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

I'm glad you are enjoying the results!!

I apologize I was thinking of the generic/common use of convolution filters with Roon, which most time is a thoughtless exercise.
Those same filters however can be used to make much more discrete changes. 

My bad. :)

PS - When it comes to convolution filters and roon, I go 100% with Toole. I think they are too much, and if you want to go that flat, what is the point of your speaker brand to begin with?

With Roon, I prefer minimal EQ, using parametrics. It maintains the character of my speakers, reduces CPU demand on the Roon server, and does the least harm. Also, prevents over-EQing for 1 spot.

If you are looking into CODA, try the Sanders MagTech.  Made by CODA with built in power supply regulation.  The only other big amps I know of who have any sort of regulation are the Krells.  I'm sure there are others though.

That was going to be one of my suggestions from the start, but I thought you wanted to stay with bigger brands.

Best,

Erik

One thing I’ve noticed in reading his book and even in his posts is that his observations are for multi-seat listening.

Yeah, while I will never have achieved the academic and scientific level of achievement, or renown, of course, that Toole has and deserves, I also come from a motion picture theater background, so I really love his writing and perspective.

In the book, almost everything he has to say about low frequencies and subwoofer placement has to do with optimizing for multiple seating positions. I think this explains a lot about his own choices in home audio. I’m mainly concerned with single-seat listening. My home theater system is good enough for my purposes.

I know it may not sound as relevant, but your fixes are _almost_ always the same. Controlling reverberation time for instance is something hard to do for one spot, without also controlling it in the rest of the room. Adding effective bass traps makes EQ possible.

What Toole gets exactly right, IMHO, is that the concept of room correction is greatly oversold. attempting big corrections in EQ because your sound field sucks doesn’t end up with acceptable solutions for most. Let me explain with a common and specific problem. Let’s say you have a harsh or compressed mid/treble experience in a very live room. Measuring it hyper accurately at your seated position may flatten the curve, but it still won’t sound good. You will control the energy say, between 2kHz and 10 kHz, so it no longer sounds too bright, or too dull, but with long reverb times, all that signal is noise. It’s like watching a movie, where you get the right color and brightness but you can’t tell the actors and scenery apart.

In the bass, with a bad room, the best you can do is clip peaks. Now, that may be a really good improvement, I've seen peaks that were the equivalent of 200x the power output vs. the rest of the system, and clipping them was a major benefit, which EQ can handily do, but trying to EQ these subs into a great response requires a sledgehammer like approach with major amplitude shifts in multiple adjacent bands which, may work for exactly one place and is not all that satisfactory a solution at the end.

Fix your reverberation, and often, the tonal balance fixes itself, and then you are left with very mild, gentle corrections to make. Add bass traps, the peaks flatten themselves, the nulls stop being so severe and again, just a little EQ here and there can give superb experiences.

Hope this helps,

Erik

Hi OP,

Glad you are enjoying your new set up.

I still agree with Toole, in general, that excess amplifier headroom does not seem to have a big benefit, as opposed to having drivers with excess headroom, or reducing the demand on mid-woofers.

The best explanation I have of why subwoofers seem to help speakers perform better in so many ways is not headroom, but Doppler distortion.

It also seems to be why 3-way systems may have a lot more clarity than 2 way systems. 

By removing low frequency demand, you remove a great deal of Doppler distortion you'd have to deal with otherwise. The ability to EQ signals below the Shroeder frequency while you are at it is a big bonus.

Best,

Erik

HI,

So the caps I was suggesting is the same exact idea.

 You'd just have to build your own RCA cable. :) 

You may want to go even cheaper than a miniDSP. :)

Get a capacitor of around 0.04uF and put it in line with your amp inputs.

https://www.partsconnexion.com/JAM-82668.html


BTW, I have a miniDSP and I love it, but I only use it in my sub path way for the reasons you are concerned with.

Of course, if only audiophiles could give up these damn separates and go with an Anthem streamer/preamp or similar with built in room correction and bass management. :)

Best,

Erik

I really like the room correction in the JL Audio, doesn't it have a high pass output as well?  I'd go that route before adding more gear.

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

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

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

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.

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.

I think one area we should talk about is not power, but sag. I don’t have a better word for it, but I’ve seen speakers with low impedance, sometimes deliberately low impedance, sometimes unavoidable, sometimes the result of ad hoc experimentation, become "discerning."  That is, they give off the impression that they are so revealing that different amplifiers now sound glaringly different.

I have come to believe, with limited data that the issue is not the amplifier’s power rating but how consistently it performs across the audio band, and this is a place where the math doesn’t quite live up to the audible effects. I find that speakers with drooping impedance have this characteristic, and that amps which _should_ be quite stiff and sturdy, are still susceptible.

So, I don’t think 300 Watts is a lot better than 200, or maybe 100. It’s the output impedance in the location of the speaker’s impedance droop that matters a lot more. The mythical Krell 50 W Class A which doubles in power down to 1 Ohm is a great example of what I’m talking about. It’s also mroe than I would use, but it helps illustrate what I think is going on.

Yes, big amps tend to have more output transistors, and therefore, lower output impedance, but it’s not the power rating that makes them sound better with some speakers.

Best,

Erik

 I mainly agree with everything erik_squires stated in his last post. My only disagreement is that in my practical experience, the use of 4 subs, properly positioned and configured in a distributed bass array (DBA) concept system, results in exceptionally good bass performance in most any room. Just as Dr. Earl Geddes scientifically proved with his PHD thesis over 4 decades ago.  

Sorry, was assuming 1 sub placement.  I don't have a problem with this either.

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. :)