High efficiency pro woofer driver

[Eldam]

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

Hi,

What was the bass driver please you choosed with this Beyma ? And how did you managed the bafle step in relation to the upper range driver ? (XO ?)

Btw what do you prefer today instead the Beyma you used to ?

@ at the OP: PHL Audio seems to make good sounding drivers despite the lacke of curve measurements in the datasheet ! Sometimes I have to ask myself if the french really want to sell their drivers abroad !

if you look too ar EMS Speakers site, despite the strong reputation of the owner family, the partial measurement is hatd to believe (no off axis measurements or full range measurement, no IEC measurement....🙁

 

[hollowboy]

You could make an absorbent phase plug (can be seen on some tweeters - a circle of a certain size but in this case made of absorbent material in front of the woofer membrane). Make it damp the high frequencies on-axis and slightly off-axis and then as you go further off-axis the frequency response drops naturally because of membrane radius. The circle should not be very large in diameter but that must be measured so you could get a good blend of transition from on-axis to off-axis. Distance from membrane influences too. Than you can expand experimenting with it and do not make absorbent circle but absorbent slight inward cone or absorbent hemisphere so reflections of non absorbed sound would not go back to membrane etc. With a little imagination sky is the limit and measuring equipment is your best friend.

I've thought about doing approximately the same thing by adding a heavy cover (e.g. perforated steel) to the woofer, and mounting a layer of felt / foam / whatever on part of the inside surface of that, to eat the on-axis HF. Possibly less fiddly & less likely to damage the driver.

Maybe on topic (since the OP has DSP): with this sort of mesh, I've considered mounting a tweeter into the perforated steel, coaxial to the woofer, and applying digital delay to the tweeter's input. That would result in an approximation of a point source driver.

 

[oon_the_kid]

Hi,


@ at the OP: PHL Audio seems to make good sounding drivers despite the lacke of curve measurements in the datasheet ! Sometimes I have to ask myself if the french really want to sell their drivers abroad !

if you look too ar EMS Speakers site, despite the strong reputation of the owner family, the partial measurement is hatd to believe (no off axis measurements or full range measurement, no IEC measurement....🙁

The PHL speakers look quite interesting. A bit on the more expensive side of things, but looks nice. Not planning on getting it at this stage. Just getting my feet wet. Wish they had graphs so I'd be more convinced..

The ems looks even more expensive..

Oon

 

[oon_the_kid]

I've thought about doing approximately the same thing by adding a heavy cover (e.g. perforated steel) to the woofer, and mounting a layer of felt / foam / whatever on part of the inside surface of that, to eat the on-axis HF. Possibly less fiddly & less likely to damage the driver.

Maybe on topic (since the OP has DSP): with this sort of mesh, I've considered mounting a tweeter into the perforated steel, coaxial to the woofer, and applying digital delay to the tweeter's input. That would result in an approximation of a point source driver.

Interesting idea. I did think of using a half inch tangband dome on my 15 inch audio Nirvana. Never thought about using minidsp to do a delay.

 

[oon_the_kid]

I've been playing with pro woofers for quite some time. Recently i've been playing with low-eff speakers because i can't accommodate large cabinets now and won't be able to for at least a couple of years. Pro woofers needs xover (passive or active) or they either must be heavy modified or have very specific cabinets or both to work properly without xover of some sort.



Seas A26RE4 does not have breakup because it has Le = 3.8mH - They practically incorporated 6dB/o filter in it. But in some manner you are right so i'll rephrase - i don't know of any driver that can work well with no crossover.

If you already made up your mind about what you want to buy and just asking for confirmation i can't help you.

I'd look at the Eminence B102 if i were you. Cutting the whizzer cone and damping the dustcap with felt might just be enough to remove some energy (and probably resonance) above 2KHz. You could make an absorbent phase plug (can be seen on some tweeters - a circle of a certain size but in this case made of absorbent material in front of the woofer membrane). Make it damp the high frequencies on-axis and slightly off-axis and then as you go further off-axis the frequency response drops naturally because of membrane radius. The circle should not be very large in diameter but that must be measured so you could get a good blend of transition from on-axis to off-axis. Distance from membrane influences too. Than you can expand experimenting with it and do not make absorbent circle but absorbent slight inward cone or absorbent hemisphere so reflections of non absorbed sound would not go back to membrane etc. With a little imagination sky is the limit and measuring equipment is your best friend.

Cheers

I am not looking for confirmation on the faitalpro. I am looking for alternatives, but I am using that as benchmark. Something with a lighter cone, better efficiency, decent Xmax and lower Fs without a rise in frequency response .. It is possible, the Dayton audio pm220 is almost already there, except for the suckout and rising response. I also come across very interesting speaker recommendedation from great plains audio. So it is interesting.

Thanks for the advice. Haven't done driver surgery before. I think I will get some really cheap speakers pioneer bofu to try this out first... But at the moment I think I will use everything as stock first... There is a reason why I am kinda sticking to 8 inch... Already have a box with an 8 inch hole...

Oon

 

[Zvu]

I've thought about doing approximately the same thing by adding a heavy cover (e.g. perforated steel) to the woofer, and mounting a layer of felt / foam / whatever on part of the inside surface of that, to eat the on-axis HF. Possibly less fiddly & less likely to damage the driver.

Maybe on topic (since the OP has DSP): with this sort of mesh, I've considered mounting a tweeter into the perforated steel, coaxial to the woofer, and applying digital delay to the tweeter's input. That would result in an approximation of a point source driver.

You could make layers with 1cm felt, 1cm foam and 1cm synethic wool - generally going from thinner to denser material. I would mount it like this:

 

[oon_the_kid]

Now, that there was mention of French loudspeakers. I just remembered this loudspeakers quite famous in the full range forum... Supravox. There are some interesting write ups using it.. With a cone mass of only 10 grams and the fantastic efficiency.. This would have been my ideal choice... Now if only it wasn't so expensive...

http://www.troelsgravesen.dk/SupravoxDTQWT.htm

Sent from my D6653 using Tapatalk

 

[zmyrna]

if looking for 8" with light cone (<10gr)
look at visaton b200
much cheaper than supravox
visaton bg20 even cheaper (need to remove the whizzer cone)

 

[LineSource]

Thus I'd be tempted (as Linesource was saying) to convert one pair into regular woofers for use to 2kHz - remove the whizzer from the ps220, then add several grams of cone treatments* to smooth the response and deaden the HF a little. As the article says of the PM220

Even though this is a “wideband” device, it still has the directivity of any other 8” piston, so crossover frequencies above 2 kHz will degrade a system’s power response.
​

A few high efficiency 8" midranges show very modest beaming at 2Khz, such that a standard dome tweeter can have a smooth polar blending if a 3rd or 4th order crossover is used. Several recommendations for this approach.

If you cross a wide bandwidth 8" at a high frequency where significant beaming occurs, you will want a tweeter which has a directivity pattern which matches this polar response of midrange. You can add a waveguide to the tweeter to get a smooth, continuous polar pattern match. Or, similar to the Bache 001, you can use a tweeter which includes a horn which will project a separate-and-different polar pattern which is designed to blend with the midrange "only over a modest listening distance" like 9'-12'.

Side-Side woofers can match the efficiency of the 8" with a narrow, low diffraction cabinet like the Kronos example. Two SB_Acoustics SB23NRX45-8 model well.

 

[badman]

I've used felt in front to soak up midrange from woofer cones- it's a perfectly valid way to get a bandpass (though it can act as a phase plug and actually widen dispersion in some respects, the net effect is generally "less" treble)

 

[oon_the_kid]

if looking for 8" with light cone (<10gr)
look at visaton b200
much cheaper than supravox
visaton bg20 even cheaper (need to remove the whizzer cone)

Hey, thanks. They are really cheap and I can get them from rs components... Will buy one to try one of these days

Oon

 

[oon_the_kid]

http://www.troelsgravesen.dk/JA8008.htm

I almost forgot this one. Pricey stuff at over 200 bucks but looks interesting ... How I wish speaker grew on trees...

Oon

Sent from my D6653 using Tapatalk

 

[Ro808]

Reading through this thread I wondered why the JA8008 was not mentioned... Until the above post 🙂
I have been searching for 'ultimate' high efficient drivers for some time now, the kind that 'have it all'. As mentioned earlier: these don't exist (anymore) or would cost a small fortune.
The SEAS RA26 might be the only driver available specifically designed to have a natural rolloff. Originally an OEM project, which was cancelled while the woofer was close to 'production stage'. SEAS decided to use it in the Dynaco A25 clone kit. A slightly modified RA26 has been used in Devore's Orangutan O/96, where 96 was supposed to refer to 96dB efficiency. Anybody with a little understanding of driver technology would raise the eyebrows at the notice of such claim. Evidentally this turned out to be (another) false prophecy, similar to other supposed to be highly efficient highend speakers like Audio Note etc. Devore changed O/96 in O/93 which seems at least closer to the truth.
The RA26 is a unique driver with some nice characteristics (very low Fs and a nice freq. response), but it is far from very efficient.

As the OP mentioned that he has an 8" hole in his cabinet, does this imply you have already build a box?
The JA8008 is one of the very few efficient 8" drivers able to play down to 40Hz. However, it is by no means a PA driver, probably not even up to the level of torture a regular SEAS woofer would take.

 

[Ro808]

It appears the Orangutan O/93 is actually a 'new' product from Devore and does not replace the 0/96. Anyway, my brother has extensive experience with several iterations of the O/96 and while he liked them a lot (the upgraded MK2 with the Morel tweeters), he was not able to get decent results with anything less than 2x15Watt tube amps. 'Real' 96dB efficient speakers should be able to shine with 2x3watt SET.
I admit, most 96db loudspeakers of similar size won't play down to 25Hz and there we have it: no free lunch.

 

[oon_the_kid]

As the OP mentioned that he has an 8" hole in his cabinet, does this imply you have already build a box?
The JA8008 is one of the very few efficient 8" drivers able to play down to 40Hz.

Yup. Already have a test box of sorts which I used from another project. Hence the reluctance to move from it. I have a SEAS FA22 in it now. This is meant to be my experimenters system, trying different drivers for woofers and tweeters...

The JA 2002 is certainly interesting. Wish it didn't costs so much... I wonder where might be the cheapest place you saw it for sale...

 

[oon_the_kid]

I was looking at the eminence speaker series and I realise the beta 8, deltapro 8a and 8b fit in what I was looking for too, even though they are listed as midrange speakers. They go to about 100 Hz before rolling off...Fairly low mms about 16-19gram. And a sensitivity of 95db and 97 db. Anybody has any experience with the eminences?

Thanks

Oon

 

[Scott L]

I was looking at the eminence speaker series and I realise the beta 8, deltapro 8a and 8b fit in what I was looking for too, even though they are listed as midrange speakers. They go to about 100 Hz before rolling off...Fairly low mms about 16-19gram. And a sensitivity of 95db and 97 db. Anybody has any experience with the eminences?

Thanks

Oon

Yes. I have used the Delta Pro-8 at one time. It's actually a very good driver-for what it does. It's not really a mid range (to me, at least) it's more like a lower mid range. 2k tops. I have tried many many cone drivers for mid range, over the years, and all in the 6.5 to 8 inch range. Most all of the ones I have tried, including the 8fe200 had some serious cone cry (breakup) in the upper end of their operating range. The Eminence is the only one I had tried, that did not exhibit that nastiness. I'm not sure what you are trying to accomplish, but marrying a tweeter to this unit will be quite a challenge.
I tried mine with a jumbo-sized ribbon tweeter, and it only worked "okay" at best. I disassembled the installation shown in the picture, and concluded the
Delta-Pro8 would be one hell of a kick azz mid bass horn driver.

 

[oon_the_kid]

Yes. I have used the Delta Pro-8 at one time. It's actually a very good driver-for what it does. It's not really a mid range (to me, at least) it's more like a lower mid range. 2k tops. I have tried many many cone drivers for mid range, over the years, and all in the 6.5 to 8 inch range. Most all of the ones I have tried, including the 8fe200 had some serious cone cry (breakup) in the upper end of their operating range. The Eminence is the only one I had tried, that did not exhibit that nastiness. I'm not sure what you are trying to accomplish, but marrying a tweeter to this unit will be quite a challenge.
I tried mine with a jumbo-sized ribbon tweeter, and it only worked "okay" at best. I disassembled the installation shown in the picture, and concluded the
Delta-Pro8 would be one hell of a kick azz mid bass horn driver.

Thanks for the reply, it's good to hear from someone with first hand experience with both the driver. What I intend to do is to run it active with a tweeter either a dome or a ribbon. Haven't fixed on that yet. The amplifier is a class A current source amp, something similar to F2, but using an inductor as a constant current source. The current source amplifier will cause it to have a gain at Fs and the port resonant frequency. There will be a resistor in parallel with speaker to limit the gain. This will extend the frequency response in the bass. On the upper end, I plan to use -12 db octave probably at 3kHz to prevent going into cone break up. The tweeter will also have a -12db/octave filter at 3kHz. the reason I am choosing pro woofer is for the light cone and powerful motor for better details. I know the deltapro series has a motor about twice as powerful as the 8fe200. In short I want a reasonably flat speaker that is great in details. So which of the two is better in details, 8fe200 or the deltapro? The poor bass response will sorted by the bass gain by current source amp.

The higher the frequency I could crossover the better it will be, to move it away from the sensitive frequency region. But I also have to accept that 8 " will start to beam at about 3kHz.

Oon

 

[Scott L]

Thanks for the reply, it's good to hear from someone with first hand experience with both the driver. What I intend to do is to run it active with a tweeter either a dome or a ribbon. Haven't fixed on that yet. The amplifier is a class A current source amp, something similar to F2, but using an inductor as a constant current source. The current source amplifier will cause it to have a gain at Fs and the port resonant frequency. There will be a resistor in parallel with speaker to limit the gain. This will extend the frequency response in the bass. On the upper end, I plan to use -12 db octave probably at 3kHz to prevent going into cone break up. The tweeter will also have a -12db/octave filter at 3kHz. the reason I am choosing pro woofer is for the light cone and powerful motor for better details. I know the deltapro series has a motor about twice as powerful as the 8fe200. In short I want a reasonably flat speaker that is great in details. So which of the two is better in details, 8fe200 or the deltapro? The poor bass response will sorted by the bass gain by current source amp.

The higher the frequency I could crossover the better it will be, to move it away from the sensitive frequency region. But I also have to accept that 8 " will start to beam at about 3kHz.

Oon

Well, we are getting into the realm of discussion where: every "for instance" has a compromise. The Delta Pro is clearly the better driver, with more "punch", but (as we know) less upper frequency extension. Given your application, I would consider going with dual 8fe200's per side for greater flexibility to address the baffle step, which will also be in the range you wish to cover. In my test, I replaced the single delta Pro-8, with dual 6fe200's to do just that. Overall, it was a much better approach since the little Faital 6fe200's had obviously better upper mids. Using two of the eight inch 8fe200's should offer you almost as much punch as a single Delta Pro, provided you construct a solid/sturdy/damped baffle plate.

p.s. don't be surprised if you have to alter the potential "electrical" crossover points to yield the optimum "acoustical" point.

 

[oon_the_kid]

Well, we are getting into the realm of discussion where: every "for instance" has a compromise. The Delta Pro is clearly the better driver, with more "punch", but (as we know) less upper frequency extension. Given your application, I would consider going with dual 8fe200's per side for greater flexibility to address the baffle step, which will also be in the range you wish to cover. In my test, I replaced the single delta Pro-8, with dual 6fe200's to do just that. Overall, it was a much better approach since the little Faital 6fe200's had obviously better upper mids. Using two of the eight inch 8fe200's should offer you almost as much punch as a single Delta Pro, provided you construct a solid/sturdy/damped baffle plate.

p.s. don't be surprised if you have to alter the potential "electrical" crossover points to yield the optimum "acoustical" point.

What do you mean by 'punch'? bass response? What about midrange detail, are they comparable?

Incidentally, you mentioned earlier that you had trouble marrying the ribbon to the deltapro. What was the issue? It didn't sound coherent? The sonic character is too different?

The ribbon tweeter you have looks huge, what tweeter is it?

Oon