Tone Tubby alnico hemp drivers

scorpion · « **Reply #120 on:** 19 Jul 2008, 06:22 pm »

Proably the Neo3 Dan, but very interesting. I think I for the purpose of the everlasting testing will try the Ceramics 8" and see how those work with SABA old Greencone Alnico tweeters. The one that Lampizator advocates. Might be a hit ! Otherwhise if tone is to my liking I finally might splurge into the 10" TT.

/Erling

Dmason · « **Reply #121 on:** 19 Jul 2008, 06:42 pm »

Erling,

I think that would be the choice, congrats; Kurt Chang has a-lot of experience with high-rotation speakerholism, is constantly changing things, and has a very well attuned ear for complex acoustic music; his observations are gold, and as I said, he is in love with the sound he is getting with just the guitar 8 speaker.

I have noticed that the Alnico gestalt isnt nearly as well imparted using solid state amps. using single ended or triode amps it is an "obvious" effect, so, one before the other, it would seem.

scorpion · « **Reply #122 on:** 19 Jul 2008, 07:15 pm »

In fact I have two of those Chinese Music Angels ready for big going over à la Lampizator and Dietmar Gerhold. One 845 SE but there is something wrong with its power supply, which I have to sort out, before I can progress. The other one is a KT88 just to be adapted and run in Triode mode to give some 30 watts of clean power. My next project.

/Erling

scorpion · « **Reply #123 on:** 19 Jul 2008, 07:39 pm »

'Speakerholism is the term', said Bill, 'Speakerholism it is', said Bull, to paraphrafrase a very good and popular Swedish childrens book. Twincats Bill and Bull are two torpedos used by the mean cat Mans. This would be a typical example of Bill and Bull conversation, laconic, intellectual and to the point.

OT, of course but better phrased.

/Erling

ttan98 · « **Reply #124 on:** 19 Jul 2008, 11:16 pm »

Quote from: nodiak on 19 Jul 2008, 04:42 pm

This is all interesting to me as have used the 1st gen FR8 (Hemp Acoustics) on ob with whizzers removed and phase plugs. I've tried some tweeters - Scanspeak 9300 in zaph style waveguide, and neo3pdr.

I too use Hemptone FR8 with the whizzers attached, I x-over around 3.5Hz using LR2, using DCX2496,and compression driver DE10 and ME10 horn, sounds much better than FR8 alone.

Do try it, cross at 3.5kz, I did some measurements, fairly flat off axis as well. I think at that freq.,the whizzer has no effect. The 9300 and Neo should should be able to cross at that freq.

cheers.

nodiak · « **Reply #125 on:** 21 Jul 2008, 09:44 pm »

ttan98, good to hear your experiences. The hobby is slowed down for me recently, not in the mode for more play with the FR8 and tweeters just now, but will again. Have tried cap and coil 1st order, and 3rd order ~ 3000hz, but most often like them alone best so far. No electronic xo or biamping. Also have some 4.5" alnico Pioneers that have clear highs and can be used like mid-tweeters, so a low xo point is possible with a woofer, 10-12" TT's could be nice.
Recently trying some Dammared FE127's that are pretty smooth, no flinching.
Mostly on the lookout for 10-12" bass support for these 127's and FR8's (15's overload my room). Thinking TT ceramics or Eminence 12LTA's.
This is a good thread.
Don

ttan98 · « **Reply #126 on:** 21 Jul 2008, 10:15 pm »

Someone at US Ebay is selling 12" TT Alnico(RED body) 2nd hand for $200. I thought someone here maybe interested?

androuski · « **Reply #127 on:** 22 Jul 2008, 05:50 am »

Nodiak,
I'm also thinking of designing a non-oversized OB with a 12" bass driver.
Don't you think that a 12" fane sovereign would be OK for this purpose ?
Here are the spec. :
http://www.fane-acoustics.com/pdfs/Sovereign12-125_SpecSheet.pdf
I can't find any feedback on the net...

Graham Maynard · « **Reply #128 on:** 22 Jul 2008, 07:31 am »

Hi Nodiak, (Apologies - I meant Androuski.)

I crossed that Fane off my list due the shape of the basket - too much metal reflecting back through the cone. Might be okay for instrument and PA.
I did choose this though;-
http://www.fane-acoustics.com/pdfs/Sovereign10-125_SpecSheet.pdf

and I am satisfied with its midrange. Cheap too!

This could probably work well with a simple C coupled tweeter. Also with a thin cloth grille 'crossover' on the Fane if necessary, but mine sounds flat enough when fully open and directly driven.

Cheers ......... Graham.

androuski · « **Reply #129 on:** 22 Jul 2008, 08:12 am »

That's a good thing to point out,
but I guess it would cause some reflection for a midrange purpose,
but what about a bass purpose, not higher than 150 hz ? I thought those long waves don't care about reflections... even more, maybe that kind of basket could work as a first bass enclosure ? Am I dreaming ?

painkiller · « **Reply #130 on:** 22 Jul 2008, 09:07 am »

Wow. I got my hands on a couple of Alpha 15A's. Boy, these drivers seem so cheap compared to the Super Boys. They're running in as we speak. They don't play much more bass than the Super Boys either. Really need to EQ the bass up to get any movement. Do I like it? Well... It's to early to tell, but so far I'd prefer a good old vented subwoofer with a plate amp.

So about these damping transformers. I really didn't quite understand what kind of transformer you meant. Just like a regular toroidal with 110V primary and say 25V secondary? Or is it some special kind of autoformer or something? Graham? Anyone? I think i'll need to dampen the midrange with about 6dB.

Graham Maynard · « **Reply #131 on:** 22 Jul 2008, 10:05 am »

Sorry Androuski.
I wrote to Nodiac by mistake from looking at the Topic Summary.

That 12" basket would be okay for LF with its low excursion <4mm, but neither Fane has a low Fs.

Hi painkiller,

Yes a line/mains transformer with the primary(ies) left disconnected would be fine. Something with two 20V windings or 40V centre tapped @ 3A or more per winding should be a good start.

If you try this it would be interesting to hear if it works with the Alphas too; I have tried it on low and medium Q drivers only.

Cheers ......... Graham.

androuski · « **Reply #132 on:** 22 Jul 2008, 10:56 am »

Don't be sorry

Actualy it's not a killer LF driver for an open baffle design, but quite good for who intends to do a cost-killer design...

Seems to be good :

- price
- qts

Doesn't seems good :

- excursion
- fs, I wish it lower

Supravox as an OB with a 12" driver for bass reinforcement with such an average FS (47hz), and even a lower qts (0,38), but long excursion (8mm), here it is :

http://www.supravox.fr/kits/panneauplan.pdf

I wonder if I this 12" from fane could go along with a little full range driver, such as a fostex or even a 3" tangband... I stop here because I'm off topic, sorry

nodiak · « **Reply #133 on:** 22 Jul 2008, 04:26 pm »

androuski, agree that driver won't give much bass. The graph shows it on IB, won't do any better on ob. What is the baffle width you are limited too? If 16" is ok then a 15 can work with wings, you could trim it to minimum at 15.5" even. Can be short, I use 32-36" tall baffles. A 12 will only be a little narrower but less bass. I'm thinking of 12's to avoid lower bass to not interfere with subs output. So we have different purposes in mind.
I'm just another hacker on the 'net but I think a 15 and a small Fostex or similar is one of the easiest ways to go. And that leads directly to Martins ob.
Another driver that is inexpensive is the Eminence 12LTA. I've been following talk of it and it seems to have great mids, add a tweeter (maybe a notch filter for mids) and you're good. Not Alpha 15 bass tho. But still needs some width for baffle, 24"+ they report - could go 14" + 5" wings. Maybe room lift will give you enough bass with these.
Everything depends on all the questions - *Room character is #1 especially to speaker placement, how loud you want to play, how much bass will satisfy, how far you sit from speakers, what compromises are willing to accept, etc.
Don

*not enough mention of this imo.

androuski · « **Reply #134 on:** 22 Jul 2008, 05:28 pm »

Indeed,
we don't have the same use in mind

Thanks for reply. I am quite a newbie so I don't really understand, for instance, where is the real difference between alpha 15 and fane 12" 's curves ; they are both in the same baffle configuration, and they show the same slope when going lower ; am I wrong ? In OB, bass from 50 or even 60 hz would be OK for me...

painkiller · « **Reply #135 on:** 23 Jul 2008, 09:22 am »

I had this big transformer lying around, so I hooked it up to the Superboy and tweeter to attenuate them. 15V 225VA. It actually did the job for bringing out the sufficient amount of bass from the Alpha 15A's. But the thing is that the Superboys are way too powerful. The amount of attenuation needed is so much that it really kills the incredible dynamics this driver is capable of.

Another problem also became apparent. There's no way to do a 1st order low pass filter on the Alphas. I don't like these drivers at all, and they muddy up the sound too much. Especially when allowed to play further up in frequency. And quite frankly they don't match with the tight dynamic sound of the Superboys. Just try tapping the cone with your fingers and the whole basket resonates with a hollow sound.

I'm really impressed with the 15" Superboys though. The dynamics are awesome. Detail is really stunning. Sweetness and 'thereness' is really something special. Because of the limited frequency extension (?) there is no beaming. The only downside is that they are so freakin' loud. You'd need somewhere around 10 OB woofers to get enough bass. It's starting to give me a head ache.

So I guess the only sensible option is to get one of those Rythmik plate amps, and crank the bass volume up to the same level as the midrange. Pushing the bass drivers towards their limit.

This OB experience sure has been a bumpy ride.

And it's starting to get more expensive than I wished for.

Graham Maynard · « **Reply #136 on:** 23 Jul 2008, 10:35 am »

Hi painkiller.

If you mount the Alphas on a baffle their basket ringing should mostly disappear.

Also shorting the Alpha tags with a length of wire will be like connecting up to a SS amplifier.

When you tap the cone of a baffle mounted and SS amplifier connected Alpha it will sound very different to when you hold it by its magnet.

Maybe a plate amp with EQ, crossover and phase controls is just what you need for the Alphas, but the high sensitivity of the Superboys will likely still be hard for these drivers to work well together.

Cheers .......... Graham.

ttan98 · « **Reply #137 on:** 23 Jul 2008, 02:25 pm »

Painkiller,

Don't get me wrong, this post is not trying to entice you to spend more money, matching drivers is EASY using active x-over like DCX2496 which is about $250(new) on Ebay.

I like my DCX2496, once I like the matching drivers and speaker configuration I will build passive x-over and still drive each driver separately using different amps, biamp or tri-amp if necessary. eg dialling up x-over and driver matching takes less than 1min. So far I built about 4-5 speaker configurations using different drivers combinations. Study speaker configurations is fun

Passive x-over is too fiddly and time consuming making x-over right and worse still spending too much on each component. If I have many systems I would have spent hundreds if not thousands on just passive components.

Cheers, just an opinion.

scorpion · « **Reply #138 on:** 23 Jul 2008, 09:37 pm »

Painkiller,

Could you give us conditions of your Superboy measurements. Distance, on/off axis, mic height ?
Otherwise a bit difficult to analyze.

And Painkiller, I think you are fumbling a bit in despair. Actually two Alpha15s in parallel mounted above each other centrally on a 40" (1M) W and 32" (80 cm) H baffle (could include wings) will be about 103 dB/W efficient from 40 Hz to 200 Hz. Crossover Linkwitz-Riley 12 db/oct at 200 LP will exactly match next speaker with a 300 Hz HP. Invest 100 NOK in MJK's MathCad models: http://www.quarter-wave.com/ and read his OB papers. Then you can start some serious OB design.

Regarding the Alpha15 I don't think you can complain on its build quality. It is among the sturdiest steelchassies basses I have seen and there are ways to tame resonances, if there.

/Erling

painkiller · « **Reply #139 on:** 24 Jul 2008, 10:37 am »

Quote from: scorpion on 23 Jul 2008, 09:37 pm

Could you give us conditions of your Superboy measurements. Distance, on/off axis, mic height ?
Otherwise a bit difficult to analyze.

On axis, 1 m distance, 60 cm above floor (carpet). And don't pay attention to the absolute SPL readings, as they are not calibrated.

It's hard to believe that two parallell Alphas would match the Superboys in efficiency. I seriously have to EQ them 25dB to match the SPL of these two drivers.

The Alphas sound much better with a second order crossover. No disturbance in the vocal region, just fat deep bass. They're not as bad as my first impression of them. But if you think these are sturdy drivers, you should see the Superboys. I think you could hit them with a sledgehammer without doing any harm.