Papa’s slot loaded open baffle version #2

[nautibuoy]

In essence: you cannot biamp these speakers without either

A) building a speaker mounted power sucking passove crossover
B) using DSP
C) using an analog/active crossover.

D) dedicated bandwidth limited amplifiers - I'm planning on using a follower with a FR that rolls off at 150-180Hz for my 'fullrange' driver (and probably the DIY Audio store ACN for the bass section).

 

[nautibuoy]

I enquired about purchasing a pair of Eminence Definimax 4015ULF units from Blue Aran, a UK distributer/reseller. The message I got back is thet the units have been discontinued.

I may have to cast around for an alternative.

Shame as I wanted to stick with Papa's recommended bass units.

 

[peppennino]

Papa recommended also other drivers, including cheap Beta15 abd said there's very little difference between a bass unit and another

 

[nicoch58]

all is relative ,the difference db from fr ...if you need to push the difference in THD are clear.....

 

[wg45]

I've got some time with my recently built F2J running the FR drivers in my SLOBs.

Just my opinion: all my Papa amps are excellent but I'm going to rank them driving the SLOBs as-

1. F2J
2. F1J
3. VFET
4. ACA

 

[peppennino]

ACA better than F3?

 

[wg45]

I haven’t listened to or built an F3 yet. I have both Chas’ new F3 boards and boards for Zen Mod’s LuDef. They are on the to do list, of course. I’m thinking the LuDef is next, now that a few fearless amp builders have gone before me.

 

[peppennino]

Ok, I remembered badly

 

[marconi118]

Did you ever tried the T-bass network to boost bass of open baffle! Search it here in diyaudio there is a long tread on it.
It uses a transformer to boost the bass by 6db

 

[peppennino]

'T'-bass drive for OB LF drivers.

The amplifier MUST be a SS NFB type with good damping figure. It should be 4 ohm continuous rated for use when this circuit drives an 8 ohm driver on an OB, and 2 ohm continuous rated when two 8 ohm drivers are driven in parallel. If of sufficient quality this same amplifier may also feed the wideband driver via a series capacitor, say 47 to 220uF, though with a damping resistor connected in parallel with the wideband driver voice coil, say 8.2 ohms accross an 8 ohm nominal driver.

Not so easy with most of the FW amps (+the cost of a 250VA donut). Still prefer an active device like B5/ACN or the simple new boost created by Papa for Speaker Camp 2022.

 

[Stanislav]

ACA better than F3?

you bet it is.

beauty is in the eye of the beer holder.

 

[peppennino]

I haven’t listened to or built an F3 yet. .

Love beer

 

[Stanislav]

yeah, but beers are like amplifiers, different...
Moretti, Peroni, Chimay, Leffe, etc.

 

[peppennino]

Yes, and someone prefer Peroni to Chimay...

 

[Stanislav]

I like Peroni.
I like Chimay too.
Different days, different weather, mood, food, you name it.

 

[peppennino]

ACA better than F3?

It wasn't my intention to express a judgment on tastes, it was only a bit of astonishment. Take it easy

 

[chromenuts]

I've got some time with my recently built F2J running the FR drivers in my SLOBs.

Just my opinion: all my Papa amps are excellent but I'm going to rank them driving the SLOBs as-

1. F2J
2. F1J
3. VFET
4. ACA

My experience with these amps (except the F1J) and a variety of SLOB projects and fullrange drivers has left me with the same feelings.

My first amp build was an LM4875 gainclone…not sure where I would place that as I haven’t listened to it in a while, but it would not be at the top.

I’ve wanted to build a J2 for a while now, and have a few different PCB interpretations…but I’m just as interested in the F3 and LuDef.

I’ve gotten it in my head that I’d like to try a “SLOB on steroids” by using my 15” Tannoy dual concentrics with some AE Dipole 18s I have.

As usual, any progress is at a snails pace.

 

[nicoch58]

I've got some time with my recently built F2J running the FR drivers in my SLOBs.

Just my opinion: all my Papa amps are excellent but I'm going to rank them driving the SLOBs as-

1. F2J
2. F1J
3. VFET
4. ACA

current vs voltage amp I suppose...with FR,can explain a bit ?
Tnx

 

[wg45]

current vs voltage amp I suppose...with FR,can explain a bit ?
Tnx

I’m just a greenhorn. But I do like the sound of voltage source amps in a full range application. ( Which is Papa’s point with these amps, I think.)

I wish the F1 and F2 got a bit more love. It would be nice to see the boards in the store.

 

[peppennino]

That give me more and more desire to build Chas' F1, not J since I cannot afford 4 SITs...