JM Lab Mini Utopia vs Spectral 913.1

alan0354 said:

Yes,


His "small" room is the same size as my living room!!!


I am also eyeing on the pair of Alto Utopia, but seller wants $6800 and $500 shipping. I might wait for it to sit there for a few months and offer lower price.

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I did have the Focal Spectral 913 in 1995.
And later on I had the Electra 936. Then I bought the Alto Utopia with BE tweeters. Even tho the 6" look the same, they are very different and much better in Alto. It is really a different world. And the same with the Beryllium tweeters. Don't go for the older Utopia without the Beryllium tweeters. Also the old 6" in the older Utopia is not really as good as the one in Alto and newer.
Alto was ended in 2008. And it was altered with better parts several times. And to a better speaker every time. The later model have more base and a warmer sound . In the serial number they had an A in the early models. You should look for if there is an C in that number. That's the latest model. There is also a date and signature inside behind the 11"base..
I bought mine 2 years ago for around 4000$(Norway have very good prices for used speakers)
Good luck with your choice.
PS because of the newer model Scala that in Norway cost around 40.000$ . I will say the Alto is worth a lot more than 6000$ when it comes to what you need to compare it to. It is that good.

alan0354 said:

Thanks for the reply. I lost the bit on the Mini Utopia anyway.


Since you have the 913.1 like mine, what do you think about them? I am looking for something that is better. I was looking at the Diva Utopia for a while also, it has Be tweeter. Do you think it's a step up from the 913.1?


Do you have other suggestions? I just want to let the Alto sit a little bit longer to bargain for better price. It's a lot of money for a used pair.


Thanks

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You need to understand that it's 25 years ago I had the 913. Different setup. Different room.
I did pair it with the Accuphase P-360 Amplifier. It was a very good combination. This 913 was very good on classical music, orchestra and easy music..
I did change it with the Dynaudio Contour 3 something. The Dynaudio sounded warmer with more base and relaxed tweeter.
Back in year 2000 I sold everything I had.
In 2015 I bought the Electra 936. And the audiophile journey started again. New house with a difficult room.
Depending (maybe)on what kind of music you listen to. The 936 might be a lot better. For me I'm pretty sure it is. With same system and room I did change this for the Alto Utopia. And wow, that was so much better.

And for your question about the Diva Utopia. This one is a great step up from 913.1.
But, it is more/very difficult to set up and get a good sound in most normal rooms. Maybe because of the side firing base..
And it demands a very stable amplifier.
Actually the Alto is some easier on the Amplifier. But still demands more from Amplifier than the 913. All depending on how loud you want to play. The Alto also sound great in smaller rooms. Mine is put I close to one corner in the room. With one speaker in the middle of the wall. And one close to the corner. In an L shaped room. Still I am impressed about how good it is.
My Musical Innovation mono-amplifiers are 100watts a/b. And 60watts pure A class.
It is really good and seldom to weak.
I did also have before a Bladelius Ymer Mk 2 amplifier with 300watts 8 ohm and doubles down to 4 and doubles to 2 ohm. 40watt pure class A operation on idle..
That was really good and could play really loud. But Musical Innovation Mi17b mono is better because it has a bigger and better base . And therefore also better on lower volumes...

Point is if you buy a newer speaker from Focal it is going to be better. Better elements and newer better filters.

2fastgt4 said:

You need to understand that it's 25 years ago I had the 913. Different setup. Different room.
I did pair it with the Accuphase P-360 Amplifier. It was a very good combination. This 913 was very good on classical music, orchestra and easy music..
I did change it with the Dynaudio Contour 3 something. The Dynaudio sounded warmer with more base and relaxed tweeter.
Back in year 2000 I sold everything I had.
In 2015 I bought the Electra 936. And the audiophile journey started again. New house with a difficult room.
Depending (maybe)on what kind of music you listen to. The 936 might be a lot better. For me I'm pretty sure it is. With same system and room I did change this for the Alto Utopia. And wow, that was so much better.

And for your question about the Diva Utopia. This one is a great step up from 913.1.
But, it is more/very difficult to set up and get a good sound in most normal rooms. Maybe because of the side firing base..
And it demands a very stable amplifier.
Actually the Alto is some easier on the Amplifier. But still demands more from Amplifier than the 913. All depending on how loud you want to play. The Alto also sound great in smaller rooms. Mine is put I close to one corner in the room. With one speaker in the middle of the wall. And one close to the corner. In an L shaped room. Still I am impressed about how good it is.
My Musical Innovation mono-amplifiers are 100watts a/b. And 60watts pure A class.
It is really good and seldom to weak.
I did also have before a Bladelius Ymer Mk 2 amplifier with 300watts 8 ohm and doubles down to 4 and doubles to 2 ohm. 40watt pure class A operation on idle..
That was really good and could play really loud. But Musical Innovation Mi17b mono is better because it has a bigger and better base . And therefore also better on lower volumes...

Point is if you buy a newer speaker from Focal it is going to be better. Better elements and newer better filters.

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Hi 2fastgt4

What you said is music to my ears. The reason I am looking for better speakers is because I design power amps and it's to the point I need a better pair of speakers. I don't mind speakers that are hard to drive, in fact, I pride my amps has very high damping factor (way over 1000) to conquer those hard to drive speakers with sharp peaks of the impedance.

There was a pair of Mini Utopia for $999, that's why I posted this thread, but the seller pull the listing. But I read they are 8ohm, must not be that hard to drive. Even though it's so cheap, I don't think it will challenge my amps. Sounds like the Diva or Alto is what I need, something a big step above the 913.1 and harder to drive. I need challenging speakers to challenge my design. I cannot keep designing amps using the 913.1.

You don't happen to live in the bayarea? I would love to hear your speakers and love to hear your amp to compare with mine. My amps are not class A, but high bias class AB. I designed with error correction to minimize the crossover distortion of the class AB. But they have the first 10W in class A already. It's the heat and the size of the chassis( the heatsink) that is the limiting factor for me. 60W class A must be a huge amp!!! You need good ventilation running your amp.


Alan

alan0354 said:

Hi 2fastgt4

What you said is music to my ears. The reason I am looking for better speakers is because I design power amps and it's to the point I need a better pair of speakers. I don't mind speakers that are hard to drive, in fact, I pride my amps has very high damping factor (way over 1000) to conquer those hard to drive speakers with sharp peaks of the impedance.

There was a pair of Mini Utopia for $999, that's why I posted this thread, but the seller pull the listing. But I read they are 8ohm, must not be that hard to drive. Even though it's so cheap, I don't think it will challenge my amps. Sounds like the Diva or Alto is what I need, something a big step above the 913.1 and harder to drive. I need challenging speakers to challenge my design. I cannot keep designing amps using the 913.1.

You don't happen to live in the bayarea? I would love to hear your speakers and love to hear your amp to compare with mine. My amps are not class A, but high bias class AB. I designed with error correction to minimize the crossover distortion of the class AB. But they have the first 10W in class A already. It's the heat and the size of the chassis( the heatsink) that is the limiting factor for me. 60W class A must be a huge amp!!! You need good ventilation running your amp.


Alan

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Your amps sound very interesting. "Error correction"and high df - sound like you are using global nfb?
Not always, but most often I prefer no feedback at all with the Focal. Focal is really a revealing speaker. And with the nfb(negative feedback)you can hear "time smearing". But there is an balance there to about how much you use. Special the acoustic instruments sounds more real without it. But maybe this is also about everything else in the amplifier.

Yes, the heat build up could be a problem in high biased amplifier. That's why mine was built as 2 mono-amplifiers. Instead of building one very big and heavy the engineer made it in to separate cabinets. So totally more heatsink and more air in the box. That's also a good thing every time I need to move it around. The Musical Innovation is a one man "basement factory". He makes really very good amplifier for the price .

Most speakers from Focal is 8 ohms on the paper. But they fall to 3 ohm on several frequencies. And the fase is also very difficult.
But totally they are not more difficult than a lot of others speakers that have this challenge.
But people expect them to be very easy because of the 91db 8 ohms on the paper.

I live in Norway. So I guess visiting is not an option.

2fastgt4 said:

Your amps sound very interesting. "Error correction"and high df - sound like you are using global nfb?
Not always, but most often I prefer no feedback at all with the Focal. Focal is really a revealing speaker. And with the nfb(negative feedback)you can hear "time smearing". But there is an balance there to about how much you use. Special the acoustic instruments sounds more real without it. But maybe this is also about everything else in the amplifier.

Yes, the heat build up could be a problem in high biased amplifier. That's why mine was built as 2 mono-amplifiers. Instead of building one very big and heavy the engineer made it in to separate cabinets. So totally more heatsink and more air in the box. That's also a good thing every time I need to move it around. The Musical Innovation is a one man "basement factory". He makes really very good amplifier for the price .

Most speakers from Focal is 8 ohms on the paper. But they fall to 3 ohm on several frequencies. And the fase is also very difficult.
But totally they are not more difficult than a lot of others speakers that have this challenge.
But people expect them to be very easy because of the 91db 8 ohms on the paper.

I live in Norway. So I guess visiting is not an option.

Click to expand...

So far, I use a lot of feedback. The error correction is local to the output stage mainly working on reducing the crossover distortion. I don't rely on global negative feedback to fix the cross over distortion. I have a Nakamichi PA-7 designed by Nelson Pass. It's an improved version of his old Threshold Stasis S300. It doesn't have global negative feedback, I don't like the sound. The sound stage just doesn't come out, it's a little behind the speakers plane. Also, the resolution is not good. Honestly, I don't have a lot of experience with different amp topologies, so I can't really say too much other than I had people done testing and consensus is my amps beat the PA-7 by a mile.

I don't know what is "time smearing", can you explain a little more so I can look out for it?

My amps are literally dual monoblock in one housing. The reason is if I have them in separate chassis, I cannot avoid using a coax connecting from preamp to the power amp. The preamp has to have active electronics to drive the capacitance of the coax. I believe in less is more, I don't even use active preamp, the source ( CD, DVD player etc.) just drive a passive volume pot and straight into the power amp to minimize the electronics in the signal path. So I have no choice but to put the dual monoblock into one chassis so the connection is very short and no buffering circuit is needed.

I feel monoblock is the KEY of good sounding as the two channels don't interfere with each other as they are completely separate. You are doing the right thing. I literally have 4 separate power supplies, two for each side, even the front end and the output section use separate power supply.

I wish I have more chance to compare with other high end amps to learn and improve my design. Comparing with the PA-7 is not enough, but it's hard to do comparing, I am not willing to spend a lot of money to buy amps.

The 913.1 is 4ohm, I thought I read Diva Utopia is 4ohm. But I could be wrong. I am waiting for the Alto Utopia to sit a little while before I make an offer. Hopefully a Diva show up as they are a little cheaper.

Yes, Norway is just a little to far!!!! Too bad.


Alan

I was trying to look up Musical Innovation, I just cannot find anything. I am curious about your amp.



I am very interested in "time smearing" you mentioned. I watched this video

Sounds like it is due to the amp is not fast enough to give the attack. Like in the example on the kick drum and keyboard, the one he described with "time smearing" lack the attack and feels less of the dimension to me. That's what I think is the speed of the attack. Or the sound has more snap for the lack of words.



If that is the case, I don't think I have to worry about my amp. My amp has large signal bandwidth of 350KHz, more than 17 times the highest audible frequency of 20KHz. More importantly, the slew rate is over 33V/uS. I can see on the scope even at 300KHz driving into 4ohm load and 60Wrum, I can still see a nice sine wave with no slew rate limit. I checked on the oscilloscope that the frequency response is absolutely flat to at least 100KHz. (bandwidth is defined when the signal falls off to 0.707 of the original amplitude, not flat to the BW limit).



Sorry I might be talking in different terms to describe, I am an EE, I really don't know the terms of audiophile. Hell, I have to look up "time smearing"!!!


Tell me if that's what you mean.

Here is the data sheet for Diva

Hi
Timesmearing as I was thinking is used as an expression when signal goes through an global nfb.
The signal is sent in a loop for correction. And is therefore different"in time"compared to the original signal.
So the video is correct. The expression can be used in several terms.

The Norwegian brand Musical Innovation is very small and local here in Norway.

Above
One mono-amplifier and preamp
Under
Psu for preamp

Amplifier for my Focal center speaker