Looking for BG RD75 substitute

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Jump to Latest
E

Eldam

Banned
Joined 2012
Could it be not better to design from an avaliable B&G RD 50 ? with a higher XO that the RD75 ! There are fast pro driver around 12" (12P80nd/v2 for instance) to try to match the transcient of a planar with a classic cone driver (with low cone mvt and high electrical damping) ?
 
J

jcx

Member
Joined 2003
floor to ceiling line source is different, shorter won't be a line source to as low a frequency, won't illuminate same height at higher frequency

stacking the 1 m will have a gap in the middle

surprising that there wasn't already a RD-75 knockoff available - probably not the yearly volume to justify 2 sources before but now there are loudspeaker manufacturers needing any source for them
 
E

Eldam

Banned
Joined 2012
Why a Neo 3 should be better than todays AMT or ribbons ?

Yes Neo6... but it low end spl : never saw a measurement in a box with a flat enough curve ! This driver seems not easy to play with despite the dreamed 600 hZ to beginn with ! (Would like such a planar with aflat curve from 600/800 hZ to... ) Unluckily AMTS are too thin sound or distorse in those range... I lurk sometimes on the diy ribbons on this planar section :)
 
E

ezrider4040

Member
Joined 2012
OP here, ty for all the feedback to date. Turns out I am not the first person to ponder using AMT's in a line array. Meet the Steinway Lyngdorf LS https://steinwaylyngdorf.com/products/model-ls-concert
Turns out that this configuration has been well received! Not sure about doing an open baffle though. Will save that discussion for another thread as I would like to keep this one on topic.

Cheers
Derek
 
T

technophile50

Member
Joined 2011
I would buy 50 Fountek FE85 3" Full Range Speaker Driver, 25 per side in a line array, ~$11US ea from parts express. Sell the Fountek ribbons on ebay.
IMHO, the gains from not having a tweeter crossover will outweigh the difference in freq response between the FR & ribbon above 10kHz.
Having made measurements of the HF wavefront curvature on various drivers while investigating line arrays, I have found that the effective center isn't at the voicecoil, as conventional wisdom would have us believe, but 6-9 inches behind the front of the speaker(although I haven't measured the fountek driver), which means that the comb filter effect for closely spaced drivers is much lower than most people think. If you find that comb filtering in the upper treble is a problem, a simple acoustic lens can delay the wave from the center of each driver so that it is aligned with the driver edge wavefront in the vertical direction. The lens will cause frequency variant lobing horizontally, but that may be of benefit in reducing coherent room reflections. If the location of a wall that your subconscious auditory processing determines isn't the same at all frequencies, your brain will acoustically "visualize" it as being like the edge of a grove of trees(more spacious) instead of a flat surface of drywall(restricted).
An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.



An externally hosted image should be here but it was not working when we last tested it.
Fountek FE85 Specifications
An externally hosted image should be here but it was not working when we last tested it.
Fountek Manufacturer Warranty
An externally hosted image should be here but it was not working when we last tested it.
See Catalog Page
 
Last edited:
T

technophile50

Member
Joined 2011
The Fountek has higher excursion, efficiency, and cone area. This probably wouldn't make much difference in an amplitude matched A-B-X blind comparison; the money saved using the Vifa would pay for a miniDSP and a bigger amp. Have you seen any distortion measurements for the vifa, like here?
http://techtalk.parts-express.com/attachment.php?attachmentid=31635&d=1355711192

One could also use the fountek FE87 - on buyout @ $7.10 - and get 5-8 dB boost above 10kHz (good for my 65 year old ears &;>)

One could go for the Eton Symphony 3" Midrange 3-400 @ $169 a pair (less 10% in 25 pair quantities &;>). Plus you get a 10dB boost above10kHz.
I once heard a customer in a high end audio store say, after auditioning a 1200 dollar (circa 1970) 3-way system, say "these sound really nice; do you have anything comparable that's MORE expensive?" Siegfried Linkwitz, upon asking a salesman how can you justify charging these prices [$68k?] for this speaker that has maybe $5000 in parts? was told "the price is a large part of what our customers are paying for."
 
H

h7f9

Member
Joined 2019
ABJensen said:
No the special thing in BG75, is the number 75. It would today be easy to produce a better one. But their is no real marked for it. Most ribbons are short closed back with a transformer.
Click to expand...

You're right! One of the main points on it is it being huge.

But if this is the case a array of multiple smaller ribbons drivers would easily be able to overperform it. Regardless of price, do you have any ribbon driver suggestion that can do it with ease?

Also, what do you believe to be the state-of-art midrange nowadays?
 
A

ABJensen

Member
Joined 2005
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Top Bottom