The Hempatics OB

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Hempatics is the name that I gave to my babies :)

After months of research and hundreds of kb of electronic ink spent on forums and emails, the fullrangers have been chosen and the Hempatics are born.

Day 1
An unexpected ring in the late morning brought the quite unexpected news that my package arrived from the Netherlands in just 4 days. I had hoped to get them before the end of this week, but I wasn't counting on it.

If now you are suspecting the reason of the name, it's now revealed. The FR are a pair of Hemp Acoustics FR8C, production date 6/2007.

The package:
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The invoice:
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The little boxes:
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As you can see, one of the baskets came through the box, but no damage has incurred:
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Close-up of the corner where the sourround is slightly scratched (hard to notice):
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The babies:
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They are sooo cute! And little.

The temporary baffles, made from the cardboard of the inside of the box. It makes for a very handy floor mounting.
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Here are the drivers connected with bare DNM wire.
Left one:
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and Right one:
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Now, its 3 hours that they are burning in, hooked to the ovenly* Firstwatt F3.
They sound, no issues whatsoever. Quieter than I expected, but they are already pleasant.
I will do a first impression listening test tomorrow morning at higher volumes.

[* hope you get the joke, if not oven/heaven.]
 
Day 2 - First impressions

Day 2

Very first impressions ad normal SPL, after about 5h at normal SPL + 7h at very low yesterday.

The rest of the chain in this moment is composed of:
Teac vrds10se (with tent clock)>Muse Model Two>Classè CAP-100 (only as pre or as integrated)>Firstwatt F3. Comparison speakers are my old Linn AV5140. Obviously is my intention to besten them in all parameters.
For simplicity of switching (I do AB very often, the Classé mutes its own amp stage when used this way, which is very handy), the Linns are connected to the power amp stage of the Classé, while the Hemps are connected to the F3. In both cases the preamp is the (very good IMO) preamp stage of the CAP-100. Also note that the F3 is NOT able to drive the crossover of the Linns, and was tested only on the midrange (filtered).

Negs:
First, it definitely needs a bass augmenter. I will measure with simple test tones how low it goes, but it lacks the punch. This is the most apparent deficiency.

Second, air is lacking. This is more disappointing. The F3 is able to deliver SOTA "class A" airy sound and I want it all. I hope finishing the burn-in will be enough, otherwise a supertweeter will be needed.
My hearing is VERY good, I can clearly listen to 17k tones and I'm also sensitive to HF distortion.

Third, Vocals are already of matching quality, plus the tubelike quality of the F3.
It is not truly a merit of the Hemp, but just of the F3, which has in the past be connected to only the midrange driver of my Linns, exibiting tubelike qualities while keeping distortion low (@4 ohms).

Fourth, HF have some harshness, but it is already LESS than yesterday, so I think it will be gone by the end of burn-in. If not completley, I'll use dammar on the voice coil and whizzer.

Positives:
None, so far.
The only advantage being represented by the single driver doing the job of a midbass, midrange and tweeter.

Ok, I can say that the timbre is accurate, and that with some songs I can get already a more "you are there" feeling. But not enough, not even close to my goals.

I'm sure that the source is the bottleneck, and I do plan to replace the DAC and a computer source, but before that I need to be sure that the FR are of sufficiently good quality for my expectations.

Note that the Hemps are playing on the floor, with about 30° inclination upwards, and 30cm to the back wall. I'm not sure how much this influence my impressions. Anyway, I will start building pressed cardboard baffles next week.
 
Scottmoose said:
Yes, sensitivity on the Hemps is a few db less than the old published claims, which really were trying it on. Still, they'll always sound quiet outside a box or baffle, so that won't help.

My guess is that is roughly 94 db vs the 96.5 declared.
When I put them in a baffle it will rise?

I have no SPL issues using an active preamp (and the Muse has a LOW output, i believe to be 1,5V)
 
Telstar said:
When I put them in a baffle it will rise?

No, driver efficiency is driver efficiency. However, you will have more gain on the bottom end given that you've nothing to prevent the front - rear outputs cancelling by just listening to the raw units. As such, I wouldn't try to draw any real impressions on their sound quality at present- it'll be all but valueless. Bit like trying to assess a Ferrari engine in a Jeep. Although come to think of it, given that (as a general rule) I loath Ferrari, that might not be such a good analogy... :D
 
Wise. A small supertweeter cut in above ~8 - 10KHz as suggested might be worth your pursuing if that's the sort of sound you like. One of the main advantages of FR drivers is not necessarily so much that they are full range (nothing is, although they often cover enough to satisfy many people depending on preferences & material played), but that you can push any XO you might want outside our critical hearing BW, or mostly.
 
advantages of FRs

Scottmoose said:
Wise. A small supertweeter cut in above ~8 - 10KHz as suggested might be worth your pursuing if that's the sort of sound you like.

It might not be needed :)
Sound is already improving. We'll see at the end of burn-in with the first measurements in the test baffles.

Originally posted by Scottmoose
One of the main advantages of FR drivers is not necessarily so much that they are full range (nothing is, although they often cover enough to satisfy many people depending on preferences & material played), but that you can push any XO you might want outside our critical hearing BW, or mostly.

I agree.
That and not having to put any filter between the amplifier and the music.
 
Scottmoose said:
Then you're begging for trouble on a baffle, as I've mentioned many times before, if you don't protect it from the LF. The distortion will ripple right up through the midband (200Hz - 4KHz per Bell Labs definition of the telephone band, + 1 octave either side in an ideal world).

That depends only on the SPL and on the driver characteristics.
With 90dB average I do not think i'm pushing my hemp a little bit.
 
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