New Home Sub needed

[Grinder]

In the off chance you're unaware, this series of Crown XLS amps have selectable input sensitivity of 0.775V or 1.4V (the former, for use with AVR and the like).

[Jdunk54nl]

Ya, it is set to the .775v option. At normal listening level it MAYBE flickered the first signal light. Now that light is on and it can get up to the next two lights.

Every checked out fine via scope and dmm too.

Also found out the internal amp goes up to 36v without clipping (no load on it)

[Grinder]

Come to think of it, I was initially less than completely satisfied with the output of my first XLS (the 1002). However, given the task of driving four budget 8" subs in sealed 0.5 ft^3/ea. to somehow keep up with 94.5 dB (1W/1M) midbass (and bullet tweeters - of course, I had almost no clue what I was doing when I selected this incompatible combination of drivers), it should have been no surprise that there would be great output disparity. The addition of a miniDSP 2x4 allowed me to substantially raise the subwoofer signal level while PEQing the low end as well, while substantially attenuating the signal to the receiver (midbass and treble).

It was a very similar situation when I added the pair of 15" Dayton RF subs to my main system. While the sensitivity of those two subs is far greater than that of the four 8s in the other system, the XLS 1502 is tasked with driving them to somehow keep up with a pair of 3-way horns of characteristically high sensitivity. Enter the Dayton DSP-408 (to raise the sub signal while attenuating the horns signal).

[Jdunk54nl]

Ya, I think if I was pure external amps coming from the AVR, I wouldn't have any issues. The combination of using the avr internal amps makes it interesting if you do not want to buy a cleanbox pro or some other type of line driver. I had to ultimately set the loudest speaker at -10db in the avr level and the sub out at +10db. This still only allows for me to be listening at the -20db to -15db volume levels. I might get some movies to -10db but that is to the point where you can't talk anymore during the movie because you can't hear the other person.

I wonder if a minidsp would help too. I know my avr says 1.0v preouts but when I measured playing tones I was able to get well beyond that. I think I got it up to +6v before it clipped, this was at volume level +8db though on the avr. The internal amp clipped at +4.5db.

But ultimately, I am happy now. My sub definitely has more power than it did. The crown can be ran near maximum if I want. Nothing is clipping anywhere at my volume levels and I can get to painful levels.

Now just to eventually get some hypex ncore amps for my speakers and build a ultimax 18 kit from parts-express...

[Grinder]

FWIW, I've found that the Dayton DSP-408 has a considerably lower noise floor than that of the miniDSP 2x4, though I'm not at all sure how they might audibly compare with respect to subwoofer signal alone.

[Jdunk54nl]

That is good to know....maybe I upgrade my dsp.2...then put that in my wifes car....then pull her dayton out and use it in the home stereo...

I actually want a minidsp for dirac though...the minidsp hd can do dirac with an upgrade...

Or I just buy this eventually (but that necessitates external amps for all speakers)....but that would leave me with not quite enough channels for home theatre use (currently running 7.1 channels but have 9.1 speakers already installed) So a minidsp 2x4 with dirac and the 8x8 with dirac would get me the 10 channels I would need all with dirac...
https://www.minidsp.com/products/dirac-series/ddrc-88a


Then there is also the fact I am running a yamaha rx-a1000 and would love some 4k or 8k support and the use of all 9 speakers..and the new denon avr-x3700h or 3600h gets great reviews over on audiosciencereview.com for their internal amps (LOVE THAT SITE AND THE OBJECTIVE DATA!!!!). It is the best rated avr over there right now. Also the Audyssey MultEQ XT32 seems to be a good contender against dirac (especially with the app control)
https://www.audiosciencereview.com/f...-review.15031/




Either way, my wife semi-ok'd the ultimax 18 purchase (just not this month)..I don't think I could swing $2k in hypex ncore amps to get the 9 channels I would need and the $1500 in dsps to get dirac..... She might not be ok with that since she just tolerates my audio love.....


I think a realistic obtainable plan for me (meaning getting my wife's approval) would be to get the Denon AVR, the ultimax (maybe could swing 2 but from where we listen there is only one real sweet spot for a sub anyway..also that I would go from 1500w max with a single to 1000w total for two due to impedance), get some type of dsp for the subs (I don't know if the denon does sub eq....my yamaha does not have that option).

Maybe then I could pick up a 2 channel (or two, 2 channels) ncore 502mp (350w x 2 @ 8ohms) and use that to drive the main speakers.

[Grinder]

Much of that is over my head. LOL I've got mostly ancient equipment, and haven't run surround in many years.

I can't speak for the miniDSP hd. I suspect those are cleaner than my entry level 2x4, but I really don't know.

Yeah, a single 18" Ultimax seems like the way to go ("Now, why didn't I think of that?" LOL), and I doubt you'll need more than that.

[MegaG]

OP, how did the Crown work out over time? I was wondering if something like the Crown would be a better choice over a plate amp.

I'm another Rythmik user, loved the sub until it stopped working, I still have to open it up and make sure its not just a loose wire but I know they had Servo Plate Amp failures from the time I picked up my DS1500 Kit

[Jdunk54nl]

It has been working very well. I convinced my wife to eventually let me buy two ultimax's (or something similar) to drive off of this. The 550w is plenty of power, now I just need to smooth it out for multiple locations. It really opens up the options of what I can purchase as far as future sub upgrades go.