High efficiency pro woofer driver

Status
Not open for further replies.
Jump to Latest
oon_the_kid

oon_the_kid

Member
Joined 2008
#1
Hi,

At a recent hifi show, I realised I preferred the sound of high efficiency speakers versus low efficiency drivers. I liked the sound of Audionote, Heco direkt etc. After some investigation, I figured out why I liked it, shares the similar characteristics as the other interest of mine, full range drivers. Powerful magnets and light cone. I plan to build an actively driven speaker with a current source amplifier based on this. The current source part, will give it a small boost around Fs and port frequency due to impedance increase. Most speakers that fit this category are actually pro woofers such as this one.

https://www.parts-express.com/faitalpro-8fe200-8-professional-midbass-8-ohm--294-1171

Just wondering if anyone who has done a similar project or has an interesting driver to recommend?

Thanks in advance


Oon
 
#2
I have run the Beyma 12P80Nd from a a few ohms to about 1000 ohm source impedance with great results. It is a very powerful and efficient driver and it can sound very good with current drive.. Very similar to a fullrange-driver.

You ideas seem very sound to me.

Cheers,
Johannes
 
#3
You think Heco Direkt's 95 dB can be squeezed out of an 11" hifi woofer?
I don't know exactly, but this is pretty much not possible at 2,83V/1m.

It does look appealing and I believe it sounds nice.

You don't need to actually do a project to know what to expect
in general from a driver, you just punch the numbers and plots
into a simulator and you're set. 8FE200 is more of a midrange
than a midwoofer.
 
#4
Yes you can squeeze that 95db number out easily but you must know where to look. The faitalpro 8" speaker is already 95dB. You need to look at the pro-speaker section rather than home speaker category.
The Fs is generally higher than the home speaker. And frequency tends to roll off higher. To compensate for that, I am driving it with current source amp.

Sent from my D6653 using Tapatalk
 
#7
#10
The 8" Tang Band W8-1772 is one favorite full range which should be available in Singapore. Extensive discussions on TL and MLTL cabinet options. I have the W8-1808 in our bedroom.

TT-2000
-----------
If you want an 8" + tweeter like AudioNote, you could cut the whizzer cone off the W8-1772 like the The Bache 001 speaker, or look at the low cost Dayton PM220 full range. The SB29RDN-004 is a low cost 94db sensitivity dome tweeter. (Dayton PM220 + SBacoustics SB29RDN)

Test Bench: Dayton Audio PM220-8 Wideband Neodymium 8? Woofer
----------------
PERHAPS, the next step up is a 12" or 15" COAXIAL speaker. The Altec(GPA clone) 604-8H is the historic favorite, but you will find diy-threads on several modern coaxials. Check which brands are fair priced in Singapore.
Radian 5210 popular 10" coaxial
Beyma 15CXA400Fe is one example of 95db/w
B&C 15CXN76 15CX76
 
#11
Lojzek said:
You don't need to actually do a project to know what to expect
in general from a driver, you just punch the numbers and plots
into a simulator and you're set. 8FE200 is more of a midrange
than a midwoofer.
Click to expand...

I agree, for pro use. But the OP is a guy who likes largish bookshelf speakers (Audio Note). The 8FE200 looks like an OK driver for doing such a 2-way.

I note that the 8FE200 is not really a 95dB speaker, in this context (used as a midbass, crossed at 2kHz). Most of the >95dB output of this driver is the on-axis region of mild breakup, 2-5kHz.

In the 100Hz-2kHz range (particularly looking off-axis) it looks like a ~93dB woofer with a ~3dB hump around 500Hz (on the test baffle).

Using AES standards, this nominally 8" driver should have had the FR plot recorded on a huge 1350 mm by 1650 mm test baffle. On a 'real' baffle in a 'real' room, it won't measure like this under ~700Hz. Using a narrow baffle, 20-25cm wide, should put the -3dB point due to baffle step losses at ~500Hz, which should (conveniently) cancel the hump shown on the spec sheet. Hopefully this would result in a system that's pretty flat down to about 300Hz, where room effects start to take over.

It should therefore be a good driver for cloning an Audio Note system, which also rely on room gain, and are of similar sensitivity:

"an estimated 92.5dB(B)/2.83V/m, though it should be noted that this is well below the specified 98dB figure"
From - Audio Note AN-E Lexus Signature loudspeaker Measurements | Stereophile.com

For a minimalist (Audio Note inspired) 2kHz crossover:

2 midbass: 8FE200
2 tweeters: Morel CAT 378 (robust, also 93dB)
2 1.5mH inductors*
2 5.6uF capacitors

That'd be about $300 total, from Parts Express (approximately 5% of the cost of the cheapest Audio Note).

...so I'd build a skinny box (maybe 25cm wide, to fit in some chamfering & allow the woofer to 'breathe'), and position them close to room corners.

Sealed ~30 litres: -10dB at 54Hz in free space. A current source amp might change the shape of the curve at the resonsnce peak (~96Hz), but will not improve the -10dB point. Near corners, the bass should be a little more plump. That might be enough.

Vented, 60-100 litres: should give a shelved-but-extended result similar to figure 4 of the previously linked Audio Note review, which shows a low tuned port, giving bass output that is ~7dB below the 100-1kHz band... which, when shoved into corners for a few dB of boundry loading, should end up reasonably balanced.

Note: the calculators on this site are OK for basic stuff (sealed boxes, rough/starting values for crossovers etc):
mh-audio.nl - Calculations

*textbook value is 1mH, but since the driver has an on-axis rise at 2kHz, I'd go a little bigger.
 
#15
hollowboy said:
I agree, for pro use. But the OP is a guy who likes largish bookshelf speakers (Audio Note). The 8FE200 looks like an OK driver for doing such a 2-way.

I note that the 8FE200 is not really a 95dB speaker, in this context (used as a midbass, crossed at 2kHz). Most of the >95dB output of this driver is the on-axis region of mild breakup, 2-5kHz.

In the 100Hz-2kHz range (particularly looking off-axis) it looks like a ~93dB woofer with a ~3dB hump around 500Hz (on the test baffle).

Using AES standards, this nominally 8" driver should have had the FR plot recorded on a huge 1350 mm by 1650 mm test baffle. On a 'real' baffle in a 'real' room, it won't measure like this under ~700Hz. Using a narrow baffle, 20-25cm wide, should put the -3dB point due to baffle step losses at ~500Hz, which should (conveniently) cancel the hump shown on the spec sheet. Hopefully this would result in a system that's pretty flat down to about 300Hz, where room effects start to take over.

It should therefore be a good driver for cloning an Audio Note system, which also rely on room gain, and are of similar sensitivity:

"an estimated 92.5dB(B)/2.83V/m, though it should be noted that this is well below the specified 98dB figure"
From - Audio Note AN-E Lexus Signature loudspeaker Measurements | Stereophile.com

For a minimalist (Audio Note inspired) 2kHz crossover:

2 midbass: 8FE200
2 tweeters: Morel CAT 378 (robust, also 93dB)
2 1.5mH inductors*
2 5.6uF capacitors

That'd be about $300 total, from Parts Express (approximately 5% of the cost of the cheapest Audio Note).
Click to expand...

Amen, Reverend.
This calculus is why I started to 'Roll my own'.

The following should look familiar to anyone who has seen a DeVore 0/96 up close.

How much is nice veneer and cone 'treatment' worth, really?



Sent from my Nexus 6 using Tapatalk
 
#16
oon_the_kid said:
Hi,

At a recent hifi show, I realised I preferred the sound of high efficiency speakers versus low efficiency drivers.
Click to expand...
I've been a HE fanboy since about 2000 when I brought some of my PA components inside, in between speakers.

I'm not sure if the Faital pro driver you mentioned is the same, but 'Javs' did some surrounds with a FP driver of the same size in an MTM with Beyma TPL150H. The thread is on AVS in the DIY section, but I'm having trouble logging in so can't find the thread to link it. Search under his name.

I was actually so impressed with the drivers (I've probably got >50 HE drivers here of various brands, and have owned many more) that I ponied up for 6 of the FP coaxes to try out. I've yet to measure them though.
 
#18
Brett said:
I was actually so impressed with the drivers (I've probably got >50 HE drivers here of various brands, and have owned many more) that I ponied up for 6 of the FP coaxes to try out. I've yet to measure them though.
Click to expand...

Hey Brett care to share with us some of the HE woofers that you have come across that you found really interesting and worth mentioning?

Oon
 
#20
LineSource said:
The 8" Tang Band W8-1772 is one favorite full range which should be available in Singapore. Extensive discussions on TL and MLTL cabinet options. I have the W8-1808 in our bedroom.

TT-2000
-----------
If you want an 8" + tweeter like AudioNote, you could cut the whizzer cone off the W8-1772 like the The Bache 001 speaker, or look at the low cost Dayton PM220 full range. The SB29RDN-004 is a low cost 94db sensitivity dome tweeter. (Dayton PM220 + SBacoustics SB29RDN)

Test Bench: Dayton Audio PM220-8 Wideband Neodymium 8? Woofer
----------------
PERHAPS, the next step up is a 12" or 15" COAXIAL speaker. The Altec(GPA clone) 604-8H is the historic favorite, but you will find diy-threads on several modern coaxials. Check which brands are fair priced in Singapore.
Radian 5210 popular 10" coaxial
Beyma 15CXA400Fe is one example of 95db/w
B&C 15CXN76 15CX76
Click to expand...
Thanks linesource,

Actually I already have 2 8" fullrange I can use for this duty, the ps220 from Dayton, which is pm220 sister and seas FA22. the ps220 has a mms of 8 gram and fa22 a cone weight of only 12 grams. The fa22 has an additional benefit of having an Fs of 30 Hz. However they both present another challenge, that is they require some sort of equalisation to deal with the rising frequency response at 1 kHz to about 10 or so db. This is one aspect that the HE pro don't have to deal with. But they generally have heavier cones at 20+ grams. I am generally targeting cone weights of about 15 grams if possible. I know, I am a bit anal about cone weights. The faitalpro 8fe200 fits the bill on that. But what I believe is the lighter the cone the less the momentum, hence the ability to follow the waveform more closely...

Oon

Sent from my D6653 using Tapatalk
 
Last edited:
Status
Not open for further replies.
Top Bottom