Proof of concept design help

[meccalli]

Hey guys, I was looking to test the waters of horn design with something cheap and locally available. Been looking at the Re audio rex 8 dvc. Been dabbling in hornresp for a while, not too sure what to make of the results coming from winisd, i know dips are theoretical to a perfect enclosure and the combined graph isn't too much different. Was wondering if anyone could mock up something workable with it, trying to get down low and fairly loud in contrast to a reflex. Simple offset folded tapped horn was where i was going.(i think)😀


Electrical Q Value -Qes: 0.38
Mechanical Q Value -Qms: 4.21
Total Speaker Q Value -Qts: 0.34
Free Air Resonance -Fs: 22.8 Hz
Equivalent Compliance -Vas: 27.1 liters
One-Way, Linear Excursion -Xmax: 12 mm
Efficiency -SPL 1W/1m: 81.2 dB SPL
Effective Piston Area -Sd: 195 cm^2
DC Resistance -Re: 3.2 ohm
Nominal Impedance -Znom: Dual 4 ohm
Thermal Power Handling -Pe: 175 W
Force Factor -Bl: 15.4

 

[meccalli]

Also, does the driver seems to be feasible for a TH?

 

[zlast]

Electrical Q Value -Qes: 0.38
Mechanical Q Value -Qms: 4.21
Total Speaker Q Value -Qts: 0.34
Free Air Resonance -Fs: 22.8 Hz
Equivalent Compliance -Vas: 27.1 liters
One-Way, Linear Excursion -Xmax: 12 mm
Efficiency -SPL 1W/1m: 81.2 dB SPL
Effective Piston Area -Sd: 195 cm^2
DC Resistance -Re: 3.2 ohm
Nominal Impedance -Znom: Dual 4 ohm
Thermal Power Handling -Pe: 175 W
Force Factor -Bl: 15.4[/QUOTE]


Your driver has a VERY low efficiency (81 db). If you looking for a efficient subwoofer, use
a driver with a higher sensitivity (more efficient).

 

[bjorno]

FYI

b🙂

 

[OscarS]

Electrical Q Value -Qes: 0.38
Mechanical Q Value -Qms: 4.21
Total Speaker Q Value -Qts: 0.34
Free Air Resonance -Fs: 22.8 Hz
Equivalent Compliance -Vas: 27.1 liters
One-Way, Linear Excursion -Xmax: 12 mm
Efficiency -SPL 1W/1m: 81.2 dB SPL
Effective Piston Area -Sd: 195 cm^2
DC Resistance -Re: 3.2 ohm
Nominal Impedance -Znom: Dual 4 ohm
Thermal Power Handling -Pe: 175 W
Force Factor -Bl: 15.4

Your driver has a VERY low efficiency (81 db). If you looking for a efficient subwoofer, use
a driver with a higher sensitivity (more efficient).[/QUOTE]

without going to a larger cone, the sensitivity can't be increase without giving up deep bass response. With it's low 22hz Fs, the potential of deep bass is what is gained by sacrificing sensitivity [the parameters are inter-related]. It's a triple edged sword when it comes to bass response. You can't just arbitrarily gain sensitivity without giving something up.

 

[zlast]

Your driver has a VERY low efficiency (81 db). If you looking for a efficient subwoofer, use
a driver with a higher sensitivity (more efficient).

without going to a larger cone, the sensitivity can't be increase without giving up deep bass response. With it's low 22hz Fs, the potential of deep bass is what is gained by sacrificing sensitivity [the parameters are inter-related]. It's a triple edged sword when it comes to bass response. You can't just arbitrarily gain sensitivity without giving something up.[/QUOTE]

I do not believe I stated any of the above...and 81 db is VERY low sensitivity. No parameters/specifications or design goals are stated. Perhaps 90 db peek output is ok, maybe not...simply suggesting that depending on his (unstated) goals, there might be better driver choices.

 

[David McBean]

FYI

b🙂

Hi bjorno,

Do you realise that you have FINALLY posted an input parameters screenprint with the record number shown 🙂.

4225 records means that you definitely qualify as a Hornresp "Grand Master".

Congratulations!

Kind regards,

David

 

[meccalli]

Wow, bjorno, you really went all out, thank you so much.... I'm beginning to see since modelling with hornresp that it's a lot more true to reality and lot more difficult to fine tune .Also didn't know hornresp could model t lines till I stumbled on it by accident. Once the horn became a line, the wizard shifted. I didn't really consider sensitivity too much since horns would improve the overall system but these graphs seem promising. Zlast, its just something to get me used to this new breed of enclosures, heard these woofers in many bass reflex/sealed systems so I know their sound is good. Will give this a go once i get some wood.

 

[bjorno]

Hi bjorno,

Do you realise that you have FINALLY posted an input parameters screenprint with the record number shown 🙂.

4225 records means that you definitely qualify as a Hornresp "Grand Master".

Congratulations!

Kind regards,

David

Thank you David...

Those are the HR Records I have in my Lap-Top and there are probably more in the 3 other PC: s I possess...In total?, I guess the number should be doubled.(I hav'nt tested HR.merge,Yet)

A late DIY Christmas Gift to you all: Recently I played with 'Pillow-Fill' stuffing and Polyester Fiber Batting material like:

Thermal-bonded Polyester Insulation Batts - Buy Wall Polyester Insulation Batts,Polyester Insulation Supplier,Polyester Insulation Batting Product on Alibaba.com

Perfect to be used in TH: s or any other quarter-wave designs where at least ~25% of the Volume that is left non-blocked, thus providing a free air path from the Throat to the Mouth with a low Air-flow Reststance.

...The outcome in pictures, of course(3).

b🙂

 

[bjorno]

..Will give this a go once i get some wood.

Hi meccalli,

Watch out for updates before cutting wood! HR updates are soon passing the speed of Moore's law...and don't poke with to many buttons at once and you will be safe.
Good Luck!

b🙂

PS: Found a 'Typo' in my previous posted calculation of Re Audio Rex 8 DVC coils. Corrected in a new Picture:

 

[David McBean]

Those are the HR Records I have in my Lap-Top and there are probably more in the 3 other PC: s I possess...In total?, I guess the number should be doubled.(I hav'nt tested HR.merge,Yet)

Hi bjorno,

If you would like to consolidate all your existing Hornresp records into the one master data file:

1. Make copies of the Hornresp.dat files currently in your three "satellite" PCs.
2. Rename those copied files Hornresp1.dat, Hornresp2.dat and Hornresp3.dat.
3. Transfer the renamed files to the laptop \Hornresp\Data\ folder.
4. Use the Hornresp File > Editor menu command to copy all records from Hornresp1.dat, Hornresp2.dat and Hornresp3.dat into the master Hornresp.dat file on your laptop.

Kind regards,

David

 

[tb46]

Hi bjorno,

Thanks so much for sharing the information in Post #9 and the updated example in Post #10. I cannot but agree with you: "...HR updates are soon passing the speed of Moore's law..." , and David hit it out of the park w/ his last one. 🙂

Regards,

 

[bjorno]

Pillow-Fill Measurements(Improved) + Picture Rev.

FYI,
Improved measurements of Material weights: ~ 100 times more accurate. Pillow-Fill low FR end measurements are more trustworthy by moving the Mic1 position to 1' and correcting the Density for both Pillow-Fill and the tested AP50 Polyester Batting.

Discard the earlier Picture= Pillow-Fill_Air-flow-Reststance_Absorption-Coefficient_Impedance.JPG

b 🙂