Amp design considerations

[BumpedCX5]

So I'm getting ready to buy an amp to run my X15v3 (dual 1) and was originally looking at Sundown full bridge amps. Seems like a bargain for the amount of wattage they put out. Thought I was going to settle on a SIA3500D but now considering a Salt 4 instead. Both will put out enough power at 2 Ohms to run the sub well. This is all going to be in a daily driven vehicle and for the most part driven to normal listening volumes with occasional beating. I don't see any upgrades in the near future happening to take advantage of lower impedance power. My thinking is that at 2ohms both amps should have it relatively "easy" and be more efficient/reliable. The Salt cost almost 1k more than the SIA here. Any reason to spend the extra $$$ on the Salt over the SIA? Better yet if this isn't allowed because it's considered an amp comparison I'll ask it this way. Is there any reason to go half bridge over a full bridge amp for a system like this? All wiring is 0 gauge (or 0/2 welding wire) and current 100A alt will be getting replaced with a 240A. Won't have lithium just a Northstar NSB-AGM34/78 battery. Thoughts?

[Dafaseles]

My opinion, if you run either amp, run 2 of those batteries. 

As far as either or, my personal opinion is half bridge, Korean board. 

As far as full bridge amplifiers go, if I had to choose, the Sundown SIA amps would be my very first choice by far. Sundown will stand by their products and their customer service is top notch. All amps they make are far from junk as well. 

Some say (though not necessarily proven) that the half bridge amps handle the low notes better, and that kind of makes sense because the damping factor of the SALT amps are above 400. I can't even find the damping factor of the SIA's, but I would put money on it that it's less than 200.

Also, the SIA line is meant to be a top shelf budget amplifier, while the SALT like is meant to be top shelf, powerful amplifiers that aren't budget amps. 

Sundown Unofficial on YouTube has even lightweight compared the two. Basically, to keep the SIA's and SFB's as budget as possible, they did cut some corners and use less than to tier components. The SALT line, the best they could get. 

Is the SALT 4 worth $1000 more than the SIA 3500? In my opinion, yes. Would you be unhappy and disappointed with an SIA 3500? I don't think you would. 

[BumpedCX5]

Thanks for the insight. I haven't seriously played in car audio for years so the half bridge topology is a new one to me. When I was building systems paying upwards of $2k for a 1000W class D was normal lol. Seeing prices a quarter of that now for 5x the wattage is unbelievable to me. I've no doubt the extra $1k for the salt is justified as far as quality and build are concerned my debate is whether I'll even reap the benefits of the better amp on such a "simple" setup. I just want reliability out of the system and, obviously, a good performance. I considered the two battery route but opted to shoehorn the largest battery I could in order to save a bit more space. Realistically the X15 is way overkill for 99% of my listening and I'll probably never use it to it's full limits. Even when I had systems with 1000's of watts in the past they weren't beat on very hard. I prefer overkill with headroom I guess. Should voltage become a problem I'll see about a second battery but space is already tight with what I have planned and the vehicle, being a daily driver, needs all its seats and on trips the ability to carry a spare lol.

[Dafaseles]

Well, if space is an issue, that's another spot where the SIA wins over the SALT. I actually own 2 SALT 4's. They are big and heavy! 

I've read that full bridge amplifiers don't work well with a lot of voltage changes. Though, if you don't slap full blast all the time, and for the most part, keep it moderate, that might not be a huge issue. 

I know the crossovers on the SALT amps are vastly superior over the SIA's, so the actual sound quality could be an issue. 

What it comes down to is, I'm probably getting too technical, trying to give you all the information so you can make the best decision for you. Both amps are quality. Both amps are backed by amazing customer service and an established company that isn't going anywhere, anytime soon. Maybe the only real deciding factor here is you'd be happier with an extra G in your pocket, and being able to tuck that little amp in the corner and forget it's even there. And hey, if you really just don't like the sound quality from the SIA (though I doubt that will be an issue) spend $600 on a DSP, and your still up $400 from buying the SALT. Just food for thought. 

[BumpedCX5]

No worries on getting too technical. Honestly I think it's the lack of specs that makes my choices harder sometimes lol. I think I'm going to try the SIA and see how it goes. I'm thinking part of my hesitation is how inexpensive amps are for what they put out now. I've seen the amp dynos of countless amps now and know they put out the power. It's a way of thinking from years ago where you just didn't have options like you do today. Buy cheap by twice and there was no amplifiers making anywhere near 1000WRMS under $1500. I remember when the JBL BP1200.1 came out and it was right around $1k. They couldn't keep them on the shelf in my area because they were so "cheap". Even at $1700 the Salt 4 is a bargain compared to 20 years ago when dealer cost at the shop I worked at for my 1500W amp was about the same. I just need to get out of my old mentality and embrace the new age 😅. Thanks for the info Dafaseles.

[Joe X]

If you want a well made full bridge amp just strap two half bridge 1000W amps to get 2000W @ 2 ohm, that should be less than $1K in cost.

[CorNut]

I'm far from as knowledgeable as the others posting, however, if I were on a budget I'd choose something like the half ohm stable Taramps Smart 3. The reason is, running at .5 ohm the amp will output its full rating, which it'll also do up to 2ohm. It'll in a sense, help prevent box/impedance rise. Maybe that isn't a huge deal/worth worrying about but it's something I read about that others were saying is a good thing.

[BumpedCX5]

Joe X getting the power for under $1k isn't a problem there's a fair few amps that would easily hit my power requirements at 2 ohms. Going with half or full bridge is more a consideration because half bridge didn't become mainstream until I was long out of the game and I'm just not familiar with them as far as quality/reliability goes. I'm leaning to the SIA right now and if it doesn't do what I want I'll probably look at full bridge options like the Salt series.

 

CorNut I had looked at the Taramps as well. Running at .5 will be a little less efficient and basically run the amps components as hot as they can because it'll be pushing them to their current limits. Box rise would be a consideration if I was planning on going all out for numbers but for a daily driver that will rarely make it to half volume it shouldn't be a major factor. The SIA amps come with a remote bass knob and the Taramps don't so to run one on the Taramps I'd need to add a knob to the signal chain. Since this system is going to be built using the stock Bose system I'm trying to stay away from adding anything to the signal chain that I don't have to. Thanks for the suggestion though. 

[CorNut]

Actually, the lower impedance somehow runs more efficient, power draw wise anyway. They go into detail a bit about it in this dyno video. I'm sure the SIA has better QC if you're not worried about extracting every last watt.

 

 

 

 

 

[Dafaseles]

11 hours ago, BumpedCX5 said:

No worries on getting too technical. Honestly I think it's the lack of specs that makes my choices harder sometimes lol. I think I'm going to try the SIA and see how it goes. I'm thinking part of my hesitation is how inexpensive amps are for what they put out now. I've seen the amp dynos of countless amps now and know they put out the power. It's a way of thinking from years ago where you just didn't have options like you do today. Buy cheap by twice and there was no amplifiers making anywhere near 1000WRMS under $1500. I remember when the JBL BP1200.1 came out and it was right around $1k. They couldn't keep them on the shelf in my area because they were so "cheap". Even at $1700 the Salt 4 is a bargain compared to 20 years ago when dealer cost at the shop I worked at for my 1500W amp was about the same. I just need to get out of my old mentality and embrace the new age 😅. Thanks for the info Dafaseles.

I remember those days. My JL 1000/1 v1 was $1,200. Or something like that. I remember if it wasn't a dollar a watt, and heavy as hell, it was probably garbage. 

Nowadays, the Korean half-bridge boards are what everyone goes to for huge power. The SALT amps, DC amps, Cresendo, and many more. 

As far as the full bridge amps, the only one right now I would even think about using are the SIA's and maybe the Taramps Smart series. Other than that, I'm not 100% convinced of their quality yet. Though I have spoken to plenty of people who love the SFB's and others like it.