Selecting a budget amp

[gironja]

Hello!

I have been doing some research for around 2 weeks now, and still have not found a solution that satisfy my mind. Also, I want to apologize in advance for any grammar/language mistake, as English is not my main language.

I received a pair of Yamaha NS-AW194 speakers. They are rated for 30W nominal, 80W maximum. The amplifier I am looking is to drive them in my garage (20'x20'x(9.4' + 4.6' in a 4-side pyramid shape)), and preferably have Bluetooth connection. Keep in mind that while I work in my garage, its door is opened, and I also do a lot of work in front of it, so I am expecting sound waves to leave the enclosed area and still are enjoyable. In addition, I am not in a position right now to spend $100 on it. I should say that this first started looking at the Mo-Gu F900. And that price looked awesome! But at what expense?

Many years ago I used to be into car audio, and still today I am a music enthusiast. Therefore, I still want to have some quality or less noise/distortion as possible. However, This would be a work environment music system, not something that I would sit and relax/enjoy/over-analyze. In my times installing car audio, I learned things that have me now thinking about the cheap amps available right now.

Below are the amps I am considering:

• 
  ■Lepai LP1601s:
  2x 160W @ 4 ohm, 2x 100 W @ 8 Ohm
  BT: aptX
  ■Lepai LP7498E:
  2x 160W @ 4 ohm, 2x 100 W @ 8 Ohm
  BT: A2DP
  ■Fosi BT20A:
  2x 100W @ 4 ohm
  BT: not specified
  ■Dayton Audio DTA-120BT:
  2x 60W @ 4 Ohm, 2x 40W @ 8 ohm
  BT: aptX

Although price is very similar (except Fosi, which is cheaper), the main differences I am seeing are:

• 
  - DTA have 3.5mm Aux In and 1/4" out; LP16 have 3.5mm out; LP74 and BT20A none.
  - DTA switches in the knob; rest of them in an independent switch.
  - DTA switches audio when you disconnect BT; Lepai have discrete switch; Fosi is not specified.
  - DTA have some accesories (banana plugs, cables); rest don't.
  - Fosi have bass and treble controls; rest none.

If an amp with no bluetooth connection is selected, I might opt to get the Logitech Bluetooth Receiver.

Now, my main questions and concerns, and this is how I have been visualizing and making my calculation in my mind. Most of the amps have a THD of about 10% at their maximum outputs. Therefore, If I were to expect a high volume from the speakers, with the less distortion possible, then I would need an amp that can move the speakers without having to reach its limits (amp side). That is why I am thinking on going over the 30W nominal that the speakers are made for, since distortion increases in the amp's output as its output power increases.

However, I have seen a lot of good reviews and people talking good things about cheaper and lower output power amps, and I wonder if my mental calculations are wrong, and what I am confusing. I can say that I have not sat with a notebook and equations and a calculator. I am just throwing numbers per what I have seen when installing and choosing components for car audio. If someone wanted a loud system, you matched or went over the speaker (say, 4x 50W speakers, matched with a 300W 4ch amp, giving you 75WPC, and set its output to less than 2/3, providing almost speaker limit with less than 2/3 capacity). Nevertheless, I should say that those days were around 12 years ago, so I am very rusty.

Since I know there are a lot of people here with lots of knowledge, I would like your inputs. What would be good amp requirements, or how should I select those requirements based on the information I have in hand (speakers specs and room dimensions)? Based on your experience, what would be a good amp recommendation that could meet my needs?

Thanks in advance for your help and support!


Jonathan

 

[americanaudiophile]

Thank you for the links.
Your thoughts and calculations aren't wrong. I would want at least the 80w max that the speakers are rated to handle. They may not play loud enough with any amp. You would want a much more efficient speaker (above 90db for 1 watt) to be able to use a low powered amp and get any decent volume.
The power ratings on this type of cheap digital amp is usually inaccurate and, as you mention, given at very high distortion. To get below audible THD the amp may only produce 20-30% of its rated power rating. Given the size of your space and the openings you would likely damage the tweeters in the speakers when the amps clip.
Something like this
https/www.bestbuy.com/site/insignia-200w-2-0-ch-stereo-receiver-black/4156007.p?skuId=4156007
would be much better.
Almost any used receiver or integrated amplifier will sound better and likely be more powerful than any of the cheap digital amps. Older AVRs that are out of date for surround sound will be fairly cheap.
Of the ones you link to I would go with the Dayton Audio.

 

[gironja]

americanaudiophile thanks for your words!

My apologies for the long delay; I thought I was going to receive notifications, but they didn't come, and the project needed to stop for other priorities, so I forgot completely about it.

I understand your thoughts, and I will look for a receiver similar to the one you posted. I like the idea of the "outdated" ones, as I am looking for 2.0 sound, not more than that. I will be looking for a Bluetooth adapter that could have AptX (maybe similar to this, although it will defeat the "budget" part...)

Again, thanks for your inputs!

 

[punkncat]

For your application, I would give that Mo-Gu a chance. It's $32 shipped.
I would likely cut the rated power down at least half or a bit less. It would be reasonable to consider it putting out 15 or so mostly distortion free watts which should be plenty for "garage sound". I am sure you realize those speakers aren't going to put out significant bass, so why waste on wattage for it?
In respect to that, yes you could put more money into this, but for connecting to your phone and selecting a reasonable volume limit on the amp module I think it would be hard to beat that price. If it doesn't work out it wasn't enough to worry about.

 

[gironja]

To be honest, that Mo-Gu was the starting point on this. A coworker also got the same speakers (part of the 10-year service reward catalog), and he was looking into it, with a similar approach; mine is a garage, but his is a terrace. His music tastes are lighter than mines (soft rock, jazz, etc. vs going up to power/thrash/progressive metal).

I do realize I will not be receiving too much bass from them. My wattage analysis is mostly towards sound quality, given the significant loss I will have from the system + environment.

But your suggestion is well received! As you said, it would not hurt that much to try with a $32.99 part.

Thanks!

 

[punkncat]

Something else to consider if you are looking for something with a bit more quality and reality in the outputs would be to consider CL and a used receiver. You can purchase a line level Bluetooth module to add, but that would be scales more cost than this simple solution.

I mean, in reality you look at that thing and realize that without even appropriate heat sinks you KNOW it isn't putting out 50W x 2.

 

[gironja]

Yes... there is no way that would dissipate the heat that it will produce. And you look at receivers like the one americanaudiophile shared, and, besides components and manufacturing quality, there is also air flow and heat dissipation. I am very aware of it.

What do you mean by CL?

 

[punkncat]

craigslist

 

[gironja]

Got it! That's why it was not familiar... we don't have Craig List (at least not that popular as US) in Puerto Rico. I do am looking for a receiver in our main classifieds pages.

Thanks all for the inputs!