hi forum. about to start building my upper mid horns.
using dual 8" drivers, thinking reversed and using the magnet as a phase plug.
just curious on typical throat/mouth ratio, and typical flare shape used for a frequency of about 1.5k>4k
ive been thinking about 1/4 of the cone area for the throat, and up to 4x that for the mouth? is this about right? and what might a typical length be? i was trying to keep it somewhat short, around 300mm>400mm long.
i know this is pretty vague, but hopefully you guys can assist me
heres my driver>
Specifications:-
Type: 8” 150WRMS Subwoofer Driver 4 Ohms
Warranty: 12 Month
Brand: MaxAV
• Nominal Impedance: 4 Ohms
• Power Handling: 150WRMS, 300W Program Power (peak)
Test Parameter Data (T/S, Thiele/Small):
Rated Impedance: 4.2
Power Handling: 150WRMS
Program Power (peak): 300W
Nominal Diameter: 210mm (8 Inch)
Sensitivity (1m/1w/2.38v): 92
Frequency Range: 70Hz-5000Hz
Voice Coil Diameter: 50.5mm
Voice Coil Length: 10mm
Air Gap Height: 5mm
Winding Material: KSV
Magnet: 30 Oz
F0, Fs (Resonant Frequency): 70
Revc (D.C. Voice Coli Resistance): 3.6
Qms (Mechanical Quality Factor): 6.98
Qes (Electrical Quality Factor): 0.688
Qts (Total Quality Factor): 0.626
BL (Bl Factor): 6.7
Mms (Moving Mass): 18.73
Cms (Equivalent Air Volume to Cms): 245.39
Sd (Effective Surface Area): 21.38
Vas (Displacement Volume): 15.93
Levc (Voice Coil Inductance): 340.24
XMAX (Maximum Displacement): ±2.5
η0 (Efficiency): 0.82%
2pcs 8" 150WRMS PA DJ Speaker Subwoofer SUB Driver 8 Inch 4 Ohms Quality | eBay
using dual 8" drivers, thinking reversed and using the magnet as a phase plug.
just curious on typical throat/mouth ratio, and typical flare shape used for a frequency of about 1.5k>4k
ive been thinking about 1/4 of the cone area for the throat, and up to 4x that for the mouth? is this about right? and what might a typical length be? i was trying to keep it somewhat short, around 300mm>400mm long.
i know this is pretty vague, but hopefully you guys can assist me
heres my driver>
Specifications:-
Type: 8” 150WRMS Subwoofer Driver 4 Ohms
Warranty: 12 Month
Brand: MaxAV
• Nominal Impedance: 4 Ohms
• Power Handling: 150WRMS, 300W Program Power (peak)
Test Parameter Data (T/S, Thiele/Small):
Rated Impedance: 4.2
Power Handling: 150WRMS
Program Power (peak): 300W
Nominal Diameter: 210mm (8 Inch)
Sensitivity (1m/1w/2.38v): 92
Frequency Range: 70Hz-5000Hz
Voice Coil Diameter: 50.5mm
Voice Coil Length: 10mm
Air Gap Height: 5mm
Winding Material: KSV
Magnet: 30 Oz
F0, Fs (Resonant Frequency): 70
Revc (D.C. Voice Coli Resistance): 3.6
Qms (Mechanical Quality Factor): 6.98
Qes (Electrical Quality Factor): 0.688
Qts (Total Quality Factor): 0.626
BL (Bl Factor): 6.7
Mms (Moving Mass): 18.73
Cms (Equivalent Air Volume to Cms): 245.39
Sd (Effective Surface Area): 21.38
Vas (Displacement Volume): 15.93
Levc (Voice Coil Inductance): 340.24
XMAX (Maximum Displacement): ±2.5
η0 (Efficiency): 0.82%
2pcs 8" 150WRMS PA DJ Speaker Subwoofer SUB Driver 8 Inch 4 Ohms Quality | eBay
after rethinking about what you just said, @ 6db/oct there would be no real audible signal abover 800hz, and this is definitely not the case. are you sure youre thinking the right way around???
i need this to run upper mid range from about 1500hz up to 4000hz or thereabouts.
ill do a sine sweep with just the drivers in the car and have a listen and see what their usable range is, but its definitely much higher than 800hz.
i need this to run upper mid range from about 1500hz up to 4000hz or thereabouts.
ill do a sine sweep with just the drivers in the car and have a listen and see what their usable range is, but its definitely much higher than 800hz.
In a horn they will have no gain at higher frequencies.
"i need this to run upper mid range from about 1500hz up to 4000hz or thereabouts."
Not going to happen with this driver.
This driver has a mass corner of about 320hz. As we can see (with careful throat design), it's 3dB down at 500hz, and because of the inductance of the voice-coil, and the capacitance of the air in the throat chamber, it drops like a rock (at 18dB/oct) above there. The horn gain is about 8dB over a direct radiator box.
(Bill Woods, RCA fan)
Horn theory predicts that the 2226 will be about 4.5dB less than the 2220 in the 500hz region. Funny, that's how it measures too. LE15 is about the same mass corner as the 2226, but is 16Ω, so it's curve is parallel to the 2226, just about 3dB lower in level.
"i need this to run upper mid range from about 1500hz up to 4000hz or thereabouts."
Not going to happen with this driver.
This driver has a mass corner of about 320hz. As we can see (with careful throat design), it's 3dB down at 500hz, and because of the inductance of the voice-coil, and the capacitance of the air in the throat chamber, it drops like a rock (at 18dB/oct) above there. The horn gain is about 8dB over a direct radiator box.
(Bill Woods, RCA fan)
Horn theory predicts that the 2226 will be about 4.5dB less than the 2220 in the 500hz region. Funny, that's how it measures too. LE15 is about the same mass corner as the 2226, but is 16Ω, so it's curve is parallel to the 2226, just about 3dB lower in level.
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ok, just had a very quick play on HR with the driver specs i posted in first post.
i think the coil inductance is wrong decimal there. if i enter it as 0.34 i get a solid curve that matches what the driver sounds like which is -6db at about 1300hz. if i change the decimal to 3.4 then the -6db point is 250hz. which is definitely NOT what it sounds like.
i use them as full range, but mostly midbass drivers in my front doors, but they are definitively full range drivers compared to a "subwoofer"
i think im going to go ahead with using them for now. id be happier with a higher -6db point tho and im seeing the inductance being the reason for them being physically unable to produce higher frequencies, is this correct?
just to add, if i shift the decimal even further over i only get up to 2100hz as a cutoff frequency.
still yet to go and check them with a sine sweep.
i think the coil inductance is wrong decimal there. if i enter it as 0.34 i get a solid curve that matches what the driver sounds like which is -6db at about 1300hz. if i change the decimal to 3.4 then the -6db point is 250hz. which is definitely NOT what it sounds like.
i use them as full range, but mostly midbass drivers in my front doors, but they are definitively full range drivers compared to a "subwoofer"
i think im going to go ahead with using them for now. id be happier with a higher -6db point tho and im seeing the inductance being the reason for them being physically unable to produce higher frequencies, is this correct?
just to add, if i shift the decimal even further over i only get up to 2100hz as a cutoff frequency.
still yet to go and check them with a sine sweep.
this is what i have concluded to be the best compromise.
please correct me if im way off, but i feel with minor EQ adjustment at the XO points im sure this could be acceptable.
going to be running two of this driver, each in its own horn section, above a pair of eminence delta12a drivers each in a MT130 midbass horn. and then the same on the other side as left and right setups.
tweeter is a Selenium D220ti which should happily run down to 2khz.
off of which will be running on a MiniDSP 2x8 processor and each section will have its own amp channel. sub>kicker>uppermid>tweeter.
please correct me if im way off, but i feel with minor EQ adjustment at the XO points im sure this could be acceptable.
going to be running two of this driver, each in its own horn section, above a pair of eminence delta12a drivers each in a MT130 midbass horn. and then the same on the other side as left and right setups.
tweeter is a Selenium D220ti which should happily run down to 2khz.
off of which will be running on a MiniDSP 2x8 processor and each section will have its own amp channel. sub>kicker>uppermid>tweeter.
These cabs are full original design. So new I haven't even started designing it. Lol
So regarding that, I was going to fibreglass some nice horn flares but it's not going to happen in the timeframe I need it to. So just gonna run a more basic square shaped horn based on an exponential curve to each side and a mostly flat top and bottom. I'll run this driver reversed and make the plug fit snug around the magnet to give me the specs I came up with on hornresp.
All I can say is if I don't get what I'm expecting to hear then I'll just have to rebuild them to a more typical setup.
Before I start making dust tho, if I run a Simple slot shaped throat on the front of the driver, am I correct to think I'd get more upper frequency vs being reversed with a square perimeter style throat?
Reversing the driver does seem a bit "backwards" to me for higher frequencies. I just read it somewhere that it was a good idea.
So regarding that, I was going to fibreglass some nice horn flares but it's not going to happen in the timeframe I need it to. So just gonna run a more basic square shaped horn based on an exponential curve to each side and a mostly flat top and bottom. I'll run this driver reversed and make the plug fit snug around the magnet to give me the specs I came up with on hornresp.
All I can say is if I don't get what I'm expecting to hear then I'll just have to rebuild them to a more typical setup.
Before I start making dust tho, if I run a Simple slot shaped throat on the front of the driver, am I correct to think I'd get more upper frequency vs being reversed with a square perimeter style throat?
Reversing the driver does seem a bit "backwards" to me for higher frequencies. I just read it somewhere that it was a good idea.
one potential pitfall of "driver in reverse" is the distance from "driver frame to cone" as in can't get closer to cone/diaphragm because of magnet/basket assembly,whereas with cone forward you can get a phase plug much closer which is what will extend the upper limit of the horn.
ever see a Martin mid (phillishave's) inner workings?
ever see a Martin mid (phillishave's) inner workings?
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i hadnt, but just checked good ol google for a reference.
i think im just gonna keep it simple. ill mount them normal direction, ill make the throat chamber as feasibly small as possible, and ill then build to as close to my simulation spec as i possibly can. ill even have another little tweak on it by adding a throat chamber to the sim to see if i can wind up the upper midrange a tad. i need a little more around the 2khz mark.
i think im just gonna keep it simple. ill mount them normal direction, ill make the throat chamber as feasibly small as possible, and ill then build to as close to my simulation spec as i possibly can. ill even have another little tweak on it by adding a throat chamber to the sim to see if i can wind up the upper midrange a tad. i need a little more around the 2khz mark.
id like to put a bung of some sort infront of the cone to really minimise the volume in the throat chamber but if im reading what youre saying properly, you would advise to still have the driver mounted in its typical direction, and also to not have a narrow "slot" as the opening, but rather manufacture a plug system for, i assume, better distribution of sound pressure across the cone, and for a higher mechanical cutoff ??
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