El altavoz suena mejor cuando lo conecto al portátil.

Because lo refers to el altavoz, and altavoz is a masculine singular noun.

• el altavoz → masculine singular
• direct object pronoun for masculine singular → lo

So:

• Conecto el altavoz → Lo conecto

If the noun were feminine, you would use la instead:

• La radio → La conecto

Suena mejor means sounds better.

The verb sonar means to sound. In this sentence, it describes the quality of the audio coming from the speaker.

• El altavoz suena bien = The speaker sounds good
• El altavoz suena mejor = The speaker sounds better

Spanish uses sonar in a very natural way here, just like English uses sound.

Because Spanish often uses the simple present for general situations, habits, and normal statements.

Here, the sentence is expressing a general fact or repeated experience:

• El altavoz suena mejor cuando lo conecto al portátil
  = The speaker sounds better when I connect it to the laptop

Using está sonando would make it sound more like something happening right now at this exact moment, which is not the main idea here.

So:

• suena = sounds / does sound
• está sonando = is sounding

In this sentence, suena is the natural choice.

Because the sentence is talking about a habitual or general situation, not one single past event.

Conecto means I connect. The ending -o shows that the subject is I.

So the sentence means something like:

• It sounds better whenever I connect it to the laptop
• It sounds better when I connect it to the laptop

Spanish often uses the present tense in this kind of statement, just like English does.

Because Spanish often drops subject pronouns when the verb ending already makes the subject clear.

• conecto = I connect
• conectas = you connect
• conecta = he/she/it connects

So yo conecto is possible, but usually unnecessary unless you want emphasis or contrast.

Here, conecto already clearly means I connect, so yo is omitted.

Cuando means when.

It introduces the clause cuando lo conecto al portátil, which explains under what condition the speaker sounds better.

So the structure is:

• El altavoz suena mejor = The speaker sounds better
• cuando lo conecto al portátil = when I connect it to the laptop

Together, it means the improvement happens when that action occurs.

Because this sentence refers to a real, habitual, or known situation.

When cuando talks about something that regularly happens or is generally true, Spanish uses the indicative:

• Cuando lo conecto al portátil, suena mejor

If you were talking about a future event that has not happened yet, Spanish often uses the subjunctive:

• Cuando lo conecte al portátil, te avisaré
  = When I connect it to the laptop, I’ll let you know

So in your sentence, the indicative conecto is used because it describes a usual fact.

In Spanish, object pronouns like lo, la, los, las usually go before a conjugated verb.

So:

• Lo conecto = I connect it

That is why you get:

• cuando lo conecto al portátil

Not:

• cuando conecto lo ❌

With an infinitive or gerund, pronouns can attach to the end instead:

• Quiero conectarlo
• Estoy conectándolo

But with the conjugated form conecto, the normal position is before the verb: lo conecto.

Al portátil means to the laptop.

Al is the contraction of:

• a + el = al

So:

• conectar algo al portátil = to connect something to the laptop

This contraction is mandatory in normal Spanish:

• a el portátil ❌
• al portátil ✅

This only happens with a + el.
It does not happen with a la:

• a la televisión
• a la pantalla

In Spain, portátil is a very common word for laptop.

Literally, it means portable, but in everyday Spanish from Spain, el portátil usually means the laptop.

So:

• ordenador portátil = portable computer / laptop
• portátil = laptop

In other Spanish-speaking regions, people may also say things like:

• laptop
• computadora portátil
• ordenador portátil

But in Spain, portátil is extremely natural.

Yes, but then you would normally repeat the noun:

• El altavoz suena mejor cuando conecto el altavoz al portátil

Grammatically possible, but it sounds repetitive and unnatural.

Spanish, like English, usually prefers a pronoun once the object is already known:

• El altavoz suena mejor cuando lo conecto al portátil

That is much more natural.

Because el altavoz is the thing being talked about. It is the subject of suena.

The basic structure is:

• El altavoz = subject
• suena = verb
• mejor = adverb
• cuando lo conecto al portátil = time/condition clause

Starting with El altavoz makes it clear right away what is doing the sounding.

Yes. In this sentence, altavoz means speaker as an audio device.

It is a common word for a loudspeaker or speaker unit.

Depending on context, English might say:

• speaker
• loudspeaker
• external speaker

But speaker is the most natural translation here.

The meaning is basically the same, but the preposition pattern is worth noticing.

Spanish uses:

• conectar algo a algo
• conectar el altavoz al portátil

English uses:

• connect something to something

So when learning Spanish, it helps to remember:

• connect to in English
• conectar a in Spanish

That is why the sentence has al portátil.