Beyma tpl150h modifications?

Hi all, I just ordered a pair of these amt's from a Spanish distributer over e bay. Before posting them to me they called and e mailed me to let me know of a special offer they had on.
For something like 70€ they replaced the horn with one painted with metallic paint and more Interestingly they replaced or removed what they described as the nylon mesh in front of the driver. They said these mods transformed it's performance (they would say that of course) but they gave some specific figures about the increase in the high treble output, something in the order of a db or two.
I've heard the tpl150h lacks a little here, luckily so do I, Nada past 14k.
Anyone heard of these mods before?
Thanks
Enzo
 

Adhoc1

Member
2012-04-17 12:59 pm
It would be interesting to hear more about that modification, -what the removal of the bug screen may contribute. Who are "they"/ the Spanish distributor and what were those specific figures from them?

I am the building process myself with Beyma TPL 150H. Will be paired with AE TD12 M as LCR-speakers in my listening room. Bass from about 110 Hz and down will be from 4 of AE's PB18 H+ (same as their TD18 H+ but the usual phase plug is replaced with a dust cap.)
 
I'll try and copy the email over.

http://vi.raptor.ebaydesc.com/ws/eB...7940&category=14990&pm=1&ds=0&t=1457808875163

I'm a bit of an anachrophile so the beyma's for me are replacing a beyma cp21f that I used at 10k to fill in where my 60's goodmans axiom 301 extended rangers drop off. I've since lowered the crossover to 6k to reduce beaming and added an audiom 61 (same as the 301 but without whizzer so good to 6k ish) they are both 15ohm so I get 8 ohm ~ 103db/w before bsc. The beyma cp21f is a copy of the jbl 077 I believe and I think they both share a huge responce hump 7-9k which Ive not started to work on. Obviously 2 x 12" running to 6k causes massive combe filtering but the sensitivity has been worth it for me.
The new incarnation will be modular so I can swap mid and bass around, to start with I'll use an axiom 301 open back mid on top of an audiom 61 (or Richard allan cg12 super, 30hz qts 0.1 6% efficient...) in a back loaded horn and play around with whether I cross from one to the other at 300hz and then to the tpl150h at 2000-2500 or whether I run them parallel all the way, perhaps hp filtering the open back at 100-300hz. A very compromised design I know but that's why it's a modular test bed.

I imagine 2 x AE 18" would provide 'adequate' bass as rolls Royce used to say :)
 
Extract from the E mail.
BEYMA´S TPL-150/H & TPL-200/H BY HIGH-REVOLUTION !


THE CUSTOMIZED VERSION WITH SIX METALLIC COLORS HORN COLLECTION :


- THE SURFACES OF THE HORN PERFECLY SMOOTH HELP A BETTER SPREAD OF SOUND, COMPARED

TO THE ORIGINAL SURFACES FINISHING.


- THE BLACK NYLON NET IN FRONT OF THE DIAPHRAGM ATTENUE THE SOUND OUTPUT MORE THAN 10%,

SPECIALLY ON EXTREME HIGH FREQUENCY, IT ATTENUE THE SOUND OUTPUT OF @ 20%.


WITH MY PERSONAL LISTENING TESTS, I CAN DECLARE THAT THE HIGH AND SUPER HIGH FREQUENCY,

WITHOUT THE NET, THE DRIVER WILL HAVE AN INCREASED OUTPUT ON THE FOLLOWING WAY :

+1,5 dB FROM 5KHz TO 10 KHz, +2 dB FROM 10 KHz TO 15 KHz, MORE THAN 3 dB FROM 15KHz TO 20KHz.


THE SOUND :


GREAT IMPROVEMENT IN DEFINITION AND RESOLUTION, WITH MORE DETAILED, FOCUSED, AIRY SOUND,

FASTER TRANSIENT ATTACKS, WITH AN UMBETEABLE MICRO-MACRO

They sent another email since saying the tpl's are on back order, gives me a chance to get the baffles and horns finished.
 
Well, compression drivers profit from removing the mesh with a better resolution, how much depends on the driver. On an Air Motion Transformer it looks a bit different because the opening restriction is much, MUCH less than the small opening at compression drivers because the opening has a (relatively) huge surface, the possible improvement will therefore be likely much less.

The level gain in these dimensions (+3 dB would equal twice the power! Where should have that energy gone to before the mod?) are simply absolutely impossible.

The flatness of the horn mount and the tight fit of the driver is often a problem at a lot of ribbon-, magnetostat- and AMT-tweeters with an attached horn. To even that out might improve the performance of the horn a lot, the distortion will be reduced. But keep in mind not all drivers have such a problem.

Now to the biggest disadvantage: While almost all compression drivers have very slim slots in the phase correction element (which builds the compression chamber too), the AMTs got very big openings and relatively short horn (wg-) throats. That means, they are without the net much more vulnerable to damage or pickup of all kind of objects. Since they are not cheap by any means, I would advise to avoid this kind of modification in any case.
 

manninen

Member
2014-07-16 7:49 pm
I have tpl without horn and cover on top of the speaker.
Ii would be like 10mins job to take nylon mesh and wool felt off but like ICG said possible damage would be other 10mins job cause my cat loves tpl, she cuddles with it after eating.
Im not the one who takes this measurement difference, sorry guys
 
I got another e mail, apparently beyma sent several hundred units to a us distributor and won't have any till the end of the month.
He does have some of the modified units in stock for immediate dispatch though...
Would Sound very convenient to someone with a suspicious mind.
Anyhow he's offered me a pair of minded ones at cost as a good will gesture, which being impatient now I've accepted.
Very likely it's all kosher and the vendor is acting with the best intentions, I don't want to disparage the guy for beyma's delays, just the 'sell' gets my bs detector active.
I'll review them when they turn up.
Enzo
 
I've mounted one of the tpls on my open baffle with axiom 301 under it. Very preliminary crossover work is promising. The sound is good.
Comparing the measurements I'm getting with what I've seen on the net shows the same >10k behaviour ie a drop in spl. The recommendations seem to be to high pass at 2k due to a blip at 1.6-1.8k, the one unit I've measured is very flat from ~ 2.5 to 10k, but does show a -7db blip at 2.3k, I'll see if the other ones displays the same behaviour, if so then they definitely need a highpass ~>2500hz.
The goodmans have no problems getting from tens of hz to 10k pretty flat so 2500 is fine except for the beaming from the 12" cone, nice to have one driver covering the vocal fundamentals though.
I just ordered some some fatal pro m5n12-80 to try in a horn ~250-300 to 2500 which would be another option.
I'll post the measurements tomorrow
 
I've mounted one of the tpls on my open baffle with axiom 301 under it. Very preliminary crossover work is promising. The sound is good.
Comparing the measurements I'm getting with what I've seen on the net shows the same >10k behaviour ie a drop in spl. The recommendations seem to be to high pass at 2k due to a blip at 1.6-1.8k, the one unit I've measured is very flat from ~ 2.5 to 10k, but does show a -7db blip at 2.3k, I'll see if the other ones displays the same behaviour, if so then they definitely need a highpass ~>2500hz.
The goodmans have no problems getting from tens of hz to 10k pretty flat so 2500 is fine except for the beaming from the 12" cone, nice to have one driver covering the vocal fundamentals though.
I just ordered some some fatal pro m5n12-80 to try in a horn ~250-300 to 2500 which would be another option.
I'll post the measurements tomorrow

Hi. Hopefully you came across my thread where I was asking about horn loaded midranges to pair with a TPL-150H, and the M5N12-80 came out as a top candidate. What kind of horn are you thinking of to go with the Faital Pro?
 
Thanks for your reply, I've been reading lots of threads about midrange drivers to match the tpl150h, and the horn loaded cone thread etc.
I can well see how it's easy to become really involved with horns, I'm just past the point where my wife starts complaining already so a straight bass horn may be a while off!
I saw the m5n12-80 was recommended, but being new to horns I'm a little confused as to the best way to go, it's going to have to be diy as 250hz horns are more than I'm prepared to spend on an experiment. I made a pi conical horn that I've been playing with, I was planning to have a go at a pair of 220hz tactrix horns that an online calculator coughed up.
Do you have any recommendations?
Do you think a horn loaded m5n12-80 can make it to 2500hz?
Enzo
 
Thanks for your reply, I've been reading lots of threads about midrange drivers to match the tpl150h, and the horn loaded cone thread etc.
I can well see how it's easy to become really involved with horns, I'm just past the point where my wife starts complaining already so a straight bass horn may be a while off!
I saw the m5n12-80 was recommended, but being new to horns I'm a little confused as to the best way to go, it's going to have to be diy as 250hz horns are more than I'm prepared to spend on an experiment. I made a pi conical horn that I've been playing with, I was planning to have a go at a pair of 220hz tactrix horns that an online calculator coughed up.
Do you have any recommendations?
Do you think a horn loaded m5n12-80 can make it to 2500hz?
Enzo

We are very much on the same boat. Not sure that is good news for you, though :eek:

I'm new to horns as well. Been doing a lot of reading. My baseline is the Edgar Tractrix 300Hz horn found in the download section at volvotreter.de.
  • It is 2:1 width:height aspect ratio which I think should help with a tall horn like the TPL in terms of center-to-center spacing (and hence lobbing).
  • It si DIY, which is half the fun.
  • It's a proven design that I can adapt with online help and available simulators such as Hornresp.
As of now I'm thinking it can work to 2500Hz, but there will be a dispersion of 40 to 50° from 1500 to 2500Hz which is not what I was hoping for considering the TPL-150H at 80° (horizontal). But TBD if I can hear that...

Below is a simulation with Hornresp. Please note I'm learning how to use it, so I could be easily making some sort of mistake here. It gets to 100dB @ 1W at 400 and 2500Hz. I'm hoping to get closer to 104dB while keeping it flat. On my thread it was mentioned Hornresp might be underestimating sensitivity at the higher end.

BTW, like you, I'm not going for bass horn - at least for now :D
 

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Great to be in contact with someone who is after the same thing.
I read some papers by Edgar, so think I know the horn your simulating. I've just drawn out a template for a 215hz tactrix, 60cm wide by 35 high and 38 long. the pi conical horn I made, with the only sensitive 8" I had to hand, a pioneer pax 8l loaded from 260 -1300hz and it's mouth is 60 x 30.
I just built a pair of folded back loaded bass horns, they measure pretty flat to 38-40hz and move a fair bit of air with a watt. The output from the mouth goes up to 250-300 hz so I'd love to be able to go from 250 to the tpl150h. I'll try and upload some captures.
Looking at the m5n12-80 direct radiating it seems to nose dive after 1500hz and then keep going to 5k. So flat to 2500 may be optimistic, my goodmans do 98db so I'd be looking to match the tpl150h too.
Enzo
 

Thanks for posting these.

I see you are using a 4.7uF cap in front of the TPL. Is that purely for protection? Where is the 1mH coming from?

Could you change the vertical axis in both graphs, increasing scale, so we can have a better understanding of what's going on? Something like 5dB per centimeter of screen, for example.

What driver is inside the horn?