The Two Channel Advice Thread

EDIT: Purchased a Crown XLi3500


I believe my 2-chan subwoofer amplifier is on it's last legs - and it's about time I upgraded anyways. It is a Samson SX1200. It's doing 450x2 @ohm stereo. It's a bit weak for the large area the subs occupy. It is also a bit noisy (fans).

Recommendations for a stereo subwoofer amplifier, woofers are DVC 2ohm, and I like to keep them at 4ohm - seems like a fair load for this type of driver. They are 1,000 wrms each. CSS SDX12 built to sealed spec. So for HT material, they really need some help - 450 might not cut the mustard fully, but I do get to reference level at seating position - I think the amp hard clips at reference + 0.5 db +

I don't need anything fancy - I use dirac live for tuning, it is capable of handling stereo subs.

When I was younger, I would take an inverter and crank the voltage to 14.4 and see how much I could get out the wall and into a 12v car stereo amplifier. I had a pair of 15's and bass shakers under my bed. I was perv when letting girls on my bed and giving them a show, but also slightly embarrassed for spending my time in that way - it's kind of a weird hobby for a kid. Pimp my bedroom.

I do wish I had built dual vented 15's for my current setup, but the space IS limited and the CSS's are right in my wheelhouse. My car audio handle is "ImageDynamicsM3" I think. I was on a bunch of car audio forums - it was cheap and accessible. Hi-Fi was snooty. Personal audio just made the most sense. No bull-shit, no competition's. Just you and your music in the way you like. I've been able to try spices, herbs, delicacy's, all sort of other libations through the use of headphones. Yes that is a metaphor for different headphones that are much easier to try than speakers. In most ways, they are better for me. Lack of pure immersion from a stereo setup unless you are in the sweet spot with a properly acoustically modified room, not a normal-ass house.

Anyways... 2-channel amp recommendations...

 

What are people's thoughts on mitigating vibration in electronics?

I am considering some Class D monoblocks because I find the technology to be very interesting. I wanted to put them directly behind each speaker on the floor. I would have a 2 - 2.5M balanced interconnect from the preamp to each power amp, then a < 12" speaker cable going directly to the loudspeaker. The binding posts for each speaker are basically on the floor.

The desire to put the amps close to the speakers and on the floor is to keep as much empty space between the speakers as possible. I've found that this is necessary for good mid-bass and sub bass performance. If I can get all source gear spread out and close to the ground, I think this will have a nice sonic benefit. Putting the source gear off to the side will probably not be an option.

However, I wonder what could be the effect of vibration on the amps? Some of these Class D amps are only 5 - 10 lbs. My speakers have side-firing woofers and side-ports. I wonder if low frequencies would affect the amps being close to the speakers? I have seen the effects of vibration on electric circuits and devices during automotive validation testing, but never sub-bass from loudspeakers. Is there anything to be worried about? Might it be necessary to add mass to the chassis and decouple them from the floor?

 

Short answer would be do it. Longer answer is that capacitors in general are sensitive to vibration and for audio where we can sometimes hear immeasurable differences, it can matter.

Having said that, you probably really want to ask yourself why consider class D...

 

Why consider Class D? I find the latest tech to be quite interesting. My ultra fancy A/B power amp sounds wonderful. But it idles at 285-300W from the wall while I listen at < 77dB. Most of the time I am listening at 65-70dB. The efficiency of Class D is intriguing and the audible silence is also nice. I've tried a Hypex NC252mp and it was very interesting. I want to try some others.

Similarly, I got two Schiit Gjallahorns yesterday. With the right preamp they are DEAD SILENT. They idle at 10W each from the wall, and pull 11-12W at 77dB peak volume in my system. Cool. But there is a lot to be desired in terms of all of the audiophool sound quality that I am after. The detail, soundstage layering, separation, and tonality are simply not there. For now I will keep using them because the prospect of turning 10W into sound vs. 300W into the same level of sound is useful to me today. For future iterations I want to plan for something different.

 

Well let me know if you find one that sounds good enough to replace what you got. I'd say class D with Hypex has gotten to the point where it's acceptable, especially for TV use, but I still wouldn't critically listen to one. If you find a great one, I would love to use it for my TV setup...

 

Using them as monoblocks for 30W each or...?

 

Yes, using them as mono blocks for Vivid Kaya 90. Audia Flight FLS-1, Topping A90D, and Holo Bliss as preamp. Audia Flight sounds the best but it is inherently noisey which is really bothering me. The A90D and Bliss are dead silent even with my ear on the tweeter. I'm only about 7 feet from each speaker in my current space so getting everything balanced has been really hard. I expect to be in a much better physical space in about 4 months so I am scoping out various things for when I have a new setup with more space and an ultra-short-throw projector. So, opening up the space between the speakers is important to fit the UST PJ properly as well as better mid-bass and bass response.

 

mm, not so sure about adding mass. You can just weigh an amp and choose the proper size and type of Sorbothane hemisphere for it. Link to a site where you can pick them up: https://www.isolateit.com/products/...eet-with-adhesive?_pos=3&_sid=6a140290d&_ss=r)

 

If you regularly listen <77dB, I wouldn't be concerned at all about vibrations affecting your amps. Your caps will age out before the vibrations do anything to them.

 

Amps like dacs, computers and everything else in your system will vibrate and will have a small effect. I would not add mass but rather would try different footers to decouple from the floor. Experiment and see what you hear. Sometimes a sandwich approach can work well and you don't even have to buy stuff, try wood, foam, etc.

Generally I have found that suspended wood floors are the worst, concrete slabs the best as far as their contribution to overall "tone" without intervention. Enjoy!