# Crest Audio CM2208



## NBPk402

Does anyone know if these are any good? Are the fans noisy?


----------



## NBPk402

I ordered 2 of these beasts...we will see how quiet they are. I got a great deal on them as the MSRP is $2500 each, with street price being $1700 each. I got them for $295 each shipped!
He still has more left if anyone is interested.
http://www.ebay.com/itm/252322877131?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT

Specs: Rated power bridge mode 8 Ohms: 320 Watts
Rated power bridge mode 140V: 460 Watts
Rated power (1 x 4 Ohms): 160 Watts
Rated power (1 x 8 Ohms): 240 Watts
Rated power 70.7V (24 Ohms): 230 Watts
Rated power (8 x 4 Ohms): 150 Watts
Rated power (8 x 8 Ohms): 210 Watts
Rated power (8 x 70.7V): 170 Watts
Minimum load impedance: 4 Ohms
Frequency response (HPF off): 5 Hz - 20 kHz; -1 dB at 1 Watt (8 Ohm load)
T.H.D.: <0.02% @ rated power, 1kHz (70.7V)
Input CMRR: >-60 dB @ 1 kHz
Crosstalk: >-60 dB @ 1 kHz at rated power @ 8 Ohms
Hum and noise: >-97 dB, below rated output, 22Hz - 22kHz
Damping factor (8 Ohms): >200:1 @ 20 Hz - 1 kHz
Input sensitivity: .775V (0 dBu setting)
Voltage gain: x40 or 0 dBu (x90)
Input impedance: 20 k Ohms balanced, 10 k Ohms unbalanced
Current Draw @ 1/8 power: 4.0 Amps
Current Draw @ 1/3 power: 8.0 Amps
Current draw @ idle: <2 Amp
Thermal emission @ 1/8 power: 724 BTU/hr
Thermal emission @ 1/3 power: 947 BTU/hr
Class: D
Country of manufacture: United States

Cooling: Variable speed, front panel mounted, front-to-side airflow
Controls: 8 channel input signal attenuators‚ 8 channel HPF select switches, 8 channel gain select switches
Indicators: 8 clip‚ 8 signal‚ 8 protect, 1 power
Protection: Over-temperature‚ DC‚ turn on/off transients‚ subsonic‚ short-circuit, over-current
Connectors Input: Eight 3-position Euro-style detachable terminal blocks
Connectors output: Eight 2-position Euro-style detachable terminal blocks
Construction: 16-gauge steel-reinforced with 12-gauge rack ears
Dimensions: 8.84 cm x48.26 cm x 43.31 cm (3.5” x 19” x 17.05)
Net weight: 16.5 kg. (36.5 lbs.), Gross weight: 17.2 kg. (38 lbs.) 



http://www.peaveycommercialaudio.com/cache/865.pdf


----------



## Tonto

Hey, that looks like a really good deal. I'm not familiar with those connectors. Are they easy to come by?


----------



## NBPk402

Tonto said:


> Hey, that looks like a really good deal. I'm not familiar with those connectors. Are they easy to come by?


They are Phoenix connectors, and go for $1-$10 each. I contacted the seller and he included all I would need. I prefer XLRs but my friend said XLRs are only good for removing and re-installing, where as these are for leaving connected. My MiniDSP DDRC-88A has them too but theirs are in multi connector blocks (4 or 8 per block I believe). What I have read about the Crest Audio amps is the early ones were made by Electro Voice, and the newer ones are made by Peavey. The ones I am getting are the ones EV made I believe.

I am really anxious to get these hooked up and see how they sound. They have been shipped via USPS so it will be almost 2 weeks before i get them (if the tracking info is correct). Once I get them I am going to make sure they work, and then look at fan noise to see if it will be an issue before I shove them into the rack.


----------



## lovinthehd

Thanks for the tip, I picked up one, too....for the price and number of channels a no-brainer. Curious, what is it about this amp design that creates less output at 4 ohm than 8 ohm? I haven't seen that before but assume this is somewhat related to the 70V capability?


----------



## NBPk402

lovinthehd said:


> Thanks for the tip, I picked up one, too....for the price and number of channels a no-brainer. Curious, what is it about this amp design that creates less output at 4 ohm than 8 ohm? I haven't seen that before but assume this is somewhat related to the 70V capability?


I don't know... I am thinking it has to do with the power supply, but that is just a guess. I am assuming this from hearing years ago that a real good power supply would double the power when you halved the impedance. I am not an electrician though. Everything I have read about their amps has been good, and the price was great so I decided to go with it. My speakers are all 8ohm except for the horns (which are 112db), so I figure I am safe. 

Mine won't arrive for 2 weeks according to the tracking info, so you might be getting yours sooner...depending on where you live (I am in Northern California). Post up what you think of it when you get it! :T


----------



## lovinthehd

ellisr63 said:


> I don't know... I am thinking it has to do with the power supply, but that is just a guess. I am assuming this from hearing years ago that a real good power supply would double the power when you halved the impedance. I am not an electrician though. Everything I have read about their amps has been good, and the price was great so I decided to go with it. My speakers are all 8ohm except for the horns (which are 112db), so I figure I am safe.
> 
> Mine won't arrive for 2 weeks according to the tracking info, so you might be getting yours sooner...depending on where you live (I am in Northern California). Post up what you think of it when you get it! :T


My ETA is between 4/22 and 4/30....used to be in norcal, now in SE Orygun. Even if its got a noisy fan I've got an app for it and if quiet then a few other options....


----------



## NBPk402

lovinthehd said:


> My ETA is between 4/22 and 4/30....used to be in norcal, now in SE Orygun. Even if its got a noisy fan I've got an app for it and if quiet then a few other options....


What is the app that will quiet the fans? What are the other options?


----------



## NBPk402

I sent Crest Audio an email to find out why the 4 ohm is less power than the 8 ohm... I will post up their response.


----------



## NBPk402

Here is the manual for the amp.


----------



## DqMcClain

I might pick one of these up as well... It would probably work out well in place of my ancient Rane MA6. As for noisy fans, if might very well be possible to replace the fan with something quieter, especially if you're running considerably below the ratings as I would likely do.


----------



## NBPk402

DqMcClain said:


> I might pick one of these up as well... It would probably work out well in place of my ancient Rane MA6. As for noisy fans, if might very well be possible to replace the fan with something quieter, especially if you're running considerably below the ratings as I would likely do.


He is selling them for a couple hundred below what everyone else is and they appear to be in very good condition.


----------



## lcaillo

I am curious to see what Crest says. They really don't say much about the amplifier design or architechture in their documentation.


----------



## NBPk402

lcaillo said:


> I am curious to see what Crest says. They really don't say much about the amplifier design or architechture in their documentation.


I noticed that some of their other amps do have more power in 4 ohm than 8 ohm.


----------



## lovinthehd

I assume it has something to do with them not needing a change in settinging changing from 70V use but haven't found an explanation.....did one of you actually contact Crest about this?


----------



## NBPk402

lovinthehd said:


> I assume it has something to do with them not needing a change in settinging changing from 70V use but haven't found an explanation.....did one of you actually contact Crest about this?


I sent them an email...we will see what they say. :T


----------



## NBPk402

This is their response.. 

"The CM 2208 has it's output optimized for an 8 ohm load when used as a low Z amplifier. The output power will be current limited and is reduced when connected to a 4 ohm load to prevent overload/overheating. "


----------



## lcaillo

It would be interesting to know more about how they accomplish this.


----------



## NBPk402

lcaillo said:


> It would be interesting to know more about how they accomplish this.


It would be, but I doubt they would tell us. I have yet to even find a picture of the internals for this one. If the fans turn out to be noisy I will pop the cover...I might even pop the cover just to see what is under it.


----------



## NBPk402

lovinthehd said:


> My ETA is between 4/22 and 4/30....used to be in norcal, now in SE Orygun. Even if its got a noisy fan I've got an app for it and if quiet then a few other options....


My ETA moved from Friday to today. I almost didn't get mine today as the UPS driver drove by my house and down another street. I hopped in my car and chased him down.  Wait until you see how he packed them... I have never seen anyone pack like this and I will do the same for my stuff that i don't have original boxes for. He made a wood frame That sandwiched the rack mounts between it so there is almost zero chance of it being damaged from the sides. For the top and bottom he used plenty of bubble wrap and there was zero damage. Both units are like new!

I have only powered them up to check for fan noise so far... The fans are noisier than I want so it looks like there will be some mods (after the amps are tested for sound). When you get yours let me know what you are going to do for the fan noise, please.


----------



## lovinthehd

ellisr63 said:


> My ETA moved from Friday to today. I almost didn't get mine today as the UPS driver drove by my house and down another street. I hopped in my car and chased him down.  Wait until you see how he packed them... I have never seen anyone pack like this and I will do the same for my stuff that i don't have original boxes for. He made a wood frame That sandwiched the rack mounts between it so there is almost zero chance of it being damaged from the sides. For the top and bottom he used plenty of bubble wrap and there was zero damage. Both units are like new!
> 
> I have only powered them up to check for fan noise so far... The fans are noisier than I want so it looks like there will be some mods (after the amps are tested for sound). When you get yours let me know what you are going to do for the fan noise, please.



My tracking shows ETA tomorrow via fedex.....and I won't be home.....I saw our UPS driver in town today and told him to bring the speakers I'm expecting down to the shop I'm doing some parttime work at....will leave a note for the Fedex guy, hopefully he will do the same. Glad to hear they're well packed (having spent most of my life in the freight business)! Will let you know what I think about the fans soon....did you perhaps put an spl meter on it for a reading?


----------



## NBPk402

lovinthehd said:


> My tracking shows ETA tomorrow via fedex.....and I won't be home.....I saw our UPS driver in town today and told him to bring the speakers I'm expecting down to the shop I'm doing some parttime work at....will leave a note for the Fedex guy, hopefully he will do the same. Glad to hear they're well packed (having spent most of my life in the freight business)! Will let you know what I think about the fans soon....did you perhaps put an spl meter on it for a reading?


Mine was via UPS...surprised yours is via FedEx. I used a app on my phone to measure it. It came out as 82db with one on and 86db with both on. The measurement was about a foot in front of the amps.


----------



## lovinthehd

ellisr63 said:


> Mine was via UPS...surprised yours is via FedEx. I used a app on my phone to measure it. It came out as 82db with one on and 86db with both on. The measurement was about a foot in front of the amps.


Yow that's loud. What'd you need to do to get both to come on? 

Maybe fedex cheaper for single package....or he just spreads it around....


----------



## NBPk402

lovinthehd said:


> Yow that's loud. What'd you need to do to get both to come on?
> 
> Maybe fedex cheaper for single package....or he just spreads it around....


The fans are constant... I had thought they were variable, but apparently only the newer ones are. It might be as simple as replacing them with a newer fan, to quiet them down. Post up how yours is.


----------



## lovinthehd

ellisr63 said:


> The fans are constant... I had thought they were variable, but apparently only the newer ones are. It might be as simple as replacing them with a newer fan, to quiet them down. Post up how yours is.


Just unboxed it, agree this guy packs well! I just plugged it in to AC to make sure it runs, fans aren't as loud as I expected after your post, but not as friendly as a Crown XLS Drivecore amp either. I didn't put an spl meter to it, will later. Suppose that was just first level of fan, tho. I'll play more with it soon but not sure I'll bother with a fan mode for that noise level, at least until such time as I may want to bring it into the living room. I'll open it up later and see what they look like and what options might be. Nice bit of amp for $300 in any case, thanks for the tip.


----------



## NBPk402

lovinthehd said:


> Just unboxed it, agree this guy packs well! I just plugged it in to AC to make sure it runs, fans aren't as loud as I expected after your post, but not as friendly as a Crown XLS Drivecore amp either. I didn't put an spl meter to it, will later. Suppose that was just first level of fan, tho. I'll play more with it soon but not sure I'll bother with a fan mode for that noise level, at least until such time as I may want to bring it into the living room. I'll open it up later and see what they look like and what options might be. Nice bit of amp for $300 in any case, thanks for the tip.


When i measured the fan noise I did it from the front of the amp as that is where it appeared loudest. When you get a chance, can you measure the noise on yours...maybe mine are louder. T


----------



## lovinthehd

Since you used a phone app I can do that easily enough....at 1 ft I got readings in 58-60 range depending how I oriented the phone, at around a meter away it dropped to 50-52 range. I had originally oriented it sideways on my workshop bench to make it easier to plug in....altho I knew it was louder at the front, turning it around did raise my eyebrows just a bit more  Might need to look into that fan mod sooner than later


----------



## NBPk402

lovinthehd said:


> Since you used a phone app I can do that easily enough....at 1 ft I got readings in 58-60 range depending how I oriented the phone, at around a meter away it dropped to 50-52 range. I had originally oriented it sideways on my workshop bench to make it easier to plug in....altho I knew it was louder at the front, turning it around did raise my eyebrows just a bit more  Might need to look into that fan mod sooner than later


Sounds like mine def needs new fans.


----------



## lovinthehd

ellisr63 said:


> Sounds like mine def needs new fans.


Mebbe like laptops its just dust accumulation?


----------



## NBPk402

lovinthehd said:


> Mebbe like laptops its just dust accumulation?


The filter looked clean...


----------



## NBPk402

Just opened up the amp to look at the fan... Still have to pop the pins out for the cardboard tunnel/shield.







[/URL][/IMG]


----------



## NBPk402

I ended up also removing the faceplate to get to the fan. Here is the fan







[/URL][/IMG]

Any ideas on one that would be quieter?


----------



## DqMcClain

I have ARCTIC F8 PWM PST fans in my HTPC chassis, and F10 fans as thermal exhaust for my rack cutout. They aren't completely silent, but they offer a very good ration of noise-to-airflow. I've also been happy with CoolerMaster Sickle-Flows, but I think the Arctic's beat them in noise-to-flow ratio in the 80mm category. (I'm not even sure at the moment if CoolerMaster makes that series in 80mm) 

BONUS POINTS: The Arctics are on Amazon Prime.

EDIT: Looking closer at that pic, I see the motor on the fan says 5V. The F8 comes in a non-PWM controlled version that will run at 5V, but the airflow at that setting is not quoted. I found another fan by Gdstime that quotes 25dBA, 17CFM @ 2200RPM, 5VDC. 

Searching "5V DC fan" was highly informative. I am strongly considering picking up one of these amps, and these are the fans I would test.


----------



## NBPk402

DqMcClain said:


> I have ARCTIC F8 PWM PST fans in my HTPC chassis, and F10 fans as thermal exhaust for my rack cutout. They aren't completely silent, but they offer a very good ration of noise-to-airflow. I've also been happy with CoolerMaster Sickle-Flows, but I think the Arctic's beat them in noise-to-flow ratio in the 80mm category. (I'm not even sure at the moment if CoolerMaster makes that series in 80mm)
> 
> BONUS POINTS: The Arctics are on Amazon Prime.
> 
> EDIT: Looking closer at that pic, I see the motor on the fan says 5V. The F8 comes in a non-PWM controlled version that will run at 5V, but the airflow at that setting is not quoted. I found another fan by Gdstime that quotes 25dBA, 17CFM @ 2200RPM, 5VDC.
> 
> Searching "5V DC fan" was highly informative. I am strongly considering picking up one of these amps, and these are the fans I would test.


I wonder if anyone makes one that is thicker so the blades would be at more of an angle to get higher airflow...when the cardboard tube is removed you have 80mm of depth to play with.


----------



## NBPk402

DqMcClain said:


> I have ARCTIC F8 PWM PST fans in my HTPC chassis, and F10 fans as thermal exhaust for my rack cutout. They aren't completely silent, but they offer a very good ration of noise-to-airflow. I've also been happy with CoolerMaster Sickle-Flows, but I think the Arctic's beat them in noise-to-flow ratio in the 80mm category. (I'm not even sure at the moment if CoolerMaster makes that series in 80mm)
> 
> BONUS POINTS: The Arctics are on Amazon Prime.
> 
> EDIT: Looking closer at that pic, I see the motor on the fan says 5V. The F8 comes in a non-PWM controlled version that will run at 5V, but the airflow at that setting is not quoted. I found another fan by Gdstime that quotes 25dBA, 17CFM @ 2200RPM, 5VDC.
> 
> Searching "5V DC fan" was highly informative. I am strongly considering picking up one of these amps, and these are the fans I would test.


What do you think of this one?
http://www.amazon.com/noctua-NF-A4X10-FLX-5V-Noctua-Fan/dp/B00NEMGCIA

I researched and I got real close on the model number I found a AD0805HX-C70 instead of my C71...
Specs were:
5v
.40 current
5.16 power (W)
3010 rpm
27.3 cfm
3.25 static pressure
31.4 noise

The specs on the fan I found are(not sure how the noise compares as they are written diffently)... http://noctua.at/en/nf-a4x10-5v/specification


----------



## NBPk402

disregard i found out it won't do anywhere near the cfm of the stock one.


----------



## NBPk402

I think this one might be the ticket...
https://www.quietpc.com/gel-wing8-uvblue

Specifications	Wing 8 Fan
Air Flow (CFM)	28.1
Bearing	Nanoflux Bearing (NFB)
Cable Length (mm)	500
Connector	3-Pin
Current (A)	0.1
Dimensions (mm)	80 x 80 x 25
Fan Speed (RPM)	2000
Noise Level (dBA)	10 - 21
Safety Approvals	UL, CUL, CE, RoHS Compliant
Static Pressure (mmAq)	2.05
Voltage (V)	5
Accessories	Four rubber fan mounts and fan Resistor Cable
Weight (g)	68
Warranty	24 months


----------



## DqMcClain

So, the stock fan moves 27.3cfm, according to your research?

I'd bet that the fan they chose is set up such that it will dissipate the heat generated by running the amp at its rated power for extended periods... and I'd also bet that if you're using it as a surround/height/atmos channel amp, you'll be far enough under the rated power output that a minor variance in airflow won't cause you any real trouble. That Gelid Solutions fan looks pretty great for an 80mm 5V fan. It's pricey, and it's making a long trip to get to you... but that's going to be a very difficult fan to contend with.


----------



## NBPk402

DqMcClain said:


> So, the stock fan moves 27.3cfm, according to your research?
> 
> I'd bet that the fan they chose is set up such that it will dissipate the heat generated by running the amp at its rated power for extended periods... and I'd also bet that if you're using it as a surround/height/atmos channel amp, you'll be far enough under the rated power output that a minor variance in airflow won't cause you any real trouble. That Gelid Solutions fan looks pretty great for an 80mm 5V fan. It's pricey, and it's making a long trip to get to you... but that's going to be a very difficult fan to contend with.


Thanks, I am going to call Crest on Monday and see how low of a CFM fan will be ok. I am using the amps for all my speakers. My front channel horns are 112db, bass bins 100db, surrounds and Atmos are about 90db.


----------



## NBPk402

I really like this one, but it is a 12v...it is very quiet compared to my current one.
http://noctua.at/en/nf-r8-redux-1800/specification


----------



## lovinthehd

Going into the workshop today where I left the amp/packing materials, first sniff tells me the seller's moniker of seadog has something to it....
thanks for the headstart on fan research!


----------



## DqMcClain

Hmmm.... I wonder if these amps saw service at a beach resort (Club Med?) or on a cruise ship. It's not at all uncommon for large piles of old gear to end up on eBay after a company like these retires a show and specs a new rig for their showroom. 

I remember talking to an amp tech once that had received a pallet of Ashly amps that had been submerged in seawater after the resort where they were in use got hit by a hurricane. The impressive part was that after they washed all the crystallized salt off of the important inner-bits, they fired 'em up and every single one tested at factory spec. Hopefully "Seadog" either picked them up from a shop that checked them out, or he's a technician himself. Given that his other auctions are Luis Vuitton items, I kinda doubt he's a tech.


----------



## lovinthehd

I'm thinking any odors are more likely from the packing materials rather than where the amp was used BWK?


----------



## NBPk402

I decided to try this one...as it appears to pump out more CFM, and is 4db quieter than a brand new stock fan. We will see how it does/ It is thicker but I am going to make a new tunnel too. We looked at the tunnel and decided it needs to angle downward where the heat sink is on the amp...by doing this the theory is that all the air flow will hit the heat sink instead of saome flowing over it.
http://www.amazon.com/Gdstime-80mm-...id=1461702225&sr=1-2&keywords=Gdstime+80mm+5v

Package include: 1pcs fan 
Dimensions: 80x80x15mm 
Connector:XH2.54-2P 
Rated Voltage: DC:5V 
Rated Current: 0.3 Amp 
Rated Speed: 2700 RPM 
Air flow: 32.5 CFM 
Noise: 27 dBA 
Bearing Type: Sleeve 
Life: 35000 hours 
Cable Lenght: 25cm or 10 inches 
Weight: 48g


----------



## Tonto

So have you hooked it up to a source & listened to any music/movies?


----------



## NBPk402

Tonto said:


> So have you hooked it up to a source & listened to any music/movies?


No... I am waiting until the fans arrive.


----------



## NBPk402

lovinthehd said:


> Going into the workshop today where I left the amp/packing materials, first sniff tells me the seller's moniker of seadog has something to it....
> thanks for the headstart on fan research!


You might want to order some fuses in case one blows as they are not normal stock (in my area at least). They are an odd ball size. 3 amp 250v Littlefield 5x15 fuse Digikey part number F2454-ND. I am hoping that these are the right diameter. I only had a ruler to put them up against and they were a little bigger in diameter than 1/8". Also the stock fans are thicker than the replacement one i got, but the replacement was around 6db quieter.


----------



## lovinthehd

ellisr63 said:


> You might want to order some fuses in case one blows as they are not normal stock (in my area at least). They are an odd ball size. 3 amp 250v Littlefield 5x15 fuse Digikey part number F2454-ND. I am hoping that these are the right diameter. I only had a ruler to put them up against and they were a little bigger in diameter than 1/8". Also the stock fans are thicker than the replacement one i got, but the replacement was around 6db quieter.


Thanks about the fuse, still haven't even opened it up. Is it quiet enough for you now or will you continue to try and modify?


----------



## NBPk402

lovinthehd said:


> Thanks about the fuse, still haven't even opened it up. Is it quiet enough for you now or will you continue to try and modify?


I have new fans that are about 6db quieter, and appear to push more air, but I some how blew 2 fuses after repeated testing of fans. My new fuses should be in by Thursday...once they are in I will test the fans one last time before putting the amps back together.


----------



## NBPk402

Wait on the fuses...they might be ".3amp", not "3amp". I will post up when I verify.


----------



## NBPk402

I just called Crest Audio sales, and they said it is a 3amp fuse not a .3a fuse. They also said that there are 3 of them. The strange thing is they said there are 8 fuses in the amp, but I only see 3.


----------



## NBPk402

I received the fuses and they are 3Amp, and are also marked .3Amp. I installed them with the new fans. I hope to have them hooked up Friday or Saturday.


----------



## damianar1984

Hi, 

I just bought the CM2208 and I want to turn on/off each channel with a wifi switch like sonoff. I tried already the sonoff sv and the sonoff basic but it doesn't work. I thing the main problem is the 70.7Volt output per channel. Does anyone know how to solve the problem?

regards
damian


----------



## NBPk402

I use Insteon outdoor outlets to turn on and off my amps, but that is one outlet for each amp... I do not know how you would turn off individual channels on the same amp. Post up if you solve the problem.


----------



## mythbuster74

ellisr63 said:


> I use Insteon outdoor outlets to turn on and off my amps, but that is one outlet for each amp... I do not know how you would turn off individual channels on the same amp. Post up if you solve the problem.


So how have your amps been long term? Any issues? Dead channels?


----------



## NBPk402

mythbuster74 said:


> So how have your amps been long term? Any issues? Dead channels?


I ran them for several years like that with no issues.


----------



## mythbuster74

NBPk402 said:


> I ran them for several years like that with no issues.


How did you go from reciever to the amp? Can't really find and rca to phoenix for a decent price, so I guess I'll make my own?


----------

