What are the possibilities for a modern day Bose Type "901". Just wondering if you use more modern and well built full range speakers and a MiniDSP unit. Front DSP would be different from rear DSP output - say use a 4 channel DSP... Use built in amplification via CLASS D.
What might the possibilities be? I have some extra 3116 and a TPA 3251 Aiyama and a miniDSP 2x4HD for testing concept
What drivers might be considered?
What might the possibilities be? I have some extra 3116 and a TPA 3251 Aiyama and a miniDSP 2x4HD for testing concept
What drivers might be considered?
Off couse it is possible. FaitalPro makes some nice sounding well behaving 4" fullrangers.
But the real question is why would you listen to only one fullrange directly and nine others facing back wall. Do you like to listen primarily to reflected delayed sound? If you do, its fine with me. But i prefer direct sound.
But the real question is why would you listen to only one fullrange directly and nine others facing back wall. Do you like to listen primarily to reflected delayed sound? If you do, its fine with me. But i prefer direct sound.
At one of the college bars I formally attended, they just turned them around so the 8 speaker side faced front. I could see where it'd be fun making the 8 behave like a phased array antenna, where by using DSP delays you could steer the beam around the room. Maybe the solution for a "wider sound stage" in small rooms? ;')
I've always liked the idea of the 901s. I found the disappointing in practice. But I think that could be remedied with modern equipment.
My blue-sky concept would start with the general shape of the 901, but add a third rear panel that was angled upward, to increase the dispersion range. Then I'd improve the front-facing drivers. Make sure the front facing experience was solid. Then finally, tune the frequencies and levels sent to the different sections of the speaker, either manually, automatically with microphone feedback, based on modeling, etc. The back shouldn't simply play the same thing as the front, and it should be time-aligned as much as possible.
My blue-sky concept would start with the general shape of the 901, but add a third rear panel that was angled upward, to increase the dispersion range. Then I'd improve the front-facing drivers. Make sure the front facing experience was solid. Then finally, tune the frequencies and levels sent to the different sections of the speaker, either manually, automatically with microphone feedback, based on modeling, etc. The back shouldn't simply play the same thing as the front, and it should be time-aligned as much as possible.
Interesting. The <120 Hz region is improved! I wonder what it would look like on one of those spectral graphs, something that could consider "space" and "size", since the 901's were designed to sound "big" like a concert hall.
Not a great speaker overall, clearly. Those full-range drivers are great if you really love mid-bass, I guess. Very much a blunt instrument.
Not a great speaker overall, clearly. Those full-range drivers are great if you really love mid-bass, I guess. Very much a blunt instrument.
Thanks freddi.
If at all possible, I would have loved that frequency response a little bit more averaged.
1/3 octave or something?
You don´t state it on the graph, but it looks like you used a very narrow filter; in that case almost any speaker will give a very jagged curve, specially if near floor/reflections.
In any case, I can mentally integrate it 🙂 a bit to have a better idea.
If at all possible, I would have loved that frequency response a little bit more averaged.
1/3 octave or something?
You don´t state it on the graph, but it looks like you used a very narrow filter; in that case almost any speaker will give a very jagged curve, specially if near floor/reflections.
In any case, I can mentally integrate it 🙂 a bit to have a better idea.
Hi JMFahey
sorry about those 1/24 octave curves. Here's just the front and rear curves. I think the red traces shows comb filtering from its 8 drivers.
(btw - do you manufacture a high power cone tweeter? -if so I'd like to its specs)
sorry about those 1/24 octave curves. Here's just the front and rear curves. I think the red traces shows comb filtering from its 8 drivers.
(btw - do you manufacture a high power cone tweeter? -if so I'd like to its specs)
Attachments
The only thing engineered for sound quality about the 901s was the marketing brochure. And before I get flamed, I’ll take this opportunity to mention that in a 2000 seat auditorium where I was once the sound engineer, I took down the original Bose 802s and replaced them with 901s with the front driver removed and the cabinets reversed for the house PA. With proper EQ and amp racks mounted behind the speakers on the other side of the proscenium wall, they were OK. In fact Julie Andrews producer specified Bose as the preferred system for her. When she performed on our auditorium, after the concert he said that our system was the best he had heard anywhere in the world touring with Julie Andrews. It’s all in the details.
Bose 901s flopped for various reasons, there are threads about it.
The patents have expired, you can make your own, no problem.
Basically there is interference from all the drivers, the sound is not in phase, and is dull.
The patents have expired, you can make your own, no problem.
Basically there is interference from all the drivers, the sound is not in phase, and is dull.
This is the most thorough review from both an objective and subjective standpoint on the Bose 901 anywhere. It behooves the OP to read & study it first prior to embarking on his venture. There are acoustical abominations that were made with this design (if your premise is “accurate” hifi) and like another member said, Bose’ research was really in marketing, and not really anything else.
https://www.erinsaudiocorner.com/loudspeakers/bose_901_series_v/
You won’t get anything more accurate than measuring with a $100K Klippel. Period.
But this is diy…do as you see fit.
Best, Anand.
https://www.erinsaudiocorner.com/loudspeakers/bose_901_series_v/
You won’t get anything more accurate than measuring with a $100K Klippel. Period.
But this is diy…do as you see fit.
Best, Anand.
Sure, you could pay for 18 full range drivers, do the necessary EQ, and it will still sound like a limited full range with no bass, erratic upper mid, totally blurred imaging, and no top end needing a room just so for the reflection game to work.
Bose had a interesting idea. So he built a speaker to solve that one idea. Did not solve all the rest. There is a reason that design went away.
Bose had a interesting idea. So he built a speaker to solve that one idea. Did not solve all the rest. There is a reason that design went away.
OK, pretty picture. What are you saying? You can draw?
If you really love the messed up imaging, you can add a tweeter to the front. I know someone who did that.
In truth the 301 was a far better speaker. But for the cost of their fancy vane, they could have put in a better tweeter.
If you really love the messed up imaging, you can add a tweeter to the front. I know someone who did that.
In truth the 301 was a far better speaker. But for the cost of their fancy vane, they could have put in a better tweeter.
Thanks freddi, these are definitely easier on the eyes 🙂
Very useful data, and the EQ makes them very usable.
yes, definite combing there ... but I see many respected cabinets with, say, 2 midrange or 2 tweeters were there is combing by definition (not that strong, certainly) and none takes the heat Bose does.
What many ignore/forget, is that they are typically comparing an anechoic chamber or gated measurement "regular" speaker curves with those of Bose which by definition (hint: reflected sound) are taken in a reflective room.
Once a "standard" speaker cabinet is measured in a regular room and at typical listener distance, BOTH will have terrible looking peaks and troughs.
Bose speakers are not bad at all: reasonable magnet (as large as can fit anyway), aluminum ribbon voice coil, a good light curvilinear cone, foam edge, not too different from a modern Faital Pro 4" midrange unit and similar results.
Not bad for a 40-50 y.o. design.
And besides specs, reflected sound does have a thing about it, it definitely sounds more "spacey": regular point source speakers are easier to spot with eyes closed any day of the week.
Didn´t measure my high power cone tweeters yet, will do one of these days.
In any case, they were not made for Hi Fi but as loud HF units for keyboard, PA or Bass cabinets, and they work very well in that realm.
I used a 3" (76 mm) magnet, slightly smaller than Bose´s which I estimate in 3.5", of course going next size 4" (102 mm) would make it impossible to front mount.
I used a 19mm and much lighter coil instead of Bose heavier 25mm, also a light rigid proper tweeter cone, because I had no intention of getting any Bass or even low mids so mine reach much hig[her.
It´s not me who will flame you 😉
I had the same experience.
In 1983 elections the favourite vice President candidate from the "always winning" Peronist Party lost by landslide, and had to go through ALL Buenos Aires political subsections (52-54 of them) to "explain" defeat. He needed a very small voice only PA system which would fit his car trunk so as not to be too conspicuous and which could be set up in 15 minutes tops. I supplied a 2 x BOSE cabinets, a small mixer and a Crown power amp (we are talking the 80´s here).
Sound quality, specially speech quality was very high.
Not surprising given the response curve.
In fact, in large halls I did NOT use the Bose EQ, which gave me more available/useful power in the voice band, go figure.
There is a point in favour of NOT splitting voice band smack in the middle of it, say between 500 and 800Hz, yet every single 15" + horn cabinet out there does hat.
I sold a lot of "voice clarity packs" to Rock venues around Buenos Aires: 2 - 8 x 6" speaker columns (one each side of the stage) working from 500Hz to 5kHz plus a matching crossover and power amp.
Club owners didn´t believe in the concept: "I already have PRO full range cabinets" .... until they heard them that night with a band playing ... I simply turned them ON-OFF and difference was astounding.
Back in the day, I remember several bands using 901's facing the audience as vocal only PA. Worked OK as back then we did not have affordable compact PA speakers. Besides a DC300 was indestructible and you did not need to carry a spare. Some use a Heresy instead of the Bose.
But a small venue PA for voice is not the same as a home stereo or HT, and we have learned a little since 1960. Does the word "imaging" mean anything to you? Bose was only claiming a more even frequency response in a wider listening area. Don't gat me started on the low end distortion! Boosting bass is always the wrong thing to do.
But a small venue PA for voice is not the same as a home stereo or HT, and we have learned a little since 1960. Does the word "imaging" mean anything to you? Bose was only claiming a more even frequency response in a wider listening area. Don't gat me started on the low end distortion! Boosting bass is always the wrong thing to do.
Not exactly Bose 901, but this thing https://www.diyaudio.com/community/...-little-full-range-driver.379277/post-6884821 based on this principle http://elias.altervista.org/html/SingleSpeakerStereo.html works really well and could be built into one Bose 901-like box including a mono bass unit.
Sorry forgot the title.
- My stab at a modern version of a 901 🙂
I like speakers with a broad dispersion - they typically produce a more faithful reproduction of a concert hall than the ordinary pin-point monsters.
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That is very detailed report poseidonsvoice, thanks.
Something measuring so badly can not sound good.
I heard the speakers many times in the past, never liked what I was hearing.
But others seems to like them, its ok with me.