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Author:	David McGown [ July 28th, 2021, 10:12 pm ]
Post subject:	Question on subwoofer amps
One of my Dayton subwoofer plate amps popped and started oscillating over the weekend. Shut it down but looking for replacements. It is an old SPA200 (replaced by the SPA250, same size). Figure it lasted this long I shouldn't complain. Anyway, i am looking at options, I have a pair of SPA250s on backorder at Parts Express, but was wondering whether it would be better to go with something like a Crown XLS series or Behringer Class D rack mounted amp that has DSP features for crossover. I would need something that has the flexibility to select a fairly low crossover frequency (40Hz), 4th order to blend with my fullrange speakers. Also intend on taking input from the speaker output (I can build an attenuating network). I figure Tom and others have experience in this area. Also, I am not sure if I would need a single stereo amp and have low pass capability in each channel, or would need to buy two amps and bridge them. Any suggestions would be appreciated! David

Author:

SoundMods [ July 28th, 2021, 10:28 pm ]

Post subject:

Re: Question on subwoofer amps

David McGown wrote:

One of my Dayton subwoofer plate amps popped and started oscillating over the weekend. Shut it down but looking for replacements. It is an old SPA200 (replaced by the SPA250, same size). Figure it lasted this long I shouldn't complain. Anyway, i am looking at options, I have a pair of SPA250s on backorder at Parts Express, but was wondering whether it would be better to go with something like a Crown XLS series or Behringer Class D rack mounted amp that has DSP features for crossover. I would need something that has the flexibility to select a fairly low crossover frequency (40Hz), 4th order to blend with my fullrange speakers. Also intend on taking input from the speaker output (I can build an attenuating network). I figure Tom and others have experience in this area. Also, I am not sure if I would need a single stereo amp and have low pass capability in each channel, or would need to buy two amps and bridge them. Any suggestions would be appreciated!

David

As it turns out -- I found that the older Dayton amps. did not like to drive impedance's below 4-ohms and they didn't have enough heat removal in terms of external heat sinks.

I believe their current products should drop in to your subs with no problems. In my case I added a 1-ohm resistor in series with my sub and added heat sinks. It kicks ass and takes names.

Attachments:

Eleganza_Dayton_Plate_Amp a.JPG [ 1.62 MiB | Viewed 5638 times ]

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Author:	FerdinandII [ July 28th, 2021, 10:43 pm ]
Post subject:	Re: Question on subwoofer amps
SoundMods wrote: David McGown wrote: One of my Dayton subwoofer plate amps popped and started oscillating over the weekend. Shut it down but looking for replacements. It is an old SPA200 (replaced by the SPA250, same size). Figure it lasted this long I shouldn't complain. Anyway, i am looking at options, I have a pair of SPA250s on backorder at Parts Express, but was wondering whether it would be better to go with something like a Crown XLS series or Behringer Class D rack mounted amp that has DSP features for crossover. I would need something that has the flexibility to select a fairly low crossover frequency (40Hz), 4th order to blend with my fullrange speakers. Also intend on taking input from the speaker output (I can build an attenuating network). I figure Tom and others have experience in this area. Also, I am not sure if I would need a single stereo amp and have low pass capability in each channel, or would need to buy two amps and bridge them. Any suggestions would be appreciated! David As it turns out -- I found that the older Dayton amps. did not like to drive impedance's below 4-ohms and they didn't have enough heat removal in terms of external heat sinks. I believe their current products should drop in to your subs with no problems. In my case I added a 1-ohm resistor in series with my sub and added heat sinks. It kicks ass and takes names. I see those film bypass caps in there, Walt......you can't fool us.

Author:	SoundMods [ July 28th, 2021, 10:47 pm ]
Post subject:	Re: Question on subwoofer amps
FerdinandII wrote: SoundMods wrote: David McGown wrote: One of my Dayton subwoofer plate amps popped and started oscillating over the weekend. Shut it down but looking for replacements. It is an old SPA200 (replaced by the SPA250, same size). Figure it lasted this long I shouldn't complain. Anyway, i am looking at options, I have a pair of SPA250s on backorder at Parts Express, but was wondering whether it would be better to go with something like a Crown XLS series or Behringer Class D rack mounted amp that has DSP features for crossover. I would need something that has the flexibility to select a fairly low crossover frequency (40Hz), 4th order to blend with my fullrange speakers. Also intend on taking input from the speaker output (I can build an attenuating network). I figure Tom and others have experience in this area. Also, I am not sure if I would need a single stereo amp and have low pass capability in each channel, or would need to buy two amps and bridge them. Any suggestions would be appreciated! David As it turns out -- I found that the older Dayton amps. did not like to drive impedance's below 4-ohms and they didn't have enough heat removal in terms of external heat sinks. I believe their current products should drop in to your subs with no problems. In my case I added a 1-ohm resistor in series with my sub and added heat sinks. It kicks ass and takes names. I see those film bypass caps in there, Walt......you can't fool us. Busted!

Author:	DaveR [ July 29th, 2021, 7:47 am ]
Post subject:	Re: Question on subwoofer amps
I use Crown XLS amps for subs these days. They're an excellent low cost high power solution. The fact that they're not mounted in the sub cabinet is a good thing for several reasons. However, if you would prefer to replace your plate amp with another I have an SPA250 that's looking for a home.

Author:	David McGown [ July 29th, 2021, 8:55 am ]
Post subject:	Re: Question on subwoofer amps
DaveR wrote: I use Crown XLS amps for subs these days. They're an excellent low cost high power solution. The fact that they're not mounted in the sub cabinet is a good thing for several reasons. However, if you would prefer to replace your plate amp with another I have an SPA250 that's looking for a home. I have a question concerning the DSP functionality on the Crown XLS amps. Crown does not seem to detail anything on this in the product literature. Can you set both channels on a single amp as low pass? What is flexibility to specify a crossover frequency? What is the slope (I have heard 48dB/octave, or eight order, but is 4th order available). Is there any provision for bass boost or equalization in the passband? Thanks. David

Author:	DaveR [ July 29th, 2021, 9:31 am ]
Post subject:	Re: Question on subwoofer amps
The manuals are available on-line which should give you the details you're looking for. You can download the first gen from here: https://www.crownaudio.com/en/products/xls-1000 And the current generation from here: https://www.crownaudio.com/en/products/xls-1002 Surprisingly, they don't give you the answers you're looking for. I checked my XLS 1502 and you can set it down to 30 Hz, but no slope information is provided. Given the low crossover frequency you're talking about the level control is likely to be all the bass boost you'll need, unless I'm missing something.

Author:	David McGown [ July 29th, 2021, 10:00 am ]
Post subject:	Re: Question on subwoofer amps
Actually, it appears they have a 4th order slope and can set down to 30Hz by 1/12 octave steps. The big question is whether both channels can be used independent of each other. This means I can use a single amp rather than two amps, each in bridged mode. David

Author:	David McGown [ July 29th, 2021, 8:48 pm ]
Post subject:	Re: Question on subwoofer amps
Well, I did enough research today to find out that a single Crown XLS amplifier in stereo should work with a pair of stereo subwoofers using the internal crossover. The crossover is adjustable in 1/12 octave steps, which is plenty fine for me. Parts Express updated their backorder date to mid-August (it was due in today), so I have cancelled the order and will buy a Crown XLS 1502 or 2002 (leaning towards the latter since it is a couple pounds heavier, which means a more robust design). I have to make some space in my equipment rack, but it should work just fine. I originally built these subs (over 20 years ago) powered from a seperate amplifier, no hole in the enclosure for a plate amplifier, it is just in a box I have attached on the back of each sub. So all I really have to do is make up voltage divider cables from each amp output to the input of the Crown, (the plate amps accepted high level inputs, which I prefer for integration). All, thank for the help.

Author:	David McGown [ July 31st, 2021, 2:25 pm ]
Post subject:	Re: Question on subwoofer amps
Picked up a Crown XLS 1502 at Washington Music Center this afternoon. Probably will order a miniDSP HD to do some LF equalization, but at least I can get something working with the Crown.

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