Rockford R750-1D (750W) vs Sundown SALT-2 (2000W) barely any difference in volume? No voltage drop when clipping?

[Terrum 10+ year member]

That is ONLY if you want to put 2kW into that one sub.

Initially I was concerned that the amp wasn't outputting 2kW or anywhere near it, because when slightly clipping I was not getting a voltage drop and no mechanical noise and/or burning smells. But now after I have experimented with the subsonic and LPF more I started getting voltage drops when slightly clipping and smells of burning coils, so in my eyes that pretty much confirms that at least 1kW is being pushed into it now.

TBH, I do not know if you can acheive over 1200 watts on that 90 Amp alternator.

Very unlikely. As mentioned in my first post the alternator is lacking, hence I made the decision to splash out on the SALT amp (because of its 'low voltage technology') hoping I could output 1850W @ 12V on the battery (when I have the car turned off) as that wattage is supposedly what it can handle.

Anyway I'll check the speaker terminals in the morning and write back with any updates. Thank you so much for your input and help, it's been a real pleasure learning on this forum as always

 

[winkychevelle 10+ year member]

Apologies for my ignorance, but what exactly is it I need to do? The formula is accurate (44.72VAC = √2000W x 1Ω) so when measuring the speaker terminal's voltage I'll be looking for ~45V, but do I need to do this when playing a tone just before the clipping point?

I've had a little play around today with the subsonic and LPF and got it to start outputting better, it actually drops voltage when clipping now and the coils start smelling (so I know for sure I'm getting the best output now) so that solves most of this thread.

But I am still curious as to why the kicks are louder than the basslines (e.g: in trap/rap music you have a kick then a long bassline after it). Currently it clips on the kicks so now I'm getting very loud kicks but quieter basslines with the same songs I've used for testing for years on many amps that haven't had any trouble equalizing the kicks and basslines.

Check you eq you may be boosting the upper bass region causing an early clip. Kicks usually clip early in my truck as well. A small blink of a clip light isn't a big deal you just don't want it on for very long

 

[Terrum 10+ year member]

Check you eq you may be boosting the upper bass region causing an early clip. Kicks usually clip early in my truck as well. A small blink of a clip light isn't a big deal you just don't want it on for very long

EQ is flat on the headunit and bass boost is as low as I can get it on the amp (0dB).

It could be very likely though that on other amps I was clipping the kicks so much that they would balance out with the basslines - obviously not ideal but I have a feeling that's what was happening. In that case, as you said, a small blink of clipping isn't a big deal so maybe I can toy with that.

Thanks so much for the useful response

 

[Bobbytwonames 5,000+ posts]

No worries. With a 40Hz. tone and radio volume at 75% (in your case 100% since you know the signal is clean) ,you will look to acheive 45vac. That is ONLY if you want to put 2kW into that one sub. For lower wattage input the square root you want to use on the sub. TBH, I do not know if you can acheive over 1200 watts on that 90 Amp alternator.

I was running a Sundown SIA3500 @ 2 ohms (3,000 watts) on two HD 8's with a 55 amp alternator, one AGM, and one bank of Lishen lithium (18ah). It can be done. 142.9 @ 33 hz.

 

[1aespinoza 10+ year member]

I was running a Sundown SIA3500 @ 2 ohms (3,000 watts) on two HD 8's with a 55 amp alternator, one AGM, and one bank of Lishen lithium (18ah). It can be done. 142.9 @ 33 hz.

Bench testing class A/B surfboards taught me that one lead acid battery is sufficient for un-neighborly bass. Logical online discussions have swayed me that alternators are the ones providing all the boom juice. So I am stuck in the middle.

 

[Bobbytwonames 5,000+ posts]

Bench testing class A/B surfboards taught me that one lead acid battery is sufficient for un-neighborly bass. Logical online discussions have swayed me that alternators are the ones providing all the boom juice. So I am stuck in the middle.

Alternators, lithium batteries, and agm batteries. You don't need as much as the first picture. Maybe the second picture.

 

[2023 LTZ]

Has anyone asked the question of this amp, not the rf, being over rated?
Maybe it’s true output is 700 dirty watts hence why the subs don’t sound different.
I switched from 1200w 1ohm on my rfp3d4s to 1200w at 4ohm and the difference was quite noticeable. Certainly not on db but quantity and quality of the fullness of the bass.
I switched amps from rf p1000.1 to t1500.1
The p at 1ohm out out 1417 but only 1200 was useable by my two 600w subs. The t put out1500w at 4ohm still same subs using 1200. Gain was not set using the 3.14 formula as I found that in excess of what speakers could handle w out clipping.
More useable bass.
This is of course
IMHO

 

[winkychevelle 10+ year member]

Has anyone asked the question of this amp, not the rf, being over rated?
Maybe it’s true output is 700 dirty watts hence why the subs don’t sound different.
I switched from 1200w 1ohm on my rfp3d4s to 1200w at 4ohm and the difference was quite noticeable. Certainly not on db but quantity and quality of the fullness of the bass.
I switched amps from rf p1000.1 to t1500.1
The p at 1ohm out out 1417 but only 1200 was useable by my two 600w subs. The t put out1500w at 4ohm still same subs using 1200. Gain was not set using the 3.14 formula as I found that in excess of what speakers could handle w out clipping.
More useable bass.
This is of course
IMHO

The dampening factor is higher at 4ohm

And if you wired each sub up to 8ohm then down to 4ohm you effectively doubled the motor force buy doubling the amount of coil in that gap at any given time.

This things would sound cleaner. You are still drawing the same amount of current from the alt assuming 100% efficiency. But an amp that is rated at 4000w at 1 ohm will naturally be more efficient at 1000w 4ohm, even once you drop the 4000w at 1ohm to 1000w at 1ohm. This is simply because the stress on the internal components is less.

 

[Terrum 10+ year member]

No worries. With a 40Hz. tone and radio volume at 75% (in your case 100% since you know the signal is clean) ,you will look to acheive 45vac. That is ONLY if you want to put 2kW into that one sub. For lower wattage input the square root you want to use on the sub. TBH, I do not know if you can acheive over 1200 watts on that 90 Amp alternator.

Just thought I'd quickly update this thread as it's been a long while since I promised an update, I finally checked the AC output of the speaker terminals, I get 42VAC before clipping, and around 55VAC when turning the volume up just one notch to where it clips. So now that I know the amp is performing as it should be, I finally got myself 2x SA-12 V.2s and I'm working on a box today so I'll update my design thread as soon as I can: https://www.caraudio.com/threads/a-newbies-first-design.611379/

Many thanks again everyone for all your input and help, it's been an incredible experience as always