agreed. usually you don't want to put any resistors in line with the woofer, right?. BTW, the speakers are my design and I use mills or mundorf resistors to pad down when needed. high now I have them running wide open!! I was hoping an amp might have some adjustment.. Just got a recommendation from someone about ART SLA-2. Looks to be pro sound. Not sure I want to go that route unless I know for sure its good.
Is my amp the problem?
I recently decided to bi-amp my speakers so I purchased a crown xls 1002. (225w 8 ohm). I am driving a 10 woofer. It sounds horrible. I can't seem to get it to put out much power despite its rating even when I make all the right adjustments. Its a class D amp. Is that my problem? It just doesn't seem to have any Ba**s. Lol. Advice is appreciated.
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The input impedance of the ART (Applied Research and Technology) SLA-2 is 22K unbalanced and 44K balanced, the latter probably corresponding to 22K per leg. Too low to be optimal, or even close to being optimal, when driven in parallel with your Modwright amp by the LS100. Also, the fact that its rated maximum power into 4 ohms is only 40% higher than its rating into 8 ohms says nothing positive about the robustness of its design. I’ve used some other ART products for non-audiophile purposes, and in those non-critical applications I found them to be an excellent value. But I suspect that in a high quality audiophile-oriented system they would likely be disappointing, even if no impedance or other technical issues were present. Regards, -- Al |
The Parasound amps are the only stereo audiophile amps I have seen that have a volume/level control. The older THX certified multi-channel amps all had level controls, and pro audio amps have level controls. There's a Parasound A23 on Audiogon for $699, but honestly I think you'll get better control with the two XPA-100 monoblocks (and cheaper). You could always wire an Alps potentiometer directly into your RCA interconnect for the woofer amp. It looks like there are cheap passive volume preamp for like $50-60 available. I haven't used ART stuff, but I kind of view them as a lower end item, like Behringer. Not bad, per say, but definitely inexpensive, with Crown and QSC being better quality (but more expensive also). |
Wow, I thought we were looking at cheaper alternatives, lol. I would avoid the Adcom. I had an Adcom GFA-545. It was on the warm/slow side and sounded dirty/smeared when compared to other better amps. The Emotiva XPA-2 is definitely a contender if you are considering this and definitely better than the XPA-100 monoblocks. Very strong amp. I do not have any direct experience with the Wyred 4 Sound (or any other ICE based Class D amp). Eric Squires likes the w4s, but I cannot give you an opinion on how well it will control the woofer. It does have a radical 100k ohms input impedance! |
Emporium: - Go to Emotiva’s main website http://emotiva.com/ - Click on "Community" in the menu bar at the top - Scroll all the way almost to the end. There should be a forum call "The Emporium" - Scroll down. The topic/listing should still be on the first page and titled "XPA-100 GEN 2 PAIR BNIB". |
OK so today I got some improvements. I got the good caps from Modwright and installed in my KAW 100SE. That sings sweet now. I had the woofer amp plugged into a power conditioner, I plugged them directly into the wall. I worked with the Xo points/slopes and now it's beginning to sound much better. Not perfect but it has come a long way. Now i still have some caps Dan sent me to install on the LS100 that he says will improve the bass response. I'll do that tomorrow. Stay tuned :) |
Which crossover are you using? minDSP or Antimode 2.0? The Antimode is probably a much better unit then the miniDSP (as it’s 6 times as expensive, lol.), but keep in mind it is still a DSP (which means A/D -> DSP crossover -> D/A). If you like the way it sounds, I’m sure it will benefit strongly from a hefty 12V linear power supply such as this: http://www.ebay.com/itm/121970182193?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT Or many others that are available. It's hard to say if this will be better than a Bryston crossover, but I know you're trying less expensive options first. |
Aux, right now I have a mindsp in the circuit. Since I am in an audio club I am fortunate to have loaner equipment available. So today someone lent me a Dahlquist LP-1. I know vintage Lol! It has a higher input impedance so I want to what the effect of that is. On a related note,at this meeting the host was using GR Research dual 12 OB woofers with the A370PEQ amps. It sounded very good. I like OB stuff. However it is around 3K for that alone. Ultimately I would like to build a pair next summer. Hopefully I can save some money DIY. |
That power supply is pretty hefty. The specs are 4.16 amp if you are doing the +12V DC model. This is fine if you are powering a several items like the miniDSP (which is very low current draw and uses basic op amps). It's fine even for adding Antimode 2.0 into the mix. This power supply has a lot of capacitance. The capicators they use could be better, but the price is right for what they give you. If you need a split power supply (i.e. +15V / -15V), then you'll need a different power supply. |
Have not heard that exact amp but have heard Crown Class D amps at the gym and I own other Class D amps. One thing is all Class D amps have very high damping factor including that one and the ones I use. Good ones do bass in particular extremely well, better than most anything else. Hence their popularity for use in powered subwoofers. When I first heard mine, I thought bass was gone also in comparison but turned out to just be more dimensional, articulate and clean in stark comparison to prior which was more towards stereotypical "one note" fatter bass which many may be used to and may seem like more or better but is not IMHO. |
almarg 2)The miniDSP 2x4 has a very low input impedance of 6K.I'm going through the same impedance woes, with yet to arrive a Minidsp 2 x 4 HD to do some bass (<150hz) only experiments with, it's 10kohm input, a little higher than the 2x4. I sent a email off to tech dept of mini dsp to see if the analogue inputs are a fet based input, if so then "maybe" the 10kohm smd load resistors can be swapped out for >50kohm? This should be an easy way out if the source has high output impedance. Cheers George |
