Amplification: what about the Bose cylindrical

[jazzdoc52]

radiator speakers? I sat in with a band that had one, and it was pretty good. It was for the guitar and vocal guy, but he said that it is good for keyboards too...anyone with any info? Thanks

[Sven Golly]

This is being discussed in another thread that's on page 1 of this forum... and has been discussed a number of times in the past.

 

Lots of ardent supporters, lots of energetic detractors. Not many folks sitting on the fence on this topic.

 

A search for Bose will lead you to lots of reading material.

[cjsm]

Well, one problem with the Bose PAS is you need two for stereo samples, which is what most piano samples are on most keyboards. If you don't have two, you'll get phasing issues. And two of these will set you back over 4 grand. Search the Bose forums for a discussion of this topic.

 

I think of the Bose PAS like I think of the Bose Wave table radio, good, but way over priced. Bose charges $450 for a $75 table radio, and I think the same thing applies to the PAS. They'd sell a lot more if they charged a more realistic price for them. But that's not the Bose way.

[soundscape]

Originally posted by cjsm:

I think of the Bose PAS like I think of the Bose Wave table radio, good, but way over priced. Bose charges $450 for a $75 table radio, and I think the same thing applies to the PAS. They'd sell a lot more if they charged a more realistic price for them. But that's not the Bose way.

The stereo/mono thing is extensively discussed in another recent thread here.

 

Bose stuff IS typically overpriced, though perhaps not more so than other "lifestyle" products--but the Wave Radio is a lot better than an $75 radio. (It is ridiculous (in Europe,) though, that it can't receive Digital Radio. (DAB.))

[soundscape]

Originally posted by Sven Golly:

Lots of ardent supporters, lots of energetic detractors. Not many folks sitting on the fence on this topic.

I remember using a forum many years ago where every time someone would post a message offering their Bose speakers for sale (there was a specific section for selling stuff, so that was OK), and someone would always reply with "Bose sucks" and a long debate would ensue.

[Dave Horne]

I will add this re Bose speakers (and I own two 802s), you never see anyone selling them second hand - people buy them and hold onto them.

 

(Of course, on the other hand, you rarely see Bose for sale in music stores, most musicians do not buy Bose - they are more aimed at the commercial market me thinks.)

 

I always hear that Bose products are expensive but I do give them credit for innovation - the satellite speaker system (two very small main speakers and one or two subs) was introduced by Bose. I bought Cambridge Soundworks because of the price but everyone else copied Bose's idea.

 

I can well imagine after five years or so Mackie and the other big names will be offering their own verision of the PAS system. I still haven't seen one or heard one.

[resigned]

I've posted this some time ago (re:Bose) and hoped someone would pick up on it, but since noone has I guess it's worth a repost...

 

Since this is a keyboard forum, the most important thing about a speaker system IMHO is it's ability to reproduce sound frequencies evenly. This is far different from guitar speakers or even vocal PA's and is more like a studio monitor. It means using less EQ to get a balanced sound so that all the frequencies of the keys come out as evenly as possible.

 

In the days when the powered JBL EON's first came out I was using a set of Bose 802's with their matching monster subwoofer, and a friend challenged me to A/B the EON's next to the Bose and run pink noise through them both and use an analyzer to see which produced a more even response. We did the test in my front yard which was out in the country. To get an even response from the Bose took lots of EQ and was barely possible... to get a flat response from the JBL's took practically no EQ at all. This is why you never see Bose speakers used in a studio setting. I immediately sold my Bose and have used EON's ever since whenever a PA was required... no regrets, great sound and total control over the EQ when adjusting for the room's audio deficiencies rather than the speaker's.

 

In a later test we tried the same experiment with top-of-the-line Peavey PA speakers versus JBL EON's and got similar results: the Peaveys required a lot of EQ to come close to flat but the JBL's required none.

 

It would be nice if someone tried this simple unbiased test with Bose PAS - simply run pink noise through them and see how much EQ it takes to get a flat response. Outdoors is best where room acoustics and other reflective surfaces do not interfere. It's also easy to confirm my findings with JBL EON's while you're at it if you have a pair. If it takes a lot of EQ to get a near-flat sound with the PAS then imagine compounding that EQ to compensate for room acoustics.

[Dave Horne]

The Pro, I have played CDs through my 802s (classical and jazz) and have run many different keyboards through them as well. While I can not personally vouch for their flatness or lack there of, everything sounded excellent through them - including vocals. (I assume you tested them using the System Controller? The System Controller, an eq, is an integral part of the system.)

 

I am curious to know the deficiencies you discovered in those pink noise tests.

[soundscape]

Originally posted by The Pro:

I've posted this some time ago (re:Bose) and hoped someone would pick up on it, but since noone has I guess it's worth a repost...

 

Since this is a keyboard forum, the most important thing about a speaker system IMHO is it's ability to reproduce sound frequencies evenly. This is far different from guitar speakers or even vocal PA's and is more like a studio monitor. It means using less EQ to get a balanced sound so that all the frequencies of the keys come out as evenly as possible.

Flat frequency response is important for an 'uncoloured' sound but there are many other factors. (For example, cone breakup, which may not get noticed using 1/3 octave measurements.)

 

In the case of sound reinforcement, the big problem is having a sound that is consistent across the space (coverage), and the other problem is the 'direction' from which the sound is percieved; a single stereo pair means the sound will 'collapse' into the nearest speaker if the listener is not centrally positioned, which is quite disconcerting since it doesn't match the visual cues.

 

While mega-budget systems use flown arrays etc., these problems are supposed to be addressed by the Bose PAS system.

 

Originally posted by The Pro:

In the days when the powered JBL EON's first came out I was using a set of Bose 802's with their matching monster subwoofer, and a friend challenged me to A/B the EON's next to the Bose and run pink noise through them both and use an analyzer to see which produced a more even response. We did the test in my front yard which was out in the country. To get an even response from the Bose took lots of EQ and was barely possible... to get a flat response from the JBL's took practically no EQ at all. This is why you never see Bose speakers used in a studio setting.

Don't the 802's use a digital EQ system?

 

Bose has often had a rather odd approach to audio. The 901 (which in various revisions has been sold for nearly 40 years) has most of its drivers on its rear side. I recall reading somewhere that flat frequency response was not considered that important by Bose. On the other hand JBL is all about having a flat power (room) response.

[Jazz+]

Speakers are not for playing pink noise. People use Bose 802s because they want a good sounding midrange. They sacrifice some highs and lows for that mid range, in my opinion. I would use 802s myself if I didn't feel I needed to carry an amp, the processor and a subwoofer to make it all work.

[resigned]

In response to the above:

 

Yes, I did have/use that Bose 802 controller/processor box with my system.

 

I used the Bose 802 system initially because I thought it sounded pretty good and it was portable (except for that damn heavy subwoofer), but the pink noise/analyzer test showed me a frequency response that was all over the place (I don't remember the exact results except that even using radical EQ settings I could not make it flat). Car stereos are often the same - they sound pretty good but are nowhere near flat response. Certainly most people don't actually listen to a stereo or PA system that is set for a flat frequency response but rather EQ to taste. My point is that IMHO keyboards sound best when evenly amplified across their frequency spectrum so that certain notes don't stand out way more than others due to cabinet or speaker resonance. That leaves room resonance to deal with, which is what EQ should be used for. If you're trying to use EQ to compensate both for your PA's frequency deficiencies and the room's acoustics then it's double trouble. I was impressed that the JBL EON's had such an even frequency response, which logically means that less EQ will be needed to get the desired results. And I know from years of using them that indeed I get a good balanced keyboard sound from my EON's with very little EQ.

 

I also agree that cone breakup is another factor to consider, which is another strike against Bose. Anytime small speaker have to reproduce both high and mid-to-low frequencies at the same time then it's logical that the vibration of the speaker cone is going to distort the high frequencies. This is harder to determine with commonly available test equipment, unlike the pink noise test I suggested.

 

It all comes down to taste but Bose has always had a "black box" approach to sound (like that puzzling box necessary for the 802's)... like their technology is too complex for ordinary consumers or musicians to understand. I like technology that makes sense.

[kanker.]

Originally posted by Jazz+:

Speakers are not for playing pink noise. People use Bose 802s because they want a good sounding midrange. They sacrifice some highs and lows for that mid range, in my opinion. I would use 802s myself if I didn't feel I needed to carry an amp, the processor and a subwoofer to make it all work.

Sorry, but for piano/keys, good sounding midrange just does not cut it. Give me a full spectrum, or give me death! (well, ok, maybe not death, but...)

 

I said this in another thread - tho Bose are small. I need to move large volumes of air.

[mate stubb]

Pro,

 

Which EONs are you using?

[Dave Horne]

Originally posted by kanker, apparently:

Originally posted by Jazz+:

Speakers are not for playing pink noise. People use Bose 802s because they want a good sounding midrange. They sacrifice some highs and lows for that mid range, in my opinion. I would use 802s myself if I didn't feel I needed to carry an amp, the processor and a subwoofer to make it all work.

Sorry, but for piano/keys, good sounding midrange just does not cut it. Give me a full spectrum, or give me death! (well, ok, maybe not death, but...)

 

I said this in another thread - tho Bose are small. I need to move large volumes of air.

There are eight 5 inch drivers in each enclosure. To compute the area of a circle you take pi (3.14) and multiply that by the square of the radius. The radius is half of the diameter of a circle, right? A 5" speaker has a 2.5 radius.

 

3.14 x 2.5 x 2.5 = 19.625 (area of one speaker in sq inches) x 8 speakers = 157 square inches

 

one 12" driver 3.14 x 6 x 6 = 113 sq inches

 

It would appear that eight 5" speakers would move more air than one 12" speaker.

 

I have never felt cheated in bass response from the Bose. I worked with a guy who would use two 802s for his upright bass in a big band. It sounded great. (For what it's worth, Bose states that the freq response for the 802s Series III is 55 to 16k hz ± 3db. I don't have test equipment to verify that however.)

[Jazz+]

Pink noise and math aside, I was playing a Yamaha P90 Split of piano/bass through a new pair of 802s plus processor. The power amp was a dual channel Stewart PA1000 : 250 watts per side into 8 ohms. There was no significant bass response with the bass. It was almost inaudible. The tech representing Bose told me the Stewart PA1000 amp with 250 watts per side was the reason there was no bass. He also said I needed a sub and I beleived him.

[kanker.]

Originally posted by Dave Horne:

[]There are eight 5 inch drivers in each enclosure. To compute the area of a circle you take pi (3.14) and multiply that by the square of the radius. The radius is half of the diameter of a circle, right? A 5" speaker has a 2.5 radius.

 

3.14 x 2.5 x 2.5 = 19.625 (area of one speaker in sq inches) x 8 speakers = 157 square inches

 

one 12" driver 3.14 x 6 x 6 = 113 sq inches

 

It would appear that eight 5" speakers would move more air than one 12" speaker.

 

I have never felt cheated in bass response from the Bose. I worked with a guy who would use two 802s for his upright bass in a big band. It sounded great. (For what it's worth, Bose states that the freq response for the 802s Series III is 55 to 16k hz ± 3db. I don't have test equipment to verify that however.)

I never settle for a 12", 15" and a horn is the minimum, and a 15" is 176.625 sq ins.

[Dave Horne]

Originally posted by Jazz+:

Pink noise and math aside, I was playing a Yamaha P90 Split of piano/bass through a new pair of 802s plus processor. The power amp was a dual channel Stewart PA1000 : 250 watts per side into 8 ohms. There was no significant bass response with the bass. It was almost inaudible. The tech representing Bose told me the Stewart PA1000 amp with 250 watts per side was the reason there was no bass. He also said I needed a sub and I beleived him.

One possibility for the poor bass response is this - on the Bose Series II, the output XLR Pin 2 is minus and the XLR Pin 2 input on the amp is positive. Before there were standards on the wiring on XLR plugs, Bose had Pin 2 being minus. If you use 1/4 jacks (either TRS or just TS it won't matter), you'll hear a difference if XLR cable were originally used. It's possible you were listening to the Bose Series II out of phase - that would certainly explain the poor bass response.

 

I used to use XLRs between the System Controller and the amp but wired them correctly (for each piece of equipment). I now use 1/4 cables since the length between both units is so short; a balanced connection won't offer any audible benefit (especially on a job) when the cable length is only several feet long.

 

Go back to the store and see if they used XLR cables or 1/4". If they used XLR cables it's most likely they did not have Pin 2 reversed at one end.

[Still Learning]

Originally posted by Dave Horne:

3.14 x 2.5 x 2.5 = 19.625 (area of one speaker in sq inches) x 8 speakers = 157 square inches

 

one 12" driver 3.14 x 6 x 6 = 113 sq inches

 

It would appear that eight 5" speakers would move more air than one 12" speaker.

Dave, a couple of mistakes:

First, speakers are cone shaped, not circular, you need to use equations for cones which will produce different surface area answers.

 

Surface area of a speaker (or speaker array) is independent of the volume of air that can be moved. The volume of air moved depends on the surface area of the diaphram and the throw (back and forth action) caused by the voice coil, and whether the speaker(s) are open or sealed, the overall wattage ratting, etc.

 

2 different speakers with exactly the same conic surface area could possibly move drastically different amounts of air given the exact same audio signal.

[Dave Horne]

Still Learning, so, from what you've said it's even possible that eight 5" speakers could move even more air than one 15" speaker?

 

If we can not compare apples with apples, we'll just have to reply on the frequency response, right? We should not then make any mention of the size of the driver(s), just the frequency response.

 

(I already stated the published frequency of the Series III.)

[resigned]

Originally posted by mate_stubb:

Pro,

 

Which EONs are you using?

In one restaraunt that I play weekly they have two of the original EON 15's mounted on shelves for stereo (they used to belong to me... those are the ones I did the A/B test with I mentioned previously). At other gigs I use a pair of EON10 G2's either with or without the matching powered EON subs depending on the volume needed.

[Still Learning]

Originally posted by Dave Horne:

Still Learning, so, from what you've said it's even possible that eight 5" speakers could move even more air than one 15" speaker?

Absolutely correct

 

Originally posted by Dave Horne:

If we can not compare apples with apples, we'll just have to reply on the frequency response, right? We should not then make any mention of the size of the driver(s), just the frequency response.

not exactly "right" in my book. We can compare "apples-to-apples" W.R.T. moving air using different speakers. It's as simple as measuring SPL given the exact same stimulus to 2 different speakers.

 

For my ears at least, moving air and high SPL's are not what is most important.

 

The Sound is what is most important

 

To my ears I must admit that many of the Bose products make digital pianos sound pretty darn good!

[mate stubb]

A lot of people have made points that I agree with:

 

- I have enjoyed Bose on occasion for moderate volumes. They are smooth across the spectrum that they reproduce, because there are no crossover phase shifts, frequency dips between speakers, or phase cancellation points.

 

- I have also noticed the high frequencies breaking up on Bose when you try to get loud with them.

 

- Bose and other full range cone systems sound better up close - they don't project well in large rooms.

[Griffinator]

Actually, the easiest way to determine how much air a given speaker is capable of moving is to compare its SPL.

 

Bose 801 Series III: 91dB/1W/1M

JBL JRX115 2-way 15" PA speaker: 98dB/1W/1M

 

Knowing what we know about signal levels (double the wattage to increase volume by 3dB) you're basically looking at 2.67x the power requirements for the Bose to generate the same volume output as the JBL - and that's a SINGLE speaker versus the PAIR of Bose.

 

Granted, if you're just playing piano by yourself, the Bose probably does fine in a lounge. If you're playing a 250 seat club, filled to capacity, you'll blow those Bose apart before you get them to fill the room, where the JBL's will be barely breathing heavy.

[Griffinator]

Oh - and just in case you were wondering:

 

The aforementioned JBL's max SPL output (again, per speaker) is 120dB. The Bose 802 package, based on published power handling, is only theoretically capable of outputting around 114dB at 240W power input (91:1, 94:2, 97:4, 100:8, 103:16, 106:32, 109:64, 112:128)

 

Yepper. For $2000, I can get 2 JBLS, a stout amplifier, and a modest mixer, or I can get a pair of speakers from Bose with a convoluted EQ just to make them sound good, and get less overall output for my trouble.

 

Not a difficult choice, IMO...

[ewall08530]

One thing that constantly gets overlooked in these discussions is monitors and the ability to hear yourself. How many musicians reading this have had regular trouble either hearing their keyboards or hearing their vocals loud enough?

 

Ok, you can put your hands down now.

 

With my Bose L1 I have no monitors to fight with and I can hear everything I play and sing perfectly.

 

The Bose PAS (L1) probably isnt meant for all applications but for what I've been using it for it's a pure delight to play through. Ewall

[kanker.]

Originally posted by ewall08530:

One thing that constantly gets overlooked in these discussions is monitors and the ability to hear yourself. How many musicians reading this have had regular trouble either hearing their keyboards or hearing their vocals loud enough?

I've never had problems hearing my keys EXCEPT for the couple of times that I have had to rely on the monitor mix to hear myself instead of my own rig.

[kanker.]

Originally posted by Griffinator:

Actually, the easiest way to determine how much air a given speaker is capable of moving is to compare its SPL.

Indeed. Thanks for reminding me of something I should have remembered for myself.

 

I used to use that very concept to my advantage when I had a van. I had a couple of Peavey PA speakers that would do about and SPL of about 100db @ 1w 1m. Well, the back of the van wasn't much more than a meter, probably 2 tops, right? So I'd hook the cabinets up to a 15w boombox and have a system that was louder'n all get out. Those were the days...

[soundscape]

Originally posted by Griffinator:

Oh - and just in case you were wondering:

 

The aforementioned JBL's max SPL output (again, per speaker) is 120dB. The Bose 802 package, based on published power handling, is only theoretically capable of outputting around 114dB at 240W power input (91:1, 94:2, 97:4, 100:8, 103:16, 106:32, 109:64, 112:128)

There's a faster way... use dB = 10 log P1/P2

 

Therefore Max. SPL = (10 log 240/1) + 91

= 114.8 dB

 

(The faster 'ballpark' method is 10x the power = increase of 10dB.)

 

However the real limit is not the power handling which usually relates to the thermal power (since speakers are inefficient a lot of heat has to be dissipated, or they'll melt... hence the use of 'space age' materials such as Kapton in high-end speakers), but the MECHANICAL limit, i.e., peak cone excursion before damage.

 

 

I doubt you'd be getting 120dB full range out of the JBL.. that's the job of an 18" subwoofer.

 

For example:

 

http://www.jblpro.com/pub/obsolete/4645b.pdf

 

At 800W output = 128dB at 1m assuming no power compression.

 

However max. power compression at 800W = 3.3dB. Hence 'real' output is more like 125-126dB.

 

And the 4645B uses the 2242H which is one of the best drivers made by JBL with 2" of peak-to-peak excursion before physical damage. In fact the high end JBL drivers are among the best drivers made by anyone. Whereas the JRX 115 uses the 15" M115-8A which is... well, I've never heard of it but let's say... almost certainly not.

 

 

Originally posted by Griffinator:

Yepper. For $2000, I can get 2 JBLS, a stout amplifier, and a modest mixer, or I can get a pair of speakers from Bose with a convoluted EQ just to make them sound good, and get less overall output for my trouble.

 

Not a difficult choice, IMO...

Depends on the coverage offered by each... goal is consistent output over an area... not super-high in one place to get it loud enough in another. (Of course a pair of 802's are not likely to be ideal for this, either.)

[Griffinator]

Point being, that for the same money, you get a lot less out of the Bose. If we're just talking speakers alone, I'll take the JBL Dual-15 mains ($480 apiece at Musician's Friend), a pair of EON single-15's for side-firing monitor duty, and still have change left over.

 

Granted, it's not as portable, but for my money...