My Beyma story...
First , if moderators think that my topic needs new thread - feel free to move it wherever you think is convinient - sorry I'm newbie here
So to get started...
Searching and learning through the numerous posts DIY audio bug catch me again after 7 years of idling, and I finally decided to make back loaded horn aka "Das Viech" for my main speakers - I've read so many nice things about horns that I had to made them - so Beymas are my first horns and first fullrangers that I've made - they are very cheap so no financial problems for me
Search for Beyma distributor here in Croatia was useless so I contected few suppliers in Germany and just when I almost ordered 2 drivers from Spectrum Audio, I've got mail from Mr. Jerzy Purtak (Beyma distributor for Central & Eastern Europe) and told me that he is willing to bring me these two drivers as he is going on vacation to Croatia - hey, I couldn't beleive that such good people still exist
To cut a long story, I've got the drivers in 7th month this year, and mount each in 1m tall and 25cm wide piece of particle board - some kind of testing stands for speakers.
(They can be probably called "very loussy and extremely narrow open baffle".
)
But even with such bad mounting ideas I noticed that they sound very nice - extreme high's were missing but midrange was very warm and pleasent, vocals are far more natural then can be expected for 20 Euro driver and I can now see why open baffles have incredible soundstage .
After listening them for last 5 months and more then 100 hours - I decided to make boxes as I couldn't stand lack of bass no more - I must say that Cyburgs plans are very well documented and very straightforward...
I decided to use 19m MDF for my project - after 7 looong days of MDF dust torture boxes were done and I finally connected them to my simple sistemld Marantz CD 38 player + my DIY chip amp (TDA 7294 based).
First listening impressions:
When I connected them it was late at night (2 PM !) but I just couldn't resist - I have to hear them !
But on such low volumes I hear nothing worth mentioning - bass was there and was slightly boomy but I thought that's nothing serious and went to sleep...
But next day was very interesting...
I've get up early in the morning so I can start listening - I listen 3 hours constantly changing all genres : from electronic music (Mouse on mars) , rock (Simple Minds), pop to different audipohile compilations with jazz,blues, etc.
First impression after listening cca. 10 cd's on moderate levels - where is that bass???
Horn bass is always described as ".. Fast , clean and strong" - no way , bass is sooo boomy, with strange midbass coloration and most important there is in fact lack of bass ?!?!
OK, I am not car bass fanatic and I know that my room is way too small for some serious bass response with horns (4mx4m) , but my last floorstanders (also cheap DIY - 2 way, bas reflex with 16cm mid bass driver) would "kill" this 2 funny looking Beyma's in terms of definition and especially depth in same room , not to mention they are smaller then horns - mmmm, things are not looking any good ... :-(
What could be wrong - I made boxes exactly to the plans, all joints and drivers are very well sealed , I even tried tone controls that I almost never needed before and still nothing - in front of me are two large , ugly monsters that even play music loussy
Is there any hope ?
As last resort I remember that I read somewhere that Beyma's need to play "...loud, REALLY loud" -hmm I've play my CD's loud but not REALLY loud when I was testing them - hmmm, maybe there is something in that sentence...pro driver with hard supension....could that be the problem ?
I twisted volume knob 1/4 turn , waited - and my jaws dropped - same song, just different volume - incredible wall of sound came from that speakers - bass hits you so hard that instantly reminds me of standing in front of PA system on concert - strong - powerful - clean .
For example : drums on Dead Can Dance ("Spiritchaser" album) feels so right, so live - nothing I've ever experienced with ordinary bass reflex speakers.
Beyma's suddenly completely changed its character - in fact like somebody turn on loudness effect - bass increases, mid coloration decreases - I know it's hard to beleive, but to me they are sounding more clean on high volumes.
I'm still excited because I can't beleive that such dynamic was possible in my room before - probably my neighbours are excited too
But already I see some drawbacks - as Cyburg mentioned there is no useful output under 50-60 Hz - I've done sweep test just to be sure.
Electronic music can't be played very well if there is much material under 50 Hz.
Also very complex passages sound "muddy" and not very good.
That' all for now , sorry for long post but I had to !
First , if moderators think that my topic needs new thread - feel free to move it wherever you think is convinient - sorry I'm newbie here
So to get started...
Searching and learning through the numerous posts DIY audio bug catch me again after 7 years of idling, and I finally decided to make back loaded horn aka "Das Viech" for my main speakers - I've read so many nice things about horns that I had to made them - so Beymas are my first horns and first fullrangers that I've made - they are very cheap so no financial problems for me
Search for Beyma distributor here in Croatia was useless so I contected few suppliers in Germany and just when I almost ordered 2 drivers from Spectrum Audio, I've got mail from Mr. Jerzy Purtak (Beyma distributor for Central & Eastern Europe) and told me that he is willing to bring me these two drivers as he is going on vacation to Croatia - hey, I couldn't beleive that such good people still exist
To cut a long story, I've got the drivers in 7th month this year, and mount each in 1m tall and 25cm wide piece of particle board - some kind of testing stands for speakers.
(They can be probably called "very loussy and extremely narrow open baffle".
)But even with such bad mounting ideas I noticed that they sound very nice - extreme high's were missing but midrange was very warm and pleasent, vocals are far more natural then can be expected for 20 Euro driver and I can now see why open baffles have incredible soundstage .
After listening them for last 5 months and more then 100 hours - I decided to make boxes as I couldn't stand lack of bass no more - I must say that Cyburgs plans are very well documented and very straightforward...
I decided to use 19m MDF for my project - after 7 looong days of MDF dust torture boxes were done and I finally connected them to my simple sistem
ld Marantz CD 38 player + my DIY chip amp (TDA 7294 based).First listening impressions:
When I connected them it was late at night (2 PM !) but I just couldn't resist - I have to hear them !
But on such low volumes I hear nothing worth mentioning - bass was there and was slightly boomy but I thought that's nothing serious and went to sleep...
But next day was very interesting...
I've get up early in the morning so I can start listening - I listen 3 hours constantly changing all genres : from electronic music (Mouse on mars) , rock (Simple Minds), pop to different audipohile compilations with jazz,blues, etc.
First impression after listening cca. 10 cd's on moderate levels - where is that bass???
Horn bass is always described as ".. Fast , clean and strong" - no way , bass is sooo boomy, with strange midbass coloration and most important there is in fact lack of bass ?!?!
OK, I am not car bass fanatic and I know that my room is way too small for some serious bass response with horns (4mx4m) , but my last floorstanders (also cheap DIY - 2 way, bas reflex with 16cm mid bass driver) would "kill" this 2 funny looking Beyma's in terms of definition and especially depth in same room , not to mention they are smaller then horns - mmmm, things are not looking any good ... :-(
What could be wrong - I made boxes exactly to the plans, all joints and drivers are very well sealed , I even tried tone controls that I almost never needed before and still nothing - in front of me are two large , ugly monsters that even play music loussy
Is there any hope ?As last resort I remember that I read somewhere that Beyma's need to play "...loud, REALLY loud" -hmm I've play my CD's loud but not REALLY loud when I was testing them - hmmm, maybe there is something in that sentence...pro driver with hard supension....could that be the problem ?
I twisted volume knob 1/4 turn , waited - and my jaws dropped - same song, just different volume - incredible wall of sound came from that speakers - bass hits you so hard that instantly reminds me of standing in front of PA system on concert - strong - powerful - clean .
For example : drums on Dead Can Dance ("Spiritchaser" album) feels so right, so live - nothing I've ever experienced with ordinary bass reflex speakers.
Beyma's suddenly completely changed its character - in fact like somebody turn on loudness effect - bass increases, mid coloration decreases - I know it's hard to beleive, but to me they are sounding more clean on high volumes.
I'm still excited because I can't beleive that such dynamic was possible in my room before - probably my neighbours are excited too
But already I see some drawbacks - as Cyburg mentioned there is no useful output under 50-60 Hz - I've done sweep test just to be sure.
Electronic music can't be played very well if there is much material under 50 Hz.
Also very complex passages sound "muddy" and not very good.
That' all for now , sorry for long post but I had to !
hello all, just moving to spain i figured i would give this design a try for my first speaker build. if i'm not satisfied with the beyma drivers are there any fostex drivers that would work as a drop in replacement? also, beyma makes another, more expensive 8" driver that i believe is full range. has anyone tried this one?
gracias!
gracias!
Hi,
I am very happy to have found this thread. I bought the Beyma 8AG/N
driver about a month ago. Price was 21 euros. I did know nothing about this driver, my first intention was to buy Fostex but i had to order them from Germany and it was boresome...it only took me 30m to get the beyma driver from a speaker store here in Madrid.
I can't read frequency response charts. These drivers are out of Beyma's professional line. They are designed for public addressing etc.
But they are cheap so i took the risk.
First impression was bad...but out of the box...with no cabinet.
I thought to myself i have lost 21 euros.
The driver was forgotten.
Then, one day i made changes in my DIY SET amp. The amp sounded great now. Then i thought let's try the Beyma again and i did.
Very nice. It sounds good, i can't believe it...now it needs an enclosure so i'll probably build the Viech.
Thanks Cyburgs for posting your project.
This driver improves with time.
I am very happy to have found this thread. I bought the Beyma 8AG/N
driver about a month ago. Price was 21 euros. I did know nothing about this driver, my first intention was to buy Fostex but i had to order them from Germany and it was boresome...it only took me 30m to get the beyma driver from a speaker store here in Madrid.
I can't read frequency response charts. These drivers are out of Beyma's professional line. They are designed for public addressing etc.
But they are cheap so i took the risk.
First impression was bad...but out of the box...with no cabinet.
I thought to myself i have lost 21 euros.
The driver was forgotten.
Then, one day i made changes in my DIY SET amp. The amp sounded great now. Then i thought let's try the Beyma again and i did.
Very nice. It sounds good, i can't believe it...now it needs an enclosure so i'll probably build the Viech.
Thanks Cyburgs for posting your project.
This driver improves with time.
What a nice stuff!!
Well, Beyma has others Nice Drivers to build Hi-Fi Horns. Wath about it http://www.bmm-electronics.com/Product.asp?Product_ID=3634
Fs 105 Hz produce only fast midis but Real bass i have my doubts ( Take attention !! I've a W-HORN + Selenium WPU1805 the earthquaker in my garage )
Imagine my challenge tryng to find Beymas in Brazil
Anybody knows where I can find them in the UK ?
Well, Beyma has others Nice Drivers to build Hi-Fi Horns. Wath about it http://www.bmm-electronics.com/Product.asp?Product_ID=3634
Fs 105 Hz produce only fast midis but Real bass i have my doubts ( Take attention !! I've a W-HORN + Selenium WPU1805 the earthquaker in my garage )
Imagine my challenge tryng to find Beymas in Brazil
Anybody knows where I can find them in the UK ?
Hi Craftsman
Ever tried this fullrange unit? http://www.eletrosates.com.br/store...=15&codigo_departamento=6&codigo_categoria=11
I haven't, but if I were in Brasil I would do it. I have such a suspicion that it would not be that different than a 21 euro Beyma. Well, Beyma is more expensive, but so are the costs in Europe.
Erik
Ever tried this fullrange unit? http://www.eletrosates.com.br/store...=15&codigo_departamento=6&codigo_categoria=11
I haven't, but if I were in Brasil I would do it. I have such a suspicion that it would not be that different than a 21 euro Beyma. Well, Beyma is more expensive, but so are the costs in Europe.
Erik
Hi Erik,
Thanks for the sugestion. But Qts 1,84 and Pe 15 Wrms is disencourageous. See more details here http://www.bravox.com.br/produtos/fullrange_f8.asp ( a.k.a. 9 euros )
Bravox site mention something about "in-ceiling use with line transformers".
By the Way.... Here's my final choice:
http://www.selenium.com.br/site2004/catalogo/pdf/wooferpw3_8pw3_8pw3-slf_new.pdf
Blended w/ a dome tweeter like Vifa DX25TG-05-04, of course.
Pictures in a former MTM test box design:
Craft
Thanks for the sugestion. But Qts 1,84 and Pe 15 Wrms is disencourageous. See more details here http://www.bravox.com.br/produtos/fullrange_f8.asp ( a.k.a. 9 euros )
Bravox site mention something about "in-ceiling use with line transformers".
By the Way.... Here's my final choice:
http://www.selenium.com.br/site2004/catalogo/pdf/wooferpw3_8pw3_8pw3-slf_new.pdf
Blended w/ a dome tweeter like Vifa DX25TG-05-04, of course.
Pictures in a former MTM test box design:
An externally hosted image should be here but it was not working when we last tested it.
Craft
Dear Scott,
you are right, the Viech is a chamberless horn. I stumbled over them by incident, when trying to simulate a horn for the Beyma 8AG/N, whose parameters are far from optimal for a fullrange horn (Fs around 100, QTS around 1).
I found out that the smaller the chamber gets, the more robust the horn gets against driver influence. All in all the chamberless horn has following properties (im my experience):
- The horn is very robust against driver alternatives, the Fostex FE206E for example works also very well in the Viech enclosure, (although you could go deeper with an optimized horn for this driver). The german DIY-audio magazine Klang&Ton even took a 17cm fullrange driver for the Viech and it worked very well. However, there are limits of course, for example the Visaton B200 doesn't work at all in the Viech.
- Chamberless horns don't have the low-pass function of the chamber, therefore the horn mouth tends to play relatively high. Normally this is a behaviour you wouldn't like, but sometimes this can be very useful to assist a driver with weak lower mids. I constructed a chamberless horn called "Engelstrompete" for Fostex FE126E, which takes the high sensitivity of the mids and treble (about 93dB/W/m) down to the bass region with this trick. Here a post in german with picture, plan and frequency plot (I can make an English version of this post, if anybody is interested):
Engelstrompete FE126E-Horn
- Chamberless horns tend to have smoother bass response, the chamber induces often more ripple in the upper bass region.
- When the driver is strong enough in the lower mids, then the addidional output of the chamberless horn can make the sound boomy. You can influence this area with horn damping, but only to a certain extent, otherwise the deep bass is suffering. Also the horn-foldings help to reduce the output in this area. But with some drivers it just doesn't fit.
- On the other side sometimes you don't have much choice. Some drivers only work in chambered horns, for example Visaton BG20, some work in chambered as well as in chamberless horns, like Fostex FE126E and FE206E and some work only in chamberless horns, like the Beyma 8AG/N.
It was very interesting for me to find out that many of the vintage horns (like Schmacks) are chamberless horns. I suppose that was to enable the horns to be driven with different driver models, maybe.
Nice greetings, Berndt
you are right, the Viech is a chamberless horn. I stumbled over them by incident, when trying to simulate a horn for the Beyma 8AG/N, whose parameters are far from optimal for a fullrange horn (Fs around 100, QTS around 1).
I found out that the smaller the chamber gets, the more robust the horn gets against driver influence. All in all the chamberless horn has following properties (im my experience):
- The horn is very robust against driver alternatives, the Fostex FE206E for example works also very well in the Viech enclosure, (although you could go deeper with an optimized horn for this driver). The german DIY-audio magazine Klang&Ton even took a 17cm fullrange driver for the Viech and it worked very well. However, there are limits of course, for example the Visaton B200 doesn't work at all in the Viech.
- Chamberless horns don't have the low-pass function of the chamber, therefore the horn mouth tends to play relatively high. Normally this is a behaviour you wouldn't like, but sometimes this can be very useful to assist a driver with weak lower mids. I constructed a chamberless horn called "Engelstrompete" for Fostex FE126E, which takes the high sensitivity of the mids and treble (about 93dB/W/m) down to the bass region with this trick. Here a post in german with picture, plan and frequency plot (I can make an English version of this post, if anybody is interested):
Engelstrompete FE126E-Horn
- Chamberless horns tend to have smoother bass response, the chamber induces often more ripple in the upper bass region.
- When the driver is strong enough in the lower mids, then the addidional output of the chamberless horn can make the sound boomy. You can influence this area with horn damping, but only to a certain extent, otherwise the deep bass is suffering. Also the horn-foldings help to reduce the output in this area. But with some drivers it just doesn't fit.
- On the other side sometimes you don't have much choice. Some drivers only work in chambered horns, for example Visaton BG20, some work in chambered as well as in chamberless horns, like Fostex FE126E and FE206E and some work only in chamberless horns, like the Beyma 8AG/N.
It was very interesting for me to find out that many of the vintage horns (like Schmacks) are chamberless horns. I suppose that was to enable the horns to be driven with different driver models, maybe.
Nice greetings, Berndt
Hi Berndt -very interesting; yes, that's been my findings with chamberless horns -in my case the BIB conical corner-horns & modelling in MathCad. They appear very forgiving of drivers used providing cabinet volume is sufficent. I can't say I'm surprised the B200 wouldn't work though -Vas & Qt are way too high for this sort of load. I might see if I can do a BVR (large chamber, short horn) cabinet for it at some point.
Many thanks for sharing your design & experiences with us; I know they've rightly gone down a storm.
Best regards
Scott
Many thanks for sharing your design & experiences with us; I know they've rightly gone down a storm.
Best regards
Scott
Hi,
at lautsprechershop.de, the Viech is sold with a notch filter.
Here's a convolution impulse of Lautsprechershop's notch, made with the linear phase EQ from Waves. It should behave identically to the electronic notch, except it doesn't eat amp power and theoretically sounds better. Yours to try, if you like:
Viech Notch impulse
To use this impulse, you can use the Foobar 2000 media player, and the accompanying Convolution plugin. Both can be downloaded at
http://www.foobar2000.org/
Here's the convolution filter:
http://www.foobar2000.org/components/foo_convolve.zip
More info on convolution:
http://www.hydrogenaudio.org/forums/index.php?showtopic=10611
There is some more discussion of this method in the Cyburgs Needle thread here at diyaudio.com. I haven't got my Vieches built yet, but I like this linear-phase digital notch in my Needles.
at lautsprechershop.de, the Viech is sold with a notch filter.
Here's a convolution impulse of Lautsprechershop's notch, made with the linear phase EQ from Waves. It should behave identically to the electronic notch, except it doesn't eat amp power and theoretically sounds better. Yours to try, if you like:
Viech Notch impulse
To use this impulse, you can use the Foobar 2000 media player, and the accompanying Convolution plugin. Both can be downloaded at
http://www.foobar2000.org/
Here's the convolution filter:
http://www.foobar2000.org/components/foo_convolve.zip
More info on convolution:
http://www.hydrogenaudio.org/forums/index.php?showtopic=10611
There is some more discussion of this method in the Cyburgs Needle thread here at diyaudio.com. I haven't got my Vieches built yet, but I like this linear-phase digital notch in my Needles.
Hi Berndt - - I'm having some difficulty with interpreting proper AJ-Horn input for chamberless horn.
Veich looks good in simulation with Armin's input for a surplus Sammi 8 inch driver with fs ~68Hz.
http://img90.imageshack.us/img90/4690/veich3driverszi8.jpg
Would your input window for Veich look different than Armin Jost's interpretation? How are "BIB" best described for AJ-Horn?
Also, have you worked with Karlson couplers? - I believe Karlson can have merit in certain size and aspect (including open end waveguide HF tube) giving high outputs for low cone deflection but need means of predetermining baffle and other angles for best looking graphs and acceptable outcome. I need some help on K-couplers to figure out best front pipe aspects, etc.
Best wishes,
Freddy
Veich looks good in simulation with Armin's input for a surplus Sammi 8 inch driver with fs ~68Hz.
http://img90.imageshack.us/img90/4690/veich3driverszi8.jpg
Would your input window for Veich look different than Armin Jost's interpretation? How are "BIB" best described for AJ-Horn?
Also, have you worked with Karlson couplers? - I believe Karlson can have merit in certain size and aspect (including open end waveguide HF tube) giving high outputs for low cone deflection but need means of predetermining baffle and other angles for best looking graphs and acceptable outcome. I need some help on K-couplers to figure out best front pipe aspects, etc.
Best wishes,
Freddy
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