Infrasonic

Favorite amplifiers for bass

91 posts in this topic

I got some open box CC5500's off ebay for $799 from an authorized dealer.  Mint.

 

I have each of them bridged powering an Othorn.  HOLY COW!

 

Nice score. 

 

I realize they're power-house amps, combined with the high sens boxes, as insane as it sounds ...  have you explored their limits? Can you describe the fans, and how they operate at idle, in normal use, when hitting it hard, etc.? What type of line side power/how are you feeding them?  Any noteworthy power related comments?   

 

On a related note, has anyone read or experienced first hand, anything worth sharing about  the ProLite, class D series from Crest? 

Share this post


Link to post
Share on other sites

I also have a Q:

 

Are the Peavey IPR2s really that good? I see them praised in many other places...

 

JSS

Share this post


Link to post
Share on other sites

Nice score. 

 

I realize they're power-house amps, combined with the high sens boxes, as insane as it sounds ...  have you explored their limits? Can you describe the fans, and how they operate at idle, in normal use, when hitting it hard, etc.? What type of line side power/how are you feeding them?  Any noteworthy power related comments?   

 

On a related note, has anyone read or experienced first hand, anything worth sharing about  the ProLite, class D series from Crest? 

 

When first powered on, the fans stay completely off for a few minutes.  Then, even without playing anything, they'll turn on at a pretty low speed.  At this point they're still more quiet than say a stock ep4000 or inuke by far.

 

I've hammered on them pretty good for a few hours and the fans have barely speed up, but it's not something you'd want in the same room.

 

Since they have the 30a twist locks, I had to upgrade the outlets, but each amp has a dedicated 30a circuit.  

 

For SQ, I can't tell any difference from my fp14k's.  They hit just as hard, sound just as clean, and running some sweeps in REW show they have the exact same response curve down to 10hz.  My horns can't play much below that, so I can't test any lower.  

 

As a power test, I had one Othorn on one channel of a fp14k clone running in stereo.  I played a heavy bass track until the clips lights were on hard.  Using my calibrated UMM-6 and REW as the SPL meter, I took note of the max SPL.

 

I then put a bridged Crest in and matched the SPL.  There was no hint of the clip lights, and the fan speed didn't increase.  Yes, an unfair test, but I wanted more power and definitely got it.  

Share this post


Link to post
Share on other sites

I also have a Q:

 

Are the Peavey IPR2s really that good? I see them praised in many other places...

 

JSS

 

 

Funny enough, this post was just made on AVS by N8DOGG:

 

"Since I've got both the 7500 and the 14 clone, i'll give my 2 cents. If your running 2 ohms, get the peavy, anything else, get the clone.

My 2 new fp14's work great, no issues so far. They do a better job than the peavy with my FTW's, they hit harder than the peavy does but I have 4 ohm drivers.

The subs just seem to really hammer with the clones and hooking up the peavy, it's not the same experience. I don't have any charts or numbers, just going from feel."

Share this post


Link to post
Share on other sites

Can anyone comment on the suitability of a QSC RMX850?

I am currently using one bridged to push my 3rd cylinder, an SVS 20-39 tuned to 16 Hz with an upgraded 12.3 driver.

 

Any shortcominings, comments or siuggestions for the RMX850

low end roll-off a limiting factor ?

Share this post


Link to post
Share on other sites

I have tried a lot of amps for my subs,doesnt like PA amps noice/dist,tried some krell amps 300cx,700fpb-cx

those have a limiter for dc so it creates "gunshot" Sound when fed like a (2 Hz) signal from HTTYD dragon crash,my new amp is no problem not cheap bit ot works ; )

Share this post


Link to post
Share on other sites

Something I have been thinking about for a long time, that may be actually possible soon.

 

I need an amplifier that can put out around 500-1000W per channel, but exhibit near zero rolloff down to 1Hz.  My house cannot take lots of ULF, as my drywall can already attest.  I was going to build a riser and install some Crowson tactile transducers under it to get the content below 7-12Hz...

 

Ideas?

 

 

JSS

Share this post


Link to post
Share on other sites

Guess you should go for a low ~16Hz tuned ported sub setup,due to house as you said,so Max you dont need to worrie about rollof at 1Hz,or did i missunderstand you?

 

Nicke

Share this post


Link to post
Share on other sites

Guess you should go for a low ~16Hz tuned ported sub setup,due to house as you said,so Max you dont need to worrie about rollof at 1Hz,or did i missunderstand you?

 

Nicke

 

I still want to use multiple sealed, but not in enough number to get super low (every octave lower requires 4x the displacement).  For the lowest octaves, which are mainly felt as a result of resonances, I want to use crowson transducers under a riser.  They turn 'sound' into 'movement' as low as the content present, so a signal chain + amplifier with zero rolloff would be preferable, as long as you put in a delay to account for the fact that the transducer is at 'zero distance' from the LP.  Basically, I want to feel the 1-3Hz hits I keep graphing.  The only person I know that can is Bosso, as he has worked diligently for years to ensure no rolloff in his signal chain.

 

JSS 

Share this post


Link to post
Share on other sites

 ^  ^  ^

CraigJohn over at AVS turned me onto Crowson transducers a couple years ago. I'm very interested and implementing them into my sub system has been my plan as well, such actuators don't get any better than Crowson's offerings. You're right, proper time delay is vital .. as is overall level. I've been in contact with other users as well, almost pulled the trigger a year ago, held off because I changed our seating a bit.

 

Why don't you contact Crowson, wrt signal path roll-off etc?  

Share this post


Link to post
Share on other sites

I neglected to mention, currently with (4)15"s and (4)18"s, I've got a lot of displacement, but the structural moans and groans are both a little un-nerving, and somewhat distracting.   

Share this post


Link to post
Share on other sites

I neglected to mention, currently with (4)15"s and (4)18"s, I've got a lot of displacement, but the structural moans and groans are both a little un-nerving, and somewhat distracting.   

 

I agree.  Seeing my front wall move 1/4" with 20Hz at 115dB is probably not good for it.

 

I will contact Crowson when I get time.

 

JSS

Share this post


Link to post
Share on other sites

Well...If you want an amplifier with zero roll off and all day long output below 20Hz you can try to score a cheap Crown M600 or AETechron 7560. These are DC coupled and will sit there and drive 2 ohms at about 1250w long term and will burst a lot more. They'll even drive 1ohm. However they are also 4 rack spaces tall and weigh 95lbs with a couple of huge fans. I had a pair I scored for like $650 years ago. Good amps just huge and back breaking.

Share this post


Link to post
Share on other sites

Quest QA4004. Australian made class G 2400W/ch/4R and about 38kg. Tough as hell and often available locally for not too bad money.

I haven't measured it but I have the full schematic and there is only one series cap with a calculated F3 of 4Hz. That's good enough for me.

I have 2 units and soon each channel will be powering a sealed FTW21 in about 300L ea.

 

The QA3004 is also a great unit and is 1400W/ch/4R with similar great build quality and about 10kg less weight.

1 person likes this

Share this post


Link to post
Share on other sites

I tried a Yamaha P3500S amp on a pair of JTR Captivators. It worked fine and I was very impressed with the amp, though it was underpowered for my application. The amp wasn't rated for 2 ohm stereo use, but it worked, and the fan never kicked on in my usage of the amp. It has a thermal turn on point of 90*C. Overall I was very impressed with the Yamaha p-s series. Build quality is among the best of any amp I've messed with. Attenuators have a satisfying solid feel, very solid all around!

1 person likes this

Share this post


Link to post
Share on other sites

Just picked up a pair of RMX-4050s, huge power, big upgrade over the EP4000.

Down side is they are not cheap and very heavy

Upside is they really deliver and for a lot less $ than a PL or itech

 

If you don't need to move your amp around too much, you can't go wrong with this thing. Got em for about $1100 each.

Share this post


Link to post
Share on other sites

Time to revive this thread.  

 

For the past year or so I've used the Crest CC series of amps and really like them.  I've been powering my subs and mains with them and can't find any fault with them other than they're heavy and the fans aren't completely silent.

 

I also recently purchased my first SpeakerPower amp.   The rack-mount SP2-12000 has fans but they only turn on if the amp starts to heat up, and that's been really hard to do.  I had to push the amp to clipping on music for over 10 minutes to get them to turn on, and even then the RPM was really low and I could barely hear them.  For a single amp running 2ohm stereo this is a hard amp to beat.  

Share this post


Link to post
Share on other sites

Oh BTW, here's some testing I did between the CC4000, CC5500, Pro Lite 7.5, and the SP2-12k on my pair of Ghorns at 15hz.  15hz is near the excursion minimum so there was no risk of bottoming the drivers.  All amps were on dedicated circuits. 

 

 

Crest Pro Lite 7.5 (120v, running in stereo):

 

15hz: Clipping at 127db (power cycles when attempting 128db)

 

 

SpeakerPower SP2-12k (240v, running in stereo):

 

15hz: Clipping at 130db

 

 

(2) Crest CC4000 (120v, one bridged per Ghorn):

 

15hz: Clipping at 131.6db

 

 

(2) Crest CC5500 (120v, one bridged per Ghorn):

 

15hz: Clipping at 132.8db

 

 

 

 

Very pedestrian testing but proved to me that all these amps in question appear to perform up to specs.  

Share this post


Link to post
Share on other sites

I've got an SP12k on hand too. I'm going to do much the same type of testing versus a k10. I'm going to use CEA2010 bursts for the short term test and very slow sine sweeps for the long term. Probably going to use dual 21Ipals for a 2 ohm load and dual XXX for a 4 ohm. Thought about wiring up 4 drivers but that starts getting to be too much to drag outside. Dual of either aught to handle a single channel of either amp.

1 person likes this

Share this post


Link to post
Share on other sites

I've got an SP12k on hand too. I'm going to do much the same type of testing versus a k10. I'm going to use CEA2010 bursts for the short term test and very slow sine sweeps for the long term. Probably going to use dual 21Ipals for a 2 ohm load and dual XXX for a 4 ohm. Thought about wiring up 4 drivers but that starts getting to be too much to drag outside. Dual of either aught to handle a single channel of either amp.

 

Looking forward to it.

 

There was one thing disappointing with the sp2-12k...the pathetic power cable it came with (14awg)!  I bought this from amazon to replace it:

 

http://www.amazon.com/Tripp-Lite-Heavy-Duty-Extension-P041-008/dp/B005KKCJRW

 

 

20141003_142644_zpskyv1jltv.jpg

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now