid/high section.
Best regards
Peter
highfielddrebel: Any power amp is limited by the input voltage. Check what is the input sensitivity of your coldamp, for example 0.66V, what is the max output of your source (or preamp, or whatever is connected to the input of your coldamp), let say 0.66V also, and the power andling of your speaker, i.e. 30W. Calculate a voltage divider or in other words a fixed attenuator (keep in mind power is proportional to the square of voltage) and implement it at the input of the amplifier. With the value I used as an example, a attenuator with a 22Kohms and 10Kohms in series will ensure that the max output of source would only be 1/3 of the max input of amp, or 1/9 of the max power output of the amp or 33W which is reasonnably close to the specs of the speaker.
Then, you'll be sure that the speakers are never driven outside of their spec'd enveloppe and your amp will always stay in its low THD enveloppe. This is a very simple solution to implement but only safe as long as you don't change the source.
Matty: I wouldn't comment on "what is the best class D/T amp for this very specific application" because I believe that with the quality of the choice we now have this question has no real answer. The only question that can be answered is "what is the amp I personnaly prefer in my application depending on what is my definition of a better sound, what are my speakers and what my room look like". Of course, there is some general rules. For highs and medium personal preferences (or subjective, in your system and room, sound quality) comes first because the very good quality choices with more than enough power are so plenty and cheap that it only comes to personal preferences (and room setup and speaker/amp match). For lows, as long as your XO point is close to 100Hz, all you need is an amp powerfull and fast. Even a cheap 2x100W Sure with just an upgrade of the tank caps for low ESRs would be enough.
Now, my personal choices would be Trends TA10.1 for highs and medium even if they are quite expensive for TA2024 based amps because I have never heard anything DIY or cheaper amps better than this. And I would go for a 2x100W Sure board with the Meanwell PS for the lows because it's really cheap and 10$ of caps would make more than good enough for lows (in fact, good enough for full range).
Now, if some people comments that Arjen's TK2050 are so much better than Trends TA-10.1 for much less money, or the same about Hifimediy T3, or Icepower modules, or whatever, I wouldn't be surprised at all. They is so many very very good and cheap class D/T amps now that none is "better". They are just "better" for someone in his own setup.
So I would suggest you buy the cheap ones and try them, then try to find someone not to far to try the more expensive ones. And do not hesitate to try a cheap high power TK2050 on the tweeter because you may, according to your taste, find it better than an expensive Trends TA2024 that I prefer.
Then, you'll be sure that the speakers are never driven outside of their spec'd enveloppe and your amp will always stay in its low THD enveloppe. This is a very simple solution to implement but only safe as long as you don't change the source.
Matty: I wouldn't comment on "what is the best class D/T amp for this very specific application" because I believe that with the quality of the choice we now have this question has no real answer. The only question that can be answered is "what is the amp I personnaly prefer in my application depending on what is my definition of a better sound, what are my speakers and what my room look like". Of course, there is some general rules. For highs and medium personal preferences (or subjective, in your system and room, sound quality) comes first because the very good quality choices with more than enough power are so plenty and cheap that it only comes to personal preferences (and room setup and speaker/amp match). For lows, as long as your XO point is close to 100Hz, all you need is an amp powerfull and fast. Even a cheap 2x100W Sure with just an upgrade of the tank caps for low ESRs would be enough.
Now, my personal choices would be Trends TA10.1 for highs and medium even if they are quite expensive for TA2024 based amps because I have never heard anything DIY or cheaper amps better than this. And I would go for a 2x100W Sure board with the Meanwell PS for the lows because it's really cheap and 10$ of caps would make more than good enough for lows (in fact, good enough for full range).
Now, if some people comments that Arjen's TK2050 are so much better than Trends TA-10.1 for much less money, or the same about Hifimediy T3, or Icepower modules, or whatever, I wouldn't be surprised at all. They is so many very very good and cheap class D/T amps now that none is "better". They are just "better" for someone in his own setup.
So I would suggest you buy the cheap ones and try them, then try to find someone not to far to try the more expensive ones. And do not hesitate to try a cheap high power TK2050 on the tweeter because you may, according to your taste, find it better than an expensive Trends TA2024 that I prefer.
What I really like is the balanced input of e.g. Hypex and Coldamp, because my soundcard has balanced outputs. For me, this is an argument for these products too. Though it's also possible to connect amps with unbalanced inputs directly to the soundcard, i should better use a converter with an amp with unbalanced inputs. I found some very good modules here: funk-tonstudiotechnik.de. Thomas Funk has a very good reputation in Germany for building components for recording studios, but this modules would cost me as much as a good Tripath amp
When looking at the Hypex product portfolio, I'm wondering if there would be any recognizable difference between UcD180ST, UCD180HG and UcD180HG HxR, if they are only used in the bass (up to 270Hz) ...
@highfieldrebel: Could you perhabs tell us some details about your experiences with the ColdAmp? E.g. comparison with other amps, especially other ClassD?
When looking at the Hypex product portfolio, I'm wondering if there would be any recognizable difference between UcD180ST, UCD180HG and UcD180HG HxR, if they are only used in the bass (up to 270Hz) ...
@highfieldrebel: Could you perhabs tell us some details about your experiences with the ColdAmp? E.g. comparison with other amps, especially other ClassD?
I am currently building a three way (actually a two way plus stereo subs, but where do you draw the line between that and three way - 120hz!?!?) active system.
For a long time I have been drawn to hifimediy because of reputation and price. Recently I have read many good things about connexelectronics smps's to run them, which of course has made me look at their amps too. Trouble is there is a lot of choice!
So this puts me in exactly the same dilemma as you.
I am going to be picking peoples brains on this forum soon so look out for my posts. I have a minidsp 2x8 to do the crossover/pre amp duties and want to have class d/t amps to run each mid, tweet and sub.
From what i can gather: With the quality of the amps on offer these days, you won't go wrong. Your choice should be more about an appropriate gain structure and power requirements for your application.
By reputation 41hz amps seem to be the best, but for me this is way too involved in terms of assembly and testing. Connex and hifimediy represent off the shelf and high quality solutions for relatively little money.
Keep us posted with what you decide, and the results. It will be of great interest to me!
Jai
For a long time I have been drawn to hifimediy because of reputation and price. Recently I have read many good things about connexelectronics smps's to run them, which of course has made me look at their amps too. Trouble is there is a lot of choice!
So this puts me in exactly the same dilemma as you.
I am going to be picking peoples brains on this forum soon so look out for my posts. I have a minidsp 2x8 to do the crossover/pre amp duties and want to have class d/t amps to run each mid, tweet and sub.
From what i can gather: With the quality of the amps on offer these days, you won't go wrong. Your choice should be more about an appropriate gain structure and power requirements for your application.
By reputation 41hz amps seem to be the best, but for me this is way too involved in terms of assembly and testing. Connex and hifimediy represent off the shelf and high quality solutions for relatively little money.
Keep us posted with what you decide, and the results. It will be of great interest to me!
Jai
Which unfortunately gives you the extra and perhaps very attractive option of stacking their MiniAmp on that 2x8 and using that to drive the tweeters. So one other option to consider
Yes, that achieving an appropriate gain structure is an important goal to go for sounds very plausible to me. But what does that mean? If you have a big difference in the sensitivity of the bass and the mid/high section, does that mean, the gain of the amp ideally should have the same difference vice versa?
To bring the gain structure to perfection could be an argument for a proper preamp stage, if the amp isn't capable of adjusting the gain level.
Oh yes, I really would like to try them out, but I have no experience in SMD soldering and so I should better keep my hands off this ...
41Hz really should consider to sell more assembled modules
I have also tryed the abletec. And find it to be a very god amp.
I have not that big experience of klass D but that are the first
klass D amp that i could live with.
mats
Last edited:
I have the MiniDSP full digital setup and there was a BIG improvement in sound with the MiniAMP when I changed the output inductors for the fabled Wurth inductors. Then I removed the output filter altogether and got another step up in performance. You should only do this when you have no passive crossover/filter components, even the Zobel on the MiniAMP board had to be disabled. Read the TI app note on eliminating the class D output filter http://focus.ti.com/general/docs/lit/getliterature.tsp?baseLiteratureNumber=sloa023&track=no
Cheers,
Mike
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.