What is Floyd Toole saying about extra amplifier power and headroom?

I think he’s referring to the overall truth that getting bass right is complicated. Too many focus on larger and larger speakers with lower -3dB points and bigger amps when the problem is the room and speaker integration with it.

Power in a consumer amp isn’t nearly as important as low output impedance, low noise at 1W and low distortion. You would be amazed at how much bigger a speaker / amp combination sounds in a well treated room.

Now onto your particular speakers... You are going to be limited by the maximum displacement of the 7" diaphragm. Assuming you have dealt with the room well, and it sounds like you might have, your next step would be to add a subwoofer.

I’ve written a couple of articles here which may help you.


https://speakermakersjourney.blogspot.com/2020/01/the-snr-1-room-response-and-roon.html


https://speakermakersjourney.blogspot.com/2020/04/how-to-not-buy-subwoofer.html

While I’m very pleased with the SNR-1 in room response, the truth is that the 7" woofer will limit the maximum volume before compression occurs. I’ve been to the Magico demo room and hears the S1 Mk II where they also do an impressive non-sub demo, but physics are real. For music, you can get impressive bass out of 7" (as I write), but it will always be limited by the physics of the maximum travel of the driver. In this demo, Alon used "merely" 150 watt amps. :)

https://www.6moons.com/audioreviews/magico/mini_2.html

When I want rock-concert levels, a subwoofer is my best choice, and what I use when watching action flicks. :)

More power and headroom alone may help get bass right especially at high SPLs by avoiding clipping, but alone is most likely not a complete solution in most cases.

Current delivery and related damping factor of an amp also contributes. How much will vary but more difficult load speakers generally benefit from more current delivery capability to control the bass better, meaning a beefier amp than one perhaps of similar power but less current delivery capability. Power and current are not the same thing.

For example Magnepans are not very efficient and benefit from more power but not nearly as much from more current than many dynamic models. Smaller dynamic designs with more extended bass tend to be the least efficient and to also present a more challenging load, so more power and current is typically the key there.

OF course then room acoustics are a big factor for bass frequency response and all that goes with that as well, but that has nothing to do with the gear itself. Once you have an idea of approximately where the speakers will be located, its much easier to get the gear matching right first, then deal with the much harder room acoustics after. Having flexibility in final speaker location is a big help when it comes to bass and room acoustics in general.

Thanks @erik_squires, IMO, all speakers, even floorstanders, could use a subwoofer and I have one in my system, a JL Audio Fathom 110. It has a 900w class D amp and auto room correction. I have the LP freq. on the subwoofer set to 38hz; the Minis go down to 37hz. With the room correction and the LP freq where it is, I feel like I have the sub and satellites integrated pretty well, at least to my ears. I’m using a single sub because I don’t think the room can handle a second one, and after reading Toole, it seems like I have the recommended placement just about right.

Edit: Here's my room:
https://systems.audiogon.com/systems/9016

What do you think the effect would be of adding extra headroom? Or should I be looking more at low noise and low distortion?

Thanks for the links. I’ll read them now.

@mapman very interesting. So what would I do to increase current delivery? I've done a fair amount to treat the room and I feel like my sub is already pretty well integrated. Here's my room:

https://systems.audiogon.com/systems/9016
 

Hi OP:

Yep, this will integrate well, but leaving the mini's to go down to 40 Hz won't really improve your dynamic range.

Lift up the crossover frequency to 80 Hz.

So a couple of things.  If you don't have a high pass filter on your main amp, the speaker and amp will be forced to reproduce the lower octaves, even though you won't hear it.

Not only does this limit dynamic range, but it increases distortion heard from your mains, both harmonic and Doppler.

If you keep your mains at low volumes, this is not a problem, but if your goal is to use the sub to increase bass AND dynamic range, the high pass filter is a must.

If you're talking Floyd Toole, then expect to hear about a Distributed Bass Array too... but since that is off topic that's all I'm going to say about it.


But that isn't what the problem is with excess power. In a traditional push-pull solid state or tube amplifier, distortion decreases as you decrease power, to a point that is about 3-7% of total power, at which point the distortion goes back up. Below this point you are getting excess noise and distortion if your amplifier power is too high for your application, since most of the time you are only using a tiny amount of total amplifier power.


A different problem you've referred to is compression at high volume. This is a common complaint with lower efficiency loudspeakers, known as 'thermal compression'. Essentially the voice coils heat up in time with powerful bass notes and the like; this prevents the speaker diaphragm  from moving as far as it should. The only way to avoid this if you want the sound pressure is to go with a more efficient speaker, with which there will be less thermal compression.

@erik_squires I've considered an active crossover to accomplish what you suggest. My local shop didn't think it would have much of an impact but I'm still curious. I feel like there should be as little overlap of frequencies produced by both the sub and the mains as possible. It sounds like this is what you're saying too. I was considering this device:

https://www.jlaudio.com/products/cr-1-home-audio-subwoofer-crossovers-96020

Other commenters who know the Minis well have suggested getting all the bass out of them as they can produce, which is why I have the LP freq set to 38hz. I've played around with it in a few different places and it sounds good the way it is now. I listen to the Wood album by Brian Bromberg and can hear right down to the texture of the strings on his 300-year-old double bass. It sounds incredible. 

@atmasphere , I just finished the section in the book on bass arrays and my room dimensions don't fit the use case that Toole recommends it for. My room is very irregularly shaped and small, so I wouldn't be able to arrange the subs the way he suggests. In addition, the frequency response he shows for my current sub configuration shows very flat response for the limited frequency range I'm using it for, which is basically 27hz (the lower limit of the sub) to 38hz (where I have the LP frequency set). It's a narrow range but it really fills out the bottom octave. 

I'm not encouraged by your observation about the low efficiency of my speakers since I have no desire to change that part of the system so I have no choice but to deal with it. Perhaps what @mapman was saying about increasing current flow could help this situation. I'll have to look into it. Thanks for your thoughts! 

Hi OP:

The thing about a sub is that you aren't creating a speaker with sub, you are creating a brand new speaker system, of which the sub will handle the lowest octave.

So you are no longer just buying a new component, you are actively involved in speaker crossover design, and it's complicated. Crossovers are not absolute brick walls.  They have slopes and knee points and Q's, or knee sharpness. The idea that you can set your sub to 37 Hz and  your main speakers to 38 Hz is kind of funny. :)

I never said your speaker's were low efficiency.  I said they were going to be bass limited and with enough bass signal will show the original post was concerned with.  That is, they have limited dynamic range, but this range can be improved by limiting the bass the amp/speaker produces.

Do what you will.



Best,

Erik

Using an SPL meter, how loud are you listening when the compression in the soundstage?  Dynamic compression is more likely a problem with your loudspeaker, alterations in soundstage width and depth at high volumes are a problem with your room acoustics.

Diamond,

That’s a function of the amp. I don’t see specs or even better test measurements like Stereophile typically does for your amp into 4 ohms? Generally the beefiest amps capable of driving the toughest loads and delivering current as needed will double power output from 8 to 4 ohms and largely again into 2 ohms. So hard to say exactly where your amp stands in that regard. In general, it is less common for integrated amps to be able to do that but some can. More common with Class D integrated amps than class a/b but the best class a/b integrated amps may still do that quite well.

What atmasphere said about effects of heat on speaker dynamics is certainly true but different speakers address that differently with different levels of effectiveness using technologies like ferrofluid, etc. Ohm is a good example of a speaker that handles power and current very well! I can vouch for that! I would expect the same of the Magicos but can’t say for certain. These are Magico Mini IIs, correct? Though wonderful speakers ( I recall auditioning them well) they are stand mount monitors and were low in the Magico line in their day and could have output level limitations. Not uncommon for many very good monitor speakers.

I have read of claims from Musical Fidelity for that amp to be able to deliver over 100 amps of current which would be very good, but at the same time no measurements or even published specs I can see to verify that. That would be quite exceptional for a Class a/b integrated amp I would say. Too good to be true? Don’t know.

If the speakers are the limitation, adding a separate powered sub and active crossover to limit the low end extension of the Magicos would be a practical thing to try to  offload much of the work from the monitors and make them not have to work so hard.

In my case, just for comparison, I moved from a Musical Fidelity A3CR stereo amp, 120w/ch 8 ohm, 210 into 4ohm spec amp to BEl Canto ref1000m monoblocks, Class D, 500 w/ch 8 ohm, 1000 into 4. The difference in bass control and articulation at all volumes was night and day....simply transformative. This was with both large Ohm 5 and smaller Dynaudio Contour 1.3 mkII monitors, both notorious power and current hungry products.

Class D amps have a reputation in general for vice like bass control, hence their popularity in powered subs.

Toole is right, headroom is useless. Literally. Headroom is by definition more power than you need. Translation: power you will never use. Translation: useless. 

You have made the rookie blunder of buying speakers that are hard to drive. Its not that they are 4 ohm. My Tekton Moabs are 4 ohm too. They are so easy to drive they sound marvelous with my little 50 watt tube amp. They would probably sound pretty darn good driven by my iPod. So (trigger warning!) you can forget impedance.

Buying speakers and amps is so easy. Yet it is not so easy some audiophile can't make it darn near impossible. All you do is eliminate from consideration speakers less than 92dB sensitivity. I know nothing about your speakers, except for having heard the name Magic and knowing that means they are crazy expensive and have a well earned reputation for being hard to drive. So without looking I will guess they are somewhere down in the mid to high 80's. [Fact check: 87dB. Tol ya so!] Which in itself is low enough to all by itself be a problem. 

Sorry, I only kind of glanced at the earlier posts, just enough to know you feel stuck with or married to those speakers. Oh well. Its not current. Its not headroom. Its not tubes or solid state or heat or ferrofluid or any of the other missing the point ideas. Those speakers simply eat power like its going out of style. The answer like I said is remarkably simple. Unless you yourself want to make it darn near impossible. 

Its not "impossible". Like everything it just has to be done right to get the most out of it. The system is only as good as the weakest link. Not just any amp is likely to cut it with the Magicos.

I heard the minis off a very pricey VAC tube amp and a 6 digit system overall at Sound By Singer in a smaller showroom. That combo was top notch, as good as anything, at least at modest volume in a modest size room. The VAC had plenty of juice for the speakers in that room at modest volume. Did not try to go concert level though its not unreasonable to want to be able to do that. I do. But it may well take larger speakers as well to do that. Most monitors can’t, but Magico Mini’s are not most monitors.

Also headroom is not useless. It’s your insurance policy against clipping.

@onhwy61 sorry, I don't have an SPL meter. And I'm not sure I understand the distinction between dynamic compression and soundstage alterations. I'll have to dig around and pay more close attention. Thanks!

@mapman I've never been able to find anything showing the MF power output @ 4ohms but regarding current, the manual says, "current peak-to-peak: 140 Amps."

FWIW, it's a stereo amp (dual mono) and not an integrated one. Knowing that, would that point to the speakers being a limitation? And would an active crossover be the fix for that, something like this:

https://www.jlaudio.com/products/cr-1-home-audio-subwoofer-crossovers-96020

???

BTW, I already have a powered sub (JL Audio Fathom 110). And it seems to integrate with the Minis nicely. 

And the Bel Canto monoblocks are on my list of amps I want to try out. My local hi-fi store is a Bel Canto dealer so I think I can take them for a spin. 

@millercarbon, I never said I felt stuck with or married to my speakers. The Magico Minis sound incredible to my ears. And I paid a fraction of what they cost new. So I have zero regrets. I'm here exploring tweaks to my system. If I wanted to read about your Tekton Moabs, there are 10,000 other posts on this forum where I can find that information. Give it a rest. 

If you can try the Bel Cantos with no obligation that would be worthwhile I think. I am a big fan of Bel Canto and their products are typically highly regarded in reviews. I also have a c5i digital integrated (60 w 8 ohm/120 to 4) in my smaller family room 2 channel a/v system with my smaller Ohms.

Using a crossover to offload work from the monitors and have the sub pick up the slack is a very reasonable thing to try.
Can’t say what will sound best. Only you can tell. But those are both very reasonable and sound things to try.

Sounds like your MF amp can deliver twice the juice to 4 ohms at least for short peaks that require it. That’s not uncommon and still a good thing. How good? Would need some measurements to know and compare.

@mapman thank you! Very helpful! 

Agree with Millercarbon about speaker efficiency. Disagree about headroom. I like having options while listening. High efficiency, low distortion speakers, with crossovers tuned to your taste, plus an amplifier with low distortion and more power than you need, is the beginning of getting it just right for any audiophile.  It’s important to sound good at low levels, medium levels and high levels. 
The perfect system will be able to play distortion free, louder than you ever want to hear it. 

Headroom is for peaks. Without peaks you have compression.
Talk about useless!

Dynamic headroom means having more power than you need.
If you don’t the amp may clip during dynamic peaks.

If I ran the servers where I work without the dynamic headroom needed to handle peak workloads, they would crash and I be out of a job.

Same concept. Dynamic headroom is your insurance against clipping and yes you need more power and often current to get it with less efficient speakers.


More efficient speakers may still present a difficult load and require more current to sound their best so that alone is not a panacea.

Very large speakers are typically more efficient. Some are also easy loads, some less so.

If you want smaller but capable speakers like Magicos, the amp has to be able to up its game to deliver the goods.

Either way or anything in between can work out top notch. You just have to get the system matched and set up well to meet your needs.

@erik_squires thanks for the links. I read both articles and they have me thinking of the one area in my room I haven't treated, the ceiling. The sounds I'm trying to correct is at admittedly very loud levels, so it's possible that it's creating reflections off the ceiling that don't exist at lower levels. After that, I think I need to look at active crossover to control the LP freq. The JL unit I linked above is fairly pricey. I looked at the Schitt unit in your article but it looks like that's more of an EQ than an active crossover. BTW, the reason I have the JL sub's LP freq at 38hz is that I wanted to minimize the overlap between where the mains drop out and the sub picks up as much as possible. The Minis go down to 37hz. Sounds like the active crossover will give me more precise control of the LP freq so maybe it's worth the price, and actually a deal compared to new monoblocks with extra headroom. Am I on the right track? Really appreciate your responses! 

I may have blurred the two above somewhat but just to be clear current delivery is more about tonal quality as well as articulate and detailed bass with difficult loads. Power is more about headroom and clipping with less efficient speakers. Two different kinds of distortion. Most good quality smaller yet bass extended speakers like Magico Mini are necessarily both less efficient and a difficult load.

Hello diamonddupree,

     The Magico Mini IIs are world class performers as far down as they go down in the audible audio spectrum, which is about 40 Hz according to Magico’s published specs. The fact is, these are extremely high quality stand mounted monitors that may be without equal reproducing music within their less than optimum audible technical range capabilities of about 40Hz to 20,000 Hz, even though they likely extend a handful of Hz deeper at a handful of dbs down.
     In my opinion, the "slight compression in the soundstage at higher levels" you notice are most likely the result of your 2-way speakers’ 7" drivers, even though they are very technologically advanced in design and materials, being required to reproduce the midrange frequencies as well as the mid-bass/deeper bass frequencies simultaneously.
     Of course their rated bass extension is only rated at 40 Hz but these 7" drivers are still being sent even deeper bass frequencies to reproduce by your amp. Since your speakers are 2-way and not 3-way, they lack a crossover network that could send the bass frequencies below a given Hz to a separate woofer driver. Therefore, the 7" combination woofer/midrange drivers simply attempt to reproduce both midrange and bass frequencies up to the limit of their capabilities. When you raise the main volume control, this only increases the demands on these drivers to reproduce not only the midrange frequencies at a higher output level, but also the deeper bass frequencies at a higher output level simultaneously. Also more amp current is required to faithfully reproduce bass than midrange frequencies.
     Not surprisingly, these 7" drivers struggle to do both of these things at the same time. The sonic results? The sound quality levels of both the bass and midrange are compromised, especially as the master volume level is increased, and a compression in the overall soundstage is perceived at a minimum.
I seriously doubt an amp with more power, current or headroom is capable of solving the system sq issues you described. I suggest a better solution would be one of the following in order of effectiveness:

1. The addition of a high quality 4-sub distributed bass array (DBA) system, as briefly mentioned earlier by atmasphere, that matches the high quality of your Magico Mini II main speakers, such as the Audio Kinesis Swarm complete bass system reviewed on the link below by the Absolute Sound:
https://www.theabsolutesound.com/articles/audiokinesis-swarm-subwoofer-system/

     I understand you don’t think you have the space in your room to accommodate this, however, according to your room diagram I believe you do. The subs are each only 1’x1’x2’ and would be spread around the perimeter of your room with the drivers facing and only 1-2 inches away from the nearest wall. My main speakers only extend down to 35 Hz and this DBA concept works exceptionally well in my 23’x16’ room. It’s a concept that Floyd Toole, Dr. Earl Geddes and other experts recognize as highly effective because Geddes scientifically proved the concept and published his results in a peer reviewed White Paper, which is available online.

2. The addition of a 2nd sub, either another JL F-110 or even the addition of a larger JL F-112 sub. 2 subs typically perform about twice as well as a single sub in most rooms and the overall bass extension is usually perceived as being as deep as the sub with the deepest bass extension capability. The benefits of using multiple properly positioned and configured subs in a room, that begin to be realized with as few as 2 subs, are bass that is smoother, faster, more detailed, more powerful and dynamic as well as being better blended with the main speakers.  These bass qualities are increasingly more apparent as more subs are added to a given room up to a threshold of 4 subs, after which performance gains from additional subs in the given room typically become smaller and more marginal. 
       As you and others have mentioned, using some sort of active crossover filter device that restricts bass frequencies from being sent to the main amp/speakers, simplifies the setting of low-pass and high-pass crossover frequencies and enables subs to be more easily incorporated, can also result in improved overall system sound quality performance.

Tim

"One of the great challenges of this world: Knowing enough about a subject to think you are right, but not enough about the subject to know you’re wrong" - Neil deGrasse Tyson

@noble100 thank you for that. Makes a ton of sense. I've been very pleased with the tightness of the bass coming from the JL sub and I was considering a second one a while back. I think, based on your comments and a few others', that my first order of business is an active crossover to stop the Minis from going below 80hz and letting the JL sub handle those frequencies. I really appreciate your response. 

Hello,
Typically an amp will increase wattage when driving lower ohm loads. A 100w amp might go to 160w at half the ohms.  It doesn’t always double, but it usually increases. I don’t think power is an issue unless you hear clipping at higher levels. The rock wool could be a little too much if It is really thick. You are drowning out the mids and highs. And the drapery could be too little. Especially if it is not symmetrical. Room treatment is an art. You could be absorbing too much of the highs and those treatments you talked about do very little for bass. Plus the left side should match the right. You might want to switch or add defusers so you don’t kill your highs. At low levels your 7” drivers are balanced or barely keeping up. When you turn up the volume they could be drowning out your mids and highs. I think you need to test with near field listening. If your speaker wires are short get some cheep longer higher gauge wire and put those speakers in a 6’ - 7’ triangle to you. Remove some of the sound of the room. If it sounds really good it’s not your amp or the speakers. It’s the room. Redo the room treatment. Last but not least. Get two subs. My speakers are rated to 25hz. I still have two REL 9t subs. MC has four in his room and he has monster Tekton Moabs. Subs balance out a system and make it seam like your system is a 1000 times bigger even at the lowest volumes. Like I said your 7” drivers might not be moving much at low volumes but a sub can. When you rock out the sub can take over every thing below 50-80 hz. To do: Near field listening to determine is your equipment matched, balance absorption by removing or less thick rock wool to balance curtains, diffusers instead of absorption in some areas. (GIK.com), last but definitely not least a sub or two (sealed and 10” driver/s) stay away from ported subs- too sloppy in most cases. 

The combination sounds excellent to my ears at low to moderate listening levels, but I notice a slight compression in the soundstage at higher levels.

That's what the OP originally wrote.  I understand that to mean the soundstage dimensions shrink at high volumes.  Is that an accurate understanding?  If you have a smart cell phone, download an SPL meter app and take a measurement of the volume level you start to hear this "slight compression in the soundstage".

As mentioned above, the compression you hear is more likely to come from the 7 drivers rather than the amp. The obvious way to find out is by trying a higher spec’d amp on your speakers -- if the compression is gone, go for a more powerful amp.
That should be your first stop.If it’s the drivers, you need to hi-pass the signal going to the magicos, either at ¬60 -¬80H (half or a whole octave above the speakers’ -6dB point). In other words, limit the amount of bass the magicos have to produce thereby reducing the strain on the woofers, and channel those frequencies to your sub.
Any active Xover can do the job, including the one you mentioned.


But it’s strange the drivers overload so fast -- you must be listening very loud :)

diamonddupree , before you spend $3000 on an active crossover to experiment with sub integration, buy a $149 Schiit Loki Mini tone control. It’s a relatively cheap way to experiment with reducing the driver load on your Magico Mini II speakers. You may find that you just need to roll off the lowest frequencies using the Loki and raise the roll off frequency on your JL Audio sub. You did mention that the Magico Mini’s have great bass extension (for stand-mounts) but if it’s at the expense of the rest of the music the point is somewhat moot.

The attenuation of the bass frequenciy range provided by the Loki may not be an ideal match for your speaker/sub pairing in your room but it will at least give you an idea of how the two interact. You might find that having the Fathom 110 provide more of the range of bass frequencies is a good thing. And may help in deciding on whether or not to purchase an expensive crossover unit like the CR-1..
For reference, I have stand-mount speakers similar to mapman and use two 10" sealed powered subwoofers in a 12’x20’ room. The subs are located at two different positions relative to the speakers. I have the Loki Mini tone control in-line between my preamp and a class D amp using one set of pre-outs and the subs are connected to the second set of pre-outs. I ended up rolling off the bass frequencies to the speakers by about 7dB and actually raising the roll off frequency on the subs to 90-100 Hz. Here’s a graph of the Loki’s tone control frequecies: https://i.imgur.com/XGDm140.png.
Just a suggestion for an inexpensive way to experiment with your setup, not necessarily a final solution.
Tom

@tketcham that looks great. This is definitely the way. I was also just looking at a MiniDSP unit. Is that the same as the Loki? It looks like an active crossover that controls roll off frequencies for anything connected to it. It's also super inexpensive. Thanks! 

@gregm I'm going to look at hi passing the Minis with an active crossover, perhaps the Loki that @tketcham is recommending or a Mini DSP. Both look like inexpensive ways to figure out what's happening. And to answer your question, yes, this is only at very high listening levels. My neighbors love me. 

@onhwy61 I'll try an app to test SPL. Wasn't aware of one so thanks! 

OP,

Although I've heard Magico speakers they were not your model.  Much good advice above (save for one comment on headroom).

I really think that you're trying to drive that 7" too hard.  And due to the slopes of the crossover there is not a "brick wall" at 37hz and 38hz.

I have a tri-amped system using an electronic cross-over spec'd for my system as in cross-over points and slopes.

You need to take the low bass load off the amp, which will take it off the speaker as well.  I think you might try a cross-over at 100hz give or take.
Go here and check out all the possiblilties:
www.marchandelec.com/electronic-crossovers.html
Phil Marchand can be a big help.
BTW, I have the XM-44 (It is tunable with different circuit cards).

Regards,
barts

Perhaps what @mapman was saying about increasing current flow could help this situation. I'll have to look into it. Thanks for your thoughts!

The thing is, when you have thermal compression there is a tendency to turn up the volume/throw more power at it (if there is increased current then there is increased power) but that does not help if there is thermal compression - in fact it makes it worse. But if you are planning to get some of the bass energy off of the woofer, then it will have less thermal compression. So Erik's suggestion should be looked into, as well as a Distributed Bass Array, since the shape of the room really isn't relevant (I'd talk to Duke at Audiokinesis about that since he is really one of the few selling a DBA-dedicated sub system). 

A DBA has its own benefits regarding good bass throughout the room but only 1 sub is needed to offload work and reduce risk of compression initially although a DBA might introduce some unique connection requirements that would have to be addressed sooner or later so best to consider that up front.

DBAs add complexity and would also likely take more time and effort to get right initially as a result. If it were me I would solve one problem at a time....resolve the problem at hand first with existing sub then consider adding DBA after that is resolved, but only if worth it for you.

OR try those Bel Canto Class D amps as well if you can with no financial risk. That would keep things simplest and might make a big difference. How much will depend on the Magico’s ability to go loud without significant compression and how well the current amps truly can stand up. Other Magico mini owners would probably be best ones to provide information on how well they go loud and dynamic. Compression is real but may or may not be a significant issue case by case. Smaller speakers certainly up the risk. Sometimes you never know until you try. It’s nice to only have to add subs to extend the bass, not as part of a solution to fix it. Unless you are a "bass hound", I would expect the Minis driven to their max to be all the speaker most would need in most rooms, at least if room is not too large.

If it were me that owned the Magico Mini’s like any very good speaker, I would do anything I could ie throw the kitchen sink at it as needed to allow it to perform at its best before adding anything else.

That’s what I did with my big Ohm 5s and it payed off 100%. No subs!!

I never felt a need to add a sub even with the Dynaudio Contour monitors, though for some more extended recordings it would certainly have helped.

I do use a sub with my kef ls50s. Those are the smallest monitors I have run regularly but wonderful within their limits and with a sub they are top notch, up to a certain SPL level that is more than satisfactory in the small room they are in. THe kefs + sub cannot compete with the much larger Ohm 5s in a much larger room with no sub in terms of going loud and clear.

The Ohm 5’s with the 500 w/ch Class D Bel Cantos are the bomb. You turn up the volume and they keep going louder and clear until you reach those very high SPL levels that eventually get uncomfortable and can even cause damage to to the ear no matter what. THing is you never realize how loud the things are actually playing until you try to talk to someone and hear. That’s always a good sign from a distortion perspective! I know Ralph would agree with that. Compression is not an issue.

My goal was to be able to do that. It took the 500 w/ch Class D BEl Cantos to do that. The previous 120 w/ch Musical Fidelity was no match. Nor the 330 w/ch Carver amp prior to that (voiced like a tube amp, limited current delivery into 4 ohms). The Carver did very well with the Magnepans I had prior to the big Ohms though.

Magico Minis.....those are very good standmount speakers.....larger than many if not most.   I would not expect them to compete with larger speakers of similar quality in terms of ability to go loud, but would expect them to be more than capable alone in a small to modest sized room driven to their max.  Again, would be nice if other Magico mini owners would chirp in with their actual experiences trying to crank up the minis.

@barts thanks, lots of customization with that unit. Are you familiar with the MiniDSP? Any thoughts on how they compare? Much appreciated. 

@mapman I'm going to try rolling off the Minis closer to 80hz or thereabouts with an active crossover and see what that does before I get a second JL sub, which I may do at some point down the road. I also want to demo the Bel Cantos from my local dealer and possibly some Simaudio monoblocks. I'm still not sold on Class D for mains but willing to give them a shot. Thanks for your responses! 

Hi OP:

The Loki was offered as a tone control, in case you just want more bass as an alternative to buying a subwoofer.

Yes, the ceiling can be part of the issue. At louder volumes reflections and the resonance time matters a lot more.

miniDSP is an active crossover with EQ capabilities. Some JL Audio subs include automatic integration/crossovers and so I highly recommend them as they include all the expert knowledge in configuring your mains and subs, plus I like the results.

I know what you were trying to do, but without measurements it’s hard to tell what the right HP or LP setting is correct. Often crossover filters are offset to match both in phase and amplitude. Your speaker doesn’t go down to 38 Hz. it has a -3 dB response at 38 Hz (usually how this is spec'd, some use -6 dB), below which it drops around 12 dB/octave. So something like this:

-3 dB @ 38 Hz
-15 db @ 18 Hz


However this is the anechoic response. Who knows what it’s doing in your room without measurement? :)

One quick test I forgot to mention was the 2' test.

Sit in front of your speakers, around 2-3' and listen when you hear the problem.  Is the problem still there close up?

If yes - The problem is your room.

If no - The problem is the speaker or before.


Best,

Erik

The Minis go down to 37hz. Sounds like the active crossover will give me more precise control of the LP freq so maybe it's worth the price, and actually a deal compared to new monoblocks with extra headroom. Am I on the right track? Really appreciate your responses!

Absolutely.  Not only that, once you are into this, you can add EQ to the bass to tame room modes. :)

Best,

Erik

Sounds like a plan.  I am very interested to hear how much different or not  the BCs sound from your current amps and how that pans out for you.

I'll go out on a limb based on my prior MF->BC Class D change which is similar but different and say the difference will be clear and noticeable, FBOFW. 

@mapman based on what you were saying before about current delivery, with the BC's Peak Output Current @ 45A, wouldn't that be a little too low for the Minis? And much lower than the MF @ 140A? 

Well its 45 amps per monoblock X 2 = 90 amps total.....nothing to sneeze at especially with a most efficient Class D design.

Musical Fidelity is a stereo amp so most likely the peak is 140A total.

Again, specs never tell all the story, but in lieu of similar measured specs into 4 ohms, 140 amps peak alone is more grey. It’s not uncommon for amps to cite high peak current delivery but without measurements or specs indicating what that means into 4 and even 2 ohms, its harder to make a valid comparison. Not to mention one being very efficient Class D and the other less so Class a/b.

Measurements from an independent source is best. Bel Canto amps regularly get the full review and measurement treatment from Stereophile to add clarity.

Meanwhile every Class D amp I have heard matched properly to pre-amp delivers a vice like grip on the bass that might sound relatively lean to some. WHen I first turned on my ref1000ms, I thought the bass was totally gone. No exaggeration. THen once my ears adjusted I heard it all.....extended, detailed controlled and articulate, not as fat flabby and one note as before.

Meanwhile newer BEl Canto Class D amps claim stability into 3 if not two ohms. That’s pretty good! DO Minis imdepance go lower than 3-4 ohms at any frequency? How about phase? DOn’t know offhand but that would tell even more about how difficult a load they might be or not.

Hello diamonddupree,

     After my last post, I think you received some good advice from several members on the benefits of multiple subs and active crossover devices.  I  run my mains full range and have my 4 subs low passed between 40-50 Hz.  I don't utilize an active crossover because I didn't notice a significant sq improvement when I tried one and reduced the bass sent to them.  I believe this was because my class D monoblock amps provide ample power, 1,200 watts each into my 4 ohm main speakers, and ample current, up to about 30 amps.
     I just wanted to let you know, however, that I believe you may perceive a significant improvement in sq in your system  by using an active crossover device like the Shiit Loki or DSP Mini to reduce the bass duties of your Magico Mini IIs.   I believe both these devices operate in a very similar manner but I'm not absolutely certain.  
      I also wanted to make sure you understand that utilizing at least a pair of good quality subs are also crucial for providing the high quality bass that will no longer be provided by the combination of your Magicos and your current single sub. 
     It's useful to think of the use of the active crossover device and dual subs as 2 sides of the same coin; they're both partially responsible for seamlessly integrating the high quality bass performance of dual subs with the high quality midrange and treble performance of your Magico Mini IIs.  
     They go together like hand and glove, Mutt and Jeff,  eric_squires and millercarbon as well as Trump and incompetence.

     If you decide to take this path as an upgrade solution, I'll share some more useful info and tips, that may be useful to you, along the way.

Tim  

@mapman according to Valin, "the MAGICO Mini is a textbook-perfect load (never dipping below 4 ohms and staying about 6 ohms for most of its frequency range)."

@noble100 good stuff and much appreciated. I just ordered a MiniDSP HD and should have it in a few days. I'll see how that works out and go from there. Thanks! 

That’s good, but there is still not much to bank on with the MF amp regarding how it handles even 6 ohms nominal even with dips below that. So that still leaves things open perhaps to a significant extent. 6 ohms nominal may be a harder load than 8 ohms nominal with some dips...it all depends. You would have to try them with an amp known to be stable into 4 ohms which in most cases mean an amp spec’ed and preferably measured for 8 ohms that also doubles power as much as possible into 4. The MF might do that pretty well but there is nothing concrete to bank on that it would so far. If it could, you would think MF would document it and make the amp more appealing for more cases. Also the bass control offered by the very efficient Class D amps could still deliver a big difference alone. OR even a Class a/b with good documented performance into 4 ohms. Could even be Class A but that could get very big bulky and expensive to deliver the watts needed for headroom with less efficient speakers going louder.

On the other note, I have considered a miniDSP for use with my KEF ls50s and Klipsch sw308 sub and liked it very much so very interested in how that works out.

If we weren't such sound anal audio buffs we wouldn't even care about these details.  We'd just say hey we have a good enough system and call it a day.   Off course, no self respecting audio kook would EVER do that right?

@mapman guilty as charged! I'll let you know how the DSP works out. Thanks again!