| Beyma TPL-150 air motion transformer - Click HERE for Original Thread |
| StigErik |
I have a pair ... but no time yet to try them out. I searched this forum, but it seems like there's not much experience with this driver yet.
AMT's are quite rare anyhow. I have tested a couple from Mundorf, I found their AMT2340 to be very good, although its not happy with crossover below 3 kHz.
I hope the Beyma can be crossed over an octave lower, so it can be matched with the 8" Seas Excel magnesium (which is great only below 1500 Hz or so)
Well... I hooked them up and measured them with my Clio (without any baffle). The response is not as smooth as one might expect, but not too bad I think. It will require a couple og LRC networks for EQ to get the response within 1 dB.
Ok, here are the measurements:
http://home.online.no/~st-e-tan/bil...eq-response.gif
http://home.online.no/~st-e-tan/bil...L-150_decay.gif
If anyone else would like to share experience with this driver, I would appreciate it a lot. |
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| Taco |
Unfortunately, I've only experience with the Mundorf 2340 and the Eton Er-4, like you I learned that the Mundorf needs to be crossed > 3 kHz (also rumors are that Mundorf abandons these tweeters from DIY as they encountered a high failure rate due to incompetence). The Er-4 is better in that regard, but has an irregular FR with high distortion below 2 kHz.
I've considered the Beyma but when the high sensitivity isn't needed the Raal 140-15D is a better option. It measures even better and you can hit XO around 1500 Hz rather easy.
I can remember another design of you where you are using the Philips RSQ8P (which I'm also using in a design) and can say that with ease of integration at low XO points the Philips is the better choice.
With regard to sound quality IMHO the Raal tops the Mundorf, Eton and Philips.
Looking at your response graphs, the xo-filter needs some work to equalize the top end response, but a lot of the irregularities come from the unbaffled measurements.
I got best results with the 8" magnesiums when using a 6th order cauer elliptic cross-over around 1300 Hz (crossed to Er-4). |
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| elac310 |
Hi Stig,
I have made some tries with the TPL 150, crossed at 2,5-3kHz with a 6 dB slope, + a serial resistor to take away some sensitivity. Works quite fine in combination with a couple of Audax HM210Z10 which cover the mids (+ a couple of 15 inchers for the low end). I do not often listen Music very loud so I have little experience to say whether they sound stressed or not at high levels (I've fed this set up with a max. of 10 watts or so per channel and my wife would come in the listening room for me to turn the volume down before I can make a fair assesment...) :bawling:
Cheers. |
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