Does class D have the Heft of SS

[jnewmark]

I'm not believing that a HPF reduces the functional bass Heftons (FBH)

Headphones, earphones can easily do let's say 15hz and filtering out below 30hz does nothing to the FBH in the sound.

I'm guessing usable functional heftons (UFH) are way up at 60-70hz, but the majority hear them at 100-120hz as super engergized heftons (SEH)

Of course, class-d can pass ultra low heftons (ULH) down to 0hz, a few early amp makers didn't account for this and passed through destructive heftons (DH). The ones you can't hear but destroy drivers.

Headphone (good ones), good music, or good synth, and EQ and listen for all hefton categories.
Somewhere there has to be an app for displaying hefton categories so we all can agree on which heftons are important.

I was in a band called The Heftons once. Does that count ?

 

[Jim C]

Time for some comparison testing of amps and cabinets.
After 15 minutes, the GB cabinet is the best combination of loud, clean, clear, and portable.
The amps are all different flavors of great.
The SVT never ceases to impress and the adjustability of the Fender is really strong. Both are heavy and the note has a different sort of weight compared to the Fusion 800.
So far...

 

[svtb15]

That Fender amp is a beast.. It is PHAT and clean.. Nice

Time for some comparison testing of amps and cabinets.
After 15 minutes, the GB cabinet is the best combination of loud, clean, clear, and portable.
The amps are all different flavors of great.
The SVT never ceases to impress and the adjustability of the Fender is really strong. Both are heavy and the note has a different sort of weight compared to the Fusion 800.
So far...
View attachment 2809624

 

[seamonkey]

Phenomenal news just broke:
"Mixed Drivers do not have Hefton interference!"

Apparently there's no duality issue for heftons

 

[Mike Arnopol]

~
Yes, I was thinking about that while composing my last post, because I had also read Andy's comment about a @2KHz signal getting dopplered by a woofer which was also trying to move the distance required to reproduce something else at the low end.

It ought to work nicely if it doesn't drive up the overall price of the rig too much, which would depend in large part upon whether it was passively or actively crossed between the woofer and the mid driver.
~

What started me using any flters on the woofers is the advent of 14 guage toroidal inductors. I could always hear when a woofer was passively low passed.Really messed with the transients and other things. Steve asked me to try these new coils. I was amazed. They didn't mess with the low end at all. Really allowed me to have the drivers covering the areas they do best. I can manipulate the mids where filtering is required---lots more design flexibility. But these coils do cost $40 each.

 

[Jim C]

That Fender amp is a beast.. It is PHAT and clean.. Nice

Thanks to you!
I would have never even known about this amp had you not mentioned it awhile back.
I guess Fender didn't have the brand recognition for a powerful clean amp back then; it's a keeper for sure.

 

[seamonkey]

It all in the fingers
Bass players hand on left is radiating potential heftons and has flooded the entire audience.
Guitar players hand is desolate of potential heftons - no matter how many strings they have.

 

[DavesnothereCA]

My Mark Bass SA450 and LMII are class AB with SMPS

~
Even though they are discontinued, this is good info to have - Thanks !

The SA450 owner's manual Download MarkBass SA450 Owner's Manual does not specify what you said, unless I missed it, but if true, it demonstrates that a class AB power amp need not weigh a whole lot.

The manual says that the SA450 weighs 7.5 pounds, and is rated 500 Watts RMS into 4 Ohms, and 300 into 8.

Its sibling, the SD800, weighs the same and apparently puts 750 Watts RMS into 4 Ohms, and 450 into 8.

And these heads seem to have very decent EQ circuit, with 2 sweepable mid bands, 2 contour controls, and also something which I do not recall encountering previously - a bass control which is NOT SHELVING in response, instead being centred around 40 Hz they say (which the graph shows to be the case, but only when boosted), and I like that concept.

Such a bass control might reduce the need for an HPF (which these models do not mention having), as its peaking response would not boost subsonics much as much when boosted as a shelving response control would.
~

 

[DavesnothereCA]

What started me using any filters on the woofers is the advent of 14 gauge toroidal inductors. I could always hear when a woofer was passively low passed.Really messed with the transients and other things. Steve asked me to try these new coils. I was amazed. They didn't mess with the low end at all. Really allowed me to have the drivers covering the areas they do best. I can manipulate the mids where filtering is required---lots more design flexibility. But these coils do cost $40 each.

~
Interesting !

But $40 is still a lot less money/bulk/weight than a[n active] crossover and an extra power amp would be, and if it achieves the same effect, bonus !

So are you putting a capacitor across the woofer after the coil in series with the woofer ? (IIRC, that would give a 12dB/octave filter slope)

And tell us more then please, about the passive crossover parts, low to mid frequency, and your choice of mid driver.
~

 

[svtb15]

Some people hate them... Not me. I have the sister to it the TB1200 and have been using it for years. It's not as clean and Tidy sounding as your 800 Pro. Mine is a pretty wide sounding poweramp too if you use it with an external preamp.
I have had mine since the week it came out. Right after NAMM. It's still going strong and used it on a summer tour this year for one artist that prefered a more warm and saturated sound that i does well. It works well for rnb and an artist i'm working with alongside with delbert mcclinton
Im supposed to be doing that Delbert cruise this january actually.. Not sure what they will backline that gig with but Ill bring one of my class D amps just in case. PS. I Hate ships after seeing the titanic movie and read many books on it..
I need to get one of these Fender Pro 800 amps just to have..

Thanks to you!
I would have never even known about this amp had you not mentioned it awhile back.
I guess Fender didn't have the brand recognition for a powerful clean amp back then; it's a keeper for sure.

 

[BadExample]

What started me using any flters on the woofers is the advent of 14 guage toroidal inductors. I could always hear when a woofer was passively low passed.Really messed with the transients and other things. Steve asked me to try these new coils. I was amazed. They didn't mess with the low end at all. Really allowed me to have the drivers covering the areas they do best. I can manipulate the mids where filtering is required---lots more design flexibility. But these coils do cost $40 each.

~
Interesting !

But $40 is still a lot less money/bulk/weight than a crossover and an extra power amp would be, and if it achieves the same effect, bonus !

So are you putting a capacitor across the woofer after the coil in series with the woofer ? (IIRC, that would give a 12dB/octave filter slope)

And tell us more then please, about the passive crossover parts, low to mid frequency, and your choice of mid driver.
~

That is interesting! Mike, does the coil respond to frequency following the XL formula? Or does it get funky with the attack spike?

For those who have forgotten inductive reactance, XL, increased frequency or increased inductive reactance (them Henry thangs) should increase impedance (Z). IDK why I think about these things, it's not like I'm ever going to make my own crossover.

 

[Passinwind]

~
Interesting !

But $40 is still a lot less money/bulk/weight than a crossover and an extra power amp would be, and if it achieves the same effect, bonus !

So are you putting a capacitor across the woofer after the coil in series with the woofer ? (IIRC, that would give a 12dB/octave filter slope)

And tell us more then please, about the passive crossover parts, low to mid frequency, and your choice of mid driver.
~

If you wade through the fEARful build threads to the days before greenboy designed his own crossovers you'll find my old 12/6 crossover design, which used one of those Jantzen toroids. IIRC no one else ever built one to my actual spec though. I've been using them for about a decade in my DIY builds. They are quite bulky and heavy, and many of the bigger sizes cost quite a bit more than forty bucks these days, at least at retail. I've looked into winding my own, but building speaker cabs is something I prefer to leave to others these days.

 

[MordBass]

Thanks. That helps paint a clearer picture. What are the impedances of the cabs?

8 for the Ampeg, 4 for the Boogie and SWR

 

[tombowlus]

Some people hate them... Not me. I have the sister to it the TB1200 and have been using it for years. It's not as clean and Tidy sounding as your 800 Pro. Mine is a pretty wide sounding poweramp too if you use it with an external preamp.
I have had mine since the week it came out. Right after NAMM. It's still going strong and used it on a summer tour this year for one artist that prefered a more warm and saturated sound that i does well. It works well for rnb and an artist i'm working with alongside with delbert mcclinton
Im supposed to be doing that Delbert cruise this january actually.. Not sure what they will backline that gig with but Ill bring one of my class D amps just in case. PS. I Hate ships after seeing the titanic movie and read many books on it..
I need to get one of these Fender Pro 800 amps just to have..

Kirk:

As I have mentioned in the past, the Fender 800 Pro is, IME/IMHO, one of the best examples of that kind of blend of form factor, power and features in a bass head. Love mine!

 

[svtb15]

I remember now..
I only wish that you had them long enough to do a full rundown for BGM... IIRC , fender needed them returned before you could get the review completed.
Sort of a Thunderfunk on steroids and extended Lows and highs.. My fave feature is the ROOM BALANCE control.
I don't use 2Ω loads anymore like i used to. But It is rock solid at 2Ω even on hot summer outdoor gigs. at least my TB 1200 is.

Kirk:

As I have mentioned in the past, the Fender 800 Pro is, IME/IMHO, one of the best examples of that kind of blend of form factor, power and features in a bass head. Love mine!

 

[Pocket4]

Forgive me, is a HPF a shiny new gear acquisition or is probably a circuit in the amps that I own?

 

[BadExample]

HPF=High Pass Filter. If your amp is fairly modern it probably has one built into the pre-amp to reduce the energy eating sub-sonic frequencies from entering the amp.

 

[murphy]

The SA450 owner's manual Download MarkBass SA450 Owner's Manual does not specify what you said, unless I missed it, but if true, it demonstrates that a class AB power amp need not weigh a whole lot.

Funny...as they would always advertise the AB fact in their spec sheets.....LMIII was class D
and now it is not there...have to find my manuals from when I bought

 

[DavesnothereCA]

~
....The SA450 owner's manual Download MarkBass SA450 Owner's Manual does not specify what you said, unless I missed it, but if true, it demonstrates that a class AB power amp need not weigh a whole lot....
~

Funny...as they would always advertise the AB fact in their spec sheets.....LMIII was class D
and now it is not there...have to find my manuals from when I bought

~
As you noticed, I got the manual from a 3rd party site, and they do not have the product page from the original site captured either.

Doncha just LOVE 'information scatter' ?!

A similar thing happened when I was looking up the Mesa Subway D800 head the other day. - The web site product page did not mention that the watts were RMS, nor the THD numbers at all, but the downloadable owner's manual (linked from the same page) had the full info.

At least in THAT case though, when the product page is eventually gone/orphaned, the owner's manual will be the more complete compilation, for the Mesa.

And I did not check about the LMII nor LMIII yet, as I got distracted.

UPDATE : the product page for the SA450 [This invalid link has been removed] (link is on their discontinued page) makes no mention of the amp's class either.

Nor does the page for the LMII : [This invalid link has been removed] , though I got the owner manual from there just now.
~

 

[dukeorock]

I remember now..
I only wish that you had them long enough to do a full rundown for BGM... IIRC , fender needed them returned before you could get the review completed.
Sort of a Thunderfunk on steroids and extended Lows and highs.. My fave feature is the ROOM BALANCE control.
I don't use 2Ω loads anymore like i used to. But It is rock solid at 2Ω even on hot summer outdoor gigs. at least my TB 1200 is.

Used to have two 800 Pro's and a TB1200. Terrific amps!