Subwoofer amplifier options.

[gatestick]

Am I missing something? I am wanting to find either a class D plate amp or stand alone to power the Ultimax 15 or 18 sub. (1000+ RMS watts) I will have 2-15's and 1-18. I thought I might find the amps that the sub manufacturers use such as SVS and Monoprice, or at least something similar. I have found the pro amp Crown XLI 3500 is at the top of my list. I am pretty sure that these are class A/B. Followed by Peavey IPR2 5000. The Peavey has a DSP that I don't need. I am currently using Mini DSP 2x4HD. However I believe that the Peavey is class D. I am hoping that fan noise won't be an issue. I have found many other manufactures with similar specs, but with the info that I have found their ratings are inflated or are only publishing the max output (Behringer). Another hang up for me is the budget. $1000.00 is my absolute max with tax and shipping. Many of these other manufactures are much more than my max. I would prefer class D as they don't produce as much heat, are much more efficient, and are light in comparison to class A/B.

Any recommendations to research are appreciated. Personal experience would be fantastic. Or maybe I am wanting something that doesn't exist, either for my budget or at all.

I am in the research portion of my quest as I already spent my yearly budget on a 7x200 Monolith amp for the main channels in my system. It took me about 2 years to pull the trigger on that. It is one of the best purchases I have made for my theater.

 

[Wayne A. Pflughaupt]

It looks like Peavey makes a non-DSP version of the 5000.

Might also check the Peavey’s big brother, the Crest ProLite series.

Personally, I’d recommend a Crest Pro8200 or 9200. There are some for sale on ebay right now in your price range. A beast of an amp that sells new for something like $1700. I’m using one in my bass guitar rack and it doesn't break a sweat. It’s quiet and not too heavy, only 25 lbs, which isn’t much for a non Class D amp. It’s really a handsome unit with a brushed aluminum face that looks great in a home audio rack. It’s easy enough to remove the ugly handles – remove the front plate with six hex-head screws, and the handles can then be unbolted from the back side. The only downside is that the LEDs are blazing bright – you may want to tone them down with some dark window tint.

Regards,
Wayne

 

[MediumRare]

Am I missing something? I am wanting to find either a class D plate amp or stand alone to power the Ultimax 15 or 18 sub. (1000+ RMS watts) I will have 2-15's and 1-18. I thought I might find the amps that the sub manufacturers use such as SVS and Monoprice, or at least something similar. I have found the pro amp Crown XLI 3500 is at the top of my list. I am pretty sure that these are class A/B. Followed by Peavey IPR2 5000. The Peavey has a DSP that I don't need. I am currently using Mini DSP 2x4HD. However I believe that the Peavey is class D. I am hoping that fan noise won't be an issue. I have found many other manufactures with similar specs, but with the info that I have found their ratings are inflated or are only publishing the max output (Behringer). Another hang up for me is the budget. $1000.00 is my absolute max with tax and shipping. Many of these other manufactures are much more than my max. I would prefer class D as they don't produce as much heat, are much more efficient, and are light in comparison to class A/B.

Any recommendations to research are appreciated. Personal experience would be fantastic. Or maybe I am wanting something that doesn't exist, either for my budget or at all.

I am in the research portion of my quest as I already spent my yearly budget on a 7x200 Monolith amp for the main channels in my system. It took me about 2 years to pull the trigger on that. It is one of the best purchases I have made for my theater.

Why not this? Bridgable for plenty of power and allows low pass to avoid wasting energy on the spectrum you don’t want. https://www.crutchfield.com/p_859XLS2502/Crown-XLS-2502.html

 

[BenToronto]

Since a sub driver will be making 10-20% distortion.....

On the other hand, I do notice that the power display on my sub amp takes a very enormous jump on the start of loud thumps*. So have power back-up. And I say this as somebody who usually doubts the power inflation you see at forums like this.

Can somebody tell us if Class D amps are good with headroom power?

B.
* if you've experimented with motional feedback, you know the VAST power a MFB amp is called to provide to get the cone moving initially; folks without MFB will never know what transients in the bass sound like

 

[Trdat]

Since a sub driver will be making 10-20% distortion.....

On the other hand, I do notice that the power display on my sub amp takes a very enormous jump on the start of loud thumps*. So have power back-up. And I say this as somebody who usually doubts the power inflation you see at forums like this.

Can somebody tell us if Class D amps are good with headroom power?

B.
* if you've experimented with motional feedback, you know the VAST power a MFB amp is called to provide to get the cone moving initially; folks without MFB will never know what transients in the bass sound like

Do you know of any affordable implementations of motion feedback for the DIYer?

 

[BenToronto]

MFB (maybe known as Ace Bass) mostly the realm of DIY because hard to implement commercially due to stability constraints that can be violated by manufacturing process or unsophisticated users. And I don't keep up with off the shelf availability.

At one time, Rhythmic sold kits and there are classic Infinity top of the line speakers.

 

[Trdat]

MFB (maybe known as Ace Bass) mostly the realm of DIY because hard to implement commercially due to stability constraints that can be violated by manufacturing process or unsophisticated users. And I don't keep up with off the shelf availability.

At one time, Rhythmic sold kits and there are classic Infinity top of the line speakers.

It's seems Rhytmic's kits are the best options, I was hoping for something cheaper though.

One more subjective question, I am curious how an extremely low QTC with extremely low group delay and big Bl would compare to a motion feedback sub? Is the difference than less so or is the motion feedback by far still significantly more transient?

 

[BenToronto]

Maybe somebody else can try a good reply. But here's mine.

A substantial accomplishment of HiFi has been the enlargement of feedback: except for speakers.*

B.
*I think the folks who are advocates of certain tube amps with little or no feedback are comparable to anti-vaccers in their grasp of reality.

 

[gatestick]

I think that put an end to other options. Thank you to everyone for their input. I have much to consider. I am still leaning towards crown or the crest pro lite 5.0. If there are any other suggestions please say so.

 

[gatestick]

I went with the Crown XLI3500. It seems to have all of the power needed to run the 2 - 15 inch Ultimax subs. It is everything I had wanted in an amp for this application. I was worried about fan noise as it is directly below my center channel. The fan is variable speed depending on the unit temperature. I can hear it if I mute the system after playing hard, but not when any of the speakers are playing. I was worried that the amp would roll off quickly below 20 Hz, but it actually outperforms the Dayton plate amp. I don't actually see a roll off in the graphs. I use a Mini DSP 2x4HD to do the EQ. I have it shut it down at 10Hz. One problem. I have always had a slight ground loop hum since I had an electrician install 3 - 20 amp circuits to the theater. 1 for the projector, 2 for the equipment rack. This amp picks up on that more than the Dayton did. This amp is 4 to 5 times the power of the Dayton which means the hum is 4 to 5 times louder. I have found if I unplug either the HDMI or the power cable to the Epson 5040ub projector the hum is gone. I have no idea how to fix this. I put a cheater plug on the projector, and this reduced the hum by about 1/2. I am using this as an opportunity to organize the spaghetti of wires behind the equipment rack. Any advice would be appreciated.

 

[Wayne A. Pflughaupt]

I’m going to hazard a guess that the electrician did not put all three circuits on the same phase (leg). It goes against the grain for electricians (who like to spread the demand across both phases) to do that, but it can make a difference with dedicated circuits used for audio systems.

An easy experiment, for the sake of testing try plugging all the gear into one of the outlets. If the noise goes away, then that’s the problem. Have your electrician put all three circuits on the same phase. If he complains about it, he can move another circuit to the opposite phase to make up for it.

Regards,
Wayne

 

[BenToronto]

Audio isolation transformers work really well. I was astonished at the the measurements of some automobile units from eBay for $12. Kind of a good idea even with minor hum or DC offsets.

B.

 

[gatestick]

Getting the election to come change it isn't a possibility. If I can find the information I'm sure I can change it to what is needed. I didn't have any room left in my breaker box so I had him add another box. There is only 5 circuits in that box so it should be fairly simple to correct. I am in the process of moving a plug location anyway. I also will attempt to organize the wires behind the equipment rack.

I have a panamax Isolation transformer. I don't remember the model. It has 2 analog gages on the front. 1 amps drawn and the other is volts in. It only handles 15 amps. I can't put the amplifiers on it or it trips the internal breakers. This unit has the 60Hz hum from it. I have always wondered if it should do that. It is not audible from the listening position.

 

[gatestick]

I got the power wires moved to the other side of the stud away from the speaker, signal and internet cables. I also ran a circuit to the projector location off of the back of the outlet. This will put all components on the same circuit. No phase difference issues. The 2 outlets were on different phases from each other. I do not know how to change that. I used a lab scope to confirm, but did not take a photo. The pic is of the 110 volt waveform at the outlet. The down side of the wave looks to me like it is noisy. I checked this at many other outlets in my home. All look identical. Including what comes out of my Panamax AC 5500 A/C Regenerator. This is not my scope and may just be what the display can show. It is from 1995. However, if I was to see this in an automotive computer circuit it would indicate a problem.

 

[gatestick]

No change in the noise from all of this work. Sorry, I forgot to mention that in the previous post.

 

[gatestick]

On the crown XLI3500 there is a signal and a clip light. Can anyone please explain the clip light function. Is that the signal cliping or the output of the amp cliping. When I do the setup so the light never turns on there is little output. REW never turns the light on. Only movies and some music.

I have given up on finding the buzz for now. I have ran out of inexpensive things to try. My budget is going toward the Marty sub build. Thanks for all of the input.

 

[Wayne A. Pflughaupt]

The clip light shows the input signal is too hot. If you can’t get enough signal, try moving the input sensitivity switch on the back panel to the other setting.

Regards,
Wayne