[medium jim]

With all the choices right now, what are the upsides and or downsides of the various types of amplification for great bass reproduction?

Jim

[JohnR]

I think the key points are firstly power output, and secondly reliability when driven hard. Not all amps with supposedly similar specs are equal. I have a Behringer A500 that went a little haywire when pushed hard, several people other than me saw the woofers going into low frequency oscillation when I pushed the amp driving OB woofers at a GtG, so I'd add to the above that if you're going to spend money on an amp that needs to generate power, get a good one.

As a result of the above I finally put a low-noise fan in my QSC PLX-series amp and the fan is not audible at all, to my surprise. What I learned here is that if you have an amp with a noisy fan, just replace the fan as it might just be the bearings on the fan that are the problem.

The situation has changed a little with class D but honestly, not all that much as far as I can tell. I'd still go for something like a QSC GX5 if I needed another sub amp.

[poseidonsvoice]

I think the key points are firstly power output, and secondly reliability when driven hard. Not all amps with supposedly similar specs are equal. I have a Behringer A500 that went a little haywire when pushed hard, several people other than me saw the woofers going into low frequency oscillation when I pushed the amp driving OB woofers at a GtG, so I'd add to the above that if you're going to spend money on an amp that needs to generate power, get a good one.

As a result of the above I finally put a low-noise fan in my QSC PLX-series amp and the fan is not audible at all, to my surprise. What I learned here is that if you have an amp with a noisy fan, just replace the fan as it might just be the bearings on the fan that are the problem.

The situation has changed a little with class D but honestly, not all that much as far as I can tell. I'd still go for something like a QSC GX5 if I needed another sub amp.

Completely agree with John here. In addition I would look at the pro units from Samson.

Best,
Anand.

[medium jim]

When and if I decide to bi-amp my Magnepan 2.5's, I have a 40 year old BGW 500D that will go on the bass panels and the ribbons will be getting tubes....I might just have to change the fan, as it is noticible on very low passages...

Jim

[JohnR]

That's well into vintage/project territory. You can get a new Gx3 for $300.

[medium jim]

JohnR:

I already own the BGW that came out of a well known recording studio and has been serviced through out its life.   The fan wasn't a problem in the studio as it was in a console.  I've tried it by itself and it sounds good except for the hf where it gets a bit grainy.  For bass it is very nice and on the 2.5's, the panels run both the lf and mids.

The other thought was seeing if my guitar amp guru, who also fiddles with home amplification, can calm it down in the hf and use it as my summer amp. 

Jim

[JohnR]

Sure no worries. I guess the "500" means 500W per channel? Nice amp in that case.

[fredgarvin]

In my last band we replaced our Behringer PA amps with the QSC amps and it was a major upgrade in sound.

[medium jim]

Sure no worries. I guess the "500" means 500W per channel? Nice amp in that case.

The BGW 500D is around 400wpc in 4ohm and has over 3db of headroom.   It was the amp that replaced the Crown 300 in movie theaters and was commisioned for the movie Earthquake.  Only a few thousand were made and most were used for live sound reinforcement, i.e., PA's. Bass amps, and some found the their way into the studio and home.

They're overbuilt to the max. 








Jim

[jeffreybehr]

My bass amp--actually for what I call my SuperSubs--

...is a crown CDi2000, rated at 250WPC into 8, 500WPC/4, and 1000WPC/2.  It also is fancooled, but the fan never runs during normal operations.  (Had an intermitent short in one channel's wiring--that I never found--and the fan ran, noisily, then.)

I've never driven the SSWs with anything else, so I can't say that the Crown sounds better or worse than anything, but it definitely is plenty good enough.

I cut off one rackmount flange to make it fit better in a more-crowded-with-poweramps configuration but never got around to removing the other.  The black-plastic tape strips cover too-bright indicator lites.

[TomS]

I'm using a pair of old school Crown K2's (bottom right in pic) which were all the rage just a few years ago. They are bulletproof, very efficient, powerful (500w @8, 800w @4, 1250w @2), and have no fans. They also have multiple protection circuits for various faults.



For those fanatical HT types that must go below 20 hz and even into the single digits for bragging rights, note that some of the pro amps do roll off at LF's. The K2 has filters at 8hz and 30khz to keep nasties out, which is fine for my application.

[TRADERXFAN]

Anything with a fan I could hear at any level would not be on my audiophile list. -Just sayin.

I use a dayton sa1000 on 2 cht 18.2s with it. Everywhere else, plate amps.

[TomS]

Anything with a fan I could hear at any level would not be on my audiophile list. -Just sayin.

I use a dayton sa1000 on 2 cht 18.2s with it. Everywhere else, plate amps.

My K2's are driving 2 CHT 18.1's and 2 Geddes BP subs, which seems to work well with the Abbeys. I could still hear a fan on my other amp even though it was modded to run at half speed and it still ran a lot.