Running tower speakers in mono

We've got a set of Wetsounds 485's to mount on our new 210 when it arrives. We've had the Defcon 3s in the past as well as our own custom set ups with HLCDs.

With the 485's we can run a lot more power than in the past. We've got a nice deal with Clarion and I'm a bit confused as to what Clarion amp/amps to run. The biggest two channel they do is 2 x 125W which is a bit light on. I was thinking of running one of these for each side so each enclosure will get 250W. Another option is to run a single channel 800W amp full range so each enclosure will get 400W.

I've never thought it overly important to run tower speakers in stereo in the past but we've never had any this powerful. The single amp seems a little easier to me but I am interested in what people think is the best way to go and if stereo is important.

No need for stereo up there.

With my 4 channel amp it's about 15 seconds to swap 2 RCA cables and go from mono to stereo. I have debated the subject with angrymike who is a recording engineer here on this webboard. He knows and expects some certain sounds to come from certain areas so he runs his in stereo. I use my tower for the rider and other far field applications, I tend to prefer mono. Having said that I honestly cannot remember weather mine is in stereo or mono at the moment? All I know is that it sounded great this afternoon at 80' out.

As suggested by Mikeski himself, I tried both and decided that mono was what I liked as far as satisfying to the rider.

I have a larger problem with phase cancellation when collapsing to mono, than I do imaging.
Most guys who ride with me are also work buddies, so we listen and talk shop all the time, and I want things sounding as accurately as possible in the boat as well.
It's all program dependent..
Many stereo recordings sound terrible in mono. The phase cancellation kills high frequencies, especially with things like guitars, etc. It varies from song, to song. If it was mixed well, there should be minimal cancellation, but that's not always the case or even avoidable. Most people don't care about that, but unfortunately I do, and most of the people who ride with me, but we are in the minority.

You will not be able to use a mono amp to push yoru tower speakers. You can run them in mono, but I think the clarion amp ( 800w) your referrign to is stricly a mono ( sub ) amp.

Thanks for the replies. From that it sounds like not having stereo wont worry me too much.

Sam - I dont quite get what you mean? Yes the amp I am talking about is a mono sub amp but if I dont turn the low pass filter on I expect it will run full range and that would be ok?

I'm not familiar with Clarion amps but if it is a mono sub amp, there is a good chance it's a class D design and if it is you don't want to use that full range.

This Clarion amp seems like a good choice:
http://www.clarion.com/us/en/products/2007/audio/amplifiers/DPX1800/us-en-product-pf_1165294762638.html

Clarion DPX 1800 (20hz-20khz)

Over the years Clarion has consistently produced good moderately priced equipment.

Nice pick Mike. That's exactly the one I was thinking of using From the specs it plays full range so I think it should do the job pretty well with a reasonable ammount of power.

Angrymike is correct, it is a common "trick" to put a slight delay on one channel (maybe even just on certain instruments) to "open up" the stereo imaging. I know people do this all the time when producing electronic music. That being said, 99% of people probably wouldn't notice the phase cancellation even without the 80 distance, boat exhaust noise, water noise, and wind in their ears.

If I had tower speakers, they would be in mono.

I don't run them though, because I am sure I annoy enough people on the lake just by having subs, and I want to limit my annoyance factor.

It's pretty comical to even list phase cancellation as a reason for running stereo vs. mono on a boat tower. It's outside, it's loud, it's not a very controlled environment. Worrying about phase cancellation and running stereo is a waste of time, energy, and money. You might as well give everyone headphones in the boat to enjoy the tunes as well.....it's pointless.

Class D is exactly what you want in a boat. The built in EQ will more than work for your application (which is pretty much full range above 60Hz or so). Many of the problems with thermal shutdown is due to individuals using AB powered amps in enclosed compartments. 10 years ago there was a big difference in class D and AB. Now there is minimal advantage to using AB in a boat. Engineers know how to design the amp and internal board layout to work best with either power supply.

Class D runs cooler tan AB = less thermal shutdown
Class D is more efficient than AB = longer battery life and higher power output
Class D is cheaper for a similar power output as well

Amps list distortion rates (which is what is being referred to when someone says an AB is cleaner than a D). If you look there is very little difference between the D and the AB of the same lines of amp. So little that only a true audiophile will be the one to hear the difference.

Usually when someone says, well an AB I had was cleaner than a D, it is b/c it was two different amps or lines. If you pull a D and an AB of the same line and sample them on the same gear, you will be hard pressed to hear a difference.

Also, keep in mind you will be bridging an AB to get the mono signal. The distortion of a bridged circuit exponentiates from normal. The distortion rate on a bridged AB output is likely to be as high or higher than the rate on D output of similar power and design.

Just my .02


(Message edited by OlskoolTige on November 06, 2007)

John and Mikeski,

I downloaded that manual because the specs on the site just didn't seem correct. The specs are a mis print. John, you will NOT want to use this amp. This amp is a sub woofer only amp.

The manual here http://www.clarion.com/us/en/MungoBlobs/567/202/DPX1800.pdf

Shows the correct specs of frequency response being 16 to 150HZ. So they mis printed it on their site. It would have been a cool find if those were correct!

If you have to do Clarion. Look at the 4 ch APX4360 in 2 ch mode will do 300x2.

Steve,

Just to clarify. You should be referring to "Full Range Class D" Which is a full range switching amplifier. There are also many different classes of these types. Although, there are not many of them on the market. This is also not one of them. This is a class D subwoofer only amp. You will see amps from Alpine and Eclipse which are full range class D using the ICE power chipset. These offer the advantages you mention in more efficiency and less thermal build up. Although the full range class D amps are not cheaper for a given power. Sub class D, yes. But not on the full range side. These amps are more expensive to design and manufacturer. Also, in saying that about more efficiency and thermal build up. This is also not just a given. Or a blanket statement. You must have the proper design and heatsink on a full range class D to gain these benefits. If you do not, you are right on par with a class ab.

I will also have to argue that there is still an audible difference in the sound quality and power output. Once again talking full range class D to full range class ab. They are getting better every year and I think you will see more and more as the years go. But right now, there are very few on the market.

Tim
Wet Sounds


(Message edited by wetsounds1 on November 06, 2007)

(Message edited by wetsounds1 on November 06, 2007)

Good point on matching the freq response too. Class D do not always reproduce higher freq, match the gear. Also keep in mind an adult over 18 hears to about 18kHz.

Tim, yes....I am not referring specifically to the amp that was asked about, and not limited range D, only making blanket statements. Thanks for pointing out the difference. This also opens up the availability of class BD amps. The usually go to around 25kHz-30kHz.

Do you think you can hear the difference 70ft back between the two (AB vs full range D or BD) though? Would you put money on it?


(Message edited by OlskoolTige on November 06, 2007)

Tim - Thanks for doing the research on the DPX amps. The web site info was misleading so that would have been a bad choice.

The APX 4360 in 2 chanel mode seems the way to go.

Now to choose subs. 2 x sealed 15's like our last boat or 2 x 12's in ported boxes? Boat gets here in 2 days so we will see what fits best.

Steve,
I'm not talking about phase cancellation from the perspective of the listener of the rider and the speaker locations. I'm talking about how when you sum things to mono, some things can cancel tremendously BEFORE its even projected through the speaker. Distorted electric guitars for example, many recordings have a 2 or more of them, panned hard left and right, and when you sum them to mono, they can get dark, drop in volume, and cancel out. Drums recorded in stereo with many microphones can change quite a bit also. Ideal mixes in my opinion, should have almost perfect mono compatibility but that is not always the case. Playback in mono is not an accurate reproduction of the recorded work, and as I said, is a consideration for me and the clients/coworkers/friends that ride with me. Not to the point where we obsess like an audiophile might, but it is a consideration nonetheless. Again, as stated, it's what we do for work, so we're more critical of that. (in the boat)
And actually, I would bet that if it was a song that collapsed poorly, people would notice the difference, even from far back.. They'd just describe it as dark, or cloudy or weird... They wouldn't recognize it as phase cancellation..
I'll take my chances on the music coming out 100% of what it should be, than guessing how it'll collapse and hope it sounds ok. (All of this is program dependent of course.)
As long as it sounds good to you, screw it and have fun.

Tim,
Thanks for the correction, fire that website programmer... I was thinking there was a new option to consider but it was false hope.

Angrymike,
I might put mine back in stereo. Grant was riding behind my boat on Sunday and commented about the cancellation. He said it was plenty loud directly behind the boat then some things disappeared when he moved outside the wake.

This is the beauty of web discussion, sharing and learning.

Mikeski,
Interesting, because I wonder if thats caused from speaker placement phasing and not mono collapsed phasing....
Probably a combo of both... I always figured it might as well come out of the speakers the best it can and take the chance on placement cancellation.
Let me know what the result is!