I have a couple of 10" AV123 subwoofers with replacement Dayton SPA250 plate amps. I'm using a miniDSP 2x4 for the subs only, crossed over at 48Hz Low Pass, LR2.
The Daytons are Class AB, rated for 155W@8Ω. Power seems to be sufficient, I've never heard them clip, but I'm wondering if I could get better sound quality by replacing them with an inexpensive stereo amp. The plate amps have a 12dB/octave infrasonic filter at 20Hz which cannot be bypassed. I don't need this filter, as I will continue to use the miniDSP. The plate amps' low pass filter also cannot be bypassed, only set at its highest frequency (180Hz LP, 24dB/octave). I assume these filters are adding some time delay? The subs are below and outside the monitors, and cannot be relocated or moved closer to the listening seat.
I would like your opinion on whether a base level pro amp like the Crown XLi 1500 (Class AB, 330W@8Ω) or similar would provide faster/tighter bass.
The Daytons are Class AB, rated for 155W@8Ω. Power seems to be sufficient, I've never heard them clip, but I'm wondering if I could get better sound quality by replacing them with an inexpensive stereo amp. The plate amps have a 12dB/octave infrasonic filter at 20Hz which cannot be bypassed. I don't need this filter, as I will continue to use the miniDSP. The plate amps' low pass filter also cannot be bypassed, only set at its highest frequency (180Hz LP, 24dB/octave). I assume these filters are adding some time delay? The subs are below and outside the monitors, and cannot be relocated or moved closer to the listening seat.
I would like your opinion on whether a base level pro amp like the Crown XLi 1500 (Class AB, 330W@8Ω) or similar would provide faster/tighter bass.
I can't delay the upper frequencies because the monitors are not running through the miniDSP, they are unfiltered, roll off naturally at 12dB/octave (sealed).
When I say "fast bass" I am referring to fast transients, i.e. no time delay, quick risetime, no overhang.
And box alignment also, sealed has the lowest group delay, then TL types, then BR and then horns. But sealed are hard to get real low in frequency.
But an amp won't make the difference, it's the driver(motor) and the enclosure who do that. Plate amps or pro amps won't make a difference on that.
Sure, and also about cabinet construction, but IME, the amp also matters. I have a pair of Meitner 50wpc stereo amps and a pair of 100W monoblocks. The tighter bass with the monoblocks is obvious compared to the 50W amps, either pair driving my 89dB/W/m monitors. I believe this is strictly due to current capability, as neither is approaching rated power in my room.
Definitely something to consider.
The subs got consistently good reviews when they were in production:
Product Review
Unfortunately virtually all of the original plate amps died an early death.
Yet here you are asking how to make it sound faster, tighter, more controlled. In general a sealed sub has all these qualities so it's possible the room is having a negative impact on it, maybe you are hearing a reflection/reverberation that is blurring everything.
My experience :
At one point I used the Dayton SPA 250, although it worked well, it had a strange behavior in the AUTO ON section (automatic power on when detecting an audio signal). It works when it wants, I couldn't fix it and Dayton replied that they would repair it free of charge, but I'm a bit far to send them to you.
So it was left for HT use only and since I wanted to experiment with stereo bass (I guess the OP has a plate amp for each cabinet) I bought a stereo PA amplifier for audio use only (Bheringer NX3000D, built-in DSP. )
It is true that it was very noisy, but it is quite easy to change the fan for a silent one, I did it and now it is inaudible. There are explanatory videos on YT of how to do it. It's what I got here, I'm not saying it's the only option, but its use is widely publicized among audiophiles. (I suppose because of its very accessible price)
The DSP of the Bheringer is very versatile, although by default the software also has the subsonic filter configured at 20 hz, I imagine that is because the vast majority of PA speakers are ventilated and are not sealed. More sub-bass extension can be given by adjusting the parametric equalizer in the software. I did not do it because I am very happy with the sound achieved by 450 watts RMS per channel in sealed 18 "speakers.
My opinion is that although a high performance and quality loudspeaker in a suitable construction (TL / BR, etc) achieves a bass extension below 20 hz, the cost is much higher than a class D amplifier with DSP, which allows a very precise fit with various types of filters and respective slopes.
( I use Butterworth 18 Db / octave)
Hope my opinion helps.
At one point I used the Dayton SPA 250, although it worked well, it had a strange behavior in the AUTO ON section (automatic power on when detecting an audio signal). It works when it wants, I couldn't fix it and Dayton replied that they would repair it free of charge, but I'm a bit far to send them to you.
So it was left for HT use only and since I wanted to experiment with stereo bass (I guess the OP has a plate amp for each cabinet) I bought a stereo PA amplifier for audio use only (Bheringer NX3000D, built-in DSP. )
It is true that it was very noisy, but it is quite easy to change the fan for a silent one, I did it and now it is inaudible. There are explanatory videos on YT of how to do it. It's what I got here, I'm not saying it's the only option, but its use is widely publicized among audiophiles. (I suppose because of its very accessible price)
The DSP of the Bheringer is very versatile, although by default the software also has the subsonic filter configured at 20 hz, I imagine that is because the vast majority of PA speakers are ventilated and are not sealed. More sub-bass extension can be given by adjusting the parametric equalizer in the software. I did not do it because I am very happy with the sound achieved by 450 watts RMS per channel in sealed 18 "speakers.
My opinion is that although a high performance and quality loudspeaker in a suitable construction (TL / BR, etc) achieves a bass extension below 20 hz, the cost is much higher than a class D amplifier with DSP, which allows a very precise fit with various types of filters and respective slopes.
( I use Butterworth 18 Db / octave)
Hope my opinion helps.
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My listening room has a concrete floor and ceiling, 3 concrete walls furred with drywall, and irregular in shape. I use REW auto-EQ and then fine-tune, which results in pretty flat response below 300 Hz, with a subtle house curve.
I am not complaining about the bass now, but almost anything can be improved. My question is, would a pro amp sound better than my plate amps, especially given the extra filters that I can't bypass. I have put you down as a clear "no". Thanks for your thoughts.
I don't use auto-on with the SPA250 for the reason you mentioned, it is unreliable. The plate amps are powered at all times.
It seems the Behringer amp incorporates the capabilities of the miniDSP 2x4, but maybe not the REW auto-EQ feature? Integration of REW in the miniDSP is very handy and powerful, allowing direct upload the filters to the miniDSP. I don't think I would be able to achieve the same results with manual filter design.
I imagine it would be pretty hard to compare the sound of the SPA250 vs. the Behringer, since the pro amp has far better filtering capabilities.
By better, do you mean superior sound quality? Mostly I hear that Class AB is preferred to Class D for SQ, but some better Class D amps are comparable to AB (e.g. Benchmark).
Are you saying the XLS has a silent fan, the XLi does not? I expect the fans would be less likely to trigger with a Class D amp.
What about my situation, with plate amps that are doing the job currently. Do you believe there would be any SQ improvement with an inexpensive pro amp?
As per the above discussion, I am using Dayton SPA250 plate amps. They have a:
- 20Hz infrasonic filter that cannot be turned off
- LR4 crossover at 180 Hz that cannot be bypassed
- switchable 6dB bass boost at 30Hz
Can someone tell me how these features are implemented in a Class AB plate amp? Are these analog circuits or is there an AD to DA conversion?
I cross over to the plate amps at 48Hz LR2, so I am about 2 octaves away from the 180Hz LR4 in the plate amps. I value the infrasonic filter. I have pretty flat response down to 24Hz, below which it drops like a stone. I am happy with this FR. I don't care about Home Theater or subterranean sound effects, just music.
My question is whether the unnecessary processing in the plate amps negatively impacts SQ, and whether pro amps will sound better than plate amps.
- 20Hz infrasonic filter that cannot be turned off
- LR4 crossover at 180 Hz that cannot be bypassed
- switchable 6dB bass boost at 30Hz
Can someone tell me how these features are implemented in a Class AB plate amp? Are these analog circuits or is there an AD to DA conversion?
I cross over to the plate amps at 48Hz LR2, so I am about 2 octaves away from the 180Hz LR4 in the plate amps. I value the infrasonic filter. I have pretty flat response down to 24Hz, below which it drops like a stone. I am happy with this FR. I don't care about Home Theater or subterranean sound effects, just music.
My question is whether the unnecessary processing in the plate amps negatively impacts SQ, and whether pro amps will sound better than plate amps.
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For all :
First I make it clear that I cannot comment on REW or Mini DSP, I have never used them nor do I know people who use them. (They are all somewhat older, - like me -, we have another disposition for what we see as modern technological complications).
I just didn't consider them necessary given the good behavior of my living room.
First I make it clear that I cannot comment on REW or Mini DSP, I have never used them nor do I know people who use them. (They are all somewhat older, - like me -, we have another disposition for what we see as modern technological complications).
I just didn't consider them necessary given the good behavior of my living room.
Correct, it is fixed, and it would not be necessary for sealed cabinets, but I think they put it in order not to have complaints from users who have ventilated cabinets and are damaged by over excursion of the cone .
I do not understand what your question is here.
It is switchable between 40 and 180 hz.
I experimented (when using it for music) with the gain and cutoff frequency, until I achieved adequate overlap with my satellite speakers.
As they are very large and respond well up to 40 hz, but since I place them very far from the rear walls, normally the filter left it at around 60 Hz, which covered the extension that I was missing.
The SPA250 does not have frequency markings between the two extremes.
Point against for Dayton there, the same as with the phase selector, without intermediate points, although the latter is not so problematic.