Madrid: Safe, quiet hostal with Internet?

Hello!

I am travelling to Madrid for 5 days, and I'm looking for a "not too expensive" accommodation (probably hostel).

I have found the followings which I think best fit my expectations:

Hostal Acapulco
Hostal Benamar
Hostal La Perla Asturiana
Hostal Residencia Principado
Hostal San Martin

About some of them, I found reviews here, but for example about Hostal Benamar and Hostal SAN Martin I couldn't find anything.

For me, quietness, safety are very important, and I don't have a laptop, so I would need a place where there is computer for Internet as well.

Thank you for help.

Regards,
SzP

Just so you know, Hostal San Martín is not in the city of Madrid at all. It's in the village of San Martín de la Vega in the "province" of Madrid, about a 40 minute drive south from the city of Madrid. (the city and province have the same name - Madrid) It's also the location of the Warner Brothers Amusement Park.

Saludos, MadridMan

Yes, you're right, I found some confusions. Maybe I should have written "San Martin Guesthouse" (Concepcion Arenal in Madrid centre), this is what I thought. (But I saw it called as San Martin Hostal at some sites as well.)

Does anybody have info about this hostel or Hostal Benamar?