Since it overlaps what is selected in the crossover frequency selector, I always left it OFF.
They are all analog circuits in the SPA250, there is nothing that works in the digital field. Then they released the SPA250 with DSP, possibly in that case it did.
MiniDSP is ok, it's a powerfull dsp for it's size/price but it's weak point is the ad/da convertors. Rew is a very powerfull tool i use for measuring, but i never used it with the MiniDSP. But i prefer mostly to use total different systems than you (analog passive crossovers and class A or AB amps).
Crown XLS is a very good class D pro audio amp i would more use in fixed bar installations, not at home, but many do and there are mods to replace the fan, that is a bit noisy if you're picky. And the Behringer amps (at least the latest generations) are ok, as long as you don't push them against their limits (count half the advertised power) and do some minor mods (mainly installing low noise cooling fans and heatsinks).
But real good class D amps are those from Hypex and Icepower. They are modules at the base, that can be build into somthing, altough hypex does sell them in plate amp and kit form also (with build in dsp in the plate amps). I have no personal experience with the plate amps, but i do listen sometimes at the Hypex Ncore 400 kit that a friend build to drive his 3 way system (designed by Troels) and they do sound good, but lack the life i get from class A or AB (tube or solid state). Those Hypex Ncore amps are not cheap altough... And of course you also got Purify amps, but those are even more expensive and still in raw board style (not even kits as far as i know) or in very expensive (non-diy) fancy designed "hi end" amplifiers.
But again, don't expect wonders from changing amps, they are a very small factor in sound when you got a half decent one that can deliver the power your speaker need, speakers are way more important.
Crown XLS is a very good class D pro audio amp i would more use in fixed bar installations, not at home, but many do and there are mods to replace the fan, that is a bit noisy if you're picky. And the Behringer amps (at least the latest generations) are ok, as long as you don't push them against their limits (count half the advertised power) and do some minor mods (mainly installing low noise cooling fans and heatsinks).
But real good class D amps are those from Hypex and Icepower. They are modules at the base, that can be build into somthing, altough hypex does sell them in plate amp and kit form also (with build in dsp in the plate amps). I have no personal experience with the plate amps, but i do listen sometimes at the Hypex Ncore 400 kit that a friend build to drive his 3 way system (designed by Troels) and they do sound good, but lack the life i get from class A or AB (tube or solid state). Those Hypex Ncore amps are not cheap altough... And of course you also got Purify amps, but those are even more expensive and still in raw board style (not even kits as far as i know) or in very expensive (non-diy) fancy designed "hi end" amplifiers.
But again, don't expect wonders from changing amps, they are a very small factor in sound when you got a half decent one that can deliver the power your speaker need, speakers are way more important.
I can't understand what SQ is, too much use of abbreviations sometimes causes a blackout.
If you have two plate amps, you will not notice much change, 250 watts RMS for each subwoofer is a significant power. Although it is always better to have good reserves for those difficult peaks of music in the low frequencies.
(double bass, organs, etc)
What I don't see as important from my experience is to go from class AB to class D, what's more, I think that a linear PS (power supply) is more reliable in the long term than the switched ones of class D, judging by the amount of PS that I have changed in computers .....
In short, the advantages that I obtained are:
More power reserve - which sometimes results in better sound, will depend on the crossover chosen according to the interaction of the subwoofer with the satellites and the behavior of the room. With DSP, you have more possibilities and precision in the choice of the crossovers, (but only if the amplifier has software to connect via USB to a laptop, with the mechanical local control it is a hell of complicated) and therefore extend the answer to down and play to find the "flatness" of the FR curve.
In my case, I have pending how to extend FR below 20 Hz .....
I have old madisound 10" DVC sub drivers in 60 liter vented boxes that I use as subs crossed over at ~70Hz. Been using them for decades, happily. With various amps. I am currently powering each one with its own TPA3118, a 60W mono chip amp that set me back a coupla bucks each. Sounds fine. Way better than the QSC pro amp I had used b4 that had a noisy fan that couldn't be tamed. I want to mention tho that about 20 years ago I had a PS Audio Delta 100 amp for a few months. Inside it had a large array of 6 or 7 hefty capacitors/channel with power to spare. It was a bit harsh on the high end, which is why I sold it. But hooked up to these same subs it was the most stunning bottom end performance I've ever heard. The whole house shook, literally. They were tight and fast and explosive. Very entertaining. So you never know. That amp was passively cooled btw, no fan.
What is it you never know? Which is better ? and yes, there is not an identical answer for all cases.
In the case of the OP, I think I would go crazy in a few days.
It is very complex to gather so much knowledge and "hit the key" using everything at once:
MiniDSP, Class AB or D board amp, Rew, etc.
I think it totally goes against the premise of the audio:
" Less is more "
Have you seen the Hipex or Bheringer software? You need a crash course in sound engineering to fully understand them.
Yes, the Dayton does not have a fan, it is a bonus.
In the case of the OP, I think I would go crazy in a few days.
It is very complex to gather so much knowledge and "hit the key" using everything at once:
MiniDSP, Class AB or D board amp, Rew, etc.
I think it totally goes against the premise of the audio:
" Less is more "
Have you seen the Hipex or Bheringer software? You need a crash course in sound engineering to fully understand them.
Yes, the Dayton does not have a fan, it is a bonus.
Wow, Sound Quality? That definition belongs to car audio, "thoroughbred" audiophiles do not use it.
Sound Quality, What does it REALLY mean ?? - SQ - SOUND QUALITY - #1 Car Audio Enthusiast Forum in the world! | SMD | Meade916
We do not mix pears with apples ....
The differences between amplifiers tend to be most obvious at the limits.. in the way it handles low impedances, extended high duty cycle operation(sustained synth tones), or how gracefully it clips. Operated within their linear range amplifiers can sound slightly different with fullrange material but it's a lot more difficult to pick out differences at low frequencies, and sounding different doesn't necessarally mean better or worse, just different.
As far as those non defeatable filters go I don't see them having much impact, if you are worried about the phase shift created you have to consider that all the EQ you are applying with the DSP also has a phase shift penalty.
One other thing I wanted to revisit concerning the miniDSP, you said you are only using it on the subs but could it be connected in your system so all the speakers go through it? One benefit of doing this is if there is any latency imparted by the DSP it will be on all outputs so this might actually improve alignment even if you don't add any processing to the tops.
Aside from the miniDSP 2x4 (with outboard linear power supply), I own a Marchand XM44 electronic crossover, a Marchand XM46 passive line-level crossover and several FMod inline crossovers. I've also experimented with a single high quality cap on the power amp inputs to roll of the main speakers. Anything between the preamp and and the main amps gives some benefit, but also compromises the the sound in some ways. My preference so far is to keep the sound of the monitors as clean as possible and supplement with the subs.
My speakers are Bamberg Audio S5-MTM sealed standmounts, each containing a pair of SEAS Excel 6.5" magnesium drivers. They are not stressed running at the highest levels I use, so the level gains from filtering the lows are not a worthwhile compromise.
I must admit I have never experimented with time delay. There's no way I would run the main speakers through the miniDSP 2x4, it is most definitely not good enough. I came very close to buying one of their SHD models. The Studio version is a temptation, but still a risk given my previous experiences. Time delay of the miniDSP 2x4 is specified as only 2ms, not sure about the plate amps. Is time alignment really that significant? Seems to be dismissed as unimportant by some.
Last edited:
Class D has better damping on subwoofers than AB, and the fans are as you thought to my knowledge. I've been told the XLS sound better than the XLi, and you get the included xovers and such with the XLS the XLi does not have.
Yes, I feel the headroom would be a welcome addition to your subs.
Wolf
You won't know until you try it and it won't cost you anything to try.
An analog amplifier has no latency but all digital devices have some.
Some consider it to be more significant than a perfect frequency response. If your speakers are physically aligned in the same plane with subs directly below the tops then any time misalignment is going to be quite small, but if they are elsewhere in the room then the misalignment can be significant and very audible.
Last edited:
The time delay is not the same for all frequencies, it depends on the physical characteristics of the room and the absorption of the materials in it. (furniture) I have experimented and didn't really notice a difference between 0 and - 10 Milliseconds. So I forgot about it and started enjoying the music.
Here an interesting link.
Audibility of group delay at low frequencies – Audio
It actually is if you are very picky, as it causes phase issues. But getting it 100% right is almost impossible, and many speakers that sound good don't take it in account. So it's not the most important factor.
And on bass, it's much less an issue than higher up. But if you are going for perfection, you need to take it in account and try to get as close as you can to this utopic factor of 0,00ms time delay.
And that is one of the biggest advantages of fullrange drivers, they are time and phase aligned and therefor sound more coherent than multiways (which have other advantages).
And in the audio industry they say the tresshold for hearing it is 5ms, so everybody tries to stay below that (also for dac and other digital systems that causes time delays).
And on bass, it's much less an issue than higher up. But if you are going for perfection, you need to take it in account and try to get as close as you can to this utopic factor of 0,00ms time delay.
And that is one of the biggest advantages of fullrange drivers, they are time and phase aligned and therefor sound more coherent than multiways (which have other advantages).
And in the audio industry they say the tresshold for hearing it is 5ms, so everybody tries to stay below that (also for dac and other digital systems that causes time delays).
The link was interesting. I didn't find a significant difference between the low latency and high latency samples through my headphones, but a 5s sample doesn't allow much scrutiny.
Measurement at different frequencies may explain why I've seen both 1mS and 2mS delay stated for the miniDSP.
Phase issues show up in FR measurements, so I'm not concerned because I have a very good FR at the listening seat.
Good to know. I expect I am within that threshold given the sub placement and miniDSP delay, so I'm not going to worry about time delay any further.
From my experience, they don't always show on the frequency response, only the big ones does. The smaller ones that smear the sound are not easy to spot on a frequency spectrum, and they are often only visible when you really measure them.
First i also did not took much attention to it, but when i started to do it, my speakers started to sound a lot better with the same drivers in the same box with more or less the same crossover frequency and slopes. But i'm rather picky on the crossovers, the often necesairy evil... That's why i still prefer fullrange drivers, or at least a waw setup where the crossover is very low. You may be not that picky.
If you are a reader of Troel´s, you will have read that unfortunately an extended range speaker (FR, gg, I do not want to contradict myself with the above
) cannot be extended at the ends of the audible band. We have all experienced it. would be these "other advantages " of a multiway? ( I add disadvantages here too ) , phase shifts? I cannot imagine others that are more important to compensate for the remarked ...I consider a 3-way limit to be acceptable, the more there are, the more problems arise in the design of a passive xover, but prestigious brands with a lot of research behind them already achieved excellent results before the advent of computer programs.
Take, for example, a JBL 250 TI.
Is it possible that any electronic beginner can achieve the same results? Hmm, I don't think so, experience and knowledge don't come in a delivery on demand. Right here in the forum there is a recent thread from someone asking for help designing a simple two-way .....
JBL 250Ti loudspeaker | Stereophile.com
Attachments
Last edited:
If you are a reader of Troel´s, you will have read that unfortunately an extended range speaker (FR, gg, I do not want to contradict myself with the above
Well, that is an opinion, many experience different. I did sell most of my multiway systems for a fullrange MLTL and a 2 way waw system with a fullrange driver and a woofer (see picture) and those do all i need for me. But i use very engineered drivers (Mark Audio) where the shallow cone gives a good dispertion and with enough xmax to give real bass. My MLTL (the black one) goes from 20kHz to 32Hz flat within 10dB with a 6" driver, but it does not go very loud (still hits 100dB, but not more) and is not perfectly flat in response (which is the compromise).
But if you're after a perfect flat response and a very controlled dispertion or want high volume, it's much easier to do it with a multiway. But all systems are compromises, and it's a personal choice which factors are more important for you. So if you prefer multi way, buy/make those.
And Troels is a very good designer, but no the almighty know-it-all in speaker building. His philosphy is also based on his preferences, which are subjective. I do read his stuff and learn a lot from it, just like i also learn from other people (Toole, Martin King, Linkwitz, ...) but don't take their view as the absolute undisputed truth in audio.
Attachments
I agree with you, I only cited Troels because I like to reread it, (I did a lot when I built his DTQWTII design) as well as Lynn Olson, both seem very didactic to me. The Linkwitz articles (RIP), on the other hand, are more for advanced electronics and acoustics than for amateurs or simple technicians - like me - who stayed in the 70s.
What I don't understand is this phrase´s of yours:
My MLTL (the black one) goes from 20kHz to 32Hz flat within 10dB with a 6 "driver, ....
But if you're after a perfect flat response ...
If there is a variation of 10 Db it is not flat, in addition, there are no "flat" acoustic cabinets from 20 to 20000 hertz, it is a utopia, and it is not even necessary, they can measure with some peaks and valleys and sound good, and others measure with fewer ups and downs and sound bad, unpleasant to the ear.
Stereophile
What I don't understand is this phrase´s of yours:
My MLTL (the black one) goes from 20kHz to 32Hz flat within 10dB with a 6 "driver, ....
But if you're after a perfect flat response ...
If there is a variation of 10 Db it is not flat, in addition, there are no "flat" acoustic cabinets from 20 to 20000 hertz, it is a utopia, and it is not even necessary, they can measure with some peaks and valleys and sound good, and others measure with fewer ups and downs and sound bad, unpleasant to the ear.
Stereophile
Last edited: