Why do people recommend a bridged 2 channel over a 1 ChMono for driving a single sub?

[Databyter 10+ year member]

I'm just wondering because I was planning on buying a class D mono amp for a 10" woofer (100-500 RMS).

I've seen comments about how it is better to buy a 2 channel and bridge it for ohm loads higher than 2 Ohm (My sub is gonna be 4 Ohm, I'm getting an enclosure).

This doesn't make a lot of sense to me since manufacturers can make their mono Amps do whatever they design them to do.

Nothing against bridging, but when I look at options I'm just looking at what I need at the end, I don't have a problem bridging if I find a good deal on something that does what I want, but why the hate for mono amps designed to do the same thing from the get go?

I don't get it, except that if I upgrade a 2 channel might be easier to sell or use for a pair of speakers.

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[misfit138 5,000+ posts]

Because most mono amps that'll do 500 watts rms @ 4 ohms are expensive. You can get a cheap *** 2 channel that'll do 500 watts @ 4 ohms...

 

[Spooney 10+ year member]

I can't think of too many if any mono amps that are designed to do their peak output at 4 ohms. So if you plan on staying at 4 ohms for a while you are pretty much gonna have to buy a bigger mono amp than you may want or need to power your sub properly while also wasting a good deal of the amps output. You can find two channel amps that do their max rms power at 4 ohm bridged all day long. If you are dead set on not wanting to bridge(although I have no idea why it matters,same result in the end) why not get a dual 4 ohm coil sub and find a mono amp that does its max rms power at 2 ohms.

 

[Ineed$ 10+ year member]

Because it's cheaper. But if you want to get a mono amp that's fine too.

 

[Databyter 10+ year member]

Good, as long is there is no technical or sq reason.

I can compare prices with the best of them.

Currently I happen to be set on a mono just because I found a good deal, actually cheaper than the 2 Channel version for the brand I want.

 

[Phatmat 10+ year member]

It doesn't matter whether you choose a mono, or a 2ch, though I would prefer to run a single sub with a mono as that's what they're designed for (such as the LPF, subsonic, etc are all there for you on a mono).

 

[misfit138 5,000+ posts]

I can compare prices with the best of them.

Then you probably should've noticed, almost immediately, that most mono amps that'll do 500 watts @ 4 ohms are relatively expensive....unless you're looking to buy a cheap pos...

 

[mclerico83 5,000+ posts]

what amp???

 

[gunz4me2 10+ year member]

Because most mono amps that'll do 500 watts rms @ 4 ohms are expensive. You can get a cheap *** 2 channel that'll do 500 watts @ 4 ohms...

I only paid $50 for this amp, used, from a friend of mine:

It is an older class bd monoblock that will produce 500 watts RMS @ 4 ohms or 1,000 watts RMS @ 2 ohms. I was hoping it would be a perfect match for a pair of DD1508s that are SVC 4 ohms.

 

[misfit138 5,000+ posts]

I only paid $50 for this amp, used, from a friend of mine:

It is an older class bd monoblock that will produce 500 watts RMS @ 4 ohms or 1,000 watts RMS @ 2 ohms. I was hoping it would be a perfect match for a pair of DD1508s that are SVC 4 ohms.

nice find.

 

[gunz4me2 10+ year member]

nice find.

It was one of those right place, right time things. Dude lost a couple of set screws and no one wanted to buy the amp. He said "Give me $50 and it is yours" and I was like "OK..."

 

[Team Maxxsonics 10+ year member]

Needing 500 watts at 4-Ohms, I would prefer an A/B-Class 2 channel amp bridged over a D-Class mono.

Most D-Class amps are rated power (so they claim at least) at .1% to 2% THD while A/B-Class amps are typically rated at .01% to .005% THD and some can be found with Subsonic and Low pass Filters.

Damping factor is usually much higher on A/B as well.

You got a good price for the RF mono but this is not typical.

 

[gunz4me2 10+ year member]

Needing 500 watts at 4-Ohms, I would prefer an A/B-Class 2 channel amp bridged over a D-Class mono.Most D-Class amps are rated power (so they claim at least) at .1% to 2% THD while A/B-Class amps are typically rated at .01% to .005% THD and some can be found with Subsonic and Low pass Filters.

Damping factor is usually much higher on A/B as well.

You got a good price for the RF mono but this is not typical.

I've actually been lucky with some of my used gear purchases.//content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

You are correct though... Purchasing 500 watts RMS brand new for 4 ohm power is usually more cost efficient with a stereo class ab amplifier bridged.

 

[Databyter 10+ year member]

Needing 500 watts at 4-Ohms, I would prefer an A/B-Class 2 channel amp bridged over a D-Class mono.Most D-Class amps are rated power (so they claim at least) at .1% to 2% THD while A/B-Class amps are typically rated at .01% to .005% THD and some can be found with Subsonic and Low pass Filters.

Damping factor is usually much higher on A/B as well.

You got a good price for the RF mono but this is not typical.

Interesting. I am going for SQ above all, and for my four channel I paid a bit more and went with an A/B with good specs.

For the D Class Mono sub Amp. I thought the switching noise was all in the higher range, so that with a low pass filter and driving a sub it would still be a SQ solution (since the noise produced is out of the range of the Sub).

Regarding THD My JL Audio 4 channel, which I thought was a SQ amp but it only has 1%, which I thought was decent (it's a discontinued G series so I don't know how it stacked in the lineup from economy to premium, I should have asked here before I bought it I guess).

The D Class Mono Amp I'm looking at also has 1% as you stated.

I was told years ago that anything less than 1 % is unoticable anyway, but I don't know.

They also told me that anything above 192 KBPS MP3 is CD quality and indistinguishable from 320 KBPS (that I encode at) and I have proven to myself beyond doubt that this is NOT true, I can easily hear the difference in dynamic range and depth of Bass and High end.

At any rate the 4 channel is bought and shipped, the Sub amp is still up in the air, since I have picked one out but wont be able to afford buying it for about a month. So I'm open to learning more and thanks to all who answered my thread.

 

[gunz4me2 10+ year member]

For the D Class Mono sub Amp. I thought the switching noise was all in the higher range, so that with a low pass filter and driving a sub it would still be a SQ solution (since the noise produced is out of the range of the Sub).

There are several modern day full range class d amplifiers that are nearly indistinguishible from their class AB counterparts. The JL Audio HD series is about the best I've ever heard in a 12 volt full range class d amplifier. I was told the new Zed amplifiers are extremely close to sounding like a class ab amplifier.

Other diamonds in the rough would include those Kenwood XR amplifers and the JVC Arsenal amplifiers for some decent sounding full range class d wonders.

Until I hear the new PDX amplifiers, I am ranking Alpine dead last in the full range class d wars... I could never put my finger on why the older PDX amplifiers didn't sound right, but something was always amiss with them Whether it was the excessive noise floor or the lack of midbass punch, something just didn't sound right about their full range class d amplifiers...

Lastly, many fail to realize that full range class d reproduction has been around in the pro audio world since 1998 or so. Glad to see that car audio is finally starting to catch up 12 years later. It's not like we could have used smaller, more efficient amplifiers sooner for car audio applications.

The D Class Mono Amp I'm looking at also has 1% as you stated.
I was told years ago that anything less than 1 % is unoticable anyway, but I don't know.

On subwoofers, audible distortion is hard to detect until it starts to reach the double digit stage. On mids and highs, some start to notice it between 3 and 5%

I blame the CEA 2006 Standard for everyone using 1% distortion ratings these days.//content.invisioncic.com/y282845/emoticons/pissed.gif.9f665f96bc89e98e708dabd4580bb591.gif

They also told me that anything above 192 KBPS MP3 is CD quality and indistinguishable from 320 KBPS (that I encode at) and I have proven to myself beyond doubt that this is NOT true, I can easily hear the difference in dynamic range and depth of Bass and High end.

That all depends on the source material and encoder utilized. Not all MP3 encoders are created equally, and the Advanced Audio Codec (AAC) is WAY better than MP3 for cd like quality at 400 Kbps. If you want to have fun, experiment with ripping songs from the CD, using Lame to encode to the various MP3s, then run Foobar 2000 with the a/b/x tester. I've been able to pick out differences depending on the encoder utilized and the source material.