Hello everyone! This is my first post and hopefully the beginning of a successful foray into the world of high-efficiency full-range DIY speakers!
I've developed an interest in full-range speakers as I like the idea of pursuing the faithful reproduction of the immediacy and impact but also the delicacy and nuance of a musical performance, especially classical music and jazz. What better method to achieve these goals than the use of lightweight, low-inductance, high-efficiency full-range drivers, correct?
I'd like to ask the many experts on this forum what are the typical sound pressure levels achieved with the various full-range drivers. I'm especially interested in maximum SPL when mounted in an open baffle configuration as this is perhaps the easiest design for a first-time DIYer like myself.
Since I'll be using the speakers to reproduce classical music in a 6,000 cu. ft. space, maximum SPL as a design criteria is important to me. Looking at the data on these drivers, most seem to have limited excursion capabilities which may indicate limited dynamic output capability in an open baffle. Are there any full-range drivers that have high excursion and high power handling capabilities for increased output capability in an open baffle?
I'd also like to ask about recommended amplification for full-range drivers. Their high efficiency and highly revealing nature seems well suited for tube amplifiers. Are tube amps strictly recommended? Do solid state electronics reveal too much grain?
I appreciate any help you may provide! 🙂
I've developed an interest in full-range speakers as I like the idea of pursuing the faithful reproduction of the immediacy and impact but also the delicacy and nuance of a musical performance, especially classical music and jazz. What better method to achieve these goals than the use of lightweight, low-inductance, high-efficiency full-range drivers, correct?
I'd like to ask the many experts on this forum what are the typical sound pressure levels achieved with the various full-range drivers. I'm especially interested in maximum SPL when mounted in an open baffle configuration as this is perhaps the easiest design for a first-time DIYer like myself.
Since I'll be using the speakers to reproduce classical music in a 6,000 cu. ft. space, maximum SPL as a design criteria is important to me. Looking at the data on these drivers, most seem to have limited excursion capabilities which may indicate limited dynamic output capability in an open baffle. Are there any full-range drivers that have high excursion and high power handling capabilities for increased output capability in an open baffle?
I'd also like to ask about recommended amplification for full-range drivers. Their high efficiency and highly revealing nature seems well suited for tube amplifiers. Are tube amps strictly recommended? Do solid state electronics reveal too much grain?
I appreciate any help you may provide! 🙂
I recommend the single driver open baffle idea for folks listening in the near field in moderate rooms. 6,000 cubic feet is awfully large. I have a smaller space, and I tend to listen at 85ish db. I find a single driver OB to be plenty, but some folks listen much louder.
More excursion isn't the answer, as you get more doppler distortion. You never want to be able to see a fullrange speaker cone moving! If you are concerned about dynamic range, you'll probably be most happy with some help in the bass. A proper enclosure (the bigger the better) would certainly help increase the dynamic range. But, you should also consider a helper woofer setup. I'm working on such a system now. Of course, to gain dynamic range, you need to put a high pass filter on the fullranger. Biamping is preferred, but passive filters work too. I will probably use a combination of the two.
You can also consider starting with a single driver OB. Wood is cheap and OB construction is easy. If you decide that you need more, then you can buy some woofers!
You may use any amps you wish, but good ones are preferable! Good amps come in both tube and SS. I prefer the former, but I could live happily with my chip amp. I recently had a little Sure TA2024 class D amp in my system and it sounded pretty good given the price. I haven't had any big SS amps in the system, but a couple of receivers have passed through the house. None sounded too grainy, but they were muddy and unrevealing. Which ever type you choose, remember that quality is more important than power.
Paul
Wild Burro Audio Labs - DIY Full Range Speakers
More excursion isn't the answer, as you get more doppler distortion. You never want to be able to see a fullrange speaker cone moving! If you are concerned about dynamic range, you'll probably be most happy with some help in the bass. A proper enclosure (the bigger the better) would certainly help increase the dynamic range. But, you should also consider a helper woofer setup. I'm working on such a system now. Of course, to gain dynamic range, you need to put a high pass filter on the fullranger. Biamping is preferred, but passive filters work too. I will probably use a combination of the two.
You can also consider starting with a single driver OB. Wood is cheap and OB construction is easy. If you decide that you need more, then you can buy some woofers!
You may use any amps you wish, but good ones are preferable! Good amps come in both tube and SS. I prefer the former, but I could live happily with my chip amp. I recently had a little Sure TA2024 class D amp in my system and it sounded pretty good given the price. I haven't had any big SS amps in the system, but a couple of receivers have passed through the house. None sounded too grainy, but they were muddy and unrevealing. Which ever type you choose, remember that quality is more important than power.
Paul
Wild Burro Audio Labs - DIY Full Range Speakers
I would like to violently agree with Paul.
Multiple drivers loudspeakers were designed to overcome the limits of intermodulation of single drivers playing orchestral music at realistic volumes.
I love OB speakers, and my ultra frugal 3 way Tri-amped OB got rave reviews in a hotel meeting room that was 6000 Sq feet or larger.
If I were to do it, I would use a wide range 8" or larger "midrange" with 2 by 15" Alpha or Beta (or another 15" high QTS woofer)
Parts-Express.com: Eminence Alpha-15A 15" Driver | alpha-15a 15" guitar speaker 15" keyboard speaker pa driver 200 watt driver
Parts-Express.com: Eminence Beta-15A 15" Driver | beta-15a pa woofer bass guitar speaker pa driver 15" pa woofer
Several sites have OB calculators to determine maximum SPL for drivers depending on baffle size. Part of the calculation for my crossover is to check if I am exceeding Xmax at my crossover frequency with my "midrange".
Another thought, some of the new horn speakers might be more suitable for your situation. No personal experience, however.
Multiple drivers loudspeakers were designed to overcome the limits of intermodulation of single drivers playing orchestral music at realistic volumes.
I love OB speakers, and my ultra frugal 3 way Tri-amped OB got rave reviews in a hotel meeting room that was 6000 Sq feet or larger.
If I were to do it, I would use a wide range 8" or larger "midrange" with 2 by 15" Alpha or Beta (or another 15" high QTS woofer)
Parts-Express.com: Eminence Alpha-15A 15" Driver | alpha-15a 15" guitar speaker 15" keyboard speaker pa driver 200 watt driver
Parts-Express.com: Eminence Beta-15A 15" Driver | beta-15a pa woofer bass guitar speaker pa driver 15" pa woofer
Several sites have OB calculators to determine maximum SPL for drivers depending on baffle size. Part of the calculation for my crossover is to check if I am exceeding Xmax at my crossover frequency with my "midrange".
Another thought, some of the new horn speakers might be more suitable for your situation. No personal experience, however.
I'll 3rd that. If you want an OB with a FR driver, and you want it to play effortlessly at high volumes (or with lots of dynamics) in a biggish room (a bit smaller than mine), then you really need a FAST (ie helper woofers). Definitely best bi-amped (almost necessary for the more efficient FRs).
Or tackle something like Sachiko. 10-20 w (especially if an amp that clips gracefully, like Red Light District), you should be good to go.
The 1st trades cabinet simplicity for electronics complexity (& an XO)., the 2nd box complexity, but amp can be simple.
dave
Or tackle something like Sachiko. 10-20 w (especially if an amp that clips gracefully, like Red Light District), you should be good to go.
The 1st trades cabinet simplicity for electronics complexity (& an XO)., the 2nd box complexity, but amp can be simple.
dave
For large scale orchestral music, I certainly agree with those who have already suggested a FRD on OB with a helper woofer. I have built MJK's small passive OB using Fostex FF85k and Eminence Alpha 15a. There are a couple threads about this design. You may also check out Martin's web site-- Quarter Wavelength Loudspeaker Design He has several papers on OB. And if you are seriously wanting to 'roll your own', his MathCAD worksheets are great for modeling designs.
Cheers, Jim
Cheers, Jim
Thanks for all the advice! 🙂
I find the full-range design approach incredibly fascinating. It wasn’t automatically intuitive to me that Doppler phenomena would have to be considered when using a single driver to cover a broad spectrum. I suppose that above a certain frequency, large (i.e. visible) driver excursions cause Doppler shifts which probably sound somewhat like a garble of low amplitude warble tones centered on the given frequencies being reproduced, correct? Thanks for pointing this out Paul! BTW, have you considered developing a variant of the Betsy driver with a phase plug?
Thanks Doug for the tip about OB calculators. I find it rather humorous that when I Googled “OB calculator” I got hits on pregnancy related websites to help determine delivery due dates! 😱 Searching for “open baffle calculator” yielded better results and I found the “EDGE” baffle diffraction simulator program. I found additional resources such as “Jeff Bagby's Loudspeaker Design Software” at audio.claub.net and “Hifi Speaker Design” downloads at mh-audio.nl.
Dave, thanks for recommending a “helper woofer”. I must admit that I’m trying to catch up with all the acronyms used on this forum (is there a glossary page?), so thanks for letting me know the meaning of “FAST”. Thanks Jim for telling me about Martin King’s website. Lots of great material and I’m sure the modest fee for using his worksheets is well worth it.
I’m off now to learn how to use the various design utilities I found. Please let me know which other design tools you recommend. Thanks again for all the help… it’s really great to be a member of this forum!
Mike
I find the full-range design approach incredibly fascinating. It wasn’t automatically intuitive to me that Doppler phenomena would have to be considered when using a single driver to cover a broad spectrum. I suppose that above a certain frequency, large (i.e. visible) driver excursions cause Doppler shifts which probably sound somewhat like a garble of low amplitude warble tones centered on the given frequencies being reproduced, correct? Thanks for pointing this out Paul! BTW, have you considered developing a variant of the Betsy driver with a phase plug?
Thanks Doug for the tip about OB calculators. I find it rather humorous that when I Googled “OB calculator” I got hits on pregnancy related websites to help determine delivery due dates! 😱 Searching for “open baffle calculator” yielded better results and I found the “EDGE” baffle diffraction simulator program. I found additional resources such as “Jeff Bagby's Loudspeaker Design Software” at audio.claub.net and “Hifi Speaker Design” downloads at mh-audio.nl.
Dave, thanks for recommending a “helper woofer”. I must admit that I’m trying to catch up with all the acronyms used on this forum (is there a glossary page?), so thanks for letting me know the meaning of “FAST”. Thanks Jim for telling me about Martin King’s website. Lots of great material and I’m sure the modest fee for using his worksheets is well worth it.
I’m off now to learn how to use the various design utilities I found. Please let me know which other design tools you recommend. Thanks again for all the help… it’s really great to be a member of this forum!
Mike
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Phase plugs exist for Betsy...
I haven't decided exactly how to deal with them, they were actually a mistake when getting FE16x plugs made (the wood turner made skinny, short B200 plugs). You can get unfinished blanks from me as long as i have these. $20/pr.
Another idea was to ship them all to Paul on consignment but i haven't talked to him about that -- still trying to figure out how to remedy the conductive cone problems with my 1st gen Betsy's.
I'll take a close-up pic later (thot i had sent one to Paul, but can't find it if i did)
dave
Does this mean there's actually a DIY market for phase plugs? 😕 Thanks for the offer Dave but this is too sophisticated a project for me as I believe there would be many variables to consider that govern the interaction between the whizzer cone and phase plug in order to get things just right.
Mike
Demand for phase plugs was what got planet10-hifi started... little ones for the Radio Shack 40-1197.
They are pretty easy to install. Cut off the dust cap (at least on the ones i have (and the HA FR8C also built by Misco), take care not to remove the whizzer as well (paul, you may consider having them bond the whizzer seperately to the outside of the coice coil like on the Fostex). With blanks, finish them to taste, put a couple flat headed screws into the bottom, place & centre.
planet_10 hifi
dave
Member
Joined 2002
I'll add to some photo's 🙂
yes cal, we know that's your favorite cassette.
An externally hosted image should be here but it was not working when we last tested it.
yes cal, we know that's your favorite cassette.
An externally hosted image should be here but it was not working when we last tested it.
are those woofers open baffled too? Dave, is there a big difference with the same baffle width when the OBs are outside or inside (i think i saw them in a pic of your labs too), i mean in the outside their radiation should be closer to infinite baffle, is it a big udible difference?
So full-range drivers don’t have to be designed from the ground up with a phase plug as an initial design criteria? Based on all the different phase plug and whizzer cone designs I’ve seen, which appear to be the result of careful optimizations, I thought it would be a little more involved.
Not OB and not unfiltered, but this fullrange speaker can do bass and high SPL: Visaton - Lautsprecher und Zubehör, Loudspeakers and Accessories
The woofers were yes. The baffle was a packing crate (check out the 6th annual VI diyFEST thread for more -- there is a gallery Ruth put up). Not optimal at all, but fun.
In the lab placement is not optimal. They don't really fit upstairs but they sound really good. They sound even better outside.
dave
No. From the feedback (& personal experience) quite a few of them should have (but it does increase cost)
dave
I happened to be looking at the Audience A3 and I was reminded of your post. They claim to have designed a full range driver with a long stroke. I don't see how this could be a good thing. Certainly they haven't found a work around for the doppler or intermodulation distortion, have they?
I took a look at the A3 specs and the review on their website and I have the following questions:
- According to the review this driver begins to roll off at 200 Hz in a sealed enclosure. Would the cone excursions at this frequency at high SPL be large enough to cause Doppler and IM distortion given the small effective piston area?
- At what excursion limits and at what frequency threshold do Doppler effects begin to manifest themselves?
- Would it be feasible to create an OB speaker with a sealed sub-enclosure housing two A3 units in a dipolar configuration with a "helper woofer" in true OB configuration handling 200 Hz and below?
Hemp Acoustics FR8c, 8" FR with whizzer
HA has been out of business for a while now
dave
Nope, they haven't (moreover, can't, it's realities of a moving surface). It's why the limits of Fostex, lowther, etc, aren't so bad, in real-world apps- you don't want your fullrange moving more than a little tiny bit anyway, so you can reap the sensitivity benefits of gap/coil heights that are very close.
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