Plate amps vs Inuke or Crown

[jason str]

PEQ is a great tool but make sure it is a good one, some of these that come with cheap amplifiers sound really poor. Hook the amplifiers up to the mains first to get an idea of how they sound, if it sounds poor hooked up there its not doing the subwoofers much justice.

 

You spend countless hours deciding what subwoofer design and driver to compliment, even more time with proper placement and room treatments it makes no sense saving a bit using a budget amp with built in PEQ just to have it.

 

I'm not saying to go crazy buying the best high end model just that it does matter.

[MikeFord]

Apart from SQ, the idea of a metal plate as a physical part of my speaker cabinet annoys me, putting all the amp bits inside the cabinet seems even worse. The other non SQ issue I have is access to the controls, as a likely spot for a sub, where my current sub is located, has the controls buried in the corner to allow the woofer to face out in the room.

 

Third non SQ issue, Calif electric rates, I pay close to $0.30/KWhr, so I want close to zero power when off, and as high of efficiency when running as I can get.

 

Forth non SQ issue is flexibility with several different subs, why put an amp in each one instead of a Speakon jack?

[Maz4bz]

Hi there,

I have built 10 subs over the years, some using plate amps.

 

I don't use plates anymore and have switched to Crown XLS 2500's for my current HiSAF Sub pair I'm running.

 

The reason for this is a bit of a journey. Bear with me...

 

Initially I ran these subs from a Rotel RB-1092 using the crossover in my pre-pro. This amp is rated at 500w RMS into 8ohms, my subs are 4ohms so I figured plenty of headroom because the amp would be outputting up to double that theoretically into that load right?

 

So after watching a review by Andrew Robinson I figured I'd try an XLS 2500 for my new subs. I inserted this into the place of the Rotel running one sub per channel, fired up one of my favorite extreme bass blurays - Tron Legacy's welcome to the grid chapter when Flynn first enters the grid and promptly gets arrested -  only to find the Crown was immediately running its front lights up into the clipping zone on the front panel. I couldn't turn down the volume fast enough!

 

Now the XLS 2500 puts out 775w rms into 4ohms per channel so its a bit less powerful than the Rotel, in that 200 watts extra output into my relatively inefficient subs is only going to reward you with a few extra db in volume/headroom. So in overall loudness there's marginal real benefit in the Rotel's theoretical extra output.

 

At this point what dawned on me was that if I was able to hit the Crowns limits so easily then probably I was also doing so with the Rotel, just that I was unable to see the amp clipping when this was happening - a potentially dangerous situation for my expensive sub's voice coils. And it seems difficult for me to hear when my sub amps are clipping in loud passages. I assume I'm either deaf (I am) or that with all the other sounds and the distraction of whats happening on screen I just don't notice?

 

So you may ask why have I stayed with the Crown? Well mainly because now I know when I'm over driving my subs visually and the pro amps have clipping limiters which I think is excellent insurance against over driving your subs amp. I also upped my available amp headroom by getting a second XLS 2500 and bridging these so I have one for each sub now - there is no such thing as too much clean power for transient headroom? 

 

The point being that no plate amp I know of has these features and so now I'm a passive sub/pro amp convert.

 

Hope that helps.

 

Oh and BTW the Crown's sound great on my KG 5.5's too.

[jason str]

I have recommended these Crown XLS series amplifiers to a few customers, the RCA inputs are great for integration of nearly any system.

[Paducah Home Theater]

On 1/18/2017 at 7:45 AM, CECAA850 said:

WOW, those look great.  I didn't realize Speakerpower made plate amps.  Built in adjustable delay and low frequency boost.

 

That's what I'm running.  Spanks the typical cheap class D's pretty badly.  Halfway want to send mine back in and have it modified to a rack mount.  

[Paducah Home Theater]

On 1/30/2017 at 4:38 PM, MikeFord said:

The other non SQ issue I have is access to the controls, as a likely spot for a sub, where my current sub is located, has the controls buried in the corner to allow the woofer to face out in the room.

 

Once it's set up, this is a non-issue.  

 

On 1/30/2017 at 4:38 PM, MikeFord said:

Forth non SQ issue is flexibility with several different subs, why put an amp in each one instead of a Speakon jack?

 

You are free to run multiple subs from a plate amp.  I'm running four 18's off of one.  The only problem is that you have no control over individual gain and delay, they all just do the same thing, which isn't good if you're spreading them out.  

[derrickdj1]

A sub amp on the inside has certain drawbacks.  The amp takes up space, heat is an issues and access to name a few.  Once you enter the world of passive subs, you may never want to go back.  As for the I Nukes, they are good amps for the value and give you unprecedented control to mate  the sub with the room.  Nothing wrong with plate amps.  I still run one, a Klipsch sub that has been going strong for some years.  It's just a matter of how much flexibility one wants in controlling things.  Speakers don't make much difference but, when it come to subs, the more control to integrate them with the system is paramount.

[Paducah Home Theater]

21 hours ago, derrickdj1 said:

A sub amp on the inside has certain drawbacks.

 

A rack mount amp has certain drawbacks as well.  Consider the wire length.  A high powered sub amp can easily lose like 400 watts by the time it snakes around a room through typical 12-14 gauge wire.  Plus there's the damping factor, which can be significantly changed by the wire.  Do the math in the article below.  Sometimes having a plate rack right next to the sub is significantly better than having the amp in a rack on the other side of the room.  

 

http://eaw.com/amplifier-damping-factor-more-is-better-or-is-it/

 

 

[derrickdj1]

2 minutes ago, MetropolisLakeOutfitters said:

 

A rack mount amp has certain drawbacks as well.  Consider the wire length.  A high powered sub amp can easily lose like 400 watts by the time it snakes around a room through typical 12-14 gauge wire.  Plus there's the damping factor, which can be significantly changed by the wire.  Do the math in the article below.  Sometimes having a plate rack right next to the sub is significantly better than having the amp in a rack on the other side of the room.  

 

http://eaw.com/amplifier-damping-factor-more-is-better-or-is-it/

 

 

 Nothing wrong with plate amps.  I still run one, a Klipsch sub that has been going strong for some years.    

 

I stated this above. The point is preference and tailoring what needs to be done in the room.  Wire distance is not a major factor for most HT's being less than 35 ft.  I would love to see you store next time I'm in Kentucy since you are kinda right next door to Indiana, lol.

[babadono]

25 minutes ago, MetropolisLakeOutfitters said:

 A high powered sub amp can easily lose like 400 watts by the time it snakes around a room through typical 12-14 gauge wire.

400 watts of loss? Please expound.

[Paducah Home Theater]

43 minutes ago, babadono said:

400 watts of loss? Please expound.

 

Use the calculator below and notice the power to the speaker with 35 feet of 12 gauge wire when running a 4,000 watt amp rated at 2 ohms, into 2 ohms, which is exactly what a SpeakerPower SP1-4000 plate amp is rated for and that happens to be exactly the length of cable I need to get to my front subs when running a rack amp .  

 

http://www.electrovoice.com/cableloss.php

 

Now change the length to "1" and see what happens.  Also notice what happens to the damping factor.  Sometimes plate amps mounted on the box is just better.  

[babadono]

1 hour ago, MetropolisLakeOutfitters said:

 

Use the calculator below and notice the power to the speaker with 35 feet of 12 gauge wire when running a 4,000 watt amp rated at 2 ohms, into 2 ohms, which is exactly what a SpeakerPower SP1-4000 plate amp is rated for and that happens to be exactly the length of cable I need to get to my front subs when running a rack amp .  

 

http://www.electrovoice.com/cableloss.php

 

Now change the length to "1" and see what happens.  Also notice what happens to the damping factor.  Sometimes plate amps mounted on the box is just better.  

Thanks for that MLO. Wow I guess I'm just used to my KHorns only needing 10 watts to drive me out of the room.

[babadono]

Too bad the cableloss calc stops at 6 AWG. Maybe some double aught would do the trick

[MikeFord]

Back in my lets try any crazy wire stage, I used some submarine battery cable, no clue on the gauge, but it was heavy, maybe a 1/3 inch in diameter of fine copper stands in each cable. Sounded nice, but I didn't keep it.

 

Some of the big bass guys I used to talk with ran Crown macrotech big amps, 1000 or so real watts, and several of them. Its one way to go, but not my choice.

 

Regards clippiing, not really much of an issue with a pure subwoofer. Heat is RMS power, clipping the waveform doesn't change the heat much. Distortion is usually both low enough and out of band so its not noticed. Musical transients start with big peaks, and few if any bass speakers don't have a MUCH more gradual output response, so you don't get the peak first output regardless of clipping (if the signal level changes rapidly, its not bass, its higher frequency components)..

[derrickdj1]

5 hours ago, MikeFord said:

Back in my lets try any crazy wire stage, I used some submarine battery cable, no clue on the gauge, but it was heavy, maybe a 1/3 inch in diameter of fine copper stands in each cable. Sounded nice, but I didn't keep it.

 

Some of the big bass guys I used to talk with ran Crown macrotech big amps, 1000 or so real watts, and several of them. Its one way to go, but not my choice.

 

Regards clippiing, not really much of an issue with a pure subwoofer. Heat is RMS power, clipping the waveform doesn't change the heat much. Distortion is usually both low enough and out of band so its not noticed. Musical transients start with big peaks, and few if any bass speakers don't have a MUCH more gradual output response, so you don't get the peak first output regardless of clipping (if the signal level changes rapidly, its not bass, its higher frequency components)..

Matt, you make a good point regarding amp distortion.  It is usually way less compared to diver distortion.  And people don't quite realize when talking about distortion for speakers, subs and amps, it is greatest approaching max power use and is not a problems at normal listening levels of 88-90 db.