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Bose 901 Series V review
I just completed my review of the Bose 901 Series V. It would take me an inordinate amount of time to copy/paste it all here so to save my sanity I am sharing the link to the review on my site:
https://www.erinsaudiocorner.com/loudspeakers/bose_901_series_v/
I'm proud of this one. Lots of work and time went in to creating this. About 20 hours so far. But I learned a lot and hopefully others will, too.
And, yes, I know this is a site geared toward DIY. But us DIY'rs can't turn down knowledge of how a product performs objectively. Especially one of this... heritage.
Comments
Since I do work on those a bunch, I'd agree with everything you said. The EQ is horribly noisy, the drivers...ehh. Also, the tuning is closer to 40hz. I run tone sweeps through them and have observed the cone movement. So, yeah, ya pretty much nailed it. Funny how people into those and see them as the best don't really like anything else.
Growing up our next door neighbor had a pair of these. I didn't know anything about audio then, but I was certainly more impressed by my dad's Realistic Optimus 5 coffins, but mostly because they could shake the house better.
The audio "image" presentation is certainly unique, looking at the polar plots it appears that this speaker aims to create order out of chaos, not surprising that a sweet spot is non existent.
Holy crap that must been hours and hours measuring. I haven't heard 901s since the iv but never liked them,and now know why, really cool stuff.
Who wants to be the Guinea pig and build some with decent drivers?
Hmmm, you could make a base with a woofer/subwoofer and use an array of affordable quality Tymphany drivers...
I think if someone told me I had to recreate that I would put 2 6-8 inch drivers on the back and one good FR on the front.
If someone REALLY wants to see it done, I will build it for them (with their drivers). They will be responsible for the dsp correction. Who knows 30-40 years of driver engineering might make these sound ok.
Whether you think it's worth trying to emulate the concept of the 901s is perhaps determined by your attitude to omni-directional speakers as well as your budget and skill level. I don't have either...
One school of thought is that the 'concert hall experience' is made up of mainly reflected sound (depending where you sit), therefore your speakers should reflect (awful pun) that in their configuration. Another is that the recording mikes and the producer/engineers capture the different parts of the sound anyway and, therefore, it's already included in the final stereo recording.
Which sort if begs the question what is 'concert hall' sound? How much live music do you experience in a 'concert hall', and how much in a smaller venue or pub with sometimes awful acoustics? And if it's a rock concert, the sound is usually played through the PA, straight at the listeners.
To try and find an example, the old RCA recordings of the Chicago Symphony Orchestra really seem to me to capture the ambience of the hall, even though I've never been there, the recordings just sound 'right'. Particularly with the brass, there's a reverb and size to the horns which I haven't heard with many other orchestral recordings.
Any thoughts?
Great review, really thorough and factual, thank you.
Geoff
EPI made a direct/reflecting speaker back when. https://humanspeakers.com/e/epi601.htm
Ron
I'd say to do it sorta right, a fullrange on one side of the back, a true woofer on the other, and a coax on the front. All taylored to work together of course. Thought about it, haven't attempted it yet.
This is thinking aloud and I have no idea how to do it or how it might sound, but perhaps a VIFA TC9 and SB20pfc on the back - for the full range and woofer - and an SB16PFC coaxial speaker on the front? Even in Oz, that wouldn't be too costly price wise: about AU$150 per speaker. I think the VIFA/SB combination could work and has been tried by a few DIYers here, but the problem could be the coax: I haven't seen it used anywhere.
PS The more I think about this concept from the angle that I know next to b- - - -all about speaker design, the harder this is to work out how to do.
For example, how would you work out the baffle step on an angled back panel, and would you have to treat front and back parts as separate speakers, each with its own chamber, crossovers and input terminals? Very difficult to do, I'm sure, maybe almost impossible to do well, and would it be worth the trouble? Sorry, this is getting away from the review posted above, but having read and enjoyed, it got me thinking about the concept.
I should add that I've heard an older pair of those speakers and didn't like them much.
Geoff
My Dad has a set of these and the pro audio versions. Dsp helps a lot.
I think if someone wanted to recreate this they could use a dsp 2x4 treating the rear firing section seperate from the front. This could help with some of the timing issues as well as make the ohm load a little better for the amplifiers. I think the Bose units are 1-2 ohms each.
2 drivers per side might work better as well almost like 3 Nola Brio all back to back. This would help with the polar pattern and diffraction issues.
The rear would just need a limited bandwidth to add the reflecting "backing" info, as well as level. Also, of course its own enclosure. The front could be an open back tunnel or damped would prolly be better option.
Not sure if you guys are interested but I also am trying to create YouTube video reviews where I use my data to discuss the subjective and objective performance. Here's the one I made for this speaker:
FWIW, PE is selling a replacement driver for the 901 here:
https://www.parts-express.com/replacement-speaker-driver-for-bose-901-4-1-2-1-ohm--290-922
Look at its FR.... it's uuuuugly.
....just like the real ones. In all fairness the real ones are different. I've had 901's come in with those thrown in them, usually singles or a few.