Well, assuming the measured specs I have are accurate and I assume they're 'close enough' to yours since they came from NP and he hasn't offered up any to the contrary, then short of mounting it on an OB XO'd to a mid-bass thru sub BW system, the BIB probably is the 'best of the rest' overall for getting it to go down to Fs with any authority, but the large cab is a bit too costly in both materials and room 'real estate' for most folks.
So, if size/weight/material cost really isn't an issue as you claim, then by all means try the BIB. Otherwise, in a relatively small size, you can try a TL stuffed to suit and if you can find an acceptable balance between stuffing density and making the driver sound 'dull', then build another to match it:
L = 67.375"
CSA (width x depth) = 150.82"^2
zdriver = 24.375"
This puts the driver a little high for most seated ear heights, but then these type drivers typically sound better a bit off axis and unless you only sit in the balcony or similar at live venues it's presentation is more like 'live'.
The vent will at least initially have a 150.82"^2 area, so if the cab is square, then it will be full internal width wide and ~12.28" high, but I recommend putting it on the bottom rear and experimenting not only with stuffing density, but also by clamping a gasketed board over the vent to try various smaller openings (lower tunings) as well as its distance from the wall or corner.
GM
So, if size/weight/material cost really isn't an issue as you claim, then by all means try the BIB. Otherwise, in a relatively small size, you can try a TL stuffed to suit and if you can find an acceptable balance between stuffing density and making the driver sound 'dull', then build another to match it:
L = 67.375"
CSA (width x depth) = 150.82"^2
zdriver = 24.375"
This puts the driver a little high for most seated ear heights, but then these type drivers typically sound better a bit off axis and unless you only sit in the balcony or similar at live venues it's presentation is more like 'live'.
The vent will at least initially have a 150.82"^2 area, so if the cab is square, then it will be full internal width wide and ~12.28" high, but I recommend putting it on the bottom rear and experimenting not only with stuffing density, but also by clamping a gasketed board over the vent to try various smaller openings (lower tunings) as well as its distance from the wall or corner.
GM
Open Balffle MOTH's
Thank you GM for the terrific suggestions. Last night I was reading about MJK's open baffle with a low cost Goldwood GW1850 woofer in a "H" box.
20 Hz to 20 kHz Dipole Speaker System
Link to his experimentation on his website: http://www.quarter-wave.com/Project08/Project08.html
Looked interesting.
-David
Goldwood Specs:
$69.95 PartsExpress
Designed for sound reinforcement systems, lead guitar and rhythm guitars, practice amplifiers for bass guitar, stage monitors, and vocal PA systems. They feature accordion paper surround, poly laminated paper cone, and a vented pole piece. * Power handling: 220 watts RMS/310 watts max
* Voice coil diameter: 2.5"
* Le: .6 mH * Nominal impedance: 8.0 ohms
* Re: 5.26 ohms
* DC resistance: 6.2 ohms
* Frequency range: 30-2,000 Hz
* Magnet weight: 50 oz.
* Fs: 30 Hz * SPL: 94.2 dB 2.83W/1m
* Vas: 18.50 cu. ft.
* Qms: 6.65 * Qes: 1.27
* Qts: 1.07 * Xmax:. 3.36 mm
* Net weight: 11-1/3 lbs.
* Manufacturer model number: GW-1858
* Dimensions: A: 18", B: 16-1/2", C: 7-7/8", D: 8-1/2", E: 1-3/4.
Thank you GM for the terrific suggestions. Last night I was reading about MJK's open baffle with a low cost Goldwood GW1850 woofer in a "H" box.
20 Hz to 20 kHz Dipole Speaker System
Link to his experimentation on his website: http://www.quarter-wave.com/Project08/Project08.html
Looked interesting.
-David
Goldwood Specs:
$69.95 PartsExpress
Designed for sound reinforcement systems, lead guitar and rhythm guitars, practice amplifiers for bass guitar, stage monitors, and vocal PA systems. They feature accordion paper surround, poly laminated paper cone, and a vented pole piece. * Power handling: 220 watts RMS/310 watts max
* Voice coil diameter: 2.5"
* Le: .6 mH * Nominal impedance: 8.0 ohms
* Re: 5.26 ohms
* DC resistance: 6.2 ohms
* Frequency range: 30-2,000 Hz
* Magnet weight: 50 oz.
* Fs: 30 Hz * SPL: 94.2 dB 2.83W/1m
* Vas: 18.50 cu. ft.
* Qms: 6.65 * Qes: 1.27
* Qts: 1.07 * Xmax:. 3.36 mm
* Net weight: 11-1/3 lbs.
* Manufacturer model number: GW-1858
* Dimensions: A: 18", B: 16-1/2", C: 7-7/8", D: 8-1/2", E: 1-3/4.
The cabinet that Moth recommended is 1.4 cu ft,with a 2.5 in dia port.
Internal dimensions are 39.25" h,8.5" w,7.5"d
Center of speaker is 7" down from the top,port is about 5" up from bottom of the base.
The base was made of 2 pieces,13"x12",and11.5"x10.5",with a .75"r roundover.
.75" thick Ply or MDF
Internal dimensions are 39.25" h,8.5" w,7.5"d
Center of speaker is 7" down from the top,port is about 5" up from bottom of the base.
The base was made of 2 pieces,13"x12",and11.5"x10.5",with a .75"r roundover.
.75" thick Ply or MDF
Aye, I remember seeing that one reviewed a few years ago (my only real contact with Moth). Here's a MathCAD generated 1/2 space plot assuming a 4in long vent. Look like an acceptable response to you? 😉
It's way too small (for a vented box) for that driver -it's low motor-power means it needs a big 'un.
It's way too small (for a vented box) for that driver -it's low motor-power means it needs a big 'un.
Attachments
Note that the OEM cab's vent was a lovely three cutout affair and only baffle thickness according to the published drawings, so the tuning is fairly high unless heavily damped from the rear: http://www.mothmuseum.com/mothaudio/cicadahi.html
GM
GM
Attachments
An externally hosted image should be here but it was not working when we last tested it.
The vent is .75" long,according to the plans
Don Bunce said:
FWIW, the published factory drawings puts the vent's center-line 35.42" i.d./36.17" o.d. from the top.
GM
I'd forgotten about these measurements: http://www.stereophile.com/floorloudspeakers/104moth/index4.html
GM
GM
I tried to upload the plans in my first post,but somehow it didn't work.
OK,if you prefer to measure down 36.42" from the top,you will get a point 5.33" from the bottom...I did say about 5".
So how much difference will .33" make?
Re: Good Cabinet Recommendations for MOTH?
These days I am playing with OB's. The only question is, "How much space
do you have to work with?"
😎
dw8083 said:
These days I am playing with OB's. The only question is, "How much space
do you have to work with?"
😎
GM said:
I thought that Art Dudley was inappropriately harsh in his review of the speakers, but
I also think that the enclosures were off the mark, as seen in the big-*** bump at 85 Hz.
The motor on this woofer is better than you might think. A good size OB is appropriate,
something like 3' X 5'. With OB you want a good woofer in conjunction with this driver -
currently I favor 15-18" with light cone, big magnet, and 20-25 Hz resonance.
A notch filter at 10 KHz is helpful, something easily accomplished with
an LRC filter with .25 mH, 1 uF, and 100 ohms in parallel, this network in series with
the driver. The 100 ohm value yields the flattest measurement, but I suggest that you
tweak it between 22 and 100 ohms to taste.
😎
>currently I favor 15-18" with light cone,
>big magnet, and 20-25 Hz resonance.
~ what Qts ?
assuming no eq and bafflewidth ~360' / (2*Fs)
where F3 ~ Fs
>big magnet, and 20-25 Hz resonance.
~ what Qts ?
assuming no eq and bafflewidth ~360' / (2*Fs)
where F3 ~ Fs
Re: Re: Good Cabinet Recommendations for MOTH?
Hmmm. I thought I got the only pair. Nice to see someone else received a pair as well!
Unfortunately, not enough room for that setup!
I thought about trying them in the Metronome until Scottmoose expressed doubts about their suitability for that purpose. I did get some info on the original dimensions of the Cicada cabinets, but no info on bracing, etc.
Nelson Pass said:
Hmmm. I thought I got the only pair. Nice to see someone else received a pair as well!
Nelson Pass said:
Unfortunately, not enough room for that setup!
I thought about trying them in the Metronome until Scottmoose expressed doubts about their suitability for that purpose. I did get some info on the original dimensions of the Cicada cabinets, but no info on bracing, etc.
You could do a ~aperiodic TL of that configuration. I actually looked at a couple of vent lengths when I ran the sim on the Circada cabinet; not surprisingly, given that it's far too small a volume for the driver if run vented, it didn't make a heck of a lot of difference from the POV that it never looked anything less than rubbish. It deserves to be in a better cabinet / baffle.
Scottmoose said:
What dimensions / bracing would you recommend as a suitable cabinet?
Thanks in advance...
Re: Re: Good Cabinet Recommendations for MOTH?
The room is 12 feet wide (3.66 meters) by 16.5 feet long (5.03 meters).
I'm unconstrained by size, other than that of the room dimensions. My current speakers are a pair of Magnepan 1.6QR's that I practically got for free. The MG 1.6QR's are 19w x 65h x 2d inches.
-David
Nelson Pass said:
The room is 12 feet wide (3.66 meters) by 16.5 feet long (5.03 meters).
I'm unconstrained by size, other than that of the room dimensions. My current speakers are a pair of Magnepan 1.6QR's that I practically got for free. The MG 1.6QR's are 19w x 65h x 2d inches.
-David
That's a bit constrained, but I could imagine you going with a pair
of 2 ft wide by 5 ft high, with the driver at 3' height.
We can talk about stuff more at BAF, if you're going.
😎
of 2 ft wide by 5 ft high, with the driver at 3' height.
We can talk about stuff more at BAF, if you're going.
😎
- Status
- Not open for further replies.