Auto class D

tratliff

Hey polkies. I have lots of experience in class A/B in what I might consider the good ol days. Had a car in the late 80’s early 90’s that I competed with. I’m looking to build a newer system in a car that we are considering class D JL equipment in. A VXi 1000/5 and 800/8. This is new to me but does allow for total active cross overs/time alignment/phase control. I like the idea but would like to hear from users that have used it. Did you see value of the advancement? Am I missing something??

treitz3

Class D for the lowest of the spectrum of frequencies (especially given today's technology with Direct servo....and even without) is fine. You move up into and beyond the lower midbass frequencies and I may need to take you down by the river for a talk. Catch my drift?

Tom

tratliff

Understood Tom. You speaking from home or car audio experience?
You might reconsider based on speaker selection. But that’s another discussion.

treitz3

A mixture of both. What I have for the rig at home and what I have designed and listened to for car (or in my case, truck) audio, using Focal's TOTL speakers.

Tom

tratliff

Good information. Thanks sir. What Focals you talking about?

treitz3

https://www.focal-america.com/product/es165kx3/

The system I designed would be about 7K for the minimum but would be CONSIDERABLY more if I went with Direct Servo, added tubes into the mix and lost the class D.

Tom

tratliff

Very interesting. Utopia M is exactly what I am considering. But all backed by active cross over and time alignment.

treitz3

Yeah, that was my original plan....and one I may stick too.

I was gonna go with this one - https://www.jlaudio.com/products/vx1000-5i-car-audio-vxi-amplifiers-98632

With a headshell - https://www.kenwood.com/usa/car/excelon/ddx9907xr/

Fully customizable. Lots of configurations, channels and the like but when I heard it? Eh....

Nowhere NEAR where I wanted to be. I guess the home system has spoiled me. Yeah, it sounded great and had that chest pounding thump but other than that? It sounded like class D. Subpar to what I am used too. This, in a vehicle that was fully protected in the doors and trunk with a plethora of Dynomat and just about everything else you could imagine in it and I was left with the impression of...

Okay, that was cool but what else is available? This sounds like....(I'll be kind here) decent crap.

I loved the speakers, mind you. They were good, detailed and very nice. This system was dialed in using just about every tool they had at their disposal, adjusting everything from slope, curve, drop off, frequencies and I believe it had an external 1K amp?...hell, that was a few months ago. Basically, there were so many things that you could adjust? One would get lost in just the adjustments....but they were there if needed. In SPADES.

TBT, I wasn't impressed....which is why I am still auditioning and designing.

Now, did it sound great for a car system? Oh, hell yeah! Without a doubt and twice on Tuesdays. Was it what I wanted and have been accustomed to? Hell no....so I keep at it.

Knaw'mean broskizzle?

Tom

tratliff

Yeah. That is my same concern. Has my home system changed my view point. As good as the 1000/5 and 800/8 are, will they meet expectations. The system has been well thought out. Would be installed and fab’d by very experienced professionals. In fact some of the individuals in the planning process are the same that helped me design my system in the 90’s where I was invited to the nationals two years in a row. Cost is not a real concern. But is when you consider the final product and sound quality.

Jstas

The class D amplifiers of today are not the same as the class D from decades ago.

Class D usually provides big power in a small footprint because they are insanely efficient. The biggest drawback was in 1996, when they were introduced, the computing power needed to sustain a switching speed high enough to handle full-range amplification in a class D design was very expensive and bulky. It would have tripled the cost of an amplifier.

But nowadays, the phone in your pocket has enough computing power to handle it no problem. Hence the reason why your 1-2 watt amplifier in your phone is a class D design.

All of these small amps with big power that you can stick anywhere because they never get hot are possible because of the class D circuits and availability of very small processors with very high computing capabilities.

Class D could always handle full-range, the supporting tech was not up to snuff. Now it is and that's why you are seeing these tiny bricks for amplifiers that are putting out hundreds if not thousands of watts on super clean power with more than enough headroom for the dynamic range of full-range audio reproduction.

But, hey, y'all go with what you want to think.

I have no experience with JL Audio. I avoid them because I've always found them over-hyped and subsequently over-priced.

I did, however, just jam a Soundstream Picasso Nano PN5-640D into Jackie's car and wired the entire thing in with the high level inputs so she could keep her Sync system. It's an impressive amp with a boatload of power. Clean and clear and when the weather breaks and I can get Fiberglas resin to cure, I'll have her subwoofer in too.

The best part is, everything was so small that you can't tell there's anything done to her car...until you turn the volume up.

I'd grab a full-range class D amp again for sure. I wasn't expecting much but I know I was demanding a lot and it exceeded my expectations and demands by a long shot.

tratliff

Jstas wrote: »

But, hey, y'all go with what you want to think.

@Jstas Thanks for the information. Great feedback as it echo's what others in the industry have been saying. I just don't have any experience with them as its been many years since I put a system together. Just looking for opinions and advice at this point.

tratliff

treitz3 wrote: »

I was gonna go with this one - https://www.jlaudio.com/products/vx1000-5i-car-audio-vxi-amplifiers-98632

With a headshell - https://www.kenwood.com/usa/car/excelon/ddx9907xr/

Hey Tom. That is one of the amps that is in the plans for me. But I would use it in a 3-channel configuration and also add a Vxi 800/8. That adds 8 additional channels of power which would give me 100x8, 200x2 and 600x1. This would allow for 100% active cross-overs and time alignment/phase control to each individual speaker. The Focal Utopia M series requires active cross-overs. At first I was considering just going with a 5 channel setup but, if I build something like this I would want full control.

Speakers would consist of:
Focal Utopia M Tweeters - 2 pair
Focal Utopia M 3.5" - 2 pair
Focal Utopia M 8" - 1 pair
JL 10 TW3 - 1 in a sealed enclosure

Jstas

Where'd my post go?

I wrote a big long thing about Class D amps and why they work better now than they did 20 years ago and it's not here.

BlueFox

Jstas wrote: »

Where'd my post go?

I wrote a big long thing about Class D amps and why they work better now than they did 20 years ago and it's not here.

This post?

Jstas

BlueFox wrote: »

Jstas wrote: »

Where'd my post go?

I wrote a big long thing about Class D amps and why they work better now than they did 20 years ago and it's not here.

This post?

No, foolish.

If I meant that post I wouldn't have said anything.

tratliff

Jstas wrote: »

Where'd my post go?

I wrote a big long thing about Class D amps and why they work better now than they did 20 years ago and it's not here.

@Jstas That sucks that it was lost. I would like to get the details of what you had written.

Jstas

It was a lot, I don't know if I have time to get back to it today. Maybe tomorrow.

I'll write it back out in a text file and cut and paste it so it doesn't get eaten again.

I don't know what happened. It said it posted successfully and showed it on the page with me as the last poster. It would have been posted about 11:50 AM and when I came back in the afternoon because the post was highlighted with new responses, it was gone.

Then again, lunch time yesterday is when all these stupid problems started.

WLDock

tratliff wrote: »

treitz3 wrote: »

I was gonna go with this one - https://www.jlaudio.com/products/vx1000-5i-car-audio-vxi-amplifiers-98632

With a headshell - https://www.kenwood.com/usa/car/excelon/ddx9907xr/

Hey Tom. That is one of the amps that is in the plans for me. But I would use it in a 3-channel configuration and also add a Vxi 800/8. That adds 8 additional channels of power which would give me 100x8, 200x2 and 600x1. This would allow for 100% active cross-overs and time alignment/phase control to each individual speaker. The Focal Utopia M series requires active cross-overs. At first I was considering just going with a 5 channel setup but, if I build something like this I would want full control.

Speakers would consist of:
Focal Utopia M Tweeters - 2 pair
Focal Utopia M 3.5" - 2 pair
Focal Utopia M 8" - 1 pair
JL 10 TW3 - 1 in a sealed enclosure

Nice plans there! This takes me back to the late 90's. I had an active 4-way system that consisted of a Pioneer DEX-P1R DPS head unit that had just come out. It connected to a couple of Audio Control EQX units, then split to MTX Thunder 5400X 5 ch. and 4300X 4 ch. amps. This gave me nine active channels of stout class AB power!

The speakers were Focal Expert tweeters, midrange, and midbass raw drivers and a single 12" Alumapro subwoofer. I had plans to build a show system in my '86 BMW 318Ti Sport and compete in SQ events. However, I never got it to that level.

That was a long time ago but nothing has changed. The best sounding systems are those that have power reserve and don't run out of steam when the music starts sounding good. Class-D can work wonders for the 100x8, 200x2 and 600x1 system that you have planned.

Back in the day I used to install systems for others and I've had a great experience with the JL Audio SLASH class AB 5 channel. I put one in my buddies Ford Explored spare tire well. It was in there for about 3 years and provided clean noise free effortless power without fail. For sure worth the price he paid!

Don't think for a minute that these newer JL Audio Class D amps are a step back from class AB in an automotive setting. 11 channels / 1800 watts JL Audio power will make you forget your listening to class D when driving around town. Maybe a different can be heard in a quiet parked setting... Like SQ competition judging? The AB amps I would not mind trying are the Stereo Integrity new amps.
https://stereointegrity.com/product/siq/

Jstas

The Soundstream Class D I just put in Jackie's car has no discernible difference between it and any of the Class AB amps I have hanging around. And some of them were heavy hitters in SQ in their day. It's every bit as good as the old PPI and Profile amps I have as well as the more modern Hifonics amps. The cleanest amp I've ever owned is my Kenwood eXcelon KAC-X650D which I paid out my nose for in 2002 and it's as clean as that.

If the JL Audio amps are even close to that or better then you won't know a difference in the least.

Also, the old PPIs are Class A and you can fry an egg on them when they're rockin'.

tratliff

Thanks for all the feedback. I wanted to make one correction to the specs I listed yesterday. I mentioned the Vxi 800/8 providing 100x8 but that is only if run at 2 ohm. I will be running it at 4 ohms and it will provide 75x8. Not that it matters much but just noticed that as I was reading.