A cold exhaust is not the same instrument as a hot one. Clearances are at their largest, the metal is stiff, and any condensation sitting in the system damps the sound. The note is usually tighter and thinner than it will be later, and it can sound almost harsh on a cold morning.
Many owners judge a system in the first minute after start-up and then form an opinion that never changes. That is a mistake, because the characteristic tone of an exhaust is the one it holds once it has reached working temperature under load.
As the metal heats it expands, which closes the clearances in slip joints and changes how tightly the sections are coupled. Damping changes too, because a hot, expanded tube rings differently from a cold one. The result is a fuller, rounder note with more body through the mid range.
At the same time the gas itself changes. Hotter gas moves faster and carries its sound differently, and the pipe surface stops condensing moisture. Both effects push the tone toward the sound the system was actually designed to make.
Titanium expands further than stainless steel for the same rise in temperature, so the same joints move more as the system warms. That greater movement is one reason the difference between cold and hot tone can be more obvious on a titanium system than on a comparable stainless one.
It also means the design has to allow for it. A titanium exhaust with the same restraint as a stainless build will bind sooner, which is why hanger placement and flex sections are not simply interchangeable between the two materials.
Muffler packing is at its least effective when it is cold and damp. Overnight condensation sits in the fibrous material and absorbs sound, so a cold start can sound louder and coarser than the same system will five minutes later.
Once the system is hot the moisture is driven off and the packing works as intended. This is a normal effect, and it is one reason short trips make an exhaust sound permanently worse than long ones, because the system rarely spends long at a stable temperature.
Wall thickness, pipe diameter, the number and radius of bends and the internal layout of the muffler all set the character. Thinner walls radiate more high frequency, larger diameters deepen the note and can add low-speed drone, and equal-length routing smooths the pulses reaching the collector.
None of these can be judged in isolation, because a change that helps one part of the range usually costs something elsewhere. That is why a complete titanium exhaust system built as one piece tends to sound more coherent than a mixture of parts from different sources.
Listen to a system hot, at steady cruise, on part throttle and on the overrun. Cold-start volume matters to neighbours, but it is not the tone. A fair judgement needs at least one long drive rather than a lap of the block.
It also helps to know what the alternative really sounds like. A stainless steel exhaust system has its own character, generally a harder and more metallic edge, and that difference is a matter of preference rather than quality.
