Thoughts on re-powering a Snell subwoofer

[lovinthehd]

I think you can use any amp you want. It is a ported sub which you can not Eq. You can not use DSP. So I would put a set of terminals on the back and use any amp 200 to 300 watt.

You need to be careful about bridging as that is a 4 ohm sub driver. So when bridged you need a speaker double the impedance an amp is rated for, or you will blow it. So for bridging you need a 2 ohm capable amp.

Not true, some ported subs use dsp to place a protective filter and you can of course apply eq if you want to (may not need to). I know you think that would be poor design on the protective hpf but it exists. Many plate amps come with such built in, too.

 

[TLS Guy]

Not true, some ported subs use dsp to place a protective filter and you can of course apply eq if you want to (may not need to). I know you think that would be poor design on the protective hpf but it exists. Many plate amps come with such built in, too.

That is true, but unless you blast it there will be no problem. If you want to blast it then a high pass filter at 25 Hz 12 db per octave, can easily be added. You can not Eq a ported sub like a sealed one. That will definitely damage it and make the driver decouple from the box.

 

[lovinthehd]

That is true, but unless you blast it there will be no problem. If you want to blast it then a high pass filter at 25 Hz can easily be added. You can not Eq a ported sub like a sealed one. That will definitely damage it and make the driver decouple from the box.

Still overstating things as usual. I didn't say you could eq it like you would need to with a sealed one either. Some do blast subs, sometimes unintentionally.

 

[TLS Guy]

Still overstating things as usual. I didn't say you could eq it like you would need to with a sealed one either. Some do blast subs, sometimes unintentionally.

The point I'm making is that if he uses an amp with enough power that can drive a 4 ohm load, then more likely than not he will be fine. That looks like a well made driver and I don't think a transient would blow it unless it was enormous. That sub has a 6 db point of 20 Hz, and so is designed for significant power down to 20 Hz. If it was me I would just use an appropriate power amp and not add anything further.

The problem you are describing is with subs that have an F3 above 30 Hz and sealed ones as they have Eq at 12 db per octave. So power becomes enormous as frequency is lowered. A typical sealed sub has an F3 of 50 Hz and often higher without Eq. So if you Eq it to 25 Hz then the drive power is over 10 times higher at 25 Hz than 50 Hz for the same spl. So at that point you have to put the bar up. A ported sub is totally different unless it has a high F3, and then you do have to prevent excess excursion from decoupling below f3.

Actually as I think about it, the fact that the 3 db point is 26 Hz and the 6 db point is 20 Hz tells me that the amp has no high pass filter.

 

[Shanman]

The Niles SI-245 power amp I have can't be bridged as a member eluded to, so I don't have anything to run it with. Unless I use one of the other 3 channels going unused on the Arcam, but I think I'll leave it be until I likely get the new plate amp.
The cheap plate amp that would fit perfectly was a Dayton, and reading reviews did not make me all warm and fuzzy.
https://www.amazon.com/Dayton-Audio-SPA250-Subwoofer-Amplifier/dp/B0070Z81MW/ref=gp_aw_ybh_a_4?_encoding=UTF8&psc=1&refRID=0GN4F9SMAGYPYMSW13BA

KEW was kind enough to put up a response graph of the Snell ISO300 in the other thread. It was the precursor to my sub and was pointed out mine should be at least as capable or better. Had a nice Flat response.

 

[lovinthehd]

The Niles SI-245 power amp I have can't be bridged as a member eluded to, so I don't have anything to run it with. Unless I use one of the other 3 channels going unused on the Arcam, but I think I'll leave it be until I likely get the new plate amp.
The cheap plate amp that would fit perfectly was a Dayton, and reading reviews did not make me all warm and fuzzy.
https://www.amazon.com/Dayton-Audio-SPA250-Subwoofer-Amplifier/dp/B0070Z81MW/ref=gp_aw_ybh_a_4?_encoding=UTF8&psc=1&refRID=0GN4F9SMAGYPYMSW13BA

Hard to go by Amazon reviews, often they're for more than the product listed (different models I see grouped together in the review section fairly frequently) let alone from people with any knowledge of the type of product or use. BASH plate amps aren't exactly known for quality either. The Niles may even work at low volume level temporarily....

 

[Shanman]

I think you can use any amp you want. It is a ported sub which you can not Eq. You can not use DSP. So I would put a set of terminals on the back and use any amp 200 to 300 watt.

You need to be careful about bridging as that is a 4 ohm sub driver. So when bridged you need a speaker double the impedance an amp is rated for, or you will blow it. So for bridging you need a 2 ohm capable amp.

I was going to bridge the amp, not parallel the speaker which I believe is a single voice coil. Bridging the 8ohm stereo Niles to mono would then output 4 ohm power, right?
Plus, the back of my Niles says stable to 2.67ohms min.

 

[Pogre]

I was going to bridge the amp, not parallel the speaker which I believe is a single voice coil. Bridging the 8ohm stereo Niles to mono would then output 4 ohm power, right?

I'm not a pro here, but I'm pretty sure when you bridge an amp it combines channels and halves the impedance of the driver? Wait for another answer either way. I might be wrong.

 

[WaynePflughaupt]

TLS guy beat me to it, but I was also going to suggest just installing some binding posts on the back panel and powering the sub with an outboard amplifier. There’s no shortage of excellent vintage pro-audio amps available on ebay. According to what I can find, the Bassis’ amplifier was only rated for 300 watts. Not hard to find a pro-amp that can do that at 4-ohms.

https://www.ebay.com/itm/Panasonic-RAMSA-WP-1400-2-Ch-Professional-Power-Amplifier-240W-CH-8-OHMS/323693813986?epid=1381275039&hash=item4b5da7a0e2:g:uWsAAOSwJj9cZIBg

https://www.ebay.com/itm/RAMSA-WP-9220-Stereo-Power-Amplifier-good-shape/254312884600?epid=904699249&hash=item3b363aa978:g:ojcAAOSwXFldPZgU

https://www.ebay.com/itm/Ashly-1800-Power-Amplifier-611W-2-Channel-Rack-Mountable/183875330702?_trkparms=ispr=1&hash=item2acfd2e28e:g:FIAAAOSwiHBdI5Jb:sc:FedExHomeDelivery!78404!US!-1&enc=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&checksum=1838753307029738e0e79e0148efb335ae19bb8911c9

https://www.ebay.com/itm/QSC-MX1500A-Professional-Stereo-Amplifier/254328897077?hash=item3b372efe35:g:iQcAAOSwTSldUdBY

https://www.ebay.com/itm/Rack-Mount-Crest-Audio-FA901-2-Channel-Power-Amplifier-225W-CH-8-OHMS/323401141153?hash=item4b4c35cba1:g:SXsAAOSw0qBbdzOj

Regards,
Wayne A. Pflughaupt

 

[Shanman]

Hard to go by Amazon reviews, often they're for more than the product listed (different models I see grouped together in the review section fairly frequently) let alone from people with any knowledge of the type of product or use. BASH plate amps aren't exactly known for quality either. The Niles may even work at low volume level temporarily....

I pretty much disregarded the Dayton when you mentioned the DSP built into the Snell amp was a factor to consider. I suppose I need to tighten up on terminology, but I assume DSP is not the same as a crossover point. It is signal processing to make the driver have a flat response with roll off at a certain point, etc?

 

[lovinthehd]

I pretty much disregarded the Dayton when you mentioned the DSP built into the Snell amp was a factor to consider. I suppose I need to tighten up on terminology, but I assume DSP is not the same as a crossover point. It is signal processing to make the driver have a flat response with roll off at a certain point, etc?

DSP simply stands for digital signal processing. It can take various forms, the dsp I was referring to was initially (in your other post) meaning that the original amp may have had a protective high pass filter and/or eq built in (and this was before I knew it was ported). In the case of a sealed sub many amps have a bit of boost in the lower frequencies to flatten response a bit. Some ported subs use a protective high pass filter to prevent over-excursion of the driver (and seeing the f6 of 20hz as TLS pointed out, don't think that's a particular concern now).

The Dayton 250 comes in a DSP version as well, with more features. Generally parts-express.com (a division of Dayton) is a better place to look at their products than Amazon, too. Dayton offers good quality in general and good customer service. I personally don't want plate amps, use external amps and dsp on my diy subs. I like Wayne's suggestion of looking for a used pro amp, altho be aware that fan noise on some can be bothersome in a typical living room installation (I use Crown XLS amps, very quiet).

 

[Shanman]

OK, so if I went the external amp route, I would take the low level output from the sub out on the Arcam, and connect to the low level input RCA's on the dedicated sub amp. Where would any crossover be coming from? Wouldn't I be sending a full range signal, or does the LFE out from the Arcam to feed the sub amp then become my low pass signal?

 

[lovinthehd]

OK, so if I went the external amp route, I would take the low level output from the sub out on the Arcam, and connect to the low level input RCA's on the dedicated sub amp. Where would any crossover be coming from? Wouldn't I be sending a full range signal, or does the LFE out from the Arcam to feed the sub amp then become my low pass signal?

Don't know what Arcam but typically avrs have bass management so you can determine your own crossover from speaker to sub....or just provide the LFE channel if that's all you want to play in the sub.

 

[Shanman]

Yes, the Arcam has the bass management, an AVR350 5 channel. Thanks, everyone- until today I didn't even think of using a dedicated amp to run the sub.

 

[lovinthehd]

Yes, the Arcam has the bass management, an AVR350 5 channel. Thanks, everyone- until today I didn't even think of using a dedicated amp to run the sub.

Hmmm....see post 5 in your first thread

 

[Shanman]

Indeed, I fixated on the DSP comment!

 

[Shanman]

....or just provide the LFE channel if that's all you want to play in the sub.

Mind elaborating on this? I am assuming you meant perhaps feeding more midbass frequencies to the sub? My Arcam AVR allows me to adjust the low pass crossover points from 40-130Hz. With Snell towers handling the midbass and upward duties, I would think that duplicating the midbass by a high crossover point would likely sound poor on a ported sub?

For anyone following- the plate amp replacement was a bust. Definitely taking the experienced recommendations to re-power externally.

In anticipation of purchasing an external sub amp, should I look for one with a dedicated volume control? Subwoofer adjustment vi a the Arcam remote is quickly accessed, so not needed? For the new sub amp, do I need an exact match to the 31dB gain of the Arcam?

 

[lovinthehd]

Mind elaborating on this? I am assuming you meant perhaps feeding more midbass frequencies to the sub? My Arcam AVR allows me to adjust the low pass crossover points from 40-130Hz. With Snell towers handling the midbass and upward duties, I would think that duplicating the midbass by a high crossover point would likely sound poor on a ported sub?

For anyone following- the plate amp replacement was a bust. Definitely taking the experienced recommendations to re-power externally.

In anticipation of purchasing an external sub amp, should I look for one with a dedicated volume control? Subwoofer adjustment vi a the Arcam remote is quickly accessed, so not needed? For the new sub amp, do I need an exact match to the 31dB gain of the Arcam?

LFE is the .1 channel content (in content that has such, music and multich music on dvd/bluray etc), some prefer that alone goes to the sub. Bass management would add to that information going to the sub by crossing over frequencies from your speakers to sub (a crossover being both a low pass for your sub and a high pass for your speakers, it's where the two filter slopes "cross"). Some bass management can add the information to both speakers and sub (called Double Bass or LFE+Main etc).

Crossover is generally suggested at 80hz as a starting point. Not sure what you're calling midbass frequencies. Do you want your speakers to play full range or use a crossover and limit the bass to the speaker in favor of using the sub?

A sub amp should have a gain control to match up your avr's pre-out level to the sub's amp, but it may be labeled volume (and generally once setup you would only use the avr to set level as it is more precise/repeatable in most cases). Similar to how some subs have only a low pass filter labeled crossover. Confusing but they think it's easier on the general consumer I suppose. No an exact match isn't necessary for the max gain of your Arcam.

Hope that helps.

 

[Shanman]

LFE is the .1 channel content (in content that has such, music and multich music on dvd/bluray etc),some prefer that alone goes to the sub. Bass management would add to that information going to the sub by crossing over frequencies from your speakers to sub (a crossover being both a low pass for your sub and a high pass for your speakers, it's where the two filter slopes "cross"). Some bass management can add the information to both speakers and sub (called Double Bass or LFE+Main etc).

Crossover is generally suggested at 80hz as a starting point. Not sure what you're calling midbass frequencies. Do you want your speakers to play full range or use a crossover and limit the bass to the speaker in favor of using the sub?

A sub amp should have a gain control to match up your avr's pre-out level to the sub's amp, but it may be labeled volume (and generally once setup you would only use the avr to set level as it is more precise/repeatable in most cases). Similar to how some subs have only a low pass filter labeled crossover. Confusing but they think it's easier on the general consumer I suppose. No an exact match isn't necessary for the max gain of your Arcam.

Hope that helps.

Fantastic, thank you. The Arcam has the capabilities for me to choose "Large" (Pure stereo- all audio sent to front L+R),"Large+Sub" (Pure stereo L+R and extracted bass sent to sub, and "Sat+Sub" (not applicable, using towers). The sub+sat setting would be the only setting that combines the low and high pass scenario where the 2 filter slopes cross and blend which I'm not going to use. I would imagine letting the full range towers naturally roll off and having the sub run 80Hz and down would be a good start. I am contemplating using the Zone 2 assignment (channels 6&7)on the Arcam to bi-amp the Snell towers as my manual says it is OK to do so.

In regards to midbass, my brain goes to the 100hz-500hz spectrum. I was learning how some here are running some subs for "midbass" duty, a some subs for the sub-bass. I am ignorant to what this means- I guess one sub that runs 500hz and down, and another that runs 80hz-ish and down?

Looking at the Crown XLS1002, 350 rms @ 4ohms which seems like a good driver match on paper for my 2.1 music set up. I have zero interest in going used on a sub amp. While the Arcam was a super thrift shop deal, I've have been chasing 60hz hum gremlins, and I don't need two. It's already been to the shop where they replaced the "failing power supply", yet the hum still shows it's ugly head on occassion. I'm reading up on other sources that could be the issue- another tangent for another day....


Anyone want to steer me towards some good binding posts to attach to the back of the dead plate amp?

 

[lovinthehd]

Fantastic, thank you. The Arcam has the capabilities for me to choose "Large" (Pure stereo- all audio sent to front L+R),"Large+Sub" (Pure stereo L+R and extracted bass sent to sub, and "Sat+Sub" (not applicable, using towers). The sub+sat setting would be the only setting that combines the low and high pass scenario where the 2 filter slopes cross and blend which I'm not going to use. I would imagine letting the full range towers naturally roll off and having the sub run 80Hz and down would be a good start. I am contemplating using the Zone 2 assignment (channels 6&7)on the Arcam to bi-amp the Snell towers as my manual says it is OK to do so.

In regards to midbass, my brain goes to the 100hz-500hz spectrum. I was learning how some here are running some subs for "midbass" duty, a some subs for the sub-bass. I am ignorant to what this means- I guess one sub that runs 500hz and down, and another that runs 80hz-ish and down?

Looking at the Crown XLS1002, 350 rms @ 4ohms which seems like a good driver match on paper for my 2.1 music set up. I have zero interest in going used on a sub amp. While the Arcam was a super thrift shop deal, I've have been chasing 60hz hum gremlins, and I don't need two. It's already been to the shop where they replaced the "failing power supply", yet the hum still shows it's ugly head on occassion. I'm reading up on other sources that could be the issue- another tangent for another day....


Anyone want to steer me towards some good binding posts to attach to the back of the dead plate amp?

Large merely means "do not use bass management". Small means "use bass management". Whether you have a tower doesn't really matter, they are "sats" when used with a crossover and a sub. It's a matter of preference to duplicate part of the bass band in the speaker and sub, personally I don't do that (even with towers, as they're not as capable as my subs, not many towers are).

Passive bi-amping is a waste of wire IMO. Try this article https://www.audioholics.com/frequent-questions/the-difference-between-biamping-vs-biwiring

Sounds like you're talking about use of mid-bass modules...some subs don't do a lot above 100hz either....better ones have more range but not that many work well beyond 2-300hz. I wouldn't bother myself.

I use Crown XLS1500s on my diy subs...good amps. Lots of binding posts on parts-express.com. 60hz hum may be you have a ground loop hum issue....try this article https://www.audioholics.com/home-theater-connection/ground-loops-eliminating-system-hum-and-buzz

FWIW sometimes a picture of a crossover helps understand what it's doing (the slopes may not match yours, tho)