Amplification Quandry

[Byrdman]

Originally posted by Jazz+:

"So, using one 12" speaker against eight 4.5" speakers, the little guys have more surface area"

 

I thought it wasn't about the cumulative surface area but about the actual diameter of the driver itself in relation to the physical width of the low frequency waveform. You still have a bunch of 4.5" diameters versus a 12" diameter. A 12" driver provides ~ 3 times wider waveform accomidation.)

Actually if you want beaming, a number of smaller cones spread out is better. For shear SPLs what matters is the product of the surface area and the voice-coil throw. So if you just scale everything up, SPLs would go up as the cube of the diameter. But of course, they don't - speakers come in a wide variety of throws and there's even lots of 15" cones out there with very little throw since they figured they could get away with it.

 

That's why the long throw SRM450's can keep up with much bigger speakers.

 

In general you are better off with a number of small speakers than one big one if the cone throws are the same because cone breakup will be less of a problem.

[davinwv]

Originally posted by Byrdman:

Anybody using those FBTMaxXs? Only 35.2lbs!

I am using their little brothers, the MaXx2As (10' woofers). They sound fantastic. the best cabinets I have ever played keys through!

[lowerhodes]

Thank you all for your responces. Jazz+ - nice comparison layout! LegatoBoy - I used to have a BBE Sonic Maximizer in my guitar rig and acheived a subtle change that I would say was an improvement. It had to be dialed in very sparingly. I abandonded it in the interest of simplicity but I may try it on my keyboard rig. I was talking to a guy yesterday (local pro)who said he now uses a pair of Barbetta Sona 31's. I've never even seen one. Anybody have any experience with them?

[Dave Horne]

re Bose 802s ...

And didn't they change the foam around the drivers becuse it was wearing out?

I wrote to Bose years ago about this and gave them my serial numbers. They couldn't give me specific information about my speakers. Mine are about 15 years old and I opened up the front grill yesterday and they're fine. The 'problem' you're referring to goes back _many_ years.

 

The 'foam' on my speakers looks more like fibre paper so I assume I won't have that problem. One set of speakers has a brown 'foam' ring and the other a black ring, but both look fine.

 

Has anyone here traded up from the Series II to the Series III ... and can you hear any improvement?

[JeffLearman]

Mine are original series. I replaced a number of the drivers before I found a re-surround kit.

 

While the "controllers" (which are just EQs tuned to the inverse of the frequency response of the cabinets) vary from model to model, they're interchangeable since the drivers and cabinets have the same audio characteristics -- they simply improved or changed the circuitry over the years.

 

Only the original Bose had the foam surrounds that decay. Starting with the II's, it's a linen surround. That's the main difference between the originals and II's. I don't know what the specific difference is for the III's, and I'd be interested to hear what anyone has to say about that. The III's use identical drivers as the II's.

 

BTW, there's also a run of 802's that preceeded my originals, and they're shaped differently than the rest of the series. I've seen 'em on ebay. Not sure the exact designation, but the sides aren't parallel like they are on all subsequent models.

[delirium]

Originally posted by dementedchord:

jazz+... no it really is the total surface area... and the 8 little ones can be seen as a single piston...(linear motor)

I don't agree, you can fake big speaker with many small ones but it never be the same. I've tried once to use such setup didn't work. For good piano sound speaker has to be bigger then 12"

[Dave Horne]

For good piano sound speaker has to be bigger then 12"

Not true.

 

I've been using my 802s for about 15 years and the piano sounds great through them - and I'm pretty fussy. As I wrote earlier, a bass player friend of mine used two 802s for big band rehearsals and those little tiny speakers sounded just great.

 

I've played all kinds of music through my 802s, classical CDs, jazz, you name it and the speakers sounded natural, nothing was lacking.

 

The stated frequency response for the Series III (I have the Series II) is 55 - 16K, ±3 dB. That's pretty damn flat for a speaker.

 

I'm not going to say I'm an audiophile, trust me, but they really do sound good.

 

I'm always curious why more musicians do not buy Bose. Is it that they are priced higher than the competition? A new 802 sells for about $750. Times that by 2 and you're up to $1500 just for two 802s ... and we still haven't added the system Controller. mixer and an amp. Is it just the high cost that prevents more from being sold?

 

I have to honestly admit, whenever I walk into a music store I never see any Bose speakers set up. Are these made more for commercial use?

[jazzdoc52]

Great Thread! What do you guys think about using a roadbox III and the straight Roadbox as a stereo set up? I already have a Nord 73 and am purcahsing a Yamaha 290es for my piano sounds.

[jazzdoc52]

Great Thread! What do you guys think about using a roadbox III and the straight Roadbox as a stereo set up? I already have a Nord 73 and am purcahsing a Yamaha 290es for my piano sounds.

[WWW]

Another cool altervative for a keyboard PA style amp: PUB 380 : ACTIVE LOUDSPEAKER & BASS SUBWOOFER

 

http://www.schertler.com/prodotti_ing/loudspeakers/pub280380.htm

 

 

or, a bit smaller:

http://www.schertler.com/prodotti_ing/loudspeakers/unico.htm

[JeffLearman]

delerium, there is another factor. The little speakers have to be close enough together and mounted so as to be reasonably phase coherent. If you do it right, it's total area that governs bass response, not diameter or single cone size.

 

This trick is used extensively in what's called "phased array" technology, which is not just used for audio but also medical purposes. In that case, they have lots and lots of very small drivers and can shape the wavefront -- even making it act as though there was a lens.

 

Good point, wdl, subwoofers are another way to get good bass response, and without the sacrifices we make in clarity and punch with 15" drivers.

[dementedchord]

one thing i didn't mention earlier about using multiple small drivers is the excursion of course contributes to the shear amount of moving air so it's not always easy to compair the two... and they (the 802) tend to be mid rangy which is not necessarilly bad for our use... always been a saying around sound men..."no highs... no lows... must be bose..."

[Legatoboy]

Lowerhodes,

 

"I was talking to a guy yesterday (local pro)who said he now uses a pair of Barbetta Sona 31's. I've never even seen one. Anybody have any experience with them?"

 

I have a Barbetta Sona 32 Elan (newer Sona 32) that I will be putting up on Ebay shortly. That model is alittle too bass heavy (15') and horn under powered in terms of the drivers for me.

 

BUT the Bi-Amp set up in those amps (Sona series) rock, they get loud and don't distort and they are lightweight and are pretty cool amps. Alot of people prefer the 31 , 41's over the 32's. The 41 being the most preferred I think.

 

If you get Tony Barbetta on the phone he can be very accomodating and you can get his "cool man" rap, that's sounds pretty cool in that 'old hipster california drall kinda way too!

 

"Cool Man",

lb

[MikeT156]

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For good piano sound speaker has to be bigger then 12"

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Reply by Have Horn:

 

Not true.

 

I've been using my 802s for about 15 years and the piano sounds great through them - and I'm pretty fussy. As I wrote earlier, a bass player friend of mine used two 802s for big band rehearsals and those little tiny speakers sounded just great.

 

I've played all kinds of music through my 802s, classical CDs, jazz, you name it and the speakers sounded natural, nothing was lacking.

 

The stated frequency response for the Series III (I have the Series II) is 55 - 16K, ±3 dB. That's pretty damn flat for a speaker.

 

I'm not going to say I'm an audiophile, trust me, but they really do sound good.

 

I'm always curious why more musicians do not buy Bose. Is it that they are priced higher than the competition? A new 802 sells for about $750. Times that by 2 and you're up to $1500 just for two 802s ... and we still haven't added the system Controller. mixer and an amp. Is it just the high cost that prevents more from being sold?

 

I have to honestly admit, whenever I walk into a music store I never see any Bose speakers set up. Are these made more for commercial use?

-------------------------------------------------

 

Dave:

 

12" speakers can be "adequate" but for rock you really need to have 15" speaker. The 802's are very good as a set of PA speakers or in your case, they would work ok, you don't play loud. 15" inch speakers can typical play lower notes than a 12" speaker.

 

The 802's are expensive for what they are. You can get a set of EAW 3 way speakers, with a 15" bass speaker for under 800 bucks each. EAW's are top quality speakers, and full range speakers that can handle a lot more power than 802's.

 

802's are OK for some applications, but they wouldn't be a good choices to run KB's through, especially when you factor in the high cost compared to other speakers these days.

 

 

Mike T.

[Dave Horne]

Dave:

 

12" speakers can be "adequate" but for rock you really need to have 15" speaker. The 802's are very good as a set of PA speakers or in your case, they would work ok, you don't play loud. 15" inch speakers can typical play lower notes than a 12" speaker.

 

The 802's are expensive for what they are. You can get a set of EAW 3 way speakers, with a 15" bass speaker for under 800 bucks each. EAW's are top quality speakers, and full range speakers that can handle a lot more power than 802's.

 

802's are OK for some applications, but they wouldn't be a good choices to run KB's through, especially when you factor in the high cost compared to other speakers these days.

 

 

Mike T.

I agree that a 15" speaker can play lower frequencies than a 12" speaker. what does that have to do with the music I play?

 

I should add that my 'home stereo' speakers (Cambridge Soundworks) have two 8" subwoofers and they sound great for home stereo.

 

__Any__ measurement of __any___ speaker involves a 'frequency response' - a frequency range coupled with a deviation from 0 dB. The Bose Series III are advertised as being 55 to 16K ±3 dB. Stating 'numbers' without a reference says nothing.

 

'loud' ...??? ... define in decibels.

 

'handle a lot more power' says nothing. The Bose speakers are very inefficient but my amp puts out 550+ wpc. Your point?

 

Any audio engineers who can jump in and help out?

[WWW]

I have to respectfully disagree with Mr. Horne, and agree with with Mr. Fortner's latest review on amp set ups in this month's Keyboard, where he describes beautiful results using 2 AccuGroove T112L's. No boomy 15's there. Just excellent accoustics using 12" woofers. This is consistent with my own hi fi experience (and my use of the same AccuGroove cabs), where almost no apeakers use 15's - just too difficult to control, and significant downside in reproducing the critical midrange, where most of the music resides. Good news for us. !

12's are lighter, and easier to drive...

and sound better...