Jad Freer Sisma Mega Thread.

[Franz975]

Agreed, I would be fascinated to hear the explanation as well.

Jim’s cabinets reinforce my earlier comments about how the perceptions of a cabinet’s performance are mostly based on the designer’s skill and intent. It’s not necessarily related to the magnetic material used. In fact, it’s usually unrelated in practice.

I still don't have any mathematical things to explain here but all the guitar shop I go to explain me that Ceramic have a bigger/more low end compare to a Neodynium magnet.

So I don't know if it is because old speaker designers make the Neo the same way they would make a Ceramic ?

I have heard (and I think Barefaced explain it too but not sure) that to design a speaker you need to know how to make the voicing with the magnet you will use ? Because a Neo and Ceramic magnet doesn't respond the same way and there is a different way of voicing them if I have understand correctly.

But I heard a lot that Ceramic speaker have a bigger punch (or at least old Ceramic speakers cabinet, the heavy ones) compare to the actual light design.
Now I don't know if it is more about the magnet used there or maybe the whole weight of the cabinet ?

The only one I can compare is the Darkglass 210 and an old Mesa Boobie Powerhouse 210.

The Darkglass sound great but has 0 low end compare to the Mesa boogie in my opinion. The Mesa sound really nice I like that cabinet, I wish it add a bit more top end from the woofer because I don't like using the tweeter with distortion in front of it but the darkglass is dark too without it.

I wonder how the JF cabinets sound in comparison to those old Mesa Boogie, Ampeg, etc...

 

[agedhorse]

We have CE but FCC is way to expensive for a small buildier.

I suggest that you read up on the FCC requirements for exporting products with Switchmode power supplies or class D amplifiers into the US. The requirements are not optional like CE is for those who reside inside the EU.

I heard that FCC is 60K or something ?
I don't know a lot about those thing but I remember seeing that about a Bergantino product

It depends on the product(s) and how many times it needs to be retested before it passes.

 

[agedhorse]

I still don't have any mathematical things to explain here but all the guitar shop I go to explain me that Ceramic have a bigger/more low end compare to a Neodynium magnet.

So I don't know if it is because old speaker designers make the Neo the same way they would make a Ceramic ?

I have heard (and I think Barefaced explain it too but not sure) that to design a speaker you need to know how to make the voicing with the magnet you will use ? Because a Neo and Ceramic magnet doesn't respond the same way and there is a different way of voicing them if I have understand correctly.

But I heard a lot that Ceramic speaker have a bigger punch (or at least old Ceramic speakers cabinet, the heavy ones) compare to the actual light design.
Now I don't know if it is more about the magnet used there or maybe the whole weight of the cabinet ?

The only one I can compare is the Darkglass 210 and an old Mesa Boobie Powerhouse 210.

The Darkglass sound great but has 0 low end compare to the Mesa boogie in my opinion. The Mesa sound really nice I like that cabinet, I wish it add a bit more top end from the woofer because I don't like using the tweeter with distortion in front of it but the darkglass is dark too without it.

I wonder how the JF cabinets sound in comparison to those old Mesa Boogie, Ampeg, etc...

You are comparing completely differently voiced cabinets and trying to come to a universal (yet inaccurate) conclusions.

As another point of comparison, virtually all touring pro subwoofers are built using Neo drivers. They have far more low frequency extension than ANY bass cabinet, ceramic or otherwise. It’s not the magnetic material used, in spite of the urban myths perpetuated by marketing folks and those who have no idea what they are talking about.

 

[12bass]

Yeah, seems to be an error in generalization about materials and/or technology rather than looking at the specific implementation. Neodymium magnets don't have a particular "sound"... that's up to the speaker designer, the voicing, efficiency, power handling, etc... they are seeking, and the trade-offs made in service of that goal. Similarly with amp design.

My old Garnet Revolution Bass amp (my first amp, made about 50 years ago) had a pair of 6V6s and a 15" woofer. Neither the amp nor speaker sounded particularly good on their own, nor combined. There was nothing magical in the sound, even though it used tubes and an "old school" 15" driver. It did make an interesting distortion sound when cranked, however... but not much clean volume at all, nor bottom end, nor crisp highs. But I didn't make any generalizations about tubes and 15" drivers from that particular amp.

 

[Franz975]

I suggest that you read up on the FCC requirements for exporting products with Switchmode power supplies or class D amplifiers into the US. The requirements are not optional like CE is for those who reside inside the EU.



It depends on the product(s) and how many times it needs to be retested before it passes.

Nice to know !

So if I buy an amp that doesn't have the FCC I can't go to the US with it ?

 

[Franz975]

You are comparing completely differently voiced cabinets and trying to come to a universal (yet inaccurate) conclusions.

As another point of comparison, virtually all touring pro subwoofers are built using Neo drivers. They have far more low frequency extension than ANY bass cabinet, ceramic or otherwise. It’s not the magnetic material used, in spite of the urban myths perpetuated by marketing folks and those who have no idea what they are talking about.

The older darkglass Ceramic cabinet sounded quite the same to the actual Neo one but with more low end too it is why I though that. Plus that all the guitar shop where I go say that Ceramic sound better and have the low end punch the Neo will never have. So I though it was correct.

I also heard a Mesa 410 with Ceramic and a Mesa 410 with Neo (Traditional Powerhouse and subway serie) and the Powerhouse sounded way better to me than the subway serie which sound quite thin, like there is no balls to the cabinet.

But I know that actual subwoofer mostly use Neo speaker and that work for sure.

 

[agedhorse]

Nice to know !

So if I buy an amp that doesn't have the FCC I can't go to the US with it ?

It may not be legally imported or sold into the US by our federal law.

The older darkglass Ceramic cabinet sounded quite the same to the actual Neo one but with more low end too it is why I though that. Plus that all the guitar shop where I go say that Ceramic sound better and have the low end punch the Neo will never have. So I though it was correct.

I also heard a Mesa 410 with Ceramic and a Mesa 410 with Neo (Traditional Powerhouse and subway serie) and the Powerhouse sounded way better to me than the subway serie which sound quite thin, like there is no balls to the cabinet.

But I know that actual subwoofer mostly use Neo speaker and that work for sure.

Strange conclusions, and I have never heard the comment that the Subway 410 sounds thin, they have more low frequency extension than the Powerhouse Traditional 410, by quite a bit actually.

 

[12bass]

It is important to look at the overall design, the drivers, the cabinet, the cabinet material, tuning, etc... in order to make apples to apples comparisons. Bass reproduction, in particular, involves managing tradeoffs. The general trend in the past decade has been lighter and lighter amps and cabinets. Installed sound systems are less limited by such constraints.

Super deep lows generally require bigger cabinets, which means heavier and more difficulty hauling it around. This can be mitigated somewhat by using neodymium drivers and lighter construction materials. There's an old adage about speakers... light, loud, low: pick any two. My true 3-way fEARful 15/6/1 uses neodymium drivers and has more internal volume than most 15" cabinets, which allows it to go deeper and louder than most, plus it uses lighter construction to keep weight down, though it is not as easy to carry as a Subway 15.

 

[Franz975]

It may not be legally imported or sold into the US by our federal law.

Okay nice to know

Strange conclusions, and I have never heard the comment that the Subway 410 sounds thin, they have more low frequency extension than the Powerhouse Traditional 410, by quite a bit actually.

Oh okay, it didn't hit me as much as the older powerhouse :/ the actual one sound maybe more boxy compare to the agressiveness of the traditional ones

 

[gtirard]

Oh okay, it didn't hit me as much as the older powerhouse :/ the actual one sound maybe more boxy compare to the agressiveness of the traditional ones

OP here. May we come back to the topic of this thread please? (Jad Freer Sisma)

I'd like to comment about what I saw a few comments ago, about the class D / class G difference.
I don't know the technical aspect behind Sisma, all I know is that I love the sound.

When I bought it, the fact that it was using a class G power section wasn't a selling for me because I have nothing against class D amps, and I don't care as long as it sounds great.
So I don't know if the magic of Sisma comes mainly from its preamp, or mainly from it class G power section, or both.

So I wonder, has anybody ever tried to compare how a good preamp (for example Jule Monique, or the Noble, or Arkham Oracle, or whatever) into a normal power amp based on an Ice module - with the same preamp into Coda (the JF power amp, same class G power section as Sisma)?

It would be interesting to know how Sisma's class G power section compares to regular class D power amps…

 

[12bass]

Guessing it is combination of both preamp and power amp. I remember an engineer friend telling me years ago that power amplifiers were all pretty much the same. Then I listened to a bunch of them and noticed significant differences. However, I wouldn't necessarily equate the differences according to amplifier class so much as specific design implementation. Some designs sound better than others. Would love to hear the Sisma!

 

[Jim C]

OP here. May we come back to the topic of this thread please? (Jad Freer Sisma)

I'd like to comment about what I saw a few comments ago, about the class D / class G difference.
I don't know the technical aspect behind Sisma, all I know is that I love the sound.

When I bought it, the fact that it was using a class G power section wasn't a selling for me because I have nothing against class D amps, and I don't care as long as it sounds great.
So I don't know if the magic of Sisma comes mainly from its preamp, or mainly from it class G power section, or both.

So I wonder, has anybody ever tried to compare how a good preamp (for example Jule Monique, or the Noble, or Arkham Oracle, or whatever) into a normal power amp based on an Ice module - with the same preamp into Coda (the JF power amp, same class G power section as Sisma)?

It would be interesting to know how Sisma's class G power section compares to regular class D power amps…

I spent some time trying my tube Ampeg SVP-CL tube pre-amp into class AB and Class D power amps.
The two class AB amps I tried (Ampeg SVP1600 and Crest CA6). The tone was very nice.

For class D I used the effects send/return of of a GK MBF800. It did not work well and it's not because of the amp. It works great as a MI amp but think there must have been an impedance issue. I need to try this again with a proper Class D rackmount head but wanted to warn anyone that was thinking about trying a Capo or Noble pre with their normal MI amp. Maybe I just had an oddball combination.

 

[Admiral Akbar]

I spent some time trying my tube Ampeg SVP-CL tube pre-amp into class AB and Class D power amps.
The two class AB amps I tried (Ampeg SVP1600 and Crest CA6). The tone was very nice.

For class D I used the effects send/return of of a GK MBF800. It did not work well and it's not because of the amp. It works great as a MI amp but think there must have been an impedance issue. I need to try this again with a proper Class D rackmount head but wanted to warn anyone that was thinking about trying a Capo or Noble pre with their normal MI amp. Maybe I just had an oddball combination.

I don’t know if it matters, but then there’s the whole class D “ice” vs. “hypex” thing. I wonder which class D module Sisma and Coda use?

 

[Franz975]

I don’t know if it matters, but then there’s the whole class D “ice” vs. “hypex” thing. I wonder which class D module Sisma and Coda use?

They don't use class D. They use a propraetary Class G module that Jad Freer design themself with custom made pieces and switching power supply.

 

[Admiral Akbar]

They don't use class D. They use a propraetary Class G module that Jad Freer design themself with custom made pieces and switching power supply.

Ah my bad — as if I haven’t been reading this thread mentioning about 50 times the class G nature of the Sisma lol.

‘what I was trying to ask Jim C was in reference to his running SVP-cl into lead sled with great success, then less success with the effects return of a class D amp. I was wondering if ICE vs Hypex class D amps would make any difference.

 

[Franz975]

Ah my bad — as if I haven’t been reading this thread mentioning about 50 times the class G nature of the Sisma lol.

‘what I was trying to ask Jim C was in reference to his running SVP-cl into lead sled with great success, then less success with the effects return of a class D amp. I was wondering if ICE vs Hypex class D amps would make any difference.

I don't heard that much about Hypex preamp so I am definitely interested.

It is more recommended to put the Capo pre in the Return of in front of the Amp ? (I have a Bergantino at the moment)

 

[Admiral Akbar]

I don't heard that much about Hypex preamp so I am definitely interested.

It is more recommended to put the Capo pre in the Return of in front of the Amp ? (I have a Bergantino at the moment)

Capo to the effects return of the Bergantino will be fantastic, I’d think!

ICE/Hypex (from my limited understanding) are two versions of the class D power amp. A lot of TB’ers seem to feel Hypex has more “slam” (I’m gonna run and duck for cover… I said the “S-word” (slam).

 

[agedhorse]

A lot of folks who “think something” have never done double-blind testing. That’s where opinions go to die and real differences are identified.

 

[Danny C]

I'm just sittin back, listening learning and sometimes laughing. Ya'll have a great holiday, Enjoy!

 

[Mayo Fan]

So enjoyable how this thread keeps derailing with off topic and irrelevant generalized statements. Keep em coming folks, give me something to read in between all the xmas family stuff