6ND410 does look good.
If the graphs have the same resolution it might be a bit rougher (same resolution, ha).
With regard to amps, I tried a 6W 6P15P-EV SET on the efficient 16ohm 8NM610.
You’d assume it would be sufficient.
6W is not enough for some sort of “realistic” volume.
I think at least 30W is required (I’ve tried a few amps).
If the graphs have the same resolution it might be a bit rougher (same resolution, ha).
With regard to amps, I tried a 6W 6P15P-EV SET on the efficient 16ohm 8NM610.
You’d assume it would be sufficient.
6W is not enough for some sort of “realistic” volume.
I think at least 30W is required (I’ve tried a few amps).
Amps used have included:
KT150 PP in triode mode ~25W
Naim NAP 250.2 ~70W
Topping TP60 ~20W (surprisingly good when used with high efficiency)
The notch along the front side at mid and tweeter level is to inset half a 6” poly pipe as a roundover.
For completion, the woofer is an Oberton 12NB450 and the subwoofers have two 10” Peerless XXLS drivers back to back glued together with some timber in between.
The cabinet doesn’t vibrate.
Two bridged Behringer A500 amps.
All through Minidsp.
(The speakers have been painted the wall colour, they’re camouflaged!. My wife can’t even see them).
KT150 PP in triode mode ~25W
Naim NAP 250.2 ~70W
Topping TP60 ~20W (surprisingly good when used with high efficiency)
The notch along the front side at mid and tweeter level is to inset half a 6” poly pipe as a roundover.
For completion, the woofer is an Oberton 12NB450 and the subwoofers have two 10” Peerless XXLS drivers back to back glued together with some timber in between.
The cabinet doesn’t vibrate.
Two bridged Behringer A500 amps.
All through Minidsp.
(The speakers have been painted the wall colour, they’re camouflaged!. My wife can’t even see them).
Attachments
Looks like a good candidate. Too bad it has been discontinued. Unfortunately 18Sound has a 6" (that Scott mentions) and a 10" midrange driver now in their lineup, but no 8". Their midranges all have high sensitivity, which is a plus for my application.
Did you try other midranges too? How would you compare the 8NM610 sound to the others?
Are you actively xo?
I saw your comment about Minidsp, so my question about active xo was already answered.
Interesting 6W SET not being enough for a 102dB 16 ohm driver. What are the xo points you use around this driver? Slopes?
250 Hz and 2.4 kHz. 18 dB/octave.
With such a high Fs (259 Hz) I give a small amount of boost so that it is flat beyond 250 Hz before applying the crossover.
8” drivers over the years include:
KEF B200- (going waaaay back) the antithesis of efficiency, but can give good results in the right configuration.
Focal 7N303- similar cone material to B200 but quite a bit more efficient. Good results.
Focal 7? polyglass. Good results.
Focal 7? kevlar. Good results.
Audio Nirvana Super 8 cast- tried with both the whizzer on and cut off, better as a mid with the whizzer off. Can’t handle “realistic” volume.
Fostex FE206- with whizzer on and cut off. Can’t handle “realistic” volume.
The worst driver I’ve heard. Brittle, hard, grating sound. Likewise the FE204. I assume it's the paper cone (same in both).
PHY-HP- the cone is so thin you could blow your nose with it. The least detailed driver I’ve heard. Luckily I sold them for a good price.
I’ve also had good results with the 6” 18sound 6ND430. Not 8” of course.
The 8NM610 is the best. More detailed. More dynamic range.
With such a high Fs (259 Hz) I give a small amount of boost so that it is flat beyond 250 Hz before applying the crossover.
8” drivers over the years include:
KEF B200- (going waaaay back) the antithesis of efficiency, but can give good results in the right configuration.
Focal 7N303- similar cone material to B200 but quite a bit more efficient. Good results.
Focal 7? polyglass. Good results.
Focal 7? kevlar. Good results.
Audio Nirvana Super 8 cast- tried with both the whizzer on and cut off, better as a mid with the whizzer off. Can’t handle “realistic” volume.
Fostex FE206- with whizzer on and cut off. Can’t handle “realistic” volume.
The worst driver I’ve heard. Brittle, hard, grating sound. Likewise the FE204. I assume it's the paper cone (same in both).
PHY-HP- the cone is so thin you could blow your nose with it. The least detailed driver I’ve heard. Luckily I sold them for a good price.
I’ve also had good results with the 6” 18sound 6ND430. Not 8” of course.
The 8NM610 is the best. More detailed. More dynamic range.
I have been reading this forum for as long as it has existed. I can tell you know exactly what you are talking about, and furthermore, have to guts to post it. Touche !
Eighteensound 8NM610 is a sealed basket design; hence the high "system" Fs.
When I compare it's T/S parameters with the B&C 8PE21, it turns out that they are very comparable (same low Qt, same Mms, same Le, same Sd); Fs of 8PE21 is lower of course as it is a normal unit.
They even look pretty much the same with their shallow blueish cones and paper dust caps.
When pairing with the hornless TPL150, the sensitivity of the B&C is just perfect, so the higher SPL of the Eighteensound is not an advantage when using a passive crossover.
8PE21 is still available.
When I compare it's T/S parameters with the B&C 8PE21, it turns out that they are very comparable (same low Qt, same Mms, same Le, same Sd); Fs of 8PE21 is lower of course as it is a normal unit.
They even look pretty much the same with their shallow blueish cones and paper dust caps.
When pairing with the hornless TPL150, the sensitivity of the B&C is just perfect, so the higher SPL of the Eighteensound is not an advantage when using a passive crossover.
8PE21 is still available.
This driver is one of my favorites ..under limited conditions.
Yeah, it really can't handle realistic spl.. in fact it can't even handle moderate spl full-range with material that has a substantive dynamic range.
Not only is operational excursion pitiful, at higher pressure levels the whizzer's phasing/bending actually alters its freq. response under operation. I mean, while the impulse response is crap above about 1.2 kHz for a sweep condition - that's actually not representative of the response under normal operation: which is constantly changing.
..still,
With the right amplifier, with proper low pass AND high pass filters, the whizzer removed, the right loading (..which can't have much spl leaking out through the cone or delicate surround, and at the same time isn't generating resistance on the driver's motion),
-it can sound AWESOME. FAR more detailed and nuanced than most drivers, and particularly well-suited to improving apparent "low level" detail (relating to "image" position and structure, along with soundstage/environmental details about the recording.
In other words a "free air" w/large baffle or large volume vented enclosure that typically is operated between 200-800 (or 900) Hz (..depending on the design). Typically at least 2 drivers, and typically being "driven" by a high impedance out amp.
Thank you! Definitely provides perspective.
So I'm still digesting your insights. Can't get my head around it. 6W SET into a 102dB sensitivity and 16 ohm driver, 250 to 2400Hz, and is not enough for realistic volumes. Can I ask how loud is realistic volume for you? How large is your room?
On paper, a 102dB & 16 ohm driver looks great for my application. At least I thought so
My bandwidth will be narrower: about 400 to 2000Hz, so less power required. But I was also looking at using a less powerfull SET.
BTW, what do you use to power the TPL?
Thank you! Definitely provides perspective.
So I'm still digesting your insights. Can't get my head around it. 6W SET into a 102dB sensitivity and 16 ohm driver, 250 to 2400Hz, and is not enough for realistic volumes. Can I ask how loud is realistic volume for you? How large is your room?
On paper, a 102dB & 16 ohm driver looks great for my application. At least I thought so
My bandwidth will be narrower: about 400 to 2000Hz, so less power required. But I was also looking at using a less powerfull SET.
BTW, what do you use to power the TPL?
Because of two reasons:
1) the extra power that is required to e.q. this driver that is intended to be horn loaded, but is not.
2) Because it is being used down into the octave that requires a significant amount of power due to the programme content density. (250-500)
http://www.eighteensound.com/Portals/0/PDFs/8NM610.PDF
This driver looks great ! ......(on paper)
But I do have to wonder what it sounds like (?)
Could I hear the dustcap break up in the 2-3K Hz range ? (I wonder?)
https://www.parts-express.com/pedocs/specs/294-652--8pe21-spec-sheet.pdf
I had the 8PE21 in my prototype together with TPL150; passive crossover 2nd order / 2 kHz.
Sounded excellent; I did not hear a trace of coloration (for which I am pretty sensitive....that's why no horns for me).
For comparison I had an Audax HM210Z10; sounded a bit more colored and would need more attention in the crossover as it has a more rising response.
So I decided to continue with the B&C (bass enclosures with Faitalpro 15PR400 almost ready).
Sounded excellent; I did not hear a trace of coloration (for which I am pretty sensitive....that's why no horns for me).
For comparison I had an Audax HM210Z10; sounded a bit more colored and would need more attention in the crossover as it has a more rising response.
So I decided to continue with the B&C (bass enclosures with Faitalpro 15PR400 almost ready).
8PE21 dustcap ?
Thank you for your report ! I fully understand about horns. There are far more bad experiences with horns, than good ones.
I think I have asked you before, so if I am repeating, please forgive, but, can you tell me what kind of construction the dust cap on the 8PE21 is made of ?
I wish I knew just how excellent of a diver this was, back when I was trying something like you are doing now ! p.s. I think you will end up with a remarkable good system !
Thank you for your report ! I fully understand about horns. There are far more bad experiences with horns, than good ones.
I think I have asked you before, so if I am repeating, please forgive, but, can you tell me what kind of construction the dust cap on the 8PE21 is made of ?
I wish I knew just how excellent of a diver this was, back when I was trying something like you are doing now ! p.s. I think you will end up with a remarkable good system !
I was surprised that 6W isn’t enough too.
I used four monoblocks for the mids and the TPL. They didn’t have enough headroom- I couldn’t believe there was obvious distortion.
My room is 8m X 5m X 2.7m.
I mostly listen to classical/classic and jazz. Some modern stuff too. Eg Brian Eno.
The way I play the music none of them needs to stay loud, but they need to get loud.
At the moment I’m using two Topping TP60, so four channels for the mids and TPL.
I’m using a Naim NAP 250.2 on the 12”.
It’s a fine amp and I may end up using it on the TPLs.
The TP60 is a real surprise.
People talk about it as being acceptable for computer speakers.
Maybe it’s the high efficiency of the speakers but it’s a success.
You may be interested that I also tried the 8NM610 on the horn used for their published specs.
It’s the RCF designed for their equivalent 8” (correspondence).
It is not suitable for hifi, maybe at 50m plus, which is what it is designed for after all.
I used four monoblocks for the mids and the TPL. They didn’t have enough headroom- I couldn’t believe there was obvious distortion.
My room is 8m X 5m X 2.7m.
I mostly listen to classical/classic and jazz. Some modern stuff too. Eg Brian Eno.
The way I play the music none of them needs to stay loud, but they need to get loud.
At the moment I’m using two Topping TP60, so four channels for the mids and TPL.
I’m using a Naim NAP 250.2 on the 12”.
It’s a fine amp and I may end up using it on the TPLs.
The TP60 is a real surprise.
People talk about it as being acceptable for computer speakers.
Maybe it’s the high efficiency of the speakers but it’s a success.
You may be interested that I also tried the 8NM610 on the horn used for their published specs.
It’s the RCF designed for their equivalent 8” (correspondence).
It is not suitable for hifi, maybe at 50m plus, which is what it is designed for after all.
Eighteensound still has an 8" that should be usable as midrange, although it is not as efficient as the 8NM610: the 8NMB420.
But I don't have any experience with it. I own two pieces of his larger brother, the 10NMB420 which I intend to use for a WMTW. Those drivers have one advantage: An inverted dustcap, which is more resistant against "terrorist attacks" (i.e. immature fumblers and dome-crushers of all ages).
Regards
Charles
But I don't have any experience with it. I own two pieces of his larger brother, the 10NMB420 which I intend to use for a WMTW. Those drivers have one advantage: An inverted dustcap, which is more resistant against "terrorist attacks" (i.e. immature fumblers and dome-crushers of all ages).
Regards
Charles