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Soundstream Stealth ST4.1000D

Compact 4-channel car amplifier — 90 watts RMS x 4

16 Reviews | 3 questions - 8 answers

Overview

Our take on the Soundstream Stealth ST4.1000D

If you're in need of an amplifier that takes up liitle space but delivers a big sound, Soundstream's Stealth amplifiers can fill the bill. At about 3" deep by 7-1/2" wide, the ST4.1000D 4-channel amp will fit just about anywhere, delivering 90 watts per channel to your front and rear speakers, or up to 250 watts per channel in 2-channel mode to your subs. That's a lot of power in a tiny package.

Big sound, small package

If you're in need of an amplifier that takes up liitle space but delivers a big sound, Soundstream's Stealth amplifiers can fill the bill. At about 3" deep by 7-1/2" wide, the ST4.1000D 4-channel amp will fit just about anywhere, delivering 90 watts per channel to your front and rear speakers, or up to 250 watts per channel in 2-channel mode to your subs. That's a lot of power in a tiny package.

You're in control

The ST4.1000D also features high- and low-level inputs for a variety of applications, and includes high- and low-pass filters to help you tailor your sound. And Soundstream built this amp for the long haul with its MOSFET power supply and military-spec circuit board, surrounded by an aluminum alloy heatsink and guarded by full short-circuit, thermal, and overload protection circuitry.

Product Highlights:

  • 4-channel car amplifier
  • 90 watts RMS x 4 at 4 ohms (125 watts RMS x 4 at 2 ohms)
  • 250 watts x 2 bridged at 4 ohms
  • variable high- and low-pass filters (35-250 Hz, 12 dB/octave)
  • Class D amp technology
  • MOSFET power supply
  • preamp and speaker-level inputs
  • fuse rating: 30A x 1
  • 10-gauge power and ground leads recommended — wiring and hardware not included with amplifier
  • dimensions: 7-1/2"W x 1.5"H x 3-1/8"D
  • warranty: 1 year
  • Our 60-day money-back guarantee

Very small amp and easy to install under the seat. Have it powering door speakers.

matt, UT

What's in the Box:

  • 4-Channel Class D amplifier
  • One 30A ATM fuse (installed)
  • Two 8.25" Speaker-level input harnesses (with 5-pin Molex connector)
  • Two 6" Line-level input harnesses (Stereo female RCAs on one end and 5-pin Molex plug on other end)
  • 6" Speaker output harness (with 8-pin Molex connector)
  • 6" Power harness (with 6-pin Molex connector)
  • 4 Self-tapping screws (Length=5/8")
  • Owner's manual
Reviews

Soundstream Stealth ST4.1000D Reviews

Average Customer Review(s):

(16 Reviews)

Soundstream Stealth ST4.1000D

Jose from Viera, Fl. on 9/18/2017

Crutchfield Customer Review (What's this?)

This amp has plenty of power. However, it had a back grond noise from what seems to be auto turn on circuit. Followed the tech. Support recommendations. Gronding the speaker level leads only increases the noise. It creates a ground loop. (Engine wine). At high volume the music drowns the noise.

Pros: Compact, powerfull.

Cons: Noise

Great Power, Small Package

Lee from Georgia on 9/18/2017

Crutchfield Customer Review (What's this?)

Soundstream Stealth ST4.1000D I installed this into my 2006 Honda Accord. The stock headunit has practically no power. The previous owner had replaced the rear speakers with some Pioneer units and they barely worked with the factory radio. I decided I would try this small 4 channel amp. I have read reports that this amp does not have as much power as advertised. I do not know if this is accurate or not, but I am thoroughly impressed with the added speaker output following the installation. Installation is a bit dirty. You have to splice in all of the speaker wires to the amp. Finding power was a challenge as well, I ended up feeding it from a spare fuse location in the kickpanel fuse box. The wiring diagram supplied is not super clear and the word instructions I believe are for one of their other models. The instructions describe attaching a power cable to a lug terminal. This is not correct. All you have to do is tie the 2 power wires together and connect to one 12v source. After installation, I was a little disappointed. The amp did not seem to make much of a difference. That was until I found that the gain was turned ALL the way down. I currently have the gains about 2/3 turned up. The speaker out put is so loud, I am listening to music at radio volume 15 out of 40. Previously you had to turn the radio up to 36 or so before the rear speakers would have any drive. Overall, very impressed. Would recommend this product.

Pros: Good Power output. Good Speaker output increase. Small Package

Cons: instructions are not as good as desired slight hiss wiring is a bit sloppy.

Nice amp

matt from UT on 5/14/2017

Crutchfield Customer Review (What's this?)

Very small amp and easy to install under the seat. Have it powering door speakers.

Pros: Size, no engine noise

Cons: None so far

Soundstream Stealth ST4.1000D

AL from Heidelberg, MS on 3/27/2017

Crutchfield Customer Review (What's this?)

It does the job and the sound quality is good. I installed this on my Harley Electra Glide and its made a big difference in audio volume and sound. I have no problem hearing the music at highway Speeds and even when I crank it on my favorites it hang in there. Great size and power for the average or advanced audio buff.

Pros: Great size, Great sound and Good power for the size.

Cons: no Numbers on Crossover for accurate crossover frequency,

Soundstream Stealth ST4.1000D

gary j from Lucama, NC on 2/28/2017

Crutchfield Customer Review (What's this?)

Excellent bang for the money. Installed in my 2016 Dodge Challenger to drive my Polk Audio speakers and very surprised with the sound from a small Amp, just what the speakers needed. Very satisfied and again Tech support was right on the money. Thank you Crutchfield.

Pros: Great sound in such a small package.

Cons: None.

Hooked on Soundstream

Anonymous from Oshkosh, WI on 12/10/2016

Crutchfield Customer Review (What's this?)

Very impressed. This little thing has some serious juice. When hooked up on my Harley to an Aquatic Stereo, with Titan II (Biketronics) 7.1" in the front and JL 6x9's in the rear saddlebags, holy crap. Wish I would have dumped that stock stereo and hog tunes kit a long time ago. What an amazing difference. My first amp and I only had to call tech services once. I'm not an avid audio tech guy but the manual that comes with this thing leaves a lot to be desired. They don't tell you much of anything and in my opinion the directions/diagrams don't make things very easy. Now that's it's hooked up, it makes more sense to me, but I think I could write a better instruction manual. Overall, this thing is worth every penny. Highly recommend it.

Pros: Great output. Great Price. If you know anything about amps, probably not too hard to hook up.

Cons: If you don't know amps, the manual is very bad. If you know someone who knows about hooking up amps, have them stop by and explain it. Once you know what you are doing, it's pretty simple.

Soundstream Stealth ST4.1000D

Ken from Ojai, CA on 10/30/2016

Crutchfield Customer Review (What's this?)

Easy install, small and compact. Amp was installed in my jeep using the factory head unit with Polk audio speakers. Great sound all the way around.

Pros: Small and compact. Easy mounting and wiring,

Cons: none

Amplifier for VW Bug

Dale from Shelton, WA on 6/9/2016

Crutchfield Customer Review (What's this?)

Powerful amp in a small package. Fits perfectly in the small spot I created for it. I am using it to power a 10" sub and a set of 6.75" components. Easy installation and connections. Am bridging the rear channels for twice the power to the sub. Installation and hookup directions leave a little to be desired especially when bridging two channels. Ultimately very very happy with this amp!

Pros: Compact, price,

Cons: Wire hookups, installation instructions. Would have been nice to have spade type terminal connections, not bare wire connections.

good liitle amp

jake from Pennsylvania on 9/18/2015

So honestly I love this amp. I a mini cooper needed an amp i could hide in my car.The previous owner had the factory amp and head unit removed and ran a overlay harness from the crappy aftermarket headunit he had installed to patch into the speakers at the rear of the car where the factory amp used to be and didn't solder or crimp on a single wire(all wires just twisted together and taped). So my budget i tore that crappy work out and installed a kenwood headunit and speakers all around and put this amp where the factory amp would be. the only reason Im giving this 4 of 5 instead of 5 of 5 is the amp has static (gets worse the hotter the amp is) not a big deal on my amp because the static is not loud and is drowned out once my music starts playing but i read its worse on some other peoples amps.

Pros: small fits nearly anywhere. good sound for me

Cons: static bearable for me but if it gets worse will stat trying other small amps i have limited room

Great Amp

Keith from Memphis, TN. on 7/21/2015

Crutchfield Customer Review (What's this?)

Great little Amp. Work as advertised

Pros:

Cons:

great...

francisco r from Yonkers, NY on 4/14/2015

Crutchfield Customer Review (What's this?)

great ....

Pros:

Cons:

Great size, poor sound quality

Steve from Maine on 4/2/2015

Crutchfield Customer Review (What's this?)

This amp appealed to be because of the size and the price. It was easy to install and fit right under my seat. The only issue with it was the sound. I installed this amp to get a little more power to my speakers. What I got was a loud static noise. After trouble shooting with Crutchfield support (who were very friendly and knowledgable) I decided to take it to a local sound system shop. They installed it professionally, but the static sound is still there! They said that they don't endorse this brand because they have had bad experiences with their amps in the past. They said that my best bet is to either turn the gain all the way down so the hiss lowers, or buy an amp that is not shoddy quality. I am giving this amp the lowest rating because at the end of the day, adding unpleasant sounds to my music is absolutely unacceptable. It is a loud enough static that I can hear it quite distinctly even when playing my music loudly. I will be returning this one for sure and paying the extra money for a kenwood or something similar.

Pros: Small, Easy to install

Cons: Adds a loud and distinct hiss.

True RMS is much lower

Anonymous from Charlotte, NC on 8/26/2014

Amp is very nice and compact but doesn't put out anywhere near advertised. I tested it with a handful of frequencies 60Hz-8000Hz running output to four 4 ohm speakers and got between 45 and 55 watts before amp clipping. I knew it wouldn't put out what it said but didn't think it would be off by half. It has a 30 amp fuse, which is low for specified power output.

Pros: Small, easy to install in tight spaces

Cons: Power output isn't as advertised Power and ground connections are small and difficult to hook up

ALittle Gem

Soso from NJ, USA on 8/14/2014

Crutchfield Customer Review (What's this?)

I'm giving this little gem 5 stars. I had a Alpine KTP445U. That amplifier was good but after installing the Soundstream, I am more than satisfied with this product. I have MTX Thunder65 coaxial on all four of my doors. Those speakers are rated for 60watts RMS. I spoke to MTX support and asked if this amp, because its RMS rating is 90, would cause any damage to the speakers. He said as long as I adjust my gains to prevent clipping I wouldn't have a problem feeding the wattage the Soundstream would give out. I immediately noticed a more solid mid bass as well as cleaner vocals with this amplifier after raising the volume. I adjusted my gains using a SMD Distortion Detector playing track 4. Wiring was simple as I already had the wiring in place from the previous amp - the Alpine KTP445U. I placed the Soundstream behind and to the side of my glove box compartment under the dashboard. It fit snugly on a surface area with room around for breathing. I thought the Alpine was good but this Soundstream is a better choice. I like the ease of installation and its size. The size was the selling point as I didn't want to run wiring to the rear of my SUV. I used 10 gauge wiring for power and ground with a 30 amp fuse. I twisted the 2 power wires from the amp connectors together as well as the 2 ground wires, connected them to power and ground and off I went. This amp doesn't come with the orange wire shown in power connection picture

Pros:

Cons:

Great Amp For the Price

SoundStream Owner from PHX on 8/5/2014

Crutchfield Customer Review (What's this?)

I bought this amp, because I didn't have room to install an older JL Audio amp in my truck. I have it connected to Focal speakers in the front, MB Quart in the back, and a JVC media only head unit. For the money, i think it sounds amazing. I'm very picky about sound quality and wasn't disappointed.

Pros: -Size -Power -Mounting options -Sound Quality Give this amp a shot...you'll be surprised!!

Cons: A little disappointed in: - Power/Ground/Remote connections, but given the size of the amp, its acceptable. - Speaker connections are tiny...but, again..given the size of the amp, i can overlook that.

Cheaper than I expected

Radio-Upgrade from Round Rock, TX on 6/27/2014

Crutchfield Customer Review (What's this?)

When I unboxed the amp and looked at it, I was disappointed. I thought that the quality looked poor, and I decided not to install the unit.

Pros:

Cons:

Details

Hands-on research

Product Research

Features
Controls
Connections

Features

Overview: The Soundstream Stealth-series amplifiers pack a powerful punch from a small chassis. This 4-channel, full-range Class D amplifier can drive two pairs of speakers, or two subwoofers, without taking up a lot of space.

Power Output: The ST4.1000D micro-mini amp delivers 90 watts x 4 channels at 4 ohms, and 125 watts x 4 at 2 ohms. Bridged output is 250 watts x 2 (4 ohms).

High/Low Level Input: The amp includes plug-in harnesses for both high-level and low-level inputs. Speaker wires from the source unit can be spliced onto the two supplied high-level input harnesses. If you're using the preamp outputs from the source unit, you can plug in your RCA cables into the two low-level input harnesses. Both harnesses have a 5-pin Molex connector that plugs into the amp's Hi/Lo Input.

Note: If you're using the high-level inputs, you do not need to run a remote turn-on lead. The amplifier will automatically turn on when it senses an input signal.

LEDs: The amp features two LEDs to indicate the status of the amplifier. The green LED will glow when the power to the amplifier is on. When the red LED glows, the amplifier's protection circuitry is engaged, shutting down the amp.

Protection Circuitry: The protection circuitry will shut down the amplifier for the following conditions:

  • Overheating: Thermal protection can be caused by too low of an impedance or inadequate air flow around the amplifier.
  • Over-/Under-Voltage: The amp will shut down if the voltage to the amp is not within 10 to 16.8 Volts DC range.
  • Short Circuit: When speaker wires become shorted to each other or to the vehicle chassis, the amplifier will shut down.

Controls

Gain: The ST4.1000D's rotary gain controls let you match the amp's input sensitivity to the output of the source unit. There are independent gain controls for the front and rear channels of the amp. The input sensitivity range of the amplifier is continuously variable between 0.5V and 12V. A small screwdriver (not included) is required to set the gain.

Crossovers: The amp features independent 12 dB/octave crossovers that can be set to High-pass (HPF), Full Range, or Low-pass (LPF). The cutoff frequencies can be independently set between 35Hz and 250Hz using the rotary controls.

Connections

Molex Connections: The Soundstream ST4.1000D uses compact Molex connectors which plug into the amplifier for the amp's input, speaker output, and power/ground/remote turn-on connections.

Power: The Power/Ground/Remote harness contains two 16-gauge red +12V power wires. These should both be spliced to your power wire (not included) which runs from the amp to your battery. You should use at least a 10-gauge power wire to the battery, with an in-line 30A fuse no more than 18" from the battery terminal.

Ground: Like the power wires, there are two 16-gauge black ground wires. Both should be spliced to a larger gauge ground wire (not included) and attached to a metal area close to the amplifier. The ground wire should be the same gauge as the power wire.

Remote Turn-On: The blue wire in the power harness is for the amplifier's remote turn-on circuit. This should be spliced to a remote wire (18-gauge typically) that runs to the source unit. This connection is not needed if you are connecting the amplifier to the source unit via a high-level input.

High-Level Input: If you're connecting the amplifier to a factory head unit, or a unit that does not have preamp outputs, you should use the amp's high-level input. Splice the source unit's speaker wires to the two High-Level Input harnesses and plug them into the amp's Molex connectors.

Low-Level Input: The amp's two Low-Level input harness each have two female RCA connectors that will accept the plugs of an RCA patch cable from the head unit. The other end plugs into the amp's Molex connector.

Speaker Outputs: The amp features a speaker output harness with connections for 8 speakers. Speaker wires should be spliced onto the speaker output harness.

Our Product Research Team

At Crutchfield, you'll get detailed, accurate information that's hard to find elsewhere. That's because we have our own in-house Product Research team. They verify what’s in the box, check the owner's manual, and record dimensions, features and specs. We stay on top of new products and technologies to help people make informed choices.

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Q & A

Customer Q&A

Crutchfield asked  
Why did you buy this?

Looks to be great quality for price point.[ james  May 19, 2017 ]
Wanted more power than stock receiver delivers[ Brian  May 01, 2017 ]
Only amp that would fit in the space with this much power[ WARREN  Jan 31, 2017 ]
most watts I could find for that low of a price. bridge two channel and power an amp, and run more speakers with 90 watts a channel X 2 [ michael jonas  Mar 11, 2016 ]

3 questions already asked

Short answer:Yes, I would certainly think so, but I do not know from first-hand experience. My reasoning and instructions on how to complete the task are explained below, if you are interested. Also, I am unsure if this amp needs to be put into a "bridge mode" before bridging. Before doing so, I would ask one of the very-helpful Crutchfield technicians and have them confirm everything I have told you.Information:As is stated in the product's description, you can bridge 2 channels to attain 250 watts of power with 4 ohms of resistance. However, that is not stated to be RMS (which basically means the power at which it will run consistently), and what they mean by channel is not clearly stated. On this amplifier are 2 channels: front and rear. Technically, however, the front channel consists of two channels (left and right) and the rear is simply a duplicate of the front channel (making 4 channels total), as music is almost always recorded in 2.1 channels of audio (left and right), where the .1 means a subwoofer.Instructions:First, to complete this task, you need to transmit the correct information to the amp. You want subwoofer information, not speaker information. To do this, run an RCA cable from the sub-out port of your receiver/radio and plug them into the "rear channel" port of your amp. This will send only subwoofer information to the rear channel, which is what your sub, and you, will want. Also, on your amp, make sure your low-pass filter is set to a low frequency (around 30 Hz) and your high-pass filter is set somewhere around 80 Hz.Second, when bridging an amplifier, you connect the positive lead of Channel ONE (or left channel) to the positive terminal of the subwoofer. Then, you connect the negative lead of Channel TWO (or right channel) to the negative terminal of the subwoofer. My only concern for this amp is that the harness uses a small gage, like 20 AWG, and I fear it may struggle to allow enough current to transmit the higher power.[ James  Jan 21, 2016 ]
Short answer:Yes, I would certainly think so, but I do not know from first-hand experience. My reasoning and instructions on how to complete the task are explained below, if you are interested. Also, I am unsure if this amp needs to be put into a "bridge mode" before bridging. Before doing so, I would ask one of the very-helpful Crutchfield technicians and have them confirm everything I have told you.Information:As is stated in the product's description, you can bridge 2 channels to attain 250 watts of power with 4 ohms of resistance. However, that is not stated to be RMS (which basically means the power at which it will run consistently), and what they mean by channel is not clearly stated. On this amplifier are 2 channels: front and rear. Technically, however, the front channel consists of two channels (left and right) and the rear is simply a duplicate of the front channel (making 4 channels total), as music is almost always recorded in 2.1 channels of audio (left and right), where the .1 means a subwoofer.Instructions:First, to complete this task, you need to transmit the correct information to the amp. You want subwoofer information, not speaker information. To do this, run RCA cables from the sub-out port of your receiver/radio and plug them into the "rear channel" port of your amp. This will send only subwoofer information to the rear channel, which is what your sub, and you, will want. Also, on your amp, make sure your low-pass filter is set to a low frequency (around 30 Hz) and your high-pass filter is set somewhere around 80 Hz.Second, when bridging an amplifier, you connect the positive lead of Channel ONE (or left channel) to the positive terminal of the subwoofer. Then, you connect the negative lead of Channel TWO (or right channel) to the negative terminal of the subwoofer. My only concern for this amp is that the harness uses a small gage, like 20 AWG, and I fear it may struggle to allow enough current to transmit the higher power.[ James  Jan 21, 2016 ]
Provided your subwoofer configuration presents a minimum 4 Ohm load to the bridged channel, yes, you can use this amplifier in the configuration you've described. I hope that helps! My Bio: http://www.crutchfield.com/Support/Bio.aspx?bio=5 [ Ryan  Jan 20, 2016 ]  Staff
Yes, that is the easy way. However, there is a trick you can try if you only have 1 set of outputs from your headunit (a single left & Right output), you could use Male RCA Y-spliters to turn your single stereo R & L channels into 2 L & 2 R channels. You would not have a front to rear fader in this alternative set up but it is worth a try if you are limited to a single set of stereo outputs on your head unit. At least it would give you 4 channels... Obviously, if you have both a front and a rear set of Stereo channels on your headunits output, that is the best way to go because you could use a fader from front to rear with 4 independent channels[ B  Jan 02, 2016 ]
yes[ michael jonas  Jan 02, 2016 ]
yes, the amp will only produce amplified signals (output) on the same channels that are receiving frequencies (input) via RCA cable or high voltage signals[ michael jonas  Jan 02, 2016 ]
Here's the deal. This is a $140 amp, and if you buy it thinking that you're going to get the same type of power output as a 1000 watt amp that weighs 40 lbs and costs a thousand dollars, you're going to be disappointed. That said, it's a solid little amp than has been bumping along in my little 40 year old Datsun 240Z for the past three months, pushing enough power to overcome a significant amount of road noise. Output is clean, and the noise floor is low enough to not be audible when the car is running. I'd guess that it's probably pushing 200 real-world watts, which, if you feed it clean signal and use it with high-quality, efficient drivers, should be enough to make you happy.[ Scott  Jun 24, 2015 ]
We have not received any answers from other customers on your question. I would recommend reaching out to an Advisor by phone (1-800-324-9695) or online chat. They should be able to help answer your question.[ Krissy  Jul 09, 2014 ]  Staff
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