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Old 16th March 2012, 10:18 PM   #1
Klimon is offline Klimon  Belgium
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Arrow Alpha 15 enabl

Knowing some of you were there before me: looking for some pointers in treating Alpha 15 for open baffle duty (MJK-style, crossed 2nd order at 100-150hz).

- Pre-treatment with ModPodge (how many coats, reverse side also?)
- Enabl patterns (pics most welcome as for placement of eventual mid rings!!!)
- MicroGloss (how many coats?)
- Dustcap treatment?

FWIW frame damping with ductseal on the outside of legs + around magnet // inner frame surfaces lined with acoustic foam (hoping it won’t rob too much off the backwave)

Muchas gracias!!
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Old 16th March 2012, 11:37 PM   #2
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Hmmmmm...

While there are reports of eNabl really helping a driver, I can't see it being of any benefit for a bass driver: it's operating in its pistonic region, so cone break-up etc is a non-issue.

Frame damping would be a good idea, as would breaking up reflections through the cone from the basket.
If you want to measure your progress, put a LF square wave through the speaker, add a low-cut, so you only get clicks.
Put a mic near the cone, watch on an oscilloscope for reflections: using s=d/t, you can figure out roughly which surface leads to which reflection, then add damping accordingly.

I've seen this work very well for a pair of wide-band 12" drivers.

Chris
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Old 17th March 2012, 12:05 AM   #3
sreten is offline sreten  United Kingdom
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Hi,

None of what you suggest will make any difference in the range
suggested other than the effect of adding some cone mass,
and there are lots of ways of doing that.

An electrical trap filter to suppress the +10dB peak at 2KHz
is a start point if you want change the driver behaviour.

rgds ,sreten.
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Old 17th March 2012, 12:15 AM   #4
Klimon is offline Klimon  Belgium
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Quote:
Originally Posted by chris661 View Post
Hmmmmm...

While there are reports of eNabl really helping a driver, I can't see it being of any benefit for a bass driver: it's operating in its pistonic region, so cone break-up etc is a non-issue.

Frame damping would be a good idea, as would breaking up reflections through the cone from the basket.
If you want to measure your progress, put a LF square wave through the speaker, add a low-cut, so you only get clicks.
Put a mic near the cone, watch on an oscilloscope for reflections: using s=d/t, you can figure out roughly which surface leads to which rction, then add damping accordingly.

I've seen this work very well for a pair of wide-band 12" drivers.

Chris
Thanks, but the straigthforward way for me would be to get a testimony of how other people (found a quote by Dave saying Chris would do this on some alphas) proceeded; also found several testimonies of the usual suspects quoting great results of coating/enabl on woofers... No measuring equipment nor time to reinvent the wheel, looking more for a manual by people who already did the experimenting work on these particular drivers. I think quite a number of forum members might benefit equally from such info as these are about the 'generic' OB woofers.

Best,

Simon
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Old 17th March 2012, 12:22 AM   #5
sreten is offline sreten  United Kingdom
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Hi.

If you want to believe in UnABL(e) thats up to you, I don't care.

Pretty dots will do absolutely nothing other than looking like they do.
The UnABL(e) subjective thread is full of fundamentally impossible
"testimonials" as to its effects and a wise man is always sensible.

If you want to think any of the UnABL(e) claims in the subjective
thread are true, consider why that thread exists in the first place.

rgds, sreten.

None of the mods you suggest will change a driver x/o
at 100Hz to 150Hz much, the mods seem pointless.
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Last edited by sreten; 17th March 2012 at 12:48 AM.
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Old 17th March 2012, 12:43 AM   #6
Klimon is offline Klimon  Belgium
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Quote:
Originally Posted by sreten View Post
Hi.

If you want to believe in UnABL(e) thats up to you, I don't care.
Much appreciated! Hopefully others will follow your wise example and let this thread evolve in a constructive manner.

Simon
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Old 17th March 2012, 02:22 AM   #7
sreten is offline sreten  United Kingdom
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Quote:
Originally Posted by Klimon View Post
Much appreciated! Hopefully others will follow your wise
example and let this thread evolve in a constructive manner.
Simon
Hi,

I can live with sarcasm. Fair enough you want to think EnABling
a bass driver is a good idea along with modge podging it etc...

Added mass changes it the most and probably the best stuff
for this is bitumastic car body underseal / antichip spray can.
But who cares about that, that is not being constructive ....

What you want to do is construct is a faith / belief paradigm.
In other words evolving nonsense. Your welcome to it.

rgds, sreten.
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Last edited by sreten; 17th March 2012 at 02:31 AM.
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Old 17th March 2012, 03:21 AM   #8
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Someone told me enable is made from a mixture of toothpaste... Could that be true?

The benefits of enabling a driver could be weighed against purchasing a better driver.

I have the Alpha 15 and a Jamo close out from PE whose specs and sims less suit OB yet it sounds more musically satisfying to me. Having said that, the Alpha 15 is excellent in H-frames as is.

For bass duty, the amp you choose will have a great impact on the sound of the Alpha. I'd consider this before enable.

This is DIY and we can do whatever we choose, but I would not enable an Alpha 15.
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Old 17th March 2012, 02:26 PM   #9
Klimon is offline Klimon  Belgium
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Quote:
Originally Posted by Godzilla View Post
For bass duty, the amp you choose will have a great impact on the sound of the Alpha. I'd consider this before enable.
Yup, ta3020 based amp into parallelled pair of alphas / channel. Tubes on top (well ofcourse).

Simon

Last edited by Klimon; 17th March 2012 at 02:32 PM.
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Old 17th March 2012, 06:43 PM   #10
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In that case I would choose the Betas.

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