[Telstar]

I consider burn-in done.
The shout remained, so it will need to be filtered with a notch.

The next steps will be:
1) Measurements. I made myself a gift and got an used Earthworks M30 mic. I'm going to take drivers, speakers and room measurements very seriously.
2) Correction and XO though a Behringer dcx2496 (modded)
3) Woofers (Beyma SM112N) and other test baffles

I'm going for a vacation now and I wont be thinking about my speakers everyday. But I'll be badder and better when i come back

[chrisby]

see my reply in your parallel thread at DIY Audio,  but perhaps Mike Mardis could comment on the suggestion re driver treatment.  IINM, he may have heard what EnABL & other physical mods can do for this and similar drivers.



edit:

Oops, I see from reading this thread more thoroughly that you may have already damarred the whizzers, and had considered, but balked at the EnABL treatment.  If you look closely at the photo posted by Mike, you'll note that they the treatment applied.

[Telstar]

Oops, I see from reading this thread more thoroughly that you may have already damarred the whizzers, and had considered, but balked at the EnABL treatment.  If you look closely at the photo posted by Mike, you'll note that they the treatment applied.

I will dammar the whizzer. I ordered from my art shop 100g of raw dammar gum that i will dissolve and prepare myself.
But i do not have the time to do the full enable treatment. It will be more cost-savvy for me to buy more expensive drivers

[chrisby]

Oops, I see from reading this thread more thoroughly that you may have already damarred the whizzers, and had considered, but balked at the EnABL treatment.  If you look closely at the photo posted by Mike, you'll note that they the treatment applied.

I will dammar the whizzer. I ordered from my art shop 100g of raw dammar gum that i will dissolve and prepare myself.
But i do not have the time to do the full enable treatment. It will be more cost-savvy for me to buy more expensive drivers

IMHO that's not an absolute guarantee, but it sounds like you've already got a firm game plan sketched out -  so have a great vacation, and have fun with the audio project when you return

[Telstar]

Back from short holidays and before going soon to a business trip, it's time for an update.

1) The shout has been tamed with digital EQ, of about 6db. I'm not completely satisfied with the sound, but I'm still on paper baffles (grr me wants to kill the carpenter) and yet the overall sound became more pleasant than my Linns, which are going for sale.

I have been suggested an analog notch filter by Bert, which translates to about -3db at 3k. i'm using about 9db of digital attenuation. I will try it later maybe. At the same time, i also put a low shelf at 100hz. This improved the clarity of the sound and i'm sure it reduced distortion. The poor Hemps with only 1,9mm Xmax* distorts a LOT in the lower regions, which compromises all response. Icing on the cake I boosted from 100 to 200hz to compensate the baffle rolloff.

2) The woofers, a pair of Beyma SM112N have been ordered yesterday and will be shipped tomorrow.

3) The enclosures are MIA due to busy carpenter. I'll see what I can do to burn the woofers in.

4) The XTZ Sub Amp 1 has also been ordered from the very nice italian distributor. Thanks to the help from Rikard of XTZ, the bass boost frequency (7,5db) will be changed to 30hz, replacing a resistance and a cap. This should suit most of my needs.

5) A MSB multichannel volume control will be used as master volume control and my laziness will be preserved thanks to its remote.

[* Yes, yes I have been told that several times, but I replied that i would have tried that, just not passively, which is what i have done]

[Telstar]

Here are the schemes and the simulation (for the FR) of the design v2 of my test baffles, with measures.
They will be in 18mm plywood. There will be wings for the woofers, with composite panels to allow me to try (and measure) the following configurations:

1. front woofer, wing L 33cm, wing R 14cm
2. front woofer, wing L 14cm, wing R 14cm
3. front woofer, wing L 33cm, wing R 28cm

4. side woofer (external), wing front 33cm (this is the front baffle, that u see in the picture), wing back 14cm
5. side woofer (external), wing front 33cm, wing back 28cm

6. side woofer (internal), wing front 33cm (this is the front baffle, that u see in the picture), wing back 14cm
7. side woofer (internal), wing front 33cm, wing back 28cm

I dont think that firing the woofers in the center of the scene is the best idea. I havent seen it realized anywhere. But for the sake of curiosity I will try it.
I may not try all seven setups, if one appears particularly bad, making the wings shorter or longer wont change much - the numbers are small.

Thanks to Rudolf's help, I decifrated MJK formula to calcolate the U-frame resonance. I dont have a top panel, but with the shorter wings i can also lie over the short panel and see if imroves things. My guts tells me that I'm better off a top panel for the u-frame, so I dint order those panels.
Because of this air, the resonance will be very weak probably to the point that I wont need to damp or equalize at all.

The crossover point is estimated at 200hz. It is obvious that up to 300hz the FR drivers will need some boost and i'll do that in digital.

Another thing about woofers is that I'm going to get a couple of absorbing panels to put on the back walls from 0 to 60cm. Because they sell a box of 8 panels and I need only two, I'm looking for a group buy.
http://www.vicoustic.com/produtoInfo.asp?Id=39
This product has very good specs and should fix the fact that the back walls are only 50-60cm behind the woofers.
If not I still have the the ripole card to play

[ttan98]

After listening for a while you may want to add another woofer to make it dual woofer, then the speaker pair will last you for some time. That is my experience.

Cheers, happy listening.

[Telstar]

After listening for a while you may want to add another woofer to make it dual woofer, then the speaker pair will last you for some time. That is my experience.

Cheers, happy listening.

We'll see
In my room and at apartment-level SPL I think one can be enough... that was my estimation... but they are neat!
The courier rang half an hour ago and they are playing right now on the floor, in full-range and they SOUND PRETTY GOOD! I dont hear any MF ripple.
Later on, I will set them up for intensive burn-in with pink noise. Now i was just to curious to hear them sing.
I'm sure I did a good choice with Beyma If i'll add another pair, it'll be Beyma as well.

On tuesday-Wednesday will be ready the test baffles in the above schemes.

[Telstar]

***
First impressions

As rugged as they may be brand new on the floor, the bass is already punchy, and willing all voice range is within them with not clear ringing. Stellar price/performance ratio imo. Not that I have experience with many woofers, but I remember for instance the 2 10" pairs used in the Orions and I believe these are better.

They are being powered by the main posts of my Class? which has all the juice they need. Playing at moderate SPL for today. I planned to do the opposite phase trick and use pink noise, but instead i'm enjoying them playing! So they'll get music all the day and by the time i'll get the baffles, they should be burned in.

Another good thing is that my SMALL spades fit into the hole for wire/banana on the posts so I didn thave to buy adapters or new cables. I plan to use silver cables which I will build following a design that I have in mind, but now i dont have the time nor the money.

From now and then I'm adding also the FRs to give some more hours, but the frequence overlap without XO on the woofers is way too much. To make it acceptable, i'm using about -6db in the midrange and +6 at LF and +3 at HF. There is a slight sound pressure unbalance that favours the woofers about 2db (no big deal).

I can imagine that things will sound really good when everything will be setup. Unless the XTZ subamp is a piece of crap, but i doubt that
Next week will be busy but very interesting.


Pictures (they are now more further apart and closer to the baffles):

[panomaniac]

Looks like it's coming along quite well - bravo!
The Hemp FR8 makes a very nice extended midrange for OB - I sure miss mine. (They do well in a TL type box, too).

I agree with your EQ.  The driver does shout if you don't tame it.  But it's not hard to fix.  A little active EQ or just a simple coil in series will do it.  I guess I was the 1st to EnABL these drivers.  It did clear up some distortion.

The Beyma is very pretty.  If it sounds as good, you'll be happy!
  Just as a reminder, he is my old hemp OB rig. Selenium 15s on the bottom.  Pine and bamboo baffles.

[Telstar]

The Beyma is very pretty.  If it sounds as good, you'll be happy!

No, they sound better than they look

Just as a reminder, he is my old hemp OB rig. Selenium 15s on the bottom.  Pine and bamboo baffles.

Cool. I'm just talking with my carpenter about the definitive baffles material. I want bamboo with some sort of sandwitch for at least 6cm total depth.
Why did you choose pine?
I was thinking bamboo-mdf- and then another bamboo layer or birch perhaps.

Other question: in your hemp baffles, the offset is to make the drivers closer to the center, i have frickin space constraings and i'm going to have them on the sides (its just 2 cm off-center, though, almost nothing but enough to smooth the curve). What's your motivation?

[panomaniac]

I choose pine because it was cheap, easy and thick.  The bamboo is only 1/4" thick on these, so is only to "make pretty."  I have used 3/4" bamboo ply, it's very nice but very $$. 6cm depth?  That's a lot.  I hope you don't get problems with resonances in the driver holes.

As for driver placement, I did some sims in "The Edge" software.  Never found a perfect placement, so did the best i could.  FR8s were more or less at ear level, 15s near the floor for some bass boost.  Wings asymetric.  I did run them with the FR drivers inside and outside. Both worked, dont' know which was better - just diffrent.

[Telstar]

I choose pine because it was cheap, easy and thick.  The bamboo is only 1/4" thick on these, so is only to "make pretty."  I have used 3/4" bamboo ply, it's very nice but very $$. 6cm depth?  That's a lot.

4,5cm thickness bamboo plywood is the most that my carpenter has found in italy. No idea about price yet, but will be expensive They hare hard pressed. Then i'm planning a sheet of mdf of about 1cm and a final layer of another wood about 2cm, with good resonance properties. I'll choose between birch, spruce and mahogany.
That is only for the definitive baffles. Before will probably be a v3 test baffles or a different FR (cant get the Mangers out of my head, so i'm going to listen to them next week).

This design that Bert posted on his forums, along with a notch filter suitable for my Hemps, is VERY nice looking. I'm thinking to pair that with Ripole wofers. It would be WAF approved for sure. We'll see...

I hope you don't get problems with resonances in the driver holes.

Can you explain this?

As for driver placement, I did some sims in "The Edge" software.  Never found a perfect placement, so did the best i could.  FR8s were more or less at ear level, 15s near the floor for some bass boost.  Wings asymetric.  I did run them with the FR drivers inside and outside. Both worked, dont' know which was better - just diffrent.

Yes, I had similar problems, I ran dozens of simulations. Everytime i changed ONE cm of baffle width everything had to be redone.
The only curve that came as smooth as the one with offset drivers was the one of the chosen trapez-type shape. I think i posted the picture up. BOTH obliques cuts are needed to smooth it. But My carpenter charge me only 10? to do the cuts, so they are VERY WELCOME

[Telstar]

Lets start from the facts.
After two weeks during which I tinted the several little pieces of plywood, sanded and finally lacquered, 3 days ago I finally mounted the drivers in the baffles v2.

The panels were made exactly as designed by a very capable carpenter, which is now "my carpenter". As a first I put the longer wings, which are 33cm long, exactly as the front. Two of them (visible on the left speaker) have holes, which are filled by discs, taped in the inside. They were made this way to allow me to mount the woofers on the side.

But after I powered the speakers, the bass was so overwhelming and "right" that I'm not going to try a side-mounting. The issues of the back wall are way less than i have been told. Distance is only 70cm and CANNOT be more due to room furniture and listening position (center sear of a couch, at 1,9m).

At the same time, I cleared all the space behind the speakers. The Linns are in the right corner, which is a bit resonant area, and I think they help a bit like a bass trap.
Anyway measurements are still on the way: I tuned the speakers ALL by ear.
Below you see the picture of the current setup.

So, how they sound? Did the baffles v2 improved the Hemps?
You bet!

Let's start from the fullrange. The distortion is way lower. The ones who said that the pressed cardboard was culprit of most of it was right. Also, the EQ that i based on some measurements posted by a guy on diyaudio, NOW sounds right and they seem to fix most of the inherent non-linearities of the hemps.
I'm still considering finding better drivers for the task, but I dont feel the urge to anymore.

Now, the most amazing surprise. The bass. FANTASTIC. Much, much more that I expected. I started with the longer wings. Maybe I shouldnt have. I had to immediately reduce 8db on all the range (20-300hz) covered by the Beymas. Then, I also had to reduce the lowshelf @20hz of 10db to 8db. Whoever said that bass doesnt work in open baffle is an idiot.
I'm sure that my room compensate for most of the OB rolloff from 60 to 150hz and beyond. With the XTZ amp, i will probably not need any bass boost via software. Or i'll use just the latter, whichever sounds best.
Drivers on the floor play much softer, it is obvious, but the change has been dramatic also on the quality, the fullness. You need to look beyond the speakers to notice that there is no (closed) box. The bass is tight, fast, tuneful, as you would expect from the best speakers you can find.

Lastly, the blend between woofers and FR also improved from the positioning. The XO point remained at 300hz and I do not really feel a solution of continuity. A friend of mine told me that after I measure many things will change and the sound will improve. Curious to see which mistakes my ears have done

Next steps:
1) Measure everything
2) Improve the XO (try other stuff such as acourate) and DSP
3) Treat the back wall

For now, I'm just enjoying the music. For the first time in a LONG time, I can listen without earplugs.

[Rudolf]

Hi Telstar,

I like it when people see (better: hear) real progress!
To me it always has been difficult to judge the potential of a system from the quality of separated components or to mentally mask out inferior parts. It only fell together when everything was integrated on a comparable quality level. Looks like you have reached that point.

I'm happy that you like the bass level and performance. You should have fun doing the minor changes and improvements that will give you even more satisfaction.
Your baffles blend so well with the floor - it would be a pity to discard them for other ones anytime soon.

Rudolf

[Telstar]

Hi Telstar,

I like it when people see (better: hear) real progress!
To me it always has been difficult to judge the potential of a system from the quality of separated components or to mentally mask out inferior parts. It only fell together when everything was integrated on a comparable quality level. Looks like you have reached that point.

Yes, I think to be able to spot the bottleneck, or to guess it.

I'm happy that you like the bass level and performance.

There's a slight resonance(s) not sure if due to the wings or just to my crazy room.

You should have fun doing the minor changes and improvements that will give you even more satisfaction.

Measuring will be fun. But replacing/adding drivers is not. I dont really feel like unmounting and drilling and mounting everything again

Your baffles blend so well with the floor - it would be a pity to discard them for other ones anytime soon.

Rudolf

I like em too. We have all walnut furniture. The walnut color tint sucked so I mixed cherry and teak. I hope they look good enough for my SO.

I have another update, not directly related to my speakers. Yesterday, I went to listen to a very interesting setup: all CEC electronics (good, except the DAC) and the surpsising Heil AMT Syrinx (Precide.ch, not the ones from ESS).
These use DIFFERENT AMTs than ESS, which havent improved since the old times. I have to admit that my curiosity about these sperkers brought me there.

I have never listened to ribbons that I liked, so I was biased. I was wrong. These are good ribbons. And I liked them. The "proof of the 9" (as we say in italy) was the track "My confession" (Josh Groban, Closer, WEA), among my reference discs.
For the first time, I heard it right. This is no small feat. A friend that was with my said "there is no defect in this recording". Yeah, listen it with your own system, even with headphones. It will sound wrong. On the Syrinx it was listeneable, no pleasant. The HF harmonics where right were they belonged. And the very strange instrument used to add rythm didn not sound like a "ch-ch-ch", but like something that blended with the music. I dont think it's only a matter of extension, it's also transient speed, and very low distortion. Why it didnt sound right on the Manger MSWs? Hell if I know.
They go up "only" to 23k, which i think it's enough. I didnt feel anything missing or too much (like with cheap ribbons) up there. I didnt feel any distortion.
Defects? None, besides the low efficiency.
If only that system has a state-of-the-art dac to get rid of the digitus...

The type "aulos" swiss-made AMTs are not normally available for sale and as replacement parts they are expensive (over 400 eur each) and unlike ESS Heils are not efficient (89db). As you can see from the Syrinx picture, they are very small and completely dipolar.

Forgot the picture:

[Telstar]

The subject means that basically the Hempatics project finishes here. I dont see margins of improvements that wont require the replacement of the Hemp drivers themselves, making the name void.
I'll make a new thread when will be the time.

I can sum up the balance, though.

Plus:
+Very low cost
+Sound quality like commercial speakers of 5-10 times more the cost
+Excellent bass from my POV
+Better transparency than ANY speaker I have ever heard, not considering price. (this thanks to direct connection to amps and software crossovers)
+Easy, seamless integration between the Beymas and the Hemps, both drivers are recommended, knowing their characteristics.

Minus:
-Fullrange drivers not particularly undistorted and with an annoying energy storage around 3k which hasnt been easy to tame
-Limits in reproduction of high harmonics
-Low SPL in the very low bass (under 60hz)
-Air/ambience could be improved with speakers with higher freq extension
-Wings size a bit too much that creates a little resonance around 250hz (can be fixed cutting the wings).

The future steps will be replacing the FR with unconventional widerange midrange transducers (top secret for the moment) + Heil AMT (Mundorf or Precide models) and the addition of a pair of closed-box subwoofers with peerless XXLS 10" to augment the very low bass (up to 50-60hz).
And obviously new baffles, with better finish, smaller wings and narrower on the top!

The reason for delays is that I'm waiting to get a state of the art DAC that will help me evaluate the new speakers that will come. I can only say that the name will be crazy.

Stay tuned.