Papa’s slot loaded open baffle version #2

[wg45]

What sort of bass are you guys getting with this setup? I've never had open baffle before,
I assume it is just fine. With the 15 it should be fairly powerful, bass if not subterranean,
how would you describe it? Or maybe it is lower than I am thinking?

Thanks,

Russellc

Thanks, just what I wanted to hear. Do the relative sensitivities of the two drivers matter? I assume the trend would be the full range driver will have a higher efficiency than the 15 inch bass. Is there some efficiency parameters
between the two drivers that should be followed?

Seems like a really sweet design worth trying. Been wanting to try open baffle,
I was hoping it had some low end grunt so am even more interested.

Whoops, just noticed this is actively crossed over! That explains the matching levels. Nevermind!

Russellc

Yes, you blend the sound of the two drivers by adjusting the pots on the ACN/LX Mini crossover. You can adjust the FR or woofer drivers to be louder or softer. I adjust it by ear and find a combination that I like.

I suppose you could build a passive crossover for the speakers. It may not sound as good as using Papa's crossover.

My system is- speakers, two amps, ACN/LX Mini crossover, and a preamp. Your best amp for the FR.

My woofers are running on ACA monoblocks, since a channel went out on my old amp. Even at 15 watts, the woofers sound great. I don't think you need a big amp.

 

[Russellc]

Thanks again, yes I would want the cross over to be that active one for sure.
I have my old mule amp, a JBL 6230 power amp that would drive it fine, and other Pass clones if it doesnt.

russellc

 

[peppennino]

I think I'll try Eminence Delta15 (from my Pi Theater 4) for tests: do you think that Beta15 would be as good as or better? Or better to spend much more for (not so easy to find in EU) Defnimax?

 

[Nelson Pass]

I found both to be similar and did not develop a preference in this application.

 

[peppennino]

Thanks!

 

[Russellc]

How's this one look for this project?

https://www.amazon.com/Eminence-Ame...e2122e&pd_rd_wg=YpAdn&pd_rd_i=B0009N5VIE&th=1

Russellc

 

[peppennino]

It's 2mm Xmax more than ordinary Delta15 (but 4mm less than Definimax), Qts is a little lower...

 

[peppennino]

In EU maybe the Monacor SP-382PA bass guitar driver?

Impedance (Z) 8 Ω
Frequency range f3-4,000 Hz
Resonant frequency (fs) 25 Hz
Power rating (RMS) 150 W
Peak music power output (MAX) 300 W
Sensitivity 94 dB/W/m
Suspension compl. (Cms) 0.26 mm/N
Moving mass (Mms) 73 g
Mech. Q factor (Qms) 3.03
Electr. Q factor (Qes) 0.99
Total Q factor (Qts) 0.75
Equivalent volume (Vas) 270 l
DC resistance (Re) 7.0 Ω
Force factor (BxL) 10.87 Tm
Voice coil induct. (Le) 0.8 mH
Voice coil diameter Ø 50 mm
Voice coil former aluminium
Linear excursion (XMAX) ± 3.5 mm
Eff. cone area (Sd) 825 cm2
Magnet weight 1.2 kg
Magnet diameter Ø 142 mm
Mounting cutout Ø 355 mm
Mounting depth 139 mm
Dimensions Ø 385 mm x 150 mm

Not so big BL but seems nice for this application...

 

[nicoch58]

not guitar spk , 94db is low side as Qem this is because of 25hz not so usefull, vas is good ,try to simulate on OB sw

 

[peppennino]

With The Edge?

 

[Zen Mod]

Eminence can be easily bought everywhere in Eu

 

[peppennino]

Definimax sems hard to find. Maybe I'll go for Beta

 

[nautibuoy]

not guitar spk , 94db is low side as Qem this is because of 25hz not so usefull, vas is good ,try to simulate on OB sw

Nelson's SLOB isn't a typical open-baffle because of the slot-loaded bass - is there a simulation software package that accomodates the slot-loading aspect?

Also, the recommended Definimax driver is less efficient than the Monacor?

 

[peppennino]

We need to ask Pa

 

[nautibuoy]

My natural inclination is to stick with Nelson's recommended Definimax drivers but, as you say, they're hard to obtain and expensive.

I may still try the DeltaLite units I linked to a couple of pages back, I can get a pair for a good price and they could be swapped out for the Definimax units without any carpentry.

 

[Soundhappy]

Last years on the market, we see many new generation woofers
with strong neodymium magnets, they can be interesting to try..
For example 15" etc https://www.parts-express.com/search?order=relevance:desc&keywords=15 Neodymium woofer

 

[peppennino]

B&C are made in Italy
QTS is very low (no more than 0.3) in neo drivers

 

[Soundhappy]

Eminence Beta 15 8 Ohm – Thomann France

 

[nicoch58]

Nelson's SLOB isn't a typical open-baffle because of the slot-loaded bass - is there a simulation software package that accomodates the slot-loading aspect?

Also, the recommended Definimax driver is less efficient than the Monacor?

yep I not mentions Qts.....Db is relate to fullrange ,we need at last 6db more and 35/40 Hz is more realistic in OB
sw Tolvan Data
PS Pa use biamp active with some boost too

 

[peppennino]

Don't need hieff woofer in biamb with B5 or ACN. Woofer EQ is a need, not an option: Slotted OB are designed for (see Papa's article)