Hey Scott!
What makes you like B&C 6PEV13 better than Audax PR170MO? That would help me learn.
I take you would choose a rectangular Edgar Tractrix. How high would you cross it over to a TPL-150H?
cheers!
High BL is good and low Le allows reach into higher frequencies with less fall off. Expect a +10dB gain from design frequency to about 4kHz to 5kHz. Then about 12dB loss towards 20kHz.
Another mid that an work is B&C 6MDN44. Direct radiator is 96dB. In a horn it can be really high.
Yes, that 5MR450 in a horn is one of the cleanest sounds I have heard.
Yep, understanding what you say about time and audio, btw half of my pleasure with this hobby is to understand all the brainstorming of ideas and progress with the process of the stuffs people are making in our hobby ! For me it's better to read than any Agatha Cristy... btw I read a lot, not only audio, so... have few time myself for the diy phase (I solder more on the digital side of it) as my hand skill with bigger Tools is not too good !
The thing I tried to explain you with the Synergy is : you will need only one medium driver if you place it at the Apex. The Beyma will be a little further in front of it on two rods through the top and bottom walls : its point source, but yes tricky to realize and time consuming... but I'm sure you will be surprised to ear the mid of a 3"/4" with few mvt in a horn at its apex: many found it better than any compression driver in sound result and more linear ! My idea of the rods to tilt on/off the AMT Beyma in the middle of the horn or near the mouth of a horn has never been seen before... I think it's a good idea ! Only your two 10" Beyma could be on the two other walls of the horns with a fireing port : good snap ! The scan speak being linear to 10 K : it will have no problem if Xoed around 2.5 k to have a stuff like the Beyma in front of it...as far your measure and have a FIR like you do
. The little 3"/4" being at the apex can deliver the same efficienty than the Beyma and a subjective good transcient (an tons of less distorsion) as the cone is doing far more less movements : that's the advantage of the horns : air impedance adaptator !But yes Odd, I assume... I try, I try as I know you have already the Beyma AMT and I wanted myself to buy two... you remember
!Scott advices are always good and very experienced (not mines)
... and X has some experience now with horn... (3 per month... foam designs )looking forward to see your progress,
best regards
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The B&C has a phase plug (bullet)
The PR 170zo has a phase plug bullet
The PR 170mo does not, and exhibits ragged response near the top of it's range. The best sounding cone driver type mid range units I have heard all
possessed phase plugs, either flat faced, or bullets.
I would cross to the TPL at somewhere between 5 & 6 kHz.
Hi Eldam,
Audax says 500-8K, but personally I would not be comfortable above 2k, and I really don't like 2 K crossover points. I prefer sealed for mid range, but at least one enthusiast has used the MO version in PAIRS per side, open baffle, claiming excellent results.
QUOTE from the spec page:
The PR170MO was specifically designed for high quality professional sound reinforcement systems. Its efficiency and power handling capacity are exceptional for a direct radiation transducer in its category. The flat foam suspension is coated with a cisco-elastic compund in order to minimize the standing waves and cone break up. It is ideally suited to cover the frequency range from 500Hz to 8kHz. This driver is recognized worldwide as the reference in prestigious professional applications.
You can try the PR170M0 in around 0.2 cubic foot sealed (F3 of 190Hz).
Attachments
, thanks. Should do work well with a flatered impedance in the passive network or DSP !Size Matters
If you are on a budget, buy dead CD carcasses and replace the diaphragm/voice-coil assemblies.
Buy them on EBay or here:
Jammin Jersey: Speakers Horns Drivers Crossovers Tweeters
For a more recent, albeit more expensive, candidate
BMS 4599NDHE
http://www.bmsspeakers.com/fileadmi...ssion_drivers/neodymium/bms_4599nd_curves.jpg
BMS 4599NdHe Neodymium Dual Voice Coil Mid frequency Compression Driver with aluminum demodulation rings- BMS 4599NdHe - BMS 4599NdHe lightweight neodymium 2 inch dual voice coil mid frequency compression driver with aluminum demodulation rings. BMS
Comparison of the Horn and PWT performance curves will demonstrate the affect of horn artifacts.
The size of the horn you use will be the primary determinant of the lower frequency bound of usable mid-range unit response. When the wavelength of the lowest frequency to be passed is larger than horn dimensions, the horn function is lost both in regards control of the radiation pattern and driver loading. Ideally the mid-range pattern and that of the bass driver(s) should match in the frequency overlap region, so your horn design should work at least 1/2 octave below the c/o point using a steep sloped high pass filter.
Designing a phase plug needed to horn load a open frame mid-range driver
is like accepting an invitation to a nightmare. While shaping the outgoing wave front, standing wave and diaphragm breakup modes must also be addressed in the design as well. Study of the work of Smith, and Dodd will give you some insight on how to do it right. Use of cone drivers with inverted dust caps make this effort a lot easier. Beware there are some obstructions placed in the center of driver diaphragms that are called "phase plugs" but are not. The characterization in these instances is a misnomer.
Regards,
WHG
Thanks for the links!
I had actually seen the first one (JBL PT guides), and also the one on CMCD drivers. The 2485 looks interesting, although my search suggests it's a vintage product apparently not being sold anymore. So as challenging, if not more, as finding a CMCD-61. Plus the 2485 spec shows it coupled to a 2366 horn, which is huge
Is there a place where I can buy 2485 that you know of? And how well would they work well with a different type horn, hopefully smaller? Don't need 118dB...105 would suffice
If you are on a budget, buy dead CD carcasses and replace the diaphragm/voice-coil assemblies.
Buy them on EBay or here:
Jammin Jersey: Speakers Horns Drivers Crossovers Tweeters
For a more recent, albeit more expensive, candidate
BMS 4599NDHE
http://www.bmsspeakers.com/fileadmi...ssion_drivers/neodymium/bms_4599nd_curves.jpg
BMS 4599NdHe Neodymium Dual Voice Coil Mid frequency Compression Driver with aluminum demodulation rings- BMS 4599NdHe - BMS 4599NdHe lightweight neodymium 2 inch dual voice coil mid frequency compression driver with aluminum demodulation rings. BMS
Comparison of the Horn and PWT performance curves will demonstrate the affect of horn artifacts.
The size of the horn you use will be the primary determinant of the lower frequency bound of usable mid-range unit response. When the wavelength of the lowest frequency to be passed is larger than horn dimensions, the horn function is lost both in regards control of the radiation pattern and driver loading. Ideally the mid-range pattern and that of the bass driver(s) should match in the frequency overlap region, so your horn design should work at least 1/2 octave below the c/o point using a steep sloped high pass filter.
Designing a phase plug needed to horn load a open frame mid-range driver
is like accepting an invitation to a nightmare. While shaping the outgoing wave front, standing wave and diaphragm breakup modes must also be addressed in the design as well. Study of the work of Smith, and Dodd will give you some insight on how to do it right. Use of cone drivers with inverted dust caps make this effort a lot easier. Beware there are some obstructions placed in the center of driver diaphragms that are called "phase plugs" but are not. The characterization in these instances is a misnomer.
Regards,
WHG
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When you sketech out your desired controlled-directivity polar plot vs. frequency, you can also sketch out the horn size for construction.
The lower frequency of transmission for a horn mouth exit area:
--Mouth Area Exceeds: (cut-off wavelength ^2) / 4*Pi
500Hz recommended horn area > 60sqin
300Hz recommended horn area > 160sqin
200Hz recommended horn area > 360sqin. 20" * 20" conical horns are common DIY construction
P.S. The JBL CMCD-81 has been updated to CMCD-82H claiming improvements in response. Measurements are hard to find.
The lower frequency of transmission for a horn mouth exit area:
--Mouth Area Exceeds: (cut-off wavelength ^2) / 4*Pi
500Hz recommended horn area > 60sqin
300Hz recommended horn area > 160sqin
200Hz recommended horn area > 360sqin. 20" * 20" conical horns are common DIY construction
P.S. The JBL CMCD-81 has been updated to CMCD-82H claiming improvements in response. Measurements are hard to find.
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200Hz = 67.75" wavelength
67.75" ^ 2 = 4590sqin
4590 / 4*Pi = 365sqin ~19.1" x 19.1"
This note was a reminder on midrange horn mouth area to allow sketches with the 9" x 9" horn on the Beyma TPL-150H. If you want Directivity Control at low frequencies, it requires large horns.
A good 10" midbass cone speaker can reach 100Hz F3.
One of the reasons SEOS Econowave designs are so popular for HT.
67.75" ^ 2 = 4590sqin
4590 / 4*Pi = 365sqin ~19.1" x 19.1"
This note was a reminder on midrange horn mouth area to allow sketches with the 9" x 9" horn on the Beyma TPL-150H. If you want Directivity Control at low frequencies, it requires large horns.
A good 10" midbass cone speaker can reach 100Hz F3.
One of the reasons SEOS Econowave designs are so popular for HT.
Thanks again. I had seen that BMS driver and indeed looks great, but I think it would be a mismatch with my TPL tweeter. The BMS is $1150 each and gets to 9kHz and the TPL tweeter is $500, which is expensive for a tweeter, and has the benefit of playing easily from 2kHz - some are using it starting at 1.1kHz (e.g.; Vapor Audio). So this BMS seems like a waste if partnered with a TPL. Plus the BMS starts at 200Hz and I've seen several people reporting compression drivers sound rather thin in the 200-500Hz range...which is an important range to get right in my case.
I agree creating a phase plug is not for me at this stage of my learning. If it gets THAT complicated I might as well go with a direct radiator and call it a day. And maybe later explore cones. But from the other posts it would seem there are alternatives out there. What's your point of view regarding the phase plug included in the B&C 6PEV13 or Audax 170zo, for example? Xrk also shows an interesting measurement of that PRV driver in an Edgar Tractrix horn, right?
Thank you!
Unfortunately not only measurements are hard to find, but also these drivers seem hard to buy. And hardly found on fora threads, so makes me wonder. Been in touch with Pooh, though, and he really likes it.
Thanks for the horn size guidelines. From what I've seen in threads, people using Tractrix horns seem to operate them starting about 150Hz above the horn's rating. So a 200Hz Tractrix seems to be run from 350Hz upwards, and so on. Reasonable rule of thumb at this stage?
In the USA, you can purchase the CMCD-82H driver on eBay for $320
Driver, Mid Freq. 2169H (339111-001X)
JBL 2169H 8" Woofer for STX 835 | eBay
============================
I have also seen the phase plug on eBay. Sometimes the speaker seller also offers the phase plug.
Phasing Plug 338471-001
Gasket, Phasing Plug 339403-001
====
JBL Phasing Plug for SRX735 / STX-835
JBL Phasing Plug for SRX735 STX 835 | eBay
=============
JBL's most common horn/waveguide 6.5" speaker (JBL 165H) is easy to find on eBay or just Google for a vendor.
Alternative vendor (B&C..Beyma..Faital) may sell better 6"-6.5" drivers for a midrange horn than this JBL. There are DIY sites illustrating how to build phase plugs.
Horse & Cart
The BMS with its dual voice-coil/diaphragm configuration will deliver a predigest amount of output in your frequency range of interest so long as the horn you use adequately loads the driver at the bottom end. The only issue you have here is horn size, and here bigger is better. The design chosen for the speech range, where the ear is most sensitive, should determine the driver selection and baffle design made to cover the audio frequency extremes, both high and low. Note that if the c/o filter slopes are to be kept low, the overlap region where the two drivers are expected to work together will span a frequency band in excess of four octaves. When voicing the drivers to work together, the more latitude you have, the better. Unfortunately, value engineering comes after prototype development. The big picture: unless you are pursuing an all-horn system design, I would give up the chase on a large format mid-range horn because that is the only reason for its use outside a P.A. venue.
On your other questions, I will get back to later today.
Regards,
WHG
The BMS with its dual voice-coil/diaphragm configuration will deliver a predigest amount of output in your frequency range of interest so long as the horn you use adequately loads the driver at the bottom end. The only issue you have here is horn size, and here bigger is better. The design chosen for the speech range, where the ear is most sensitive, should determine the driver selection and baffle design made to cover the audio frequency extremes, both high and low. Note that if the c/o filter slopes are to be kept low, the overlap region where the two drivers are expected to work together will span a frequency band in excess of four octaves. When voicing the drivers to work together, the more latitude you have, the better. Unfortunately, value engineering comes after prototype development. The big picture: unless you are pursuing an all-horn system design, I would give up the chase on a large format mid-range horn because that is the only reason for its use outside a P.A. venue.
On your other questions, I will get back to later today.
Regards,
WHG
dome medium in a horn
This one from 700 to the tplH-150 ? in the right horn to get 100 dB ? (so a 80x30° horn !)
http://www.toutlehautparleur.com/media/catalog/product/datasheet/morel/EM_1308-8.pdf
?
This one from 700 to the tplH-150 ? in the right horn to get 100 dB ? (so a 80x30° horn !)
http://www.toutlehautparleur.com/media/catalog/product/datasheet/morel/EM_1308-8.pdf
?
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We would like to get much lower than 700Hz
(otherwise a compression driver might as well be used)
He wants to obtain response possibly as low as 400Hz.
For me, I would like to get as low as 250, but would settle on 350.
Not sure I'm interpreting you here. I am not after an all-horn design: 350/400 to 80Hz will be played by direct radiators, and also the subwoofers below 80Hz. So you are suggesting I go with a direct radiator midrange driver, right?
And since you mentioned size matters, would you suggest a 10" midrange and compromise some on beaming and lobbing, would you go 6.5" to minimize the above maybe at the expense of size, or compromise on an 8" midrange?
FWIW, my digital crossovers allow very steep slopes plus time-alignment of drivers.
Thanks!